WO1992010912A1

WO1992010912A1 - Rental unit controller system

Info

Publication number: WO1992010912A1
Application number: PCT/US1991/009090
Authority: WO
Inventors: Steven J. Davis; Lawrence J. Karr; John Ward
Original assignee: Remote Deactivators, Ltd.
Priority date: 1990-12-06
Filing date: 1991-12-03
Publication date: 1992-06-25
Also published as: MX9102435A; AU9143191A

Abstract

A rental unit control system is provided which comprises a computer system (16) resident in a particular rental unit dealership (14). A rental unit deactivator circuit (10) is disposed within each rental appliance unit (12). Rental unit deactivator (10) comprises an FM receiver unit (24). FM receiver (24) receives control commands transmitted by an FM radio station (22) through an antenna (28). The FM transmissions are passed through a hi-pass filter (30) into a subcarrier demodulator (32). A microprocessor control unit (34) discerns whether a particular rental appliance unit (12) has been addressed and controls a switch (36) to selectively enable or disable the rental appliance unit. Computer system (16) within the rental unit dealership (14) is provided with software accounting systems, database management systems and transmission control systems which allow for the efficient management of a large number of rental appliance units rented by the particular dealership (14).

Description

RENTAL UNIT CONTROLLER SYSTEM

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to the field of electronic systems and more particularly to an improved rental unit controller system.

BACKGROUND OF THE INVENTION

The consumer electronics industry is one of the largest and fastest growing industries in the world. A lucrative market has developed for the rental of consumer electronic devices. A variety of franchise operations have developed offering pure rental of devices or rent- to-own programs of a variety of consumer electronic devices. The most commonly rented devices from these establishments are televisions, home stereos, video cameras and the like. Because of the nature of the items rented by these establishments, these businesses have had a problem with attempting to repossess items from customers who have let their accounts become delinquent. Rental businesses have thus suffered losses from stolen ^~ articles as well as the man. hours spent in attempting to receive the delinquent payments or repossess the rented goods.

The idea of remote deactivation of consumer electronics has been used in other contexts with tremendous success. For example, cable television companies have had the ability to deactivate cable descrambler units by sending selected signals through the cable which connects the cable company office to the consumer's home. Once a consumer has lost the use of the rented unit, he is obviously much more likely to update his account or return the rented unit. Until recently, there has been no way to apply this remote deactivation concept to general consumer electronic units because there was no general medium of transmission of the deactivation commands.

The advent of global paging networks has provided a medium which can be used to achieve the remote activation and deactivation of rented consumer electronic units. While it is believed there have been some attempts to apply global paging networks to accomplish the remote deactivation functions, these attempts have not successfully dealt with a variety of problems associated with a rental unit franchise operation. For example, there are two general types of global paging networks in use presently. The first type is a dedicated satellite- based paging network, which is characterized by dedicated transmitters located in each of the locales to be accessed by the network. The second type is commonly referred to as a subcarrier-based network and is characterized by the paging signals being carried on subcarrier transmissions such as those transmitted by FM radio stations. Prior attempts to utilize global paging networks to accomplish the remote deactivation function have primarily focused on the use of the dedicated paging networks. For this reason, these attempts have been unsuccessful as the costs associated with the deactivation units is prohibitive for a large scale rental operation.

Further, no prior attempts to accomplish the remote deactivation function have successfully integrated the deactivation function with the general operating computer system of the rental business. In order for a rental unit deactivation system to be commercially feasible and successful, it must be fully integrated into the existing accounting and management systems used by a particular franchise owner of a rental business. While subcarrier transmission networks have been used for data transmission in other contexts, an integrated system allowing for accounting functions, database management and remote deactivation has never been implemented.

Further, a need has arisen for a rental unit which is relatively undβtβctable by the customer. The placement of a conventional pager unit within a consumer electronic device can easily be detected by a relatively skilled consumer. Accordingly, the embodiment of the necessary circuitries within the consumer electronic device using surface-mounted technology provides not only for a reduction in the unit cost of the system, but also provides that the rental unit controller circuitry located within the consumer electronic device will be relatively undetectable by the consumer himself.

SUMMARY OF THE INVENTION

In accordance with the present invention, a rental unit controller unit is provided which substantially eliminates or reduces disadvantages and problems associated with prior systems attempting to accomplish the rental unit deactivation function, specifically, a rental unit controller system is provided which comprises a rental unit deactivator unit located within the housing of a particular consumer electronic device. The rental unit deactivator responds to commands received on an FM subcarrier transmission and selectively activates or deactivates the consumer electronic device. The rental unit deactivator itself comprises an FM receiver and a subcarrier demodulator which are each controlled by a microprocessor control circuit. In addition, software systems are provided to integrate the rental unit deactivation function with the remaining functions of a rental unit dealership. The necessary information to deactivate a rental unit can be identified by an accounting system, retrieved from a data base storage system and the data can then be transmitted from the integrated system for transmission over the FM subcarrier frequency by the paging company.

An important technical advantage of the system of the present invention inheres in the fact that the rental unit deactivator resident with the consumer electronic device utilizes surface-mount technology so that it is relatively undetectable by the consumer. In addition, the use of surface-mount technology provides for a significant cost savings when compared with the relatively high cost of a discrete pager unit.

An additional technical advantage of the present invention inheres in the fact that the software systems of the present invention utilizes a subcarrier-based paging network for the transmission of the activation and deactivation commands. The subcarrier paging networks provide for a efficient global network for the transmission of the pager command as well as providing significant cost savings per unit. An additional technical advantage of the present invention inheres in the fact that the software systems including both accounting systems and database management systems can be used to compile the necessary information to be sent to the paging company. The user of the system may selectively transmit single accounts immediately or automatically or manually compile a batch file of accounts to be transmitted to the paging company at a later date. In this manner, rental units can be selectively activated and deactivated immediately if necessary or large numbers of the rental units may be activated and deactivated at a later time in order to capitalize on periods of low use in the paging network.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be acquired by referring to the detailed description and the claims when considered in connection with the accompanying drawings in which like reference numbers indicate like features and wherein:

FIGURE 1 is a functional block diagram illustrating the operation of the rental unit control system of the present invention; FIGURE 2 is a functional block diagram of the rental unit deactivator circuit used in conjunction with the teachings of the present invention;

FIGURES 3A through 3C are schematic diagrams of one embodiment of the rental unit deactivator used in conjunction with the teachings of the present invention; and

FIGURE 4 is a flow diagram illustrating the operation of the software systems used to control the rental unit control function in accordance with the teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTipM

FIGURE 1 is a functional block diagram which illustrates the operation of the rental unit control system of the present invention. In general, a rental unit deactivator 10 is disposed within a rental appliance unit 12. Rental appliance unit 12 may comprise, for example, a television, a home stereo, a video camcorder or the like. Rental appliance unit 12 is presumably within the home of a customer who rented rental appliance unit 12 from a rental unit dealership 14. Rental unit dealership 14 utilizes a computer 16 which may comprise, for example, a personal computer such as an IBM- compatible system or a mini-computer such as an IBM-36 computer system. Computer 16 contains the software operating systems necessary for the operation of the rental unit dealership business. For example, computer 16 can run inventory systems, accounting systems and other software systems necessary for the operation of the business. Computer system 16 also contains a software system which can interface with the accounting system to provide a listing of the delinquent accounts associated with the rental unit dealership 14. Computer 16 can also contain a data base software system which stores information such as the serial number of rental appliance unit 12 and an address associated with the individual rental unit deactivator 10. According to one embodiment of the present invention, an integrated accounting system can automatically identify delinquent accounts for deactivation and automatically create a file including the necessary information for deactivation of the electronic units associated with the delinquent accounts. In operation, if the customer who has rented rental appliance unit 12 from rental unit dealership 14 becomes delinquent in his payment, the computer 16 will notify the franchise owner of rental unit dealership 14 that the customer is delinquent. The dealership owner can then access the data base storage within computer system and retrieve the rental appliance unit serial number and the address code for the rental unit deactivator 10. This information can be organized in a transmission file which is sent using conventional modem communication through a telephone company central office 18 to a paging company office 20. The paging company office 20 is likewise linked to an FM radio station transmitter 22. The paging company 20 receives the address associated with rental unit deactivator 10 from computer 16 and transmits it to the FM radio station 22 which, likewise, transmits the encoded address from its FM transmitter. The rental unit deactivator 10 scans the 88 MHz to 108 MHz frequency range commonly associated with FM transmission and looks for signals transmitted by paging company 20 possibly including its individual encoded address. If it detects its address, it will look for a command to either enable or disable rental appliance unit 12. In this manner, a dealership owner of a rental unit dealership, such as rental unit dealership 14, may selectively enable or disable rental appliance units within the customer's home without having to enter the customer's homes or even contact the customer. In a business context, the customer will then usually contact rental unit dealership 14 regarding the disabled unit. The) dealership owner can take this opportunity to remedy the delinquent account.

In general, the system of the present invention utilizes a subcarrier paging system which, in effect, "piggy-backs" the paging signals on a conventional FM radio transmission. For example, a standard FM transmission is transmitted at a carrier wave frequency from 88 MHz to 108 MHz. The modulation frequency transmitted on the carrier wave frequency for the radio signals is generally in the range of 0 KHz to 53 KHz. The paging data may then be transmitted in a frequency range of 57 KHz without interfering with the conventional radio signals. In this manner, the paging signals can utilize the transmission capabilities of conventional FM radio stations to transmit data over an extremely wide geographic area without incurring the cost of a dedicated transmission network.

The rental unit deactivator 10 within the rental appliance unit 12 must first locate the appropriate carrier wave frequency containing the paging data signal. Secondly, the rental unit deactivator must filter the paging data signal from the remaining subcarrier signals. In the specific embodiment described previously, this is accomplished by filtering out the 57 KHz signal from the remaining lower frequency signals from approximately 0 KHz to 53 KHz.

FIGURE 2 is a block diagram of one embodiment of a rental unit deactivator 10 which may be used in conjunction with the teachings of the present invention. Rental unit deactivator 10 comprises an FM receiver unit 24. FM receiver unit 24 comprises a tuner unit 26. FM receiver unit 24 is capable of receiving conventional FM radio signals in a frequency range on the order of 88 MHz to 108 MHz via an antenna 28. Once FM receiver unit 24 has tuned into a particular FM radio signal with the help of tuner 26, it transmits this signal through a hi- pass filter 30. Hi-pass filter 30 functions to filter out modulated frequency on the order of 0 KHz to 20 KHz. The filtered signal is then transmitted to a subcarrier demodulator unit 32. Subcarrier demodulator unit 32 functions to extract the data signal from the filtered signal transmitted from hi-pass filter 30. This is accomplished by locking onto the phase of the approximately 57 KHz signal and converting the data signal into a convention square wave voltage signal at conventional logic voltage levels. The data signal is transmitted to a microprocessor control system 34. Microprocessor control system 34 receives the data signal and determines whether it matches the address associated with the particular appliance unit.

If the microprocessor control system 34 determines that the address within the data stream received from subcarrier demodulator 32 matches the address stored within microprocessor control system 34 associated with the particular rental appliance unit, the microprocessor control system transmits a signal to a switch 36 to either enable to disable the rental appliance unit 12. Microprocessor control system 34 also transmits a feedback signal to the subcarrier demodulator 32 to establish a phase-lock loop to enable the system 10 to lock onto the phase of the signal received by the FM receiver 24. Microprocessor control system 34 also controls the tuner 26 as it scans through the 88 MHz to 108 MHz frequency range. The tuner 26 also transmits to the microprocessor control system 34 the particular frequency to which it is tuned. The microprocessor control system 34 can thus store this frequency so that if power is lost, the scanning of the 88 MHz to 108 MHz range can begin with this frequency. In this manner, if the unit has not been moved out of the general locale of the) m radio station being utilized, the scanning function will not have to occur as the rental unit deactivator 10 will lock onto the appropriate frequency immediately upon receiving power.

FIGURES 3A through 3C are schematic diagrams of one embodiment of the remote deactivator unit 10. The FM receiver unit 24 comprises an FM tuner chip 38. FM tuner chip 38 is coupled through an ANT and a GND pin to an antenna and ground. FM tuner chip 38 is coupled to a 12 volt supply voltage through a 91 Ω resistor 40 and a 10 μF capacitor 42 as shown in FIGURE 3A. An automatic gain control pin or AGC pin of FM tuner chip 38 is coupled to ground through a 0.1 μF capacitor 44. FM tuner chip 38 functions to convert the FM radio signals received from the antenna to an IF frequency of 10.7 MHz. The 10.7 MHz signal is output through the IF OUT pin of FM tuner chip 38 into a ceramic filter 46. Ceramic filter 46 may comprise, for example, a CFSD SD 107M1-AO-10G 10.7 MHz ceramic filter manufactured by Toko. The output of ceramic filter 46 is input into the IF IN pin of a FM discriminator chip 48. FM discriminator chip 48 is coupled to the 12 volt power supply through a 56Ω resistor 50 and a 0.1 μF capacitor 52, as shown in FIGURE 3A. The 10.7 MHz signal received from ceramic filter 46 is coupled to ground through a 330Ω resistor 54 and a 0.1 μF capacitor 56. A 0.1 μF capacitor 58 is coupled between a BPAS and a BIAS pin of FM discriminator 48. The BIAS pin of FM discriminator 48 is coupled to the nodejoining resistor 54 and capacitor 56. A 22μH inductor 60 couples a 0 and a QIN pin of FM discriminator 48. A 3.9 KΩ resistor 62 couples the QIN pin to a REF pin of FM discriminator 48. One input of a quadrature detection coil 64 is also coupled to the QIN pin of FM discriminator 48. The other input of quadrature detection coil 64 is coupled to the REF pin of FM discriminator 48. Quadrature detection coil 64 may comprise, for example, a KACS-K585 HM quadrature detection coil manufacture by Toko. The REF pin of FM discriminator 48 is coupled to the AFC pin of FM discriminator 48 through a 10 KΩ resistor 66. The ASC pin of FM discriminator 48 is coupled to ground through a 10 μF capacitor 68. The A pin, the SQU pin, and the GND pins of FM discriminator 48 are all coupled to ground. The CIN pin of FM discriminator 48 is coupled to ground through a 10 KΩ resistor 70. The CIN pin of FM discriminator 48 is also coupled to ground through a 0.1 μF capacitor 72. The CIN pin of FM discriminator 48 is also coupled to the AGC pins of FM tuner chip 38 through a 33 KΩ resistor 74. The REF pin of FM discriminator 48 is coupled to ground through a o.i μF capacitor 76. The OUT pin of FM discriminator 48 is coupled to an input node 78 of hi-pass filter 30 through a 200 pF capacitor 80. Input node 78 is coupled to one input of a differential operational amplifier 82 through a 10 KΩ resistor 84. Input node 78 is coupled to the remaining input of differential operational amplifier 82 through a 200 pF capacitor 86. The second input of differential operational amplifier 82 is coupled to a +-f supply voltage through a 20 KΩ resistor 88. The first input of differential operation amplifier 82 is coupled to the +5 supply voltage through a 470 Ω resistor 90. As shown in FIGURE 3A, resistors 88 and 90 as well as the supply voltage are coupled to ground through a 10 μF capacitor 92. The first input to differential operational amplifier 82 is coupled to the output of differential operational amplifier 82 through a 10 KΩ resistor 94.

Hi-pass filter 30 functions to filter out the lowest 20 KHz of signal received from the FM discriminator 48. FM discriminator 48 outputs signals ranging from approximately 0 KHz to 57 KHz. Hi-pass filter 30 functions to reduce this frequency range to approximately 20 KHZ to 57 KHz. The output of amplifier 82 is coupled to a first input of a first hβtβrodynβr 96 through a o.l μF capacitor 98 shown in Figure 3B. The first input of first hetβrodynβr 96 is coupled to a first input of a second heterodyner 100. An output second of first heterodyner 96 is coupled to an output of second heterodyner 100 through a 4.7 KΩ resistor 102 and a 4.7 KΩ resistor 104. A node between resistors 102 and 104 is coupled to the +5 supply voltage. The output of first heterodyner 96 is coupled to ground through a 7.5 KΩ resistor 106 and a 0.01 μF capacitor 108. A node 110 between resistor 106 and capacitor 108 is coupled to a first input of a differential operational amplifier 112 through a 56 KΩ resistor 114 and a 56 KΩ resistor 116. A node between resistor 114 and 116 is coupled to a second input of operational amplifier 112 through a 1500 pF capacitor 118. The first input of differential operational amplifier 112 is coupled to ground through a 1,000 pF capacitor 117. The second input to differential operational amplifier 112 is coupled to the +5 supply voltage through a 1 KΩ resistor 120. The second input to differential operational amplifier 112 is coupled to the output of differential operational amplifier 112 through a 10 KΩ resistor 112. The output of differential operational amplifier 112 is coupled to a first input of a differential operational amplifier 124 through a 22 KΩ resistor 126 and a 22 KΩ resistor 128. A node between resistors 126 and 128 is coupled to the second input of operational amplifier 124 through a 0.01 μF capacitor 130. The second input of operational amplifier 124 is directly coupled to the output of operational amplifier 124. The first input of operational amplifier 124 is coupled to ground through a 1,000 pF capacitor 132. A first input of a differential operational amplifier 134 is coupled to the +5 supply voltage. The second input of operational amplifier 134 is coupled directly to the output of operational amplifier 124. The output of differential operational amplifier 134 is coupled to ground through a 10 KΩ resistor 136 and a 10 KΩ resistor 138. The output of operational amplifier 134 is also coupled to a driver input of a third heterodyner 140. A first input of third heterodyner 140' is coupled to the -5 supply voltage.

An output of second heterodyner 100 is coupled to ground through a 7.5 KΩ resistor 142 and a 0.01 μF capacitor 144. A node between resistor 142 and capacitor 144 is coupled to a first input of a differential operational amplifier 146 through a 56 KΩ resistor 148 and a 56 KΩ resistor 150. A node between resistor 148 and 150 is coupled to the +5 voltage supply through a 1500 pF capacitor 152 and a 1 KΩ resistor 154.

The first input of operational amplifier 146 is coupled to ground through a 1,000 pF capacitor 156. The operational amplifier 146 is also coupled to a +12 supply voltage and ground potential. The second input of operational amplifier 146 is coupled to a node between resistor 154 and capacitor 152 and is also coupled to the output of operational amplifier 146 through a 10 KΩ resistor 158. The output of operational amplifier 146 is coupled to a first input of an operational amplifier 160 through a 22 KΩ resistor 162 and a 22 KΩ resistor 164. A node between resistors 162 and 164 is coupled to the second input of operational amplifier 160 through a o.oi μF capacitor 166. The first input to operational amplifier 160 is coupled to ground through a 1,000 pF capacitor 168. The second input of operational amplifier 160 is directly coupled to the output of operational amplifier 160. The output of operational amplifier 160 is coupled to a first input of third heterodyner 140 through a 10 KΩ resistor 170. The first input of third heterodyner 140 is directly coupled to a first input of a differential operational amplifier 172. The output of operational amplifier 160 is coupled to a second input of operational amplifier 172 through a 10 KΩ resistor 174. The second input of operational amplifier 172 is coupled to the output of operational amplifier 172 through a 10 KΩ resistor 176. Operational amplifier 172 is also coupled directly to a +12 supply voltage and ground potential through additional pins. The +12 supply voltage is also coupled to ground potential through a 0.01 μF capacitor 178.

The +5 supply voltage is coupled to the first input of a differential operational amplifier 180. The output of differential operational amplifier 172 is coupled to the second input of operational amplifier 180 through a 10 KΩ resistor 182. The second input of operational amplifier 180 is coupled to ground through a 0.01 μF capacitor 184. The output of operational amplifier 180 is coupled to ground through a 10 KΩ resistor 186 and a 10 KΩ resistor 188. A node 190 between resistor 186 and resistor 188 supplies a phase feedback signal output from subcarrier demodulator 32 into microprocessor control unit 34. The driver input to first heterodyner 96 is supplied through a buffer 192 from the output of an exclusive-OR gate 194 shown in FIGURE 3C. The driver input of second heterodyner 100 is supplied through a buffer 196 from the S3 pin of a phase adder chip 198. The S3 pin of phase adder chip 198 also supplies one input of exclusive-OR gate 194. The S2 pin of phase adder 198 supplies the remaining input to exclusive-OR gate 194. The signals provided from buffers 192 and 196 to heterodyners 96 and 100, respectively, are each 57 KHz square wave signals which are 90* out of phase with respect to one another. Heterodyners 96 and 100 function as choppers to reduce the 57 KHz signal which is carrying a modulation signal on the order of ±3 KHz to a signal on the order of 0 KHz to 3 KHz. The remaining circuitry within subcarrier demodulator 32 comprise two parallel low-pass filters which filter out all signals above approximately 2500 Hz in frequency. The signals are then run through a half-linear multiplier comprising differential operation amplifier 172 and the surrounding circuitry and an averager comprising differential amplifier 180, resistor 182 and capacitor 184. The average signal of the two out-of-phase signals should be 0 when the signals are in phase with the signal received by FM receiver 24.

The phase feedback signal output from node 190 of subcarrier demodulator 32 is input into a G3/TI0 input of a microprocessor chip 200. Microprocessor chip 200 may comprise, for example, a COP 822 CN 8-bit microprocessor manufactured by National Semiconductor. Microprocessor chip 200 has its 8 data pins, L0 through L7, coupled as shown in FIGURE 3C to the Al through A4 inputs of phase adder chip 198 and a second phase adder chip 202. The C4 output of phase adder chip 202 is coupled to the CO input of phase adder 198. The CO input of phase adder chip 202 is coupled to ground. The Bl through B4 inputs of phase adder chip 202 are coupled respectively to the QA, QB, QC and QD outputs of a first counter 204. The Bl through B4 inputs of first phase adder chip 198 are similarly coupled to the Qλ, QB, QC and QD outputs of a second counter chip 206. The CLR pins of counter chips 204 and 206 are coupled to ground potential. The A pin of counter chip 206 is coupled to the 2D output of counter 204 and carries a 456 KHz square wave signal. The A pin of counter chip 204 carries a 7.296 MHz signal which is generated by a 7.296 MHz crystal 208. Crystal 208 has each of its nodes coupled to ground potential through 22 pF capacitors 210 and 212. One of the nodes of crystal 208 is directly coupled to the CKIN input of microprocessor 200. The second node of crystal 208 is coupled to the CKIN input of microprocessor 200 through a l MΩ resistor 214. This second node of crystal 208 is directly coupled to the CK0/G7 pin of microprocessor 200. The data is received by the microprocessor chip 200 from the subcarrier demodulator 32 through is GO/INT pin. The phase feedback signal from node 190 of subcarrier demodulator 32 is received by microprocessor 200 through the G3/TI0 pin. The microprocessor uses its data bus L0 through L7 to provide feedback to the phase adder which in turn provide the driver signals for heterodyners 96 and 100. This functions as a phase lock loop to insure that the subcarrier demodulator 32 is operating in phase with the signals received from FM receiver 24. A reset signal is provided to the RESET pin of microprocessor 200 by an exclusive-OR gate 216, which has a first input coupled to the VCC supply voltage, such that it functions to invert the signal at its second input received from an exclusive-OR gate 218. The first input of exclusive-OR gate 218 is coupled to the VCC supply voltage. A second input of the exclusive-OR gate 218 is coupled to ground potential through a 0.01 μF capacitor 220. The inputs of exclusive-OR gate 218 are coupled together through a 20 KΩ resistor 222. In this manner, when the VCC supply voltage is brought up after a power outage, a reset signal is supplied to the microprocessor 200.

The GND pin of microprocessor 200 is coupled to the ground potential and the VCC pin of microprocessor 200 is coupled to the VCC supply voltage, which is in turn coupled to ground potential through a 0.01 μF capacitor 224. The control signal to enable or disable a rental unit is output from microprocessor 200 through its Gl pin. This signal is rooted through a buffer 226 and a 10 KΩ resistor 228 to the base of an NPN bipolar transistor 230. The emitter of transistor 230 is coupled to ground potential. The collector of transistor 230 is coupled to the VCC supply voltage through a 1 KΩ resistor 232. The actual enable/disable signal is output from the collector of transistor 230 through a 470 Ω resistor 234. The transistor 230 functions to isolate t•_he system 10 from signals which might be transmitted back from the switch controlled by system ιo. Switch 36 can be made to control a variety of components within a particular rental appliance depending upon the nature of the appliance. For example, switch 36 could be used to disable all but the standby power within a rental television set.

Microprocessor 200 outputs serial data through its G4/S0 pin to a DATA pin of an FM synthesizer chip 236. The serial data line from microprocessor 200 is also coupled to the DI pin of a EEPROM chip 238. A clock signal is output from microprocessor 200 to the SK pin of EEPROM chip 238 and to the CLK pin of synthesizer chip 236 to clock data in and out of these devices.

Serial data is received from the EEPROM chip 238 through its DO pin into the G6/SI pin of microprocessor 200. A chip select signal is generated by microprocessor 200 and is output from the G2 pin into the CS pin of EEPROM 238. This chip select signal is also input into an input of an exclusive-OR gate 240. The second input of exclusive-OR gate 240 is coupled to the VCC supply voltage. The output of exclusive-OR gate 240 is input into the CE pin of synthesizer chip 236 and functions as a chip enable signal. EEPROM chip 238 is coupled to the VCC supply voltage and to ground. The VCC and GND pins or UPROM chip 238 are coupled to one another by a 0.1 μF capacitor 242. A 7.2 MHz crystal 244 is used to supply a clock signal to the XIN pin and the XOUT pin of synthesizer chip 236. Each node of the crystal 244 is coupled to ground potential through 15 pF capacitors 246 and 248. The GND pin of synthesizer chip 236 is coupled to ground potential.

The FM FIN pin of synthesizer chip 236 is coupled to the LO pin of FM tuner chip 38 through a 0.01 μF capacitor 250. The 3.5 - 6.5 pins of synthesizer chip 236 are both coupled to the VCC supply voltage. The VCC supply voltage is coupled to ground potential through a 0.01 μF capacitor 252. The FM PULSE pin of the synthesizer chip 236 is coupled to the gate of a field effect transistor 254 through a 1 KΩ resistor 256. The gate of transistor 254 is coupled to the source of transistor 254 through a 1 μF capacitor 258 and a 1 KΩ resistor 260. The drain of transistor 254 is coupled to ground potential. The source of transistor 254 is coupled to the CV pin of FM tuner chip 38 through a 10 KΩ resistor 262. The CV pin of FM tuner chip 38 is coupled to ground potential through a 0.01 μF capacitor 264. The source of transistor 254 is also coupled to +11 volts through a 3.3 KΩ resistor 266.

The EEPROM chip 238 functions to store the unique address associated with the particular rental unit. Chip 238 also stores the last station tuned to by the synthesizer chip 236 and the FM tuner chip 238. The synthesizer chip 236 will receive the frequency to be monitored from the microprocessor 200 and in conjunction with FM tuner 38 will monitor the selected frequency until instructed to scan to a different frequency by microprocessor 200. The enable/disable signal is output from system 10 through a connector 268. This same connector 268 is coupled to the +5 volt and +4 volt standby voltages in the consumer electronic unit. The +12 volt VCC voltage signal is derived from the +5 volt standby signal through a 39 Ω resistor 270. The VCC voltage signal is coupled to ground potential through a 10 μF capacitor 272. The +12 volt standby voltage signal is coupled to ground potential through a 10 μH inductor 274 and a 10 μF capacitor 276. The VSS and ground signals are also received through the connector 268. In operation, the microprocessor 200 simultaneously performs two basic functions. The first background function has been discussed previously with relation to the phase lock loop comprising microprocessor 200, clock chips 204 and 206, phase adders 202 and 198, and subcarrier demodulator 32. The phase lock loop formed by these components insures that the subcarrier demodulator 32 will operate in phase with the signals received by FM receiver 24. Microprocessor 200 also executes approximately a l kilobyte program which essentially scans the 88 MHz to 108 MHz frequency range attempting to locate the pager data FM channel. When power is first applied to microprocessor 200, the microprocessor 200 will be reset. Microprocessor 200 will retrieve from EEPROM 238 the last station the system was tuned to. The microprocessor 200 will then output this station to the synthesizer chip 236 which will cause the FM receiver 24 to tune to this station. The microprocessor 200 will then check the data input line received from subcarrier demodulator 32 to see if a hex code associated with the particular paging signal is being transmitted on that station. For example, the hex code associated with the Cue Paging Company is Hex B5. This signal is transmitted approximately every 100 milliseconds. If the microprocessor 200 does not find the requisite paging signal, it will institute a scanning procedure and scan the •• MHz to 108 MHz frequency range until it finds the proper signal. Once it is locked onto the appropriate paging signal, the microprocessor 200 will first store the frequency of the appropriate signal in the EEPROM chip 238. This frequency can then later be used as the last station tuned to if a power failure ever occurs. The microprocessor 200 will then enter a loop where it constantly looks for the particular address for the rental unit to be transmitted over the data stream. If it locates the appropriate address,' it will then look for the appropriate control command following the address and will manipulate the enable/disable signal accordingly. If the microprocessor 200 ever loses the constantly repeating paging signal such as the hex B5 signal, it will reinstitute the scanning procedure.

The EEPROM chip 238 can be initialized in a variety of ways. According to one embodiment of the system of the present invention, a permanent address is placed in the EEPROM chip 238 when the system 10 is manufactured. The individual address for a particular unit can then be downloaded into the EEPROM 238 by transmitting the permanent address and an access code to signal the microprocessor 200 to accept the new address. In the alternative, the individual addresses can be programmed into EEPROM chip 238 when the system is manufactured.

An important technical advantage of the system of the present invention inheres in the fact that system 10 is embodied in surface-mount technology. Accordingly, the circuitry comprising remote deactivator unit 10 can be "hidden" amongst other circuitry within a consumer electronic device. Additionally, the circuit described with reference to FIGURES 3A through 3C can be embodied in extremely compact circuitry so that it can be used in, for example, video camera equipment.

An important technical advantage of the system of the present invention is its user interface, which allows a dealership owner renting consumer electronic devices to members of the general public to easily keep track of and control the rental units in the field using existing management computer systems. As discussed previously with reference to FIGURE 1, the rental unit dealership usually has some sort of computer system 16. Computer system 16 may be used to perform accounting functions. inventory control or other similar functions. Computer system 16 may comprise a personal computer or a mini¬ computer.

FIGURE 4 is a flow diagram which illustrates the user interface of a data base management system which can be used by franchise owners of rental unit dealerships to control rental appliance units in the field. The database management system described in Figure 4 can be used in conjunction with an integrated accounting system to provide for the efficient management of many rented electronic devices. The database management systems of the present invention may be used by the accounting system to automatically compile files of delinquent accounts. A conventional accounting system can perform÷a variety of functions such as inventory control, retail sales as well as rental contract account maintenance. The accounting system may comprise, for example, the CRIS accounting system which is commercially available from Curtis Mathes Corporation of Athens, Texas. According to one embodiment of the present invention, the accounting system can automatically identify delinquent accounts associated with particular rented devices. The database management system can then retrieve the required information associated with the delinquent account and compile a transmission file to allow for the deactivation of the particular device. This integration between the accounting system and the database management system can be automatically accomplished in the operation of a personal computer or other computer system using known methods.

Referring to Figure 4, a data base management system, indicated generally at 280, begins with a main menu block 282. Main menu block 282 allows a user to select between a variety of functions. Among these functions are a data base maintenance block 284, a batch data input block 286, a batch transmission set up block 288, an immediate transmission block 290, a set time and day block 292 and a report generation block 294.

Data base maintenance block 284 allows a user to add, modify or delete data base records from the data base system of rental appliance systems managed by system 280. If a record is to be either added or deleted in block 296, a serial number and/or an address is retrieved from the user in block 298. If a record is to be added, both the serial number and the unique address associated with that unit must be added. The record is then added or deleted in block 300. The user can edit the existing records of a data base by selecting the modify feature in block 302. The user accesses a particular data base entry by entering either the serial number or the address and is allowed to modify the serial number or the address in block 304. The system 280 also displays for the user the current status of the unit as well as the date and time of the last status change. If the user changes either the serial number or the address, those changes are saved in block 306. The serial number of a particular unit may vary widely depending on the particular appliance involved. The unique logical address of the remote deactivation unit may comprise, for example, an 8 bit numeric value.

The user may construct a batch transmission file by selecting the batch data input 286. An important technical advantage of the system of the present invention inheres in the fact that the user may select to transmit a number of enable or disable commands at a predetermined time or may select to immediately enable or disable a unit. As described previously, the identification and compilation of required data associated with a number of electronic devices can be accomplished by the automatic interaction of the accounting system of the present invention and the database management systea 280. In the alternative, a number of units could be manually identified and compiled into a batch transmission by directly interacting with the database system 280. In order for a user to manually construct such a batch data transmission file, the serial numbers and/or the addresses of each unit to be affected are entered in block 308. The command for each unit is entered in block 310. Batch transmission files manually or automatically created are stored by the computer system 16 until the batch transmission time is reached. The batch transmission setup is configured by the user by selecting the batch transmission setup block 288. The user can then select to set a periodic transmission of batch transmission files in block 312 or can select to set up a one-time transmission of a batch transmission file in block 314. If the user selects block 312, the day of week and the time of day are set in block 316. If a one- time transmission is selected in block 314, the one-time date and time of the transmission are set in block 318. The user can also elect to cancel a batch transmission by selecting block 320. In this manner, the user can manually construct a batch transmission file comprising a number of addresses associated with a number of rental units with βnablement or disablement commands associated with each unit. In the alternative, the user can allow the accounting system of the present invention to automatically identify delinquent accounts and interact with database management system 280 to generate a batch transmission file. The user can elect to have the batch transmission file transmitted periodically at a preset day of the week and time of the week, or can set up a one-time transmission of the batch file. The periodic transmission of commands can capitalize on periods of low use in the paging network, for example, in the middle of the night.

System 280 also allows for the immediate control of a particular rental unit through the selection of the immediate transmission block 290. If the immediate transmission block 290 is selected, the user must enter the serial number or the address in block 322 and enter the desired enablement or disablement command in block 324. The system time and day can be set by selecting the set day and time block 292.

System 280 has the capability of generating a variety of reports by selecting the report generation block 294. If block 294 is selected, the user is asked to select in block 326 whether the user wishes to print or inquire into the data base, transmission or log files. The user is then asked whether he wishes the selected files to be sorted by the serial number or address in block 328. A user of system 280 can thus print or peruse the entire data base or just the transmission files.

These reports include both the serial number and address for each unit as well as the current status and date and time of last status change. The log files, which may be reported, are formed during the communication with the paging company and include any problems which might have occurred due to failures in the communication system. The control program 280 may be installed in the computer system 16 using a conventional DOS installation procedure. According to one specific embodiment of the systea 280, a configuration file is generated during the installation procedure containing the following data field. An input stream data field within the configuration ile contains the name to be used for the batch transmission files. A log file data field within the configuration file contains the name of the file to which the audit information generated during the communication protocol is written. A printer name field within the configuration file identifies the device to which all print output is routed by the system 280. The configuration file may also contain the telephone number used to dial the paging company using a

< modem contained within computer system 16. An access code may also be included such that the paging company can identify the particular dealership desiring access to the paging system. The configuration file must also contain a field identifying the communications port on the computer system 16 to which the modem is connected. The modem is further identified in the configuration file by its band rate, the- number of data bits in a transmitted character and whether odd or even parity and stop bits are used. A modem initialization string is also usually included. The configuration file may also include the dialing command to instruct the modem to dial a telephone number as well as the various responses the modem may return responsive to a successful or unsuccessful connection to the paging company. The configuration file can also contain the command string sent to the modem which causes it to disconnect from the paging company. The configuration file may also contain the amount of time allowed for a response to a command transmitted to the paging company. If the paging company doe* not acknowledge the receipt of an enablement or disablement command within the specified time period, the systea 280 will terminate and reschedule transmission of the command at a later time. The configuration file can also contain a number of attempts to reach the paging company. Unsuccessful attempts to reach the paging company or instances where the paging company does not reply within the allotted time period may be logged in the error log along with the serial number, address and command associated with the particular unit.

Accordingly, the software and hardware systems described herein allow for a dealership owner to efficiently manage a large number of rental units in the field. The dealership owner can immediately enable or disable a particular rental unit or can set up a batch transmission file to enable or disable a large number of units at a later time. The efficient interaction between accounting and database systems allows for efficient and accurate control of any number of units. The batch transmission feature may be used to take advantage of times when the paging network is not at peak usage, for example, in the middle of the night, to enable or disable rental units. Accordingly, a rental unit control system is provided which utilizes a subcarrier paging network and a microprocessor-controlled rental unit deactivator disposed in each rental unit to selectively enable or disable rental units in the homes of customers of a particular rental unit dealership. Software management systems are provided to allow for the efficient and accurate management of a large number of rental units. According to one embodiment of the rental unit deactivator, surface mount technology is used so that the rental unit deactivation circuit is relatively undetectable by the consumer.

Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

WHAT IS CLAIMED IS; l. A system for controlling remotely electronic devices, comprising: an accounting system operable to store a plurality of accounts associated with different electronic devices and further operable to identify ones of said accounts which are delinquent; a database system for storing a plurality of addresses, each of said addresses associated with a single electronic device; a selection system coupled to said database system and operable to select a particular address associated with a particular electronic device to be controlled remotely; transmission circuitry for transmitting to a subcarrier paging network said particular address and a control command; and a controller circuit resident in a particular one of the electronic devices to be controlled remotely and operable to receive a frequency modulated transmission from the subcarrier paging network, said transmission comprising said particular address associated with said particular one of the electronic devices and said control command, said controller circuit further operable to enable said particular one of the electronic devices responsive to the receipt of said particular address and a first control command, said controller circuit further operable to disable said particular one of the electronic devices responsive to the receipt of said particular address and a second control command.

2. The system of Claim 1 wherein said selection system is automatically responsive ^'to said accounting system to select addresses of devices associated with identified delinquent accounts.

3. The system of Claim 1 wherein said controller circuit comprises: an FM receiver circuit operable to receive frequency modulated transmissions; a subcarrier demodulator circuit coupled to said FM receiver circuit and operable to extract data transmissions from said transmissions received by said FM receiver circuit; a microprocessor control circuit coupled to said subcarrier demodulator circuit, said microprocessor control circuit operable to receive said data transmissions and to determine if said data transmissions are intended for said particular electronic device, said microprocessor further operable to generate a switch control signal responsive to the receipt of data transmissions intended for said particular electronic device; and a switch coupled to said electronic device and said switch control signal, said switch operable to selectively enable and disable said particular electronic device responsive to said switch control signal.

4. The system of Claim 3 wherein said microprocessor is coupled to said FM receiver circuit and is operable to cause said FM receiver circuit to scan through a predetermined frequency range until said data transmissions are detected by said microprocessor control circuit.

5. The system of Claim 4 wherein said microprocessor control circuit further comprises a memory circuit, said microprocessor control circuit operable to store a frequency value associated with a frequency on which said data transmissions are detected.

6. The system of claim 3 wiierein said microprocessor control circuit further comprises a memory circuit, said memory circuit operable to store said particular address associated with said particular electronic device, said microprocessor control circuit operable to search said data transmission for the presence of said particular address.

7. A method for controlling remotely electronic devices, comprising the steps of: storing a plurality of accounts associated with ones of the electronic devices; identifying ones of the accounts which are delinquent; storing a plurality of addresses, each of the addresses associated with a single electronic device; selecting, responsive to said step of identifying, a particular address associated with a particular electronic device to be controlled remotely; transmitting to a subcarrier paging network the particular address and a control command; and receiving a frequency modulated transmission froa the subcarrier paging network using a controller circuit resident in a particular one of the electronic devices to be controlled remotely, the transmission comprising the particular address associated with the particular one of the electronic devices and the control command; selectively enabling the .particular one of the electronic devices responsive to the receipt of the particular address and a first control command; and selectively disabling the particular one of the electronic devices responsive to the receipt of the particular address and a second control command.

8. The method of Claim 7 and further comprising the steps of: determining if the data transmissions are intended for the particular electronic device; and generating a switch control signal responsive to the receipt of data transmissions intended for the particular electronic device.

9. The method of Claim 7 and further comprising the step of scanning through a predetermined frequency range until the data transmissions are detected by the controller circuit.

10. The method of Claim 9 and further comprising the step of storing a frequency value associated with a frequency on which the data transmissions are detected.

11. The method of Claim 7 and further comprising the steps of: storing in the controller circuit the particular address associated with the particular electronic device; and searching the data transmission for the presence of the stored address. AMENDED CLAIMS

[received by the International Bureau on 11 May 1992 (11.05.92); original claim 1 amended; new claims 12-14 added; other claims unchanged (3 pages)]

1. A system for controlling remotely electroinc devices, comprising: an accounting system operable to store a plurality of accounts associated with different electronic devices and further operable to identify ones of said accounts which are delinquent; a database system for storing a plurality of addresses, each of said addresses associated with a single electronic device; a selection system coupled to said database system and operable to select a particular address associated with a particular electronic device to be controlled remotely; transmission circuitry for transmitting to a subcarrier paging network said particular address and a control command; and a controller circuit resident in a particular one of the electronic devices to be controlled remotely and operable to receive a frequency modulated transmission from the subcarrier paging network, said associated with said particular one of the electronic devices and said control command, said controller circuit further operable to enable including means for selectively enabling said particular one of the electronic devices responsive to the receipt of said particular address and a first control command and means for selectively disabling, said particular one of the electronic devices responsive to the receipt of said particular address and a second control command.

12. The system of claim 1 wherein said means for selectively enabling said particular electronic device comprises: means for generating a first switch control signal responsive to the receipt of data transmissions intended for enabling said particular electronic device; and a switch coupled to said electronic device and responsive to said first switch control signal for enabling said electronic device; and wherein said means for selectively disabling said particular electronic device comprises: means for generating a second switch control signal responsive to the receipt of data transmissions intended for disabling said particular electronic device; and wherein said switch is responsive to said second switch control signal for disabling said electronic device.

13. A system comprising: a plurality of remote electronic devices; an accounting system operable to store a plurality of accounts associated with different electronic devices and further operable to identify ones of said accounts which are delinquent; a database system for storing a plurality of addresses, each of said addresses associated with a single electronic device; a selection system coupled to said database system and operable to select a particular address associated with a particular electronic device to be controlled remotely; transmission circuitry for transmitting to a subcarrier paging network said particular address and a control command; and a controller circuit resident in a particular one of the electronic devices to be controlled remotely and operable to receive a frequency modulated transmission from the subcarrier paging network, said associated with said particular one of the electronic devices and said control command, said controller circuit including means for selectively enabling said particular one of the electronic devices responsive to the receipt of said particular address and a first control command and means for selectively disabling, said particular one of the electronic devices responsive to the receipt of said particular address and a second control command.

14. The system of claim 13 wherein said means for selectively enabling said particular electronic device comprises: means for generating a first switch control signal responsive to the receipt of data transmissions intended for enabling said particular electronic device; and a switch coupled to said electronic device and responsive to said first switch control signal for enabling said electronic device; and wherein said means for selectively disabling said particular electronic device comprises: means for generating a second switch control signal responsive to the receipt of data transmissions intended for disabling said particular electronic device; and wherein said switch is responsive to said second switch control signal for disabling said electronic device.