USRE40945E1 - Increasing scanning resolution through driving system control - Google Patents
Increasing scanning resolution through driving system control Download PDFInfo
- Publication number
- USRE40945E1 USRE40945E1 US11/357,895 US35789506A USRE40945E US RE40945 E1 USRE40945 E1 US RE40945E1 US 35789506 A US35789506 A US 35789506A US RE40945 E USRE40945 E US RE40945E
- Authority
- US
- United States
- Prior art keywords
- motor
- pulse
- gate clock
- shift gate
- scanner
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 claims abstract description 17
- 238000010586 diagram Methods 0.000 description 6
- 230000003287 optical effect Effects 0.000 description 5
- 230000004048 modification Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
- H04N1/047—Detection, control or error compensation of scanning velocity or position
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
- H04N1/19—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using multi-element arrays
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
- H04N2201/04—Scanning arrangements
- H04N2201/047—Detection, control or error compensation of scanning velocity or position
- H04N2201/04753—Control or error compensation of scanning position or velocity
- H04N2201/04758—Control or error compensation of scanning position or velocity by controlling the position of the scanned image area
- H04N2201/04767—Control or error compensation of scanning position or velocity by controlling the position of the scanned image area by controlling the timing of the signals, e.g. by controlling the frequency o phase of the pixel clock
- H04N2201/04781—Controlling the phase of the signals
- H04N2201/04786—Controlling a start time, e.g. for output of a line of data
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
- H04N2201/04—Scanning arrangements
- H04N2201/047—Detection, control or error compensation of scanning velocity or position
- H04N2201/04753—Control or error compensation of scanning position or velocity
- H04N2201/04789—Control or error compensation of scanning position or velocity in the main-scan direction
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
- H04N2201/04—Scanning arrangements
- H04N2201/047—Detection, control or error compensation of scanning velocity or position
- H04N2201/04753—Control or error compensation of scanning position or velocity
- H04N2201/04791—Control or error compensation of scanning position or velocity in the sub-scan direction
Definitions
- the present invention relates to a method of controlling the scanning resolution of a scanner. More particularly, the present invention relates to a method of increasing the scanning resolution of a scanner through control of its driving system.
- the scanner Due to the many recent advances in computer multimedia technologies, image-processing techniques have gone forward a giant step, leading to some innovative designs for computer peripheral products such as a scanner. In a few years' time, the scanner has developed from a palm-top device capable of scanning only black and white pixels to a full-color high-resolution scanning system. In general, the resolution of a scanner along the horizontal axis depends on the density of its charge-coupled device (CCD) while the resolution of the scanner along the vertical axis depends on the level of precision of its driving system.
- CCD charge-coupled device
- FIG. 1 is a timing diagram showing shift gate clock (SH) pulse and motor pulse (MTP) provided by the driving system of a conventional scanner.
- SH shift gate clock
- MTP motor pulse
- T 1 one SH pulse period is represented by T 1 , which is the time needed to expose a scanner's CCD once.
- T 1 is about 10 ms.
- the motor pulses are signals for controlling the forward rotation of a stepper motor.
- the smaller the stepping angle of the stepper motor the higher the resolution of the scanner is.
- a stepper motor having a small stepping angle a high scanning resolution can be obtained.
- the cost of making a stepper motor with a small stepping angle is relatively high.
- pulsing rate or pulse per second (PPS) of the stepper motor increases, leading to a low torque.
- Low torque increases the probability of stepping loss, thereby resulting in distortion of the scanned image.
- This method relies on displaying an image formed on the CCD in a single exposure twice on a screen in each exposure cycle. Hence, resolution is doubled. However, the image thus obtained is no longer the real optical resolution.
- This method relies on the addition of an external driving circuit so that the original stepper motor is changed to a stepper motor capable of stepping forward in 1 ⁇ 2, 1 ⁇ 4 or 1 ⁇ 8 of a step each time.
- an external driving circuit capable of stepping forward in 1 ⁇ 2, 1 ⁇ 4 or 1 ⁇ 8 of a step each time.
- resolution along the vertical axis is increased.
- the minimum micro-step that can be driven is ultimately limited by the external circuit.
- control becomes very difficult. The outcome is that distortion of the scanned image is unavoidable.
- one object of the present invention is to provide a drive control system capable of increasing the scanning resolution of a scanner.
- the system operates by adjusting the timing relationship between motor pulse and shift gate clock pulse so that a low resolution driving system can achieve a high-resolution scanning.
- a second object of the invention is to provide a driving system capable of increasing scanning resolution without increasing the production cost a scanner.
- the invention provides a method for increasing the scanning resolution of a scanner through control of its driving system.
- Shift gate clock pulses for the charge-coupled device of a scanner are provided so that one clock pulse cycle is a period of exposure of the charge-coupled device.
- Motor pulses are also provided.
- one motor pulse cycle is equivalent to a multiple of shift gate clock pulse cycles.
- a method for increasing the scanning resolution of a scanner through controlling its driving system is provided.
- Motor pulse signals are supplied to the driving motor of the scanner.
- shift gate clock pulses are supplied to the charge-coupled device of the scanner. The motor pulses and the shift gate clock pulses are adjusted so that multiple motor pulses are emitted for every shift gate clock pulse going to the charge-coupled device.
- FIG. 1 is a timing diagram showing the shift gate clock pulse and the motor pulse provided by the driving system of a conventional scanner
- FIG. 2 is a timing diagram showing the shift gate clock pulse and the motor pulse provided by the driving system of a scanner according to this invention.
- FIG. 3 is a schematic diagram of the driving system control according to the present invention.
- the scanning resolution of a scanner is increased by reducing motor pulse cycles per period.
- a plurality of shift gate clock pulses are generated for each forward step taken by the stepper motor.
- FIG. 2 is a timing diagram showing the shift gate clock pulse and the motor pulse provided by the driving system of a scanner according to this invention.
- a single motor pulse is emitted for every two shift gate clock pulses.
- a shift gate clock pulse submitted to the charge-coupled device (CCD) still has a duration T 1 .
- CCD charge-coupled device
- two shift gate clock pulses are generated for each motor pulse, and thus two scanning operations are carried out within each motor pulse cycle.
- near optical resolution of the scanners can be obtained without incurring additional cost for producing the scanner.
- FIG. 3 is a schematic diagram of a scanner showing the driving system control 10 sending the motor pulse (MTP) 50 to the motor 30 and shift gate clock pulse (SH) 40 to the CCD 20 according to this invention.
- MTP motor pulse
- SH shift gate clock pulse
- Tables 1, 2 and 3 below illustrate the improvement in scanning resolution resulting from a modification of the driving system in a conventional scanner.
- the stepper motor in the driving system operates according to a 600 dpi specification. In other words, the stepper motor steps through 600 increments to move forward an inch. To attain a higher resolution of 1200 dpi in the vertical axis, the motor must step forward half a step at a time. However, to attain an even higher resolution such as 2400 dpi is almost impossible unless a driving circuit capable of driving the stepper motor forward through one quarter of the original micro-step is available.
- the stepper motor in the driving system has changed so that the motor now operates according to a 1200 dpi specification.
- the stepper motor steps through 1200 increments to move forward an inch.
- the motor must step forward half a step at a time.
- PPS pulses per second
- the stepper motor in the driving system uses the original design and operates according to a 600 dpi specification. In other words, the stepper motor steps through 600 increments to move forward an inch.
- pulse cycle of the stepper motor is increased so that CCD exposures are conducted twice within each motor pulse cycle.
- pulse cycle of the stepper motor is further increased so that CCD exposures are conducted four times within each motor pulse cycle.
- this invention provides a method of increasing scanning resolution by suitably adjusting the timing relationship between the motor pulse and the shift gate clock pulse that controls the number of CCD exposures.
- a low-resolution driving system is capable of producing a high-resolution scanning.
- a second advantage of this invention is that scanning resolution is improved without incurring additional cost in producing the scanner.
Abstract
Description
-
- Exposure time: 10 ms
- Scanning mode: Grey scale
- Optical resolution: 600 (horizontal axis) dpi
TABLE 1 |
Original design |
Resolution | Number of | Pulse Per Second | |
(Vertical Axis) | Motor Pulse Cycle | Exposures | (PPS) |
75 dpi | 8 | 1 | 800 |
600 dpi | 1 | 1 | 100 |
1200 dpi | 0.5 | 1 | 50 |
2400 dpi | X | X | X |
-
- Exposure time: 10 ms
- Scanning mode: Grey scale
- Optical resolution: 600 (horizontal axis) dpi
TABLE 2 |
Change in the driving system |
Resolution | Number of | Pulse Per Second | |
(Vertical Axis) | Motor Pulse Cycle | Exposures | (PPS) |
75 dpi | 16 | 1 | 1600 |
600 dpi | 2 | 1 | 200 |
1200 dpi | 1 | 1 | 100 |
2400 dpi | 0.5 | 1 | 50 |
-
- Exposure time: 10 ms
- Scanning mode: Grey scale
- Optical resolution: 600 (horizontal axis) dpi
TABLE 3 |
Driving system according to this invention |
Resolution | Number of | Pulse Per Second | |
(Vertical Axis) | Motor Pulse Cycle | Exposures | (PPS) |
75 dpi | 8 | 1 | 800 |
600 dpi | 1 | 1 | 100 |
1200 dpi | 1 | 2 | 50 |
2400 dpi | 1 | 4 | 25 |
Claims (14)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/357,895 USRE40945E1 (en) | 2000-01-15 | 2006-02-17 | Increasing scanning resolution through driving system control |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
TW089100599A TW457808B (en) | 2000-01-15 | 2000-01-15 | Method to increase the scanning resolution by controlling the transmission system |
US09/518,117 US6693730B1 (en) | 2000-01-15 | 2000-03-03 | Increasing scanning resolution through driving system control |
US11/357,895 USRE40945E1 (en) | 2000-01-15 | 2006-02-17 | Increasing scanning resolution through driving system control |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/518,117 Reissue US6693730B1 (en) | 2000-01-15 | 2000-03-03 | Increasing scanning resolution through driving system control |
Publications (1)
Publication Number | Publication Date |
---|---|
USRE40945E1 true USRE40945E1 (en) | 2009-10-27 |
Family
ID=21658484
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/518,117 Ceased US6693730B1 (en) | 2000-01-15 | 2000-03-03 | Increasing scanning resolution through driving system control |
US11/357,895 Expired - Lifetime USRE40945E1 (en) | 2000-01-15 | 2006-02-17 | Increasing scanning resolution through driving system control |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/518,117 Ceased US6693730B1 (en) | 2000-01-15 | 2000-03-03 | Increasing scanning resolution through driving system control |
Country Status (2)
Country | Link |
---|---|
US (2) | US6693730B1 (en) |
TW (1) | TW457808B (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7389002B1 (en) | 2004-03-22 | 2008-06-17 | Knight Andrew F | Method for increasing resolution in a camera |
US10171701B2 (en) * | 2017-04-13 | 2019-01-01 | Microtek International Inc. | Image scanning apparatus |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5150227A (en) * | 1989-06-23 | 1992-09-22 | Kabushiki Kaisha Toshiba | Apparatus for reading character or graphics image on document |
US5381244A (en) * | 1988-11-30 | 1995-01-10 | Fujitsu Limited | Image reading system using an interruption of a pulse train to adjust a scanning period |
US6215513B1 (en) * | 1998-10-16 | 2001-04-10 | Fuji Xerox Co., Ltd. | Pulse generation apparatus and image recording apparatus |
US20010030687A1 (en) * | 1996-12-26 | 2001-10-18 | Kazuyuki Kondo | Image read method for performing image signal processes complying with the color of a reference portion of a recording medium, and image read apparatus adopting the method |
US20020097446A1 (en) * | 2001-01-25 | 2002-07-25 | Umax Data Systems Inc. | Apparatus and method for dark calibration of a linear CMOS sensor |
-
2000
- 2000-01-15 TW TW089100599A patent/TW457808B/en not_active IP Right Cessation
- 2000-03-03 US US09/518,117 patent/US6693730B1/en not_active Ceased
-
2006
- 2006-02-17 US US11/357,895 patent/USRE40945E1/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5381244A (en) * | 1988-11-30 | 1995-01-10 | Fujitsu Limited | Image reading system using an interruption of a pulse train to adjust a scanning period |
US5150227A (en) * | 1989-06-23 | 1992-09-22 | Kabushiki Kaisha Toshiba | Apparatus for reading character or graphics image on document |
US20010030687A1 (en) * | 1996-12-26 | 2001-10-18 | Kazuyuki Kondo | Image read method for performing image signal processes complying with the color of a reference portion of a recording medium, and image read apparatus adopting the method |
US6215513B1 (en) * | 1998-10-16 | 2001-04-10 | Fuji Xerox Co., Ltd. | Pulse generation apparatus and image recording apparatus |
US20020097446A1 (en) * | 2001-01-25 | 2002-07-25 | Umax Data Systems Inc. | Apparatus and method for dark calibration of a linear CMOS sensor |
Also Published As
Publication number | Publication date |
---|---|
TW457808B (en) | 2001-10-01 |
US6693730B1 (en) | 2004-02-17 |
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AS | Assignment |
Owner name: UMAX DATA SYSTEMS, INC., TAIWAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HSU, CHUAN-YU;SHIH, CHEN-HSIANG;REEL/FRAME:017616/0818;SIGNING DATES FROM 20000218 TO 20000221 |
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Owner name: TITUSVILLE CANAVERAL LLC, DELAWARE Free format text: MERGER;ASSIGNOR:TRANSPACIFIC SYSTEMS, LLC;REEL/FRAME:030628/0681 Effective date: 20130213 |
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Owner name: INTELLECTUAL VENTURES I LLC, DELAWARE Free format text: MERGER;ASSIGNOR:TITUSVILLE CANAVERAL LLC;REEL/FRAME:030639/0330 Effective date: 20130214 |
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Owner name: CEDAR LANE TECHNOLOGIES INC., CANADA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTELLECTUAL VENTURES ASSETS LLC;REEL/FRAME:053495/0721 Effective date: 20200428 |