WO2003025736A1

WO2003025736A1 - Memory management method for displaying a document on a portable equipment

Info

Publication number: WO2003025736A1
Application number: PCT/FR2002/003157
Authority: WO
Inventors: Pierre Schweitzer
Original assignee: Pierre Schweitzer
Priority date: 2001-09-17
Filing date: 2002-09-16
Publication date: 2003-03-27
Also published as: FR2829845B1; EP1428111A1; FR2829845A1

Abstract

The invention concerns a method for displaying a document on a portable equipment comprising a display screen and an electronic memory, which consists in loading in said memory a digital file, said method comprising: preparing a digital file including a plurality of blocks of constant size, each of the blocks being subdivided into a first sub-block containing a digital image in the form of a frame of NxM points, corresponding to the scanning zone of the display screen, and into a second sub-block with navigation data, comprising inter alia addresses of the beginning of another block; loading said file in the memory of the portable equipment, and transferring the selected block from the memory to the display screen, for displaying the points of the first sub-block in the scanning zone, and the data of the second sub-block in a service zone associated with selection means.

Description

MEMORY MANAGEMENT METHOD FOR VIEWING A DOCUMENT ON A PORTABLE EQUIPMENT

The present invention relates to the field of electronic books, that is to say portable equipment having a display screen and a memory for recording multimedia files, making it possible to restore documents on the screen in the manner of a traditional book. Solutions are known in the state of the art for producing such electronic books.

French patent FR2793052 describes a method for consulting, from a portable reading medium comprising display means, information coming from a computer database or the like, according to which: said information is transferred to said audit nomadic reading medium, this information is recorded at the level of storage means which the latter comprises, in the form of a succession of pages with frozen content, of the facsimile type, at the level of this nomadic reading medium, The display page by page, in the manner of a printing carried out by a printer, of the recorded information, the scrolling, page by page, forward and / or backward, of this information is controlled.

The implementation of this process requires equipment provided with relatively powerful calculation means, which makes its manufacturing cost high, and results in significant electrical consumption, reducing autonomy.

French patent FR2792744 describes an electronic book comprising an electronic central unit which includes a memory and which is connected to a display screen and to a control interface, the memory of the central unit containing at least one document which includes alphanumeric characters and pre-positioned page break marks which are used to set page the document, depending on the type of characters chosen by the user or the characteristics of the screen.

This solution aggravates the drawbacks mentioned above, because the use of documents saved in the form of files according to a standardized coding table (UNICODE, ASCII) viewable with any font implies the use of a central unit equivalent to that of 'a microcomputer.

Saving documents as alphanumeric files or as a "facsimile" is not the only solution. The patent FR2632137 describes for example a transcoding method ensuring the conversion of digital image signals supplied in the form of a succession of bits which translate into a first code the respective states of the pixels of an image supposed to be read by linear scanning.

The bits grouped into bytes of the first code are converted into a compressed code allowing image storage in digital form in a reduced volume of a memory of a micro-editing station. The bytes of the first code are transcoded in the form of modules of four different types which respectively allow a compressive coding of the bytes of the uniform image ranges, of the transition zones, of identical zones of successive lines, as well as of heterogeneous and identical successive bytes. pattern repetition, especially for nuanced areas.

European patent EP338416 describes an infographic system comprising: - a processor which delivers information signals to run display applications and to create display bit configurations, - display control means which respond to said information signals delivered by said processor, to generate virtual addresses and to convert said virtual addresses into physical addresses, - a memory which stores the display bit patterns at physical addresses.

These file processing solutions of the “bitmap” or raster type also require the use of a microprocessor, and therefore have the same drawbacks as those previously stated.

The invention aims to remedy these drawbacks by proposing a method for viewing a document requiring simple equipment, with great autonomy.

To this end, the invention relates, in its most general sense, to a method for viewing a document on portable equipment comprising a display screen and an electronic memory, consisting in loading into said memory a digital file controlling the representation of '' at least part of said document on the screen, characterized in that it comprises: an initial step of preparing the digital file in the form of a file comprising a plurality of blocks of constant size, each of the blocks being subdivided into a first sub-block containing a digital image in the form of a frame of NXM points

(bitmap image), N and M being the number of points respectively per line and per column of the reading area of the display screen, and in a second sub-block comprising navigation data, the navigation data comprising start addresses of another block, a step of loading said file into the memory of the portable equipment, and of transferring the data of a selected block directly from the memory to the display screen , for the display of the points of the first sub-block in the reading area of the screen, and of the data of the second sub-block in a service area associated with selection means activating the addressing of the memory with l one of the addresses appearing in the second sub-block and selected by said selection means.

According to a first advantageous variant, the initial step comprises the construction of an image formed by the area to be displayed and a peripheral area presenting pictograms or texts associated with the addresses recorded in the second sub-block.

According to a second advantageous variant, the initial step comprises the construction of an image of the area to be displayed comprising graphic markers associated with the addresses recorded in the second sub-block. These graphic markers can be constituted by a typographical enrichment of certain passages of text

(bold, underlined, ...) or a color or gloss code for certain graphic areas.

According to a third advantageous variant, the second sub-block comprises addresses of pages predetermined by the titanium of the image forming the first sub-block. Preferably, the data is saved in direct bitmap mode and is not compressed.

According to a variant, the data are recorded in bitmap mode in a compression mode by simple counting of the number of identical bits. Advantageously, the method comprises a step of detecting the activation of the means for selecting and loading the address of the page selected in an address memory of the memory containing said document file.

According to a variant, the block corresponding to the first page is loaded into the memory when the equipment is used.

The invention also relates to equipment for viewing a document comprising a display screen and an electronic memory, characterized in that it comprises a memory, the output of which is directly connected to a display screen or to its driver (driver ) to deliver bitmap type data, the input of which is directly to an addressing circuit controlled by a selection means.

According to a first variant, the selection means are constituted by contactors arranged along the display screen. According to a second variant, the selection means consist of a linear sensor arranged along the display screen.

According to a third variant, the selection means consist of a tactile zone superimposed on the screen.

The invention will be better understood on reading the description which follows, referring to the accompanying drawings in which: FIG. 1 represents a view of equipment according to the invention; - Figure 2 shows a view of the format of the digital file of a document; Figure 3 shows a view of the block diagram of the equipment according to the invention.

Figure 1 shows a schematic view of equipment according to the invention. It is made up of a housing (1) provided on its front face with a screen (2), for example a liquid crystal screen. The screen will preferably be a bistable screen retaining the display state at rest and requiring only a power supply when the state changes.

The screen (2) has a main display area (3) and a secondary display area (4) arranged in the example described laterally, to form a margin in which the pictograms appear whose relative position relative to the contactors (5 to 13) will guide the user in navigating the document. The contactors (5 to 13) are arranged along the secondary display area (4).

The main display area (3) is intended for viewing a page of a document saved in the memory of the equipment.

The secondary display area (4) is intended to display texts or pictograms each associated with the address of another page of the document. Selecting one of the contactors (5 to 13) activates the display of the page corresponding to the address associated with the pictogram displayed next to said contactor.

This series of contactors can be replaced by a touch line at the edge of the screen or by a touch screen area.

A document is loaded into the equipment in the form of a digital file divided into blocks (15 to 18) of constant length.

Each block is composed of a first sub-block (25 to 28) corresponding to the bitmap data (gray or color value of each of the points making up the image, organized according to a standard image interpretation format). The constitution of the data is not subject to compression of the original image, to avoid the use of treatments requiring a processor. The first block contains a "bitmap" image whose format can be:

- The 1-bit format to store images where the dots are either all black or all white. It takes 1 bit per point. This format is well suited for storing images of text or comics in black and white.

- The grayscale format to memorize images where each point can have 256 levels of gray. Each point has a value between 0 (black) and 255 (white). This format allows you to view documents containing figures and B&W photos.

- The Hi-Color format, or 24-bit format, allows you to view 16 million colors. In this format, each quantity of red, its quantity of green and its quantity of blue is memorized for each point, each time using a value between 0 and 255. One byte is therefore required for each color component . To memorize the three color components of a point, you therefore need three bytes, or 24 bits. This format allows viewing of documents containing color photos.

- The 1-bit indexed format, consisting of memorizing which color corresponds to 0 and which color corresponds to I. In this case, the value of the display color will be saved in a part of the file. - The 4-bit indexed format uses a table of 16 colors, numbered from 0 to 15. In this table, each color is described, by its% of red, its% of green, its% of blue. Then, each point of the image is stored under 4 bits. This format is suitable for color documents, with an optimization between the file size and the fidelity of the restitution. The file will include an area in which data relating to the color palette is saved. Optionally, each block includes an area for recording the color palette of the page in question.

Preferably, the images are recorded in the first sub-block according to the BMP type which is an uncompressed format. The points of the image are memorized as they are sequentially. The BMP type can store images in almost all formats; 1-bit, 4-bit,

8-bit, 24-bit, direct or indexed. The block also includes a second sub-block

(35 to 38) in which the addresses of the target page (s) are recorded.

This second sub-block is itself subdivided into a number of zones corresponding to the number of selection means (8 contactors in the example described).

Each of the zones corresponding to an active contactor contains an address of the page to be displayed when the corresponding contactor is activated. These addresses are coded on 2 bytes, which allows access to a maximum of 65536 pages.

During the construction of the bitmap data, the text or the pictogram will be determined, as well as their position on the display screen, so that they appear opposite with the contactor allowing the selection of the page whose address is saved in the corresponding area of the second sub-block.

An association is thus created between the position in the displayed image of the texts or pictograms designating a target page, the position of the buttons or selection means which is predetermined and constant for the equipment intended to exploit the files considered, the number of the zone of the second sub-block and the address of the target page recorded in said zone. The first block (15) could for example contain the contents of a book, in the form of 8 lines. Each line will be positioned so that it is at the height of one of the contactors (5 to 8). The image is therefore constructed taking into account the dimensions of the screen of the equipment and the position of the selection means relative to the screen.

The addresses of the target pages will be recorded in the second sub-block, for example the start address of the second block (16) in the first zone of the sub-block.

(35), the start address of the third block (17) in the second zone of the sub-block (35), etc.

When this page is displayed on the screen (2), the user can navigate in the document by activating the contactor located next to the summary line of interest.

FIG. 3 represents a block diagram of a circuit for controlling an item of equipment according to the invention.

It includes an EPROM type memory (40) for recording a digital file corresponding to a document.

This file can be saved via a serial link from a computer or a terminal, or by a USB type port, or by a radio frequency, infrared link with a charging station or a server equipment, or by a modem for charging via a telecommunications network.

The outputs D0 to D7 of this memory are directly connected to the inputs X0 to X7 of the display. The output of the memory delivers the bitmap data directly used by the display, and the control of the display does not require any prior processing.

The memory is addressed by an electronic circuit controlled by the contactors, and taking into account the content of a table stored in memory, in which the addresses of the target pages associated with said contactors are stored. This table can reside in the original read-only memory, or be transferred to a service area in random access memory when the current page is displayed.

The display of a page on the screen begins with the preloading of a counter of the state machine with the address of the page. This address is sent to the memory, the output of which is connected to the data bus of the screen. Incrementing the counter changes the input address of the memory component which generates the output of the data stream transmitted to the screen. The state machine also generates, in synchronism, the control signals of the screen: validation of reading of the pixels byte by byte, signaling of the end of line of pixels, for example. These parameters, simple, constant and regular, depend on the specifications of the chosen screen. The counter of the state machine is incremented until the end of the first sub-block containing the facsimile of the page to be displayed. Thus, at the end of this display phase, the counter of the state machine points to the start of the second sub-block containing the binding of the page (list of pages linked to the current page via the contactors) .

It is then that the state machine examines the contactors. When a contactor is activated, the state machine receives the number and adds this value to the counter, which then points to the pair of bytes of the binding sub-block containing the address of the page associated with the activated contactor.

The state machine reads this value and writes it directly to the counter itself. This step corresponds to the preload mentioned at the start of the present description. The state machine again performs the steps described above to display the new page.

The organization of data in memory:

Page 1: facsimile (first sub-block). 1st byte of the bitmap to display. 2nd byte of the bitmap to display

. last byte of the bitmap to display

Page 1: binding (second sub-block). address of the page linked to contactor No. l. address of the page linked to contactor n ° 2

. address of the page linked to the last contactor

Page 2: facsimile (first sub-block). 1st byte of the bitmap to display. 2nd byte of the bitmap to display etc. The state machine described above can be produced in different ways: in wired logic with discrete digital components (registers, counters, gates, flip-flops, adders) or by its equivalent in an integrated logic component of EPLD type, or even by a low-end microcontroller (8 bits) preprogrammed (firmware).

In a preferred variant, the contactors (8 here) are more numerous (alignment of pins like a comb), or even as numerous as there are lines of pixels on the screen. In the latter case, the multiple physical contactors can advantageously be replaced by a linear sensor placed along the screen, the analog output of which is digitally converted to send the number of the "theoretical" line of pixels to the state machine. ”Indicated by the user. In this case position of texts, pictograms and typographical enrichment is immaterial since each line visible to the eye can be activated, and associated with a target page address in the second sub-block. In all cases, neither a powerful microprocessor, nor an operating system, nor software application layers is used: the information is stored in memory in its form directly displayable and readable to the human eye, without use of ascii code tables, fonts, layout description formats, etc.

The electronic circuit does not include a microprocessor. It is in the waiting position at rest. When it detects the activation of a contactor, it interrogates the memory containing the table from the second sub-block of the page viewed, and receives in return the start address of the target page. This address is used to display the data corresponding to the selected target page.

Claims

1 - Method for viewing a document on portable equipment comprising a display screen and an electronic memory, consisting in loading into said memory a digital file controlling the representation of at least part of said document on the screen, characterized in that it comprises: an initial step of preparing the digital file in the form of a file comprising a plurality of blocks of constant size, each of the blocks being subdivided into a first sub-block containing a digital image in the form of a frame of NxM points (bitmap image), N and M being the number of points respectively per line and per column of the reading area of the display screen, and in a second sub-block comprising navigation data, the data of navigation comprising start addresses of another block, a step of loading said file into the memory of the portable equipment, and transferring data from a block selected directly from memory to the display screen, for displaying the points of the first sub-block in the screen reading area, and the data of the second sub-block in a service area associated with selection means activating the addressing of the memory with one of the addresses appearing in the second sub-block and selected by said selection means. 2 - Method for viewing a document according to claim 1, characterized in that the initial step comprises the construction of an image formed by the area to be displayed and a peripheral area having pictograms or texts associated with the registered addresses in the second sub-block.

3 - Method for viewing a document according to claim 1, characterized in that, the initial step comprises the construction of an image of the area to be displayed comprising graphic markers associated with the addresses recorded in the second sub-block . These graphic markers can consist of a typographic enrichment of certain passages of text (bold, underlined, ...) or a color or gloss code of certain graphic areas.

4 - Method for viewing a document according to claim 1, characterized in that the second sub-block includes addresses of pages predetermined by the titanium of the image forming the first sub-block.

5 - Method for viewing a document according to claim 1 or 2, characterized in that it comprises a step of detecting the activation of the means for selecting and loading the address of the selected page in a memory addressing the memory containing said document file.

6 - Process for viewing a document according to claim 1 or 2, characterized in that the block corresponding to the first page is loaded into the memory when the equipment is used. 7 - Method for viewing a document according to claim 1 or 2, characterized in that the data in the file are not compressed.

8 - A method for viewing a document according to claim 1 or 2, characterized in that the data is recorded in bitmap mode is recorded in a compression mode by simple counting of the number of identical bits.

9 - Equipment for viewing a document comprising a viewing screen and an electronic memory for implementing the method according to claim 1, characterized in that it comprises a memory, the output of which is directly connected to a screen of display or its driver (driver) to deliver data of the "bitmap" type, the input of which is directly to an addressing circuit controlled by a selection means.

10 - Equipment for viewing a document according to claim 9, characterized in that the selection means are constituted by contactors arranged along the display screen.

11 - Equipment for viewing a document according to claim 9, characterized in that the selection means consist of a tactile zone superimposed on the screen.