JP5025088B2 - Gradation display device, image reading device, and image forming device - Google Patents

Description

  The present invention relates to an apparatus for gradation-displaying an image on a two-dimensional display surface and an apparatus using the same, and for example, a CRT display, a liquid crystal display, a plasma display, an EL display, an image display of a digital camera, an image display of a mobile phone, an original It can be used for a display of a scanner or a film scanner, a copying machine or a facsimile display.

Japanese Patent No. 2784005 JP 2001-215938 A.

  In an image display device that performs on / off or lighting / non-lighting operations of display pixels arranged in a matrix at binary levels, an area gray scale method and frame rate control (FRC) are used as a method of performing pseudo gray scale display. ) There is a law.

  In the area gradation method, for each pixel included in a unit area (pixel block) of a screen in which display pixels are arranged in a matrix, on / off is controlled based on gradation data, and in that space (block area) Average brightness is determined by the number of ON pixels. That is, the gradation is expressed by the number of ON pixels. The problem with the area gray scale method is that the display resolution decreases in units of blocks.

  In the FRC method, on / off on-duty (on time or on number / predetermined time or predetermined number) is controlled based on gradation data for each pixel included in a target pixel or target region for each image frame displayed one after another. Then, the average brightness in the predetermined time (the number of frames) is determined. That is, the gradation is expressed. As a problem of the FRC method, when a large area is displayed with the same gradation in a pixel displayed in halftone (gradation), flicker called flicker occurs, and the display quality is deteriorated.

  To solve these problems, in the gradation display method described in Patent Document 1, one screen (frame) of the display device is divided into a plurality of sections, each section having N pixels, and the number N of pixels is The area gradation method is controlled so that the number of gradation displayable steps is the same. Furthermore, by sequentially giving a plurality of lighting patterns of different phases prepared corresponding to each gradation over a plurality of frames and performing the control of the FRC method, the lighting patterns in each section are made different for each frame, and the display resolution is lowered. To reduce flicker.

  Further, in the image display device described in Patent Document 2, flicker and moving phenomenon are suppressed with a simple configuration without deterioration in image quality, and four types of area gradation expression patterns (one per gradation) ( Basic patterns) groups GRAPA1 to GRAPA4, a pattern group obtained by rotating each gradation pattern by 90 °, a pattern group rotated by 180 ° and a pattern group rotated by 270 ° are used. That is, three additional rotation pattern groups are added to each basic pattern group, and a total of 16 pattern groups are used to switch the use pattern group which is used by sequentially switching 16 pattern groups in 16 frames. (0018-0021).

  However, in the above prior art, when the number of display gradations is increased, the divided control area (pixel block) is expanded (the number of pixels in the block is increased), the number of patterns in the group (the number of blocks) is increased, and the pattern group The number of frames in which sequential switching is completed increases. In the control for switching the pattern group used in the area gradation method in accordance with the switching of the frame, if the number of used pattern groups to be sequentially switched is increased, the required capacity of the memory holding the pattern group increases. Further, when the number of display gradations increases, there arises a problem that the moving phenomenon is deteriorated, and there is a problem that display quality is deteriorated.

  The present invention has been made in view of the above points, and has as its first object to make it possible to sequentially switch and use various pattern groups without significantly increasing the required memory capacity for holding pattern groups. A second object is to increase the number of display gradations without significantly increasing the number of patterns in a group or the number of frames that are sequentially switched between pattern groups.

(1) A two-dimensional display means (11) having a display surface that expands in the horizontal (x) and vertical (y) directions, and performing display / non-display for each pixel of the ON / OFF signal section on the display surface;
Each of the pixel blocks (4 × 4 pixel matrix) composed of a plurality of pixels in the horizontal and vertical directions represents the distribution of on / off signals instructing the light emission / non-light emission of each pixel and the display gradation of the pixel block. A plurality of light emission pattern data (GPTNA01, GPTNA02, GPTNA03,...) Expressing different gradations are grouped into a group, and a plurality of groups (GPTNA, GPTNB, GPTNC) having different on / off signal distribution patterns for each group. , GPTND) gradation memory (Prg) for storing a basic pattern group (GPTNA);
On the display frame, means for changing the rotational angle instruction signal for each Ri switching picture element blocks water square direction (Xbs) (41,44,69b) and group instruction signal for each Ri switching vertical picture element block Means for changing (Nbg) (42,45,47,51-54);
Means (60, 61, 51-54) for reading light emission pattern data (Dbp) corresponding to the gradation data of the basic pattern group corresponding to the group instruction signal (Nbg) from the gradation memory;
The read light emission pattern data is converted into light emission pattern data (Dbs) having an on / off signal distribution rotated by an angle (0/90/180/270 °) corresponding to the rotation angle instruction signal (Xbs). Rotating means (55,56); and
Means (44, 45, 58, 57, 70) for outputting on / off signals of the light emission pattern data (Dbs) converted by the rotating means (55, 56) to the two-dimensional display means (11);
A gradation display device comprising (FIGS. 9, 21, and 23).

  In order to facilitate understanding, the reference numerals of corresponding elements or equivalent elements or equivalent matters in the parentheses shown in the drawings and described later are added as reference for reference. The same applies to the following.

  According to this, it is possible to sequentially switch and use various pattern groups without significantly increasing the required memory capacity of the gradation memory (Prg).

(2) a two-dimensional display means (11) having a display surface extending in the horizontal (x) and vertical (y) directions, and performing display / non-display in pixel units of the on / off signal section on the display surface;
Each of the pixel blocks (4 × 4 pixel matrix) composed of a plurality of pixels in the horizontal and vertical directions represents the distribution of on / off signals instructing the light emission / non-light emission of each pixel and the display gradation of the pixel block. A plurality of light emission pattern data (GPTNA01, GPTNA02, GPTNA03,...) That express different gradations as one group, and a basic pattern group consisting of a plurality of groups with different on / off signal distribution patterns for each group ( GPTNA) non-volatile memory (2);
Each light emission pattern data read from the non-volatile memory (2) is converted into light emission pattern data (Dbp) of ON / OFF signal distribution rotated by a plurality of different angles (0/90/180/270 °). Rotating means (55, 56) for writing to the key memory (Prg);
On the display frame, means for changing the rotational angle instruction signal for each Ri switching picture element blocks water square direction (Xbs) (41,44,69b) and group instruction signal for each Ri switching vertical picture element block Means for changing (Nbg) (42,45,47,51-54);
Means (60, 61, 51-54) for reading light emission pattern data (Dbs) corresponding to the group instruction signal (Nbg), gradation data and rotation angle instruction signal (Xb) from the gradation memory;
Means (44, 45, 58, 57, 70) for outputting an ON / OFF signal of the read light emission pattern data (Dbs) to the two-dimensional display means (11);
A gradation display device comprising: (FIG. 24).

  According to this, it is possible to sequentially switch and use various pattern groups without significantly increasing the required memory capacity of the nonvolatile memory (2).

( 3 ) The means for changing the rotation angle instruction signal (Xbs) is a horizontal counter comprising a circulation counter that counts the pixel synchronization signal and counts the number of pixels in the horizontal direction in the pixel block to initialize and count the count data. The pixel counter (44) and the number of times of initialization of the horizontal pixel counter (44) are counted, the count value is initialized in synchronization with the switching of the group instruction signal (Nbg), and the horizontal pixel counter (44 A horizontal block counter (69b) that counts the number of times of initialization) and outputs count data (Xbs) as the rotation angle instruction signal (Xbs);
The means (42, 45, 47, 51-54) for changing the group instruction signal (Nbg) counts the horizontal synchronizing signal and counts the number of pixels in the vertical direction in the pixel block. The vertical pixel counter (45), which is a circulating counter for counting, and the number of times of initialization of the vertical pixel counter (45) are counted, and the first set value (4) is counted. a vertical block counter (47) for outputting (yb) as a signal for changing the group instruction signal (Nbg); the gradation display device according to the above ( 1) or (2) (FIGS. 9, 21, and FIG. 23, FIG. 24).

( 4 ) The means (60, 61, 51-54) for reading the light emission pattern data (Dbp / Dbs) from the gradation memory counts the number of times of initialization of the horizontal pixel counter (44), and sets the second set value. When (4) is counted, the count value is initialized and counted again. Based on the count data (Xb) of the horizontal block counter (46) and the count data (yb) of the vertical block counter (47), the first data in the horizontal direction is counted. 2. Encoder (51) for generating a block number (Nb) in a section (4 × 4 block matrix) composed of the number of pixel blocks of two set values (4) and the number of pixel blocks of the first set value (4) in the vertical direction A frame counter (48) for counting the number of frames, an adding means (52) for adding the block number (Nb) and the frame count value of the frame counter (48), and a group indication of the added output data of the adding means Convert to signal (Nbg) Means (53, 54), including; grayscale display device according to (3) (FIGS. 9, 21, 23, 24).

( 5 ) One means (60, 61, 51-54) for reading the light emission pattern data (Dbp / Dbs) from the gradation memory described in ( 4 ) above is used for each display of R, G and B gradation data. A total of three sets; and a means (64, 65) for adding a phase shift value for making the output data different from the other sets to at least two sets of each addition means (52); The color gradation display device described in ( 4 ) above (FIG. 21).

( 6 ) Select the output that uses only the light emission pattern data of the basic pattern group (GPTNA) not using the rotation means (55, 56) and the light emission pattern data rotated by the rotation means (55, 56). The gradation display device according to any one of (1) to ( 5 ), further comprising means (66);

(7 ) The basic pattern group (for example, GPTNA) is a light emission pattern data group representing each gradation (0 to 15) of the narrow gradation range (16) which is half of the wide gradation range (32) represented by the gradation data. (GPTNA0 to GPTNA15);
Each gradation of the wide gradation range (32) includes a plurality of light emission pattern data of the basic pattern group, each corresponding to the group instruction signal (Nbg) , and a plurality of the wide gradations A plurality of light emission pattern data representing gradations in the range (32) are assigned (FIG. 11);
Means (60, 61, 51-54) for reading light emission pattern data (Dbp) from the gradation memory reads light emission pattern data (Dbp / Dbs) corresponding to the group instruction signal (Nbg) ;
The gradation display device according to any one of (1) to (6) above (FIGS. 9, 21, 23, and 24).

  According to this, the number of display gradations can be increased without significantly increasing the number of patterns in the basic pattern group and the number of frames in which the sequential switching of the pattern groups is completed.

( 8 ) One of the even value gradation and the odd value gradation (odd value gradation) in the wide gradation range (32) is addressed to the same gradation of the plurality of basic pattern groups in the low gradation range. The light emission pattern data is assigned, and the other (even value gradation) is assigned light emission pattern data addressed to a different gradation of the plurality of basic pattern groups; the gradation display device according to ( 7 ) above (see FIG. 9, FIG. 21, FIG. 23, FIG. 24).

  According to this, one of the even value gradation and the odd value gradation (odd value gradation) in the wide gradation range (32) is addressed to the same gradation of the plurality of basic pattern groups in the low gradation range. The basic gradation display using the light emission pattern data is performed, while the other (even value gradation) is the quasi gradation display in which the light emission pattern data addressed to different gradations are arranged in a plane. It is possible to increase the number of display gradations without significantly increasing the number of patterns in the basic pattern group and the number of frames in which the sequential switching of pattern groups makes a round.

( 9 ) The means (60, 61, 51-54) for reading the light emission pattern data (Dbp / Dbp) from the gradation memory has a narrower range (16) than the wide range (32) gradations represented by the gradation data. (1) to ( 8 ), including means (62) for converting the narrow-range gradation data representing the gray scales of the above into gradation data representing the wide range (32) gradations. The gradation display device described (FIGS. 9, 21, 23, and 24).

( 10 ) an imaging device (100) for converting an optical image into image data representing it; and
Optical image reading comprising the gradation display device (10) according to any one of (1) to ( 9 ), wherein the image data generated by the imaging device is displayed on the two-dimensional display means (11). Device (Figure 1).

( 11 ) A document scanner (100, 120) that reads an image of a document and generates image data representing the image; and
The gradation display device according to any one of (1) to ( 9 ), wherein image data generated by the document scanner is displayed on the two-dimensional display means (11);
A document reading device (FIG. 1).

( 12 ) The document reading device according to ( 11 ) above;
A printer (200) for forming an image represented by the image data on paper; and
An image forming apparatus (FIG. 1) comprising image data processing means (302) for converting image data generated by the document reading apparatus into image data suitable for image forming characteristics of the printer.

( 13 ) The gradation display device (10) is in an operation terminal (10) that gives a user instruction to the image forming device; the image forming device according to ( 12 ) above.

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

  FIG. 1 shows an external appearance of a full-color digital multi-function copier MF1 including an operation board 10 equipped with a gradation display device (FIGS. 6, 8, and 9) according to the first embodiment of the present invention. The full-color copying machine MF1 is roughly constituted by units of an automatic document feeder (ADF) 120, an operation board 10, a color scanner 100, and a color printer 200. The operation board 10 and the color scanner 100 with the ADF 120 are units that can be separated from the printer 200. The color scanner 100 has a control board having a power device driver, sensor input, and controller, and an engine controller ( CPU 301: Directly or indirectly communicates with FIG. 4) to read the document image under timing control.

  A controller board (400: FIG. 4) to which a scanner 100, a printer 200 and an engine (300: FIG. 4) including an image input / output device (302: FIG. 4) are connected is connected to a LAN (Local Area Network) connected to a personal computer PC. Is connected, and a facsimile control unit (FCU 417: FIG. 4) is connected to a switch PBX connected to a telephone line PN (facsimile communication line).

  FIG. 2 shows a document image reading mechanism of the scanner 100 of the multifunction copying machine MF1 and the ADF 120 attached thereto. The original placed on the contact glass 101 of the scanner 100 is illuminated by the illumination lamp 102, and the reflected light (image light) of the original is reflected by the first mirror 103 in parallel with the sub-scanning direction y. The illumination lamp 102 and the first mirror 103 are mounted on a first carriage (not shown) that is driven at a constant speed in the sub-scanning direction y. Second and third mirrors 104 and 105 are mounted on a second carriage (not shown) that is driven in the same direction as the first carriage, and the image light reflected by the first mirror 103. Is reflected downward (z) by the second mirror 104, reflected in the sub-scanning direction y by the third mirror 105, converged by the lens 106, irradiated to the CCD 107, and converted into an electrical signal. That is, it is converted into RGB color image signals.

  The first and second carriages are driven forward (original scanning) and backward (return) in the y direction using the traveling body motor 108 as a drive source. As described above, the scanner 100 is a flatbed reading original scanner that scans the original on the contact glass 101 with the lamp 102 and the mirror 103 and projects the original image on the CCD 107, but the first carriage is in the home position (standby position). It is also possible to stop at the HP and perform sheet-through reading.

  In order to perform sheet-through reading, an automatic document feeder (ADF) 120 is mounted on the scanner 100, and the sheet is placed at the reading visual field position of the first mirror 103 when the first carriage is stopped at the home position HP. There is a glass 132 that is a through reading window, and a transport drum (platen) 125 of the ADF 120 faces the glass 132.

  Documents stacked on the document tray 121 of the ADF 120 are detected by the filler sensor 130. The document size is determined based on whether the switch group 131 that detects the set position of the side plate that forces the document to a predetermined posture is on or off. At the time of sheet-through reading, the uppermost one of the documents stacked on the document tray 121 of the ADF 120 is sent to the registration roller 125 by the pickup roller 122 and the feeding rollers 123 and 124, and sent from the registration roller 125 to the window glass 132. At this time, the image on the original is reflected by the second mirror 104 and projected onto the CCD 107 by the first mirror 103 at the home position HP, and the CCD 107 photoelectrically converts the projected image to generate an image signal. That is, RGB color image signals are generated.

  In this embodiment, the home position HP is a sheet-through reading position of the image reading optical system, and is a first carriage driving start point (= return end point) of flat bed reading. In the case of flat bed reading, the first carriage is driven from the home position HP, and reading of a document image is started from a position advanced by a distance of A + B from HP (right end of the scale plate scp: reading start point). That is, the image signal generated by the CCD 107 is validated. Between the home position HP and the reading start point, there are a base point sensor 109 for detecting the first carriage and a reference white plate rwp. The reference white plate rwp is in close contact with the upper surface of the left end portion of the contact glass 101. Although the reference white plate rwp has read a document having a uniform density due to variations in individual light emission intensities of the illumination lamp 102, variations in the main scanning direction x, sensitivity unevenness for each pixel of the CCD 107, and the like. It is prepared for correcting the phenomenon in which read data varies (shading correction). It is also used for image signal amplification gain adjustment (AGC).

  At the time of flat bed reading, the sub-scan driving of the first carriage and the tracking of the sub-scan position are started from the home position HP. When the reference white plate rwp is in the reading field of the first carriage, the image signal of the CCD 107 (image data obtained by digital conversion) is read into the image signal processing circuit 111 (FIG. 4). When the first carriage crosses the base point sensor 109, the first carriage is started and the scanning speed converges to the set value. When the sub-scanning position reaches the reading start end (A + B: right side of the right end of the scale plate scp), the image signal valid signal (frame synchronization signal: FGATE) is switched to a significant level. In the flat bed reading, the first carriage is sub-scanned to the front end (right end) of the document on the contact glass 101, and when it is turned back to return driving, it temporarily stops at the home position HP. The sensor 109 detects the first carriage, and the sub-scanning position is initialized to the base point position data (set value) at the time of detection. The first carriage is temporarily stopped at the home position HP and then driven to the document size detection position (A + B + C), where it waits.

  The base body 135 of the ADF 120 is hinge-coupled (hinge-connected) to the base body of the scanner 100 on the back side (the back side in FIG. 2), and has a handle 136 on the front side of the base body 135 (the front side in FIG. 2). By raising the substrate 135, the ADF 120 can be raised (opened). On the back side of the base body 135 of the ADF 120, there is a pressure plate switch that detects opening and closing of the ADF 120. In this embodiment, when the ADF 120 is raised from the prone posture shown in FIG. 1 to the standing posture, the lower surface of the pressure plate (document pressing plate) 137 is set to an angle of about 20 ° with respect to the document placement surface of the contact glass 101. When the pressure plate switch exceeds the pressure plate switch, the pressure plate switch is switched from OFF indicating pressure plate close to ON indicating pressure plate open, and in the process of falling from the standing posture to the flat posture, the lower surface of the pressure plate 137 is placed on the document placement surface of the contact glass 101. On the other hand, when the angle is equal to or smaller than the set angle, the pressure plate switch is switched from ON indicating pressure plate opening to OFF indicating pressure plate closing.

  In this way, the switching angle of the pressure plate switch open / close detection is set to a wide angle of about 20 ° because the original size detection position (FIG. 2) is set in advance when the angle is smaller than the set angle. The illumination lamp 102 on the positioned first carriage is turned on to illuminate the original on the contact glass 101, the original image is projected onto the CCD 107, and the boundary between the original and the background based on the image signal of the CCD 107, that is, the original side This is to detect the edge (the width of the document in the main scanning direction x). When the ADF 120 is tilted by about 10 ° or more, the light from the illumination lamp 102 is reflected by the original on the contact glass 101 and reaches the CCD 107 and is detected brightly by the CCD 107, but the light outside the original is detected by the pressure plate 137. Although reflected from the lower surface, since the lower surface is inclined, it almost goes outside the optical field of view of the CCD 107, so that the outside of the original is detected darkly by the CCD 107. A digital processing circuit (AFE) 111 (FIG. 4), which will be described later, detects the size of the document on the contact glass 101 in accordance with such a difference in brightness.

In this embodiment, the following modes of document image reading can be performed:
1. Manual Document Reading The user raises the ADF 120 and places the document on the contact glass 101. The user scans the document with the pressure plate 137 by tilting the ADF 120, and performs the above-described flat bed type document scanning (flat bed reading). When the first carriage passes directly below the reference white plate rwp, the shading correction data is generated based on the read image data of the reference white plate rwp, and the shading correction data in the memory is updated to the one obtained this time. When the flatbed reading is finished, the user raises the ADF 120 and takes out the document. When the user sets a document on the contact glass 101 and closes the ADF 120, the AFE 111 (FIG. 4) detects the size of the document on the contact glass 101.
2. Sheet-through reading The document on the document tray 121 is transferred by the ADF 120 and the above-described sheet-through reading is performed. When a single document is fed from the tray 121, the first carriage is driven to the position of the reference white plate rwp and returned to the home position HP. When the first carriage is directly below the reference white plate rwp, the read image data of the reference white plate rwp is displayed. Based on this, the shading correction data is generated, and the shading correction data in the memory is updated to the one obtained this time. This reading is performed for each of the documents on the document tray 121.

  FIG. 3 shows the mechanism of the color printer 100 of the multi-function copying machine MF1. The color printer 200 of this embodiment is a laser printer. The laser printer 200 includes four toner image forming units a to d for forming images of each color of magenta (M), cyan (C), yellow (Y), and black (black: K). They are arranged in this order along the moving direction of the transfer belt 208 (from left to right y in the figure). That is, it is a four-drum type (tandem type) full-color image forming apparatus.

  A neutralizing device, a cleaning device, a charging device 202 and a developing device 204 are arranged on the outer periphery of the photosensitive member 201 that is rotatably supported and rotates in the direction of the arrow. A space for storing optical information emitted from the exposure device 203 is secured between the charging device 202 and the developing device 204. There are four (a, b, c, d) photoconductors 201, but the image forming component configuration provided around each is the same. The color of the color material (toner) handled by the developing device 204 is different. A part of each photoconductor 201 (four) is in contact with the first transfer belt 208. A belt-like photoreceptor can also be employed.

  The first transfer belt 208 is supported and stretched between a rotating support roller and a driving roller so as to be movable in the direction of the arrow. The first transfer roller is located near the photoconductor 201 on the back side (inside the loop). Has been deployed. A cleaning device for the first transfer belt is disposed outside the belt loop. After the toner image is transferred from the first transfer belt 208 to the transfer paper (paper) or the second transfer belt, unnecessary toner remaining on the surface is wiped off. The exposure device 203 uses a known laser method to irradiate the uniformly charged surface of the photosensitive member with optical information corresponding to full-color image formation as a latent image. An exposure apparatus comprising an LED array and an image forming means can also be employed.

  In FIG. 3, a second transfer belt 215 is provided on the right side of the first transfer belt 208. The first transfer belt 208 and the second transfer belt 215 come into contact with each other to form a predetermined transfer nip. The second transfer belt 215 is supported and stretched between a support roller and a drive roller so as to be movable in the direction of the arrow, and a second transfer means is provided on the back side (inside the loop). A cleaning device, a charger, and the like for the second transfer belt are provided outside the belt loop. After the toner is transferred to the paper, the cleaning device wipes off the remaining unnecessary toner. The transfer paper (paper) is stored in the paper feed cassettes 209 and 210 in the lower part of the figure, and the uppermost paper is conveyed one by one by the paper feed roller to the registration roller 233 through a plurality of paper guides. Above the second transfer belt 215, a fixing device 214, a paper discharge guide 224, a paper discharge roller 225, and a paper discharge stack 226 are arranged. A storage unit 227 for storing replenishment toner is provided above the first transfer belt 208 and below the paper discharge stack 226. The toner has four colors, magenta, cyan, yellow, and black, and is in the form of a cartridge. The developing device 204 of the corresponding color is appropriately supplied by a powder pump or the like.

  Here, the operation of each unit during duplex printing will be described. First, image formation by the photoconductor 201 is performed. That is, by the operation of the exposure device 203, light from an LD light source (not shown) passes through an optical component (not shown), and among the photoconductors 201 uniformly charged by the charging device 202, the photoconductor of the image forming unit a. Then, a latent image corresponding to the writing information (information corresponding to the color) is formed. The latent image on the photoconductor 201 is developed by the developing device 204, and a visible image with toner is formed and held on the surface of the photoconductor 201. This toner image is transferred onto the surface of the first transfer belt 208 that moves in synchronization with the photoreceptor 201 by the first transfer means. The surface of the photoconductor 201 is cleaned by the cleaning device with the remaining toner, and is neutralized by the static eliminator to prepare for the next image forming cycle.

  The first transfer belt 208 carries the toner image transferred on the surface and moves in the direction of the arrow. A latent image corresponding to another color is written on the photoconductor 201 of the image forming unit b, and developed with a toner of the corresponding color to become a visible image. This image is overlaid on the visible image of the previous color already on the first transfer belt 208, and finally four colors are overlaid. In some cases, only monochrome black is formed. At this time, the second transfer belt 215 is moved in the direction of the arrow in synchronization, and the image formed on the surface of the first transfer belt 208 is transferred to the surface of the second transfer belt 215 by the action of the second transfer means 117. The The first and second transfer belts 208 and 215 are moved while the images are formed on the respective photosensitive members 201 of the four image forming units a to d in the so-called tandem format. Can be shortened. When the first transfer belt 208 moves to a predetermined position, a toner image to be created on another side of the paper is formed again by the photoconductor 201 in the process described above, and paper feeding is started. The uppermost sheet in the sheet feeding cassette 121 or 122 is pulled out and conveyed to the registration roller 233. The toner image on the surface of the first transfer belt 208 is transferred by the second transfer unit 117 to one side of the sheet fed between the first transfer belt 208 and the second transfer belt 215 via the registration roller 233. Further, the recording medium is conveyed upward, and the toner image on the surface of the second transfer belt 215 is transferred to the other surface of the sheet by the charger. At the time of transfer, the sheet is conveyed at a timing so that the position of the image is normal.

  The paper on which the toner images are transferred on both sides in the above steps is sent to the fixing device 214, and the toner images (both sides) on the paper are melted and fixed at one time. Are discharged to the paper discharge stack 226.

  As shown in FIG. 3, when the paper discharge units 224 to 226 are configured, the side (page) of the double-sided image that is later transferred to the paper, that is, the surface that is directly transferred from the first transfer belt 208 to the paper is the lower surface. Since the image is placed on the paper discharge stack 226, an image of the second page is created first and the toner image is held on the second transfer belt 215 in order to align the pages. The image is directly transferred from the first transfer belt 208 to the sheet. The image directly transferred from the first transfer belt 208 to the paper is a normal image on the surface of the photoconductor, and the toner image transferred from the second transfer belt 215 to the paper is a reverse image (mirror image) on the surface of the photoconductor. It is exposed as follows. Such image forming order for page alignment and image processing for switching between normal and reverse images (mirror images) are also performed by image data read / write control to the memory 406 by the document storage control 403 (FIG. 4). After transfer from the second transfer belt 215 to the paper, a cleaning device including a brush roller, a collection roller, a blade, and the like removes unnecessary toner and paper dust remaining on the second transfer belt 215.

  In FIG. 3, the brush roller of the cleaning device for the second transfer belt 215 is in a state separated from the surface of the second transfer belt 215. The structure can swing around a fulcrum and can be brought into contact with and separated from the surface of the second transfer belt 215. Before the transfer onto the paper, the second transfer belt 215 is separated when carrying a toner image, and when cleaning is required, it is swung in the counterclockwise direction in FIG. The removed unnecessary toner is collected in a toner storage unit. The image forming process in the duplex printing mode in which the “duplex transfer mode” is set has been described above. In the case of duplex printing, printing is always performed by this image forming process.

  In the case of single-sided printing, there are two types of "single-sided transfer mode by the second transfer belt 215" and "single-sided transfer mode by the first transfer belt 208", and the single-sided transfer mode using the former second transfer belt 215 is set. In this case, a visible image formed in three colors, four colors, or monochromatic black on the first transfer belt 208 is transferred to the second transfer belt 215 and transferred to one side of the paper. There is no image transfer on the other side of the paper. In this case, there is a print screen on the upper surface of the printed paper discharged to the paper discharge stack 226.

  When the single-sided transfer mode using the latter first transfer belt 208 is set, a visible image formed in three colors, four colors, or single color black is transferred to the second transfer belt 215 on the first transfer belt 208. Instead, it is transferred to one side of the paper. There is no image transfer on the other side of the paper. In this case, there is a print screen on the lower surface of the printed paper discharged to the paper discharge stack 226.

  FIG. 4 shows the configuration of the image processing system of the multifunction copying machine MF1 shown in FIG. The multi-function copier MF1 includes an engine 300 that performs document image reading and color printing, a controller board 400, and an operation board 10. The engine 300 includes a CPU 301 that controls image reading and printing processes, the above-described color scanner 100, the above-described printer 200, and an image input / output processing 302 that includes an ASIC (Application Specific IC).

  The reading unit 110 of the scanner 100 includes a CPU, a ROM, and a RAM, and the CPU 100 controls the entire scanner 100 by writing a program stored in the ROM and executing the program. Further, it is connected to the process control CPU 301 via a communication line, and performs an operation instructed by transmission / reception of commands and data. The CPU in the reading unit 110 performs detection and ON / OFF control of a filler sensor (document detection sensor), a base point sensor, a pressure plate switch, a cooling fan, and the like. In the reading unit 110, a scanner motor driver is driven by a PWM output from the CPU, generates an excitation pulse sequence, and drives a pulse motor for scanning a document.

  The document image is illuminated by the light output of the halogen lamp 102 (FIG. 2) energized by the lamp regulator, and the reflected light of the document, that is, the optical signal, passes through the plurality of mirrors 103 to 105 and the lens 106 to read R, G, and B. The image is formed on a CCD 107 including three line sensors. The 3-line CCD 107 outputs an analog image signal of each RGB pixel to the AFE 111. The AFE 111 is an image signal processing unit that amplifies an image signal, digitally converts it into image data, and performs shading correction.

  The controller board 400 includes a CPU 402, a document storage control 403 constituted by an ASIC, a hard disk device (hereinafter referred to as HDD) 401, a local memory (MEM-C) 406, a system memory (MEM-P) 409, North Bridge (hereinafter referred to as NB) 408, South Bridge (hereinafter referred to as SB) 415, NIC 410 (Network Interface Card), USB device 411, IEEE 1394 device 412, Centronics device 413 and others. The operation board 10 is connected to the document accumulation control 403 of the controller board 400. A facsimile control unit (FCU) 417 is also connected to the document storage control 403 by a PCI bus.

  The CPU 402 can transmit / receive document information to / from a personal computer PC connected to the LAN via the NIC 410 or another personal computer PC via the Internet. In addition, it is possible to communicate with a personal computer, a printer, a digital camera, or the like using the USB 411, IEEE 1394 412, and Centronics 413.

  The SB 415, the NIC 410, the USB device 411, the IEEE 1394 device 412, the Centronics device 413, and the MLB 414 are connected to the NB 408 via a PCI bus. As described above, the MLB 414 is a board connected to the engine 300 via the PCI bus. The MLB 414 converts the document data input from the outside into image data (image data), and outputs the converted image data to the engine 300.

  The local memory 406, HDD 401, and the like are connected to the document storage control 403 of the controller board 400, and the CPU 402 and the document storage control 403 are connected via the NB 408 of the CPU chipset. The document accumulation control 403 and the NB 408 are connected via an AGP (Accelerated Graphics Port).

  The CPU 402 performs overall control of the multifunction function copying machine MF1. The NB 408 is a bridge for connecting the CPU 402, system memory 409, SB 415, and document storage control 403. A system memory 409 is a memory used as a drawing memory or the like of the multifunction copying machine MF1. The SB 415 is a bridge for connecting the NB 408 to the PCI bus and peripheral devices. The SB 415 is connected to a card IF 418 for reading and writing an external ROM and an SD memory card (hereinafter referred to as an SD card). The card IF 418 is connected to an SD card read / write device (card reader), and can read data from an SD card attached to the card reader, and can write data to the SD card.

  The local memory 406 is a memory used as a copy image buffer and a code buffer. The HDD 401 is a memory for storing image data, document data, programs, font data, forms, LUT (Look Up Table), and the like. The operation board 10 is an operation unit that receives an input operation from the user and performs display for the user.

  FIG. 4 shows a flow of image data exchanged between the scanner 100 and the printer 200 and the image input / output processing 302. The image input / output processing 302 includes scanner image processing 303 that performs reading γ correction, MTF correction, and the like for each of R, G, and B image data generated when the color original scanner 100 reads an original image. Printer image processing 304 that converts R, G, B image data into c, m, y, k recording color data (print data) that matches the image expression characteristics of the C, M, Y, K color writing of the printer 200. In addition, there is an image processing I / F (Interface circuit) 305 that outputs document read image data RGB to the document storage control 403 and supplies the image data RGB output from the document storage control 403 to the printer image processing 304.

  In the case of monochrome copying, the G image data is output from the scanner image processing 303 to the image processing I / F 305, the image processing I / F 305 outputs the G image data to the printer image processing 304, and the printer image processing 304 is the G image data. Is converted into k recording color data, and if necessary, scaling, image processing, printer γ conversion and gradation processing are performed, and the result is output to the C writing unit 212 of the printer 200. The writing unit 212 modulates or turns on / off the current supplied to the laser light emitting diode of the optical scanning unit 203 (FIG. 3) according to the k recording color data output from the image processing 304.

  For color copying, RGB image data output by the scanner image processing 303 is temporarily stored in the local memory 406 or the HDD 401 or registered in the HDD 401 and read out via the image processing I / F 305 and the image storage control 403. Used for copying or printing, or sent to the outside.

  When printing registered image data by the printer 200 or image data received from the outside, the image data is given to the printer image processing 304 via the image accumulation control 403 and the image processing I / F 305. The printer image processing 304 converts the image data into cmyk recording color data, performs scaling, image processing, printer γ conversion and gradation processing as necessary, and outputs the result to the writing unit 212.

  FIG. 5 shows an overview of the functions of the scanner image processing 303 and the printer image processing 304 shown in FIG. The RGB image data output from the AFE 111 of the color original scanner 100 is subjected to a scanner γ correction 306, and according to the image area detection result of the image area separation 310, edge enhancement processing is applied to the edge area of the image, and the density is smoothed. A filter process 307 for applying a smoothing process is added to the changing halftone area.

  When the “black (BK)” button (FIG. 6) is an instruction for black-and-white reading or black-and-white copying in a designated state (filled state), only the G image data to which edge enhancement processing or smoothing processing is applied in the filter processing 307 is performed. It is written in the page memory 308. When the “full color” button is in the designated state, RGB image data obtained by performing edge enhancement processing or smoothing processing in the filter processing 307 is accumulated in the memory 406 (FIG. 4). When the “automatic color selection” button is in a designated state, and “black (BK)”, “full color”, “automatic color selection”, “blue (C)”, “red (R)” and “yellow ( When none of the “Y” ”buttons are read and the print color cannot be specified, the RGB image data processed by the filter processing 307 is accumulated in the memory 406 and the G image data is written in the page memory 308. It is.

  The data selector 309 selectively outputs one of the G image data in the page memory 308 and the RGB image data subjected to the filter processing 307 as read image data. The image data output from the page memory 308 of the scanner image processing 303 to the image processing I / F 305 is thereafter handled as Bk image data for monochrome reading.

  The image area separation 310 performs edge enhancement processing 311 on the G image data that has been subjected to the scanner γ correction 306 for correcting the reading distortion. The edge enhancement processing 311 sequentially sets each pixel to which each image data of the G image data sequence is addressed as a target pixel, and converts each pixel of the pixel matrix into each image data of, for example, a 3 × 3 pixel matrix centered on the target pixel. This is converted into the sum of products multiplied by the edge enhancement coefficient addressed, and this is used as the edge detection value of the pixel of interest. The edge detection value represents the sharpness of the edge.

  The edge detection value is converted into binary data (H: image edge candidate / L: non-edge) indicating whether or not it is an image edge candidate by binarization 314, and the pixel of interest is detected at the edge position (edge) by pattern matching 315. Pixel) or not. That is, it is determined whether the region of the target pixel is a binary image such as a character or a line drawing or a halftone image such as a photograph. The pattern matching 315 is performed when the distribution of the area (3 × 3 pixel matrix) centered on the target pixel of the binary data indicating whether or not the edge pixel is output from the binarization 314 matches a predetermined edge pattern. The pixel of interest at that time is determined as a pixel in the image edge region (character region).

  The determination result of pattern matching 315 (image edge (character) / non-edge (photo), that is, character / photo) is given to the filter processing 307, and the filter processing 307 adds the determination result to the image data corrected by the scanner γ. ”Region is subjected to edge enhancement processing, and“ non-edge ”region is subjected to smoothing processing in which the density changes smoothly.

  An ACS (Auto Color Select) 317 detects whether the document read image data represents a monochrome image or a color image. An ACS 317 monochrome / color detection signal and an image edge / non-edge detection signal representing the determination result (edge (character) / non-edge (photo)) of the image area separation 310 are provided to the page determination 318. The page determination 318 integrates the color of the monochrome / color detection signal and the number of detected pixels (number of image data) and the image edge of the image edge / non-edge detection signal and the number of detected pixels during reading of one page of the document. When the reading of one page of the document is completed, it is determined whether each integrated value is greater than or equal to each set value. If the number of pixels detected as color is greater than or equal to the set value, the document image is “color” and less than the set value If the number of pixels detected as an image edge is greater than or equal to the set value, it is determined to be a binary image such as a character or line drawing (this is simply referred to as “character”) and is less than the set value. And a non-edge image (this is simply referred to as “photo”). The CPU 301 refers to the determination result (black / white / color & text / photo) of the page determination 318 when reading of one page of the original is completed.

  The color correction 331 of the printer image processing 304 converts the RGB image data into ymc (recording color) image data and outputs the converted image data to the main scanning magnification 332. The main scanning zooming 332 performs zooming as necessary, and then performs printer gamma correction 333 to match the image forming characteristics of the printer 200, and the gradation processing 334 performs recording / non-printing matrix distribution in units of pixels. Then, the image data is converted to image data representing the density gradation and then output to the printer 200. When the image data to be given is only G (Bk) (monochrome), the image data is given not to the color correction 331 but to the main scanning magnification 332. That is, the color correction process is not applied.

  As shown in FIG. 6, in addition to the liquid crystal touch panel 11, the operation board 10 equipped with the gradation display device of the first embodiment of the present invention includes a numeric keypad 15, a clear / stop key 16, a start key 17, an initial setting. There are a key 18, a mode switching key 19, a test print key 20, and a power key 21. Although not shown, on the left side of the liquid crystal touch panel 11 which is a two-dimensional display means, an alphabet keyboard with hiragana added for input, setting and abbreviated registration for URL, mail text, file name, folder name, etc. There is.

  The power key 21 is an operation key for instructing switching from the energy saving mode (the sleep mode or the low power mode) to the standby mode in which image printing is possible and vice versa. If the power key 21 is pressed once when the energy saving mode is set, the energy saving mode is switched to the standby mode. When the power key 21 is pressed once in the standby mode, the standby mode is switched to the sleep mode. The test print key 20 is a key for printing only one copy regardless of the set number of print copies and confirming the print result.

  By pressing the initial setting key 18, the initial state of the machine can be arbitrarily customized. It is possible to arbitrarily set the state set when the transition time to the energy saving mode is set, the paper size stored in the machine is set, or the copy function reset key is pressed. When the initial setting key 18 is operated, an "initial value setting" function for setting various initial values, an "ID setting" function, a "copyright registration / setting" function, an "usage record output" function, etc. A selection button to specify is displayed.

  On the liquid crystal touch panel 11, various function keys and messages indicating the operation states of the engine 300 and the controller board 400 are displayed. The LCD touch panel 11 is used for selecting and executing the “copy” function, “scanner” function, “print” function, “facsimile” function, “store” function, “edit” function, “register” function, and other functions. A function selection key 14 representing is displayed. An input / output screen determined for the function designated by the function selection key 14 is displayed. For example, when the “copy” function is designated, the function keys, the number of copies, and the state of the image forming apparatus are shown as shown in FIG. Messages 12 and 13 are displayed. Among the function keys 12, print color designation keys “black (BK)”, “full color”, “automatic color selection”, “blue (C)”, “red (M)” and “yellow (Y)” designation There is a key. When the operator touches a key displayed on the liquid crystal touch panel 11, the operation board 10 reads it as an operator input, and highlights the key indicating the selected function in gray indicating that it is being designated. Further, when it is necessary to specify the details of a function (for example, the type of page printing), a detailed function setting screen is popped up by touching a key. Thus, since the liquid crystal touch panel 11 uses a dot display, it is possible to graphically perform an optimal display at that time.

  FIG. 7A shows an image reading input screen displayed on the liquid crystal touch panel 11 when the user touches the “read” key in the function selection key 14, and FIG. Indicates a display on the liquid crystal touch panel 11 of an image read by the document scanner 100. When the user makes a required input on the input screen shown in FIG. 7A and double-clicks the “Get” button, the document scanner 100 reads the image, and the read image is shown in FIG. ) And the image data are stored in the memory 406 or the HDD 401 as shown in FIG. The input screen shown in FIG. 7A includes a region 31 with a scale for region designation, and a rectangular dotted line block 32 representing the designated region is displayed in the region. A small square operation location mark 33 is displayed at each of the four corners of the dotted line block 32, and by specifying this and moving it up, down, left and right, the shape of the dotted line block 32 changes while maintaining the rectangle. That is, the designated area can be adjusted. The x (horizontal direction in the figure) and y (vertical direction) coordinate values of the diagonal corner of the dotted block 32 when a document image capture instruction (double click of the “capture” button) is given are read as area designation data.

  The five buttons in the “captured image” column on the input screen shown in FIG. 7A specify image processing characteristics in the scanner image processing 303 and represent the image type of the document to be read. By one-clicking the display button, image data processing that optimally represents the document image is designated. The check “Use ADF” in the column of the reading mode means specification of sheet-through reading using ADF, and if there is no check, it is reading specification of the original placement method. In the case of “use ADF”, all the originals placed on the ADF original table are automatically and sequentially read. When scanning with the flatbed method is selected, the scanning operation will be completed when a single document is scanned if “Multiple scanning” is not checked. However, if “Multiple scanning” is checked, a single document will be scanned. An instruction input screen as to whether to end the reading operation is displayed in a pop-up, and when the user instructs to end the reading operation, the reading operation is ended there. If the “take” button is clicked without instructing the end, one more original is read and an instruction input screen for popping up is displayed in a pop-up.

  FIG. 8 shows a circuit block of the operation board 10. The main body of the electric control system of the operation board 10 communicates with the CPU 402 of the controller board 400, reads the input of the operation board 10, and controls the display on the operation board 10, and stores the control program of the CPU 1. ROM 2, RAM for temporarily storing data during control, VRAM 7 for storing drawing data of the liquid crystal touch panel 11, drawing timing control of the liquid crystal touch panel 11 connected to the VRAM 7, touch input detection, etc. There are a liquid crystal display controller (LCDC) 6, a clock IC 5 for generating time data, and the like. A liquid crystal touch panel 11 having a CFL light source as a backlight 9 is connected to the LCDC 6. The CPU 1 is further connected to an inverter 8 that drives the CFL backlight 9, a key matrix of operation key groups 15 to 21, an LED matrix of display LEDs, an LED driver that drives these LEDs, and the like. Further, a nonvolatile RAM (NVRAM) 4 for storing an image processing mode is connected to the data bus to which the CPU 1 is connected.

  The CPU 1 of the operation board 10 corresponds to the user's operation on the operation board 10, reads the numeric key press, generates the input numeric data, reads the start key press, and sends a start instruction to the controller board 400. It performs normal operation reading and display output control of copiers such as transfer and reading of paper size switching input.

  In the ROM 2, in addition to the operation program of the CPU 1, the distribution of on / off signals instructing light emission / non-light emission of each pixel and the display gradation of the pixel block of a pixel block composed of a plurality of pixels in the horizontal and vertical directions are displayed. A basic pattern group composed of a plurality of light emission pattern data expressing different gradations is stored.

  FIG. 10 shows pixel block data (grayscale expression pattern) in each group of the basic pattern groups GPTNA, GPTNB, GPTNC, and GPTND stored in the ROM 2. In this embodiment, the size of the pixel block is a 4 × 4 pixel matrix, and one bit is assigned to one pixel. “1” of the bit indicates display (lighting; on), and “0” indicates non-display (lighting off: off).

  As shown in FIG. 12A, when each bit addressed to each pixel of one pixel block is expressed as ap, the 16-bit data of one pixel block actually stored in the memory is ( This is 2-byte data shown in b).

  Please refer to FIG. 10 and FIG. As shown in FIG. 10, each basic pattern group (for example, GPTNA) is composed of 16 pixel block data (GPTNA0 to GPTNA15; pattern data) representing each gradation of 0 to 15, but the ROM 2 includes As shown in FIG. 11, the four groups of pixel block data are addressed to the basic group Nos. 0 to 3 (represented by Nbg in FIG. 9).

  Referring to FIG. 8 again, the pixel block data (FIG. 11) stored in the ROM 2 is the pattern register Prg assigned by the CPU 1 to the memory area of the RAM 3 in the initialization when the operating voltage is applied to the operation board 10. (FIG. 9) is written and used for subsequent gradation display. The display data (gradation data) is written in the VRAM 7 and is synchronized with the horizontal block synchronization signal of the raster display of the LCD 11 (the count over signal of the pixel counter 44 in FIG. 9: one pulse for every four pulses of the pixel synchronization signal). Then, it is read from the VRAM 7 by the LCDC 6 and used as a read address for the pixel block data in the pattern register Prg. The pixel block data read from the pattern register Prg is output from the LCDC 6 to the LCD 11 in accordance with a raster display pixel synchronization signal (pixel synchronization pulse) of the LCD 11.

  FIG. 9 shows an outline of the functional configuration of the LCDC 6. The display data stored in the VRAM 7 and read out by the LCDC 6 has a 16-bit (2 bytes) configuration, and monochrome display gradation data is stored in the 16-bit LSB side 5 bits. When the image data separation 60 is instructed to display 32 gradations, the 16-bit LSB side 5 bits read from the VRAM 7 are extracted as gradation data and output to the 16/32 gradation switching control 61 to display the 16 gradations. Is instructed, the 16-bit LSB side 4 bits read from the VRAM 7 are extracted as gradation data and output to the 16/32 gradation switching control 61.

  When the 16/32 gradation switching control 61 is instructed to display 32 gradations, the input 32 gradation data (5 bits) is output as it is from the data selector 63 as address designation data of the pattern register Prg. When 16-gradation display is instructed, the input 16-gradation data (4 bits) is converted into 32-gradation data by the data converter 62 and output from the data selector 63 to output the address designation data of the pattern register Prg. To do.

  FIG. 12C shows the configuration of the data conversion 62. This data conversion 62 doubles the 4-bit gradation data by bit digit shift and adds a numerical value 1 to convert the 16 gradation values to 32 gradation values as shown in FIG. However, in order to prevent the gradation 0 of 16 gradation expression from becoming the gradation 1 of 32 gradation expression by adding the numerical value 1, in the case of the gradation 0 of 16 gradation expression, the NAND gate 46a uses the 16th floor. Gradation expression gradation 0 is detected. In this case, the AND gate 46 is closed and the least significant bit of the 32 gradation output data is set to 0.

  Refer to FIG. 9 again. The timing control 40 includes a pixel synchronization signal generation 41 for generating a pixel synchronization signal that divides the display on the LCD 11 in the pixel (pixel) unit in the horizontal direction (x), and the display on the LCD 11 in the pixel (line) unit in the vertical direction (y). There are a horizontal synchronization signal generation 42 for generating a horizontal synchronization signal divided by, and a vertical synchronization signal generation 43 for generating a vertical synchronization signal representing switching of the display screen (frame) of the LCD 11. In the present embodiment, 32 gradation expression is performed using a 16 × gradation 4 × 4 pixel matrix (pixel block: on the display surface of the LCD 11), so the horizontal pixel counter 44 counts pixel synchronization signals (pulses). Thus, the pixel position data Xp in the horizontal direction within the pixel block is generated, the vertical synchronization signal (pulse) is counted by the vertical pixel counter 45, and the pixel position data Yp in the vertical direction within the pixel block is generated. Each of the counters 44 and 45 is a cyclic counter that returns to the count value 0 when the input pulse is counted up to the count value 4, outputs a count over signal (pulse), and counts up from the count value 0. Accordingly, the count over signal of the horizontal pixel counter 44 represents a horizontal pixel block delimiter, and the count over signal of the vertical pixel counter 45 represents a vertical pixel block delimiter.

  The horizontal block counter 46 counts the count over signal of the horizontal pixel counter 44. The counter 46 is also a circulation counter that repeatedly counts 0 to 3. The count data Xb of the counter 46 represents the horizontal position in the “section” which is a 4 × 4 pixel block matrix of the pixel block having the current raster scanning point of the display energizing of the LCD 11. The vertical block counter 47 counts the count over signal from the vertical pixel counter 45. The counter 47 is also a circulation counter that repeatedly counts 0 to 3. The count data Yb of the counter 47 represents the vertical position in the “section” (4 × 4 pixel block matrix) of the pixel block having the current raster scanning point of display energization of the LCD 11.

  The encoder 51 of the intermediate process 50 receives the count data Xb and Yb of the horizontal block counter 46 and the vertical block counter 47 as the block number in the section. The data Nb representing 0 to 15 is encoded (encoded).

  In the gradation display control, each of 16 types of pattern groups is assigned to each of the pixel blocks 0 to 15 in the section. In the first embodiment, the pattern groups are stored in the ROM 2 and written to the pattern register Prg of the RAM 3 for use. There are only four pattern groups GPTNA, GPTNB, GPTNC, and GPTND. These are called basic pattern groups.

  Therefore, in this first embodiment, there are three basic pattern groups: a pattern group rotated 90 ° to the right, a pattern group rotated 180 ° to the right, and a pattern group rotated 270 ° to the right by the rotation 55 shown in FIG. The pattern group is generated. These three types of pattern groups are called rotation pattern groups. Since three types of pattern groups are generated from each basic pattern group, 12 types of rotation pattern groups can be formed. If four basic pattern groups are added to this, there will be a total of 16 pattern groups. Therefore, each group of 16 pattern groups is assigned to each block 0 to 15 in one section (4 × 4 pixel block). Can do.

  FIG. 13B shows the configuration of the rotation 55. The right rotation 90 ° of the rotation 55 is obtained by rotating the 2-byte data which is the pixel block data a to p (1 bit each) shown in FIG. 12A by 90 ° to the right shown in the left end of FIG. This is conversion of the position of the bit signal line shown as 55a in FIG. 13B, which is converted into 2-byte data which is pixel block data. The rotation 180 ° to the right converts the 2-byte data that is the pixel block data shown in FIG. 12A to the 2-byte data that is the pixel block data rotated 180 ° to the right shown in the center of FIG. , The position of the bit signal line shown as 55b in FIG. The right 270 ° rotation converts the 2-byte data that is the pixel block data shown in FIG. 12A to the 2-byte data that is the pixel block data rotated 270 ° to the right shown in the right end of FIG. , The position of the bit signal line shown as 55c in FIG. FIG. 13B shows a rotation configuration in which rotated data is output by exchanging the positions of the bit signal lines. Similar rotation can be performed by data processing for exchanging bit data. it can.

  FIG. 14 shows a data selector 56 (after rotation 55) read from the pattern register Prg corresponding to 32 gradation data representing gradation 9 (hereinafter referred to as 9/32 gradation data) B. The data of each pixel block of 16 pixel blocks in one section output from FIG. The data selector 56 corresponds to the horizontal block position (Xbs) in the section, and when the raster scan position of the LCD 11 is the first horizontal block (0 position) in the section, the pixel block of the basic pattern group When the data (basic pattern) is the second block (1 position) in the horizontal direction, the pixel block data (rotation pattern 1) of the rotation pattern group rotated 90 ° to the right is used, and the third block (2 positions) in the horizontal direction. Pixel block data (rotation pattern 2) of the rotation pattern group rotated 180 ° to the right in the case of, and pixel block data (rotation pattern) of the rotation pattern group rotated 270 ° to the right in the case of the fourth block (3 positions) in the horizontal direction. Pattern 3) is selected and output.

  In this way, even with 32 gradation data, the gradation expression is switched with a small area (4 × 4 pixel matrix), and even if the gradation is the same within a section (4 × 4 pixel block), it is ON. Since the patterns are sequentially switched to different patterns (groups), the possibility of causing flicker or moire is low.

  This will be described more specifically. Assume that 0 to 15 and a block number are assigned to each block in the section as shown in the block of the encoder 51 in FIG. Nb indicates this block number, the horizontal direction on the drawing in FIG. 9 is the horizontal direction, and the vertical direction is the vertical direction. For 9/32 gradation data B, from the basic pattern group (FIG. 11) held in the pattern register Prg, blocks 0-3 are GPTNA05 patterns, blocks 4-7 are GPTNB05 patterns, blocks 8-11. The GPTNC05 pattern is applied to the block 12 and the GPTND05 pattern is applied to the blocks 12 to 15, respectively.

In block 0, the GPTNA05 pattern is read from the pattern register Prg and output as it is from the selector 56,
In block 1, the GPTNA05 pattern is rotated 90 ° right by rotation 55 and output from the selector 56,
In block 2, the GPTNA05 pattern is rotated 180 ° to the right by rotation 55 and output from selector 56.
In block 3, the GPTNA05 pattern is rotated 270 ° to the right by the rotation 55 and is output from the selector 56.

In block 4, the GPTNB05 pattern is read from the pattern register Prg, and is output as it is from the selector 56.
In block 5, the GPTNB05 pattern is rotated 90 ° to the right with rotation 55 and output from selector 56,
In block 6, the GPTNB05 pattern is rotated 180 ° to the right by rotation 55 and output from selector 56,
In block 7, the GPTNB05 pattern is rotated 270 ° to the right by the rotation 55 and output from the selector 56.

In block 8, the GPTNC05 pattern is read from the pattern register Prg and output as it is from the selector 56.
In block 9, the GPTNC05 pattern is rotated 90 ° to the right with rotation 55 and output from selector 56,
In block 10, the GPTNC05 pattern is rotated 180 ° to the right by rotation 55 and output from selector 56,
In block 11, the GPTNC05 pattern is rotated 270 ° to the right by the rotation 55 and output from the selector 56.

In block 12, the GPTND05 pattern is read from the pattern register Prg and output as it is from the selector 56.
In block 13, the GPTND05 pattern is rotated 90 ° to the right with rotation 55 and output from selector 56,
In block 14, the GPTND05 pattern is rotated 180 ° to the right at rotation 55 and output from selector 56,
In block 15, the GPTND05 pattern is rotated 270 ° to the right by the rotation 55 and is output from the selector 56.

  In this way, 16 4 × 4 pixel blocks are generated based on the gradation patterns GPTNA05, GPTNB05, GPTNC05, and GPTND05 of the basic pattern group.

  In the first embodiment, in order to further reduce the possibility of occurrence of flicker and moire, the pattern group allocation position in the section is changed every time the frame is switched. In order to realize this, the block number allocation position in the section is shifted as shown in FIG. 15, and 16 frames are set as one order unit. This is performed by the frame counter 48, addition 52, decoder 53 and encoder 54 shown in FIG.

  Referring back to FIG. 9, the frame counter 48 is a cyclic counter that counts the vertical synchronization signal, initializes the count value to 0 when the count value reaches 16, and counts the vertical synchronization signal. A value of 0 to 15 is represented. An adder 52 adds the block number data Nb output from the encoder 51 and the frame number count data Nc, and decodes the block number data Nbc with only the lower 4 bits representing only the value of 0 to 15 of the added data. To 53. This block number data Nbc becomes the block number (number in the minor grid) shown in FIG. 15 that changes every time the frame is switched. Since the pattern group is designated by this block number, the pattern group allocation position in the section changes in synchronization with the frame switching.

  In the decoder 53, the block number represented by the data Nbc is in the range of 0 to 3 to which the first basic pattern group GPTNA (basic pattern) or its rotation data group (rotation patterns 1 to 3) is assigned, or the second basic pattern group GPTNB or A range of 4 to 7 to which the rotation data is assigned, a range of 4 to 7 to which the third basic pattern group GPTNC or the rotation data is assigned, or a range of 8 to 11 to which the fourth basic pattern group GPTND or the rotation data is assigned. Is detected and a detection signal is output to the encoder 54. The encoder 54 converts the detection signal into basic pattern group designation data Nbg representing 0 to 3, and supplies the basic pattern group designation data to the pattern register Prg. The designated data Nbg representing 0 designates the first basic pattern group GPTNA, and the designated data Nbg representing each of 1 to 3 are respectively the second basic pattern group GPTNB, the third basic pattern group GPTNC and the fourth basic pattern group. Specify GPTNC.

  The switching detection 69a detects switching of the designated data Nbg, that is, switching of the basic pattern group, and gives a clear pulse to the horizontal block counter 69b. In response to this clear pulse, the horizontal block counter 69b initializes the count data Xbs to the one representing the initial value 0, and the count over signal (horizontal block division pulse) of the horizontal pixel counter 44 is counted from that value. Resume.

  The count data Xbs output from the horizontal block counter 69b has a basic pattern (no rotation) when the intra-section block number Nbc (shown in FIG. 15) output from the addition 52 is 0, 4, 8, or 12. When the block number Nbc in the section is 1, 5, 9 or 13, the rotation is 90 ° to the right. When the block number Nbc in the section is 2, 6, 10 or 14, the right is 180 °. Rotation is specified as 2, and when the intra-section block number Nbc is 3, 7, 11, or 15, 3 is specified as 270 ° rotation to the right. Corresponding to the count data Xbs, the selector 56 selects pixel block data without rotation (basic pattern) or pixel block data Dbs rotated by 90 °, 180 ° or 270 ° (rotation pattern 1, 2 or 3), Output to selector 57.

  The selector 57 outputs the 2-byte pixel block data Dbs output from the selector 56 to the output control 70 one bit at a time in synchronization with the image synchronization signal. Serial output. That is, the pixel number data Xp representing the horizontal pixel position in the pixel block of the horizontal pixel counter 44 and the pixel (line) number representing the vertical pixel (line) position in the pixel block of the vertical pixel counter 45. The encoder 58 encodes the combination of data Yp (pixel position in the pixel block) into bit position data Np (0 to 15) in the pixel block data group having a 2-byte configuration shown in FIG. The selector 57 outputs the bit data Dp designated by the bit position data Np in the 2-byte pixel block data group. The output control 70 serially outputs the bit data Dp to the LCD 11 in synchronization with the display raster scan of the LCD 11.

  Reference is again made to FIG. First, in the first frame (first frame), the block 0 in the section is converted to the block number at the left end of the first row in the section using the block number in the section obtained by converting the count data Xb and Yb of the horizontal and vertical block counters 46 and 47. The block numbers are sequentially arranged, block 1 to the right of block 0, block 2 to the right of block 1, block 3 to the right of block 2, and so on. The block 4 is placed at the left end of the second row when the blocks 3 are arranged. After that, as in the first row, the block 5, the block 6, and the block 7 are sequentially arranged on the right side of the block 4. In the third row, a block 8 is arranged at the left end, and a block 9, a block 10, and a block 11 are arranged in order on the right side of the block 8. In the fourth row, a block 12 is arranged at the left end, and a block 13, a block 14, and a block 15 are arranged in order on the right side of the block 12.

  Next, in the second frame, the count data Nc of the frame counter 48 becomes 1, and the output of the adder 52 changes to indicate one larger value, so that each block number is shifted one by one to the left. That is, block 1 is arranged at the left end of the first line in the section, block 2 is arranged to the right of block 1, block 3 is arranged to the right of block 2, and block 4 is arranged to the right of block 3 from the second line. The After that, similarly, in the second row, the block 5 is arranged at the left end, and the block 6, the block 7, and the block 8 are arranged in order on the right side of the block 5. In the third row, a block 9 is arranged at the left end, and a block 10, a block 11, and a block 12 are arranged in order on the right side of the block 9. In the fourth row, the block 13 is arranged at the left end, the blocks 14 and 15 are arranged on the right side of the block 13, and the block 1 at the left end of the first row is arranged finally.

  Similarly, the third and subsequent frames are similarly shifted to the left one by one, and in the last 16th frame, the first row is arranged in the order of block 15, block 1, block 2, and block 3, In the second row, block 4, block 5, block 6, and block 7 are arranged in this order, and in the third row, block 8, block 9, block 10, and block 11 are arranged in this order, and in the fourth row, block 12 and block are arranged. 13, block 14 and block 15 are arranged in this order.

  As described above, since the block arrangement is shifted or rotated over a wide range (section), four basic pattern groups (blocks 0, 4, 8, and 12) and 12 rotation patterns obtained by rotating the basic pattern are used. A total of 16 pattern groups including groups (blocks 1, 5, 9, and 13 rotated 90 °, blocks 2, 6, 10, and 14 rotated 180 °, blocks 3, 7, 9, and 15 rotated 270 °) Are distributed in the section, and the position changes in the section at every frame switching.

  FIG. 16 shows the data output in one section of 9/32 gradation data B displayed by shifting the block number in the mode shown in FIG. 15, and FIG. 17 shows each pixel block in the section. The gradation ratio (number of lit pixels / total number of pixels) between 16 frames is shown. When block 0 to block 15 are used in one section, the lighting pixels (“1”) of the section that is a 16 × 16 pixel matrix have the distribution shown in FIG. Finally, the number of lighting times of each pixel is 5/16 times in the 9/32 gradation data B, and all the pixels in the 4 × 4 pixel matrix (pixel block) are lighted 5/16 times.

  FIG. 18 shows pixel block data read from the pattern register Prg by 32 gradation data (hereinafter referred to as 8/32 gradation data) B representing gradation 8 (even number). This is obtained by replacing the pixel block data shown in FIG. 14 representing gradation 9 (odd number) with that representing gradation 8. Regarding the gradation 8 (even number), only the data of the block 0 to the block 15 are different, and the other aspects are the same as those of the gradation 9. The control method is the same as in the 9/32 gradation described above. When the 8/32 gradation data B is given to the pattern register Prg, the GPTNA04 pattern is generated in the blocks 0 to 3, the GPTNB05 pattern in the blocks 4 to 7, and the GPTNC04 pattern in the blocks 8 to 11 from the pattern register Prg. In addition, the GPTND05 pattern is read in the blocks 12 to 15.

In block 0, the pixel block data of the GPTNA04 pattern read from the pattern register Prg is selected and output as it is from the selector 56,
In block 1, pixel block data obtained by rotating the GPTNA04 pattern 90 ° to the right with rotation 55 is selected and output from the selector 56,
In block 2, pixel block data obtained by rotating the GPTNA04 pattern 180 ° to the right is selected and output from the selector 56.
In block 3, pixel block data obtained by rotating the GPTNA04 pattern to the right by 270 ° is selected and output from the selector 56.

In block 4, the GPTNB05 pattern read from the pattern register Prg is selected and output from the selector 56 as it is.
In block 5, pixel block data obtained by rotating the GPTNB05 pattern 90 ° to the right is selected and output from the selector 56,
In block 6, pixel block data obtained by rotating the GPTNB05 pattern 180 ° to the right is selected and output from the selector 56,
In block 7, pixel block data obtained by rotating the GPTNB05 pattern to the right by 270 ° is selected and output from the selector 56.

In block 8, the GPTNC04 pattern read from the pattern register Prg is selected and output from the selector 56 as it is.
In block 9, pixel block data obtained by rotating the GPTNC04 pattern 90 ° to the right is selectively output from the selector 56,
In block 10, pixel block data obtained by rotating the GPTNC04 pattern 180 ° to the right is selected and output from the selector 56,
In block 11, pixel block data obtained by rotating the GPTNC04 pattern to the right by 270 ° is selected and output from the selector 56.

In block 12, the GPTND05 pattern read from the pattern register Prg is selected and output from the selector 56 as it is,
In block 13, pixel block data obtained by rotating the GPTND05 pattern 90 ° to the right is selected and output from the selector 56,
In block 14, pixel block data obtained by rotating the GPTND05 pattern 180 ° to the right is selected and output from the selector 56,
In block 15, pixel block data obtained by rotating the GPTND05 pattern to the right by 270 ° is selected and output from the selector 56.

  In this manner, 16 pixel blocks are generated and output based on the gradation patterns of GPTNA04, GPTNB05, GPTNC04, and GPTND05. For the other even gradations in 32 gradations, pattern data of blocks 0 to 15 is generated in the same manner as the pixel block data is read from the pattern register Prg with the above-mentioned 8/32 gradation data B. And output.

  FIG. 19 shows display data of one section based on 8/32 gradation data B displayed by the block number shift interlocking with frame switching shown in FIG. 15, and FIG. FIG. 19) shows the gradation ratio (number of lit pixels / total number of pixels) during 16 frame display. When block 0 to block 15 are used in one section, the lighting pixels (“1”) of the section that is a 16 × 16 pixel matrix have the distribution shown in FIG. Finally, the number of lighting times of each pixel is 4/16 times or 5/16 times in the 8/32 gradation data B. In all 16 pixels of the 4 × 4 pixel matrix (pixel block), 8 pixels are lit 4/16 times, and the remaining 8 pixels are lit 5/16 times. When the number of times of lighting is viewed for the entire 4 × 4 pixels, the state of lighting is 4.5 / 16 times (9/32 times).

  Since the 16/32 gradation switching control 61 converts 16 gradation data into 32 gradation data, in the case of 16 gradation data, the gradation value (density 0 to 0) of the 16 gradation terms shown in FIG. Only the pattern data of the same gradation of the basic pattern group assigned to 15) is output. All the pattern data of each basic pattern group addressed to one gradation represent the same gradation. Therefore, in the case of 16 gradation expression, basic gradation display is performed.

  When 32 gradation data is given, the odd value gradation data is assigned to the odd value gradation because the pattern data representing the same gradation of each basic pattern group expressed in 16 gradations is assigned. And basic gradation display. However, since pattern data representing the same gradation of each basic pattern group cannot be assigned to even value gradations, each half of each of four pattern data addressed to each odd value gradation before and after the even value ( 2) is assigned (the even-numbered density row in the term of 32 gradations in FIG. 11), so that even-value gradation data is given, the quasi-gradation display is performed.

  In the first embodiment shown in FIG. 9, the pixel block data a to p are output from the selector 57 bit by bit in synchronization with the pixel synchronization signal, but the display data is the count data Xa ( Since one pixel is read from the VRAM 7 by being accessed with the count data ya (representing the vertical pixel block number on one frame) of the vertical block counter 68 and the horizontal pixel block number on one frame) One display data A read from the VRAM 7 corresponds to a 4 × 4 display pixel of the LCD 11. If one display data A is assumed to be associated with one display pixel, the display is enlarged 4 × 4 times the assumed screen size. In order to make this display 1 time, the horizontal block counter 67 is changed to a horizontal pixel counter that counts the pixel synchronization signal and is cleared by the horizontal synchronization signal, or changes the count clock to the pixel synchronization signal and Change the clear signal to a horizontal sync signal, and further change the vertical block counter 68 to a vertical pixel counter that counts the horizontal sync signal and is cleared by the vertical sync signal, or changes the count clock to a horizontal sync signal and Change the clear signal to the vertical sync signal.

  If the block number shift (FIG. 15) linked to the frame switching is not performed, the selector 56 may be switched based on the count data Xb of the horizontal block counter 46 instead of Xbs. The pattern register Prg can be supplied with count data Yb of the vertical block counter 47 instead of Nbg, and the addition 52, decoder 53, encoder 54, switching detection 69a and horizontal block counter 69b can be deleted.

  FIG. 21 shows a second embodiment applied to R, G, B color display. This is because the LCDC 6 of the first embodiment shown in FIG. 9 is provided with 16/32 gradation switching control 61 and halftone processing 50, which are roughly one set each for R, G and B, for a total of three sets. In addition, the G phase shift value register 64 and the B phase shift value register 65 are added, and the phase shift value of the G phase shift value register 64 is added to the addition (52) of the halftone process for G. The phase shift value of the phase value register 65 is added to the addition (52) of the halftone process for B. The encoder (51) can be shared by three sets of halftone processing.

  At the time of color display, display data in which R (red) is 5 bits, G (green) is 6 bits, and B (blue) is 5 bits from the MSB side of 16 bits / pixel is stored in the VRAM 7. When the display data read from the VRAM 7 is display data of 32 gradations, the image data separation 60 converts the display data into 5 bits for R (red), 6 bits for G (green), and 5 bits for B (blue). The MSB side 5 bits are extracted for each color, and output to the pattern register 3 as gradation data Br, Bg, Bb.

  In the case of 16-gradation display data, the image data separation 60 divides the display data into 5 bits for R (red), 6 bits for G (green), and 5 bits for B (blue). 4 bits are taken out and output to the pattern register 3 as gradation data Br, Bg, Bb of 5 bits by the 16/32 gradation switching control 61.

  The halftone processing addressed to each group (each color) of the halftone processing 50 performs the pattern data read out output described above with reference to FIGS. In addition, the phase shift value in the G phase shift value register 64 is added to the halftone process for G so that the gradation on / off patterns (pixel block pattern data) of the R, G, and B colors are not the same. In addition to (52), the phase shift value of the B phase shift value register 65 is added to the addition (52) of the halftone process for B so that the block numbers designated between colors are different.

  FIG. 22 shows a block number shift in a section linked with frame switching in color display. In the illustrated example, the phase shift value of the G phase shift value register 64 is 5 and the phase shift value of the B phase shift value register 65 is 10. The arrangement of block 0 to block 15 in the R display control is the same as in FIG. In the display control of G, when the phase shift value 5 is set in the G phase shift value register 64, the block 5 is arranged at the left end of the first row of the section, and the blocks 6 and 5 are arranged. The seventh and fourth lines are arranged sequentially. As for the arrangement of blocks 0 to 15 in the display control of B, when the phase shift value 10 is set in the B phase shift value register 65, the block 10 is arranged at the left end of the first row of the section. And up to the fourth line. By doing so, the R, G, B gradation on / off patterns at the arrangement positions of the blocks are all different patterns at the same time point.

  Other configurations and functions of the second embodiment are the same as those of the first embodiment shown in FIGS.

  FIG. 23 shows the configuration of the LCDC 6 of the third embodiment. In the third embodiment, the output mode of only the light emission pattern data of the basic pattern group that does not use the rotation 55 and the output mode of the basic pattern group and the rotation pattern group of the first embodiment can be selected. . In the third embodiment, this selection is realized by a signal switching 66 that selectively fixes the selection signal Xbs supplied to the selector 56 to data representing 0. The selection signal Xbs given to the selector 56 by the horizontal block counter 69b is 2-bit data indicating a numerical value of 0 to 3, and when it is data representing 0, the selector 56 outputs one pixel block output from the pattern register Prg. The 16-bit (2 bytes) data is output to the subsequent selector 57 as it is.

  When the CPU 1 gives a signal L designating the output mode of only the light emission pattern data of the basic pattern group to the signal switching 66, the signal switching 66 applies 2 bits of the selection signal Xbs, which is 2-bit data, to each bit line. Change to L via the connected diode. As a result, Xbs given to the selector 56 is fixed to a value representing 0, and the selector 56 steadily outputs the 16-bit (2-byte) data of one pixel block output from the pattern register Prg as it is to the subsequent selector 57. Output. When the CPU 1 sets the signal applied to the signal switching 66 to H, Xbs given to the selector 56 becomes count data of the horizontal block counter 69b, and the value changes every time the pixel block in the horizontal direction is switched. 56 is the basic pattern data of one pixel block output from the pattern register Prg in sequence in synchronization with the switching of the pixel blocks in the horizontal direction, the rotation pattern data rotated 90 ° to the right, and the rotation rotated 180 ° to the right The pattern data 2 and the rotation pattern data 3 rotated 270 ° to the right are cyclically output sequentially in this order.

  Note that the L / H of the signal that the CPU 1 gives to the signal switching 66 is selected and specified by the user on the input screen of the initial setting menu of the operation board in the initial setting menu that the user operates by operating the initial setting key 18.

  Other configurations and functions of the third embodiment are the same as those of the first embodiment shown in FIGS.

  FIG. 24 shows a hardware portion of the fourth embodiment different from that of the first embodiment. In the fourth embodiment, the rotation 55 and the selector 56 are applied with an operating voltage on the operation board 10, and in response to this, the CPU 1 performs initialization, and the basic pattern group pixel block in the ROM 2 (FIG. 8). When writing data into the pattern register Prg, the pixel block data of the basic pattern group is rotated, the basic pattern data of one pixel block, the rotated pattern data rotated 90 ° to the right, and the rotated pattern rotated 180 ° to the right Data 2 and rotation pattern data 3 rotated 270 ° to the right are sequentially written in this order.

  As a result, even if the pattern data storage capacity of the ROM 2 is small enough to hold only four basic pattern groups, the pattern register Prg has four basic pattern groups and twelve rotational pattern groups. Is retained. Each of the 12 types of rotation patterns is specified by the count data Xbs of the horizontal block counter 69b. In the fourth embodiment, the pattern register Prg stores 4 types of basic pattern data and 12 types of rotation pattern data for the gradation represented by the 32 gradation data B. The specified data Nbg and the rotation angle instruction data Xbs are used to specify the pattern data of one pixel block, read from the pattern register Prg, and provided to the selector 57.

  Other configurations and functions of the fourth embodiment are the same as those of the first embodiment shown in FIGS.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an outline of a mechanism of a multi-function copying machine MF1 including an operation board 10 equipped with a gradation display device according to a first embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of a color scanner 100 and an ADF 120 shown in FIG. FIG. 2 is an enlarged vertical sectional view of the color printer 200 shown in FIG. 1. FIG. 2 is a block diagram showing a configuration of an image processing system in the copying machine MF1 shown in FIG. FIG. 5 is a block diagram illustrating a functional configuration of scanner image processing 303 and printer image processing 304 illustrated in FIG. 4. FIG. 2 is an enlarged plan view showing a part of an upper surface of an operation board 10 of the copying machine MF1 shown in FIG. (A) is an enlarged plan view showing a “read” input screen displayed on the liquid crystal display 11 of the operation board 10 when “read” is input to the operation board 10, and (b) is an image obtained by reading a document. It is an enlarged plan view which shows the image display screen which displayed. 3 is a block diagram showing an outline of a configuration of an electric system of the operation board 10. FIG. It is a block diagram which shows the outline | summary of the function structure of LCDC (display controller) 6 shown in FIG. FIG. 10 is a block diagram showing pixel block data of a basic pattern group stored in the ROM 2 shown in FIG. 8 and written in the pattern register Prg shown in FIG. 9 set in the RAM 3 in association with the intra-block pixel distribution. It is a table | surface which shows the identification symbol of the pattern data in the basic pattern group allocated to the gradation value. (A) is a plan view of a bit distribution pattern in which each display bit addressed to each pixel in one pixel block is indicated by symbols a to p, and (b) is a bit a addressed to one pixel block in (a). FIG. 10C is a block diagram illustrating a bit arrangement in memory read / write and data transfer, and FIG. 9C is a block diagram illustrating a configuration of the data conversion 62 illustrated in FIG. 9. FIG. 12A is a plan view showing a rotated bit arrangement obtained by rotating the bit arrangement in one pixel block shown in FIG. 12A by 90 ° to the right, 180 ° to the right, and 270 ° to the right, and FIG. 10 is a plan view showing the configuration of a right 90 ° rotating portion 55a, a right 180 ° rotating portion 55b, and a right 270 ° rotating portion 55c of the rotation 55 shown in FIG. The basic pattern data of the basic pattern group read to the gradation value 9 from the pattern register Prg shown in FIG. 9 and the rotated pattern data obtained by rotating the basic pattern group include 16 types, one section (4 × 4 blocks). It is a block diagram which shows the pattern group arranged in the inside. It is a top view which shows the arrangement | sequence of the block number in a section represented by the output data Nbc of the addition 52 shown in FIG. 9, and each block number on FIG. 15 shows each pattern of 16 types of pattern groups shown in FIG. To express. FIG. 16 is a plan view showing a display data distribution addressed to a gradation value of 9 within one section generated by the block number arrangement shown in FIG. 15, where “1” indicates lighting of one pixel, and “0” indicates lighting off. Instruct. FIG. 17 is a chart showing a gradation ratio (number of lit pixels / total number of pixels) of each pixel block expressed in a 16-frame period by switching display data distribution in conjunction with frame switching shown in FIG. 16. The basic pattern data of the basic pattern group read to the gradation value 8 from the pattern register Prg shown in FIG. 9 and the rotated pattern data obtained by rotating the basic pattern group are 16 types, one section (4 × 4 blocks). It is a block diagram which shows the pattern group arranged in the inside. FIG. 16 is a plan view showing a display data distribution addressed to a gradation value of 8 within one section generated by the block number array shown in FIG. 15, where “1” indicates lighting of one pixel, and “0” indicates lighting off. Instruct. FIG. 20 is a chart showing a gradation ratio (the number of lit pixels / the total number of pixels) of each pixel block expressed in a 16-frame period by switching the display data distribution in conjunction with the frame switching shown in FIG. 19. FIG. It is a block diagram which shows the principal part of the color gradation display apparatus of 2nd Example of this invention. It is a top view which shows the arrangement | sequence of the block number in a section in each of the R, G, B halftone process shown in FIG. It is a block diagram which shows the principal part of the gradation display apparatus of 3rd Example of this invention. It is a block diagram which shows the principal part of the gradation display apparatus of 4th Example of this invention.

101: contact glass 102: illumination lamp 103: first mirror 104: second mirror 105: third mirror 106: lens 107: CCD 108: pulse motor 109: base point sensor 110: reference white plate 111: scale 112: pressure plate switch 121: Document tray 125: Conveying drum 126: Conveying belt 130: Filler sensor 131: Side plate position detection switch 132: Glass 137: Pressure plate 201: Photoconductor 202: Charging device 203: Exposure device
204, 207: Developing device
208, 215: transfer belts 209 to 211: paper feed cassette 214: fixing device 224: paper discharge guide 225: paper discharge roller 226: paper discharge stack 227: replenishment toner storage 233: registration roller

Claims (13)

A two-dimensional display means having a display surface that expands in the horizontal and vertical directions, and performing display / non-display on the display surface in units of pixels of the ON / OFF signal section;
In the pixel block composed of a plurality of pixels in the horizontal and vertical directions, the distribution of the on / off signal instructing the light emission / non-light emission of each pixel and the display gradation of the pixel block are represented, each representing a different gradation. A gradation memory that stores a plurality of light emission pattern data as one group and stores a basic pattern group composed of a plurality of groups having different distribution patterns of the on / off signal for each group;
Means for changing the group indication signal on the display frame, each Ri switching means and vertical picture element blocks to change the rotational angle instruction signal for each Ri switching picture element blocks water square direction;
Means for reading light emission pattern data corresponding to gradation data of a basic pattern group corresponding to the group instruction signal from the gradation memory;
Rotating means for converting the read light emission pattern data into light emission pattern data of an on / off signal distribution rotated by an angle corresponding to the rotation angle instruction signal; and
Means for outputting on / off signals of the light emission pattern data converted by the rotating means to the two-dimensional display means;
A gradation display device comprising: A two-dimensional display means having a display surface that expands in the horizontal and vertical directions, and performing display / non-display on the display surface in units of pixels of the ON / OFF signal section;
In the pixel block composed of a plurality of pixels in the horizontal and vertical directions, the distribution of the on / off signal instructing the light emission / non-light emission of each pixel and the display gradation of the pixel block are represented, each representing a different gradation. A non-volatile memory in which a plurality of light emission pattern data is set as one group and a basic pattern group including a plurality of groups having different distribution patterns of the on / off signal for each group is stored;
Rotating means for converting each light emission pattern data read from the nonvolatile memory into light emission pattern data having an ON / OFF signal distribution rotated by a plurality of different angles and writing the data in the gradation memory;
Means for changing the group indication signal on the display frame, each Ri switching means and vertical picture element blocks to change the rotational angle instruction signal for each Ri switching picture element blocks water square direction;
Means for reading out light emission pattern data corresponding to the group instruction signal, gradation data and rotation angle instruction signal from the gradation memory; and
Means for outputting an ON / OFF signal of the read light emission pattern data to the two-dimensional display means;
A gradation display device comprising: The means for changing the rotation angle instruction signal includes a horizontal pixel counter comprising a circulation counter that counts the pixel synchronization signal and counts the number of pixels in the horizontal direction in the pixel block to initialize and count the count data; and The number of times of initialization of the horizontal pixel counter is counted, the count value is initialized in synchronization with the switching of the group instruction signal, the number of times of initialization of the horizontal pixel counter is counted, and the count data is used as the rotation angle instruction signal. A horizontal block counter that outputs as
The means for changing the group instruction signal includes a vertical pixel counter comprising a circulation counter that counts horizontal synchronization signals and counts the number of pixels in the vertical direction in the pixel block to initialize and count the count data, and the vertical counter 3. A vertical block counter that counts the number of times of initialization of the pixel counter and counts the first set value to initialize the counter and outputs count data as a signal for changing the group instruction signal is included. The gradation display device described in 1. The means for reading the light emission pattern data from the gradation memory counts the number of times of initialization of the horizontal pixel counter, counts the second set value, initializes the count value, and counts the horizontal block counter count data. Based on the count data of the vertical block counter, an encoder for generating a block number in a section consisting of the number of pixel blocks of the second set value in the horizontal direction and the number of pixel blocks of the first set value in the vertical direction, and the number of frames 4. A frame counter according to claim 3 , further comprising: a frame counter for counting; an adding means for adding the block number and a frame count value of the frame counter; and means for converting the added output data of the adding means into a group instruction signal; Tone display device. 5. A means for reading the light emission pattern data from the gradation memory according to claim 4 is provided for each display of R, G and B gradation data, for a total of three sets; 5. The color gradation display device according to claim 4 , further comprising means for adding a phase shift value for making the added output data different from the other set. Wherein an output of only the light-emitting pattern data of the basic pattern groups that do not use rotating means, means for selecting the output used in combination emission pattern data obtained by rotating by the rotation means; further comprising any one of claims 1 to 5 The gradation display device described in 1. The basic pattern group is a light emission pattern data group representing each gradation in a narrow gradation range that is half of the wide gradation range represented by the gradation data;
Each gradation of the wide gradation range includes a plurality of light emission pattern data of the basic pattern group, each of which is associated with the group instruction signal , and a plurality of gradations represent the gradation of the wide gradation range. Multiple emission pattern data are assigned;
Means for reading light emission pattern data from the gradation memory reads light emission pattern data corresponding to the group instruction signal ;
The gradation display device according to claim 1. Light emission pattern data addressed to the same gradation of the plurality of basic pattern groups in the low gradation range is assigned to one of the even value gradation and the odd value gradation in the wide gradation range, and the other 8. The gradation display device according to claim 7 , wherein light emission pattern data addressed to different gradations of a plurality of basic pattern groups is assigned. The means for reading the light emission pattern data from the gradation memory converts the narrow range gradation data representing a narrower range of gradations than the wide range of gradations represented by the gradation data into the gradation data representing the wide range of gradations. It means for converting; including, gray scale display device according to any one of claims 1 to 8. An imaging device that converts a light image into image data representing it; and
Optical image reading apparatus including a; displays image data imaging device generates the two-dimensional display unit, the gradation display according to any one of claims 1 to 9. A document scanner that reads an image of the document and generates image data representing the image; and
Original reading apparatus comprising; displaying the image data which the document scanner is generated in the two-dimensional display unit, the gradation display according to any one of claims 1 to 9. The document reading device according to claim 11 ;
A printer that forms an image represented by the image data on paper; and
An image forming apparatus comprising: image data processing means for converting image data generated by the document reading apparatus into image data suitable for image forming characteristics of the printer. The image forming apparatus according to claim 12 , wherein the gradation display device is in an operation terminal that gives a user instruction to the image forming apparatus.

Images