JP2006130890A - Image writing device/method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image writing device which can highly precisely correct a light emitting element array in its joint, can be constituted at a low cost and is best-suited for rapidly transferring image data. <P>SOLUTION: A part 12 for controlling the transfer of data for LPH1 roughly adjusts the pixel positions 8 of image data in the unit of 8 bits by controlling the address of a data import control part 10 which writes the image data, in the unit of 8 bits, in line memory 11-1 for LPH1, line memory 11-2 for LPH2 and line memory 11-3 for LPH3, and controls the transfer of data for LPH1 to the light emitting element array (LPH1). A part 20 for controlling the transfer of data for LPH3 controls the transfer of data for LPH3 to the light emitting element array (LPH3). Thus pixel positions of the image data are finely adjusted in the unit of one bit by the transfer control of the part 12 and the part 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image writing apparatus and method for an image forming apparatus such as an electrophotographic printer, and more particularly to a connection between light emitting element arrays in an image forming apparatus in which a plurality of light emitting element arrays are arranged in a staggered manner with respect to a photoreceptor. The present invention relates to an image writing apparatus and method capable of effectively correcting image quality defects caused by mechanical attachment displacement of an eye part.

  In general, an image forming apparatus such as an electrophotographic printer employs an optical writing method in which an electrostatic latent image is written by irradiating light to a photosensitive member. As an image writing apparatus for performing this optical writing, conventionally, a laser beam is reflected by using a polygon mirror and optical scanning is performed in the main scanning direction, and a light emitting element array such as an LED array is arranged in the main scanning direction. A scanning method is known.

  Here, the image writing device by scanning using the light emitting element array can achieve downsizing of the device because an optical space for deflecting and scanning the light beam in the main scanning direction is unnecessary. Therefore, a light emitting element array that is longer than the image writing width is required.

  However, it is difficult to provide a long light emitting element array at a low cost due to production yield and the like.

  Therefore, an image writing apparatus has been proposed in which a plurality of light emitting element arrays are arranged in a staggered manner in the main scanning direction of the photosensitive member. According to the image writing apparatus using the plurality of light emitting element arrays, it is possible to write an image using an inexpensive light emitting element array. There is a problem that an image quality defect occurs in the portion.

  That is, when a gap is formed in the joint portion of the light emitting element array, white stripes are generated in this portion, and when the joint portion of the light emitting element array is overlapped, an image quality defect in which black stripes are generated in this portion occurs.

A technique described in Patent Document 1 is known as a technique for solving this problem. In the device disclosed in Patent Document 1, the output position in the main scanning direction can be arbitrarily changed by address control of a storage means for storing an image signal in a predetermined pixel unit. Light emission is performed by this address control. Adjustments at the joints of the element array and margin adjustments at the edge of the sheet can be performed.
JP 2003-226036 A

  However, since the apparatus disclosed in Patent Document 1 adjusts the output position in the main scanning direction by address control of the storage means, it can only adjust in units of the number of pixels stored in each address of the storage means.

  In other words, if the number of pixels stored in each address of the storage means is large, the storage capacity of the storage means may be small, but correction at the joints of the light emitting element arrays cannot be performed with high accuracy, resulting in satisfactory image quality. I can't.

  Further, if the number of pixels stored in each address of the storage means is reduced, the accuracy of correction at the joint of the light emitting element arrays can be increased, but a large-capacity storage means is required, resulting in an increase in cost. Further, it is not suitable for high-speed transfer of image data.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides an image writing apparatus and method that can perform correction with high accuracy at the joint of the light emitting element array, can be configured at low cost, and is also suitable for high-speed transfer of image data. With the goal.

  In order to achieve the above object, according to the first aspect of the present invention, a plurality of light emitting element arrays in which light emitting elements are arranged in the main scanning operation direction are arranged in a staggered manner with respect to the photoreceptor, and image data is stored in the plurality of light emitting element arrays. Is divided and transferred to cause the light emitting elements of the plurality of light emitting element arrays to emit light corresponding to the image data, and to write an electrostatic latent image on the photoconductor by the light emission of the light emitting elements. A storage unit for writing the image data to each address in a predetermined pixel unit corresponding to the light emitting element array, and the image data from the storage unit by the addressing of the storage unit individually by the predetermined pixel. Data transfer means for capturing and transferring to the light emitting element array, and image data to be written to the storage means by address control of the storage means are adjusted in units of the predetermined pixels First adjusting means, and second adjusting means for adjusting image data to be transferred to the light emitting element array in units smaller than the predetermined pixel unit by transfer control of the data transfer means. Features.

  According to a second aspect of the present invention, in the first aspect of the present invention, the light emitting element array is arranged at a predetermined distance from the photoconductor in the sub-scanning direction, and the data transfer means is provided for each light emitting element array. The image data delay means for correcting the displacement of the respective arrangement positions in the sub-scanning direction is provided.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the first adjustment unit and the second adjustment unit are configured such that the image data at a joint portion in the main scanning direction of the light emitting element array. The pixel positions of the image data transferred to each light emitting element array are adjusted so that the pixel positions are continuous.

  According to a fourth aspect of the present invention, there is provided the method according to any one of the first to third aspects, wherein the first adjusting unit and the second adjusting unit are different from each other on the basis of one or more of the light emitting element arrays. The image data to be transferred to the light emitting element array is adjusted.

  According to a fifth aspect of the present invention, a plurality of light emitting element arrays in which light emitting elements are arranged in the main scanning operation direction are arranged in a staggered manner with respect to the photosensitive member, and image data is divided and transferred to the plurality of light emitting element arrays. In the image writing method of the image forming apparatus, the light emitting elements of the plurality of light emitting element arrays emit light corresponding to the image data, and an electrostatic latent image is written on the photoreceptor by light emission of the light emitting elements. The image data is written to each address of the storage means in a predetermined pixel unit, the image data is fetched from the storage means by the predetermined pixel by the address designation of the storage means, and transferred to the light emitting element array by the data transfer means. The image data to be written in the storage means by the address control of the storage means is adjusted by the first adjustment means in units of the predetermined pixels, and the data The transfer control transmission means and adjusting the image data to be transferred to the light emitting element array in units smaller than the predetermined pixel unit by the second adjustment means.

  According to the present invention, image data is written to each address of the storage means in a predetermined pixel unit, the image data is fetched from the storage means by a predetermined pixel by the address designation of the storage means, and transferred to the light emitting element array by the data transfer means. Then, the image data to be written to the storage means by the address control of the storage means is adjusted in a predetermined pixel unit by the first adjustment means, and the image data to be transferred to the light emitting element array by the transfer control of the data transfer means is the second adjustment. Since it is configured to adjust in units of one pixel by means, it is possible to perform correction with high accuracy at the joint of the light emitting element array, and it can be configured at low cost, and is also suitable for high-speed transfer of image data. It is possible to provide an insertion device and method.

  Hereinafter, an image writing apparatus and method according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing an embodiment of an image writing apparatus according to the present invention.

  The image writing apparatus shown in FIG. 1 is applied to an image writing apparatus of an image forming apparatus such as an electrophotographic printer. The image writing apparatus includes three pieces arranged in a staggered manner in the main scanning direction with respect to a photoreceptor not shown. Processing for writing an electrostatic latent image corresponding to input image data on the photoconductor by light emission control of the light emitting element array, that is, the light emitting element array (LPH1) 21, the light emitting element array (LPH2) 22, and the light emitting element array (LPH3) 23 I do.

  The light emitting element arrays 21, 22, and 23 are configured by arranging a plurality of light emitting elements such as LEDs (Light Emitting Diodes) in the main scanning direction.

  The data capture control unit 10 captures input image data from a host device (not shown) in units of lines, and this line data is stored in LPH1 line memories 11-1 and LPH2 line memories corresponding to the respective light emitting element arrays 21, 22, and 23. 11-2, divided into LPH3 line memory 11-3 and sequentially written.

  Here, the input image data is captured by the data capture control unit 10 as, for example, parallel 8-bit line data, and the parallel 8-bit line data is used for LPH 1 corresponding to each light emitting element array 21, 22, 23. Data, data for LPH2, and data for LPH3 are divided into three, and written to each address of the LPH1 line memory 11-1, the LPH2 line memory 11-2, and the LPH3 line memory 11-3 in 8-bit units. .

  When writing control to the LPH1 line memory 11-1, the LPH2 line memory 11-2, and the LPH3 line memory 11-3 by the data fetch control unit 10, as described in detail later, the pixel position in units of 8 bits. Adjustments are made.

  In FIG. 1, the LPH1 line memory 11-1, the LPH2 line memory 11-2, and the LPH3 line memory 11-3 are shown as separate blocks, but these three memories are different address areas of one memory. You may make it comprise using.

  The LPH 1 data transfer control unit 12 takes in the LPH 1 data written in the LPH 1 line memory 11-1 and performs control to transfer the LPH 1 data to the light emitting element array 21.

  When transferring the LPH1 data to the light emitting element array 21, the pixel position is adjusted in units of 1 bit, as will be described in detail later.

  In this embodiment, since the three light emitting element arrays 21, 22, and 23 are arranged at a predetermined distance from each other in the double scanning direction of the photosensitive member, this distance is corrected. In addition, delay control is performed to transfer the LPH2 data and the LPH3 data via the LPH2 SRAM (Static Random Access Memory) 15 and the LPH3 SRAM 16.

  That is, the LPH2 data SRAM transfer control unit 13 takes in the LPH2 data written in the LPH2 line memory 11-2 and transfers the LPH2 data to the LPH2 SRAM 15.

  The LPH2 SRAM 15 temporarily stores the LPH2 data transferred from the LPH2 data SRAM transfer control unit 13 for the delay control.

  The LPH2 data stored in the LPH2 SRAM 15 is taken into the LPH2 data take-in control unit 17 at the timing of driving the light-emitting element array 22, and is controlled by the LPH2 data transfer control unit 19 to the light-emitting element array 22. Transferred.

  In this embodiment, since the pixel positions of the light emitting element array 21 and the light emitting element array 23 are adjusted with the light emitting element array 22 as a reference, the LPH2 data transfer control unit 19 performs the LPH2 data transfer control. Does not perform pixel position adjustment in 1-bit units.

  Similarly, the LPH3 data SRAM transfer control unit 14 takes in the LPH3 data written in the LPH3 line memory 11-3 and transfers the LPH3 data to the LPH3 SRAM 16.

  The LPH3 SRAM 16 temporarily stores the LPH3 data transferred from the LPH3 data SRAM transfer control unit 14 for the delay control.

  The LPH3 data stored in the LPH3 SRAM 16 is taken into the LPH3 data take-in control unit 18 at a timing when the light-emitting element array 23 is driven, and is controlled by the LPH3 data transfer control unit 20 into the light-emitting element array 23. Transferred.

  When transferring the LPH3 data to the light emitting element array 23, the pixel position is adjusted in units of 1 bit as will be described in detail later.

  FIG. 2 is a diagram for explaining the adjustment control of the pixel position at the joint portion between the three light emitting element arrays 21, 22, and 23 in the image writing apparatus shown in FIG.

  In this embodiment, as shown in FIG. 2A, the light-emitting element array 22 is arranged with a distance H1 away from the light-emitting element array 21 with respect to the sub-scanning direction of the photoconductor 100, and the light-emitting element array. The light emitting element array 21 is spaced from the light emitting element array 21 by a distance H2, and an electrostatic latent image is written on the photoconductor 100 using the three light emitting element arrays 21, 22, and 23.

  The correction of the deviation (distance H1) in the sub-scanning direction of the light-emitting element array 22 with respect to the light-emitting element array 21 and the deviation (distance H2) in the sub-scanning direction of the light-emitting element array 23 with respect to the light-emitting element array 21 are corrected by LPH2 shown in FIG. This is performed by a configuration using the SRAM 15 for LPS and the SRAM 16 for LPH3.

  Here, each light emitting element array 21 is connected to the joint portion between the light emitting element array 21 and the light emitting element array 22 and the joint portion between the light emitting element array 22 and the light emitting element array 23 with respect to the main scanning direction of the photoconductor 100. , 22 and 23, when gaps or overlaps occur in the printable areas (indicated by cross-hatching in FIG. 2), image quality defects such as white stripes or black stripes occur in these areas.

  The occurrence of gaps or overlaps in the printable area in the main scanning direction occurs due to mechanical attachment errors of the light emitting element arrays 21, 22, 23, thermal expansion of the light emitting element arrays 21, 22, 23, and the like. .

  In FIG. 2B, a gap L1 (dot) is generated in the printable area at the joint portion between the light emitting element array 21 and the light emitting element array 22, and the light emitting element array 22 and the light emitting element array 23 are joined. In the eye portion, L2 (dots) are overlapped in accordance with the printable area.

  In this case, white stripes occur at the joint between the light emitting element array 21 and the light emitting element array 22, and black stripes occur at the joint between the light emitting element array 22 and the light emitting element array 23.

  Here, in this embodiment, since the printable area of the light emitting element array 21 and the light emitting element array 23 is adjusted with reference to the printable area of the light emitting element array 22, FIG. As shown, for the light emitting element array 21, the printable area is increased by the pixel (dot) corresponding to the shift L1 toward the light emitting element array 22, and for the light emitting element array 23, the printing is performed. The possible area is reduced toward the light emitting element array 22 by the amount of pixels (dots) corresponding to the deviation L2, and the gap at the joint portion between the light emitting element array 21 and the light emitting element array 22 and the light emitting element array 22 and the light emitting element array are reduced. Adjustment is performed so as to eliminate the overlap at the joint portion with 23.

  FIG. 3 is a diagram showing details of adjustment of a printable area at a joint portion between the light emitting element array 21 and the light emitting element array 22 shown in FIG.

As shown in FIG. 3A, it is assumed that a gap of L1 (dots) is generated in the printable area at the joint portion between the light emitting element array 21 and the light emitting element array 22. Here, this gap L1 (dot) is
L1 (dot) = a × 8 + b (dot)
Where a and b are integers and b <8
Suppose that

  In this case, in the image writing apparatus shown in FIG. 1, a × 8 (dot) is adjusted by the address control for writing to the LPH1 line memory 11-1 of the data acquisition control unit 10, and b (dot) is , Adjustment is made by transfer control of the data transfer control unit 12 for LPH1.

  For example, if L1 (dot) is 18 dots, 2 × 8 = 16 (dots) is controlled by the address of writing to the LPH1 line memory 11-1 in the data fetch control unit 10 and the two-address light emitting element array. The adjustment is performed by shifting 18-16 = 2 (dots) to the 2-dot light emitting element array 22 side by the transfer control in the data transfer control unit 12 for LPH1.

As shown in FIG. 4A, it is assumed that L2 (dots) overlap in the printable area in the joint portion between the light emitting element array 22 and the light emitting element array 23. Here, this overlap L2 (dot) is
L2 (dot) = c × 8 + d (dot)
Where c and d are integers, d <8
Suppose that

  In this case, in the image writing apparatus shown in FIG. 1, c × 8 (dot) is adjusted by address control for writing to the LPH3 line memory 11-3 of the data acquisition control unit 10, and d (dot) is The adjustment is performed by the transfer control of the data transfer control unit 20 for LPH3.

  For example, if L2 (dots) is 10 dots, 8 (dots) is transferred to the 2-address dot light-emitting element array 22 side by controlling the write address for the LPH3 line memory 11-3 in the data fetch control unit 10. The adjustment is performed by shifting 2 (dots) to the 2-dot light emitting element array 22 side by the transfer control in the data transfer control unit 20 for LPH3.

  FIG. 5 is a diagram showing the relationship between the paper 500 to be printed and the print area.

  The printable area by the light emitting element arrays 21, 22, and 23 is set wider than the print width of the paper 500.

  Therefore, the print area (shown by hatching in FIG. 5) by the light emitting element arrays 21, 22, and 23 is adjusted by shifting the image data transferred to the light emitting element arrays 21, 22, and 23 according to the edge of the paper 500. The

  This adjustment of the print area sequentially shifts the write addresses for the LPH1 line memory 11-1, the LPH2 line memory 11-2, and the LPH3 line memory 11-3 in the data fetch control unit 10 shown in FIG. This is performed in units of 8 dots.

  For example, as shown in FIG. 5, if the deviation between the printable area and the print area of the light-emitting element array 21 is L0 (dot), the printable area can be written by writing print data to the LPH1 line memory 11-1. The L0 / 8 address is shifted from the print data, and the print data overflowed from the printable area of the LPH1 line memory 11-1 is moved to the head of the LPH2 line memory 11-3 in units of 8 dots. The print data overflowed from the line memory 11-3 is performed by moving to the head of the LPH3 line memory 11-3 in units of 8 dots.

  The adjustment of the print area does not have a problem of image quality failure like the adjustment in the joint portion of the light emitting element arrays 21, 22, and 23, so there is no problem in the rough adjustment of 8 dots.

  6 to 8 are diagrams showing the address configurations of the LPH1 line memory 11-1, the LPH2 line memory 11-2, and the LPH2 line memory 11-3, respectively.

  6 to 8, for the LPH 1 after the adjustment processing in the unit of 8 dots at the joint portion described in FIG. 3 or FIG. 4 and the adjustment processing of the printing area in the unit of 8 dots shown in FIG. Data, data for LPH2, and data for LPH3 are shown.

  That is, FIG. 6 shows the address configuration of the LPH1 line memory 11-1. 8-bit LPH1 print data is written in the addresses p to q-1, and other areas (addresses) are written. White data is written.

  In FIG. 6, only the logical address for storing the print data for LPH1 is shown, and the address of the area for storing the white data is omitted.

  Similarly, FIG. 7 shows the address configuration of the LPH2 line memory 11-2. 8-bit LPH2 print data is written in the addresses q to r-1, and the other areas (addresses) are written. Is written with white data.

  FIG. 8 shows the address configuration of the LPH3 line memory 11-3, and 8-bit LPH2 print data is written in each of the addresses r to s-1.

  7 and 8 also show only LPH2 print data and LPH3 print data storage logical addresses.

  As shown in FIGS. 6 to 8, the LPH1 line memory 11-1, the LPH2 line memory 11-2, and the LPH2 line memory 11-3 have continuous logical addresses for print data. In the print area adjustment processing of FIG. 5, the print data overflowing from the printable area of the LPH1 line memory 11-1 is moved to the head of the LPH2 line memory 11-3 in units of 8 dots, and the LPH2 line memory 11 The print data overflowing from -3 can be moved to the head of the LPH3 line memory 11-3 in units of 8 dots.

  FIG. 9 is a diagram for explaining adjustment processing in units of 1 bit (dot) by the transfer control of the LPH1 data transfer control unit 12 shown in FIG.

  In FIG. 9, FIG. 9A shows a state in which adjustment in units of one dot is not performed by the transfer control of the data transfer control unit 12 for LPH1.

  In this case, the LPH1 data transfer control unit 12 sequentially specifies the addresses of the LPH1 line memory 11-1, thereby fetching the LPH1 data from the LPH1 line memory 11-1 in units of 8 bits, and sequentially forming the light emitting element array. Forward to 21.

  FIG. 9B shows a case where adjustment is performed on the side opposite to the one-dot light emitting element array 22 by the transfer control of the LPH 1 data transfer control unit 12.

  In this case, the LPH1 data transfer control unit 12 fetches the LPH1 data in units of 8 bits from the LPH1 line memory 11-1 by sequentially designating the address of the LPH1 line memory 11-1. The LPH1 data in 8-bit units is sequentially shifted by 1 bit to the side opposite to the light emitting element array 22 and transferred to the light emitting element array 21.

  FIG. 9C shows a case where adjustment is made to the two-dot light emitting element array 22 side by the transfer control of the data transfer control unit 12 for LPH1.

  In this case, the LPH1 data transfer control unit 12 fetches the LPH1 data in units of 8 bits from the LPH1 line memory 11-1 by sequentially designating the address of the LPH1 line memory 11-1. The LPH1 data in 8-bit units is sequentially shifted by 2 bits to the light emitting element array 22 side and transferred to the light emitting element array 21.

  Note that the adjustment processing in units of 1 bit (dots) by the transfer control of the LPH3 data transfer control unit 20 shown in FIG. 1 can be performed in the same manner as described above.

  FIG. 10 is a flowchart showing the adjustment processing of the data for LPH1, the data for LPH2, and the data for LPH3 transferred to the light emitting element arrays 21, 22, and 23 of the image writing apparatus shown in FIG.

  In FIG. 10, first, it is examined whether there is a deviation between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 (step 201). If there is a deviation between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 (YES in step 201), then it is checked whether the deviation is 8 bits (dots) or more ( Step 202).

  If the deviation between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 is 8 bits (dots) or more (YES in step 202), the data acquisition control unit 10 uses the LPH1. The shift between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 is adjusted in units of 8 bits by address control for writing to the line memory 11-1 (step 203).

  When the 8-bit unit adjustment in step 203 is completed, the process returns to step 202, and it is checked whether the deviation between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 is 8 bits (dots) or more.

  If it is determined that the deviation between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 is less than 8 bits (dot) (NO in step 202), the data transfer control unit for LPH1 The shift between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 is adjusted in units of 1 bit by the transfer control of 12 (step 204).

  When the one-bit unit adjustment in step 204 is completed, the process returns to step 201 to check whether there is a difference between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22.

  If it is determined that there is no deviation between the light emitting element array (LPH1) 21 and the light emitting element array (LPH2) 22 (NO in step 201), then the light emitting element array (LPH2) 22 and the light emitting element It is checked whether or not there is a deviation from the array (LPH3) 23 (step 205). Here, if there is a deviation between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23 (YES in step 205), then it is checked whether the deviation is 8 bits (dots) or more ( Step 206).

  If the deviation between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23 is 8 bits (dots) or more (YES in step 206), the data acquisition control unit 10 uses the LPH3. A shift between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23 is adjusted in units of 8 bits by address control of writing to the line memory 11-3 (step 207).

  When the 8-bit unit adjustment in step 207 is completed, the process returns to step 206 to check whether the deviation between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23 is 8 bits (dots) or more.

  If it is determined that the deviation between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23 is less than 8 bits (dots) (NO in step 206), the data transfer control unit for LPH3 The shift between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23 is adjusted in units of 1 bit by the 20 transfer control (step 208).

  When the one-bit unit adjustment in step 208 is completed, the process returns to step 205 to check whether there is a difference between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23.

  Here, if it is determined that there is no deviation between the light emitting element array (LPH2) 22 and the light emitting element array (LPH3) 23 (NO in step 205), the print area of the print 8-dot unit described in FIG. An adjustment process is performed (step 209), and this process ends.

  The 8-bit (dot) unit adjustment by the write address adjustment process and the 1-bit (dot) unit adjustment by the transfer control are performed by referring to the actual print result. The shift of the printable area at the joint portion between the light emitting element array 22 and the light emitting element array 22 and the shift of the printable area at the joint portion between the light emitting element array 22 and the light emitting element array 23 are electrically detected and automatically performed. It may be configured.

  The present invention can be applied to an image writing apparatus of an image forming apparatus such as an electrophotographic printer in which a plurality of light emitting element arrays are arranged in a staggered manner with respect to a photoreceptor. According to the present invention, the pixel position is coarsely adjusted, for example, in units of 8 dots by address control of a line memory for writing image data, and then fine adjustment is performed in units of 1 bit by transfer control of image data to the light emitting element array. Since it is configured, it is possible to perform correction with high accuracy at the joints of the light emitting element arrays, and it is possible to provide an image writing apparatus and method that can be configured at low cost and that are also suitable for high-speed transfer of image data. .

1 is a block diagram showing an embodiment of an image writing apparatus according to the present invention. . FIG. 2 is a diagram for explaining pixel position adjustment control at a joint portion between light emitting element arrays in the image writing apparatus shown in FIG. 1. It is a figure which shows the detail of adjustment of the printable area | region in the connection part of the light emitting element array 21 and the light emitting element array 22 which were shown in FIG. FIG. 3 is a diagram showing details of adjustment of a printable area at a joint portion between the light emitting element array 22 and the light emitting element array 23 shown in FIG. 2. It is a figure which shows the relationship between the paper 500 and the printing area | region to print. It is a figure which shows the address structure of the line memory 11-1 for LPH1. It is a figure which shows the address structure of the line memory 11-2 for LPH2. It is a figure which shows the address structure of the line memory 11-3 for LPH3. It is a figure explaining the adjustment process of 1 bit (dot) unit by the transfer control of the data transfer control part 12 for LPH1 shown in FIG. 4 is a flowchart showing adjustment processing of LPH1 data, LPH2 data, and LPH3 data transferred to the light emitting element arrays 21, 22, and 23 of the image writing apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Data acquisition control part 11-1 LPH1 line memory 11-2 LPH2 line memory 11-3 LPH3 line memory 12 LPH1 data transfer control part 13 LPH2 data SRAM transfer control part 14 LPH3 data SRAM transfer control part 15 SRAM for LPH2
16 SRAM for LPH3
17 LPH2 Data Acquisition Control Unit 18 LPH3 Data Acquisition Control Unit 19 LPH2 Data Transfer Control Unit 20 LPH2 Data Transfer Control Unit 21, 22, 23 Light Emitting Element Array (LPH)

Claims (5)

A plurality of light emitting element arrays in which light emitting elements are arranged in the main scanning operation direction are arranged in a staggered manner with respect to the photosensitive member, and image data is divided and transferred to the plurality of light emitting element arrays to thereby transfer the plurality of light emitting element arrays. In the image writing apparatus of the image forming apparatus, the light emitting element is caused to emit light corresponding to the image data, and an electrostatic latent image is written on the photosensitive member by light emission of the light emitting element.
Storage means for writing the image data in a predetermined pixel unit to each address corresponding to the light emitting element array;
Data transfer means for taking in the image data from the storage means by the addressing of the storage means and transferring them to the light emitting element array;
First adjustment means for adjusting image data to be written to the storage means by address control of the storage means in units of the predetermined pixels;
An image writing apparatus comprising: a second adjusting unit that adjusts image data to be transferred to the light emitting element array in units smaller than the predetermined pixel unit by transfer control of the data transfer unit. The light emitting element array is:
A predetermined distance away from the photoconductor in the sub-scanning direction;
The data transfer means includes
2. The image writing apparatus according to claim 1, further comprising image data delay means for correcting a displacement of each arrangement position of each light emitting element array in the sub-scanning direction. The first adjusting means and the second adjusting means are:
The pixel position of the image data transferred to each light emitting element array is adjusted so that the pixel position of the image data is continuous at the joint portion in the main scanning direction of the light emitting element array.
The image writing apparatus according to claim 1 or 2, wherein The first adjusting means and the second adjusting means are:
4. The image writing apparatus according to claim 1, wherein the image data to be transferred to another light emitting element array is adjusted based on one or more of the light emitting element arrays. 5. A plurality of light emitting element arrays in which light emitting elements are arranged in the main scanning operation direction are arranged in a staggered manner with respect to the photosensitive member, and image data is divided and transferred to the plurality of light emitting element arrays to thereby transfer the plurality of light emitting element arrays. In the image writing method of the image forming apparatus, the light emitting element is caused to emit light corresponding to the image data, and an electrostatic latent image is written on the photoconductor by light emission of the light emitting element.
Write the image data to each address of the storage means in predetermined pixel units,
The image data is fetched from the storage means by the specified address by the storage means and transferred to the light emitting element array by the data transfer means,
The image data to be written in the storage unit by the address control of the storage unit is adjusted by the first adjustment unit in the predetermined pixel unit, and
An image writing method comprising: adjusting image data to be transferred to the light emitting element array by transfer control of the data transfer unit in units smaller than the predetermined pixel unit by a second adjustment unit.

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