JP2009169151A - Line head and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a line head and an image forming apparatus with reduced cost by saving memory resource. <P>SOLUTION: A head controller 20 includes a line buffer 23, a data transfer control section 24, image memory 25, a video data control section 26, a writing address operation section 27, a registration-inclination compensating information storing section 28, a UART communication section 29, a curve-MLA (micro lens array) compensating information storing section 30 and an EEPROM communication section 31. Furthermore, an EEPROM 32 is installed to the line head 10. The writing address operation section 27 executes each process of a registration compensation position calculation, an inclination compensating value position calculation, a curve compensation value position calculation, and an MLA compensation value position calculation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a line head that saves memory resources and reduces costs, and an image forming apparatus using the line head.

  In general, an electrophotographic toner image forming unit includes a photosensitive member as an image bearing member having a photosensitive layer on an outer peripheral surface, a charging unit that uniformly charges the outer peripheral surface of the photosensitive member, and a uniform charging unit using the charging unit. An exposure unit that selectively exposes the outer peripheral surface charged to form an electrostatic latent image, and a toner as a developer is applied to the electrostatic latent image formed by the exposure unit to form a visible image ( Developing means for forming a toner image).

  As the exposure means, a technique using a line head provided with a light emitter array is known. In this line head, light emitting elements such as LEDs and organic EL elements are installed in a light emitter array. Further, the output light of the light emitting element is applied to the photoconductor through the imaging lens. As the optical magnification of the imaging lens, a positive lens (selfoc lens) and a negative lens (micro lens) are used. For example, Patent Document 1 describes an example in which a latent image is formed by irradiating a photosensitive drum with output light of a light emitting element arranged two-dimensionally in a light emitter array. The light emitting element is controlled by a drive circuit.

  In this type of image forming apparatus, the drive circuit as shown in the block diagram of FIG. 11 is used. In FIG. 11, reference numeral 80 denotes a main body controller (print controller) connected to the control unit 70 of the line head, and is provided with a memory 78. 75 is a control circuit, 76 is a drive circuit, 77 is a memory, and 61 is a light emitting element using an organic EL element. The organic EL element 61 is connected to the drive circuit 76. Pixel data formed by the main body controller 80 is stored in the memory 78. When an image is formed on the photoconductor, pixel data is read from the memory 78, transmitted to the control unit 70, and temporarily stored in the memory 77. The control circuit 75 reads the pixel data stored in the memory 77, forms a drive signal, and supplies it to each light emitting element 61 through the drive circuit 76.

JP 2004-209777 A

  In the image forming apparatus, the following processing is required for pixel data in order to improve image quality. (1) Correction of displacement of latent image formation caused by curvature of the line head itself produced during the production of the line head, (2) Correction of skew displacement caused when the line head is attached to the image forming apparatus, (3) Color image Color misregistration correction (registration correction) during formation. Further, when a microlens having a negative optical magnification is used as the imaging lens, (4) it is necessary to adjust the light emission timing of each of the light emitting elements arranged corresponding to the imaging lens.

  In the conventional configuration described with reference to FIG. 11, such correction and adjustment of pixel data are executed by the main body controller 80 and stored in the memory 78. The pixel data after executing the corrections and adjustments (1) to (4) have a large data amount, and the memory for storing the corrected pixel data obtained by correcting the original pixel data has a large memory capacity. I need it. Such corrected pixel data is transmitted to the line head and stored in the memory on the line head side. For this reason, each of the memory of the main body controller and the memory on the line head side requires a large memory capacity, and there is a problem that the cost increases.

  SUMMARY An advantage of some aspects of the invention is that it provides a line head that saves memory resources and reduces costs, and an image forming apparatus using the line head. .

The line head of the present invention that achieves the above object provides:
A substrate,
A plurality of light emitting elements arranged on the substrate in the axial direction of the photosensitive member and the rotating direction of the photosensitive member;
An imaging lens provided corresponding to the light emitting element;
Control means for driving the light emitting element;
Storage means for storing pixel data supplied to the light emitting element;
Have
In the control means,
First control means for correcting a positional deviation when a latent image is formed on the photosensitive member by the light emitting element, and a second correcting unit for correcting a positional deviation of the latent image forming position of the photosensitive member due to the imaging lens. Control means,
Provided,
Pixel data after correction processing by the first control unit and the second control unit is stored in the storage unit.

  The line head according to the present invention is characterized in that the first control unit corrects a deviation of a curved position that occurs when the line head is manufactured and a skew position that occurs when the main body of the line head is attached.

  In the line head of the present invention, the first control unit corrects a registration position shift that occurs when a latent image of a color image is formed on the photoconductor.

  In the line head according to the aspect of the invention, the second control unit may include a positional shift in the axial direction of the photosensitive member and the rotational direction of the photosensitive member when a microlens having a negative optical magnification is used as the imaging lens. It is characterized by correcting.

  The line head of the present invention is characterized in that the control means corrects each positional deviation with respect to the pixel data created by an external controller.

  The line head according to the present invention is characterized in that each positional deviation correction is performed by rearranging pixel data with respect to the axial direction of the photoconductor and the rotation direction of the photoconductor.

  An image forming apparatus according to the present invention is characterized in that a plurality of line heads according to any one of claims 1 to 6 are provided corresponding to each color and image formation of a plurality of colors is simultaneously performed on a photosensitive member. And

  According to another aspect of the present invention, there is provided an image forming apparatus comprising: a charging unit, a line head according to any one of claims 1 to 6; a developing unit; At least two or more image forming stations provided with units are provided, and image formation is performed in a tandem manner by passing a transfer medium through each station.

  FIG. 2 is a schematic explanatory diagram illustrating an example of the line head 10 according to the embodiment of the present invention. In FIG. 2, reference numeral 4 denotes an imaging lens using, for example, a microlens having a negative optical magnification. Reference numeral 2 denotes a light emitting element arranged at a position corresponding to the inside of the imaging lens 4 on the substrate. It is arranged in plural. Within one imaging lens 4, a light emitting element group 6 is constituted by light emitting elements arranged in the axial direction (X direction) of the photosensitive member and the rotating direction (Y direction) of the photosensitive member. A plurality of light emitting element groups 6 are arranged in the X and Y directions on the substrate. Similarly, a plurality of imaging lenses 4 are arranged in the axial direction of the photosensitive member, and a plurality of imaging lenses 4 are also arranged in the rotating direction of the photosensitive member.

  Thus, a plurality of imaging lenses 4 are arranged in the X direction and the Y direction to form imaging lens rows R, S, and T. The imaging lens row R is on the upstream side in the rotation direction (Y direction) of the photoconductor, and the imaging lens row T is on the downstream side in the rotation direction of the photoconductor. The imaging lens row S is the middle stage in the rotation direction of the photosensitive member. In this example, there are three imaging lens rows, that is, a multi-stage configuration with three stages. For convenience, the imaging lens 4 is numbered 1-27.

  In the example of FIG. 2, the imaging lens rows R, S, and T are arranged in the Y direction as described above, and the imaging lens rows R, S, and T have different arrangement positions in the X direction. It is supposed to be arranged. The imaging lens rows R, S, and T can also be viewed as light emitting element group rows. Here, in the light emitting element group row, a plurality of light emitting elements are arranged in the rotation direction of the photosensitive member, but one light emitting element is arranged in the rotation direction of the photosensitive member, and the light emitting elements are arranged on the photosensitive member. A plurality of arrangements in the axial direction are defined as light emitting element rows.

  FIG. 1 is a block diagram of a control unit in the embodiment of the present invention. In FIG. 1, a head controller 20, a print controller 21, and a mechanical controller 22 are provided as control means for the line head 10. The line head 10, the head controller 20, and the mechanical controller 22 are disposed in the printer engine 33.

  The head controller 20 includes a line buffer 23, a data transfer control unit 24, an image memory 25, a video (VIDEO) data control unit 26, a write address calculation unit 27, a registration / skew correction information storage unit 28, a UART communication unit 29, A curvature / MLA (micro lens array) correction information storage unit 30 and an EEPROM communication unit 31 are provided. The line head 10 is provided with an EEPROM 32. The write address calculation unit 27 executes registration correction position calculation, skew correction value position calculation, curvature correction value position calculation, and MLA correction value position calculation.

  As shown in FIG. 1, the print coat roller 21, the mechanical controller 22, and the head controller 20 are each physically separated and connected via a serial communication line. The printer controller 21 transmits raster data to the head controller 20. The raster data is first stored in the line buffer 23 in the head controller 20.

  The head controller 20 reads the curvature correction information and the MLA correction information stored in the EEPROM 32 of the line head 10 via the EEPROM communication unit 31 and temporarily stores them in the curvature / MLA correction information storage unit 30. Also, registration correction information and skew correction information are read from the mechanical controller 22 via the UART communication unit 29 and temporarily stored in the registration / skew correction information storage unit 28.

  The write address calculation unit 27 acquires the bending / MLA correction information and the registration / skew correction information from the bending / MLA correction information storage unit 30 and the registration / skew correction information storage unit 28, respectively, and stores them in the line buffer 23. The rearrangement of each pixel data of the raster data is executed. In this pixel data rearrangement process, the address position and bank position in the image memory 25 are calculated. Specifically, as described above, registration correction position calculation, skew correction value position calculation, curvature correction value position calculation, and MLA correction value position calculation are executed. As described above, the write address calculation unit 27 “the first control means for correcting the positional deviation when the latent image is formed on the photosensitive member by the light emitting element” and “the latent image of the photosensitive member caused by the imaging lens”. It functions as a “second control means for correcting the displacement of the formation position”.

  The write address calculation unit 27 performs such rearrangement of the pixel data and stores the raster data in the image memory 25. When a latent image is formed on the photosensitive member, the printer controller 21 transmits a print start signal to the VIDEO data control unit 26. The VIDEO data control unit 26 reads the raster data corrected as described above and stored in the image memory 25 and outputs the raster data to the line head 10. Each light emitting element arranged in the line head is turned on to form a latent image on the photosensitive member.

  In a line head using an MLA (Micro Lens Array) according to an embodiment of the present invention, a light emitting element and an imaging lens of the line head are arranged as shown in FIG. 2 in order to achieve high resolution. The example of FIG. 2 differs from the line head using an imaging lens having a positive optical magnification in the arrangement of light emitting elements. That is, when an imaging lens having a positive optical magnification is used, the imaging lens numbers are arranged as “1, 2, 3,...” From the upstream side in the Y direction. On the other hand, when an imaging lens having a negative optical magnification is used, as shown in FIG. 2, they are arranged as “1, 2, 3,...” From the upstream side in the Y direction.

  When the optical magnification of the imaging lens is negative, in order to form a correct latent image on the photoconductor with these light emitting elements, in addition to the skew correction, curvature correction, and resist correction as described above, It is necessary to correct the light emission timing of the light emitting element. For this reason, the memory capacity for storing the corrected pixel data increases and the cost increases. In the embodiment of the present invention, the image memory provided in the conventional print controller 21 and the line memory (image memory) provided in the head controller 20 are integrated, and the image memory 25 is arranged in the head controller 20. Yes. For this reason, memory resources can be saved and the cost can be reduced.

  In the conventional configuration, a request signal is output from the head controller 20 to the print controller 21 when a latent image is formed on the photosensitive member. Next, the print controller 21 performs signal processing on the image signal included in the image formation command to generate video data corresponding to the toner color, and transmits the video data to the head controller 20 in response to the request signal. In contrast, in the embodiment of the present invention shown in FIG. 1, the head controller 20 performs data processing (skew correction, curvature correction, registration correction, MLA correction) related to the configuration of the line head 10 for video data. ) And the lighting of the line head 10 is controlled based on the processed data. In this way, all processing related to lighting control of the line head is performed by the head controller 20. For this reason, since the print controller 21 only needs to receive raster data from the outside, it is possible to form an image with high versatility by using a common control means regardless of the configuration of the line head 10.

  FIG. 3 is an explanatory diagram showing an example of registration correction according to the embodiment of the present invention. Reference numeral 36 schematically indicates an appropriate image forming position of the photosensitive member. The appropriate image forming positions 36 are numbered 1 to 30 for convenience in the X direction (axial direction of the photosensitive member) described in FIG. 37 corresponds to the image of the registration position deviation in the first row in the Y direction (rotation direction of the photosensitive member) described in FIG. 2, and 38 corresponds to the image of registration position deviation in the second row. In the images 37 and 38 of the resist position deviation, a position deviation of 3 dots of the imaging spot occurs on the upstream side in the Y direction. Further, a positional deviation of 4 dots is generated in the head image in the X direction.

  Reference numeral 35 denotes a memory table, which indicates storage positions of pixel data (raster data) 39 and 40. Pixel data 39 corresponds to the image 37, and pixel data 40 corresponds to the image 38. As described above, in the images 37 and 38, the registration position deviation of 4 dots occurs in the X direction, and the registration position deviation of 3 dots occurs in the Y direction. Therefore, the write address calculation unit 27 rearranges the pixel data and stores it in the memory table 35.

  This rearrangement of pixel data is performed as follows. That is, “1” that is the leading position in the X direction of the proper image forming position 36 corresponds to the address number “8” of the memory table. Since the images 37 and 38 have a registration position shift of 4 dots in the X direction, the pixel data 39 and 40 are rearranged from the address numbers “8” to “37” in the memory table, and “11” to “40”. ”Is calculated. Further, there is a registration position shift upstream from an image forming position appropriate for 3 dots in the Y direction. Therefore, pixel data 39 is stored in Bank 3 and pixel data 40 is stored in Bank 4 after being delayed by 3 dots with respect to Bank 0, that is, rearranged downstream in the Y direction.

FIG. 4 is an explanatory diagram showing an example of skew correction according to the embodiment of the present invention. In this example, images 37a and 38a having a skew position shift to the right in the X direction with respect to the appropriate image forming position 36 are formed. It is assumed that the images 37a and 38a have steps (a), (b), and (c). The portions (a) of the images 37 a and 38 a overlap the proper image forming position 36. In the part (b), the skew position shift is generated by one dot from the proper image forming position 36 on the upstream side in the Y direction. In the portion (c), the skew position deviation is generated by two dots upstream from the proper image forming position 36 in the Y direction. In addition,
The images 37a and 38a have a skew position shift only in the Y direction and no skew position shift in the X direction.

  The memory table 35 stores the rearranged pixel data 39a and 40a. Since the portions (a) of the images 37a and 38a correspond to the proper image forming position 36, the address numbers “8” to “17”, Bank0, Stored in Bank1. The part (b) is delayed by one dot in the Y direction, and the pixel data is stored in the address numbers “18” to “27”, Bank 1 and Bank 2 of the memory table 35. The portion (c) is delayed by 2 dots in the Y direction, and the pixel data is stored in the address numbers “28” to “37”, Bank 2 and Bank 3 of the memory table 35.

  FIG. 5 is an explanatory diagram illustrating an example of curvature correction according to the embodiment of the present invention. In this example, the images 37b and 38b have the steps (a) to (f) with respect to the appropriate image forming position 36 due to the manufacturing error of the line head. That is, the images 37b and 38b are formed in a shape that swells upstream in the Y direction with respect to the appropriate image forming position 36 as a whole.

  The portions (a) and (f) of the images 37 a and 38 a overlap the proper image forming position 36. In the part (b), the curved position shift is generated by one dot from the proper image forming position 36 on the upstream side in the Y direction. In the portions (c) and (e), the curved position is shifted by 2 dots upstream from the proper image forming position 36 in the Y direction. In the portion (d), the curved position shift is generated by 3 dots upstream from the proper image forming position 36 in the Y direction. It should be noted that the images 37b and 38b have a curved position shift only in the Y direction and no curved position shift in the X direction.

  The memory table 35 stores the rearranged pixel data 39b and 40b. The portions (a) and (f) of the images 37b and 38b correspond to the proper image forming position 36. For this reason, the pixel data is stored in Bank 0 and Bank 1 with the address numbers “8” to “12” and “33” to “37” in the memory table 35 without rearranging the pixel data. The portion (b) is delayed by one dot in the Y direction, and the pixel data is stored in the address numbers “13” to “17”, Bank 1 and Bank 2 of the memory table 35. The portion (c) is delayed by 2 dots in the Y direction, and the pixel data is stored in the address numbers “18” to “22”, Bank 2 and Bank 3 of the memory table 35. The part (d) is delayed by 3 dots in the Y direction, and the pixel data is stored in the address numbers “23” to “27”, Bank 3 and Bank 4 of the memory table 35.

  FIG. 6 is an explanatory diagram illustrating an example of MLA correction according to the embodiment of the present invention. When a microlens having a negative optical magnification is used as the imaging lens, it is necessary to invert pixel data in the axial direction (X direction) of the photosensitive member and the rotating direction (Y direction) of the photosensitive member. Further, it is necessary to rearrange the pixel data in consideration of the pitch in the Y direction between the light emitting elements provided corresponding to one imaging lens and the pitch in the Y direction between the imaging lenses. As the photosensitive member rotates (moves in the Y direction), a latent image is formed by the output light of the light emitting elements. If the rearrangement is not performed, the image formation spot is displaced and the image quality is deteriorated.

  Next, an example of the pitch in the Y direction between the light emitting elements and the pitch in the Y direction between the imaging lenses will be described with reference to FIG. In FIG. 8, R, S, and T are imaging lens rows in the X direction as in FIG. 2, and 6a to 6c indicate light emitting element groups provided corresponding to the imaging lenses. In the light emitting element group 6a, three light emitting element rows k to n are formed in the Y direction. The light emitting element group 6b has three light emitting element rows q to r in the Y direction, and the light emitting element group 6c has three light emitting element rows su to u in the Y direction. Yes. Tb corresponds to a pitch (arrangement offset) between the light emitting element rows k and m, that is, a pitch in the Y direction between the light emitting element rows. Ta corresponds to a pitch (arrangement offset) between the imaging lens rows.

  In the example of FIG. 6, five light emitting elements 2 are arranged in the X direction and three rows in the Y direction on one imaging lens 4 in FIG. 2, and a light emitting element group is formed by 15 light emitting elements. Corresponding to For example, A in FIG. 6 is assumed to be an image formed by a light emitting element corresponding to the position of the imaging lens “1”, B in FIG. To do.

  With respect to the appropriate image forming position 36, the images 37c and 38c of the A portion are shifted by 5 dots in the X direction. In the Y direction, the image corresponding to the upstream side corresponds to the appropriate image forming position 36. The image corresponding to the middle stage in the Y direction is shifted by 4 dots in the Y direction from the proper image forming position 36. The image corresponding to the downstream side in the Y direction is shifted by 7 dots in the Y direction from the proper image forming position 36.

  The image on the upstream side of the B portion in the Y direction is displaced by 5 dots in the X direction from the proper image forming position 36. Further, it is 21 dots shifted from the proper image forming position 36 in the Y direction. The image in the first row upstream of the C portion in the Y direction is shifted by 5 dots in the X direction from the proper image forming position 36 and is shifted by 41 dots in the Y direction.

  FIG. 7 is an explanatory diagram showing an example of a memory table 35 that stores pixel data after rearrangement when a microlens as shown in FIG. 6 is used as an imaging lens. Since the pixel data in the first row on the upstream side in the Y direction of the portion A corresponds to the proper image forming position 36 in the Y direction, it is stored in Bank 0 without being rearranged. Further, since there is a shift of 5 dots in the X direction, the top pixel data in the X direction is stored at address number 3.

  The pixel data in the first row of the middle part in the Y direction of the portion A is stored in Bank 3 because it is shifted by 4 dots from the appropriate image forming position 36 in the Y direction. Further, since there is a shift of 5 dots in the X direction, the top pixel data in the X direction is stored in address number 2. The pixel data of the first row on the downstream side in the Y direction of the portion A is stored in Bank 6 because it is displaced by 7 dots with respect to the appropriate image forming position 36 in the Y direction. Further, since there is a shift of 5 dots in the X direction, the top pixel data in the X direction is stored at address number 1.

Similarly, the pixel data in the portions B and C are rearranged by calculating the address number and the Bank position, and stored in a predetermined position in the memory table 35. In the embodiment of the present invention, since such MLA correction is performed, it is possible to reduce memory resources. As described with reference to FIG. 8, when the pitch between the light emitting elements (arrangement offset) is Tb and the pitch between the imaging lenses (arrangement offset) is Ta, in the conventional MLA correction,
A line memory of {Tb × (number of light emitting element stages−1) + Ta × (number of imaging lens stages−1) +1} is required.

  In the example of FIG. 8, since the number of light emitting element stages is 3 and the number of imaging lens stages is 3, 2Tb + 2Ta + 1 line memory is required. However, in the embodiment of the present invention, the write address calculation unit of FIG. 27, the pixel data of the MLA correction is rearranged, and the result is stored in the image memory 25, so that many conventional line memories are unnecessary.

  FIG. 9 is an explanatory diagram showing an embodiment of the present invention. FIG. 9A shows pixel data 36x stored in the memory table 35 when rearrangement is not performed. The pixel data 36x corresponds to pixel data for forming an image at an appropriate position on the photoconductor. FIG. 9B shows an example in which pixel data 39x rearranged by registration correction, curvature correction, skew correction, and MLA correction of the line head is stored in the memory table 35.

  In the embodiment of the present invention, a tandem color printer that exposes four photoconductors with four line heads, simultaneously forms four color images, and transfers them onto one endless intermediate transfer belt (intermediate transfer medium). The target is a line head used in (image forming apparatus). FIG. 10 is a longitudinal side view showing an example of a tandem image forming apparatus using an organic EL element as a light emitting element. This image forming apparatus includes four light emitter arrays (line heads) 101K, 101C, 101M, and 101Y having the same configuration and four corresponding photosensitive drums (image carriers) 41K and 41C having the same configuration. , 41M and 41Y, respectively, and is configured as a tandem image forming apparatus.

  As shown in FIG. 10, this image forming apparatus is provided with a drive roller 51, a driven roller 52, and a tension roller 53. The tension roller 53 applies tension to the image forming apparatus and stretches it in the direction indicated by the arrow (counterclockwise). ) Is circulated to the intermediate transfer belt (intermediate transfer medium) 50. Photosensitive members 41K, 41C, 41M, and 41Y having photosensitive layers are arranged on the outer peripheral surface as four image carriers arranged at predetermined intervals with respect to the intermediate transfer belt 50.

  K, C, M, and Y added after the reference sign mean black, cyan, magenta, and yellow, respectively, and indicate that the photoconductors are black, cyan, magenta, and yellow, respectively. The same applies to other members. The photoreceptors 41K, 41C, 41M, and 41Y are rotationally driven in the direction indicated by the arrow (clockwise) in synchronization with the driving of the intermediate transfer belt 50. Around each photoconductor 41 (K, C, M, Y), charging means (corona charger) 42 (K) for uniformly charging the outer peripheral surface of the photoconductor 41 (K, C, M, Y), respectively. , C, M, Y) and the outer peripheral surface uniformly charged by the charging means 42 (K, C, M, Y) are synchronized with the rotation of the photoconductor 41 (K, C, M, Y). Thus, the above-described light emitter array (line head) 101 (K, C, M, Y) of the present invention for sequentially scanning the line is provided.

  Further, a developing device 44 that applies toner as a developer to the electrostatic latent image formed by the light emitter array (line head) 101 (K, C, M, Y) to form a visible image (toner image). (K, C, M, Y) and primary transfer as transfer means for sequentially transferring the toner image developed by the developing device 44 (K, C, M, Y) to the intermediate transfer belt 50 as a primary transfer target. A roller 45 (K, C, M, Y) and a cleaning device 46 (K, C) as a cleaning means for removing toner remaining on the surface of the photoconductor 41 (K, C, M, Y) after being transferred. C, M, Y).

  Here, in each light emitter array (line head) 101 (K, C, M, Y), the array direction of the light emitter array exposure head 101 (K, C, M, Y) is the photosensitive drum 41 (K, C). , M, Y) along the bus. Then, the emission energy peak wavelength of each light emitter array (line head) 101 (K, C, M, Y) and the sensitivity peak wavelength of the photoconductor 41 (K, C, M, Y) are substantially matched. Is set.

  The developing device 44 (K, C, M, Y) uses, for example, a non-magnetic one-component toner as a developer, and the one-component developer is conveyed to the developing roller by a supply roller, for example, and adhered to the developing roller surface. The film thickness of the developed developer is regulated by a regulating blade, and the developing roller is brought into contact with or increased in thickness by the photosensitive body 41 (K, C, M, Y), whereby the photosensitive body 41 (K, C, M, Y). The toner is developed as a toner image by attaching a developer according to the potential level.

  The black, cyan, magenta, and yellow toner images formed by the four-color single-color toner image forming station are intermediated by the primary transfer bias applied to the primary transfer roller 45 (K, C, M, Y). The toner image, which is sequentially primary transferred onto the transfer belt 50 and sequentially superposed on the intermediate transfer belt 50 to become a full color, is secondarily transferred to a recording medium P such as paper by a secondary transfer roller 66, and serves as a fixing unit. The toner is fixed on the recording medium P by passing through the fixing roller pair 61, and is discharged onto a paper discharge tray 68 formed in the upper part of the apparatus by a paper discharge roller pair 62.

  In FIG. 10, reference numeral 63 denotes a paper feed cassette in which a large number of recording media P are stacked and held, 64 denotes a pickup roller for feeding the recording media P one by one from the paper feed cassette 63, and 67 denotes a secondary transfer roller. Reference numeral 69 denotes a gate roller pair that regulates the supply timing of the recording medium P to the secondary transfer portion 66, and 69 denotes a cleaning blade as a cleaning means for removing toner remaining on the surface of the intermediate transfer belt 50 after the secondary transfer. .

  As described above, the line head and the image forming apparatus of the present invention have been described based on the principle and the embodiments, but the present invention is not limited to these embodiments and can be variously modified.

It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. 1 is a schematic cross-sectional view showing an overall configuration of an embodiment of an image forming apparatus using an electrophotographic process of the present invention. It is a block diagram which shows a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Light emitting element, 4 ... Imaging lens, 6 ... Light emitting element group, 10 ... Line head, 20 ... Head controller, 21 ... Printer controller, 22 ... Mechanical controller , 23... Line buffer, 25... Image memory, 27... Write address calculation unit, 28... Registration / skew correction information storage unit, 30. (K, C, M, Y) ... photosensitive drum (image carrier), 42 (K, C, M, Y) ... charging means (corona charger), 44 (K, C, M, Y) ... developing device, 45 (K, C, M, Y) ... primary transfer roller, 50 ... intermediate transfer belt, 66 ... secondary transfer roller, 101K, 101C, 101M, 101Y ..Light emitter array (line head)

Claims (8)

A substrate,
A plurality of light emitting elements arranged on the substrate in the axial direction of the photosensitive member and the rotating direction of the photosensitive member;
An imaging lens provided corresponding to the light emitting element;
Control means for driving the light emitting element;
Storage means for storing pixel data supplied to the light emitting element;
Have
In the control means,
First control means for correcting a positional deviation when a latent image is formed on the photosensitive member by the light emitting element, and a second correcting unit for correcting a positional deviation of the latent image forming position of the photosensitive member due to the imaging lens. Control means,
Provided,
A line head, wherein pixel data after correction processing by the first control means and the second control means is stored in the storage means. 2. The line head according to claim 1, wherein the first control unit corrects a curved position shift that occurs when the line head is manufactured and a skew position shift that occurs when the main body of the line head is attached. 3. 2. The line head according to claim 1, wherein the first control unit corrects a registration position shift that occurs when a latent image of a color image is formed on the photosensitive member. The second control unit corrects a positional deviation in the axial direction of the photosensitive member and the rotation direction of the photosensitive member when a microlens having a negative optical magnification is used as the imaging lens. The line head according to any one of claims 1 to 3. 5. The line head according to claim 1, wherein the control unit corrects each displacement with respect to the pixel data created by an external controller. 6. 6. The line according to claim 1, wherein each of the misregistration corrections is performed by rearranging pixel data with respect to an axial direction of the photoconductor and a rotation direction of the photoconductor. head. The image forming apparatus according to claim 1, wherein a plurality of line heads are provided corresponding to each color, and image formation of a plurality of colors is simultaneously performed on a photosensitive member. At least two image forming stations, each of which includes a charging unit, a line head according to any one of claims 1 to 6, a developing unit, and a transfer unit, are arranged around the photosensitive member. One or more image forming apparatuses are provided, and an image forming apparatus performs image formation by a tandem method by passing a transfer medium through each station.

Images