JP2008030203A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can smoothly and rationally carry out image formation, and to provide an image forming method. <P>SOLUTION: Image data supplied to each light emitting element of a plurality of light emitting element arrays in which a plurality of the light emitting elements arranged in a main scanning direction are arranged in the main scanning direction and a sub-scanning direction is stored in a memory table 10 while being reversed in the main scanning direction in position of an imaging spot formed on an image carrier. At the same time, the image data is divided to groups (A-C) by dividing a plurality of the light emitting element arrays arranged in the sub-scanning direction for every sub-scanning direction. The image data of Aa is read out, the image data of Ba is read out after T1, and the image data of Ca is read out after T1+T2. Imaging spots arranged in one array in the main scanning direction are thus formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an image forming method capable of smoothly and rationally forming an image when a lens having a negative optical magnification is used.

  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 a tandem type image forming apparatus for forming a color image, a plurality (for example, four) of toner image forming means as described above are arranged on the intermediate transfer belt. The toner image on the photosensitive member by the single color toner image forming unit is sequentially transferred to the intermediate transfer belt, and the toner images of a plurality of colors (for example, yellow, cyan, magenta, and black (black)) are superimposed on the intermediate transfer belt. There is an intermediate transfer belt type that obtains a color image on an intermediate transfer belt.

  In a tandem color image forming apparatus (printer), a technique using a light emitter array as the exposure means (line head) is known. For example, Patent Document 1 describes an example in which a latent image is formed by magnifying output light of a light emitting element arranged two-dimensionally in a light emitter array with a single lens and irradiating the photosensitive drum. .

JP 2001-63139 A

  In the light emitter array described in Patent Document 1, as shown in FIG. 1 of Patent Document 1, the single lens 14 reverses the output light of the light emitting member 1 in the main scanning direction, and the photosensitive drum 15. Irradiating. That is, the single lens 14 has a negative optical magnification. Therefore, unlike SLA (Selfoc lens array), the optical magnification is positive and the output light of the light emitting element is different from the case where the image carrier is irradiated in the optical axis direction. When a light emitter array as described in Patent Document 1 is used as a line head, in order to perform image formation smoothly, how to read out image data stored in a memory and perform predetermined printing. Alternatively, a specific memory configuration and image data reading sequence are required. However, Patent Document 1 has a problem that it does not describe this.

  The present invention has been made in view of such problems of the prior art, and an object thereof is to provide an image forming apparatus capable of smoothly and rationally forming an image when a lens having a negative optical magnification is used. An object is to provide an image forming method.

The image forming apparatus of the present invention that achieves the above object provides:
An image forming apparatus that simultaneously performs image formation of a plurality of colors on an image carrier using a plurality of line heads corresponding to each color, and a plurality of colors on the image carrier using a plurality of line heads corresponding to each color An image forming apparatus that simultaneously performs image formation,
A plurality of light emitting element arrays in which a plurality of light emitting elements are arranged in the main scanning direction are arranged in the main scanning direction and the sub scanning direction, and the light emitting element arrays arranged in the sub scanning direction are divided for each sub scanning direction. A grouped light emitter array (line head), a microlens array in which each light emitting element array is associated with a lens having a negative optical magnification, and a storage means for storing image data to be supplied to each light emitting element are provided. ,
The storage means has a memory table in which the image data is stored in accordance with the grouping, and the image data is stored on the image carrier by the light emitting elements. Is reversed in the main scanning direction, and the image data of the one group is read out to form an imaging spot on the image carrier, and after a predetermined timing, the image data of another group is sequentially applied to the image carrier. Control means for controlling to form an imaging spot is provided. According to such a configuration, when the light emitting element array is made to correspond to a lens having a negative optical magnification and a plurality of light emitting element arrays and lens sets are provided in the main scanning direction and the sub-scanning direction, the microlens is formed. Can be performed smoothly. The memory table can cope with a case where the optical magnification is negative like a microlens and the position of the light emitting element and the position of the imaging spot on the image carrier are reversed in the main scanning direction and the sub scanning direction.

    In the image forming apparatus of the present invention, the memory table includes a plurality of horizontal columns for storing image data for each light emitting element arranged in the main scanning direction of the light emitter array, and sub-scanning of the image carrier. A plurality of vertical columns for storing image data for each light emitting element are formed in a matrix so as to form a plurality of imaging spots in the direction, and each group of light emitting element rows divided in the sub-scanning direction is formed. Further, the image data of the horizontal column and the vertical column is allocated by a predetermined number. According to such a configuration, when the optical magnification as in the micro lens is negative and the position of the light emitting element and the position of the imaging spot on the image carrier are reversed in the main scanning direction and the sub scanning direction, the image data Can be read smoothly.

  The image forming apparatus of the present invention is characterized in that the control means forms imaging spots arranged in a line in the main scanning direction of the image carrier. According to such a configuration, rational image formation can be performed.

  In the image forming apparatus of the present invention, the predetermined timing is determined based on a moving speed of the image carrier and a distance in the sub-scanning direction of the light emitting elements between the light emitting element rows. . According to such a configuration, image formation can be smoothly performed using existing parameters.

  The image forming apparatus of the present invention is characterized in that the predetermined timing is finely adjusted by the control means. According to such a configuration, it is possible to prevent deterioration in image quality.

  In the image forming apparatus of the present invention, the light emitting element is an organic EL element. Since the organic EL element does not need to reduce the diameter of the light emitting part, the light power of the light emitting part can be increased. For this reason, it is possible to use an organic EL material having a low luminous efficiency.

  The image forming apparatus of the present invention is characterized in that the lenses are arranged in a plurality of rows in the sub-scanning direction while shifting the head position in the main scanning direction, and the light emitting element rows are associated with each lens. According to such a configuration, an image can be smoothly formed in an image forming apparatus in which lenses, for example, microlens arrays are arranged in a staggered manner.

    The image forming apparatus of the present invention is provided with at least two or more image forming stations in which the image forming units of the line head, the developing unit, and the transfer unit described above are arranged, and the transfer medium is provided for each of the transfer media. By passing through the station, image formation is performed by a tandem method. According to such a configuration, in a tandem color image forming apparatus, it is possible to smoothly perform image formation when a lens array having a negative optical magnification is used.

  In addition, the image forming apparatus of the present invention includes an intermediate transfer medium. According to this configuration, in an image forming apparatus having an intermediate transfer medium, it is possible to smoothly perform image formation when a lens array having a negative academic magnification is used.

The image forming method of the present invention is an image forming method for simultaneously forming a plurality of color images using a plurality of line heads corresponding to each color, and forming a plurality of color images using a plurality of line heads corresponding to each color. Is an image forming method for simultaneously performing on the image carrier,
A plurality of light emitting element arrays in which a plurality of light emitting elements are arranged in the main scanning direction are provided in the sub scanning direction, a lens having a negative optical magnification is associated with each light emitting element array, and image data supplied to each light emitting element is Providing a storage means for storing;
The image data is stored in the memory table of the storage means for each line of the imaging spot formed on the image carrier, and the position of the imaging spot formed on the image carrier by each light emitting element is the main scanning direction. And a step of inputting the light-emitting element rows arranged in a plurality of rows in the sub-scanning direction so as to be supplied to the respective light-emitting elements divided into groups in the sub-scanning direction, and 1 The step of reading out image data of one group and forming an imaging spot on the image carrier, and the step of forming an imaging spot on the image carrier sequentially from another group of image data after a predetermined timing. The imaging spots are formed in a line in the main scanning direction of the image carrier. According to such a configuration, image formation when a lens having a negative optical magnification is used can be quickly and accurately performed using the memory table having the above configuration. The memory table can cope with a special situation where the optical magnification is negative like a micro lens and the position of the light emitting element and the position of the imaging spot on the image carrier are reversed in the main scanning direction and the sub scanning direction. The image data can also be rationally read out.

  FIG. 3 is a schematic explanatory view showing an example of a light emitter array used as a line head in the embodiment of the present invention. In FIG. 3, the light emitter array 1 is provided with light emitting element rows 3a to 3c in which a plurality of light emitting elements 2 are arranged in the main scanning direction. In the example of FIG. 3, each light emitting element row 3 a to 3 c has four light emitting elements arranged in the main scanning direction.

  The light emitting element arrays 3a to 3c are arranged corresponding to the micro lenses 5a to 5c. A plurality of microlenses 5 a to 5 c are provided in the main scanning direction and the sub-scanning direction of the light emitter array 1 to form a microlens array (MLA) 6. The MLA 6 is arranged with the leading position in the main scanning direction shifted in the sub-scanning direction. Such an arrangement of MLA can correspond to the case where the light emitting elements 1 are provided in a staggered manner in the light emitter array 1. In the example of FIG. 3, three rows of MLA 6 are arranged in the sub-scanning direction. However, for convenience of explanation, the light emitting element rows 3 a to 3 c corresponding to the respective positions of the three rows of MLA 6 in the sub-scanning direction are group A , Group B and group C.

  As the light emitting element 2, for example, an organic EL element is used. Since the organic EL element does not need to reduce the diameter of the light emitting part, the light power of the light emitting part can be increased. For this reason, it is possible to use an organic EL material having a low luminous efficiency. The output light of each light emitting element is inverted in the main scanning direction by the microlens 5 and irradiated to the image carrier.

  FIG. 4 is an explanatory diagram showing the position of the imaging spot when the exposure surface of the image carrier (photosensitive member) is irradiated with the output light of each light emitting element 2 through the microlens 5 in the configuration of FIG. In FIG. 4, the microlenses 5a to 5c have a negative optical magnification. When the output light of each light emitting element is irradiated, the imaging spots formed at the imaging positions 7a to 7c on the image carrier are mainly The position is reversed in the scanning direction.

  In FIG. 4, S is the moving speed of the image carrier, d1 is the distance in the sub scanning direction between the light emitting elements in the light emitting element rows 3a and 3b, and d2 is the distance in the sub scanning direction between the light emitting elements in the light emitting element rows 3b and 3c. , T1 and T2 are moving times of the image carrier, and correspond to a memory address reading timing which will be described later.

  In the embodiment of the present invention, as shown in FIG. 3, when a plurality of light emitting element rows 3 a to 3 c are arranged in the light emitter array 1 at positions corresponding to the micro lenses 5 a to 5 c in the sub-scanning direction, An imaging spot can be formed in a line in the main scanning direction of the image carrier. Here, in order to form the imaging spots in a line in the main scanning direction of the image carrier, it is necessary to adjust the timing at which the light emitting elements of each light emitting element array in FIG. 3 emit light.

  FIG. 1 is an explanatory diagram according to an embodiment of the present invention. FIG. 1 shows a line buffer memory table for storing image data. A pixel number (corresponding to the number of the light emitting element in FIG. 2) is set on the horizontal axis of the memory table 10, and a line number (imaging spot line formed on the image carrier) is set on the vertical axis. That is, the memory table 10 includes a plurality of horizontal columns in which image data corresponding to each light emitting element arranged in the main scanning direction of the light emitter array and a plurality of lines in the sub scanning direction of the image carrier. A plurality of vertical columns in which image data is stored are formed in a matrix so that spots are formed.

  The basic operation of the image formation on the image carrier according to the present invention will be described. Of the image data stored in the table of the line buffer memory, data corresponding to group A is read from the memory table and transmitted to the line head to cause the corresponding light emitting element to emit light. Next, after the image carrier moves in the sub-scanning direction after a predetermined time T1, the image data corresponding to the group A and the main scanning direction is read out and the image data corresponding to the group B is read out to the line head. Transmitting and causing the corresponding light emitting element to emit light.

  In the same manner, from the operation for the light emitting elements of group B, after the image carrier moves in the sub-scanning direction after T2 hours, it becomes the same line in the main scanning direction as groups A and B and corresponds to group C. Image data is read out and transmitted to the line head, and the corresponding light emitting element is caused to emit light. By such control, the imaging spots formed by the light emitting element rows of group A and the imaging spots formed by the light emitting element rows of groups B and C are at the same position in the main scanning direction. An image spot can be formed.

  Here, in the plurality of horizontal columns of the memory table 10, pixel numbers 1 to 4 are assigned to group A, pixel numbers 5 to 8 are assigned to group B, and pixel numbers 9 to 12 are assigned to image data of light emitting elements of group C. In the plurality of vertical columns, line 2 to line 4 are assigned to group C, line 12 to line 14 are assigned to group B, and line 22 to line 24 are assigned to image data of light emitting elements of group A. For example, when the time of the image data reading timings T1 and T2 corresponds to 10 lines in the memory table of the line buffer, the image forming procedure is as follows. The image data Aa corresponding to the group A on the 22nd line of the memory table 10 is read, and the image data Ba corresponding to the group B on the 12th line is read after T1 time. Further, after (T1 + T2) time, the image data Ca corresponding to the group C of the second line is read and transmitted to the line head.

Next, the image data Ab, Bb, and Cb for the next line of the address read last time are read and transmitted to the line head. Next, the next image data Ac, Bc, Cc is read out by one line and transmitted to the line head.
By repeating such a process 20 times, 2 to 22 lines of imaging spots are formed in a line on the image carrier (photoconductor).
The above image forming process is performed for one page. FIG. 2 is an explanatory view showing an example of the imaging spot 8 formed by one line in the main scanning direction by such processing.

  Here, the image data Aa corresponds to pixel numbers 1 to 4, the image data Ba corresponds to pixel numbers 5 to 8, and the image data Ca corresponds to pixel numbers 9 to 12, respectively. Image data Ab and Ac correspond to pixel numbers 1 to 4, image data Bb and Bc correspond to pixel numbers 5 to 8, and image data Cb and Cc correspond to pixel numbers 9 to 12, respectively. That is, as shown in FIG. 3, when the light emitting element rows of groups A to C are arranged in the light emitter array 1, image data for the light emitting elements of group A are stored in a plurality of lines in pixel numbers 1 to 4. To do. Similarly, pixel numbers 5 to 8 store image data for light emitting elements of group B in a plurality of lines, and pixel numbers 9 to 12 store image data for light emitting elements of group C in a plurality of lines.

  The memory table 10 of FIG. 1 stores image data by dividing one line of memory addresses into groups A to C. As described above, the memory table according to the embodiment of the present invention includes a horizontal column for storing image data for each light emitting element arranged in the main scanning direction of the light emitter array, and a plurality of lines in the sub scanning direction of the image carrier. Are formed in vertical columns for storing image data for each light emitting element. The memory table 10 is assigned image data in a horizontal column and a vertical column for each group of light emitting element columns divided in the sub-scanning direction.

  In the memory table 10, as shown in FIG. 3, a plurality of groups A to C are formed in the light emitter array 1 in the sub-scanning direction, and a plurality of light-emitting element columns in each group are arranged in the main scanning direction. In the configuration, image data is stored so that imaging spots arranged in a line in the main scanning direction of the image carrier are formed. The formation of the imaging spot on the image carrier is realized by appropriately setting the readout timing of the image data in consideration of the distance d of the light emitting element in the sub scanning direction and the moving speed S of the image carrier. Is possible. As described above, in the embodiment of the present invention, a single microlens is associated with a light emitting element array in which a plurality of light emitting elements are arranged in the main scanning direction. When a plurality of sets of columns are arranged in each of the main scanning direction and the sub-scanning direction, a contrivance is added to the configuration of the memory table that stores the image data supplied to each light emitting element. The arrangement of the image data at the memory address is set in consideration of the fact that the imaging spot on the image carrier by the light emitting element is inverted in the main scanning direction.

  In addition, the number of light emitting elements corresponding to a single microlens has been described in the example of the light emitting element array arranged in the main scanning direction so far, but the number of light emitting elements in the main scanning direction in one light emitting element array is 2. The number can be any number as described above. The number of light emitting element arrays in the sub-scanning direction of the light emitter array, and therefore the number of microlens arrays in the sub-scanning direction has been described in the example of three lines. However, the number of arrays in the sub-scanning direction is an arbitrary number of 2 or more. It can be.

  FIG. 5 is an explanatory diagram of the embodiment of the present invention. FIG. 5 shows an imaging spot 9 on the image carrier when the timing adjustment of the microlens array is poor. As shown in FIG. 5, T1 is not stabilized due to fluctuations in the speed S of the image carrier, variations in the distance d of the light emitting element in the sub-scanning direction, variations in optical adjustment, and the like. Even if it is designed to correspond, it varies slightly.

For this reason, the imaging spot formation position in the first row and the imaging spot formation position in the second row are shifted, and the shape of the imaging spot that should be aligned in one row is distorted as shown in FIG. That is, the image quality is degraded. Therefore, a slight misalignment is corrected by adopting a configuration in which T1 can be finely adjusted. T1 can be obtained as follows.
T1 = | (d × β) / S |
Here, each parameter is as follows.
D: Distance of the light emitting element in the sub-scanning direction
S: Moving speed of image plane (image carrier) β: Lens magnification

  FIG. 6 is a block diagram illustrating an example of an embodiment of the present invention. In FIG. 6, the control device 20 has a line buffer memory 23 for storing image data, and a read address control circuit 21 for determining a read address in the line buffer based on the Hreq signal (horizontal line read request signal). . The image data at the memory addresses in the groups A to C described with reference to FIG.

The read timing T1 calculation circuit 26 calculates a read timing time T1 based on the image carrier (photosensitive member) speed S detection means 25 and the position data 27 of the distance d of the light emitting element in the sub-scanning direction. The read timing T2 calculation circuit 28 calculates the read timing time T2 based on the image carrier (photosensitive member) speed S detection means 25 and the position data 29 of the distance d in the sub-scanning direction of the light emitting element.
Based on the read enable signal of the read enable control circuit 22 that generates the read enable signal based on the Hreq signal, the A group data transmission module 30 reads the A group data of FIG. 1 from the memory, and the line head (light emitter array). 1 to transmit the light emitting element.

The B group data transmission module 31 reads the B group data of FIG. 1 from the memory after T1 from the read enable of the group A, and transmits it to the line head 1 to cause the light emitting elements to emit light.
Furthermore, the C group data transmission module 32 reads the C group data of FIG. 1 from the memory after T1 + T2 from the read enable of the group A, and transmits it to the line head 1 to cause the light emitting elements to emit light.

  FIG. 7 is a flowchart showing the processing procedure of the present invention. Next, this flowchart will be described. The processing is started (S1), and the Hreq signal is counted (S2). Next, a read line in the memory is determined based on the count value of the Hreq signal (S3). Subsequently, a read enable is created based on the Hreq signal (S4). When reading is enabled, image data corresponding to group A is transmitted to the reading line head (S5).

Based on the image carrier (photoconductor) speed S and the distance d in the sub-scanning direction of the light emitting element, the read timing time T1 is calculated (S6). After T1 from the read enable, the image data corresponding to the group B is transmitted to the read line head (S7). Next, a read timing time T1 is calculated based on the image carrier (photoconductor) speed S and the distance d in the sub-scanning direction of the light emitting element (S8). Subsequently, image data corresponding to the group C is transmitted to the read line head after T1 + T2 from the read enable (S9).
Next, it is determined whether or not the count value of the Hreq signal is for one page (S10), and if the determination result is Yes, the process ends (S11). If the determination result is No, the processing returns to (S2).

  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. 8 is a vertical 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. 8, this image forming apparatus is provided with a driving 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 direction). ) 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. 8, 63 is a paper feed cassette in which a large number of recording media P are stacked and held, 64 is a pickup roller for feeding the recording media P from the paper feed cassette 63 one by one, and 65 is a secondary transfer roller. A pair of gate rollers for defining the supply timing of the recording medium P to the secondary transfer portion 66, a secondary transfer roller 66 as a secondary transfer means for forming a secondary transfer portion with the intermediate transfer belt 50, 67 Is 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 image forming apparatus and the image forming method 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 a block diagram which shows embodiment of this invention. It is a flowchart which shows the process sequence 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.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light emitter array, 2 ... Light emitting element, 3 ... Light emitting element row, 5 ... Micro lens, 6 ... Micro lens array (MLA), 7 ... Imaging position, 8 , 9 ... Imaging spot, 10 ... Table, 20 ... Control device, 41 (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, .... Intermediate transfer belt, 66 ... secondary transfer roller, 101K, 101C, 101M, 101Y ... light emitter array (line head)

Claims (10)

An image forming apparatus that simultaneously forms a plurality of colors on an image carrier using a plurality of line heads corresponding to each color,
A plurality of light emitting element arrays in which a plurality of light emitting elements are arranged in the main scanning direction are arranged in the main scanning direction and the sub scanning direction, and the light emitting element arrays arranged in the sub scanning direction are divided for each sub scanning direction. Grouped luminous element arrays (line heads);
A microlens array in which each light emitting element row is associated with a lens having a negative optical magnification, and a storage unit that stores image data to be supplied to each light emitting element;
The storage means has a memory table in which the image data is stored in accordance with the grouping, and the image data is stored on the image carrier by the light emitting elements. Is reversed in the main scanning direction, and the image data of the one group is read out to form an imaging spot on the image carrier, and after a predetermined timing, the image data of another group is sequentially applied to the image carrier. An image forming apparatus comprising a control means for controlling to form an imaging spot. The memory table forms a plurality of horizontal columns storing image data for each light emitting element arranged in the main scanning direction of the light emitter array, and a plurality of lines of imaging spots in the sub scanning direction of the image carrier. As described above, a plurality of vertical columns for storing image data for each light-emitting element are formed in a matrix, and a predetermined number of the horizontal columns and a plurality of columns for the light-emitting element columns divided in the sub-scanning direction. 2. The image forming apparatus according to claim 1, wherein image data in a vertical column is assigned. The image forming apparatus according to claim 1, wherein the control unit forms an imaging spot arranged in a line in a main scanning direction of the image carrier. 4. The predetermined timing is determined based on a moving speed of the image carrier and a distance in the sub-scanning direction of the light emitting elements between the light emitting element rows. An image forming apparatus according to claim 1. The image forming apparatus according to claim 4, wherein the predetermined timing is finely adjusted by the control unit. The image forming apparatus according to claim 1, wherein the light emitting element is an organic EL element. 7. The lens according to claim 1, wherein the lenses are arranged in a plurality of rows in the sub-scanning direction by shifting a head position in the main scanning direction, and the light-emitting element rows are associated with each lens. The image forming apparatus described in 1. 8. At least two image forming stations in which image forming units including a charging unit, a line head according to claim 1, a developing unit, and a transfer unit are arranged around an image carrier. An image forming apparatus provided as described above, wherein the transfer medium passes through each station and forms an image by a tandem method. The image forming apparatus according to claim 8, further comprising an intermediate transfer member. An image forming method for simultaneously performing image formation of a plurality of colors on an image carrier using a plurality of line heads corresponding to each color,
A plurality of light emitting element arrays in which a plurality of light emitting elements are arranged in the main scanning direction are provided in the sub scanning direction, a lens having a negative optical magnification is associated with each light emitting element array, and image data supplied to each light emitting element is Providing a storage means for storing;
The image data is stored in the memory table of the storage means for each line of the imaging spot formed on the image carrier, and the position of the imaging spot formed on the image carrier by each light emitting element is the main scanning direction. And a step of inputting the light-emitting element rows arranged in a plurality of rows in the sub-scanning direction so as to be supplied to the respective light-emitting elements divided into groups in the sub-scanning direction, and 1 The step of reading out image data of one group and forming an imaging spot on the image carrier, and the step of forming an imaging spot on the image carrier sequentially from another group of image data after a predetermined timing. An image forming method comprising forming imaging spots arranged in a line in a main scanning direction of the image carrier.

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