JP2008036983A - Image forming apparatus and image formation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image formation method whereby image formation can be smoothly and rationally carried out. <P>SOLUTION: In an illuminant array 1, light emitting elements (8, 6, 4 and 2) of even numbers are arranged at the upstream side (first array) in a moving direction of an image carrier, and light emitting elements (7, 5, 3 and 1) of odd numbers are arranged at the downstream side (second array) of the same. The light emitting elements of the upstream side of the image carrier 41 are made to emit light first, thereby forming imaging spots to the image carrier. Then, the light emitting elements of odd numbers of the downstream side of the image carrier 41 are made to emit light after the lapse of a predetermined timing, thereby forming imaging spots to the image carrier. The imaging spots by the light emitting elements of the odd numbers are formed at a position of 8 in the same array in a main scanning direction. <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,
Image data to be supplied to each light emitting element by associating a single lens having a negative optical magnification with a light emitter block in which a plurality of light emitting element arrays arranged in the main scanning direction are arranged in the sub scanning direction. Storing means for storing
The storage means stores the image data so that the position of the imaging spot formed on the image carrier by each light emitting element is reversed in the main scanning direction, and the even number of the light emitting element rows. A memory table that stores the first image data supplied to the light emitting elements and the second image data supplied to the odd-numbered light emitting elements;
The first image data or the second image data is read to form an imaging spot on the image carrier, and after a predetermined timing, the image data is inverted on the image carrier by the other image data in the sub-scanning direction. Control means for controlling to form an imaging spot is provided. According to such a configuration, image formation when a single lens having a negative optical magnification is used and a plurality of issue element rows are arranged in the sub-scanning direction is performed using the memory table having the above-described configuration. It can be done smoothly. Further, the memory table can cope with a special situation in which the optical magnification is minus 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 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 storage unit stores the image data in an area where the position of the imaging spot formed on the image carrier by the light emitting elements is reversed in the main scanning direction. It is characterized by. According to such a configuration, it is possible to smoothly perform the process of forming the imaging spot at a position reversed in the main scanning direction of the image carrier.

  In the image forming apparatus of the present invention, the light emitter blocks are arranged in a plurality of rows in the main scanning direction and the sub-scanning direction, a single lens having a negative optical magnification is associated with each light emitter block, and the sub-scanning is performed. The light emitter blocks arranged in a plurality of rows in the direction are divided into groups in each sub-scanning direction, and the storage means has a memory table that stores the image data divided in correspondence with the grouping, In the image data, the position of the imaging spot formed on the image carrier by each light emitting element is reversed in the main scanning direction, and the image data of the one group is read out on the image carrier in the sub scanning direction. After forming a reversed imaging spot with, control to sequentially form a reversed imaging spot in the sub-scanning direction on the image carrier based on the image data of another group after a predetermined timing. And wherein the Rukoto. According to such a configuration, an imaging spot can be smoothly formed on the image carrier at a position reversed in the main scanning direction and the sub-scanning direction.

  In the image forming apparatus of the present invention, image data is stored in the memory table so that a plurality of lines of imaging spots are formed in the sub-scanning direction of the image carrier. According to such a configuration, it is possible to cope with a case where a plurality of lines of images are formed on the image carrier.

  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 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 the tandem color image forming apparatus, it is possible to smoothly perform image formation when a single lens 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 single lens having a negative academic magnification is used.

The image forming method of the present invention is an image forming method in which image formation of a plurality of colors is simultaneously performed on an image carrier using a plurality of line heads corresponding to each color,
Image data to be supplied to each light emitting element by associating a single lens having a negative optical magnification with a light emitter block in which a plurality of light emitting element arrays arranged in the main scanning direction are arranged in the sub scanning direction. Storing means for storing
In the memory table of the storage means, for each line of the imaging spot formed on the image carrier, the image data is the first row on the upstream side of the image carrier and the second row on the downstream side, Dividing and inputting the first image data supplied to the first light emitting element of the light emitting element row and the second image data supplied to the second light emitting element;
Determining whether to read the image data of any of the lines;
Reading the first image data or the second image data corresponding to the determined line from the memory table to form an imaging spot on the image carrier;
After a predetermined timing, the other image data is read from the memory table and an imaging spot that is inverted in the sub-scanning direction is formed on the image carrier, and is arranged in a line in the main scanning direction of the image carrier. The image forming spot is formed in a line. According to such a configuration, image formation when a single lens having a negative optical magnification is used can be performed quickly and accurately by using the memory table having the above configuration. Further, the memory table can cope with a special situation in which the optical magnification is minus like a micro lens, the position of the light emitting element and the position of the imaging spot on the image carrier are reversed in the sub-scanning direction, and the image data is also Reasonable reading can be performed.

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 emitter blocks each having a plurality of light emitting element rows arranged in the main scanning direction are arranged in the main scanning direction and the sub scanning direction, and the optical magnification of each of the light emitter blocks is negative. Storage means for storing image data to be supplied to each of the light emitting elements, the light emitting blocks arranged in a plurality of rows in the sub scanning direction being divided and grouped for each sub scanning direction. Provided,
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 to be supplied to each of the grouped light emitting elements, and a step of reading out image data of one group to form an imaging spot on the image carrier. Forming an imaging spot on the image carrier sequentially from another group of image data after a predetermined timing, and forming the imaging spots aligned in the main scanning direction of the image carrier. Features. According to such a configuration, when a lens array having a negative optical magnification is used, the image carrier is quickly and accurately positioned at a position opposite to the position of the light emitting element in the main scanning direction and the sub scanning direction. Image formation can be performed by arithmetic processing.

  FIG. 15 is a schematic explanatory view showing an example of a light emitter array used as a line head. In FIG. 15, in the light emitter array 1, a light emitter block 4 is formed by providing a plurality of light emitting element rows 3 in which a plurality of light emitting elements 2 are arranged in the main scanning direction in the sub scanning direction. In the example of FIG. 15, the light emitter block 4 forms two light emitting element rows 3 in which four light emitting elements 2 are arranged in the main scanning direction in the sub scanning direction. Light-emitting element rows by odd-numbered light-emitting elements are arranged in the first row in the sub-scanning direction (upstream in the moving direction of the image carrier), and even numbers are arranged in the second row (downstream in the moving direction of the image carrier). The light emitting element row | line | column by the light emitting element of a number is arranged.

  The light emitter block 4 is disposed corresponding to the lens 35. As the lens 35, for example, a positive magnification SL (Selfoc lens) is used. Further, 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.

  FIG. 16 is an explanatory diagram showing the imaging position 7 in the sub-scanning direction of the image carrier with the configuration of FIG. In FIG. 16, the light emitting elements 2a and 2b are arranged at different positions in the sub-scanning direction. The output light of each light emitting element 2a, 2b is irradiated to the imaging positions 7a, 7b corresponding to each light emitting element 2a, 2b of the image carrier 41 through the lens 35. Here, it is assumed that the image carrier 41 rotates in the direction of arrow R. For this reason, the imaging positions 7a and 7b on the image carrier by the light emitting elements 2a and 2b are formed by being shifted by the time T.

  FIG. 17 is an explanatory diagram showing the image forming position 7s of the image carrier 41 in the main scanning direction in the configuration of FIG. In FIG. 17, the image carrier 41 rotates in the arrow R direction. The imaging positions 7s of the light emitting element rows 3 arranged in the main scanning direction of the light emitter array 1 on the image carrier 41 by the respective light emitting elements are simultaneously formed in the same row in the main scanning direction.

  FIG. 18 is an explanatory diagram showing the position of the imaging spot formed on the image carrier 41 when a positive magnification lens is used in the optical system. The number of the imaging spot in FIG. 18 corresponds to the number of the light emitting element in FIG. As shown in FIG. 15, when the light emitting element rows are arranged in two rows in the sub-scanning direction, the image spot 8p is formed on the image carrier 41 at a position shifted in the sub-scanning direction. Will be.

  For this reason, as shown in FIG. 20, in order to form the imaging spots 8x at positions 1 to 8 arranged in a line in the main scanning direction, the read timing of the image data stored in the memory table is set. Need to control. FIG. 19 is an explanatory diagram showing an example of the memory table 10 of the line buffer in which image data is stored. In FIG. 19, the memory table 10 has pixel numbers (corresponding to the light emitting element numbers in FIG. 15) on the horizontal axis and column numbers (imaging spot lines formed on the image carrier) on the vertical axis. is doing.

Of the image data stored in the memory table 10 of the line buffer,
First, image data (1, 3, 5, 7) corresponding to the light emitting elements in the first column is read, and the light emitting elements emit light. Next, after T time, the image data (2, 4, 6, 8) corresponding to the light emitting elements in the second column stored in the memory address is read and emitted. The output light of the light emitting element passes through the lens and is irradiated to the image carrier. In this way, the first row of image formation spots on the image carrier is formed in the same row as the second row of image formation spots in the main scanning direction.

  When the lens 5 in FIG. 15 is replaced with a lens 5 having a negative optical magnification, such as a microlens, instead of the lens 35 having a positive optical magnification, the output light of each light emitting element is in the sub-scanning direction and the main scanning direction. Is inverted and irradiated to the image carrier. FIG. 21 is an explanatory diagram of an example in which the imaging spot reversed in the sub-scanning direction is formed on the image carrier. In FIG. 21, the position where the imaging spot of the image carrier 41 is formed in the light emitting element of ○ 1 (shown in this way for conversion reasons) arranged upstream in the sub-scanning direction in FIG. 15. 7 is formed on the downstream side in the sub-scanning direction. Further, the position 7 where the imaging spot is formed on the image carrier of the light emitting element ◯ 2 arranged on the downstream side in the sub-scanning direction is formed on the upstream side in the sub-scanning direction.

  In FIG. 21, S is the moving speed of the image carrier, d is the distance in the sub-scanning direction between the light emitting elements, T1 is the moving time of the image carrier, and corresponds to the memory address read timing described later. FIG. 22 is a diagram corresponding to FIG. 17, and the output light of each light emitting element is inverted and irradiated in the main scanning direction by the image carrier 41, and the imaging spot is formed at the position 7.

  As described above, when the lens 5 having a negative optical magnification is used, the output light of each light emitting element is inverted in the sub-scanning direction and the main scanning direction and irradiated to the image carrier. Accordingly, the correspondence between the imaging spots formed on the image carrier and the light emitting elements is as shown in the explanatory diagram of FIG. That is, the positional relationship of the imaging spots in FIG. 23 corresponding to the arrangement of the light emitting elements in FIG. 15 is formed in a state where both are reversed in the main scanning direction and the sub-scanning direction.

FIG. 24 shows a lens 5 with a negative optical magnification corresponding to the case where the timing for forming an imaging spot in the sub-scanning direction is adjusted, as described in the case where the lens 35 with a positive optical magnification in FIG. 19 is used. It is explanatory drawing at the time of using. That is, first, the image data (1, 3, 5, 7) corresponding to the first row of light emitting elements on the upstream side with respect to the moving direction of the image carrier is read, and the light emitting elements are caused to emit light. Next, after time T, the image data (2, 4, 6, 8) corresponding to the light emitting elements in the second column on the downstream side with respect to the moving direction of the image carrier stored in the memory address is read and emitted. Let As shown in FIG. 24, the imaging spots 8r are formed so as to be reversed in the main scanning direction and the sub-scanning direction, and are not formed in the same row in the main scanning direction.

  FIG. 25 is an explanatory diagram illustrating an example in which the read timing of image data is changed. In FIG. 25, the second image data (2, 4, 6, 8) corresponding to the light emitting elements in the second column in FIG. 15 is read first, and the light emitting elements are caused to emit light. Next, the first image data (1, 3, 5, 7) corresponding to the light emitting elements in the first column is read and emitted. FIG. 26 is an explanatory diagram showing the position of the imaging spot when image data is read out as shown in FIG. As shown in FIG. 26, the same image forming spot is formed on the image carrier in the main scanning direction, but the image forming spot is formed at a position reversed in the main scanning direction in relation to the light emitting element. Is done. There may be no problem even if the image formed on the recording medium is not inverted in the main scanning direction, such as a horizontal line. Such a case can be dealt with by forming the imaging spot by inverting the image data in the sub-scanning direction by the reading control of the memory table as shown in FIG.

  In this way, when drawing a horizontal line or the like on a recording medium, image data reading control from the memory table can be handled only by reversal in the sub-scanning direction. However, when drawing a natural image, a character, a vertical line, or the like, the image data read control needs to be reversed in the main scanning direction. In another embodiment of the present invention, image data reading control is performed by inverting the main scanning direction and the sub-scanning direction.

  FIG. 4 is an explanatory diagram showing a correspondence relationship between the light emitter array 1 and the lens 5 having a negative optical magnification according to the embodiment of the present invention. In the example of FIG. 4, the position of the light emitting element is reversed in the main scanning direction and the sub-scanning direction from the explanatory diagram shown in FIG. That is, in the configuration of FIG. 4, even-numbered light emitting elements (8, 6, 4, 2) are arranged on the upstream side (first row) in the moving direction of the image carrier, and the downstream side (second row). ) Are arranged with odd-numbered light emitting elements (7, 5, 3, 1). In addition, a light emitting element having a large number is arranged on the head side in the main scanning direction.

  1 to 3 are perspective views of an embodiment of the present invention. As shown in FIG. 2, the imaging spot 8a of the image carrier 41 corresponding to the odd-numbered light emitting elements 2 arranged on the downstream side of the image carrier 41 is at a position inverted in the main scanning direction. It is formed. R is the moving direction of the image carrier 41. As shown in FIG. 3, the imaging spot 8b of the image carrier 41 corresponding to the even-numbered light emitting elements 2 arranged on the upstream side (first row) of the image carrier 41 is in the sub-scanning direction. It is formed at the position on the downstream side reversed by. However, in the main scanning direction, the positions of the imaging spots from the head side correspond to the light emitting elements 1 to 8 in order. Therefore, in this example, it can be seen that the imaging spots can be formed in the same row in the main scanning direction by adjusting the timing of forming the imaging spots in the sub-scanning direction of the image carrier.

  FIG. 5 is an explanatory diagram showing an example of the memory table 10 of the line buffer in which image data is stored. The memory table 10 in FIG. 5 is stored with being inverted in the main scanning direction with respect to the light emitting element numbers in FIG. In FIG. 5, among the image data stored in the memory table 10 of the line buffer, first image data (1, 3, 5, 5) corresponding to the light emitting elements on the upstream side (first column) of the image carrier 41 first. 7) to read out the light emitting element. Next, after T time, the second image data (2, 4, 6, 8) corresponding to the light emitting elements on the downstream side (second column) stored in the memory address is read out to emit light. . In this way, as shown by the position 8 in FIG. 6, the first row of imaging spots on the image carrier is formed in the same row as the second row of imaging spots in the main scanning direction.

  FIG. 1 is a perspective view conceptually showing an example in which image data is read out at the timing of FIG. 5 to form an imaging spot. As described with reference to FIG. 5, the light emitting element on the upstream side (first row) of the image carrier 41 is first caused to emit light, thereby forming an imaging spot on the image carrier. Next, after a predetermined timing T has elapsed, the odd-numbered light emitting elements on the downstream side (second row) of the image carrier 41 are caused to emit light, thereby forming an imaging spot on the image carrier. At this time, the imaging spot formed by the odd-numbered light emitting elements is not formed at the position 8a described in FIG. 2, but is formed at the position 8 in the same row in the main scanning direction as shown in FIG. It will be.

  FIG. 7 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. 7, in the light emitter array 1, a light emitter block 4 is formed by providing a plurality of light emitting element rows 3 in which a plurality of light emitting elements 2 are arranged in the main scanning direction in the sub scanning direction. In the example of FIG. 6, the light emitter block 4 forms two light emitting element rows 3 in which four light emitting elements 2 are arranged in the main scanning direction in the sub scanning direction. A large number of the light emitter blocks 4 are arranged in the light emitter array 1, and each light emitter block 4 is arranged corresponding to the microlens 5.

  A plurality of microlenses 5 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. 7, three rows of MLA 6 are arranged in the sub-scanning direction. However, for convenience of explanation, the unit blocks 4 corresponding to the respective positions of the three rows of MLA 6 in the sub-scanning direction are group A and group B. And group C.

  As described above, when a plurality of light emitters are arranged in a lens having a negative optical magnification and the lenses are arranged in a plurality of rows in the sub-scanning direction, one row is arranged in the main scanning direction of the image carrier. In order to form the imaging spots arranged side by side, the following image data control is required. (1) Inversion in the sub-scanning direction, (2) Inversion in the main scanning direction, (3) Adjustment of light emission timing of a plurality of light emitting elements in the lens, and (4) Adjustment of light emission timing of light emitting elements between groups.

  FIG. 8 is an explanatory view showing an imaging position when the exposure surface of the image carrier is irradiated through the microlens 5 with the output light of each light emitting element 2 in the configuration of FIG. In FIG. 8, as described with reference to FIG. 7, the light emitter array 1 has unit blocks 4 divided into group A, group B, and group C. The light-emitting element rows of the unit blocks 4 of group A, group B, and group C are divided into the upstream side (first row) and the downstream side (second row) of the image carrier, and the even-numbered light-emitting elements in the first row And odd-numbered light emitting elements are assigned to the second column.

  For group A, by operating each light emitting element as described with reference to FIG. 1, an image spot is formed on the image carrier at positions reversed in the main scanning direction and the sub-scanning direction. In this manner, imaging spots are formed on the image carrier in the order of 1 to 8 in the same row in the main scanning direction. Thereafter, the image carrier is moved in the sub-scanning direction for a predetermined time, and the processing of group B is executed in the same manner. Further, by moving the image carrier in the sub-scanning direction for a predetermined time and executing the process of group C, the result is based on the input image data in the order of 1 to 24... In the same column in the main scanning direction. An image spot is formed.

FIG. 9 is an explanatory diagram showing a state of forming an imaging spot in the sub-scanning direction in FIG. S is the moving speed of the image carrier 41, d1 is the distance between the first and second light emitting elements in group A, and d2 is the second light emitting element in group A and the second light emission in group B. The element spacing, d3 is the distance between the light emitting elements in the second row of group B and the light emitting elements in the second row of group C, and T1 is the light emitting element in the first row after the light emission of the light emitting elements in the second row of group A. Time to do,
T2 is the time required for the imaging position of the second row of light emitting elements in group A to move to the imaging position of the second row of light emitting elements in group B, and T3 is the imaging position of the second row of light emitting elements in group A. This is the time for moving to the imaging position of the light emitting elements in the second row of group C.

T1 can be obtained as follows. T2 and T3 can also be obtained by replacing d1 with d2 and d3.
T1 = | (d1 × β) / S |
Here, each parameter is as follows.
d: Distance in the sub-scanning direction of the light emitting element
S: Moving speed of image plane (image carrier) β: Lens magnification

  In FIG. 9, the light emitting elements in the second row of group B are caused to emit light after time T2 of the time when the light emitting elements in the second row of group A emit light. Furthermore, the light emitting elements in the second row of group C are caused to emit light after T2 to T3 hours. The first row of light emitting elements in each group emits light after T1 time after the second row of light emitting elements emits light. By performing such processing, as shown in FIG. 8, the imaging spots formed by the light emitters arranged two-dimensionally on the light emitter array 1 can be formed in a line on the image carrier. It becomes possible. FIG. 10 is an explanatory diagram showing an example in which the imaging spot is formed by reversing in the main scanning direction of the image carrier when a plurality of lenses 5 are arranged.

  FIG. 11 is a block diagram illustrating an example of an embodiment of the present invention. In FIG. 11, the control device 20 receives image data from the controller 30, performs the following processing, and transmits the image data to the light emitter array 1. The base pointer generator 21 generates a base point (base stage) based on Hreq (horizontal direction request signal) and Vreq (vertical direction request signal), and the base data is written to the write address generator 22 of the MLA control memory and the MLA control. The data is transmitted to the memory read address generator 27. The base point (base stage) will be described later. The write address generator 22 of the MLA control memory generates a write address and transmits it to the MLA control line buffer memory 23.

  The read address generator 27 of the MLA control memory receives the base data of the base pointer generator 21 and outputs an inversion LUT 24 (inversion in the main scanning direction), an intra-group timing LUT 25 (inversion in the sub-scanning direction), and an inter-group timing LUT 26. The read address is determined with reference to the MLA control line buffer memory 23. The MLA control line buffer memory 23 transmits the image data to the light emitter array 1.

  FIG. 12 is a flowchart showing a processing procedure when forming an image corresponding to MLA. In FIG. 12, processing is started (S11), and image data is written to the base stage of the line buffer (S12). Here, the “base stage” is one of the banks 1 to 49... In the memory table of FIG. 13, and the bank 47 is displayed as the base stage in FIG. Therefore, image data is written in the bank 47. Next, the base pointer counter is incremented. The base stage shifts to the bank 48 (S13).

  Image data is written to the base stage 48 (S14). Based on the base position, the read address in the main scanning direction is determined with reference to the inversion LUT (S15). Subsequently, the read address in the sub-scanning direction is determined by referring to the timing LUT based on the base position (S16). Here, the readout address in the sub-scanning direction is determined for both the intra-group timing LUT 25 and the inter-group LUT 26 shown in FIG. Image data is read according to the determined address (S17). It is determined whether or not Read / Write for one page has been completed (S18). If the determination result is YES, the line buffer memory is cleared (S19), and the process is terminated (S20). If a determination result is No, it will return to the process of S13 and will repeat the loop process of S13-S18.

  13 and 14 are explanatory diagrams according to the embodiment of the present invention, and show a table of a line buffer memory that stores image data. A pixel number (corresponding to the light emitting element number in FIG. 8) is set on the horizontal axis of the memory table 10, and an imaging spot line formed on the image carrier is set on the vertical axis.

  FIG. 13 will be described. Image data for one line is stored in the base stage (line 47 in this example) indicated by hatching (see FIG. 14). Next, the image data (odd number) in the second column of group A in line 46 on the upper stage of the base stage (line 47) is read out. In this example, image data is stored in the image carrier so that an imaging spot is formed at a position reversed in the main scanning direction with respect to the position of the light emitting element in FIG.

  Subsequently, as described with reference to FIG. 9, the image data (odd number) of the second column of group B stored in the line 26 of the memory table T2 hours after the reading of the image data of the second column of group A. Is read. In addition, the image data (odd number) of the second column of group C stored in the line 6 of the memory table is read after T3 time from the reading of the image data of the second column of group B. The image data (even number) in the first column corresponding to the time T1 is read out from the image data in the second column of each group. For example, in group A, image data (even number) stored in line 45 of the memory table is read. The image data read in this way is transmitted to the light emitter array.

  FIG. 14 shows an example in which the base stage is shifted down by one from FIG. 13 and the line 48 is the base stage. Image data (odd number) in the second column of group A on the upper stage of the base stage (line 48) is read. Subsequently, as described with reference to FIG. 9, the image data (odd number) of the second column of group B stored in the line 27 of the memory table T2 hours after the reading of the image data of the second column of group A. Is read. In addition, the image data (odd number) of the second column of group C stored in the line 7 of the memory table is read after T3 time from the reading of the image data of the second column of group B. The image data (even number) in the first column corresponding to the time T1 is read out from the image data in the second column of each group. For example, in group A, image data (even number) stored in the line 46 of the memory table is read. The image data read in this way is transmitted to the light emitter array.

  By performing the above operations for one page, (1) inversion in the sub-scanning direction, (2) inversion in the main scanning direction, (3) adjustment of light emission timings of a plurality of light-emitting elements in the lens, and (4) between groups The light emission timing of the light emitting element is adjusted, and a latent image in which one line of image data is accurately arranged in a line on the photosensitive member can be formed.

  In the embodiment of the present invention, as described in the above embodiment, the address when reading out the image data in the table of the line buffer memory corresponds to the light emitting element and the image data as described in FIGS. Let Then, after the image data of the second column of each group is read out and lighted for T1 time, the image data of the first column is read and lighted, and the adjustments (1) to (4) as described above are performed. Can be controlled.

  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. 27 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. 27, 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). ) 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. 27, 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 65 denotes 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 the 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 a perspective view which shows embodiment of this invention. It is a perspective view which shows embodiment of this invention. It is a perspective view 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 a block diagram which shows embodiment of this invention. It is a flowchart which shows the process sequence 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. 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.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light emitter array, 2 ... Light emitting element, 3 ... Light emitting element row, 4 ... Light emitter block, 5 ... Micro lens, 6 ... Micro lens array, 7 ... Imaging position 8, 9 ... Imaging spot, 10 ... Memory 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, 50 ... 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,
Image data to be supplied to each light emitting element by associating a single lens having a negative optical magnification with a light emitter block in which a plurality of light emitting element arrays arranged in the main scanning direction are arranged in the sub scanning direction. Storing means for storing
The storage means supplies the image data to the first light emitting element of the light emitting element array when the upstream side in the moving direction of the image carrier is the first line and the downstream side is the second line. A memory table divided and stored in first image data and second image data supplied to the light emitting elements in the second column;
The image data is read out from the first image data or the second image data to form an imaging spot on the image carrier, and after a predetermined timing, the other image data is sub-scanned on the image carrier. An image forming apparatus comprising control means for controlling to form an imaging spot that is reversed in a direction. The image forming apparatus according to claim 1, wherein the control unit performs control so as to form imaging spots arranged in a line in a main scanning direction of the image carrier. The said storage means stores the said image data in the area | region where the position of the imaging spot formed on an image carrier by each said light emitting element is reversed in a main scanning direction, The said image data is characterized by the above-mentioned. Item 3. The image forming apparatus according to Item 2. A plurality of rows of light emitter blocks arranged in the main scanning direction and the sub-scanning direction, each light emitter block corresponding to a single lens having a negative optical magnification, and a plurality of rows of light emitter blocks arranged in the sub-scanning direction Are divided into groups for each sub-scanning direction, and the storage means has a memory table that stores the image data divided according to the grouping, and the image data is divided by the light emitting elements. The position of the imaging spot formed on the image carrier is reversed in the main scanning direction, and the image data of the one group is read to form an imaging spot reversed on the image carrier in the sub scanning direction. From the above, control is performed so that an imaging spot that is inverted in the sub-scanning direction is sequentially formed on the image carrier by image data of another group after a predetermined timing. The image forming apparatus according. The image data is stored in the memory table so that a plurality of lines of image spots are formed in the sub-scanning direction of the image carrier. The image forming apparatus described. The image forming apparatus according to claim 1, wherein the light emitting element is an organic EL element. 7. At least two image forming stations in which image forming units including 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 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 7, 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,
Image data to be supplied to each light emitting element by associating a single lens having a negative optical magnification with a light emitter block in which a plurality of light emitting element arrays arranged in the main scanning direction are arranged in the sub scanning direction. Storing means for storing
In the memory table of the storage means, for each line of the imaging spot formed on the image carrier, the image data is the first row on the upstream side of the image carrier and the second row on the downstream side, Dividing and inputting the first image data supplied to the first light emitting element of the light emitting element row and the second image data supplied to the second light emitting element;
Determining whether to read the image data of any of the lines;
Reading the first image data or the second image data corresponding to the determined line from the memory table to form an imaging spot on the image carrier;
After the predetermined timing, the other image data is read from the memory table and an imaging spot that is inverted in the sub-scanning direction is formed on the image carrier, and is arranged in a line in the main scanning direction of the image carrier. An image forming method characterized by forming image forming spots arranged side by side. 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 emitter blocks each having a plurality of light emitting element rows arranged in the main scanning direction are arranged in the main scanning direction and the sub scanning direction, and the optical magnification of each light emitting block is negative. Storage means for storing image data to be supplied to each of the light emitting elements, the light emitting blocks arranged in a plurality of rows in the sub scanning direction being divided and grouped for each sub scanning direction. Provided,
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 to be supplied to each of the grouped light emitting elements, and a step of reading out image data of one group to form an imaging spot on the image carrier. Forming image formation spots on the image carrier sequentially from another group of image data after a predetermined timing, and forming the image formation spots aligned in the main scanning direction of the image carrier. An image forming method.

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