JP2000242053A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make reducible the memory capacity for image data storage in an image forming device. SOLUTION: This image forming device has plural memory blocks where each color image data necessary for one transfer operation is written at every transfer operation respectively and the blocks corresponding to each color are provided so as to be increased in the number one by one from one block proportional to the color number. And the image data storage memory is made to be such as each color image data stored in the memory blocks is increased one by one in the number of colors and blocks from the 1st single block and is finally read block by block sequentially on all colors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orthogonal transfer type image forming apparatus for transferring a toner image to a recording medium by rubbing a toner image carrier in a direction perpendicular to a conveying direction of a recording medium such as printing paper. is there.

[0002]

2. Description of the Related Art In recent years, toner-type image forming apparatuses capable of forming clear images with excellent resolution, such as laser printers, have become widespread.

[0003] Among such toner-type image forming apparatuses, as disclosed in Japanese Patent Application No. 7-328600, the toner image carrier is rubbed in a direction perpendicular to the conveying direction of the printing paper (recording medium). An image forming apparatus of the orthogonal transfer type, in which a toner image is transferred to a printing sheet in small steps at a time by (rubbing), is very suitable for promoting miniaturization of a product due to its configuration.

[0004]

The data format read by an image reading device such as a scanner is a data format in which pixels having RGB data per pixel are continuous, and this data is subjected to image processing for printing. In order to print the YMCK data resulting from the above, the YMCK data is temporarily written into an image data storage
It is necessary to control a read address in the order of data to be transmitted to the laser scanning unit, and to transmit data to the laser scanning unit.

Here, in the image forming apparatus of the orthogonal transfer system, data used in one printing (forming a latent image on a toner image carrier and transferring a toner image to printing paper) is color (Y).
MCK) has a different data area of the original image. Conventionally, since data is collectively handled in each color unit of YMCK, the first color data (for example, Y data) to be printed until the last color data to be printed (for example, K data) is written to an image. Since the data must be stored in the data storage memory, there is a problem that the memory capacity increases.

That is, in the above-described conventional technique, FIG.
As shown in (1), 16 memory blocks for each color are required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of reducing a memory capacity for storing image data when printing data read by the image reading apparatus.

[0008]

In order to solve this problem, an image forming apparatus according to the present invention is a closed-loop belt-shaped toner on which an electrostatic latent image is formed by being rotated by a plurality of toner image bearing rollers. An image carrier, a developing unit that contains a plurality of color toners and supplies toner to the electrostatic latent image to form a toner image; and a toner image formed on the toner image carrier that is orthogonal to the transport direction of the recording medium. Transfer opposing roller that presses and transfers to the recording medium while moving in the direction of movement, and each color image data necessary for one transfer operation is written for each transfer operation, and one block corresponding to each color is provided. And a plurality of memory blocks provided in such a number as to increase by one in proportion to the number of color numbers, and the image data of each color stored in this memory block is a single block of the first color. It is obtained by a configuration having an image data storage memory to be read one by one block per Luo color depth and while increasing the number of blocks, one eventually all colors.

[0009] This makes it possible to reduce the memory capacity for storing image data when printing data read by the image reading device.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, there is provided a closed loop belt-shaped toner image carrier on which an electrostatic latent image is formed by being rotated by a plurality of toner image carrier rollers. Developing means for containing toner of a color and supplying toner to the electrostatic latent image to form a toner image; and moving the toner image formed on the toner image carrier in a direction orthogonal to the conveying direction of the recording medium. A transfer opposing roller that presses and transfers to a recording medium, each color image data required for one transfer operation is written for each transfer operation, and a block corresponding to each color is proportional to the number of colors from one block A plurality of memory blocks provided in such a number as to increase by one each, and the image data of each color stored in this memory block is obtained by calculating the number of colors and the number of blocks from the single block of the first color. An image data storage memory which is sequentially read one block at a time for all colors while increasing by one, and a memory for storing image data when printing data read by the image reading device. This has the effect that the capacity can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a schematic diagram showing the configuration of an image forming apparatus of the orthogonal transfer type according to an embodiment of the present invention, FIG. 2 is a perspective view schematically showing a transfer mechanism of the image forming apparatus of FIG. 1, and FIG.
4 is an explanatory diagram showing a transfer operation by the image forming apparatus of FIG. 1, FIG. 4 is a block diagram showing a processing mechanism of image data in the image forming apparatus of FIG. 1, and FIG. FIGS. 6 and 7 are explanatory diagrams showing control of writing and reading of image data in the image forming apparatus of FIG. 1, and FIG. 7 is an explanatory diagram showing read image data by the control of FIG.

As shown in FIG. 1, in the orthogonal transfer type image forming apparatus according to the present embodiment, a toner image carrier 1 which is a closed loop belt-shaped photosensitive member having an organic photoconductive material coated on its surface is used. Supported by the transfer opposing roller 8 and the toner image carrier rollers 9a, 9b, 9c,
It rotates around in the direction of arrow A.

Around the periphery of the toner image carrier 1, a charging means 2 for uniformly charging the surface of the toner image carrier 1 in the direction of its rotation, and a laser beam is applied on the charged toner image carrier 1. Exposure means 6 for irradiating the latent image 6a to form an electrostatic latent image corresponding to image data, and applying toner to the latent image portion of the toner image carrier 1 formed by the exposure means 6 to visualize the electrostatic latent image. Developing means 3, a cleaning means 4 for removing residual toner remaining on the toner image carrier 1 after transfer, and a charge eliminating means 5 for removing residual potential on the toner image carrier 1 are arranged in this order.

The developing means 3 contains toner 3a, and is provided with a developing roller 3b for attaching the toner 3a to the electrostatic latent image formed on the toner image carrier 1.

The developing means 3 is provided with a yellow (hereinafter, referred to as yellow)
Called "Y". ), Magenta (hereinafter, referred to as “M”), cyan (hereinafter, referred to as “C”), and black (hereinafter, referred to as “K”) four color toners are arranged in one box. That is, four color toners are developed on the toner image carrier 1 at a time by the developing unit width of each color.

The printing paper (recording medium) 7 is a transfer plate 1
0, and as shown in FIG.
The toner image carrier 1 is transported in a direction (print paper transport direction) X orthogonal to the direction in which the toner image carrier 1 rotates (the direction of arrow A).

Next, a mechanism for processing image data in such an image forming apparatus will be described.

Here, the image data storage memory 12 (FIG. 4) stores image data for giving information on the electrostatic latent image formed by the exposure means 6.

As shown in FIG. 4, the control mechanism for the image data includes an image data storage memory 12 for storing the image data.
A write address generation circuit 13 for generating a memory address when writing image data thereon, a read address generation circuit 14 for generating a memory address when reading image data from the image data storage memory 12, and an image data storage memory 12. On the other hand, it comprises an address selector 15 for switching the addresses generated by the write address generation circuit 13 and the read address generation circuit 14.

As shown in FIG. 5A, each color data of YMCK, which is image data for writing, is represented by Y1, Y2.
.., M1, M2, C1, C2, K1, K
There are 2 ...

On the other hand, as shown in FIG. 5B, the image data storage memory 12 includes a memory block y1 for storing one color for storing Y color from the write image data for one transfer operation. Two memory blocks m1 and m2 for storing M colors, three memory blocks c1, c2 and c3 for storing C colors, and four memory blocks k1, k2 and k3 for storing K colors. , K4
Of 10 memory blocks in total.

FIG. 5 shows the ten blocks.
The image data for writing shown in (a) is written, and the image data is read while performing address control so that the read data has an intended data array.

Next, the operation of the image forming apparatus having the above configuration will be described.

When the start of an image forming operation is instructed by a control unit (not shown) of the image forming apparatus, the image data is written into an image data storage memory, and is driven by a toner image carrier roller driving unit (not shown). The transfer opposing roller 8 and the toner image carrier rollers 9a, 9b, 9c rotate, and the toner image carrier 1 starts to rotate in the direction of arrow A.

After the surface of the toner image carrier 1 is charged by the charging means 2 in accordance with the contents of the image to be formed, a plurality of colors are read from the exposure means 6 in accordance with data read out from the image data storage memory 12 in a plurality of colors. Irradiated laser light 6a
Thereby, an electrostatic latent image is formed on the charged portion.

When the portion of the toner image carrier 1 where the electrostatic latent image is formed reaches the position of the developing means 3, the developing roller 3b disposed on the developing means 3 is driven by a developing roller driving means (not shown). It rotates and comes into contact with the toner image carrier 1. As a result, the electrostatic latent image is developed by the toner 3a attached to the surface of the developing roller 3b while the toner image carrier 1 is nipped and moved between the developing roller 3b and the toner image carrier roller 9b. A toner image 3c is formed on the image carrier 1.

In this way, a toner image 3c corresponding to one transfer is formed on the toner image carrier 1,
The transfer of the toner image 3c onto the printing paper 7 is performed.

That is, first, the transfer of the toner image 3c is performed.
When the leading end p1 of the toner image 3c formed on the toner image carrier 1 is substantially at the same position as the end p2 of the image forming area of the printing paper 7, the toner image carrier rollers 9a, 9
b, 9c and the toner image carrier 1
Stop the rotation of.

Next, the paper transport roller 11 is rotated by paper transport means (not shown), and the printing paper 7 is moved in the direction (X direction) orthogonal to the rotation direction of the toner image carrier 1 as shown in FIG. Is transferred to a predetermined position on the transfer plate 10.

When the transfer of the printing paper 7 is completed, the transfer opposing roller 8 is driven by the transfer opposing roller driving means (not shown).
Is moved along the printing paper 7 in the direction of arrow B shown in FIG. 3 (Y direction in FIG. 2) from the transfer start position p3 to the transfer end position p4.

During the parallel movement of the transfer opposing roller 8,
The transfer opposing roller 8 and the toner image carrier 1 are pressed against the printing paper 7. At this time, a toner image 3c on the toner image carrier 1 is attracted to the transfer plate 10 by applying a reverse polarity bias to the toner image 3c to the transfer plate 10 as a whole. Transcribed above.

When the transfer of the toner image 3c is completed in this way, the print paper transport roller 11 rotates again, and the print paper 7 on which the image is formed is transported. When the discharge of the printing paper 7 is completed, the toner image carrier 1 starts to rotate again, and the cleaning means 4 removes the toner 3a remaining on the portion of the toner image carrier 1 where the toner image 3c has been transferred. Then, the charge on the toner image carrier 1 is eliminated by the charge removing means 5.

As described above, predetermined images such as characters and figures are formed on one print sheet 7, and similar image forming operations are sequentially repeated as necessary.

Next, the operation of writing and reading image data to and from the image data storage memory 12 will be described.

Here, as shown in FIG. 5B, ten memory blocks y1, m1, m2, c1, c2, c3, k1, k2, k constituting the image data storage memory 12 are provided.
3 correspond to the write data Y1, M1, M2, C1, C2, C3, K1, K2,
It is assumed that K3 and K4 exist.

First, the write data Y1 is stored in the memory block y1, and the write data M1 is stored in the memory block m1.
Next, a write address is generated from the write address generation circuit 13 so that the write data C1 is written into the memory block c1 and the write data K1 is written into the memory block k1, and the data is written (FIG. 6A).
reference). At this time, the direction D in which data is written is as shown in FIG.
As shown by the arrow in (a), this is a direction orthogonal to the transport direction of the printing paper 7.

As shown in the first write data column of FIG. 6A, when the writing of the data Y1, M1, C1, and K1 is completed, the data is indicated by a thick frame in the first transfer data column of FIG. 6B. Thus, the read address generation circuit 14 generates a read address so as to read the data Y1 stored in the memory block y1. The data reading direction at this time is parallel to the transport direction of the printing paper 7. Since a latent image is formed on the toner image carrier 1 in accordance with the read data Y1, when a transfer operation is performed, a toner image corresponding to the data Y1 is obtained on the printing paper 7.

Next, the write data Y2 is overwritten on the memory block y1, the write data M2 is written on the memory block m2, and the write data C2 is written on the memory block c2.
Next, a write address is generated from the write address generation circuit 13 so as to write the write data K2 to the memory block k2, and the data is written.

As shown in the second write data column of FIG. 6A, when the writing of the data Y2, M2, C2, and K2 is completed, the data is indicated by a thick frame in the second transfer data column of FIG. 6B. As described above, the read address generation circuit 14 generates a read address and performs read control so that the data Y2 stored in the memory block y1 and the data M1 stored in the memory block m1 are read. Since a latent image is formed on the toner image carrier 1 in accordance with the read data Y2 and M1, when a transfer operation is performed, a toner image corresponding to the data Y2 and M1 is obtained on the printing paper 7.

Next, the write data Y3 is overwritten on the memory block y1, the write data M3 is written on the memory block m1, and the write data C3 is written on the memory block c3.
Next, a write address is generated from the write address generation circuit 13 so as to write the write data K3 to the memory block k3, and the data is written.

As shown in the third write data column of FIG. 6A, when the writing of the data Y3, M3, C3, and K3 is completed, the data is indicated by a thick frame in the third transfer data column of FIG. 6B. Thus, the read address generation circuit 14 generates a read address so that the data Y3 stored in the memory block y1, the data M2 stored in the memory block m2, and the data C1 stored in the memory block c1 are read. Performs read control. Since a latent image is formed on the toner image carrier 1 in accordance with the read data Y3, M2, and C1, when the transfer operation is performed, the toner image corresponding to the data Y3, M2, and C1 is printed on the printing paper 7. Is obtained.

Next, the write data Y4 is overwritten on the memory block y1, the write data M4 is written on the memory block m2, and the write data C4 is written on the memory block c1.
Next, a write address is generated from the write address generation circuit 13 so as to write the write data K4 to the memory block k4, and the data is written.

As shown in the fourth write data column of FIG. 6A, when the writing of the data Y4, M4, C4, and K4 is completed, the data is indicated by a bold frame in the fourth transfer data column of FIG. 6B. Thus, the data Y4 stored in the memory block y1, the data M3 stored in the memory block m1, the data C2 stored in the memory block c2,
The read address generation circuit 14 generates an address and performs read control so that the data K1 stored in the memory block k1 is sequentially read. Then, since a latent image is formed on the toner image carrier 1 in accordance with the read data Y4, M3, C2, and K1, when a transfer operation is performed,
A toner image corresponding to the data Y4, M3, C2, K1 is obtained on the printing paper 7.

Thus, for the first time at this stage, the data Y
A color image in which four colors of data corresponding to 1, M1, C1, and K1 are superimposed is generated on the printing paper. The image width of this portion is equal to the development width of one color.

By sequentially repeating the above operations, the write data is written to and read from the image data storage memory 12, and a series of processes of forming a latent image, transferring and forming a toner image is performed, whereby printing is performed. A color image is formed on the entire sheet 7 by superimposing the four color toner images.

FIG. 7 shows read image data corresponding to the number of times of transfer. Note that, in FIG. 7, the arrow indicates the reading direction.

As described above, in this embodiment, the image data of each of the colors Y, M, C, and K necessary for one transfer operation is one.
Each time the transfer operation is performed, a block corresponding to each color is written from one block to a color number (that is,
For example, Y is the first color, M is the second color, C is the third color, and K is four.
The number of colors increases by one in proportion to the number of colors (ie, the number of these colors in the case of color # 1) (that is, Y of the first color is one, M of the second color is two, C of the third color is three, A plurality of memory blocks are provided in such a number as to increase the number of K of the fourth color to four, and the image data of each color stored in the memory block is stored in the first color (here, the first color). From the single block of the first color (Y) (here, one block provided for the first color Y), the number of colors and the number of blocks are increased by one, and finally, for all the colors. Data is read out one block at a time.

As described above, when writing the image data for printing to the image data storage memory 12 which is the image memory for printing, memory address control is performed such that only necessary minimum data is written for each color. Thus, printing can be performed with a small number of image data storage memories 12.

Accordingly, it is possible to reduce the capacity of the image data storage memory 12 when printing the image data read by the image reading device.

[0051]

As described above, according to the present invention, it is possible to reduce the capacity of the image data storage memory when printing image data read by the image reading apparatus. Can be

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an orthogonal transfer type image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a transfer mechanism of the image forming apparatus of FIG. 1;

FIG. 3 is an explanatory diagram illustrating a transfer operation by the image forming apparatus of FIG. 1;

FIG. 4 is a block diagram showing a processing mechanism of image data in the image forming apparatus of FIG. 1;

FIG. 5 is an explanatory diagram showing the structure of the image data storage memory of FIG. 4;

FIG. 6 is an explanatory diagram showing control of writing and reading of image data in the image forming apparatus of FIG. 1;

FIG. 7 is an explanatory diagram showing read image data under the control of FIG. 6;

FIG. 8 is an explanatory diagram showing a structure of an image data storage memory in a conventional image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Toner image carrier 3 Developing means 3a Toner 3c Toner image 7 Printing paper (recording medium) 8 Transfer opposing roller 9a-9c Toner image carrier roller 12 Image data storage memory

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiro Ezaki 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor ▲ YABU ▼ Hidefumi 1006 Okadoma Kadoma, Kazuma Osaka Pref. (72) Inventor Hirofumi Kasedo 1006 Kazuma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.F-term (reference) 2H030 AA05 AD12 BB02 BB23 BB43 5C074 AA11 BB03 DD16 DD24 GG01 HH02

Claims (1)

[Claims] 1. A closed loop belt-shaped toner image carrier on which an electrostatic latent image is formed by being rotated around by a plurality of toner image carrier rollers, and toners of a plurality of colors are accommodated. Developing means for supplying a toner to form a toner image; and transferring the toner image formed on the toner image carrier to the recording medium by pressing while moving the toner image in a direction orthogonal to the recording medium conveyance direction. An opposing roller, in which each color image data required for one transfer operation is written for each transfer operation, and the blocks corresponding to each color are increased one by one in proportion to the number of colors from one block. A plurality of memory blocks are provided, and the image data of each color stored in the memory blocks does not increase the number of colors and the number of blocks by one from the single block of the first color. An image forming apparatus, comprising an image data storage memory to be read one by one block per Luo finally all colors.