JPH0556254A - Control circuit for image forming device - Google Patents

Abstract

PURPOSE:To improve the picture quality by improving the outline of an image. CONSTITUTION:Page description data stored in a page description data buffer 21 are converted into bit map image data by a page description interpreter 22 and stored in a bit map memory 23. After the bit map image data of an N line are fetched into a first line buffer memory 25, they are segmented by the rectangular area of an NXN bits, stored in a register 26, and subsequently, the data of the NXN bits become an address signal and inputted to a dot shape LUT 27. Dot diameter data 27a and dot position data 27b to show the size and recording position of the recording dot corresponding to the data of the NXN bits are outputted from the dot shape LUT 27. Based on the dot diameter data 27a and the dot position data 27b, the dot is recorded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic printer or a copying machine for performing high-quality recording (image formation) using vectorized data, and more particularly, to recording quality. The present invention relates to a control circuit of an image forming apparatus to be improved.

[0002]

2. Description of the Related Art Laser printers, light-emitting diode printers (L printers) are superior to other printers such as thermal transfer printers and ink jet printers in terms of printing speed and resolution.
ED printers), liquid crystal printers, and other electrophotographic printing optical printers are becoming less expensive, and can be used not only as general-purpose large-sized computers, office computers, minicomputers, workstations, etc., but also as printers for personal computers. It is becoming popular.

The pixel density (resolution) of a laser printer, which is a kind of such an electrophotographic image forming apparatus, is currently 300 dpi (dot per inch). Therefore, the recording signal (recording data) output from the host device (host computer, etc.) to the laser printer is also
Many are compatible with 300 dpi.

However, in an optical printer having a pixel density of 300 dpi, when a curve such as the outer circumference of a circle 10 (see FIG. 7A) is recorded as shown in FIG. 5, it is enlarged to FIG. As shown in the figure, there is a drawback that the jaggies (jagged edges) on the outer periphery become conspicuous (in the same figure (b),
A plurality of black circle dots (pixels) are dots forming a circle 10).

By the way, as a method for improving such a defect, for example, there is a method of increasing the pixel density to a predetermined value or more. However, such a method of simply increasing the pixel density has the following drawbacks.

Since it is necessary to improve the accuracy of the printer engine section, the cost becomes high. Currently, 300 dpi bitmap fonts that are installed in mainstream optical printers cannot be used.

At present, the widely distributed 300 dpi input device (image scanner or the like) cannot be used.
The causes of the above reasons are
In order to improve the accuracy of the printer engine section, it is necessary to increase the pixel density in the sub-scanning direction, that is, to increase the pitch of the paper feed and the photoconductor drum feed, but if this is realized, it will be extremely expensive. This is because However, increasing the pixel density in the main scanning direction can be realized relatively easily and at low cost because it is only necessary to increase the frequency for modulating the exposure laser light provided in the optical head. A method of increasing the pixel density using this method is disclosed in USP 4,847,641.

In US Pat. No. 4,847,641 described above, as shown in FIG. 6, the positioning accuracy of pixels in the main scanning direction is tripled, and the size of pixels (dots) is changed in 12 steps to improve the image quality. It is intended to improve. The method will be described in more detail. Pixels of an input image are cut out with a mask of a predetermined size whose center position is a pixel (dot) to be recorded, and a ROM (read only
If a matching template is found by comparing and collating with a plurality of patterns (templates) written in the memory), based on the information stored in advance in association with the template, It corrects the position and size. In the method shown in FIG. 6, the serialized input data (SERIALIZED DATA) 90 is cut out by a sample window (SAMPLING WINDOW) 109 composed of 47 dots centered on the recording pixel 111, and the right side of FIG. 115 (TEMPLATE) shown in
The position and the size of the recording pixel (recording dot) 111 are corrected when a plurality of templates (TEMPLATE) having the same configuration as the sample window to be cut out are compared with each other. In this example, the sample window 10
9 and the template 115 are detected to be coincident with each other, the recording dots 111 are made smaller so as to shift the position to the right, although not particularly shown. As a result, dot collapse at the intersection is reduced.

[0009]

However, in the method of USP 4,847,641 as described above, in order to deal with all the states (patterns) of the sample window composed of 47 dots, the template of 47-bit structure is used. It is not possible at present because it is necessary to prepare a memory with an enormous storage capacity for storing 2 ⁴⁷ pieces. Further, the sample window is cut out from the bitmap data of the resolution (pixel density) of the original image forming apparatus (recording apparatus) to change the position and size of the recording dot.
Therefore, there is a drawback that accurate contour extraction cannot be obtained. Further, since the bitmap data having the same resolution as that of the original image forming apparatus is used, the area ratio of the recording dots per unit area becomes the same as the original image when the position and size of the recording dots are changed. As described above, it is difficult to determine the size of the recording dot, and no consideration has been given to that. For this reason, there is also a drawback that the area ratio of the recording dots per unit area changes, and the gradation of the image to be originally recorded is different (good gradation reproduction cannot be obtained).

It is an object of the present invention to realize a control circuit of an image forming apparatus capable of good contour expression and good gradation reproduction and capable of high quality image recording.

[0011]

FIG. 1 illustrates the principle of the present invention. The present invention is premised on a control circuit of an image forming apparatus which expands image data represented by vectorization into bitmap image data and performs recording.

The bitmap image data creating means 1 converts the input image data represented by vectorization into bitmap image data having a resolution higher than that of the recording mechanism section (engine section) of the image forming apparatus. expand.

The recording dot setting means 2 sequentially cuts out the bitmap image data expanded by the bitmap image data creating means 1 in a predetermined block unit, and based on the contents in each cut-out block, the recording is performed. The print dots corresponding to the resolution of the mechanical unit are generated, and area data that specifies the area of each print dot that is generated and position data that specifies the print position are set.

The recording control means 3 is a recording dot setting means 2
Based on the area data and recording position of each recording dot set by, the recording dot is controlled to be recorded at the position specified by the position data in the area specified by the area data.

The recording dot setting means 2 sets the total area of all the recording dots to be set to be equal to the total area of the recording dots created by the bitmap data creating means 1, for example. Then, the area data of each recording bit is determined.

The recording dot setting means 2 is, for example,
As described in claim 3, the position data of each recording dot is determined according to the arrangement state of the recording dots in the cut block.

[0017]

According to the present invention, the vectorized image data input by the bitmap image data creating means 1 is converted into bitmap image data having a resolution higher than that of the recording mechanism of the image forming apparatus. It will be rolled out sequentially. Then, these bitmap image data are stored in the bitmap memory for each page, for example.

Subsequently, the bitmap image data is
The recording dot setting unit 2 cuts out each predetermined block unit, and the recording dot setting unit 2 creates a storage dot corresponding to the resolution of the recording mechanism unit based on the data content in each cut out block. For example, one page is generated. At this time, area data designating the area of each recording dot to be generated and position data designating a recording position are set. In the setting of each of the above-mentioned data, for example, the total area of the recording dots to be generated is set to be equal to the total area of the recording dots bit-developed into the high resolution (the area ratio of the recording dots per unit area changes. The area data of each recording dot is determined, and the position data of each recording dot is determined based on the arrangement state of the recording dots in the cut block. Further, subsequently, the recording control means 3 determines, based on the area data and the position data of each recording dot generated by the recording dot setting means 2, that each recording dot has an area designated by the area data, and The recording mechanism unit (engine unit) is controlled so that the recording is performed at the position designated by the position data.

Therefore, after expanding the vectorized image data into bitmap image data having a resolution higher than that of the recording mechanism of the image forming apparatus,
The bitmap image data is divided into blocks of a predetermined size, and based on the data content in each block,
For each block, one dot is sequentially recorded while changing the size and the recording position so that the area ratio of the recording dots in the block does not change. It is possible to record dots with good contour expression at the same resolution and the same gradation as the resolution that the user has.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a configuration diagram of a main part relating to the present invention of a laser printer according to an embodiment of the present invention.

In the figure, the page description data is image data for recording which is transmitted from a higher-level device (host computer etc.) and which is expressed in a vectorized representation described in a predetermined page description language. Is.

This page description data is stored in a page description data buffer 21 which is a buffer memory for temporarily storing the page description data via an interface (not shown).

The page description interpreter 22 is an interpreter that sequentially reads page description data from the page description data buffer 21 and develops the page description data into bitmap image data.

The bitmap memory 23 is a page memory for storing one page of bitmap image data developed by the page description interpreter 22. When the print command is read from the description data buffer 21, the page description interpreter 22 serially reads the bitmap image data for N lines centered on the recording dot from the bitmap memory 23, and outputs the bits for the N lines. The map image data is stored in the first line buffer memory 25. The reading of the bitmap image data is sequentially performed in the main scanning direction and the sub scanning direction from the bitmap image data of the top line of the page.

The first line buffer memory 25 has N serial input shift registers 25-1, 25-2, ... Which temporarily hold bit map data for one line.
.. 25-N, and the above N shift registers 25
-1, 25-2, ... 25-N are cascade-connected. These N shift registers 25-1 and 25-2
Although not shown in the drawing, 5-2, ..., 25-N sequentially shift the bit map image data read from the bit map memory 23 by 1 bit each time a clock pulse is applied from the page description interpreter 23. Go

The register 26 is controlled by the page description interpreter 24 and is used for the first line buffer memory 2 described above.
5 shift registers 25-1, 25-2, ... 25
-N is a parallel input register that simultaneously stores data of a predetermined bit output from -N.
Holds the bitmap image data of a block of N × N pixels centered on the recording dot in the form of serial data.

The dot shape LUT 27 is the register 2 described above.
6 shows data (dot diameter data 27a) indicating the diameter of a dot (recording dot) to be actually recorded and recording position corresponding to bitmap image data of various patterns made up of N × N bits stored in FIG. A memory that stores data (dot position data 27b), such as a ROM,
It consists of RAM (random access memory) and the like. In this embodiment, N × stored in the register 26
By inputting N-bit bitmap image data into the dot shape LUT 27 as an address signal,
The dot diameter data 27a and the dot position data 27b corresponding to the bitmap image data are output from the dot shape LUT 27 to the second line buffer memory 28.

The second line buffer memory 28 is a memory for storing dot diameter data 27a and dot position data 27b of one line of recording (image forming) dots output from the dot shape LUT 27.

The laser driving driver 29 sequentially reads out the dot diameter data 27a and the dot position data 27b of the recording dots for one line stored in the second line buffer memory 28 in the recording order, and each recording dot. Based on the data 27a and 27b of the photoconductor drum 3, the drive control for controlling the light emission time of a laser (not shown) installed in the optical head 31 of the exposure optical system 30 is performed.
By controlling the amount of exposure that is irradiated onto 2, the electrostatic latent image of the dot having the diameter indicated by the dot diameter data 27a is formed on the photosensitive drum 32 at the position indicated by the dot position data 27b. The control of the dot formation position is performed by the well-known rotation control of a rotating polygon mirror (polygon mirror).

Next, the operation of the laser printer having the above structure will be described. When the page description data transmitted from the host device is stored in the page description data buffer 21,
The page description interpreter 22 reads the page description data from the page description data buffer 21, interprets the page description data, and writes the vectorized page description data in a predetermined area on the bitmap memory 23. Expand to the corresponding bitmap image data. At this time, the page description interpreter 22 develops the bitmap image data having a resolution N times the recordable resolution (pixel density) that the laser printer originally has. That is, the number of bits (dots) is expanded to N times in both the main scanning direction and the sub scanning direction.

The above operation is repeated every time the page description data is transmitted from the higher-level device, and the bitmap image data having the N times the resolution is sequentially expanded in the bitmap memory 23. Then, when a print command is transmitted from the host device, the page description interpreter 22 sequentially reads out the bitmap image data stored in the bitmap memory 23 in the main scanning direction and the sub scanning direction, and the first The data is sent to the line buffer memory 25 bit by bit. Then, the N serial input shift registers 25-1 of the first line buffer memory 25,
25-2, ..., 25-N, as described above, are synchronized with the clock pulse applied from the page description interpreter 22, and the bitmap image data for one line expanded to N times the resolution is dot by dot. Enter serially in order. Then, the N serial input shift registers 2
When the bitmap image data for one line is fetched into all of 5-1, 25-2, ... 25-N, the N serial input shift registers 25- are controlled by the page description interpreter 22. 1,25-2, ...
The N-bit bitmap image data is read in parallel from 25-N, and a block of the N × N pixel bitmap image data is stored in the register 26. That is, the pixels forming the N × N rectangular area composed of the N pixels of each line of the N lines are stored in the register 26.

Then, the N stored in the register 26
A block of bitmap image data of × N pixels is input as an address signal to the dot shape LUT 27, and the dot diameter data 27a and the dot position data 27b stored at the address of the dot shape LUT 27 indicated by the address signal are the second. Output to the buffer memory 28.

The above operation is sequentially performed for each line of the bitmap image data of one line (one scan in the main scanning direction recorded in the exposure optical system 30) stored in the bitmap memory 23. Line buffer memory 28
In the area, the dot diameter data 27a and the dot position data 27b of the recording dots for one scan in the main scanning direction of the exposure optical system 30 are accumulated.

When the dot diameter data 27a and the dot position data 27b of the recording dots for one scan in the main scanning direction are accumulated in this way, the laser drive driver 29 causes the exposure optical of the printer engine section to be exposed. In synchronization with the start of scanning of the system 30, the second line buffer memory 28
From the above, the dot diameter data 27a and the dot position data 27b of the recording dot for one scan in the main scanning direction are sequentially read out in the scanning order, and the dot diameter data 27a and the dot position data 27b are read at the position indicated by the dot position data 27b on the photosensitive drum 32. 27a
In order to form an electrostatic latent image of dots having a diameter shown by, rotation (or hologram scanner) of a rotating polygon mirror (polygon mirror) (not shown) of the exposure / optical system 30 and laser light are modulated. The frequency is controlled.

Next, a specific operation of the laser printer of this embodiment will be described with reference to FIGS. 3 and 4. When the page description data for drawing the circle 40 with the inside filled in as shown in FIG.
The page description interpreter 22 has a resolution of 300d included in the laser printer of this embodiment, as shown in FIG.
It is expanded to bitmap image data having a resolution of 900 dpi, which is three times the pi (N = 3). Therefore, the rectangular area composed of 3 × 3 cells 50 shown in FIG.
Laser printer with a resolution of 0 dpi records 1
It corresponds to the size of the grid of dots. The black dots (recording dots) 51 and the white dots (non-recording dots) 52 shown in FIG. 7B are recorded as “1” and “0” on the bitmap memory 23, respectively.

Then, the image data of the bit map image as shown in FIG. 7B stored in the bit map memory 23 is fetched into the first line buffer memory 25 in units of three lines and then in the sub scanning direction. Are sequentially cut out in the main scanning direction for each rectangular region of 3 × 3 bits (N = 3) and stored in the register 26 in the form of serial data.

Here, in FIGS. 4A to 4E, the circle 4
5 shows 5 types of patterns of a 3 × 3 bit (N = 3) cut-out rectangular area corresponding to the outer peripheral portion of 0, and the position and size of the recording dot corresponding to each pattern.

3 × 3 of the pattern shown on the left side of FIG.
In the bit rectangular area 51, since all the bits indicate the recording dots (= "1"), the dot shape LUT 27
The address signal input to is “512” (= 11111
1111 ”), the dot diameter data 27a and the dot position data 27b stored at the address“ 512 ”of the dot shape LUT 27 are read out, and the laser drive driver 29 and the exposure optical system 30 are used to read the same (a). As shown on the right side of (), a recording dot 71 having a maximum area which can be accommodated in the grid 62 corresponding to the resolution of 300 dpi is recorded in the center of the grid 62. That is, in this case, 3
Since it corresponds to a 1-bit recording dot when expanded to bitmap image data at a resolution of 00 dpi, the standard dot recording is performed on the grid 62 as in the case of recording at a resolution of 300 dpi.

Next, in the 3 × 3 bit rectangular area 52 having a pattern as shown on the left side of FIG. 7B, all the bits are non-recorded dots, so the dot shape LUT 27 is used.
The dot diameter data 27a and the dot position data 27b stored at the address “0” (= “000000000000”) of the are read. Then, as shown on the right side of FIG. 7B, no dots are recorded. That is, in this case, since it corresponds to the non-recorded dots when the bitmap image data is developed at the resolution of 300 dpi, in this case, the dots are recorded on the grid 62 as in the case of the recording at the resolution of 300 dpi. Is not done.

Further, in the case of the rectangular region 53 of 3 × 3 bits shown on the left side of FIG. 7C, three recording dots are gathered on the upper left side. This is a pattern corresponding to the lower right portion of the outer circumference of the circle 40. In this case, the address signal input to the dot shape LUT 27 is "41
6 ”(=“ 110100000 ”), and dot type L
Dot diameter data 27 from address "416" of UT27
a and the dot position data 27b are read out, and as shown on the right side of FIG. 7C, the recording dot 72 having the area of 1/3 of the maximum recording dot 71 is recorded on the left side of the grid 62. To be done. The area of this recording dot 72 is
In a rectangular area of 3 × 3 bits, the total number of bits (9
It is determined by the fact that 3 bits corresponding to 1/3 of (bit) are recording dots.

Subsequently, in the case of a rectangular area 54 of 3 × 3 bits as shown in FIG. 7D, 6 recording dots are gathered on the right side. This is the corresponding pattern in the left central part of the outer circumference of the circle 40. Then, in this case, the address signal input to the dot shape LUT 27 is "21".
9 ”(=“ 011011011 ”), and based on the dot diameter data 27a and the dot position data 27b read from the address“ 219 ”of the dot shape LUT 27, dots as shown on the right side of FIG. 73 is recorded. The area of the dot 73 is the total number of dots (9 dots) in the rectangular area 54 shown in FIG.
Since the ratio of the recording dots to 2 is 3/3 (= 6/9), the recording dot 73 having the area of 2/3 of the maximum recording dot 71 shown on the right side of FIG. Record to the right of 62. That is, also in this case, the area of the recording dot 73 is determined by the ratio of the recording dot in the 3 × 3 bit rectangular area 54 obtained by developing the bitmap image data having the triple resolution.

Then, as shown in FIG.
In the case of the × 3 bit rectangular area 55, two recording dots are gathered in a point-symmetrical manner at the upper left and the lower right. This is, for example, a boundary area between the upper left portion of the circle 40 (the two lower right recording dots of the rectangular area 55 correspond) and another figure (the upper left two recording dots of the rectangular area 55 correspond). Is a pattern corresponding to. Then, in this case, the address signal input to the dot shape LUT 27 is "29".
7 ”(=“ 100101001 ”), and based on the dot diameter data 27a and the dot position data 27b read from the address“ 297 ”of the dot shape LUT 27, the recording dot 74 as shown on the right side of FIG. Is recorded in the center of the grid 62. In addition, this recording dot 7
In the area of 4, the ratio of the recording dots in the cut out rectangular area 55 shown on the left side of FIG.
Since it is / 9, it is determined to be 4/9 of the recording dot 71 of the maximum recordable area shown on the right side of FIG.

Thus, in this embodiment, the circle 40
Bit map image data of 900 dpi which is three times the 300 dpi resolution originally possessed by the laser printer of the present embodiment.
It is expanded into the bitmap image data of i, and the bitmap image data is divided into 3 × 3 bit rectangular areas,
The recording / non-recording of recording dots, the size of recording dots, and the recording position are determined for each rectangular area. In addition, in the present embodiment, since the bitmap data expanded to the resolution of 900 dpi is used, the extracted 3 ×
It is easy to calculate the area ratio of the recording dots in the 3-dot rectangular area, and the size of 1 dot recorded in the rectangular area becomes the same as the area ratio of the recording dots in the cut-out rectangular area. Has been decided. For this reason, it is possible to obtain gradation reproduction similar to that when recording is performed at a conventional resolution of 300 dpi. Incidentally, FIG.
The cutout patterns of the 3 × 3 bit rectangular area shown in (a) to (e) are examples, and other rectangular areas of various patterns are cut out, and the size of the area of the recording dot and The recording position in the grid 62 will be determined.

By the method as described above, the shape of the outer peripheral portion of the circle 40 recorded by the laser printer having the resolution of 300 dpi of the present embodiment based on the bitmap image data having the resolution of 900 dpi shown in FIG. 3A. Is shown in FIG. As is apparent from a comparison between FIG. 3C and the shape of the outer peripheral portion of the circle 10 recorded by the conventional laser printer having the same resolution (300 dpi) shown in FIG. The contours of the outer circumference of the circle are smoother in the recording by the laser printer, the jaggies in the outer periphery of the circle, which were conspicuous in the recording by the conventional laser printer, are eliminated, and the contour is favorably improved. That is, in the recording by the laser printer of the present embodiment, the conventionally recorded dot 14 (see FIG. 5B) has a dot 61 (FIG. 3C) having an area smaller than that of the dot 14.
(See above), the standard dots (the above-mentioned dots 12, 14 to 1) are respectively provided below the dots 15, 16, 17, 18 (see FIG. 5B) on which printing is performed in the same manner as the conventional printing.
8 etc.), dots 62, 63, 6 with a smaller area than
4 (see FIG. 3C) is newly recorded. Then, the newly recorded dots 61, 62, 6
The total area of 3,64 is made to be the same as the area of the dot 14. As described above, in the present embodiment, the size of the recording dots to be deformed is determined so that the area ratio of the recording dots does not change, and therefore consideration is given so that the gradation does not change. Further, since the rectangular area 3 × 3 dots configuration to be cut out, the sample pattern prepared in advance, well 2 ^9, as a memory for storing the sample pattern, available memory on the market today.

In the present embodiment, the bitmap image data expanded to N times the resolution originally possessed by the laser printer is cut out in units of N × N bit rectangular areas. The pattern of the area of the bitmap image data to be cut out has such a size and
The shape is not limited to the shape, and the shape and size of the cut-out area may be changed according to the shape of the recorded figure. In addition, it is not necessary to cut out all the bitmap image data of one page in the areas of the same shape and size, and each area of the bitmap image data of one page and further different pages have different shapes and sizes. You may make it cut out in the area | region of several patterns.

[0046]

According to the present invention, the size and position of dots to be recorded are changed after being expanded into bitmap image data having a resolution higher than that of the recording mechanism of the image forming apparatus, and With the resolution of the recording mechanism, the dots are recorded so that the area ratio of the recording dots per unit area does not change, so the contour is improved, the curve can be recorded smoothly, and the gradation can be reproduced well. Therefore, it is possible to perform recording (image formation) with excellent image quality. Furthermore, since the resolution does not change, it is possible to perform recording using the bitmap font of the recording mechanism section.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram showing a configuration of a part relating to a main part of the present invention of the image forming apparatus of one embodiment of the present invention.

FIG. 3 is a diagram illustrating a method of recording an outer peripheral portion of a circle based on bitmap image data having a triple resolution.

FIG. 4 is a diagram showing a method for determining an area and a recording position of dots to be actually printed based on the data content of a rectangular area cut out with 3 × 3 bits in the present embodiment.

FIG. 5 is a diagram showing a state of jaggies generated on the outer circumference of a circle recorded by a conventional laser printer.

FIG. 6 is a diagram illustrating a conventional method for improving image quality.

[Explanation of symbols]

 1 Bitmap image data creating means 2 Recording dot setting means 3 Recording control means

Front page continued (72) Inventor Jun Shio 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (3)

[Claims] 1. A control circuit of an image forming apparatus for expanding image data represented by vectorization into bitmap image data and recording the image data, wherein the image data represented by the vectorization is input to the image forming unit. Bitmap image data creating means (1) for expanding the bitmap image data having a resolution higher than that of the recording mechanism of the apparatus, and bitmap image data expanded by the bitmap image data creating means (1). , Sequentially cutting out in a predetermined block unit, and based on the data content in each of the cut out blocks, generates a recording dot corresponding to the resolution of the recording mechanism section, and also determines the area of each recording dot to be generated. Recording dot setting means (2) for setting area data for specifying and position data for specifying a recording position, Based on the area data and the recording position of each recording dots to be set by the recording dot setting means (2), in the area of each recording dot, it is designated by the area data,
A control circuit for an image forming apparatus, comprising: a recording control unit (3) for controlling recording at a position designated by the position data. 2. The recording dot setting means (2) sets the total area of all the recording dots to be set equal to the total area of the recording dots created by the bitmap image data creating means (1). 2. The control circuit for the image forming apparatus according to claim 1, wherein the area data of each of the recording dots is determined. 3. The image according to claim 1, wherein the recording dot setting means determines the position data of each recording dot based on the arrangement state of the recording dots in the cut block. Forming device control circuit.