JPH10258544A - Multi-beam recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely plot by using a projection lens having an aberration by forming a plotting region by a first moving means, sorting a light source into a plurality of groups parallel to a first direction, and changing a moving amount of the plotted region at the time of switching based on a second moving means perpendicular to a first direction. SOLUTION: Data from buffers 104a, 104b are respectively written in image memories 106a, 106b of an LED controller 106 via an arithmetic processor 103 and a data writer 104. In this case, in a light source part 42 where a plurality of light sources are arrayed in two-dimensional manner. Non-light emitting data is written in a partition in the memory corresponding to the group of one side and the other side not used for plotting, and plotting data is written in a partition used for plotting. The processor 103 outputs it to a moving controller 110, and plots it while moving a table in a Y direction by a table moving motor 2M. Then, an optical head is moved by an optical system driving motor 5M, and next region is plotted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention projects a light beam from a light source section having a plurality of light sources arranged two-dimensionally on a drawing surface by a projection lens, and relatively scans the light source image and the drawing surface. The present invention relates to a multi-beam recording apparatus that draws an image by causing the apparatus to draw an image.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 6-186490 has a light source unit having a semiconductor laser arrayed as a two-dimensional matrix and a corresponding aperture, and an image of this aperture is projected onto a drawing surface by a projection optical system. A multi-beam recording device that forms dots is disclosed. This apparatus controls the semiconductor laser while relatively scanning the drawing surface and the aperture image, and shifts the aperture images of each row discretely arranged in a direction orthogonal to the scanning direction by a predetermined pitch at a plurality of rows. By overlapping, a two-dimensional image is formed on the drawing surface.

[0003]

However, this type of multi-beam recording apparatus uses a large-diameter projection lens for reducing and projecting the aperture pattern on the drawing surface, so that the peripheral portion of the lens has a large aperture. The amount of aberration is relatively large, and for apertures in the peripheral part away from the optical axis, the shape of the image (dot) of the aperture projected on the drawing surface is distorted, or the position of the dot deviates from the expected position . Such distortion or displacement of the aperture image does not pose a problem when the resolution of the formed image is low, but poses a problem when the resolution is high because it hinders precise drawing.

An object of the present invention is to provide a multi-beam recording apparatus capable of performing precise drawing even when a projection lens having an aberration is used, in view of the above-mentioned problems of the prior art.

[0005]

In order to achieve the above object, a multi-beam recording apparatus according to the present invention selects a light source used for drawing from among a plurality of light sources arranged two-dimensionally, thereby obtaining a scanning width. Can be changed. According to such a configuration, when the resolution is low, a pattern can be formed in a wide range by one scan using all the light sources, and when the resolution is high, peripheral light sources distant from the optical axis of the projection optical system can be formed. By drawing using only the light source at the central portion where the influence of aberration is small without using it, a highly accurate pattern can be formed.

That is, in the multi-beam recording apparatus according to the present invention, a plurality of light sources having an effective area
A light source unit arranged in a dimension, a projection optical system for forming dots on a drawing surface by a light beam emitted from the light source, and a light source unit and a drawing surface relatively linearly moved along a first direction during a drawing period. A first moving unit for forming a band-shaped drawing area on the drawing surface, and a light source unit and the drawing surface being relatively moved along a second direction perpendicular to the first direction during a non-drawing period. The second moving means for switching the drawing area by the first moving means by moving the
Classified into multiple groups by borders parallel to the direction of,
By setting the width of the drawing area by selecting the light source used for drawing and the light source not used for each group, the light source of the group not used for drawing is not turned on,
Drawing control means for controlling light emission and non-light emission of a group of light sources used for drawing based on input drawing data;
A moving amount changing unit configured to change a moving amount of the second moving unit when the drawing region is switched according to the width of the drawing region.

The drawing control means includes an arithmetic processing circuit for forming a bit map based on input drawing data, an image memory for storing control data for all light sources corresponding to a single scanning area, A data writing circuit which writes bitmap drawing data to an image memory as control data of a group of light sources used for drawing, and writes non-light-emitting data to an image memory as control data of a group of light sources not used for drawing; It is preferable to include a light source driving circuit that drives the light source unit based on data written in the memory.

Further, in this case, the data writing circuit includes two buffers for storing the control data contained in one scanning area for each light source group, to write bitmap data and non-light emission data and to write these data. It is possible to configure so that the data output to the memory and the data output to the memory are alternately executed by the two buffers.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a multi-beam recording apparatus according to the present invention will be described below. FIG. 1 is a perspective view illustrating an appearance of the multi-beam recording apparatus 100 according to the embodiment. The multi-beam recording apparatus 100 according to the embodiment includes:
This is an apparatus for recording a circuit pattern on a mask for exposure printing for producing a printed circuit board.

In the multi-beam recording apparatus 100, an apparatus main body base 1 and a photosensitive film 3 as a drawing surface on which a circuit pattern is formed are placed.
Table 2 slidable in the direction, optical head 4 for forming a projection pattern on photosensitive film 3, and optical base for supporting optical head 4 slidably in the X direction perpendicular to the Y direction with respect to main body base 1. 5 are schematically constituted.

The table 2 has a lower surface guided along a pair of rails 2R extending in the Y direction. The table 2 is rotated by a table driving motor (not shown) to rotate the ball screw 2B to form a light source formed by the optical head 4. The photosensitive film 3 is scanned with respect to the image in the Y direction. By means of these ball screws 2B and the table drive motor, a first moving means for linearly moving the photosensitive film 3, which is the drawing surface, relative to the light source image in the Y direction, which is the first direction, during the drawing period. Be composed.

The optical base 5 is movable in the X direction by being guided by a pair of guide rails 5R extending in the X direction.
Is rotated to move the optical head 4 in the X direction. These optical system drive motor 5M and ball screw 5
B constitutes a second moving means for relatively moving the image of the light source and the drawing surface along a direction different from the Y direction. The second moving means is an optical head 4 during a non-drawing period.
Is linearly moved in a second direction (X direction) orthogonal to the first direction (Y direction) to switch the drawing area by the first moving means.

The optical head 4 is provided with a scale detection head 5D for detecting a linear scale 5K for position detection provided on the apparatus main body base 1, and an optical system drive motor 5M receives a detection signal from the scale detection head 5D. Feedback control is performed based on the feedback control. Although not shown,
The table 2 also has a similar detection mechanism, and the table drive motor is feedback-controlled based on the detection result.

FIG. 2 is a side view schematically showing an optical system of the optical head 4. The optical head 4 includes a light source section in which a plurality of light sources having an effective area are discretely arranged two-dimensionally, and a projection optical system that forms an image of the light source on a drawing surface. The light source unit includes an LED (light emitting diode) 42 as a light emitting element mounted on a printed circuit board 41, and an aperture plate 43 in which an aperture AP is formed in front of the LED 42 in correspondence with each LED 42. The projection optical system includes a first lens group 44 and a second lens group 45 arranged in order from the aperture plate 43 side and has a magnification of 1/25.
The beam transmitted through the aperture plate 43 is used to form an image of the aperture AP as dots on the surface of the photosensitive film 3.

FIG. 3 is a diagram showing the aperture panel 43 viewed from the upper surface side of the optical head 4 (a diagram viewed from the upper side to the lower side in FIG. 2) for explaining the arrangement of the apertures formed in the LED 42 and the aperture panel 43. ).
Note that the position of the LED 42 is indicated by a broken line. In the present embodiment, 2048 LEDs 42 are two-dimensionally arranged. 32 LEDs 42 are arranged in the Y direction (hereinafter, the LEDs 42 arranged in the Y direction are referred to as Y-row LEDs).
42). Similarly, 64 rows of the LEDs 42 arranged in the Y direction are arranged in the X direction. Focusing on one line in the X direction, 64 LEDs 42 are aligned in a straight line along the X direction (hereinafter, LEs aligned in the X direction).
D is called X row LED). The LED 42 has a maximum diameter of 3.8 mm on a plane parallel to the photosensitive film 3.
As shown in FIG. 3, the LEDs 42 are arranged at an interval of 4 mm in each of the X direction and the Y direction in order to arrange them so as not to contact each other. The LEDs in the Y column are sequentially arranged at positions shifted by the diameter of the aperture AP, as shown by Y1 to Y32 in FIG. 3, and the aperture AP is also formed in a similar arrangement. The distance between Y1 and Y33 is 4m
m, the diameter of the aperture AP is 0.125 mm.

FIG. 4 is a view showing dots corresponding to each beam on the photosensitive film 3, ie, an image of the aperture panel 43. The black dots in the figure are dots on which the film 3 is exposed by the beam. FIG. 4 is a diagram showing the arrangement of dots, and the size of each part is not shown on the correct scale. The formation range of the dots on the photosensitive film 3 is 10.24 mm in the X direction and 4.96 mm in the Y direction.

At the time of drawing, the light emission of the LED is controlled while moving the table 2 in the Y direction so that the Y
An image is formed in a band-like region extending in the direction. Thus, when focusing on a certain line (a line along the X direction), the images (dots) of all the LED beams are arranged in a line at a pitch of 5 μm between the centers in one scan. All LE
If D is used for drawing, a 10.24 mm wide strip-shaped drawing area is formed on the photosensitive film 3 by scanning the table. However, in the apparatus of the embodiment, the width of the band-shaped drawing area can be changed.

In order to change the width of the drawing area,
To select the LED used for drawing, all LEs
D is classified into a plurality of groups by a boundary line in the Y direction. The classification is changed according to the resolution based on 8 MB, which is the minimum unit of drawing data that can be processed by the processing device at one time. The device of the embodiment is configured so that the resolution can be selected between a standard density of 5 μm between dots and a double density of 2.5 μm.

In the case of the standard density, one band-like area is drawn by one scan as described above. In this case, the light emission timing of each LED is determined so that the dot pitch is also 5 μm in the Y direction. At the standard density, the data amount of one scan is 32 MB (megabyte), and the data capacity of 8 MB is equivalent to 16 columns of Y columns, that is, 3 MB.
2 × 16 = 512 LEDs can be controlled for one scan. Therefore, in this case, the LEDs are classified into four groups G1 to G4. Of these groups, one of the center groups G2 and G3 is always used for drawing, and the outer groups G1 and G4 are used for drawing or not depending on selection. Therefore, ten combinations of A to J shown in Table 1 below can be considered. In Table 1, groups to be used are indicated by ○, groups not used are indicated by ×, and the number of light source groups not used for drawing is indicated by numbers m and n. Here, m is the number of light source groups not used for drawing on one side in the width direction of the drawing area, and the m-th group from the outside is not used for drawing. Similarly, n is the number of light source groups that are not used for drawing on the other side in the width direction of the drawing area.

[0020]

[Table 1] Group ABCDEFGHIJG1 ○ × ○ × ○ × × × × × G2 ○ ○ ○ × ○ ○ ○ × × × G3 ○ ○ ○ ○ × ○ × ○ × × G4 ○ × ○ × × × × × ○ ○

When a high drawing accuracy is required for changing the drawing width, only the light passing through the center of the projection lens is used instead of the light that uses the region outside the projection lens where the influence of aberration is large. The first purpose of doing and any LED
When light emission becomes impossible due to disconnection or the like,
A second object is to prevent missing dots by drawing without using a group including ED. First
In order to achieve the above object, it is necessary to draw using only the LED corresponding to the central region without using the LED corresponding to the region outside in the width direction. In this case, it is sufficient if two combinations of A and F can be selected.
However, in order to achieve the second object, other B to E,
It is desirable that a combination of G to J can be selected.

When drawing at a standard density, the photosensitive film 3
When an image is formed in a band shape from the end in the Y direction to the other end of the drawing area of the drawing area, the optical head 4 is moved in the X direction by the drawing width corresponding to the number of the groups used. Then, by moving the table 2 in the opposite direction (along the Y direction) from the previous time after the movement of the optical head 4,
Similarly, a band-shaped image extending in the Y direction is formed on the photosensitive film 3 adjacent to the previously formed region. In the case of the standard density, the optical head is 10.24- (m + n) .times. Each time scanning is completed, regardless of whether the table scans in any direction.
It is sent in the 2.56 mm X direction.

On the other hand, in the case of double density, after scanning in one direction, the head is moved in the X direction by half a pitch, that is, 2.5 μm, and scanning is performed in the opposite direction, thereby forming the image by the previous scanning. The gap between the dots is filled with dots. In this manner, a pattern is drawn in one band-shaped area by reciprocating scanning by an interlace method with a half pitch shift. When all the LEDs are used for drawing, data can be drawn at a density of 4096 dots for a width of 10.24 mm. 2.5 μm also in the scanning direction
When dots are formed at a pitch, the data amount of one round trip scan is 128 MB, which is four times the standard density, and a data capacity of 8 MB is equivalent to four Y columns, that is, 32 × 4 = 128 Ls.
The ED can be controlled for the reciprocating scanning. When double-density recording is performed, it is equivalent to controlling 4048 LEDs in one scan when viewed from the side where the drawing data is sent. In view of this, 8 columns of Y columns with a data capacity of 8 MB are considered. Minutes,
That is, 32 × 8 = 256 LEDs are controlled for one scan.

In the case of double density, the LEDs are classified into 16 groups g1 to g16. In this case, 136 combinations are conceivable to achieve the second object. However, assuming that the center of the light source unit and the optical axis of the projection lens coincide with each other, it is only necessary to select eight combinations of a to h shown in Table 2 below for the first purpose. .

[0025]

[Table 2] Group abcdeffghg1 ○ × × × × × × × g2 ○ ○ × × × × × × g3 ○ ○ ○ × × × × × g4 ○ ○ ○ ○ × × × × g5 ○ ○ ○ ○ ○ × × × g6 ○ ○ ○ ○ ○ ○ × × g7 ○ ○ ○ ○ ○ ○ ○ × g8 ○ ○ ○ ○ ○ ○ ○ ○ g9 ○ ○ ○ ○ ○ ○ ○ ○ g10 ○ ○ ○ ○ ○ ○ ○ × g11 ○ ○ ○ ○ ○ ○ × × g12 ○ ○ ○ ○ ○ × × × g13 ○ ○ ○ ○ × × × × g14 ○ ○ ○ × × × × × g15 ○ ○ × × × × × × g16 ○ × × × × × × × m 0 1 2 3 4 4 5 6 7 n 0 1 2 3 4 4 5 6 7 Drawing width (mm) 10.24 8.96 7.68 6.40 5.12 3.84 2.56 1.28

When the center of the light source unit does not coincide with the optical axis of the projection lens, the unused area is not only symmetrical (m = n) but also asymmetrical (m ≠ n) as shown in Table 2. May be determined. For example, if m = 2 and n = 1, the group g
You can choose not to use 1, g2, g16.

In the case of drawing at double density, when an image is formed in a belt shape by reciprocating scanning from the end in the Y direction of the drawing area of the photosensitive film 3 to the other end, the optical head 4 is used as described above. It moves in the X direction by the drawing width according to the number of groups. Then, by moving the table 2 along the Y direction after the movement of the optical head 4, similarly,
A belt-shaped image extending in the Y direction is formed on the photosensitive film 3 adjacent to the previously formed region. In the case of double density, the optical head is sent in the 2.5 μm X direction every time the table is scanned when the table scans in one direction, and every time the table is scanned in the other direction. 10.24- (m +
n) × 0.64 mm Sent in the X direction.

FIG. 5 is a block diagram showing a control system of the recording apparatus 100 of the embodiment. The recording apparatus 100 is connected to the workstation WS via an Ethernet network, and exposes and draws a pattern on the photosensitive film 3 according to the drawing data and control information sent from the workstation WS. Workstation WS
Is control data including the pitch between dots, that is, the resolution and the numbers m and n of the light source groups not used for drawing.

The control system of the drawing apparatus 100 includes a data input interface (I / F) 101 for receiving data from the workstation WS input via the Ethernet.
And a buffer 102 having a capacity for storing the entire image data of one image input as vector data via the input interface, and converting the vector data written in the buffer 102 into bitmap raster data. The arithmetic processing circuit 103 and the arithmetic processing circuit 10
2. Two buffers 1 each having a capacity of 8 MB, in which bitmap data converted by 3 are written alternately.
Data writing circuit 104 including data lines 04a and 104b
And a bit inversion processing circuit 105 for non-inverting or inverting the bits of the drawing data depending on whether the image formed on the photosensitive film 3 is a positive image or a negative image, and drawing data of one band-like region formed by scanning. 1 to hold
Two image memories 106a and 106 each having a capacity of 28 MB
6b, and a light source control circuit 106 for controlling light emission of the LED of the optical head 4.

The unit of drawing data input from the workstation WS covers the entire area. This entire area is covered by combining a plurality of band-shaped areas formed by scanning the table 2. Buffer 10
2 stores the drawing data for the entire area.

The arithmetic processing circuit 103 writes the converted data alternately in the two buffers 104a and 104b,
The data writing circuit 104 outputs to the light source control circuit 106 the data in one buffer, for which the data transfer from the arithmetic processing circuit 103 has been completed, while the data from the arithmetic circuit 103 is transferred to the other buffer. The drawing data output from the arithmetic processing circuit 103 is defined such that, for example, the dot corresponding to the position where the conductor pattern of the printed board is formed on the photosensitive film is “1”, and the other areas are “0”. This is binary data based on a positive image, and the light source control circuit 106 causes the LED to emit light for a dot with data “1” and does not emit light for a dot with data “0”.

If the image to be formed is a positive image, the bit inversion processing circuit 105
4 is transmitted to the LED control circuit 106 as it is, and in the case of a negative image, the data bit is inverted, that is, the dot of “1” is changed to “0”,
The dot “0” is inverted to “1” and transmitted.

The arithmetic processing circuit 103 has not only a function of converting data as described above, but also a function as a CPU for controlling other circuits. Further, the arithmetic processing circuit 103 has a function of calculating the amount of movement between the table 2 and the optical head 4 based on the scanning width determined based on the group numbers m and n and the position information included in the rendering data. The movement amount data thus obtained is output to the movement control circuit 110. The movement amount control circuit 110 converts the table AC servo circuit 111 and the optical head servo circuit 1
Then, the optical system driving motor 5M and the table moving motor 2M are driven via the motor 12 to move the optical head and the table. During driving, the outputs of the scale detection heads 5D and 2D are input to the movement amount control circuit 110,
Each of the motors 5M and 2M is feedback-controlled based on the detected movement amount.

FIG. 6 is an explanatory diagram showing a memory space of the image memory 106a included in the control system. In the case of the standard density, as shown in FIG. 6A, an area called a 32 MB band used for one scan is constituted by four areas called partitions divided into 8 MB. With this 32 MB of drawing data, 2048 LEDs are controlled in one scan at the standard density. One partition has drawing data for one-scan control of 512 LEDs, and each partition corresponds to each of the groups G1 to G4 of the LEDs.

On the other hand, in the case of double density, as shown in FIG. 6B, a 128 MB band used for reciprocal scanning is constituted by 16 partitions divided into 8 MB. In this case, one partition is 128
The drawing data necessary for reciprocally scanning the LEDs is held, and each partition is composed of a group of LEDs g1 to g1.
Corresponds to 6.

The data writing circuit 104 alternately outputs data from the two buffers 104a and 104b and writes drawing data in units of partitions to the LED control circuit 106.
Is written to the image memories 106a and 106b. Note that not using a specific group of LEDs for drawing is equivalent to inputting data “non-light emitting” for all dots that can be formed by these LEDs. Therefore,
According to the numerical values of m and n, the partition where the data corresponding to the unused light source group is written is not the drawing data input from the arithmetic processing circuit 103,
Certain data meaning "non-light emission" is written. However, since the data output from the data writing circuit 104 is inverted by the bit inversion circuit 105 when the image to be formed is a negative image, the data written to the image memories 106a and 106b is " In the case of a positive image, all bits of the buffers 104a and 104b to be transferred to the corresponding partition are filled with "0" so as to be "0" meaning "non-light emission", and in the case of a negative image, Filled with "1".

FIGS. 7 and 8 are flowcharts showing a control procedure by the arithmetic processing circuit 103 for drawing a pattern for one screen. Here, a case where recording is performed at double density, that is, a case where one band is composed of 16 partitions will be described as an example. When control information and drawing data are received from the workstation WS in steps (indicated by "S." in the drawing) 1 and 2, initializing of the optical head 4 and the table 2 is performed in step 3 based on positional information included in the drawing data. Movement control circuit 1 for finding position
Output to 10 The movement control circuit 110 determines the optical system drive motor 5M and the table movement motor 2M based on this information.
And drive.

In step 4, the number of light source groups m and n not used for drawing is subtracted from the total number of groups 16 to obtain the number p of light source groups used for drawing. In the case of the standard density, p is obtained by (4-mn). In steps 5 to 10, data of "non-light emission" is written to m partitions in the image memory corresponding to the one light source group not used for drawing. As described above, the data of “non-emission” is “0” when a positive image is formed and “1” when a negative image is formed, so a corresponding value is written.

Steps 11 to 14 are processes for writing drawing data to partitions on the image memory corresponding to the groups of light sources used for drawing. In the subsequent steps 15 to 20 of FIG. 8, "non-light emitting" data is written to n partitions on the image memory corresponding to the other light source group not used for drawing.

By the above processing, one of the image memories 106a
When data for double-density reciprocal scanning is written in the area of 28 MB, in step 21, the LED is controlled to emit light while the table is moved in the Y direction to draw a pattern. 1
When the drawing for the two band-shaped drawing areas is completed, if the drawing data remains, the optical head 4 is moved in step 23 and returns to step 5 in FIG. 7 to start drawing the next band-shaped drawing area. . When the drawing data ends, drawing for one screen ends. In this flowchart, the actual drawing process in step 21 and the writing of data to the image memory in steps 5 to 20 are shown to be executed in chronological order, but are stored in one image memory 106a. While the pattern is being drawn by the drawn drawing data, the drawing data is written to the other image memory 106b. As a result, it is possible to reduce the time required to start drawing from one band-shaped drawing region to the next region.

[0041]

As described above, according to the present invention, drawing is performed by using only the central light source without using a light source distant from the optical axis where aberration of the projection optical system greatly affects. The position accuracy of the dots formed by the light beams from the respective light sources can be improved, and high-accuracy drawing can be performed without increasing the performance of the projection optical system. In addition, when a part of the plurality of light sources cannot emit light due to disconnection or the like,
Drawing can be performed without using the light source group including the light source, and the apparatus can be used even before the optical head is repaired or replaced.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an appearance of a multi-beam recording apparatus according to an embodiment.

FIG. 2 is a side view schematically showing a configuration of an optical head.

FIG. 3 is a diagram of the aperture panel viewed from the upper surface side of the optical head.

FIG. 4 is a view showing a pattern of a point image formed on a photosensitive film.

FIG. 5 is a block diagram illustrating a control system of the apparatus according to the embodiment.

FIG. 6 is an explanatory diagram showing a memory space of an image memory included in the LED control circuit.

FIG. 7 is a flowchart showing the first half of the procedure of control of the arithmetic processing circuit.

FIG. 8 is a flowchart showing the latter half of the control procedure of the arithmetic processing circuit.

[Explanation of symbols]

 2 Table 4 Optical head 42 LED 43 Aperture plate 44, 45 First and second lens groups (projection optical system) 100 Pattern recording device 103 Arithmetic processing circuit 104 Data writing circuit 104a, 104b Buffer 106 Light source control circuit 106a, 106b Image memory

Claims (7)

[Claims] A light source section in which a plurality of light sources having an effective area are discretely two-dimensionally arranged; a projection optical system for forming dots on a drawing surface by a light beam from the light source; A first moving unit that relatively linearly moves the light source unit and the drawing surface along a first direction to form a band-shaped drawing region on the drawing surface; and the light source unit during a non-drawing period. A second moving unit that switches a drawing area by a first moving unit by relatively moving the drawing surface along a second direction perpendicular to the first direction; and the light source unit. The light sources are classified into a plurality of groups by a boundary line parallel to the first direction, and the width of the drawing area is set by selecting a light source used for drawing and a light source not used in each group, Group of light sources not used for drawing Drawing control means for controlling light emission and non-light emission of a group of light sources used for drawing based on input drawing data without lighting, and a drawing area by the second moving means in accordance with a width of the drawing area And a moving amount changing means for changing a moving amount at the time of switching. 2. An image processing apparatus according to claim 1, wherein said drawing control means includes a processing circuit for forming a bitmap based on input drawing data, and an image storing control data for the total number of said light sources corresponding to a single drawing area. Memory, and write the bitmap drawing data to the image memory as control data of a group of light sources used for drawing,
A data writing circuit for writing non-emission data as control data of a light source in a group not used for drawing to the image memory, and a light source driving circuit for driving the light source unit based on the data written to the memory. The multi-beam recording apparatus according to claim 1, wherein: 3. The data writing circuit includes two buffers for storing control data included in one drawing area in units of the light sources, and writing the bitmap drawing data and the non-light emitting data. 3. The multi-beam recording apparatus according to claim 2, wherein said two buffers alternately execute and discharge of said data to said image memory. 4. The multi-beam recording according to claim 2, wherein the number of light sources included in the group is changed according to the size of drawing data necessary for controlling the light sources in the group. apparatus. 5. The multi-beam recording according to claim 1, wherein the drawing control unit selects one or more groups outside at least one of the light source groups as a group not used for drawing. apparatus. 6. The drawing control unit according to claim 5, wherein the same number of groups on both sides of the light source group are selected as groups not used for drawing.
2. The multi-beam recording apparatus according to claim 1. 7. An image is drawn by projecting a light beam from a light source unit having a plurality of light sources arranged two-dimensionally on a drawing surface by a projection lens and relatively scanning the light source image and the drawing surface. A multi-beam recording apparatus, wherein a scanning width can be changed by selecting a light source used for drawing.