JPH02131956A - Method and apparatus for exposure of image - Google Patents

Abstract

PURPOSE:To cancel density irregularity by so regulating exposure amount in response to the interval of adjacent main scanning lines as to cancel density irregularity caused by the positional deviations of the main scanning lines formed on a recording material generated in a sub scanning direction. CONSTITUTION:A controller 20 has a microprocessor (muP) 54 for calculating scanning positional deviation and writing density. The muP 54 receives the conveying speed information of a recording material 40 from a rotary encoder 52 for forming conveying position deviation detecting means to detect the deviation. The density correction amount of a raster to be written this time is determined on the basis of raster interval or scanning positional deviation, density information of raster 68a immediately before a RAM 60, density information of raster 68c to be written next time from a RAM 62 and reflectivity information of used mirror face of a polygonal mirror 16 from a ROM 58.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rask scan type image exposure method and an apparatus thereof, and more particularly, to an image exposure method using a rask scan method and an apparatus therefor. The present invention relates to an image exposure method and apparatus capable of canceling out 4 degree unevenness caused by a shift in rask interval caused by unevenness.

<Prior art> The rusk scan method, which is a scanning method used in television picture tubes, etc., is used to scan text, pictures, photographs, videos, and other images onto recording materials such as paper and film. It is used in an image exposure device of an image recording device to obtain a visible image. This Rusk scan method is also called the TV scan method, and it scans the screen sequentially in one dimension.
For example, there is a scanning method in which main scanning is performed from left to right and sub-scanning is performed in a direction substantially perpendicular to the main scanning direction, for example, from top to bottom.

Conventionally, in an image recording apparatus using this Rusk scan method, a solid laser such as a semiconductor laser (LD), a laser light source such as a gas laser and a liquid laser, a light emitting element such as a light emitting diode (LED), a mercury lamp, a mercury lamp, etc.
A light source such as a xenon lamp or a sodium lamp is used, and the light beam emitted from such a light source carries image information and is deflected one-dimensionally by a light deflector such as a polygon mirror or galvanometer mirror to perform main scanning. At the same time, a recording material such as a photoreceptor or a photosensitive material is conveyed by a sub-scanning conveyance means in a direction substantially perpendicular to the main scanning direction, sub-scanned and exposed two-dimensionally, and finally onto paper, film, etc. Obtaining a dimensional visible image.

Therefore, a large number of parallel main scanning lines are defined on the recording material by the deflection of the optical deflector at regular intervals in the sub-scanning direction, thereby forming an M-pattern rask with a prescribed interval.

<Problems to be Solved by the Invention> By the way, an image exposure device that uses a light deflector such as a polygon mirror or a galvanometer mirror for main scanning and conveys a recording material as sub-scanning for one line (one line).
In an image exposure apparatus in which it is difficult to change the writing timing of the light beam, the light beam may be The image position shifts, causing irregularities in the rask spacing.

For example, as shown in FIG. 4, when the distance between the rusks becomes irregular, areas where the rusks are closely spaced appear dark, and areas where the rusks are far apart appear light. Therefore, when an exposed image with pitch unevenness (irregularity) in the rask interval is used as a visible image, density unevenness occurs in the image, which significantly reduces the image quality of the visible reproduced image.
I was supposed to be a member. If you line them up, set the rask interval to 1
/ 16 mm, and if the number of polygon mirrors is 8, it will be 0.5 m if the face tilt correction is not perfect.
M pitch unevenness appears. This density unevenness of 0.5 mm is most noticeable on the recording material and becomes a major problem in image purchasing.
Furthermore, if there is unevenness in the reflectance of the reflective surface of the optical deflector, unevenness in density will occur in the main scanning line itself, which, combined with unevenness in rask intervals, will likely cause unevenness in density in the reproduced image.

Incidentally, if the above-mentioned irregularities in rask intervals (intervals between main scanning lines), irregularities in the density of main scanning lines, or the combination thereof exceed a certain amount, it will be recognized as density unevenness on the reproduced image.

Therefore, in the past, in order to eliminate these density unevenness, the machining accuracy, operation accuracy, and assembly of optical deflectors such as polygon mirrors and galvanometer mirrors have been improved in order to suppress uneven rask intervals and uneven density to below a certain amount. Measures to improve accuracy have been taken, such as increasing the accuracy, increasing the accuracy of the optical system for surface tilt correction to increase the amount of correction, and improving the feeding accuracy of the recording material conveyance system, especially the sub-scanning withdrawal means.

By the way, if there is an irregularity in the rask spacing, the rotation of the optical deflector such as a polygon mirror or galvanometer mirror and the conveyance of the recording material may be controlled, for example, if the recording material is not conveyed to the next rask writing position. The writing timing can be varied by stopping the rotation of the optical deflector, and conversely, stopping the recording material when the optical deflector is delayed even though it has been transported to the next rask writing position. However, this method requires a more complex and expensive control system than the method of making the rask interval constant, and is difficult to implement.

Not only is there a limit to improving the accuracy of such optical deflectors and sub-scanning conveyance means, but also it is necessary to use expensive devices and parts to improve the accuracy, which significantly increases costs. In addition, if you are aiming for a low-cost device,
There were limitations to using such a method. An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a special method when performing two-dimensional exposure using a raster scan method that uses main scanning of a light beam by an optical deflector and sub-scanning by conveying a recording material. There is no need to use an expensive optical deflector or sub-scanning conveyance means with high precision, and irregularities in rask intervals (intervals between main scanning lines) caused by surface inclination of the optical deflector and/or uneven feeding of the recording material can be avoided. To provide an image exposure method and an apparatus for the image exposure method, which can cancel the density unevenness by adjusting the exposure amount according to the irregularity of the rask interval, thereby adjusting the density of each main scanning line, and making it unrecognizable. It is something to do.

Means for Solving the Problems> In order to achieve the above object, the present invention performs main scanning by sequentially irradiating a recording material with a light beam in a one-dimensional direction, and also performs main scanning by sequentially irradiating a recording material with a light beam in a one-dimensional direction. When the recording material is conveyed in the sub-scanning direction to perform sub-scanning and the recording material is exposed two-dimensionally, the problem is caused by a positional shift of the main scanning line defined on the recording material that occurs in the sub-scanning direction. The present invention provides an image exposure method characterized by adjusting the exposure amount according to the interval between adjacent main scanning lines so as to cancel density unevenness.

Further, the present invention performs main scanning by sequentially irradiating the recording material with a light beam in a one-dimensional direction, and performs sub-scanning by conveying the recording material in a direction substantially perpendicular to the main scanning direction.
An exposure apparatus that exposes the recording material two-dimensionally, comprising: at least one light source that irradiates the light beam; a light deflector that deflects the light beam in a one-dimensional direction; a sub-scanning 12 feeding means for detecting the surface of the recording material; a means for detecting the amount of surface tilt of the optical deflector; Based on the amount of surface tilt and/or the conveyance positional deviation of the recording material detected by the detection means, the immediately preceding main scanning line is The present invention provides an image exposure apparatus characterized in that it has a control unit that calculates an interval from the main scanning line and adjusts the exposure amount based on the interval and at least the density of the immediately preceding main scanning line.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The image exposure method and apparatus thereof according to the present invention will be explained in detail below based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a perspective explanatory diagram including a flow of a control system of an embodiment of an image exposure apparatus of the present invention. As shown in the figure, the image exposure apparatus IO of the present invention basically includes a light source section 12,
The light source section 12 constituting the optical system includes a surface tilt correction optical system 14, a polygon mirror 16, a sub-scanning conveyance means 18, and a control section 20 that controls the image exposure method of the present invention. The correction optical system 14 and the polygon mirror 16 are placed on a surface plate (not shown).

Since the image exposure apparatus 10 of the present invention is capable of color image exposure, the light source section 12 is equipped with three colors, for example, yellow (Y).
light source 22Y for magenta (M), light source 22M for magenta (M), cyan (
C) light source 22C and its driving source (driver) 24Y,
24M, 24C, and a reflecting mirror 28Y that reflects the light beam 23Y emitted from the Y light source 22Y in a predetermined direction.
A dichroic mirror 26M transmits at least the light beam 23Y from the Y light source 22Y and reflects the light beam 23M from the M light source 22M in the same direction; Dichroic mirror 26 that reflects the light beam 23C from 22C in the same direction
C, reflective mirror 26Y1 dichroic mirror 26M,
26C, light beams 23Y, 23M. A collimator lens 28 that adjusts the beam diameter of the light beam 27 in which 23C is combined into one, a cylindrical lens 30 for correcting surface tilt, and a reflecting mirror 32 that reflects the light beam 27 toward the mirror surface 16a of the polygon mirror 16. It consists of In the example shown in FIG. 1, three color light sources 22Y, 22M, 22C and their drivers 24Y, 2 are used for color image exposure.
4M. 24C, and a reflecting mirror 26Y1 for combining light beams 23Y, 23M, and 23C emitted from three color light sources 22Y, 22M, and 22C into one dichroic mirror 26.
M, 26C are provided, but in the case of monochrome image exposure, only one set of the light source, its driver, and reflection mirror is required.

The polygon mirror 16 is an optical deflector for deflecting the light beam 27 in one-dimensional direction, and has a plurality of mirror surfaces 16a. In the example shown in Figure 1, a polygon mirror 16 consisting of eight mirror surfaces is rotated at a constant speed by a drive source 34 such as a motor. The rA power source 34 has a polygon mirror 1.
An encoder 35 for controlling the rotation of 6 is attached. In the present invention, the information of this encoder 35 is used to control the polygon mirror 16 used for scanning exposure.
It detects which of the eight mirror surfaces 18a of the polygon mirror 16 is, and detects the amount of surface tilt of the mirror surface 16a of the polygon mirror 16. In the present invention, a polygon mirror 1 is used as an optical deflector.
6, any optical deflector can be used as long as it can deflect one light beam in one dimension, for example, one that uses a rotating mirror or one that uses a rotating mirror that swings. A galvanometer mirror can be used. A light beam 27 deflected in one dimension by the polygon mirror 16 is deflected from 27a to 27b, and the deflected light beams 27a to 27b are passed through a scanning lens 36 such as an fθ lens.
is transmitted and reflected by the concave cylindrical mirror 38,
The optical system is configured so as to form one main scanning line 42 on the recording material 40 that is lowered and transported by the sub-scanning transport means 18 . Here, the main scanning line 42 defines one rask.

At this time, the cylindrical lens 30 and the cylindrical mirror 38 constitute a surface tilt correction optical system 14 that corrects the scanning position shift caused by the surface tilt of the mirror surface 16a of the polygon mirror 16. The light beams 27a to 27b deflected by the polygon mirror 16 are focused onto the surface of the recording material 40.

The sub-scanning conveyance means 18 may be of any type as long as it conveys the recording material 40 in the main scanning direction, that is, in the sub-scanning direction substantially perpendicular to the main scanning line 42, and may be any suitable one depending on the form of the recording material 40. You can use anything. For example, when the recording material is a photosensitive drum, or when a sheet-like photosensitive material is used wound around a drum, the photosensitive drum or the drum itself constitutes the sub-scanning conveying means 18. If the recording material is a sheet-like photosensitive material, it can be constructed using a belt conveyor or two pairs of rollers as shown in FIG.

The sub-scanning conveying means 18 shown in FIG.
4a and 44b and 46a and 46b, and supports and conveys a sheet-shaped recording material 40. A synchronous belt 48 is suspended on one side of the lower rollers 44a and 46a of the two roller pairs, and is synchronously driven by a drive source 50 attached to the other side of the roller 44a.
The recording material 40 is conveyed at a constant speed.

Of course, if the diameters of rollers 44a and 46a are equal, these rollers 44a and 46a rotate at a constant speed.

The drive source 50, as shown in FIG.
Although it is attached to the roller 44a of the two roller pairs constituting 8, it is not limited to this example, and may be attached to any roller, and it may not be directly connected to these rollers,
The two pairs of rollers may be driven via transmission means such as belts, chains, gears, etc. A rotary encoder 52 for detecting the rotational speed of the roller 44a, that is, the conveyance speed of the recording material 40, is attached to the synchronous belt 48 side of the roller 44a. The rotary encoder 52 is preferably installed at the driving side roller 44a or 46a, but is not limited to the example shown in FIG. 1, and may be at the shaft end of any of the two roller pairs.
It may be attached to the shaft end of the drive source 50.

In the present invention, the rotary encoder 52 detects uneven conveying speed of the sub-scanning conveying means 18, that is, the rollers 44a, 46
This constitutes a conveyance position deviation detection means for detecting a conveyance position deviation of the recording material 40 due to rotational speed unevenness of a.
Here, the conveyance position deviation detection means is the sub-scanning conveyance means 1.
The rotary encoder 52 is not limited to the rotary encoder 52 attached to either of the two roller pairs constituting the roller 8, but a rotary encoder that is originally built into a drive source such as a motor may be used. The control unit 20 is the most characteristic part of the present invention, and as shown in FIGS. ROM 56 and polygon mirror 1.
The reflectance information of each mirror surface 16a of 6 is memorized (ROM5
8, a RAM 60 that stores the density information or position and density information of the raster 68a defined on the immediately previous main scanning line, and a RAM 62 that stores the density of the raster 68C on the main scanning line to be written next time. The original density information before correction of the raster 68b on the main scanning line to be written is stored (R
AM64 and RAM64 add the density correction amount from μP54 to the density information before current write correction, modulate the corrected density information used to actually write the current raster 68b, and calculate each color. It consists of 1,000 exposure adjustment stages 66 that output an exposure amount electrical signal.

μP 54 receives transport speed information of the recording material 40 from a rotary encoder 52 constituting transport position deviation detecting means, detects transport position deviation, and further detects the transport position deviation of the polygon mirror 1.
Based on the information on the used mirror surface from the encoder 35 of the drive source 34 of No. 6, the surface tilt amount of the used mirror surface is read from the ROM 56, and the previous raster 68a and the raster 6 to be written this time are
8b, that is, the scanning position deviation of the current raster 68b, and calculates the raster interval or scanning position deviation, the density information of the immediately preceding raster 68a from the RAM 60, and the raster 68 to be written next time from the RAM 62.
Density information of C and polygon mirror 1 from ROM58
Based on the reflectance information of the mirror surface used in step 6, determine the density correction amount of the rask to be written this time. The density correction amount determined by μP54 is stored in the RAM 6 in the exposure amount adjustment means 66.
The density to be written this time after correction is determined by adding it to the current original density before correction read from 4, and modulates it into an exposure amount electric signal for each color.
M, 24C.

The density correction method, that is, the exposure amount adjustment method performed in the image exposure method according to the present invention will be explained with reference to FIG. As shown in FIG. 2(a), when the immediately preceding raster 68a, the raster 68b to be written this time, and the raster 6Bc to be written next are equally spaced, no density correction or exposure amount adjustment is performed. For example, if the densities to be written on the rasters 68a, 68b, and 68c are equal, the exposure amounts will also be equal, and the densities actually written will also be equal. However, as shown in FIG. 2(b), the raster interval between the previous raster 68a and the current raster 68d is close, and the raster 68a
If the interval between d and the next raster 68e is far, the density of the raster 68d becomes lighter than the density that should be written, depending on the interval and the density of the rasters 68a, 68d, 68e, and the density of the next raster 68e. The density is corrected and the exposure amount is adjusted so that it becomes darker than the density that should be written. Conversely, as shown in FIG. 2(C), if the interval between the immediately preceding raster 68a and the current raster 68f is large, and the interval between the current raster 68f and the next rask 68g is small, the density of the rask 88f is increases, rusk 6
The concentration of 8g is reduced.

For example, the concentration that should be written is rusk 688-68g.
Assuming that the corresponding rusks are equal, the relationship between the actually written densities is as follows.

D aaa < D 6ab + D eae
> D 6acD 6ar > D aab ,
D ear < D aac where DR is raster R
Indicates the concentration of

In the image exposure apparatus shown in FIG. 1, the beam intensity of the combined beam 27 is Q. Monochromatic exposure was performed at a color density of 0.8 with a beam diameter of 01 mW, a beam diameter of 70 x 90 μm, and a raster bit of 60 tlm.

Here, as shown in Figure 2(a), the rask interval is set to 10
When it is 0%, the raster spacing becomes as shown in FIG. 2(b), and the spacing between raster 68a and raster 68d is 99%, and the spacing between raster 68d and raster 68e is 101%.
If each rask is written at a position such that The density was uneven.

Therefore, as in the image exposure apparatus 10 of the present invention, in order to perform density correction, the beam intensity is set to 98% in order to decrease the writing exposure amount of the raster 68d, and the beam intensity is set to 98% in order to increase the writing exposure amount of the raster 68e. When the exposure amount was adjusted to 102%, the density change was 0.02%.
9 (P-P), and the density unevenness was halved. As described above, in the present invention, the writing exposure amount is adjusted by adjusting the beam intensity according to the rask interval, that is, the interval between main scanning lines. , may be determined as appropriate depending on the recording material used, the light source, etc.

In the example shown in FIG. 1, the concentration correction amount is determined by μP54,
Although the exposure amount adjusting means 66 is configured to determine the current writing density, it may be configured such that the μP 54 directly determines the current writing density.

In the ROM 56, the amount of surface tilt of the mirror surface of the polygon mirror 16 that exists after being corrected by the tilt correction optical system 14 while installed in the image exposure apparatus 10 is measured and stored in advance. Similarly, the measured reflectance is stored in the ROM 58 in advance when the image exposure apparatus 10 is installed.

Here, the encoder 35 of the polygon mirror 16 that detects the mirror surface to be used and the RO that stores the amount of surface tilt of each mirror surface in advance.
M56 constitutes means for detecting the amount of surface tilt of the mirror surface 16a of the polygon mirror 16.

Although the encoder 35 of the polygon mirror 16 is used as the mirror surface detection means in the example shown in FIG. 1, the present invention is not limited to this. For example, as shown in FIG. Direct means for detecting a specific surface of the polygon mirror 16 or indirect means for detecting a predetermined position of a rotary plate coaxially rotating with the polygon mirror 16 as shown in FIG. 3b can be used. In addition, any means that can detect the mirror surface of the polygon mirror 16 may be used.

In FIG. 3a, the used mirror surface detection means 70 generates pulses at a detected portion 7l provided or attached at a predetermined position on the upper surface of a predetermined mirror surface 16g of a polygon mirror 16, and at a detected portion 71. In the case of the figure, there are eight mirror surfaces, but the mirror surface two after the detection mirror surface lag is detected as the used mirror surface 16a. Of course, the detected portion 71 may be provided on the upper surface of the used mirror surface 18a in the figure, and direct detection may be performed. Here, as the backup 72, an electromagnetic pickup, a photosensor consisting of a light-emitting light-receiving element, an electrostatic pickup, or the like can be used. When using a 6m electric pickup, the detected part 71 is made of a non-magnetic material if the predetermined portion of the upper surface of the polygon mirror 16 to be detected is a magnetic material, and vice versa. It can be used as a material. Roughly speaking, in the case of a photosensor, the detected portion 71 and a predetermined portion of the upper surface of the polygon mirror 16 may be configured to have different light reflectances. In addition, various non-contact pickups can be used.

In FIG. 3b, the used mirror surface detection means 74 is a means for indirectly detecting the used mirror surface, and is a means for indirectly detecting the used mirror surface.
6, a slit 76 opened at a predetermined position of the rotating disk 75, and a light emitting element 77a and a light receiving element 77b provided above and below the slit 76 via the rotating disk 75. It is composed. Even if the position of the slit 76 corresponds to the used mirror surface 16a in the figure,
It may be provided at any position as long as the positional relationship with the used mirror surface 16a is clear.

In the present invention, it is only necessary to detect the surface used for writing the first line or one of the first lines of the recording material shown in FIG.
As shown in the figure, only one mirror surface position may be detected, but the present invention is not limited to this, and may be configured to be able to detect a plurality of mirror surface positions. Of course, all mirror surfaces may be configured to be detected so that the surface used for writing in the first row is reliably detected in any case.

In the example shown in FIG. 1, both the means for detecting the amount of surface inclination of the polygon mirror 16 and the means for detecting the deviation in the conveyance position of the recording material 40 by the sub-scanning conveyance means 18 are reduced, but the surface inclination is sufficiently corrected. If the amount of surface inclination is small, or if the sub-scanning conveyance means 18 has high conveyance accuracy and conveyance position deviation is small, it may be configured to detect only the side that causes the scanning position displacement.

In the example shown in FIG. 1, the current writing raster 68b
Although the density correction amount is calculated from the scanning position deviation or the rask interval, the immediately preceding raster 68a, and the next writing raster 68c, it may be calculated only from the scanning position deviation or the rask interval. Even if the correction is based only on the rask interval, some density unevenness can be removed. Further, in the example shown in FIG. 1, the density correction is performed and the exposure amount is adjusted by taking into account the reflectance information of the mirror surface used in the polygon mirror 16, but it is not necessary to perform the correction based on the reflectance. Furthermore, the image exposure method of the present invention is not limited to performing main scanning using an optical deflector, but also uses an exposure element array such as a light emitting element array such as an LED array or a non-light emitting element array such as a liquid crystal shutter array. It can also be applied to systems that perform main scanning by irradiating one row simultaneously or sequentially.

Although the image exposure method and apparatus according to the present invention have been described using the color image exposure apparatus shown in FIG. 1 as a representative example, the present invention is not limited thereto, and the image exposure method of the present invention can be implemented. The present invention can be modified as appropriate depending on the image recording apparatus that can be used or the image recording apparatus that can be used with the image exposure apparatus of the present invention. In addition, such an image recording device may be a color or monochrome copying device, or a variety of image processing devices having an image reading unit, such as a computer, a video camera, or an optical disk. It may be a color or monochrome printer that receives color or monochrome image information processed by a processing device and records a color or monochrome image.

The recording material used may be a photosensitive drum or a color or monochrome photosensitive material as described above. Therefore, the image recording apparatus to which the present invention can be applied may be either color or monochrome, but for example,
In addition to the image recording device disclosed in No. 1552, electrophotographic image recording devices, silver salt photographic image recording devices, thermal transfer image recording devices, inkjet image recording devices, laser printers, laser copying devices, video printers, Other examples include video copying devices and image recording devices using various photosensitive materials, such as light-sensitive pressure-sensitive photosensitive materials, photosensitive resin materials, and the like.

Although the image exposure method and device thereof according to the present invention are basically configured as described above, the present invention is not limited thereto, and various improvements and designs can be made without departing from the gist of the present invention. Of course, it is possible to change.

Effects of the Invention> As detailed above, according to the image exposure method of the present invention, main particles formed on the recording material due to the exposure optical system and recording material conveyance system with normal processing accuracy and assembly accuracy are When a rask positional shift occurs on a scanning line, the density unevenness caused by the rask positional shift can be corrected by adjusting the exposure amount so that if the raster spacing is close, the density of the rask will be low, and if the raster spacing is far apart, the density of the rask will be darkened. Since it is possible to cancel the image and make it invisible, it is possible to easily obtain a reproduced image with good image quality and no density unevenness at low cost.

Further, according to the image exposure apparatus of the present invention, it is possible to detect the amount of surface tilt of the optical deflector such as the polygon mirror or galvanometer mirror of the exposure optical system and/or the conveyance position deviation due to uneven conveyance speed of the recording material conveyance system. Accordingly, the main scanning line, that is, the scan position shift of the rask due to the surface tilt amount and/or the conveyance position shift is calculated, and the exposure amount is adjusted so that the density of the rask becomes thicker or lighter depending on the distance of the rask interval. Density unevenness caused by the scanning position shift can be easily canceled out without using an expensive high-precision optical system or a conveyance system, and a reproduced image with good quality without density unevenness can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a rask (on the main scanning line) defined by adjusting the oblique amount, including a control system of an embodiment of an image exposure apparatus that implements the image exposure method according to the present invention. FIGS. 3a and 3b are perspective views of an embodiment of means for detecting the mirror surface of a polygon mirror used in the image exposure apparatus of the present invention. FIG. 4 is an explanatory diagram showing a rask defined by a conventional image exposure apparatus. Explanation of symbols 10... Image exposure device, 12... Light source section, 14... Surface tilt correction optical system, 16... Polygon mirrors 16a, 16g... Mirror surface, ! 8... Sub-scanning transport means, 20... Control unit, 22Y, 22M, 22C... Light source, 24Y, 24M, 24C... Driver, 26Y...
Reflection mirrors 26M, 26C...Dichroic mirrors 27, 27a
, 27b=light beam, 28...collimator lens, 30...cylindrical lens, 32...reflection mirror 34...drive source, 35...encoder, 36...scanning lens, 38... - Cylindrical mirror 40... recording material, 42... main scanning line (rusk), 44a, 44b, 46a, 46b... o-ra, 48...
... Belt, 50... Drive source, 52... Rotary encoder, 54... Microprocessor (μP), 56, 58...
...ROM, 60, 62, 64...RAM, 66...Exposure amount adjustment means, 68a, 68b, 68c, 68d, 68e, 68f, 6
8g...Rusk, 70, 74...Mirror surface detection means used, 71...Detected part, 72...Pickup, 75...Rotating disc, 76...Sli-nt, 77
a... Light emitting element, 77b... Light receiving element

Claims (2)

[Claims] (1) Main scanning is performed by sequentially irradiating the recording material with a light beam in a one-dimensional direction, and sub-scanning is performed by transporting the recording material in a direction substantially perpendicular to the main scanning direction, and the recording material is When performing two-dimensional exposure, the exposure amount is adjusted according to the interval between adjacent main scanning lines so as to cancel out density unevenness caused by positional deviation of the main scanning lines defined on the recording material that occurs in the sub-scanning direction. An image exposure method characterized by making adjustments. (2) Main scanning is performed by sequentially irradiating the recording material with a light beam in a one-dimensional direction, and sub-scanning is performed by transporting the recording material in a direction substantially perpendicular to the main scanning direction, and the recording material is An exposure apparatus that performs two-dimensional exposure, comprising at least one light source that irradiates the light beam, a light deflector that deflects the light beam in a one-dimensional direction, and sub-scanning transport that transports the recording material in a sub-scanning direction. means for detecting the amount of surface inclination of the optical deflector and/or means for detecting displacement of the conveyance position of the recording material due to uneven conveyance speed of the sub-scanning conveyance means; The distance between the main scanning line and the immediately preceding main scanning line is determined based on the amount of surface tilt and/or the conveyance positional deviation of the recording material detected by the detection means so as to cancel out the density unevenness caused by the positional deviation of the main scanning line in the sub-scanning direction. An image exposure apparatus comprising: a control means for calculating the interval and adjusting the exposure amount from at least the density of the immediately preceding main scanning line.