JPH0376660A - Image recorder - Google Patents

Abstract

PURPOSE:To suppress unevenness in tint or color and irregularities in density by a method wherein a dot pitch in the direction of feed is determined to be 1/3n (mm/dot) or less independent of a dot pitch in the direction of main scan ning when the number of reflecting surface of a rotating polyhedron is (n). CONSTITUTION:In an image recorder 10, a dot pitch in the direction of feed is determined to be 1/3n (mm/dot) or less independent of a dot pitch in the direction, of main scanning, where (n) is the number of reflecting surfaces of a polygon mirror 16. Therefore, it is preferable that a beam spot on a recording material 40 is shaped to have a diameter in the main-scanning direction larger than a diameter in the feed direction. In this manner, unevenness in tint or color and irregularities in density caused by, e.g., an error of a reflectance of the polygon mirror attributed to a difference of a wave length of an optical beam are not visually conspicuous or recognized, even if occurred. An image with a good gray balance improved in color balance and density balance can be recorded all over the surface.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a color image recording device.

More specifically, the present invention relates to an image recording device that can obtain full-color images with accurate gray balance.

<Prior art> The Rusk scan method, which is a scanning method used in television picture tubes, etc., obtains images such as text, pictures, photographs, and videos as visible images on recording materials such as paper and film. Applied to image recording devices.

Image recording devices using such a rusk scan method generally use a semiconductor laser, gas laser, light emitting diode, etc. as a light source, make the light beam emitted from this light source carry image information, and use a rotating polygon mirror (polygon mirror) to carry image information. A light deflector such as a mirror) or a galvanometer mirror deflects this light beam one-dimensionally for main scanning, and also sub-scans a recording material such as a photosensitive material or photoreceptor in a direction substantially perpendicular to the main scanning direction. The image is recorded by being conveyed by a conveying means, subjected to sub-scanning, and exposed two-dimensionally.

By the way, an image recording device using such a raster scan method is capable of recording images with better gradation reproducibility and better image recording in which density unevenness due to pitch unevenness caused by surface tilt or sub-scanning conveyance unevenness is less noticeable. In order to do −
Various image recording apparatuses have been proposed that apply a method of exposing a scanning line multiple times.

For example, Japanese Patent Application Laid-Open No. 60-169272 discloses a laser recording device that can record one line of image information with multiple beam scans, thereby recording a high-resolution, even image. The publication discloses an image recording apparatus that can obtain images with good gradation reproducibility even when using an A/D converter with a small number of bits using a similar method.

In addition, Japanese Patent Application Laid-Open No. 62-35765 discloses that by applying raster scanning and forming one pixel through multiple scans, density unevenness due to pitch unevenness caused by the tilt of the main surface of the polygon is made less noticeable. An image recording device capable of recording images is disclosed.

Furthermore, JP-A-61-220560, JP-A No. 61-277
In each publication of No. 263 and No. 62-179274,
An image recording method that can record images with uniform density, good gradation and tone reproducibility, and high resolution by scanning and exposing one scanning line multiple times with a light beam modulated by the same image signal. and devices are disclosed respectively.

<Problems to be Solved by the Invention> By the way, in an image recording device capable of recording color images, especially full-color images, in order to record color images with good color reproducibility and no color unevenness, it is necessary to accurately adjust the gray balance. I need to take it.

However, in image recording devices that use raster scanning and apply color photosensitive materials such as silver halide photosensitive materials,
Accurately achieving this gray balance is difficult, resulting in a color image with noticeable color unevenness.

Such image recording devices usually use three light beams having wavelengths capable of producing each color of cyan (C), magenta (M), and yellow (Y) of a color recording material. After the optical axes of the light beams are aligned, they are deflected in the main scanning direction by a light deflector such as a polygon deflector, and the color recording material being conveyed in the sub-scanning direction is scanned and exposed two-dimensionally to form an image. Recording is in progress.

By the way, a plurality of light sources emitted from a plurality of light sources such as LDs,
For example, three light beams with different wavelengths have variations in spread angle and different chromatic aberrations in the optical elements used, so the beam spot diameters on the photosensitive material do not perfectly match. Therefore, even if the optical axes of each light beam completely overlap, the beam diameters are slightly different, so the three light beams do not overlap completely in the vicinity of the beam spot, causing an imbalance in gray balance. This results in the inability to obtain accurate gray.

That is, even when exposed to a light beam of the same intensity, the peripheral area of the beam spot does not develop a good gray color and becomes a dull color that deviates from gray. In other words, it is not possible to accurately represent gray, resulting in a tinted gray, resulting in an overall recorded image with poor color balance and color unevenness.

Further, the reflectance of each reflective surface of a commonly applied polygon mirror differs slightly depending on the wavelength of the light beam.

That is, each color is slightly different depending on the light beam used to generate it.

For example, if the reflectance of a light beam with a wavelength that produces cyan in a recording material on a certain reflective surface is higher or lower than that of a light beam that produces magenta or yellow, even if each light beam has the same intensity, However, the scanning line exposed by this reflective surface still cannot express accurate gray with well-balanced gray.

Therefore, the color image obtained in this manner becomes an image with poor color balance and color unevenness.

In the image recording method that records one line (one pixel) through multiple exposures as disclosed in each of the above-mentioned publications, density unevenness caused by raster pitch unevenness caused by tilting of the polygon mirror surface, etc., and gradation reproducibility (gradation (key expression), it is possible to improve the resolution. However, in image recording devices that use color recording materials, color unevenness occurs due to microscopic gray balance imbalance caused by errors in the reflectance of polygon mirrors due to differences in the wavelengths of light beams of each color, and furthermore, color unevenness occurs due to the light source of each color. No consideration is given to eliminating color unevenness caused by microscopic gray balance deviations due to differences in beam spot diameters of light beams of each wavelength due to variations in beam divergence angle or chromatic aberration of optical elements used. No consideration was given to obtaining a good color image, especially a continuous-tone full-color image, with no visible tint or color unevenness.

An object of the present invention is to solve the above-mentioned problems of the prior art.
In particular, it is an image recording device that can record full-color images, and is capable of recording good images without visually perceiving main chromatic deviations in gray balance and with inconspicuous tint, color unevenness, and density unevenness. The purpose is to provide a recording device.

Means for Solving the Problems> In order to achieve the above object, the present invention deflects a plurality of light beams having different wavelengths in a main scanning direction using a rotating polygon mirror, and deflects the light beams substantially perpendicular to the main scanning direction. An image recording apparatus that records a color image by two-dimensionally scanning and exposing a color recording material conveyed in a sub-scanning direction, wherein the number of reflective surfaces of the rotating polygon mirror is n, The present invention provides an image recording apparatus characterized in that the dot pitch in the sub-scanning direction is set to 1/3 n (mm/dat) or less regardless of the dot pitch of the dot.

Further, it is preferable that the beam spot diameter of the light beam is larger in the main scanning direction than in the sub-scanning direction.

Further, the plurality of light beams having different wavelengths are used for cyan (C) and magenta (M) of the color recording material, respectively.
) and yellow (Y) are preferably used.

<Operation of the Invention> The image recording device of the present invention is an image recording device that applies a raster scan method and records a color image, particularly a full color image, using a color recording material such as a silver halide photographic material, and comprises: In the above-mentioned predetermined configuration, that is, when the number of reflective surfaces of the polygon mirror is n, the dot pitch in the sub-scanning direction is set to 1/3 regardless of the dot pitch in the main-scanning direction.
n (mn+/dat) or less.

Therefore, the scanning line interval (raster pitch) is narrower than that of a normal image recording device, and it is possible to make gray balance deviations around the beam spot less noticeable due to differences in the spread angle of each light beam and chromatic aberration. , it is possible to record a good image with excellent color balance, and the overall recorded image color balance can be visually confirmed to be accurate.

In addition, by setting the dot pitch in the sub-scanning direction to 1/3 n (mm/dot) or less regardless of the dot pitch in the main-scanning direction, for example, errors in the reflectance of the polygon mirror due to differences in the wavelengths of the light beams of each color can be avoided. due to color,
Even when color unevenness or density unevenness occurs, it is not visually noticeable or visible, and image recording with good gray balance over the entire surface and good color balance and density balance. It can be performed.

<Embodiments> Hereinafter, an image recording apparatus according to the present invention will be described in detail 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 recording apparatus of the present invention.

As shown in the figure, the image recording apparatus 10 of the present invention basically includes a light source section 12, a polygon mirror 16, a sub-scanning conveyance means 18, a control section 20 that controls image exposure, and a process (not shown). It consists of the following parts.

Since the image recording apparatus 10 of the present invention records a color image on the color recording material 40, the light source section 12 has three colors, for example, a light source 22Y1 for yellow (Y) and a light source for magenta (M
) light source 22M1 cyan (C) light source 22C, its driving sources (drivers) 24Y, 24M, 24C, collimator lenses 28Y, 28M, 28C, and a light beam 23Y emitted from the Y peripheral light source 22Y in a predetermined direction. The reflecting mirror 26Y1 transmits at least the light beam 23Y,
A dichroic main beam 26M1 that reflects the light beam 23M from the light source 22M in the same direction.
A dichroic mirror 26C that transmits the light beams 3Y and 23M and reflects the light beam 23C from the C light source 22C in the same direction.
It consists of

Note that the light source used in the present invention may be any light source as long as it can raster scan the recording material, but a laser light source is preferable.

For example, typically Ar laser, He-Ne laser, CO
Various lasers such as gas lasers such as 2 lasers, solid-state lasers, and semiconductor lasers (LDs), as well as light-emitting diodes (L
Examples include light emitting elements such as ED).

Reflection mirror 26Y1 Dichroic mirror 26M, 26
The light beam 27, in which the light beams 23Y, 23M, and 23C are unified by C, is then incident on the light beam shaping element 30, and the beam spot shape is changed to a color recording material (hereinafter referred to as
Use as recording material. ) 40 to form a predetermined shape.

Here, the image recording apparatus 10 of the present invention can set the dot pitch in the sub-scanning direction to 1 regardless of the dot pitch in the main scanning direction.
/ 3 n (am/dat) or less (n - the number of reflective surfaces of the polygon mirror 16), the recording material 4
It is preferable that the beam spot shape on 0 is formed so that the diameter in the main scanning direction is larger than the diameter in the sub-scanning direction. Note that this beam spot shape will be described in detail later.

The light beam shaping element 30 is not particularly limited, and any method can be applied to a normal light beam shaping element such as a slit, a beam reducer, or a prism.

The light beam 27 that has been shaped into a predetermined shape by the light beam shaping element 30 is reflected in a predetermined direction by the mirror 32 and enters the polygon mirror 16 .

The polygon mirror 16 is an optical deflector for one-dimensionally deflecting and reflecting the light beam 27 in the main scanning direction indicated by the arrow a, and has a plurality of reflecting surfaces, eight reflecting surfaces 16a in the illustrated example. has.

Here, the image recording apparatus 10 of the present invention has a dot pitch in the sub-scanning direction of 1/3 n (mm/dat) or less. Therefore, in the example shown in FIG.
Since the polygon mirror 16 has eight reflective surfaces, n=8 in this case, and the dot pitch in the sub-scanning direction is 1/3n=1/24=41.7- or less.

The polygon mirror 16 is rotated at a constant speed by a drive source 34 such as a motor. The drive source 34 also includes an encoder 34 for controlling the rotation of the polygon mirror 16.
a is attached, and sends rotation information of the polygon mirror 16 (drive source 34) to the control circuit 58 of the control section 20.

The light beam 27 deflected in one dimension by the polygon coupler 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.
The optical system is configured so that the main scanning line 42 is transmitted through the recording material 40, reflected by the elongated main beam 38, and lowered to form one main scanning line 42 on the recording material 40 conveyed by the sub-scanning conveyance means t8. Ru. Here, the main scanning line 42 defines one raster. Therefore, as described above, in the illustrated apparatus, the dot pitch in the sub-scanning direction is 41.7- or less, so the raster pitch is 41.7-μ or less.

The sub-scanning conveying means 18 moves the recording material 40 in the main scanning direction, that is, in the sub-scanning direction (direction indicated by the arrow) substantially perpendicular to the main scanning line 42, so as to be able to record images at a predetermined dot pitch of 41.7 pi or less. Any type of material may be used as long as it can be conveyed in the sub-scanning direction, and the most suitable one may be used depending on the form of the recording material 40.

The sub-scanning conveyance means 18 shown in FIG. 1 is constituted by two pairs of rollers 44a and 44b and 46a and 46b, and conveys a sheet-shaped recording material 40 while nipping it. A synchronous belt 48 is suspended on one side of each of the lower rollers 44a and 46a of the two roller pairs, and is synchronously driven by a drive source 50 attached to the roller 44a to convey the recording material 40 at a constant speed.

As shown in FIG. 1, the drive source 50 is attached to the rollers 44a of the two pairs of rollers that constitute the sub-scanning conveyance means 18, but the drive source 50 is not limited to this example, and can be attached to either roller. Alternatively, the two pairs of rollers may be driven through a transmission means such as a belt, a chain, or a gear, without being directly connected to these rollers. Drive source 50
A rotary encoder 52 is attached to the rotary encoder 52 and sends information on the rotation speed of the roller 44a, that is, the conveyance speed of the recording material 40 to the control circuit 58.

The control unit 20 controls the light source unit 12, polygon mirror 16, sub-scanning conveyance unit 18, etc. of the image recording apparatus 10 described above, and basically receives image information from the host 54 and prints an image according to the image information. Control circuit 5 sending a signal to modulator 60
8 and the image signal from the control circuit 58 for each color (C/M-
Each drive source 24Y, 2 is modulated into an exposure amount electrical signal for each
It is composed of a modulator 60 that sends signals to 4M and 24C. The IIJ# circuit 58 also includes the aforementioned encoder 34a.
Information is transferred from the rotary encoder 52,
Control circuit 58 sends an image signal to modulator 60 in response.

Here, the image recording apparatus 10 of the present invention has a dot pitch in the sub-scanning direction of 1/3n (mm/dQt) or less, regardless of the dot pitch in the main-scanning direction, as described above. Therefore, in the illustrated apparatus, the dot pitch in the sub-scanning direction is 41.7 pi or less as described above, and for example, in the case of a 400 dpi apparatus,
As shown in the figure, the dot pitch in the sub-scanning direction is set to 800.
It may be set to 31.75 μ/dot, which is equivalent to the DPI device.

As mentioned above, in normal exposure, exposure corresponding to each color of C, M, and Y is performed using different light sources (in the illustrated image recording apparatus 10, light source 22Y, light source 22M).
and light source 22C), the beam spot shapes of the light beams on the recording material 40 do not match due to differences in the spread angles of the light beams of the respective light sources and chromatic aberration. Therefore, the gray balance becomes microscopically out of order in the periphery of the beam spot.

In addition, the reflectance of the reflecting surface of the polygon mirror 16 that is normally applied differs somewhat for each reflecting surface, and even on the same reflecting surface, the light beams 23C123M and 23Y
There is a difference in reflectance depending on the color, which increases the gray balance and density unevenness of recorded images.

Such a problem is not a big problem if the method of exposing gradation images using an electrophotographic photoreceptor as disclosed in JP-A No. 61-277263 is used. Image recording devices that can express continuous tone images using color recording materials such as salt photographic materials tend to produce images with noticeable color unevenness or tinted unevenness with poor color balance. , it is not possible to record a good image.

On the other hand, in the image recording apparatus 10 of the present invention, the dot pitch in the sub-scanning direction is set to 1/3 n (mm/dot) or less, regardless of the dot pitch in the main scanning direction, thereby making color unevenness less noticeable. This makes it possible to record images with a flat feel.

The present inventor has proposed an image recording apparatus using a raster scan method that uses a polygon mirror (rotating polygon mirror) for main scanning and conveys a recording material in a direction substantially perpendicular to the main scanning direction in a sub-scanning direction. As a result of conducting various studies to reduce uneven color and density on recorded images caused by uneven reflectance of the reflective surface of polygon mirrors due to differences in the wavelength of the light beam, we have obtained the following findings and published this book. This led to the invention.

As shown in FIG. 3, not all density fluctuations ΔD that exist on an image are visible to the human eye as density unevenness, and there is a limit value of density variation that is visually recognized as density unevenness. The limit value is also not uniform, and depends on the wavelength (spatial period) and spatial frequency of density fluctuations in human vision.

That is, human vision is extremely critical in a certain wavelength range, that is, a spatial frequency range, for example, a wavelength of 0.5 to
10mm pitch range, i.e. spatial frequency 2~0
, In the range of 11ine/+nm, density fluctuations of Δ00.01 or less are recognized as density unevenness, but at spatial frequencies higher than this range (lower than the resolution of the eye) or lower, human vision is sensitive to density unevenness. become insensitive. Therefore, by making the spatial frequency of the density fluctuation larger or smaller than the above range, density unevenness can be made visually less noticeable.

In the image recording apparatus 10 of the present invention, as described above, regardless of the dot pitch in the main scanning direction, by setting the dot pitch in the sub-scanning direction to 1/3 n (mm/dat) or less, for example, the reflection of the polygon mirror 16 is reduced. Number of sides is 8
In the case of a surface, by setting the dot pitch to 41.7μ or less, the period of density unevenness can be adjusted to a wavelength of 0, 33 (mm
/1ine) or less, that is, the spatial frequency is 3 (line
For example, if the dot pitch in the sub-scanning direction is set to 31.75 dots/dot, which is equivalent to an 800 dpi device, as described above, the period of density unevenness will be approximately 0.25 ( mm/1ine)
Therefore, even if the density variation (ΔD) is 0.04 or more, there may be a slight discrepancy in the beam spot due to the divergence angle of the light beam of each color light source, chromatic aberration, etc., or a polygon blur due to the difference in the wavelength of the light beam of each color. This reduces the visibility of color and color unevenness due to imbalance in gray balance caused by differences in reflectance between surfaces, and also makes density unevenness due to surface tilting and differences in reflectance between surfaces less noticeable, while maintaining good gray balance. It is possible to obtain an image that can be visually recognized as being good and free of color unevenness.

Also, regarding the difference in reflectance of the polygon mirror 16 &:, the dot pitch in the sub-scanning direction is 63, 5) m (40
0d p L ) Te exposure and 31.754 (
800 dpi), an error in reflectance of 3 to 7 times is usually allowed, although it varies depending on the wavelength of the light beam.

Here, in the image recording apparatus 10 of the present invention, the beam spot shape of the light beam on the recording material 4o is larger in diameter in the main scanning direction than in the sub scanning direction, as shown in FIG. It is preferable to mold the material so that it becomes large.

As described above, the image recording apparatus 10 of the present invention has a dot pitch in the sub-scanning direction of 1/3 n (mm/dat) or less, regardless of the dot pitch center in the main scanning direction.

Therefore, one scanning line (one raster) in a normal image recording device is recorded with multiple scanning lines (two scanning lines in the illustrated example), and it is necessary to record multiple lines of the same data in the sub-scanning direction. .

However, if the same data is recorded in several sub-lines in the sub-scanning direction, there is a problem in that the resolution in the sub-scanning direction decreases.

In a normal image recording device, in order to record a good image without density unevenness, a light beam having a long beam spot shape in the sub-scanning direction is used to record an image by overlapping the front and back in the sub-scanning direction on the recording material. I do.

However, since the image recording apparatus 10 of the present invention has the above-described predetermined configuration, when recording an image using such a vertically elongated light beam, another beam is generated at a place where the beam spots overlap. Since the spot is inserted, the beam spot shape becomes long in the sub-scanning direction and large overall.

Therefore, the dot pitch in the sub-scanning direction becomes narrower, resulting in a decrease in resolution.

Therefore, in the present invention, preferably, the beam spot shape on the recording material 40 is set so that the main scanning direction is longer than the sub-scanning direction as shown in FIG.
It is preferable to make the er function as high as possible.

The shape of the beam spot on the recording material 40 is determined by the dot pitch (raster pitch) in the sub-scanning direction and the scanning speed of the light beam on the recording material 40, but it is more preferable to It is preferable that the spot shape has a size ratio of approximately 1:1 in the main scanning direction and in the sub-scanning direction, as in the combined beam spot 70 shown in FIG.

By adopting such a shape, the MTF in the main scanning direction and the sub-scanning direction can be set to almost the same value, and there is no difference in resolution between the main scanning direction and the sub-scanning direction, and a uniform and good image quality can be obtained over the entire surface. It is possible to record images.

Such a beam spot shape has, for example, a dot pitch of 63.5 dots (400 dp) in the main scanning direction as shown in the figure.
i), the dot pitch in the sub-scanning direction is 31.75 μ5 (8
00dpi) and the scanning speed of the light beam in the main scanning direction is approximately 309 m/sec, the beam diameter in the sub-scanning direction of the light beam is approximately 80p1, and the beam diameter in the main scanning direction is approximately 100μ. By doing so, the composite beam spot 7
0, the ratio of the sizes in the main scanning direction and the sub-scanning direction can be approximately 1:1.

In addition, since the dot pitch (raster pitch) in the sub-scanning direction of the present invention is narrower than that of a normal image recording device, raster pitch unevenness can be made less noticeable, and the surface tilt of the polygon roller 16 and inter-plane reflectance can be reduced. difference, recording material 4o
Tolerance limits for uneven conveyance speed, etc., are also high.

The image recording apparatus according to the present invention has been described above using the color image recording apparatus 10 shown in FIG. Any treatment of the recording material after exposure may be used as long as it is possible.

Further, the image recording device of the present invention may be a color copying device having an image reading section, or may be a color copying device having an image reading section.
Various image processing devices, such as computers, video,
It may be a color printer that records a color image by receiving color image information processed by a suitable image processing device even if it is an image from an optical disk.

Furthermore, there are no particular limitations on the color recording material to be used; for example, there are
Starting with the image recording device disclosed in Specification No. 52,
Silver salt photographic image recording devices, thermal transfer image recording devices, inkjet image recording devices, laser printers, laser copying devices, video printers, video copying devices, and various other photosensitive materials such as light-sensitive pressure-sensitive photosensitive materials, photosensitive materials Examples include image recording devices that use resin materials and the like.

Although the image recording device according to the present invention is basically configured as described above, the present invention is not limited to this.
Of course, various improvements and changes in design are possible without departing from the gist of the present invention.

<Effects of the Invention> The image recording apparatus of the present invention has the above-mentioned predetermined configuration.

Therefore, the scanning line interval (raster pitch) is 173n (n is the number of reflective surfaces of the rotating polygon mirror) compared to a normal image recording device.
This makes it possible to make the deviation of the main black gray balance around the beam spot less noticeable due to differences in the spread angle of the light beam of each color light source and chromatic aberration, and the gray balance is accurate throughout the recorded image. It is possible to record an image that can be visually recognized as having good color balance and no tint.

In addition, since the dot pitch in the sub-scanning direction should be 1/3n (mm/dot) or less regardless of the dot pitch in the main-scanning direction, for example, errors in the reflectance of the polygon mirror due to differences in the wavelengths of the light beams of each color, etc. Even if unevenness in color, color, or density occurs due to It can be performed.

Therefore, the image recording apparatus of the present invention is particularly suitable for obtaining high-quality full-color images with excellent color balance even in a microscopic sense.

Furthermore, as mentioned above, since the main scanning line spacing is narrow, even if the main scanning line spacing is disturbed or distorted due to uneven sub-scanning conveyance speed of the color recording material or tilted surface of the polygon mirror, the density will be reduced. It is possible to record an image that can be visually recognized as good and with no noticeable unevenness.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory diagram including a control system of an embodiment of an image recording apparatus according to the present invention. FIG. 2 is a schematic diagram showing an example of a beam spot shape of a light beam on a color recording material in an image recording apparatus according to the present invention. FIG. 3 is a graph showing the relationship between density variation and wavelength (and spatial frequency) for visually recognizing density unevenness due to human visual characteristics. Description of symbols 10... Image exposure device, 12... Light source unit, 16... Polygon roller 16a... Reflective surface, 18... Sub-scanning conveyance means, 20... Control unit, 22Y, 22M, 22C... light source, 24Y, 24M, 24C... driver, 26Y...
Reflection mirror 26M, 26C...Dichroic mirror 27.27
a, 27b”-light beam, 28Y, 28M, 28C... collimator lens, 30
... Beam shaping element, 32... Reflection mirror 34... Drive source, 34a... Encoder, 36... Scanning lens, 38... Long mirror 40... Recording material, 42...・Main scanning line (raster), 44 a, 44 b, 46 a, 4
6 b...Roller, 48...Belt, 50...Drive source, 52...Rotary encoder, 54...Host, 58...Control circuit, 0...Modulator, O...・Synthetic beam bot

Claims (1)

[Claims] (1) A plurality of light beams having different wavelengths are deflected in the main scanning direction by a rotating polygon mirror, and a color recording material transported in a sub-scanning direction substantially perpendicular to the main scanning direction is two-dimensionally scanned and exposed. In an image recording apparatus that records a color image using a rotating polygon mirror, when the number of reflective surfaces of the rotating polygon mirror is n, the dot pitch in the sub-scanning direction is set to 1/3n() regardless of the dot pitch in the main scanning direction. 1. An image recording device characterized in that the image recording device has an image recording capacity of less than 1 mm/dot.