JPH05289011A - Image recorder - Google Patents

Abstract

PURPOSE:To reduce the change of reflectivity and to perform image recording without generating density unevenness in a prescribed exposure quantity extending over the entire plane by comprising the reflecting plane of a light beam reflection member of silver thin film. CONSTITUTION:This recorder is an image recorder by raster scan which deflects a light beam 16 in a main scanning direction by a polygon mirror 22, etc., and performs the image recording on a photosensitive material A travelling in a subscanning direction orthogonal to the main scanning direction, and it is comprised of the polygon mirror 22, a lengthy mirror 20 which reflects the light beam in a prescribed direction and a cylindrical mirror 26 which comprises a plane inclination correction optical system, etc., and the silver thin film is used on the reflecting plane of a light mirror reflection member. The silver thin film generates small change in the reflectivity due to the incident angle, etc., of the light beam, and the deviation of exposure quantity on a scanning line can be reduced. Therefore, it is possible to prevent the density unevenness of an image by the deviation of the exposure quantity due to the difference of the incident angle of the light beam on an optical member from occurring, which enables the image recording with high picture quality to be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for recording an image by raster scanning, which has a simple structure and is capable of changing the reflectance and the transmittance of an optical member due to the difference in the incident angle of a light beam. The present invention relates to an image recording apparatus capable of recording a high-quality image that is small and has no noticeable density unevenness with a small exposure amount deviation on a scanning line.

[0002]

2. Description of the Related Art An image recording apparatus by so-called raster scanning, which records an image on a photosensitive material moving in the sub-scanning direction by two-dimensionally scanning and exposing the photosensitive material by a light beam deflected in the main scanning direction, is known. It is used for color or monochrome printers, copying machines, printing and plate making machines, etc.

In an image recording apparatus using a raster scan, for example, a light beam emitted from a light source such as a semiconductor laser (LD) is shaped into parallel light by a collimator lens, and then a cylindrical lens forming a plane tilt correction optical system. After passing through, it is incident on an optical deflector such as a polygon mirror or a galvanometer mirror. The light beam incident on the optical deflector is deflected in the main scanning direction and reflected, and is adjusted so as to pass through the fθ lens (scanning lens) and form an image in a predetermined shape at a predetermined position, which is troublesome with the cylindrical lens. The light is reflected by a cylindrical mirror forming a correction optical system, enters the photosensitive material at a predetermined scanning position, and defines a scanning line.

Since the photosensitive material is conveyed in the sub-scanning direction substantially orthogonal to the main scanning direction at the scanning position by means such as a pair of conveying rollers, the light beam consequently two-dimensionally conveys the photosensitive material. The image can be recorded by scanning.

In such an image recording apparatus, one of the causes of deteriorating the image quality of a recorded image is an excessive exposure amount on a scanning line due to a change in reflectance or transmittance of an optical member depending on an incident angle of a light beam. Insufficient (exposure deviation)
There is so-called shading, such as density unevenness due to the above, and density unevenness due to the exposure amount deviation due to the scanning speed difference of the light beam on the scanning line.

As described above, in the raster scanning image recording apparatus, the light beam is deflected in the main scanning direction by the optical deflector and is incident on the photosensitive material through the optical members such as the fθ lens and the falling mirror. Here, such an optical member needs to have an incident or reflection area that sufficiently deflects the light beam or sufficiently covers the deflected light beam, and the incident angle of the light beam varies depending on its incident position. ..

However, in optical members such as mirrors and lenses, it is extremely difficult in designing the optical members to exhibit predetermined optical characteristics over the entire light beam incident position and the entire incident angle. It is designed so that it can exhibit optimum optical characteristics in the area (light beam of normal incidence). Therefore, the reflectance and the transmittance of the light beam vary depending on the incident angle and the incident position of the light beam on the optical member, and in general, the light beam incident on the peripheral portion of the optical member and reflected or transmitted is The amount of light is reduced as compared with the light beam incident on the central portion. Therefore, the light amount of the light beam incident on the photosensitive material becomes insufficient at the end portion, resulting in an exposure amount deviation, and uneven image density occurs, so that a high quality image cannot be recorded.

On the other hand, in the raster scanning image recording apparatus, the scanning speed of the light beam deflected by the optical deflector on the photosensitive material is not constant due to the distortion aberration of the scanning lens, and both end portions from the central portion in the main scanning direction. The scanning speed becomes slower as it goes to. Therefore, even if the amount of light of the light beam is constant, the exposure amount becomes larger in both end portions than in the central portion in the main scanning direction, and density unevenness also occurs due to the exposure amount deviation.

That is, the exposure amount deviation due to the difference in reflectance or transmittance depending on the incident angle of the light beam to the optical member is insufficient in the peripheral portion, while the exposure amount deviation due to the velocity deviation causes the peripheral portion to be insufficient. It has a characteristic of canceling each other out that the exposure amount increases.

[0010]

By the way, in a normal image recording apparatus, a mirror having a plurality of dielectric layers formed on a reflecting surface of aluminum vapor deposition is applied to an optical deflector, a reflecting mirror, or the like. The reflectance of the reflecting surface formed by this aluminum vapor deposition greatly varies depending on the incident angle of the light beam, etc., and the exposure amount deviation due to this greatly exceeds the exposure amount deviation due to the velocity deviation. The exposure amount deviation due to the difference in the reflectance due to the difference in the difference becomes dominant.

Further, in the lens such as the fθ lens, the transmittance of the S-polarized light beam tends to largely decrease as the incident angle increases, and the exposure amount in the peripheral portion of the image decreases more. On the other hand, the P-polarized light beam does not decrease in transmittance depending on the incident angle of the light beam, and in this respect, it is preferable to use the P-polarized light beam for the image recording apparatus.

However, in a mirror having an aluminum reflecting surface, the P-polarized light beam has a greater change in reflectance depending on the incident angle than the S-polarized light beam.
There is a Brewster angle (polarization angle) at which the reflectance becomes 0 depending on the incident angle. Therefore, although it is advantageous in terms of the transmittance of the lens, a P-polarized light beam cannot be used in an image recording apparatus using raster scanning, and a normal image recording apparatus uses an S beam as a recording light beam. A polarized light beam is used, and in combination with the exposure amount deviation due to the above-mentioned mirror, the exposure amount deviation on the scanning line is made larger.

The density unevenness due to such an exposure amount deviation is
Although image recording with low gradation such as binary image such as electrophotographic image does not cause a large deterioration of image quality, it does not occur in gradation image such as image recording to which silver salt photographic light-sensitive material is applied. However, the image quality is greatly deteriorated. Therefore, in order to reduce the unevenness of the exposure amount, it is necessary to perform a correction for electrically processing the light amount of the light beam, that is, a shading correction.

On the other hand, in Japanese Patent Laid-Open No. 60-195502, the use of a copper reflecting surface such as copper vapor deposition as the reflecting surface of the optical deflector and the reflecting mirror causes a change in reflectance depending on the incident angle and the like. There is disclosed an image recording apparatus in which the excess and deficiency of the exposure amount to be reduced is reduced and the unevenness of the image density is reduced.

However, as is well known, the copper thin film is colored and absorbs a light beam having a short wavelength of about 700 nm or less. Therefore, as in electrophotographic image recording, there is no problem as long as it is an image recording that records color and monochrome images with only one light beam having a wavelength of 700 nm or more which has no absorption on the copper reflecting surface. When it is necessary to use a light beam that is absorbed, for example, in a silver salt photographic light-sensitive material, 670 nm corresponding to magenta color development, 750 nm corresponding to yellow color development, and 8 color corresponding to cyan color development.
When color image recording is performed using three light beams of 10 nm, a copper reflecting surface cannot be used.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to greatly reduce the change in reflectance due to the incident angle of a light beam on a light beam reflecting member such as an optical deflector or a cylindrical mirror. Further, preferably, by offsetting the exposure amount deviation in the main scanning direction due to the speed deviation of the light beam scanning, an image recording apparatus capable of performing image recording without density unevenness with a predetermined exposure amount over the entire surface. To provide.

[0017]

In order to achieve the above object, the first aspect of the present invention is directed to a sub-beam which is substantially orthogonal to the main scanning direction, and which has a light beam deflected in the main scanning direction by a scanning optical system. An image recording apparatus for irradiating a photosensitive material moving in a scanning direction and scanning the photosensitive material two-dimensionally to record an image on the photosensitive material, which constitutes a part or part of the scanning optical system. Provided is an image recording device, characterized in that the reflecting surfaces of all the light beam reflecting members are made of a silver thin film.

According to a second aspect of the present invention, the light beam deflected in the main scanning direction by the scanning optical system is applied to the photosensitive material moving in the sub scanning direction substantially orthogonal to the main scanning direction, An image recording device for recording an image on the photosensitive material by two-dimensionally scanning the photosensitive material, wherein a light beam deflected in the main scanning direction by the scanning optical system defines on the photosensitive material. In order to cancel the exposure amount deviation due to the scanning speed difference of the light beam at each position on the scanning line, the reflecting surface of a part or all of the light beam reflecting member constituting the scanning optical system is made of a silver thin film. A characteristic image recording apparatus is provided.

In the image recording apparatus, the light beam reflecting member having the reflecting surface made of a silver thin film,
It is preferably an optical deflector and / or an elongated reflective mirror that reflects the deflected light beam.

Furthermore, an image recording apparatus according to a third aspect of the present invention is the same as the image recording apparatus according to the first and second aspects of the present invention, in which the reflecting surface is formed of a silver thin film. Provided is an image recording device in which a dielectric thin film is formed on a silver thin film.

[0021]

According to the image recording apparatus of the present invention, an optical deflector such as a polygon mirror deflects a light beam in the main scanning direction to record an image on a photosensitive material which moves in a sub scanning direction substantially orthogonal to the main scanning direction. An image recording device by raster scanning, which performs a light deflector, a long mirror that reflects a light beam in a predetermined direction, a cylindrical mirror that constitutes a face tilt correction optical system, and the like as a reflecting surface of a light beam reflecting member. The basic structure is to use a silver thin film such as a silver vapor deposition thin film.

In the conventional raster scan image recording apparatus, the light deflector and the reflection mirror have a reflection surface formed by aluminum vapor deposition. However, since the reflectance of this aluminum reflecting surface varies greatly depending on the incident angle and position of the light beam, even when the light source is modulated and controlled so that the exposure amount is constant over the entire scanning line, The amount of light actually radiated on the photosensitive material, that is, the amount of exposure is not uniform over all scanning lines, resulting in an exposure amount deviation, which causes image density unevenness. In addition, since the S-polarized light beam has a strong dependency of the lens transmittance on the light beam incident angle, the light amount of the light beam incident on the peripheral portion is drastically reduced, and the exposure amount deviation on the scanning line becomes larger. It is preferable to use a P-polarized light beam that has a small decrease in transmittance depending on the beam incident angle.
However, the P-polarized light beam cannot be used as a recording beam because the reflectance of the P-polarized light beam is highly dependent on the incident angle.

On the other hand, in the image recording apparatus of the present invention, as a light deflector and a light beam reflecting member arranged on the downstream side of the light deflector as required, a reflecting surface of a silver thin film (preferably, a light reflecting surface). One having at least one dielectric layer) on a silver thin film is used. The silver thin film has a small change in reflectance due to the incident angle of the light beam and the like, and can significantly reduce the deviation of the exposure amount on the scanning line as compared with the conventional aluminum reflecting surface.

Moreover, in the reflecting surface of the silver thin film, unlike the conventional aluminum anti-slanting surface, the change in reflectance depending on the incident angle of P-polarized light can be small. Therefore, a P-polarized light beam can be used as a light beam for image recording, the light beam transmittance does not decrease due to the difference in the incident angle to the fθ lens, and the exposure amount deviation on the scanning line due to this does not occur. be able to.

Further, since the reflecting surface of the silver thin film is achromatic, unlike the copper reflecting surface disclosed in JP-A-60-195502, it can reflect a light beam of almost any wavelength without absorbing it. Color image recording using a plurality of types of light beams, for example, a color image using three light beams of 670 nm corresponding to magenta coloring, 750 nm corresponding to yellow coloring, and 810 nm corresponding to cyan coloring on a silver halide photographic light-sensitive material. It can be applied without any problems even when recording.

Therefore, according to the image recording apparatus of the present invention,
It is possible to record high-quality images without unevenness in image density due to the exposure deviation on the scanning line. Furthermore, the exposure deviation due to the incident angle dependence of the reflectance of the light deflector or the reflection mirror can be determined by the light beam scanning speed. By setting the characteristics so that the exposure amount deviation in the main scanning direction due to the deviation cancels out and becomes 0, it is possible to record a high-quality image with more uniform image density. In particular, when recording a gradation image such as an image recording on a silver salt photographic light-sensitive material, preferably recording a color image, it is possible to reproduce the gradation well and perform high-quality image recording. it can.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The image recording apparatus of the present invention will be described in detail below with reference to the preferred embodiments shown in the accompanying drawings.

FIG. 1 conceptually shows a perspective view of an example of the image recording apparatus of the present invention.

As shown in the figure, the image recording apparatus 10 of the present invention has C (cyan), Y (yellow) and M, respectively.
A semiconductor laser 12 (12C, 12Y, which emits light having a wavelength and an optical output for coloring (magenta)
12M) and the collimator lens 14 (14C, 14M) along the traveling direction of the light beam 16 (16C, 16Y, 16M) emitted from the semiconductor laser (LD) 12.
Y, 14M) and the cylindrical lens 18 (18C,
18Y, 18M), a reflection mirror 20, a polygon mirror 22, an fθ lens 24, and a cylindrical mirror 2
3 LD light different-angle incidence optical system having 6 and 6, a sub-scanning transporting unit for transporting the photosensitive material A (not shown) in the sub-scanning, a control circuit 28, and a modulation circuit 32 (32) of each LD 12.
C, 32Y, 32M) and the drive circuit 34 of each LD 12
(34C, 34Y, 34M), and the polygon mirror 22 and the cylindrical mirror 26 have a reflection surface of a silver thin film (hereinafter referred to as a silver anti-slope surface).

In such an image recording apparatus 10, a light beam deflected in the main scanning direction indicated by the arrow a while conveying the photosensitive material A in the sub scanning direction indicated by the arrow b in the figure by the sub scanning conveying means. An image recording device by raster scanning, in which the photosensitive material A is two-dimensionally scanned by each light beam to perform image exposure by scanning with the light beam 16, and the three types of light beams 16 are used for the polygon mirror 22. Incident on the substantially same point of the reflection surface 22a at slightly different angles, deflected in the main scanning direction, imaged at different positions on the same main scanning line on the photosensitive material A, and spaced at time intervals. This is due to the different-angle incidence optical system (non-combining optical system) that sequentially scans the main scanning line.

In the image recording apparatus 10, the 3LD light different-angle incidence optical system emits a light beam 16 (16C, 16Y, 16M) as the light source for emitting light of a predetermined narrow band wavelength, and three LDs 12 (12C, 12Y). , 12M). For example, the LD12C for emitting the C dye on the photosensitive material A emits light having a wavelength of 750 nm, and the LD12Y for emitting the Y dye of the photosensitive material A emits light having a wavelength of 810 nm. As the LD 12M for developing the M dye of the material A, one that emits light having a wavelength of 670 nm is applied. These LD12 are
It is controlled by an electric control system described later.

The image recording apparatus 1 of the present invention will be described in detail later.
Since 0 uses a silver reflecting surface for the reflecting surface 22a of the polygon mirror 22, the light beam 16 is preferably a P-polarized light beam. There is no particular limitation on the method of making the light beam 16 into P-polarized light, and the polarization property of laser light is used to
A known method such as a method of making the light beam 16 P-polarized by adjusting the angle of the laser light source (LD 12) may be used.

As described above, the image recording apparatus 10 of the illustrated example
Since the different angle incidence optical system is applied, the LD12
Emits a light beam 16 emitted by itself to the polygon mirror 12 at a predetermined angle and forms an image on the same main scanning line on the photosensitive material A at different angles, and on the same scanning line SL at time intervals. Are arranged so as to be sequentially scanned.

Light beam 16 emitted from each LD 12
Then enter the collimator lenses 14 (14C, 14Y, 14M) arranged corresponding to the respective light beams. The collimator lens 14 shapes each of the light beams 16 emitted from the LD 12 into parallel light. Next, the cylindrical lens 18 to be arranged
(18C, 18Y, 18M), the fθ lens 24 and the cylindrical mirror 26 form a plane tilt correction optical system, and corrects the plane tilt of the polygon mirror 22.

The light beam 16 that has passed through the cylindrical lens 18 is reflected in a predetermined direction by the reflection mirror 20 and is incident on the substantially same point of the reflection surface 22a of the polygon mirror 22 at slightly different angles, and then reflected. It is deflected in the main scanning direction (direction of arrow a in the figure).

Here, in the image recording apparatus 10 of the present invention, the reflecting surface 22a of the polygon mirror 22 and the reflecting surface of the cylindrical mirror 26 described later are formed of a silver thin film. This point will be described in detail later. The optical deflector applied to the image recording apparatus 10 of the present invention is not limited to the polygon mirror 26 of the illustrated example, and any known optical deflector such as a galvanometer mirror and a resonant scanner can be applied. .. Even in this case, the reflecting surface of the light beam 16 is of course formed by the silver thin film.

The fθ lens 24 is used to correctly form each light beam 16 at any position of the scanning line SL. The wavelength of the fθ lens 24 is 67
The chromatic aberrations are corrected so that the light of 0, 750, and 810 nm has an allowable range.

The cylindrical mirror 26 constitutes a plane tilt correction optical system together with the cylindrical lens 18 and the fθ lens 24, and lowers each light beam 16
The light is incident on the photosensitive material A toward a main scanning line SL that is substantially orthogonal to the sub-scanning direction on the photosensitive material A that is sub-scanned and conveyed. The reflecting surface of this cylindrical mirror 26 is formed of a silver thin film, like the polygon mirror described above.

As described above, in the conventional image recording apparatus, the reflection surface of the polygon mirror or the cylindrical mirror is formed by aluminum vapor deposition or the like. However, the reflection surface of the aluminum reflection surface depends on the incident angle and position of the light beam. Is significantly different. Therefore, the light amount of the light beam is reduced in accordance with the incident angle to the reflecting member, the light beam having a predetermined light amount is not incident over the entire scanning line SL, and an exposure amount deviation occurs, which causes image density unevenness. Will occur. In addition, the light beam 16 has a reduced transmittance due to the angle of incidence on the lens such as the fθ lens 24.
It is preferable to use a P-polarized light beam as
The polarized light beam has a strong dependence of the reflectance on the incident angle on the aluminum reflecting surface, and is difficult to apply to an image recording apparatus.

On the other hand, in the image recording apparatus 10 of the present invention, the reflecting surface 22a of the polygon mirror 22 and the reflecting surface of the light beam reflecting member such as the cylindrical lens 26 arranged downstream of the polygon mirror 22 are silver. It is formed by a thin film.

The silver reflecting surface formed by the silver thin film has a significantly smaller change in reflectance depending on the incident angle of the light beam than the conventional aluminum reflecting surface, and can greatly reduce the exposure dose deviation on the scanning line SL. Moreover, on the silver reflective surface,
Since the change in reflectance depending on the incident angle is small, the light beam 16
As a result, a P-polarized light beam having a small decrease in transmittance due to the angle of incidence on the fθ lens 24 can be used, and the exposure dose deviation on the scanning line by the fθ lens 24 can also be reduced.

Further, since the silver reflecting surface is achromatic, it does not absorb the light beam 16 having a short wavelength of 700 nm or less as in the conventional copper reflecting surface, and absorbs the light beams having almost all wavelengths. Since the light beam can be reflected without being reflected, a plurality of types of light beams 16 such as a light beam 16C having a wavelength of 750 nm, a light beam 16Y having a wavelength of 810 nm, and a light beam 16M having a wavelength of 670 nm are used as in the image recording apparatus 10 of the illustrated example. Even in a color image recording apparatus, there is no inconvenience such that a specific light beam is absorbed and an exposure amount is insufficient.

Therefore, the reflecting surface 22 of the polygon mirror 22
According to the image recording apparatus of the present invention in which a and the like are silver reflecting surfaces,
Image recording can be performed with an appropriate exposure amount with a small exposure amount deviation over the entire scanning line SL, and high-quality image recording without density unevenness can be realized. In particular, when recording a gradation image using a silver salt photographic light-sensitive material or the like, it is possible to record a high quality image in which gradation is well expressed.

By the way, as described above, in the image recording apparatus 10 based on the raster scan, the scanning speed of the light beam 16 deflected by the polygon mirror 22 on the scanning line SL is not constant, and goes from the central portion toward both end portions. Therefore, since the scanning speed becomes slower, the exposure amount becomes larger in both end portions than in the central portion in the main scanning direction. In the conventional image recording apparatus using the aluminum reflecting surface, the exposure amount deviation due to the reflectance change due to the incident angle of the light beam is significantly larger than the exposure amount deviation due to the scanning speed difference, and the exposure amount on the scanning line SL is large. The deviation becomes dominant here.

However, in the image recording apparatus 10 of the present invention using the silver reflecting surface, as described above, the exposure amount deviation (change in reflectance) due to the incident angle of the light beam on the optical member is small, and the scanning speed difference (speed). (Deviation), which is a level capable of canceling out the exposure amount deviation. Therefore, the exposure amount deviation (reflectance characteristic) in the incident angle of the light beam 16 of the polygon mirror 22 and the cylindrical mirror 26, the light beam 1
The scanning line SL is adjusted by adjusting the speed deviation of 6 scans or both of them to have characteristics that cancel each other out.
It becomes possible to perform extremely high quality image recording without the above exposure amount deviation. Particularly, gradation image recording such as image recording on a silver salt photographic light-sensitive material, preferably color image recording was performed. In this case, it is possible to reproduce the gradation well and perform high-quality image recording.

The adjusting method is not particularly limited and may be a known method. For example, the polygon mirror 22.
As a method of adjusting the reflectance characteristic, the dielectric layer provided on the silver thin film is used to adjust the reflectance characteristic by giving an increasing reflection effect and a reducing reflection effect to a predetermined angle and / or wavelength. Examples of such methods include:

The reflecting surface 22a of the polygon mirror 22
The silver reflection surface formed on the cylindrical mirror 26 is not particularly limited, but it is generally formed by vacuum vapor deposition or sputtering.

On such a silver reflecting surface, if necessary,
It is preferable to form various dielectric layers as the upper layer. The dielectric layer formed is not particularly limited, and SiO ₂ , Ti
Any known material such as O ₂ , ZrO ₂ , ZnS, etc. alone or in combination can be applied.

The light beam 16 reflected downward by the cylindrical mirror 26 scans the photosensitive material A along the scanning line SL, and scans and exposes the photosensitive material A.

Since the photosensitive material A is conveyed in the sub-scanning direction by the sub-scanning conveying means (not shown), the light beam 16 deflected in the main scanning direction consequently scans the photosensitive material A two-dimensionally. Image exposure.

The light-sensitive material applied to the image recording apparatus of the present invention is not particularly limited, and any known light-sensitive material such as silver salt photographic light-sensitive material, heat-development silver salt photographic light-sensitive material and electrophotographic light-sensitive material can be used. It is possible.

Here, since the image recording apparatus of the present invention can record an image with a predetermined exposure amount without deviation of the exposure amount on the scanning line SL, particularly, a silver salt photographic light-sensitive material,
It is preferably applied to a light-sensitive material for recording a gradation image such as a heat-developable silver salt photographic light-sensitive material. Among these light-sensitive materials for recording gradation images, particularly in a light-sensitive material having a γ characteristic value of about 2 to 5, more preferably, a γ characteristic value of about 3 to 4, a high image quality that expresses good gradation can be obtained. Images can be recorded. When focusing on the low-density portion, the desirable γ characteristic value is, for example, at D = 0.6, the γ characteristic value is 1.5 to 5,
It is preferably 2 to 4.

The control of the image exposure by the light beam 16, that is, the emission of the light beam by the LD 12 is controlled by the control circuit 28, the modulation circuit 32, and the drive circuit 34.

The control circuit 28 receives image information from an image signal source such as an image processing device, an image reading device, a computer, a video device, and an optical disk device, that is, an R (red) signal and a G signal.
The information of the (green) signal and the B (blue) signal is received, and various exposure amount corrections and signal processes are performed according to the image information signal to calculate the exposure amount of each pixel for one line for each color. Then, the exposure amount of each pixel for one line is determined for each LD 12.

Modulation circuit 32 (32C, 32M, 32Y)
Is a predetermined repetition cycle set in advance according to the exposure amount of each pixel of one line determined by the control circuit 28,
For example, the LD1
The light emission of No. 2 is pulse width modulated. In the pulse width modulation in this image exposure method, the light output of the LD 12 which is a light source is set to a constant value, and the time during which the LD 12 continuously emits light within one pixel period for each pixel, that is, one (1 pixel) continuous exposure The time is output to each drive circuit 34.

Drive circuit 34 (34C, 34M, 34Y)
Is a drive circuit for driving the LD 12, and in the case of pulse width modulation, is the time set for each pixel,
The drive current for the light output preset for each LD is L
Pour into D12. As a result, the LD 12 emits light at a light output set in advance for each LD for a time determined according to i pixels for each LD. This is performed over one line, and the LD 12 performs exposure for one line.

The drive circuit 34 is connected to the image signal source 28. The image signal source 28 controls the input timing of the image information signal for one line to the drive circuit 34, the light emission timing (pixel clock timing) of each LD 12, and the like.
Alternatively, it receives various signals and performs various controls necessary for the image recording apparatus.

Although the image recording apparatus of the present invention has been described in detail above, the present invention is not limited to the above-mentioned embodiment, and for example, between the optical deflector and the cylindrical mirror, or between the cylindrical mirror and the photosensitive material. A long mirror that raises or lowers the light beam optical path in a predetermined direction is arranged between them and has a silver reflecting surface, a configuration using a cylindrical lens instead of the cylindrical mirror, and the like of the present invention. Within the scope of the gist,
Of course, various improvements and changes may be made.

[0059]

As described in detail above, according to the image recording apparatus of the present invention, it is possible to cause a difference in the angle of incidence of the light beam on the optical member without the need for shading correction by electrical processing. By doing so, it is possible to record a high-quality image without image density unevenness due to the exposure amount deviation on the scanning line. In particular, when recording a gradation image such as an image recording on a silver salt photographic light-sensitive material, preferably recording a color image, it is possible to reproduce the gradation well and perform high-quality image recording. it can.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of an image recording apparatus of the present invention.

[Explanation of symbols]

10 image recording device 12 (12C, 12Y, 12M) semiconductor laser (L
D) 14 (14C, 14Y, 14M) Collimator lens 16 (16C, 16Y, 16M) Light beam 18 (18C, 18Y, 18M) Cylindrical lens 20 Mirror 22 Polygon mirror 24 fθ lens 26 Cylindrical mirror 28 Control circuit 32 (32C, 32C, 32Y, 32M) Modulation circuit 34 (34C, 34Y, 34M) Drive circuit

Claims (4)

[Claims] 1. A light beam deflected in a main scanning direction by a scanning optical system is applied to a photosensitive material moving in a sub-scanning direction substantially orthogonal to the main scanning direction, and the photosensitive material is two-dimensionally scanned. An image recording device for recording an image on the photosensitive material, characterized in that the reflecting surfaces of a part or all of the light beam reflecting members constituting the scanning optical system are made of a silver thin film. Recording device. 2. A light beam deflected in a main scanning direction by a scanning optical system is applied to a photosensitive material moving in a sub-scanning direction substantially orthogonal to the main scanning direction, and the photosensitive material is two-dimensionally scanned. An image recording device for recording an image on the photosensitive material, wherein the light beam deflected in the main scanning direction by the scanning optical system is a light beam at each position on a scanning line defining the photosensitive material. 2. An image recording apparatus characterized in that the reflecting surfaces of some or all of the light beam reflecting members constituting the scanning optical system are made of a silver thin film so as to cancel the exposure amount deviation due to the scanning speed difference. 3. The image recording apparatus according to claim 1, wherein the light beam reflecting member having the reflecting surface made of a silver thin film is an optical deflector and / or a long reflecting mirror for reflecting the deflected light beam. .. 4. The image recording device according to claim 1, wherein a dielectric thin film is formed on an upper layer of the silver thin film of the light beam reflecting member having the reflecting surface made of a silver thin film. Image recording device.