JP2001255595A - Laser beam exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam exposure device simple in optical adjustment with suppressed loss of the light quantity without the density fluctuation owing to the interference unevenness. SOLUTION: In the laser beam exposure device, a photosensitive material F having at least one supporting body layer or one photosensitive layer which is transmissible or semitransmissible to a wavelength to be used is irradiated with a laser beam form laser beam sources 125 and 127 and exposed. A beam irradiation area consisting of a one scanning line or a plurality of continuous scanning lines is set as one linear area, or a beam irradiation area consisting of one pixel or a plurality of continuous pixels is set as one pixel area, and the photosensitive material F is irradiated with a laser beam having light quantity-wavelength characteristics of the irradiation beam different between the adjacent linear areas or between adjacent pixel areas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam exposure apparatus for irradiating a photosensitive material such as a silver halide photosensitive material with a laser beam to form an image on the photosensitive material, and more particularly, to an image by laser interference in the photosensitive material. The present invention relates to a laser beam exposure apparatus capable of suppressing unevenness.

[0002]

2. Description of the Related Art Hitherto, a silver halide photographic material has been exposed to laser light in order to record an image based on image data. In recent years, a silver halide photothermographic material which does not require a liquid treatment and can visualize an image by thermal development has appeared. However, when this is exposed with a laser beam, interference fringes may occur and image unevenness may occur. This phenomenon will be described with reference to FIG. 12, which is a conceptual diagram showing the relationship between the cross section of the film and the laser beam.

As shown in FIG. 12A, when a laser beam is incident on a film F composed of a photosensitive layer of a silver halide photothermographic material and a support such as PET from a front surface F1, a laser beam is applied to a back surface F2. The portion reflects and returns to the surface F1, so that between the light B1 directly irradiating the recording layer and the light B2 reflected on the F2 surface of the light transmitted through the photosensitive layer and further reflected on the F1 surface. Interference occurs. For this reason, the amount of light applied to the photosensitive layer varies depending on the thickness of the film, and as a result, the exposure amount of the photosensitive material of the silver halide heat-developable photosensitive material to the photosensitive layer fluctuates, causing density unevenness.

The light B1 directly applied to the photosensitive layer and F2
B2 irradiating the recording layer after being reflected by the surface F1
When the optical path difference δ is an integral multiple of the laser wavelength, the amount of light irradiated to the photosensitive layer becomes maximum, and when the optical path difference δ deviates from the integral multiple by a half wavelength, it becomes minimum. The reflectance R at the interface between media having different refractive indices is represented by n which is the refractive index of each medium sandwiching this interface.
A and nB can be represented by the following equation (1).

R = ((nB−nA) / (nB + nA)) ² (1)

Here, for example, the refractive index of each layer of the photosensitive material is the same and uniform, and nB = 1 (air) and nA = 1.5.
(Photosensitive material), the reflectance R at the interface between the air and the photosensitive material is 4%. Further, the change in light amount (peak-to-peak) ΔA due to interference can be expressed by the following equation (2), and in the above case, it is as large as 16%.

ΔA = 4R (2)

Actually, as shown in FIG. 12B, a laser beam absorbing layer is provided on the back surface F2 side of the support.
Further, since the scattered light s is generated by the silver halide particles contained in the photosensitive layer, the change in the amount of light due to interference is smaller than the above value. However, if there is a slight difference in the refractive index between the absorption layer and the support, reflection occurs at the interface F2 between the absorption layer and the support, and the absorption layer does not contribute. Further, conventional photosensitive materials contain large silver halide grains and can be provided with a plurality of absorption layers, so that interference fringes are unlikely to occur. Silver halide grains are finer than the material, scattering in the photosensitive layer is much less than conventional films,
In the case of a heat development material having a high γ of 2 or more, the interference fringes become remarkable.

The above-mentioned fluctuations in light amount due to interference can be prevented by the following measures (1) to (3). (1) An antireflection film is provided on the back surface (F2) of the support to reduce the reflectance on the surface F2 between the support and the absorbing layer. (2) The thickness variation of the support is suppressed to a fraction of the wavelength of the laser beam (generally, 0.5 μm to 1.5 μm). (3) The difference in refractive index between the support and the absorption layer is reduced, and the reflectance at the interface F2 between the support and the absorption layer is reduced.

However, the countermeasure (1) leads to an increase in cost, which is not preferable. Regarding the measure (2), it is possible to suppress the dispersion of the medium having a thickness of several μm,
It is almost impossible to suppress the variation of the medium having a thickness of μm or more to sub μm or less. Further, with respect to the measure (3), even if the difference in refractive index is as small as 0.05 or less, interference fringes will be caused, and it is almost impossible to make the difference in refractive index between the two smaller than this level.

Further, Japanese Patent Application Laid-Open No. 11-48523 discloses that a recording material is irradiated with light from laser light sources having different wavelengths in a superimposed manner in order to prevent the occurrence of interference fringes. However, in this case, two or more laser light sources are necessarily required, and the laser beam itself is a beam in which interference is suppressed. Therefore, it is necessary that two laser beams overlap and coincide in the main scanning direction and the sub-scanning direction. Therefore, optical adjustment of the laser light source and the optical system becomes difficult, and the efficiency of the optical adjustment at the time of manufacturing and maintenance is reduced. Furthermore, a shift between two beams is likely to occur due to a change over time or an environmental change. If a shift occurs between the beams, interference unevenness is not sufficiently suppressed, and the beam diameter also changes, resulting in blurring, sharpness reduction, etc. Image quality is likely to deteriorate.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has been made in view of the above-mentioned problems. An object of the present invention is to provide an exposure apparatus.

[0013]

In order to achieve the above-mentioned object, a laser beam exposure apparatus according to the present invention has at least one support layer or photosensitive layer which is transparent or semi-transparent to the wavelength used. A laser beam exposure apparatus for irradiating a photosensitive material with a laser beam from a laser light source and exposing the same to one scanning line or a plurality of continuous scanning lines irradiated by the laser beam. A linear region is defined, and between the adjacent linear regions, the photosensitive material is irradiated with laser beams having different light quantity-wavelength characteristics.

According to this laser beam exposure apparatus, a beam for each scanning line interferes in a linear area, and there is interference unevenness in a micro space. Since the wavelength characteristics are different, the interference unevenness becomes invisible in macro space. Thereby, the quality of the formed image is improved. Further, since the light amount-wavelength characteristics of the irradiation beam are different, the light amount can be made the same even if the wavelength changes, so that the switching scanning line interval can be narrowed, and the macro space region where interference unevenness can be made invisible can be narrowed. For this reason, even if the macro space region is enlarged, the interference unevenness can be sufficiently invisible. The light quantity-wavelength characteristic can be changed by changing the light quantity-wavelength characteristic by controlling the temperature of the laser light source or by selecting laser diodes having different light quantity-wavelength characteristics.

Further, since it is not necessary to make the two laser beams coincide with each other, it is possible to at least correct the beam shift in the main scanning direction, and the optical adjustment and maintenance become easy. As a method of correcting the beam position shift in the main scanning direction, a synchronous sensor signal that determines the writing start timing of each scanning line is used, and the writing start timing of each scanning line is shifted by the beam position shift in the main scanning direction of each scanning line. Can be corrected. Furthermore, unlike the conventional case, two laser light sources are not necessarily required, and one laser light source may be used. In this case, since there is no problem of a shift between the two laser beams with respect to a change with time or an environmental change, it is stable. Interference unevenness is suppressed, and good image formation can be stably performed.

The switching of the wavelength at the time of laser irradiation may be such that two switching patterns are alternately changed for each predetermined scanning line, a plurality of patterns may be sequentially switched, or a repetition thereof.

Further, the light quantity-wavelength characteristics can be made different by the fact that the pattern of density unevenness is reversed between the linear region and the adjacent linear region. Further, in the range including the linear region and the adjacent linear region, the interference unevenness is made invisible.

Further, since the number of the laser light sources is one, the structure becomes optically simple, the optical adjustment at the time of manufacture and maintenance becomes easy, the cost becomes advantageous, and the wavelength of the plurality of laser light sources is increased. Sorting is not required.
In this case, it is preferable to irradiate the photosensitive material by switching the light quantity-wavelength characteristics between the adjacent linear regions by the one laser light source.

When there are a plurality of laser light sources,
Correction is possible even if the laser beam is shifted in the main scanning direction,
The laser beams in the main scanning direction do not necessarily have to match. For this reason, optical adjustment at the time of manufacture and maintenance is relatively easy, and it is advantageous in terms of cost. In this case, the plurality of laser light sources having different light quantity-wavelength characteristics are used.
It is preferable to irradiate the photosensitive material by switching between the adjacent linear regions.

Further, as the photosensitive material, a material which easily interferes can be used, and when the material and the structure of the photosensitive material are determined, the range of choices is widened and is preferable.

Further, the light amount-wavelength characteristic is changed over while modulating the temperature of the laser light source over a predetermined range to perform exposure of the photosensitive material. Although it occurs, it is modulated at a high spatial frequency, so that interference unevenness can be sufficiently invisible. In this case, it is preferable to irradiate the photosensitive material with the laser light source having the light amount-wavelength characteristic changed by changing the temperature of the laser light source, switching between the adjacent linear regions.

Further, by performing the modulation for each of the linear regions, the interference unevenness can be more effectively made invisible.

Further, the laser light source includes a laser element such as a laser chip, and temperature control can be performed quickly and accurately by directly connecting a temperature control member to the laser element. The modulation can be performed by injecting a light beam for temperature modulation of another wavelength into the laser light source and modulating the light amount of the light beam. Thereby, the temperature control speed can be increased. Further, the modulation can be a random temperature modulation. Thereby, interference unevenness can be reduced as a whole. Further, the modulation can be performed between binary temperatures at which the interference pattern is reversed.

Another laser beam exposure apparatus according to the present invention provides a laser beam exposure apparatus for a photosensitive material having at least one support layer or photosensitive layer which is transmissive or semi-transmissive to the wavelength to be used. A laser beam exposure apparatus for irradiating and irradiating light, wherein one pixel area irradiated by the laser beam or a beam irradiation area composed of a plurality of continuous pixels is defined as one pixel area, and irradiation is performed between adjacent pixel areas. The light quantity-wavelength characteristics of the beam are different.

According to this laser beam exposure apparatus, the laser beam interferes between the pixels in the pixel area and there is interference unevenness in the micro space. Since the characteristics are different, the interference unevenness becomes invisible in macro space. Thereby, the quality of the formed image is improved. In addition, since the beam irradiation area is configured in pixel units, the macro space area in which the interference unevenness can be made invisible can be narrowed, so that the interference unevenness can be made invisible even when viewed in a larger scale.

Further, the light quantity-wavelength characteristics can be made different by the fact that the density unevenness pattern is reversed between the pixel area and the adjacent pixel area. Further, the pixel area is an area where interference unevenness is made invisible.

The number of the laser light sources may be one or more. Further, the photosensitive material can be made of a material that easily interferes.

In this case, the amount of light by the one laser light source
It is preferable to irradiate the photosensitive material by switching wavelength characteristics between the adjacent pixel areas, and to switch the plurality of laser light sources having different light quantity-wavelength characteristics between the adjacent pixel areas. Preferably, the material is irradiated.

Further, the light amount-wavelength characteristic can be switched while modulating the temperature of the laser light source over a predetermined range or more to expose the photosensitive material. in this case,
It is preferable that the photosensitive material is irradiated with the laser light source whose light quantity-wavelength characteristic is changed by changing the temperature of the laser light source, by switching between the adjacent pixel areas. Further, the modulation can be performed for each pixel area. Further, the laser light source includes a laser element such as a laser chip, and a temperature control member can be directly coupled to the laser element.

Further, the light-sensitive material can be a silver halide light-sensitive material. In this case, the silver halide photosensitive material may be obtained by dry thermal development or wet development.

Preferably, the laser beam exposure apparatus records an image by amplitude modulation. When a plurality of laser light sources are used, it is preferable to select the laser beam so that the difference between the center peak wavelengths substantially matches the desired wavelength difference. For example, the laser diode can be selected from standard laser diodes of different types. As a result, it is not necessary to select a plurality of laser light sources, and it is possible to reduce the purchase cost.

When a temperature difference is given to the laser light source,
Preferably, a laser beam from the laser light source is monitored, its wavelength or wavelength difference is detected by a sensor, and when the wavelength deviates from a predetermined wavelength difference, this deviation is fed back to change the set temperature of the laser light source. At this time, for example, when two laser light sources are used, both laser light sources may be controlled as described above, or one of them may be controlled. This eliminates the need for selecting a laser light source, and since the wavelength difference can always be kept constant with time or environmental change, interference unevenness can be suppressed stably, and good image formation can be stably performed.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of preventing interference fringes with two laser beams having different wavelengths will be described with reference to FIGS. The support layer and the photosensitive layer of the film F are transmissive or semi-transmissive for the wavelength used. (1) When the laser has a single wavelength (the amount of light varies due to interference)

Consider a case where a laser beam is vertically incident on the film F as shown in FIG. The thickness D2 of the photosensitive layer of the film F which is a silver halide photothermographic material is 20 μm, the refractive index n2 is 1.5, the thickness D1 of the support 1 is 180 μm, the refractive index n1 is 1.5, and the When the wavelength is 0.800 μm, the optical path difference δ = 2 (D1 × n1 + D2 × n2) = 2
× (180 × 1.5 + 20 × 1.5) = 600 μm
600 / 0.8 = 750, which is an integral multiple of the wavelength. The laser beam shown in FIG. 1 has a phase as shown in FIG. 2A at the incident point 5 on the front surface F1 of the film F on the photosensitive layer 2 side, and the incident light is partially reflected by the back surface F2 of the film, and the reflected light is reflected. The light is reflected at the incident point 5 of the film F. At the incident point 5, the phase is as shown in FIG. 2B, and since both phases coincide with each other, the amount of light applied to the recording layer 2 becomes the maximum. On the other hand, when the thickness of the support is 180.13 μm, the optical path difference δ is 7 wavelengths.
50.5 times, reflected on the back surface F2, and further on the front surface F1
The phase of the laser beam reflected at the point of incidence 5 is as shown in FIG. 2C at the incident point 5 and is exactly opposite to the phase of FIG. 2A. The amount of light applied to the layer 2 is minimized. As described above, the amount of light applied to the recording layer 2 changes due to the variation in the thickness of the support 1 of the film F. (2) When the laser has two wavelengths

In the above example, if each were 0.8 μm,
If exposure is performed using two laser beams having a wavelength of 0.80053 μm, the above-described optical path difference of 600 μm becomes 750 times and 749.5 times the wavelengths of these two laser beams, respectively, and the photosensitive layer 2 is irradiated. The light amount is the sum of the two, that is, halfway between the maximum and the minimum. Here, for example, the optical path difference is 60
Even if it becomes 0.4 μm, this optical path difference of 600.4 μm is
For each of the two laser light wavelengths, 750.
5 times and 750 times, and the amount of light irradiated on the photosensitive layer is also halfway between the minimum and the maximum. That is, even if the thickness of the support 1 changes, the amount of light applied to the photosensitive layer does not change.
As described above, it can be understood that the influence of interference can be reduced by irradiating laser light having two different wavelengths.

Next, referring to FIGS. 8 and 9, in order to reduce the influence of interference as described above, the beam irradiation area surrounded by one or a plurality of scanning lines is set as one linear area, How to change the light quantity-wavelength characteristic of the irradiation beam between the linear regions to be performed will be described.

As shown in FIG. 8, the first laser light source is
When the second laser light source has the light amount-wavelength characteristic as shown by a broken line 91 and the second light source has the light amount-wavelength characteristic as shown by a dashed line 91, the wavelength λ1 and the second wavelength Output a laser beam of wavelength λ2.

Here, first, the wavelength λ1 from the first light source
When the main scanning is performed by using the laser beam, as shown in FIG.
Assuming that the first linear region is one scanning line in the main scanning direction, an interference pattern appears on this scanning line (repetition of ● in FIG. 9 represents the interference pattern). In the next scanning line which is a linear area, when the main scanning is performed with a laser beam having a wavelength λ2 from a second light source having a different light amount-wavelength characteristic, the first scanning line in the second linear area as shown in FIG. An interference pattern appears at a phase different from that of the linear region. Therefore, when considering the entire region including the first linear region and the second linear region, as described above, two laser beams having different wavelengths are irradiated, and thus the macroscopic region is irradiated. In this way, interference can be suppressed. Therefore,
In the example of the irradiation pattern in FIG. 9, by repeating the exposure in the third linear region in the same manner as in the exposure of the first linear region, the interference unevenness can be made invisible macroscopically in the entire film.

Further, since the light amount-wavelength characteristic of the irradiation beam is different, the light amount is the same even if the wavelength changes, so that the switching scanning line interval can be narrowed, and a macro space region in which interference unevenness can be made invisible can be obtained. Can be narrow. For this reason, even if the macro space region is enlarged, the interference unevenness can be sufficiently invisible.

As described with reference to FIGS. 1 and 2, interference unevenness (layers between the support and the photosensitive layer) due to multiple beam reflection inside the photosensitive material can be easily suppressed. Since there is a change in the light amount for each scanning line, there is a change in the wavelength for each scanning line. Therefore, there is a shortfall in switching the wavelength alone, but the light amount-wavelength characteristic of the laser beam irradiated between adjacent linear regions is not sufficient. Are different from each other, and as described above, the interference unevenness is made invisible in the macro space.

Although FIG. 8 illustrates the first laser light source and the second laser light source having different light quantity-wavelength characteristics, the present invention is not limited to this.
The light amount-wavelength characteristic may be changed by controlling the temperature of the laser light sources using two laser light sources.

Next, an irradiation pattern different from that in FIG. 8 will be described with reference to FIG. In the example of FIG. 14, two main scans are performed at the same wavelength λ1, two scan lines are used as a first linear region, and then two main scans are performed at another different wavelength λ2. The line is defined as a second linear region, and then the main scanning is performed twice at λ1, and the laser beam is exposed so that the two scanning lines are defined as a third linear region. Interference unevenness occurs microscopically in the scanning line of each linear area, but the first linear area and the second
Considering the entire region including the linear region described above, two laser beams having different wavelengths are irradiated as described above, so that macroscopic interference can be suppressed.

As described above, the exposure pattern according to the present invention can be modified in various ways. In addition to using a beam irradiation area composed of one scanning line or a plurality of continuous scanning lines as one linear area, A beam irradiation area composed of one pixel or a plurality of continuous pixels may be regarded as one pixel area, and the light amount-wavelength characteristics of the irradiation beam may be different between adjacent pixel areas.

Hereinafter, embodiments and examples which are examples of the present invention will be described. Therefore, the meaning of the terms of the invention and the invention itself should not be construed as being limited by the description of the embodiments and examples of the invention, and it is needless to say that the invention can be appropriately changed / improved.

FIG. 3 is a front view of an image recording apparatus including the laser beam exposure apparatus of the present embodiment, and FIG. 4 is a left side view of the image recording apparatus. The image recording apparatus 100 according to the present embodiment includes a feeding unit 110 that feeds a film F that is a sheet-like heat developing material one by one, an exposure unit 120 that exposes the fed film F, and an exposure unit 120 that exposes the film F. And a heat developing section 130 for developing the processed film F. Film F is a silver halide photothermographic material having a photosensitive layer containing silver halide particles and organic acid silver on a support, and γ of 2 or more. Hereinafter, an image recording apparatus according to the present embodiment will be described with reference to the drawings.

In FIGS. 3 and 4, the feeding section 110 is provided with trays T for accommodating a plurality of deposited films F in two upper and lower stages. Above the front end of each tray T, there is provided a suction unit 111 that moves up and down by sucking the front end of the film F. In addition, the suction linear region 11
In the vicinity of 1, there is provided a feed roller pair 112 for feeding the film F supplied by the suction unit 111 in the direction of the arrow (1) (horizontal direction). Also, the suction unit 11
1 transports the film F, which is also movable back and forth, to the feed roller pair 112. A plurality of transport roller pairs 141 for transporting the film F fed by the feed roller pair 112 in the vertical direction are provided. The transport roller pair 141 transports the film F in the direction (downward) indicated by the arrow (2) in FIG.

A transport direction converter 145 is provided below the image recording apparatus 100. This transport direction converter 1
Reference numeral 45 denotes a pair of transport rollers 14 as shown in FIGS.
1, the film F conveyed vertically downward as shown by the arrow (2) in FIG. 4 is conveyed in the horizontal direction as shown by the arrow (3), and then the conveyance direction is changed from the arrow (3) to the arrow (4). The film F is transported after being converted to a right angle, and then the transported film F whose transport direction is changed and transported is transported upward in the vertical direction shown by the arrow (5) in FIG.

Then, as shown in FIG. 3, the film F transported from the transport direction changing unit 145 is moved by the arrow (6) in FIG.
Plural transport roller pairs 14 transported vertically upward as indicated by
2 is provided, and the film F is transported from the left side of the image recording apparatus 100 upward in the vertical direction indicated by the arrow (6) in FIG.

The laser beam exposure apparatus 120 scans and exposes the photosensitive surface of the film F with a laser beam having a wavelength in the infrared range of 780 to 860 nm during the upward transport in the vertical direction. Latent image is formed.

A heat developing unit 130 is provided at the upper part of the image recording apparatus 100. In the vicinity of the drum 14 of the heat developing unit 130, a pair of conveying rollers 142 is used to move the heat developing unit 130 vertically upward as shown by an arrow (6) in FIG. A supply roller pair 143 for supplying the film F conveyed to the drum 14 to the drum 14 is provided.

The film F is supplied to the drum 14 at a random timing depending on the situation. In addition, instead of supply at random timing, supply may be performed at a certain timing.

The drum 14 of the heat developing unit 130 heats the film F while rotating in the direction indicated by the arrow (7) in FIG. 3 with the film F and the outer peripheral surface of the drum 14 in close contact with each other. And heat develop. That is, the film F
Is formed into a visible image. Then, the drum 1 of FIG.
The film F is separated from the drum 14 when the film F is rotated to the right with respect to the film 4. A plurality of transport roller pairs 144 are provided on the right side of the thermal developing unit 130, and while transporting the film F separated from the drum 14 obliquely downward to the right as shown by an arrow (8) in FIG. Cooling. Then, the transport roller pair 144 transports the cooled film F while the densitometer 1
18 measures the concentration of the film F. Thereafter, the plurality of transport roller pairs 144 are moved to the film F separated from the drum 14.
3 is transported in the horizontal direction as shown by an arrow (9) in FIG. 3, and is ejected from the upper part of the image recording apparatus 100.
To be discharged.

FIG. 5 is a conceptual diagram showing the configuration of the laser beam exposure apparatus 120. Laser beam exposure device 120
The laser light L, the intensity of which is modulated based on the digital image signal S, is deflected by the rotary polygon mirror 113 to perform main scanning on the film F, and the film F is moved substantially in the main scanning direction with respect to the laser light L. Sub-scanning is performed by relative movement in a perpendicular direction, and a latent image is formed on the film F using the laser beam L.

The image recording apparatus 100 includes a radiation CT apparatus,
The image signal S transmitted from the image signal generation device 121 such as a scanner is received via the image I / F 122 and the modulation unit 1
23. The modulation unit 123 converts the image signal S into an analog signal, and sends the analog-converted exposure image signal to the driver 124. The driver 124 outputs the laser light source units 125 and 127 according to the transmitted exposure image signal and the control signal.
Is controlled so as to emit a laser beam (hereinafter, also referred to as “laser light”) while switching every time the main scanning is completed.

The two laser light source sections 125 and 127 have, for example, different light quantity-wavelength characteristics as shown in FIG. 8 and are constituted by laser diodes which emit laser beams having different wavelengths (λ1, λ2). The wavelength (λ1) of the laser light emitted from the laser light source unit 125 is set to, for example, 800 nm, and the wavelength (λ2) of the laser light emitted from the laser light source unit 127 is, for example, 800.53n.
m.

As shown in FIG. 5, the laser light L1 emitted from the laser light source unit 125 travels straight through the half mirror 128b and enters the condenser lens 126. On the other hand, the laser light source 12
The laser light L2 emitted from 7 passes through the same optical path as the laser light L1 via the mirror 128a and the half mirror 128b, and is incident on the condenser lens 126.

The laser beam L1 or L2 emitted from the laser light source units 125 and 127 has its beam diameter converted by the condenser lens 126, and is transmitted by the cylindrical lens 115 in one direction.
(In the present embodiment, only in the vertical direction), and enters the mirror surface of the rotating polygon mirror 113 rotating in the rotation direction indicated by the arrow A in FIG. 5 as a line image perpendicular to the rotation axis of the rotating polygon mirror. It has become. The rotating polygon mirror 113 reflects and deflects the laser light L1 or L2 in the main scanning direction. The light is reflected by a mirror 116 provided on the optical path extending in the main scanning direction, and the arrow on the scanned surface of the film F conveyed (sub-scanned) by the conveying device 142 in the arrow Y direction. Main scanning is repeatedly performed in the X direction. In this case, each time one main scan is completed,
The laser light is switched in the order of L1 → L2 → L1 → L2 for each scanning line. In this manner, scanning is performed over the entire surface to be scanned on the film F by the laser light L1 or L2 in a pattern as shown in FIG. Note that fθ
The cylindrical lens of the lens 114 causes the incident laser light L1 or L2 to converge on the surface to be scanned of the film F only in the sub scanning direction.

As described above, in the laser beam exposure apparatus 120 shown in FIG. 5, the optical path of the laser light L1 emitted from the laser light source section 125 and the optical path of the laser light L2 emitted from the laser light source section 127 are different from those of the related art. Since it is not necessary to strictly overlap, the laser light source unit 125 and the laser light source unit 1
The adjustment of the optical system such as the mirror 27, the mirror 128a, the half mirror 128b, the condenser lens 126, and the cylindrical lens 115 becomes easy. Further, correction can be made even if the laser beam is shifted in the main scanning direction, and the laser beams in the main scanning direction do not necessarily have to match. Therefore, adjustment of the optical system such as the rotary polygon mirror 113, the cylindrical lens of the fθ lens 114, the mirror 116, and the like is also facilitated. Therefore, the laser beam exposure apparatus 120 is relatively easy to perform optical adjustment at the time of manufacturing and maintenance, and is advantageous in cost.

As described above, a latent image based on the image signal S is formed on the film F. In this case, the laser light L
1 (wavelength λ1) and the laser beam L2 (wavelength λ2) are exposed in a pattern as shown in FIG. 9. Therefore, even if an interference pattern appears in each scanning line, the interference occurs in the entire film F as described above. Unevenness can be suppressed. For this reason, interference unevenness can be made invisible in the film F after thermal development, and density unevenness can be reduced, so that image quality is improved.

Next, referring to FIG.
Modification 20 will be described. In this modification, one laser light source is used, and by giving a temperature difference to the laser light source, a wavelength difference is generated in the emitted laser light. The laser light source unit 225 shown in FIG. 6 includes a laser diode, and oscillates a laser beam having the same wavelength at the same temperature. As shown in FIG. 6, the laser light source unit 225 is provided with a temperature control element 225a and a temperature detection element 225b. The temperature control unit 225a is controlled based on the temperature detected by the temperature detection element 225b by the temperature control unit 128 so that a temperature difference occurs between the laser diodes of the laser light source unit 225.

FIG. 7 shows the temperature control element 225a in more detail. The laser diode chip 227 is directly attached to the temperature control element 225a. Further, a temperature detecting element 225b is arranged near the laser diode chip 227 of the temperature control element 225a. Further, a fin 226 is attached to the temperature control element 225a.

A laser diode is related to its oscillation wavelength.
For example, as shown in FIG. 13, assuming that there is a temperature dependency, for example, the oscillation wavelength has a characteristic of increasing at a rate of 0.3 nm / ° C.
In the case of 0 μm, since the necessary wavelength difference Δλ (= λ1−λ2) is 0.53 nm, the necessary temperature difference ΔT is 0.53
/0.3≒1.8° C. As shown in FIG. 13, when the wavelength becomes λ1 at the temperature t1 and becomes the wavelength λ2 at the temperature t2, the temperature controller 128 makes the temperatures t1 and t2 (temperature difference ΔT = t2−t).
By controlling the temperature control element 225a so as to satisfy 1) and switching the temperature control element 225a each time the main scanning is completed, the laser light source 225 outputs the laser light L1 or L
2 can be emitted. The same effect as in the case of FIG. 5 can be obtained.

Note that a Peltier element or the like can be used as a temperature control element, and a thermocouple, a thermistor, or the like can be used as a temperature detection element, but is not limited thereto. Also,
The laser light source section does not necessarily have to oscillate laser light of the same wavelength at the same temperature. If the laser light section does not have the same wavelength at the same temperature, the laser light source section is heated in the same manner as described above so that a predetermined wavelength difference is obtained. What is necessary is just to give a difference.

Since there is one laser light source, the configuration of the optical system such as the laser light source unit 225, the condenser lens 126, the cylindrical lens 115, the rotary polygon mirror 113, the cylindrical lens of the fθ lens 114, the mirror 116, etc. is simple. Thus, optical adjustment at the time of manufacturing and maintenance becomes easy, which is advantageous in terms of cost, and wavelength selection as in the case of a plurality of laser light sources becomes unnecessary.

An example of the temperature control of the laser diode chip as described above will be described with reference to FIG. The laser diode chip temperature control device shown in FIG. 15 includes a laser diode 231 for emitting laser beams having different wavelengths λ1 and λ2 to the photosensitive material F, a lens 232 provided in front of the laser diode 231; Different wavelength λ3
A laser diode 237 for emitting a laser beam, a lens 238 provided in front of the laser diode 237, a control device 239 for controlling the laser diode 237 for temperature control, and wavelengths λ1 and λ2 from the laser diode 231. A wavelength-selective half-mirror-233 such as a dichroic mirror for transmitting the laser beam and reflecting the laser beam of wavelength λ3 from the temperature controlling laser diode 237 toward the surface of the laser element 231a of the laser diode 231;

The laser beam of wavelength λ3 is supplied from the temperature controlling laser diode 237 to the lens 238 and the half mirror 2.
By condensing light on the surface of the laser element 231a via the lens 33 and the lens 232, the temperature of the surface of the laser element 231a can be increased. The surface temperature is set to, for example, the temperatures t1 and t2 in FIG.
The controller 23 controls the intensity (light amount) of the laser beam from
9 to be changed. Thereby, the wavelength of the laser beam emitted from the laser element 231a of the laser diode 231 can be changed to λ1 and λ2 as shown in FIG. The laser beam for temperature control has a wavelength (λ
3) is significantly different from the wavelength (λ1, λ2) of the laser beam, so that even if the light of λ3 is directly injected into the exposure laser light source,
There is no adverse effect without laser oscillation noise. These wavelengths are, for example, λ1 = 0.8 μm, λ2 = 0.800
When it is 53 μm, λ3 = 0.660 μm.

Next, the film F will be described. FIG. 10 is a cross-sectional view of the film F, schematically illustrating a chemical reaction in the film F during exposure. FIG. 11 is a cross-sectional view similar to FIG. 10, schematically showing a chemical reaction in the film F during heating. In the film F, a photosensitive layer mainly composed of polyvinyl butyral is formed on a support (base layer) made of PET, and a protective layer made of cellulose butyrate is further formed thereon. In the photosensitive layer, silver behenate (Beh. A) was used.
g), a reducing agent and a toning agent.

When the film F is irradiated with the laser beam L from the laser beam exposure device 120 during the exposure,
As shown in FIG. 0, silver halide grains are exposed to the area irradiated with the laser beam L, and a latent image is formed. On the other hand, when the film F is heated to a temperature equal to or higher than the minimum thermal development temperature, FIG.
As shown in FIG. 1, silver ions (Ag ⁺ ) are released from silver behenate, and behenic acid that has released silver ions forms a complex with the toning agent. Thereafter, silver ions are diffused, and the reducing agent acts with the exposed silver halide grains as nuclei to form a silver image by a chemical reaction. As described above, the film F contains the photosensitive silver halide grains, the organic silver salt, and the silver ion reducing agent, and is not substantially thermally developed at a temperature of 40 ° C. or lower, and is not substantially developed at a temperature of 80 ° C. or higher. Thermal development is performed at a temperature higher than the temperature.

The light-sensitive silver halide used in the heat-developable material is typically 0.75 to 25 with respect to the organic silver salt.
mol% can be used, preferably
It can be used in the range of 2 to 20 mol%. Further, it is preferable that the film F contains the organic acid silver in an amount of 4 times or more of the silver halide grains in the photosensitive layer. The average grain size of the silver halide grains is 0.1 μm.
It is as follows.

The silver halide may be silver bromide, silver iodide, silver chloride, silver bromoiodide, silver chlorobromoiodide,
Any photosensitive silver halide such as silver chlorobromide may be used. The silver halide may be in any form that is photosensitive, including, but not limited to, cubic, orthorhombic, tabular, tetrahedral, and the like.

Organic silver salts are any organic materials that contain a source of silver on reduction. Organic acids, especially long chain fatty acids (10
-30 carbon atoms, preferably 15-28 carbon atoms)
Are preferred. When the ligand is 4.0 to 10.0 overall
It is preferable that the organic or inorganic silver salt complex has a certain stability between the two. And about 5 times the weight of the image recording layer
It is preferably about 30%.

The organic silver salt which can be used in the heat developing material is a silver salt which is relatively stable to light, and is composed of an exposed photocatalyst (for example, silver halide for photography) and the presence of a reducing agent. Is a silver salt that forms a silver image when heated to a temperature of 80 ° C. or higher.

Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. They include silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include silver behenate, silver stearate and the like. Silver salts with halogen atoms or hydroxyl in aliphatic carboxylic acids can also be used effectively. Silver salts of compounds having a mercapto or thione group and derivatives thereof can also be used. Further, a silver salt of a compound having an imino group can be used.

The reducing agent for the organic silver salt may be any material capable of reducing silver ions to metallic silver, and is preferably an organic material. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful. However, phenol reducing agents are preferred. The reducing agent is 1 to 3 in the image recording layer.
It should be present at 10% by weight. In a multi-layer configuration,
If the reducing agent is added to a phase other than the emulsion layer, a slightly higher proportion, about 2 to 15% by weight, is more desirable.

[0075]

EXAMPLE A film F described below was exposed and thermally developed by the apparatus shown in FIGS. 5 and 6 according to the above-described embodiment, and no density unevenness possibly caused by the occurrence of interference unevenness was found. Hereinafter, the production of the film F will be described.

A silver halide-silver behenate dry soap was prepared by the method described in US Pat. No. 3,839,049. The silver halide had 9 mole% of the total silver, while silver behenate had 91 mole% of the total silver.
The silver halide has 0.055% 2% iodide.
It was a μm silver bromoiodide emulsion.

The heat-developable emulsion was homogenized with 455 g of the above-mentioned silver halide-silver behenate dry soap, 27 g of toluene, 1918 g of 2-butanone, and polyvinyl butyral (B-79 manufactured by Monsanto). The homogenized heat-developed emulsion (698 g) and 60 g of 2-butanone were cooled to 12.8 ° C. while stirring. Pyridinium hydrobromide perbromide (0.92 g) was added and stirred for 2 hours.

3.25 ml of a calcium bromide solution (CaBr (1 g) and 10 ml of methanol) were added, followed by stirring for 30 minutes. Further, polyvinyl butyral (158 g; B-79 manufactured by Monsanto) was added, and 20
Stirred for minutes. The temperature was raised to 21.1 ° C. and the following was added with stirring over 15 minutes. 3.42 g of 2- (tribromomethylsulfone) quinoline, 28.1 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, 5-methylmercaptobenzimidazole Solution containing 0.545 g

41.1 g, 2- (4-chlorobenzoyl) benzoic acid 6.12 g S-1 (sensitizing dye) 0.104 g methanol 34.3 g isocyanate (Desmoder N3300, manufactured by Mobay) 2.14 g tetra Chlorophthalic anhydride 0.97 g Phthalazine 2.88 g The dye S-1 has the following structure.

Embedded image An active protection topcoat solution was prepared using the following components: 2-butanone 80.0 g methanol 10.7 g cellulose acetate butyrate (CAB-171-155, manufactured by Eastman Chemicals)

8.0 g 4-Methylphthalic acid 0.52 g MRA-1, Mottle reducing agent, N-ethylperfluorooctanesulfonylamide ethyl methacrylate / hydroxyethyl methacrylate / acrylic acid Tertiary polymer with a weight ratio of 70:20:10 0 .80g

This heat-developable emulsion and tobcoat were simultaneously coated on a 0.18 mm blue polyester film base. The knife coater was set up with two bars or knives coating simultaneously at a distance of 15.2 cm. The silver trip layer and the top coat were multi-layer coated by pouring the silver emulsion on the film prior to the rear knife and the top coat on the film prior to the front bar.

The film was then pulled forward so that both layers were coated simultaneously. This was obtained by performing the multilayer coating method once. The coated polyester base was dried at 79.4 ° C. for 4 minutes. As the knife, as dry coating weight per 1 m ² for the silver layer is 23g, then dry coating weight per 1 m ² is adjusted so as to be 2.4g for the top coat Was. The optical path length determined from the dry thickness and refractive index of these layers and the thickness and refractive index of the film base as the support is 6.
It was 00 μm.

[0083]

According to the present invention, it is possible to provide a laser beam exposure apparatus in which the optical adjustment is simple, the loss of the light amount is suppressed, and the density does not fluctuate due to interference unevenness.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a film for explaining the principle of the present invention.

2A is a diagram showing the wavelength (λ1) and phase of a laser beam at an incident point 5 of incident light in FIG. 1; FIG. 2A is a diagram showing the wavelength (λ2) and phase of a laser beam at an incident point 6 of reflected light; FIG. 1B is a diagram showing the same phase as FIG. 1A), and FIG. 1C is a diagram showing a wavelength (λ2) and a phase (a phase opposite to FIG. 1A) of the laser beam at the incident point 6 of the reflected light.

FIG. 3 is a front view of the heat developing device according to the embodiment of the present invention.

FIG. 4 is a left side view of the heat developing device according to the embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating a configuration of a laser beam exposure device of the thermal developing device of FIG. 3;

FIG. 6 is a schematic view showing a modification of the laser beam exposure apparatus.

FIG. 7 is a side view showing the laser light source unit and the temperature control element of the laser beam exposure apparatus of FIG. 6 in more detail.

FIG. 8 is a diagram showing two different light quantity-wavelength characteristics in the present embodiment.

FIG. 9 is a diagram showing an irradiation pattern for invisible interference unevenness in the present embodiment.

FIG. 10 is a cross-sectional view of the film F according to the present embodiment, schematically showing a chemical reaction in the film F during exposure.

FIG. 11 is a cross-sectional view similar to FIG. 10, schematically showing a chemical reaction in the film F during heating.

FIGS. 12A and 12B are conceptual diagrams illustrating a relationship between a cross section of a film and a laser beam for explaining a problem of the related art.

FIG. 13 is a diagram conceptually showing a wavelength change due to a temperature of a laser diode.

FIG. 14 is a diagram showing a modification of the irradiation pattern for making the interference unevenness invisible in the present embodiment.

FIG. 15 is a schematic diagram of a temperature control device for a laser element of a laser light source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film support 2 Film photosensitive layer 100 Thermal developing device 110 Storage part 120 Laser beam exposure apparatus 130 Developing part 125,127,225 Laser light source part 225a Temperature control element 225b Temperature detection element 128 Temperature control part 129 Light modulation element 113 Rotating polygon mirror 142 Carrier F Film D1 Thickness of film support n1 Refractive index of support D2 Thickness of photosensitive layer of film n2 Refractive index of photosensitive layer λ1 Wavelength of laser beam λ2 Wavelength of another laser beam

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H106 AA72 BA91 2H112 AA03 BC32 5F072 AB13 RR01 TT27 YY20

Claims (32)

[Claims] 1. A laser beam exposure apparatus for irradiating a laser beam from a laser light source to a photosensitive material having at least one support layer or photosensitive layer that is transmissive or semi-transmissive for a wavelength to be used. A beam irradiation area formed by one scanning line or a plurality of continuous scanning lines irradiated by the laser beam is defined as one linear region, and a light amount-wavelength characteristic is defined between adjacent linear regions. Irradiating the photosensitive material with a different laser beam. 2. The light amount-wavelength characteristic is different due to a pattern of density unevenness being reversed between the linear region and an adjacent linear region. 3. The laser beam exposure apparatus according to claim 1. 3. The laser beam exposure apparatus according to claim 1, wherein the linear region and the adjacent linear region are in a range where interference unevenness is invisible. 4. The laser beam exposure apparatus according to claim 1, wherein the number of the laser light sources is one. 5. The laser beam exposure apparatus according to claim 4, wherein the one laser light source irradiates the photosensitive material by switching a light quantity-wavelength characteristic for each of the adjacent linear regions. 6. The laser beam exposure apparatus according to claim 1, wherein the number of the laser light sources is plural. 7. The laser beam exposure apparatus according to claim 6, wherein the plurality of laser light sources having different light quantity-wavelength characteristics are switched between the adjacent linear regions to irradiate the photosensitive material. . 8. The laser beam exposure apparatus according to claim 1, wherein the photosensitive material is a material that easily interferes. 9. The method according to claim 1, wherein the light amount-wavelength characteristic is changed while changing the temperature of the laser light source over a predetermined range while exposing the photosensitive material.
The laser beam exposure apparatus according to claim 1. 10. The method according to claim 1, wherein the laser light source whose light amount-wavelength characteristic is changed by changing the temperature of the laser light source is irradiated to the photosensitive material by switching between the adjacent linear regions. The laser beam exposure apparatus according to claim 9. 11. The laser beam exposure apparatus according to claim 9, wherein the modulation is performed for each of the linear regions. 12. The laser light source includes a laser element,
The laser beam exposure apparatus according to any one of claims 9 to 11, wherein a temperature control member is directly coupled to the laser element. 13. The method according to claim 9, wherein the modulation is performed by injecting a light beam for temperature modulation of another wavelength into the laser light source and modulating the light amount of the light beam.
12. The laser beam exposure apparatus according to any one of items 11 to 11. 14. The laser beam exposure apparatus according to claim 9, wherein the modulation is a random temperature modulation. 15. The modulation according to claim 9, wherein the modulation is performed between binary temperatures such that the interference pattern is reversed.
15. The laser beam exposure apparatus according to any one of items 14 to 14. 16. A laser beam exposure apparatus which irradiates a laser beam from a laser light source to a photosensitive material having at least one support layer or photosensitive layer which is transmissive or translucent to the wavelength to be used. A beam irradiation area composed of one pixel or a plurality of continuous pixels irradiated by the laser beam is defined as one pixel area, and the light quantity-wavelength characteristics of the irradiation beam differ between the adjacent pixel areas. A laser beam exposure apparatus. 17. The light amount-wavelength characteristic is different due to a pattern of density unevenness being inverted between the pixel area and an adjacent pixel area. Laser beam exposure equipment. 18. The pixel area according to claim 16, wherein the pixel area is a range in which interference unevenness is invisible.
8. The laser beam exposure apparatus according to 7. 19. The laser beam exposure apparatus according to claim 16, wherein one laser light source is provided. 20. The laser beam exposure apparatus according to claim 19, wherein said one laser light source irradiates said photosensitive material by switching light quantity-wavelength characteristics for each of said adjacent pixel areas. 21. The laser beam exposure apparatus according to claim 16, wherein the number of the laser light sources is plural. 22. The laser beam exposure apparatus according to claim 21, wherein the plurality of laser light sources having different light amount-wavelength characteristics are switched for each of the adjacent pixel areas to irradiate the photosensitive material. 23. The laser beam exposure apparatus according to claim 16, wherein the photosensitive material is a material that easily interferes. 24. The method according to claim 16, wherein the light amount-wavelength characteristic is changed by changing the temperature of the laser light source over a predetermined range while exposing the photosensitive material.
25. The laser beam exposure apparatus according to any one of items 24 to 24. 25. The photosensitive material, wherein the laser light source whose light quantity-wavelength characteristic is changed by changing the temperature of the laser light source is switched for each of the adjacent pixel areas and irradiates the photosensitive material. A laser beam exposure apparatus according to claim 24. 26. The laser beam exposure apparatus according to claim 25, wherein the modulation is performed for each of the pixel areas. 27. The laser light source includes a laser element,
27. The laser beam exposure apparatus according to claim 25, wherein a temperature control member is directly connected to the laser element. 28. The laser beam exposure apparatus according to claim 1, wherein said photosensitive material is a silver halide photosensitive material. 29. The laser beam exposure apparatus according to claim 1, wherein said laser beam exposure apparatus records an image by amplitude modulation. 30. The laser beam exposure apparatus according to claim 6, wherein the plurality of laser light sources are selected such that a difference between central peak wavelengths substantially matches a desired wavelength difference. 31. A laser beam from the laser light source is monitored, its wavelength or wavelength difference is detected by a sensor, and when the wavelength deviates from a predetermined wavelength difference, the deviation is fed back to set the temperature of the laser light source. 25. The laser beam exposure apparatus according to claim 9, wherein the laser beam exposure apparatus is changed. 32. The plurality of laser light sources are selected from different standard lasers of which the difference between the center peak wavelengths substantially matches a desired wavelength difference.
3. The laser beam exposure apparatus according to claim 1.