JP3770433B2 - Image forming apparatus - Google Patents

Description

【００３８】
【化２】

【００３９】
【化３】

【００４０】
（素材固体微粒子分散液の調製）
テトラクロロフタル酸、１，１−ビス（２−ヒドロキシ−３，５−ジメチルフェニル）−３，５，５−トリメチルヘキサン、トリブロモメチルフェニルスルホンについて固体微粒子分散物を調製した。
テトラクロロフタル酸に対し、ヒドロキシプロピルメチルセルロース０．８１ｇと水９４．２ｍｌを添加して良く攪拌してスラリーとして１０時間放置した。その後、平均直径０．５ｍｍのジルコニア製ビーズを１００ｍｌ用意し、スラリーと一緒にベッセルに入れ、分散機（１／４Ｇサンドグラインダーミル：アイメックス(株)製）で５時間分散してテトラクロロフタル酸の固体微粒子分散液を得た。粒子径は７０wt％が１．０μｍ以下であった。その他の素材については適宜分散剤の使用量、および所望の平均粒子径を得るために分散時間を変更し、それぞれの素材についての固体微粒子分散液を得た。
【００４１】
（染料を含有するポリマー微粒子分散物の調製）
下記染料Ａ（２ｇ）、メチルメタクリレート−メタクリル酸共重合体（８５：１５）（６ｇ）、および酢酸エチル４０ｍｌからなる溶液を６０℃に加温、溶解した後、ポリビニルアルコール５ｇを含む水溶液１００ｍｌに加え、高速攪拌機（ホモジナイザー、日本精機製作所製）にて１２０００ｒｐｍ、５分間、微細分散して平均粒径０．３μｍのポリマー微粒子乳化分散物Ｐを得た。
【００４２】
【化４】

【００４３】
（乳剤層塗布液の調製）
先に調製した有機銀微結晶分散物（銀１mol 相当）に対し、ハロゲン化銀粒子をハロゲン化銀１０mol ％／有機酸銀相当と、以下のバインダーおよび現像用素材を添加して乳剤塗布液とした。
バインダー：
ラックスター3307B （大日本インキ化学工業(株)製；SBR ラテックス）４３０ｇ
現像用素材：
テトラクロロフタル酸、５ｇ相当の上記分散物
１，１−ビス（２−ヒドロキシ−３，５−ジメチルフェニル）−３，５，５−トリメチルヘキサン、９８ｇ相当の上記分散物
フタラジン、９．２ｇ
トリプロモメチルフェニルスルホン、１２ｇ相当の上記分散物
４−メチルフタル酸、７ｇ
染料：
上記染料Ａ、４ｇ相当の上記染料含有ポリマー微粒子分散物
【００４４】
上記において用いたラックスター3307B は、スチレン−ブタジエン系コポリマーのポリマーラテックスであり、分散粒子の平均粒径は、０．１μｍ〜０．１５μｍ程度である。
【００４５】
（乳剤面保護層塗布液の調製）
イナートゼラチン１０ｇに対し、界面活性剤Ａを０．２６ｇ、界面活性剤Ｂを０．０９ｇ、シリカ微粒子（平均粒径２．５μｍ）０．９ｇ、１，２−（ビスビニルスルホニルアセトアミド）エタン０．３ｇ、水６４ｇを添加して乳剤面保護層塗布液とした。
【００４６】
【化５】

【００４７】
（染料分散物の調製）
酢酸エチル３５ｇに対し、下記染料Ｂを０．８ｇ添加して攪拌して溶解した。その液にあらかじめ溶解したポリビニルアルコール（ＰＶＡ−２１７）６重合％溶液を８５ｇ添加し、５分間ホモジナイザーで攪拌した。その後、酢酸エチルを脱溶媒で揮発させ、最後に水で希釈し、染料分散物を調製した。
【００４８】
【化６】

【００４９】
（固体塩基微粒子分散物の調製）
下記固体塩基、２６ｇに対し、ポリビニルアルコール（ＰＶＡ−２１５）２ｇ水溶液を２３４ｇ添加して良く攪拌してスラリーとして１０時間放置した。その後、経基金直径０．５ｍｍのジルコニア製ビーズを１００ｍｌ用意し、スラリーと一緒にベッセルに入れ、分散機（１／４Ｇサンドグラインダーミル：アイメックス(株)社製）で５時間分散して固体塩基微粒子分散液を得た。
【００５０】
【化７】

【００５１】
（バック面塗布液の調製）
１０％ゼラチン溶液、３８ｇに対し、先に調製した染料分散物２０ｇ、固体塩基微粒子分散物２０ｇ、水３５ｇを添加してバック面塗布液とした。
【００５２】
（バック面保護層塗布液の調製）
イナートゼラチン１０ｇに対し、前記の界面活性剤Ａを０．２６ｇ、界面活性剤Ｂを０．０９ｇ、１，２−（ビスビニルスルホニルアセドアミド）エタン０．３ｇ、シルデックスＨ１２１（洞海化学社製真球シリカ、平均サイズ１２μｍ）０．４ｇ、水６４ｇ添加してバック面保護膜層とした。
【００５３】
（塗布試料の作成）
上記のように調製した乳剤層塗布液に感光層添加染料を１７５μｍポリエチレンテレフタレート支持体上に塗布銀量が２．２ｇ／ｍ² となるように調節して塗布した後、乳剤塗布層上に乳剤面保護層塗布液をゼラチンの塗布量が１．８ｇ／ｍ² となるように塗布した。乾燥後、乳剤層と反対の面上にバック面塗布液を染料Ｂの塗布量が５６ｍｇ／ｍ² となるように塗布し、さらに、バック面塗布層上にバック面保護層塗布液をゼラチンの塗布量が１．８ｇ／ｍ² となるように塗布し、試料を作成した。
【００５４】
【発明の効果】
以上の説明により明らかなように、本発明による画像形成装置にあっては、レーザビームの波長域で干渉の起りやすい材料上に画像記録するに際し、干渉縞の発生を極力防止し、非視認化することにより、より鮮明な画像データを得ることができる。
【図面の簡単な説明】
【図１】本発明が適用される画像形成装置の概略図である。
【図２】本発明にかかる画像露光部の概略図である。
【図３】記録材料内でのレーザ反射光により生ずる干渉縞の説明図である。
【図４】層内に入光したレーザ光の反射形態を示す説明図である。
【符号の説明】
１０ 画像形成装置
１２ 記録材料供給部
１６ 画像露光部
１８ 熱源像部
５０ レーザ光源
λ 波長
Δλ スペクトル幅
Ａ 記録材料[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus using a photosensitive material on which an image is recorded by laser exposure.
[0002]
[Prior art]
Conventionally, as a digital radiography system, an image recording apparatus for recording medical images such as CT, MR, etc., a wet system that obtains a reproduced image by performing wet processing after photographing or recording on a silver salt photographic photosensitive material has been used. Yes.
On the other hand, in recent years, a recording apparatus using a dry system that does not include a wet process has attracted attention. As such a recording apparatus, for example, there is an image recording apparatus using a photothermographic material film (hereinafter referred to as “recording film”).
[0003]
Also in the image recording apparatus of this dry system, when image recording is performed, a latent image is formed on the recording film by irradiating the recording film with laser light (exposure). Then, the latent image is developed by heating the recording film on which the latent image is formed. The exposure is generally performed by scanning the laser (main scanning) while controlling the output of the laser according to separately captured image data. Of course, at this time, the recording film is also moved (sub-scanned) in a predetermined direction.
Examples of the image recording apparatus for such a photothermographic material include those described in International Publication No. WO95 / 31754 and International Publication No. WO95 / 30934.
[0004]
A conceptual diagram of a conventional exposure unit 16 in such an image recording apparatus is shown in FIG. The exposure unit is a known light beam scanning device that deflects a light beam L modulated in accordance with an image signal in the main scanning direction (direction b in FIG. 2) and enters a predetermined recording position X, and is a recording material. A laser light source 50 that emits a light beam L in a narrow band wavelength range corresponding to the spectral sensitivity characteristic of A, a recording control device (driver) 52 that drives the light source 50, a normal mirror 53, and an optical deflector. A polygon mirror 54, an fθ lens 56, and a falling cylindrical mirror 58 are provided.
[0005]
In addition to this, the exposure unit is arranged in a known light beam scanning device such as a collimator lens, a beam expander, a surface tilt correction optical system, an optical path adjustment mirror, or the like that shapes the light beam L emitted from the light source. Various optical system members to be arranged are arranged as necessary.
[0006]
Here, as an exposure method, image recording is generally performed by pulse width modulation. The recording control device (driver) 52 drives the laser light source 50 by performing pulse width modulation according to the recorded image, and emits the light beam L subjected to pulse width modulation according to the recorded image. The light beam L emitted from the light source 50 is deflected in the main scanning direction by the polygon mirror 54, adjusted so as to form an image at the recording position X by the fθ lens 56, and the optical path is changed by the cylindrical mirror 58 to change the recording material. Incident at an angle near to the recording position X of A.
[0007]
On the other hand, the sub-scanning conveying unit has a pair of conveying ports 60 and 62 arranged with the recording position X (scanning line) in between, and the recording material A is recorded by the conveying roller pair 60 and 62. While being held at position X, it is conveyed in the sub-scanning direction (arrow a direction in FIG. 7) orthogonal to the main scanning direction.
Here, as described above, since the light beam L that has been pulse-width modulated in accordance with the recorded image is deflected in the main scanning direction, the recording material A is two-dimensionally scanned and exposed by the light beam, and a latent image is obtained. Is recorded.
[0008]
[Problems to be solved by the invention]
The recording material A used in the above image forming apparatus is, for example, a photothermographic material, as shown in FIG. 4, specifically on a base film made of a PET material and having a thickness of several hundreds of μm. The emulsion layer Em is about μm to several tens of μm, and the surface thereof is coated with the protective layer PC, and the back surface of the base film is coated with the backcoat layer BC and the antihalation layer AH. And, compared with the layer structure of the usual photosensitive film material, since it is designed with a particularly high sharpness in the case of a thing used for medical purposes, each layer is thin and the emulsion layer Em is made finer. As a result, the layer itself becomes transparent and light tends to go straight.
[0009]
On the other hand, the beam diameter of the laser beam incident on the recording material A is 50 to 120 μm, and when reflecting the boundary surface of each layer, each layer is thin enough to cause interference due to reflection twice within the same beam diameter. As shown in an enlarged view of a portion of Fig. 5, the interference in the emulsion layer Em is remarkable.
As a result, density unevenness called interference fringes occurs in the obtained image, which causes problems in image diagnosis and impairs commerciality.
[0010]
As a conventional device for preventing the occurrence of the above interference fringes, for example, in Japanese Patent Application Laid-Open No. 5-113548, the incident angle of the laser beam is slanted to make the reflection angle wide and the optical path length long, Although measures are taken to prevent interference by preventing the reflected light from traveling in the same direction as the incident light, the occurrence of interference is inevitable if the emulsion layer and the base layer are thin as described above.
[0011]
In addition, as shown in Japanese Patent Laid-Open No. 7-253554, a method of using a circularly polarized light by arranging a ¼λ plate in the optical path is not effective, and a high frequency as shown in Japanese Patent Laid-Open No. 60-14567. In the case of superimposing use, there is a drawback that the output of the laser diode can only be used up to 1/2 of the rated output.
[0012]
The object of the present invention is to solve the above-mentioned problems. The object of the present invention is to provide a laser light source spectral width and an emulsion of a recording material when recording an image on a material that is susceptible to interference in the wavelength region of the laser beam as described above. An object of the present invention is to provide an image forming apparatus capable of obtaining a clearer and more excellent diagnostic property by preventing the occurrence of interference fringes as much as possible by matching with the layer thickness and making it invisible.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an image forming apparatus including an image exposure unit that exposes an image and data on an image recording material that easily causes interference in a wavelength region of a laser beam.
The spectral width Δλ of the laser light source of the image exposure unit is expressed by the following formula: Δλ = λ ² / (λ + 4 nt / cos θ), where θ is the angle of light traveling in the emulsion layer relative to the normal, and n is the emulsion. The refractive index of the layer, t: the thickness of the emulsion layer, and λ: the center wavelength of the laser light source).
[0014]
More specifically, when t is 10 to 30 μm and n is 1.4 to 2.0, the center wavelength λ of the laser light source is set to 633 to 830 nm.
In other words, the present invention utilizes the fact that the phases of the spectral components of the reflected light of the laser beam are relatively half-wavelength shifted to cancel each other out, and is based on the following theoretical basis.
[0015]
First, as shown in FIG. 4, an optical path length L and a node N that reciprocate through the emulsion layer when a laser beam having a wavelength λ is incident on a layer having a refractive index n and a thickness t at a predetermined angle θ are as follows: expressed.
Optical path length: L = 2nt / cos θ
Number of nodes: N = L / λ
Different wavelengths λ ′ : (λ−Δλ) (Δλ: spectral width)
(Λ 'is a wavelength that can be offset with a half wavelength as described above and is in the spectral width range of λ)
When the number of nodes becomes N + 1/2, the light emission position (1) shown in FIGS. 3 and 4 weakens and no interference fringes are generated.
L / λ ′ = L / (λ−Δλ) = L / λ + 1/2
From this,
Δλ = λ ² / (λ + 2L) = λ ² / (λ + 4 nt / cos θ)
[0016]
Therefore, if the spectral width of the laser light source is wider than Δλ calculated by the above formula, the generation of interference fringes is suppressed.
Since the thickness t and the refractive index n of the emulsion layer in the recording material are known, the spectral width of the manufactured conductor laser is measured in advance, and a semiconductor laser that satisfies this condition is selected and assembled to the light source. It will be a thing.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a schematic diagram of an image forming apparatus of a dry system according to an embodiment of the present invention. In the figure, an image forming apparatus 10 uses a photothermographic material or a photothermographic recording material (hereinafter referred to as recording material A) that does not require a wet development process, and performs scanning exposure with a light beam L composed of laser light. This is an apparatus for obtaining a visible image by performing thermal development after forming a latent image by imagewise exposing the recording material A. The image forming apparatus 10 basically includes a recording material supply unit 12, a width adjustment unit 14, an image exposure unit 16, and a heat development unit 18 in the order of the recording material A conveyance direction.
[0018]
The supply unit 12 has two stages, and the recording material A loaded into each stage 22 and 24 via the magazine 100 is formed into, for example, a B4 plate, an A4 plate, and the like. Can be selected.
As the recording material A, a photothermographic material is used. Conventionally, the photothermographic material is a recording material that records (exposes) an image with a single laser beam and then develops the color by heat development. The sheet-like recording material A is usually a predetermined unit such as 100 sheets. A package (sheet bundle) is formed into a package 80 by being wrapped in a bag or a belt.
[0019]
The package 80 is accommodated in a magazine 100 corresponding to each plate and loaded into the supply unit 12 of the image forming apparatus 10.
Then, when the apparatus is switched on, the following series of processing operations are executed.
First, the recording material A of the magazine 100 selected by the suction cups 26 and 28 of the single-wafer mechanism with the lid of the magazine 100 open is taken out from the top.
[0020]
The taken recording material A is conveyed to the downstream narrowing section 14 while being guided by the supply roller pair 30, 32, the conveyance roller pair 34, 36, and the conveyance guides 38, 40, 42 located downstream in the conveyance direction. Is done.
The width aligning unit 14 aligns the recording material A in the main scanning direction in the downstream image exposure unit 16 by aligning the recording material A in a direction orthogonal to the transport direction (hereinafter referred to as a radial direction). This is a part where a so-called side resist is taken and the recording material A is conveyed to the downstream image exposure unit 16 by the conveying roller pair 44.
[0021]
The downstream image exposure unit 16 (hereinafter referred to as the exposure unit 16) is a part that exposes the recording material A imagewise by light beam scanning exposure, and includes an exposure unit 46 and a sub-scanning conveying unit 48. Yes. The exposure unit 16 will be described in detail later.
The recording material A on which the latent image is recorded in the exposure unit 16 is then transported by the pair of transport rollers 64 and 66 and transported to the heat developing unit 18.
[0022]
The thermal development unit 18 is a part that heats the recording material A to perform thermal development so that the latent image becomes a visible image, and includes a heating drum 68, an endless belt 70, and a peeling claw 72.
The heating drum 68 is a drum having a built-in heating light source such as a halogen lamp or a heat source such as a heater. The surface of the heating drum 68 is heated and held at a temperature corresponding to the heat development temperature of the recording material A. The recording material A is nipped and conveyed together with the endless belt 70 by rotating to the center.
[0023]
The endless belt 70 is stretched around four rollers 74 a, 74 b, 74 c and 74 d and pressed so as to be wound around the heating drum 68.
The peeling claw 72 peels the recording material A from the heating drum 68, and is configured to lightly contact and detach from the heating drum 68 corresponding to the conveyance of the recording material A by the heating drum 68.
[0024]
The recording material A carried into the heat developing unit 18 by the conveyance roller pair 66 is nipped and conveyed by the process belt 70 and the rollers 76 and 78, and between the heating drum 68 and the process belt 70. The latent image that is carried in and is heat-developed by the heating drum 68 while being conveyed according to the rotation of the heating drum 68 and recorded by exposure becomes a visible image.
[0025]
When the leading end of the recording material A is conveyed in the vicinity of the peeling claw 72, the peeling claw 72 lightly contacts the heating drum 68 and enters between the heating drum 68 and the recording material A, and the recording material A is heated to the heating drum. The recording material A that has been peeled off 68 and peeled off from the heating drum 68 by the peeling claw 72 is conveyed outside the apparatus and discharged to the tray 80.
[0026]
FIG. 2 shows an image exposure unit 16 to which the present invention is applied. In the figure, the same portions as those in FIG. 1 are denoted by the same reference numerals, and only the portions to which the description is added are described using new reference numerals.
In the figure, the image exposure unit 16 includes a laser light source 50 including a semiconductor laser 50a that outputs a laser beam L0, a collimator lens 50b that converts the laser beam into a parallel beam, and a cylindrical lens 50c.
[0027]
The laser light source 50 enters the polygon mirror 54 through the reflection mirror 52, and the laser beam is irradiated along the main scanning direction b through the fθ lens 56 and the cylindrical mirror 58 while being polarized with the rotation of the laser light source 50.
In response to the input of the image signal, the driver 52 is driven by a control unit (not shown), and the feed motor M provided on the polygon mirror 54 and the roller pair 60 is rotationally driven to control the laser beam in the main scanning direction of the recording material A. The recording material A is fed in the sub-scanning direction a while scanning in b.
As described above, while the recording material A is sequentially fed in the sub-scanning direction by the feeding of the feeding motor M, a latent image having a predetermined contour line is sequentially formed on the surface along the main scanning direction.
[0028]
Here, the spectral width emitted from the semiconductor laser 50a constituting the laser light source 50 is set to be equal to or larger than the spectral width Δλ represented by the following equation.
Δλ = λ ² / (Λ + 2L) = λ ² / (λ + 4 nt / cos θ)
Here, L is the optical path length in the emulsion layer, t is the thickness of the emulsion layer, n is its refractive index, and λ is the wavelength of the semiconductor laser 50a.
[0029]
Therefore, in the image forming apparatus according to the present invention, the generation of interference fringes due to the reflection of the laser beam in the layer due to the thin emulsion layer Em is suppressed, and the surface of the recording material A is hidden by a clear outline. An image can be formed.
Each semiconductor laser 50a to be actually used is selected by inspecting the spectrum width of each semiconductor laser in the lot of manufactured semiconductor lasers, and selecting a semiconductor laser having a spectrum width characteristic equal to or larger than Δλ. This may be an optical arrangement as shown in the figure.
[0030]
【Example】
Next, examples of the present invention will be described. However, the present invention is not limited only to the following examples.
[Example]
When a recording material having an emulsion layer thickness t = 11.5 μm and a refractive index n = 1.78 is used, the recording material is perpendicularly incident on the recording material, and the center wavelength λ of the semiconductor laser is λ = 660 nm. By substituting the value into the above equation, Δλ> 5.28 nm was obtained.
A semiconductor laser that outputs a laser beam having a spectral width satisfying this condition was selected, assembled in an optical arrangement as shown in FIG. 2, and the recording material was superimposed on the recording material, and dry development was performed.
[0031]
[Comparative example]
Dry development was carried out under exactly the same conditions as in Examples except that a semiconductor laser having a spectral width of Δλ <5.28 nm was used.
When the image samples burned on both were compared, the interference fringes were almost invisible in the example, but the interference fringes were seen in the comparative example, confirming the effect of the present invention.
[0032]
Here, the interference fringes due to the reflection of the laser beam are likely to occur because the AgX particles of the photographic photosensitive material are small (average 0.2 μm or less) and the coated silver amount of the photographic photosensitive material is small in order to improve the sensitivity ( 3 g / m <2> or less), and the absorbance of the emulsion layer of the photographic light-sensitive material is small (0.5 or less at the laser wavelength), and any of the recording materials A meets the conditions.
[0033]
The materials described in Japanese Patent Application No. 9-185724 will be described below as examples of image recording materials used in the examples of the present invention.
(Preparation of organic silver dispersion)
40 g of behenic acid, 7.3 g of stearic acid and 500 ml of water were stirred at a temperature of 90 ° C. for 15 minutes, 187 ml of 1N sodium hydroxide was added over 15 minutes, 61 ml of 1N nitric acid aqueous solution was added, and the temperature was lowered to 50 ° C. . Next, 124 ml of 1N aqueous silver nitrate solution was added over 2 minutes, and the mixture was stirred for 30 minutes. Then, the solid content was separated by suction filtration, and the solid content was washed with water until the filtrate had a conductivity of 30 μS / cm. The solid content thus obtained was handled as a wet cake without drying, and 10 g of polyvinyl alcohol (trade name: PVA-205) and water were added to the wet cake equivalent to 100 g of the dry solid content to make the total weight 500 g. Pre-dispersed with a mixer.
[0034]
Next, the pre-dispersed stock solution is adjusted to a pressure of 1750 kg / cm ² of a disperser (trade name: Microfluidizer M-110S-EH: manufactured by Microfluidics International Corporation, using a G10Z interaction chamber) The treatment was repeated three times to complete the preparation of the organic silver fine crystal dispersion having a volume weighted average diameter of 0.39 μm. The particle size was measured with Master Sizer X manufactured by Malvern Instruments Ltd.
[0035]
(Preparation of silver halide grains)
After dissolving 22 g of phthalated gelatin and 30 mg of potassium bromide in 700 ml of water and adjusting the pH to 5.0 at a temperature of 40 ° C., 159 ml of an aqueous solution containing 18.6 g of silver nitrate and an aqueous potassium bromide solution were added to pAg 7.7. While maintaining, it was added over 10 minutes by the controlled double jet method. Subsequently, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and an aqueous solution containing 8 μmol / l of dipotassium hexachloroiridate and 1 mol / l of potassium bromide were added over 30 minutes by the controlled double jet method while maintaining pAg 7.7. Thereafter, the pH was lowered to perform coagulation sedimentation, followed by desalting, and 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg 8.0. The obtained particles were cubic particles having an average particle size of 0.07 μm, a coefficient of variation in projected area diameter of 8%, and a (100) plane ratio of 86%.
[0036]
The temperature of the silver halide grains prepared above was raised to 60 ° C., and 85 μmol of sodium thiosulfate and 11 μmol or 2 μmol of 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide per 1 mol of silver. The following tellurium compound 1, 3.3 μmol of chloroauric acid and 230 μmol of thiocyanic acid were added and aged for 120 minutes.
Thereafter, the temperature was changed to 40 ° C., and the following sensitizing dye A was added to 3.5 × 10 −4 mol of silver halide with stirring, and after 5 minutes, the following compound A was added to silver halide 4 6 × 10 −3 mol was added, stirred for 5 minutes, and then rapidly cooled to 25 ° C. to prepare silver halide grains.
[0037]
[Chemical 1]

[0038]
[Chemical 2]

[0039]
[Chemical 3]

[0040]
(Preparation of raw material fine particle dispersion)
Solid fine particle dispersions were prepared for tetrachlorophthalic acid, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, and tribromomethylphenylsulfone.
To tetrachlorophthalic acid, 0.81 g of hydroxypropylmethylcellulose and 94.2 ml of water were added and stirred well and left as a slurry for 10 hours. Thereafter, 100 ml of zirconia beads having an average diameter of 0.5 mm are prepared, put in a vessel together with the slurry, and dispersed for 5 hours with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) to obtain tetrachlorophthalic acid. A solid fine particle dispersion was obtained. As for the particle size, 70 wt% was 1.0 μm or less. For other materials, the amount of dispersant used and the dispersion time were changed in order to obtain the desired average particle size, and solid fine particle dispersions for each material were obtained.
[0041]
(Preparation of polymer fine particle dispersion containing dye)
A solution comprising the following dye A (2 g), methyl methacrylate-methacrylic acid copolymer (85:15) (6 g), and 40 ml of ethyl acetate was heated to 60 ° C. and dissolved, and then dissolved in 100 ml of an aqueous solution containing 5 g of polyvinyl alcohol. In addition, it was finely dispersed with a high-speed stirrer (homogenizer, manufactured by Nippon Seiki Seisakusho) at 12000 rpm for 5 minutes to obtain a polymer fine particle emulsified dispersion P having an average particle size of 0.3 μm.
[0042]
[Formula 4]

[0043]
(Preparation of emulsion layer coating solution)
To the previously prepared organic silver microcrystal dispersion (equivalent to 1 mol of silver), silver halide grains were added to the emulsion coating solution by adding 10 mol% of silver halide / equivalent to organic acid silver, and the following binder and developing material. did.
binder:
Luck Star 3307B (Dainippon Ink Chemical Co., Ltd .; SBR latex) 430g
Development material:
Tetrachlorophthalic acid, 5 g of the above dispersion 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, 98 g of the above dispersion phthalazine, 9.2 g
Tripromomethylphenylsulfone, 12 g of the above dispersion 4-methylphthalic acid, 7 g
dye:
Dye-containing polymer fine particle dispersion equivalent to 4 g of the above dye A
Luck Star 3307B used above is a polymer latex of a styrene-butadiene copolymer, and the average particle size of the dispersed particles is about 0.1 μm to 0.15 μm.
[0045]
(Preparation of emulsion surface protective layer coating solution)
0.26 g of surfactant A, 0.09 g of surfactant B, 0.9 g of silica fine particles (average particle size 2.5 μm), 1,2- (bisvinylsulfonylacetamide) ethane 0 to 10 g of inert gelatin .3 g and 64 g of water were added to prepare an emulsion surface protective layer coating solution.
[0046]
[Chemical formula 5]

[0047]
(Preparation of dye dispersion)
0.8 g of the following dye B was added to 35 g of ethyl acetate and dissolved by stirring. 85 g of a 6% solution of polyvinyl alcohol (PVA-217) dissolved in advance in the liquid was added and stirred for 5 minutes with a homogenizer. Then, ethyl acetate was volatilized by desolvation, and finally diluted with water to prepare a dye dispersion.
[0048]
[Chemical 6]

[0049]
(Preparation of solid base fine particle dispersion)
234 g of a 2 g aqueous solution of polyvinyl alcohol (PVA-215) was added to 26 g of the following solid base, stirred well, and left as a slurry for 10 hours. Thereafter, 100 ml of a zirconia bead having a diameter of 0.5 mm is prepared, placed in a vessel together with the slurry, and dispersed for 5 hours with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) for solid base. A fine particle dispersion was obtained.
[0050]
[Chemical 7]

[0051]
(Preparation of back surface coating solution)
To the 10% gelatin solution, 38 g, 20 g of the dye dispersion prepared above, 20 g of the solid base fine particle dispersion, and 35 g of water were added to obtain a back surface coating solution.
[0052]
(Preparation of back surface protective layer coating solution)
0.26 g of surfactant A, 0.09 g of surfactant B, 0.3 g of 1,2- (bisvinylsulfonylacedoamido) ethane, Sildex H121 (Dokai Chemical Co., Ltd.) 0.4 g of true spherical silica (average size: 12 μm) and 64 g of water were added to form a back surface protective film layer.
[0053]
(Preparation of coated sample)
The emulsion layer coating solution prepared above was coated with the photosensitive layer-added dye on a 175 μm polyethylene terephthalate support so that the coating silver amount was 2.2 g / m ^2, and then the emulsion layer was coated on the emulsion coating layer. The surface protective layer coating solution was applied so that the gelatin coating amount was 1.8 g / m ² . After drying, the back surface coating solution is coated on the surface opposite to the emulsion layer so that the coating amount of Dye B is 56 mg / m ^2, and the back surface protective layer coating solution is further coated on the back surface coating layer with gelatin. A sample was prepared by coating so that the coating amount was 1.8 g / m ² .
[0054]
【The invention's effect】
As is apparent from the above description, in the image forming apparatus according to the present invention, when an image is recorded on a material that is likely to cause interference in the wavelength region of the laser beam, the generation of interference fringes is prevented as much as possible, and the image is not made visible. By doing so, clearer image data can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view of an image forming apparatus to which the present invention is applied.
FIG. 2 is a schematic view of an image exposure unit according to the present invention.
FIG. 3 is an explanatory diagram of interference fringes generated by laser reflected light in a recording material.
FIG. 4 is an explanatory view showing a reflection form of laser light incident on a layer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Recording material supply part 16 Image exposure part 18 Heat source image part 50 Laser light source (lambda) Wavelength (DELTA) (lambda) Spectral width A Recording material

Claims (1)

In an image forming apparatus including an image exposure unit that exposes an image and data on an image recording material that easily causes interference in the wavelength region of the laser beam,
The spectral width Δλ of the laser light source of the image exposure unit is expressed as follows: Δλ = λ ² / (λ + 4 nt / cos θ)
(Where θ is the angle of light traveling in the emulsion layer relative to the normal, n is the refractive index of the emulsion layer, t is the thickness of the emulsion layer, and λ is the center wavelength of the laser light source).
An image forming apparatus characterized by being set larger.

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