JPH06326832A - Picture device - Google Patents

Abstract

PURPOSE:To provide the picture device in which lighting of an undesired light to a photorecepter and its image forming are effectively prevented and a latent image with high picture quality is formed to the photorecepter or image forming of external picture information onto a solid-state image pickup element array is made uniform and sharp and an accurate electric signal corresponding to the picture information is generated from the solid-state image pickup element array. CONSTITUTION:This device is composed of a lens array 3 in which plural rod lenses 7 whose refractive index at a centre part and a peripheral part is made different are bonded in a frame 6 by an adhesives and of a picture element array 2 in which lots of picture elements 2a are arranged in a line and the lens array 3 and the picture element array 2 are arranged opposite to each other so that each of the picture elements 2a is placed on an optical axis of each of the rod lenses 7; and a refractive index of the adhesives bonding each of the rod lenses 7 into the frame 6 is selected the same as the refractive index of the peripheral part of the rod lenses 7 and the adhesives includes an optical absorbing agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus used in an image forming apparatus such as an optical printer head or an image reading apparatus such as an image sensor.

[0002]

2. Description of the Related Art A conventional image forming apparatus such as an image forming apparatus such as an optical printer head generally has a linear array of a light emitting diode element array composed of a plurality of light emitting diode elements on an electrically insulating substrate. It consists of an arrayed base plate, a lens array in which rod-shaped self-focusing lenses are linearly arranged in two rows on the frame, and fixed with an adhesive made of silicone resin, and a housing made of polycarbonate resin or the like. , The base plate and lens array in the housing,
It is manufactured by fixing each light emitting diode element so as to be located on the optical axis of each rod-shaped self-focusing lens via an adhesive.

In an optical printer head as such an image forming apparatus, each light emitting diode element of the light emitting diode element array is caused to selectively and selectively emit light in accordance with an external electric signal, and the light emitted by each light emitting diode element is emitted. It functions as an image forming apparatus by forming an image on an external photoconductor surface through a lens array and forming a latent image on the photoconductor.

The rod-shaped self-focusing lens used in the lens array of the optical printer head is made of polymethylmethacrylate (PMMA) and has 2,2,3,3-tetrafluoropropylmethacrylate diffused in the outer periphery thereof. As a result, the refractive index of the central portion is smaller than the refractive index of the outer peripheral portion, so that the light is propagated inside the self-focusing lens.

[0005]

However, in this conventional image device, since the refractive index of the outer peripheral portion of each rod-shaped lens is different from the refractive index of the adhesive for fixing each rod-shaped lens to the frame, each light emission is different. When the light emitted from the diode element is irradiated and image-formed on the external photoconductor surface through each rod-shaped lens of the lens array to form a latent image on the photoconductor, reflection of light occurs at the outer peripheral portion of each rod-shaped lens and this It is possible to form an accurate and clear latent image on the photoconductor by irradiating an image on the photoconductor together with direct light from each light emitting diode element, and as a result, irradiating and forming unnecessary light on the photoconductor. It had the drawback of not being able to.

In the above-mentioned conventional example, an image device used in an image forming device such as an optical printer head has been described as an example, but a solid-state image sensor array (CCD element array) is used.
Even in an image device used for an image reading device such as an image sensor using the image sensor, the image formation of the external image information on the solid-state image sensor array becomes nonuniform and unclear, and the solid-state image sensor array does not accurately correspond to the image information. It has a drawback that it is impossible to generate an electric signal.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and an object thereof is to effectively prevent unnecessary light from being irradiated and imaged on the photoconductor and to form a latent image with high image quality on the photoconductor. And an image device capable of forming an image of external image information on the solid-state image sensor array uniformly and clearly and generating an accurate electric signal corresponding to the image information in the solid-state image sensor array. To do.

[0008]

According to the present invention, there are provided a lens array in which a plurality of rod-shaped lenses having different refractive indexes at a central portion and an outer peripheral portion are bonded and fixed in a frame body with an adhesive, and a large number of image elements. An image device comprising an image element array mounted linearly arranged, wherein the lens array and the image element array are arranged so as to face each other so that each image element is located on the optical axis of each rod-shaped lens, The refractive index of the adhesive for fixing each rod-shaped lens inside the frame is the same as the refractive index of the outer peripheral portion of the rod-shaped lens, and the adhesive contains a light absorbing material. .

[0009]

According to the image device of the present invention, the adhesive for fixing each rod-shaped lens in the frame body has the same refractive index as the refractive index of the outer periphery of the rod-shaped lens, and the adhesive contains a light absorbing material. Therefore, the light emitted from each light emitting diode element is irradiated and image-formed on the external photoconductor surface through each rod lens of the lens array to form a latent image on the photoconductor. Even if the reflection is about to occur, the reflection is prevented by propagating the light as it is in the adhesive and being absorbed by the light absorbing material, and as a result, each rod-shaped lens receives only the direct light from each light emitting diode element as a photoconductor. It is possible to form a clear and accurate latent image on the photoconductor by irradiating the image well.

When this image device is used in an image reading device such as an image sensor, only external image information is imaged uniformly and clearly on the solid-state image sensor array, and the solid-state image sensor array corresponds to the image information. It becomes possible to generate an accurate electric signal.

[0011]

The present invention will now be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment in which the image device of the present invention is applied to an optical printer head as an image forming device, 1 is a base plate, 2 is a light emitting diode element array, 3 is a lens array, and 4 is a housing. Is.

The base plate 1 is made of an electrically insulating material such as ceramic, glass or glass epoxy, and a plurality of light emitting diode element arrays 2 are linearly mounted on the upper surface thereof.

The pace plate 1 functions as a support member for supporting the light emitting diode element array 2, and when it is made of, for example, a ceramic of aluminum oxide sintered material, alumina (Al ₂ O ₃ ) and silica ( SiO ₂ ), calcia (CaO), magnesia (MgO), etc.A suitable organic solvent is added to the raw material powder, and the solvent is mixed to form a slurry and this is adopted by the conventionally known doctor blade method or calender roll method. To obtain a ceramic green sheet (ceramic green sheet), and thereafter, the ceramic green sheet is punched into a predetermined shape and fired at a high temperature (about 1600 ° C.).

Further, the light emitting diode element array 2 mounted on the base plate 1 comprises a plurality of light emitting diode elements 2a, and the light emitting diode elements 2a individually and selectively emit light in response to an external electric signal, By irradiating the surface of the photoconductor 5 with the emitted light, a latent image for forming an image is formed on the photoconductor 5.

The light emitting diode element 2a is made of GaAsP.
-Based, GaP-based light-emitting diodes are used, for example, GaAs
In the case of P-based light-emitting diodes, as well as heating to a high temperature the GaAs substrate at furnace First AsH ₃ and (arsine) PH
A gas containing an appropriate amount of ₃ (phosphine) and Ga (gallium) is contacted to grow an n-type semiconductor GaAsP (gallium-arsenic-phosphorus) single crystal on the substrate surface, and then a GaAsP single crystal surface is grown.
A window film of Si ₃ N ₄ (silicon nitride) is deposited, and Zn (zinc) gas is exposed to the window part to remove Ga of n-type semiconductor.
It is formed by diffusing Zn into a part of an AsP single crystal to form a p-type semiconductor and having a pn junction.

In the case of a B4 size optical printer head, 2048 (8 per 1 mm) light emitting diode elements 2a are linearly arranged. Specifically, 64 light emitting diodes are set as one unit. By arranging 32 light emitting diode arrays 2 linearly, 2048 light emitting diode elements 2a are arranged on the base plate 1.

Further, the light emitting diode element 2a is provided with a lens array 3 at a certain distance above the light emitting diode element 2a, and the lens array 3 functions to irradiate the surface of the photoconductor 5 with the light emitted from each light emitting diode element 2a. Do

The lens array 3 is made of glass in a frame 6,
Rod-shaped self-focusing lens made of synthetic resin
It has a structure in which a large number of 7 are arranged linearly in two rows.
The rod-shaped self-focusing lens 7 is sandwiched between the ABS resin or FRP plate that will be the frame body 6 in two rows, and the adhesive 8 is filled and cured between the ABS resin or FRP plate and each self-focusing lens 7 to cure the frame. It is manufactured by bonding the body 6 and the self-focusing lens 7 with the adhesive 8.

Further, each rod-shaped self-focusing lens 7 of the lens array 3 is made of glass or resin such as polymethylmethacrylate (PMMA), for example, on the outer peripheral portion.
By diffusing 2,2,3,3-tetrafluoropropyl methacrylate, the refractive index of the central part is smaller than that of the outer peripheral part, which allows the light to propagate inside the self-focusing lens 7. Has become.

Further, in the lens array 3, the refractive index of the adhesive 8 for adhering and fixing the plurality of self-focusing lenses 7 in the frame 6 is the same as the refractive index of the outer peripheral portion of the self-focusing lens 7, and The adhesive 8 contains a light absorbing material.

The adhesive 8 has the same refractive index as the outer peripheral portion of the self-focusing lens 7 and contains a light absorbing material, so that the light emitted from each light emitting diode element 2a is reflected by the lens array 3 When a latent image is formed on the surface of the photoconductor 5 by irradiating and forming an image on the outer surface of the photoconductor 5 via each of the self-focusing lenses 7, even if an attempt is made to reflect light on the outer peripheral portion of each self-focusing lens 7, Reflection is prevented by propagating the light as it is into the adhesive 8 and being absorbed by the light absorbing material, so that each self-focusing lens 7 directs only the direct light from each light-emitting diode element 2a to the photoconductor 5. It is possible to form a clear and accurate latent image on the photoconductor 5 by irradiating it well.

The adhesive 8 is preferably polymethylmethacrylate (PMMA) or the like, and the light absorbing material is preferably a black pigment such as carbon black, titanium-carbon or black iron oxide. It

In addition, when the light absorbing material is contained in the adhesive 8,
When the total weight of the adhesive 8 is 100% by weight, it is difficult to completely absorb the light leaked from the side surface of the self-focusing lens 7 when it is less than 5% by weight, and when it exceeds 40% by weight, the light absorbing material is adhered. The uniform dispersion in the agent 8 becomes difficult, and the light leaked from the side surface of the self-focusing lens 7 cannot be completely absorbed. Therefore, when the total weight of the adhesive 8 is 100% by weight, the light absorbing material is 5 to 40%.
The content is preferably in the range of wt%, and more preferably in the range of 10 to 30 wt%.

Thus, according to the image device of the present invention, the plurality of light emitting diode elements 2a linearly arranged on the base plate 1 are caused to individually and selectively emit light in response to an external electric signal, and the emitted light is emitted. Photoconductor through lens array 3
It functions as an image forming device by irradiating it with 5.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the present invention. The rod-shaped self-focusing lens 7 and the adhesive 8 are , Self-focusing lens 7
Any material can be used as long as the refractive index of the outer peripheral portion and the refractive index of the adhesive 8 are the same.

In the above embodiment, the case of using the image forming apparatus such as the optical printer head has been described as an example.
The light-emitting diode element array can be replaced with a solid-state image sensor array and can be used in an image reading device such as an image sensor.

[0027]

According to the image device of the present invention, the refractive index of the adhesive for fixing each rod-shaped lens in the frame is made equal to the refractive index of the outer peripheral portion of the rod-shaped lens, and the light absorbing material is contained in the adhesive. Since the light emitted from each light-emitting diode element is irradiated and image-formed on the external photoconductor surface through each rod-shaped lens of the lens array to form a latent image on the photoconductor, in the outer peripheral portion of each rod-shaped lens Even if light is reflected, it is prevented by the light being propagated through the adhesive as it is and absorbed by the light absorbing material, and as a result, each rod-shaped lens only receives the direct light from each light emitting diode element. It is possible to irradiate the photoreceptor well and form a clear and accurate latent image on the photoreceptor.

When this image device is used in an image reading device such as an image sensor, only the external image information is imaged uniformly and clearly on the solid-state image sensor array, and the solid-state image sensor array corresponds to the image information. It becomes possible to generate an accurate electric signal.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which an image forming apparatus of the present invention is applied to an optical printer head as an image forming apparatus.

FIG. 2 is a partial plan view of a lens array used in the optical printer head shown in FIG.

[Explanation of symbols]

 1 ... Base plate 2 ... Light emitting diode array 2a ... Light emitting diode 3 ... Lens array 4 ... Housing 6 ... Frame 7 ... Rod-shaped lens 8. ···adhesive

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G02B 7/02 D

Claims (1)

[Claims] 1. A lens array in which a plurality of rod-shaped lenses having different refractive indices at the central portion and the outer peripheral portion are bonded and fixed in a frame body with an adhesive, and a large number of image elements are linearly arranged and mounted. An image device comprising an image element array, wherein the lens array and the image element array are opposed to each other so that each image element is located on the optical axis of each rod-shaped lens. An image device in which the refractive index of the adhesive agent fixed to the same is the same as the refractive index of the outer peripheral portion of the rod lens, and the adhesive agent contains a light absorbing material.