JPH06141133A - Manufacture of image forming device - Google Patents

Abstract

PURPOSE:To manufacture a image forming device in which a photosensing body in accurately irradiated with the light emited from a light emitting diode to form an image onto the photosensing body with high picture quality or external picture information is accurately formed on a solid-state image pickup element array via a lens array thereby allowing the solid-state image pickup element array to produce an accurate electric signal corresponding to the external picture information. CONSTITUTION:This image forming device is constituted as that a circuit board with a picture element array mounted thereon and a long lens array 3 are fixed at a prescribed interval in a housing 4, a tentative adhesive injection hole (a) is provided in the housing 4 and a rapid curing adhesive is injected to the tentative adhesive injection hole (a) to fix tentatively the lens array 3 to the housing 4. Then the housing 4 and the lens array 3 are molten and integrated by the ultrasonic wave melting method to fix the lens array 3 to the housing 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an image device used for an image forming device such as an optical printer head or an image reading device such as an image sensor, and more particularly to a long lens array on a housing. Regarding the fixing method.

[0002]

2. Description of the Related Art A conventional image forming apparatus, for example, an image forming apparatus used in an image forming apparatus such as an optical printer head, has a plurality of light emitting diode arrays formed of a plurality of light emitting diodes linearly arranged on an electrically insulating substrate. It is composed of a light-emitting element mounting substrate mounted in an array, a lens array in which a large number of rod-shaped self-focusing lenses are linearly arranged in two rows in a frame-like casing, and a housing made of polycarbonate resin, etc. Bond the element mounting substrate and the lens array with an epoxy resin adhesive so that each LED of the LED array is located on the optical axis of each self-focusing lens of the lens array with a certain distance between them. It is made by fixing.

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

[0004]

However, in this conventional image device, the long lens array is fixed to the housing by adhering the lens array to the housing with an adhesive made of epoxy resin. The curing rate of the adhesive made of the epoxy resin is extremely slow because heat of high temperature cannot be applied in consideration of thermal deformation of the resin constituting the housing. Therefore, when fixing the lens array to the housing, the fixed position of the lens array is likely to be displaced, and when the fixed position of the lens array is displaced, the optical axis of each self-focusing lens forming the lens array is moved from the predetermined position of the light emitting diode. Displacement, it was impossible to satisfactorily irradiate the photoconductor with the light emitted from the light emitting diode through the self-focusing lens, and there was a drawback that a clear latent image could not be formed accurately on the photoconductor. .

Further, the fixing of the elongated lens array to the housing is performed by adhering one whole side surface of the frame-shaped casing of the lens array to the housing with an adhesive, and The frame-shaped casing is usually made of ABS resin or FRP, and the housing is made of polycarbonate resin in consideration of flatness, strength, price, etc., and the thermal expansion coefficients of both are 0.9 to 6 respectively.
× 10 ^-5 /℃,1.9 × 10 ^-5 / if ℃ greatly from such fact that different the imaging device was used incorporated in an image forming apparatus, when heat is applied externally to the housing and the lens array A large thermal stress is generated in the bonded part of the two, causing the lens array to bend about 400 μm, and as a result,
Misalignment occurs between the optical axis of each self-focusing lens and the position of the light emitting diode, and it is impossible to radiate the light emitted by the light emitting diode onto the photoconductor satisfactorily through the self-focusing lens, which makes the photoconductor clear. However, it also has a drawback that an accurate latent image cannot be formed.

In the above-mentioned conventional example, an image device used in an image forming apparatus such as an optical printer head has been described as an example, but it is used in an image reading apparatus such as an image sensor using a solid-state image sensor array. Also in the image device, the mass productivity and workability are poor due to the same cause, and the image formation of the external image information on the solid-state image sensor array becomes non-uniform, so that the solid-state image sensor array receives an accurate electric signal corresponding to the image information. It has a drawback that it is impossible to generate.

[0007]

SUMMARY OF THE INVENTION The present invention has been conceived in view of the above-mentioned drawbacks, and an object thereof is to accurately irradiate a photoconductor with light emitted from a light emitting diode through a lens array to form an image with high image quality on the photoconductor. Or an image device capable of accurately forming an external image information on a solid-state image sensor array through a lens array and generating an accurate electric signal corresponding to the external image information on the solid-state image sensor array. It is to provide a manufacturing method.

[0008]

SUMMARY OF THE INVENTION The present invention is an image device in which a substrate on which an image element array is mounted and a long lens array are fixed at a predetermined interval in a housing. The fixing of the array to the housing is characterized by the following steps (1) to (3). (1) A step of forming a temporary adhesive injection hole in a region of the housing where the long lens array is fixed, (2) A lens array is brought into contact with the housing in which the temporary adhesive injection hole is formed, and the temporary adhesion of the housing is performed. A step of temporarily injecting a quick-drying adhesive material from the material injection hole and temporarily fixing the lens array to the housing,
(3) Step of fixing the lens array to the housing by ultrasonic welding

[0009]

According to the imaging apparatus of the present invention, since the long lens array is temporarily fixed to the housing with the quick-drying adhesive material, the lens array can be accurately fixed at a predetermined position on the housing, and the long lens array can be fixed. Since the long lens array is fixed to the housing by the ultrasonic welding method, the long lens array can be extremely firmly fixed to the housing, and the long lens array can be fixed to the housing long. If the center of the cylindrical lens array in the lengthwise direction is set, even if heat is applied to the elongated lens array and the housing from the outside, no large thermal stress is generated between the two and the lens array is curved. There is nothing to do.
Therefore, when this image device is used in an image forming device such as an optical printer head, the optical axis of each self-focusing lens of the lens array can be always located at the position of the light emitting diode, and the light emitted from the light emitting diode is directed to the photoconductor. It is possible to satisfactorily irradiate, and it is possible to form a clear and accurate latent image on the photoconductor.

When this image device is used for an image reading device such as an image sensor, since the lens array has no curvature, external image information can be accurately formed on the solid-state image pickup element array through the lens array. It is possible to generate an accurate electric signal corresponding to the external image information in the solid-state image sensor array.

[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 forming apparatus of the present invention is used in an optical printer head as an image forming apparatus. 1 is a substrate, 2 is a light emitting diode array, 3 is a lens array, and 4 is a housing. is there.

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

The substrate 1 functions as a supporting member for supporting the light emitting diode array 2. For example, when the substrate 1 is made of a sintered aluminum oxide ceramic, alumina (Al ₂ O ₃ ) or silica (SiO ₂ ) is used. ₂ ), calcia (CaO), magnesia (MgO), etc.A suitable organic solvent is added to the raw material powder, and a solvent is added and mixed to form a sludge, and the conventionally known doctor blade method or calendar roll method is adopted. 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 array 2 mounted on the substrate 1 is composed of a plurality of light emitting diodes 2a, and the light emitting diodes 2a individually and selectively emit light in response to an external electric signal and emit light. A latent image for forming an image is formed on the photoconductor 5 by irradiating the surface of the photoconductor 5 with.

The light emitting diode 2a is a GaAsP type, Ga
P-based light-emitting diodes are used.For example, in the case of GaAsP-based light-emitting diodes, the GaAs substrate is first heated to a high temperature in a furnace and AsH ₃ (arsine), PH ₃ (phosphine), Ga (gallium) are used. ) Is brought into contact with the substrate to grow an n-type semiconductor GaAsP (gallium-arsenic-phosphorus) single crystal on the substrate surface, and then a Si ₃ N ₄ (silicon nitride) windowed film is formed on the GaAsP single crystal surface. It is attached and Zn (
It is formed by exposing a (zinc) gas to diffuse Zn into a part of the GaAsP single crystal of the n-type semiconductor to form a p-type semiconductor and having a pn junction.

In the case of the B4 optical printer head, 2048 (8 per 1 mm) light emitting diodes 2a are linearly arranged. Specifically, 64 light emitting diodes are used as one unit. By arraying 32 arrays 2 in a straight line, 2048 light emitting diodes 2a are arrayed on the substrate 1.

Further, the light emitting diode 2a is provided with an elongated lens array 3 at a predetermined interval above the light emitting diode 2a, and the lens array 3 irradiates the surface of the photoreceptor 5 with the light emitted from each light emitting diode 2a. To act.

The elongated lens array 3 has a structure in which a large number of rod-shaped self-focusing lenses 8 made of glass, synthetic resin or the like are linearly arranged in two rows in a frame-shaped casing 7 for molding. A rod-shaped self-focusing lens 8 is sandwiched by a resin plate made of ABS resin etc. in the mold to be arranged and housed in two rows and silicone resin is dropped, and the resin is cured, and each self-focusing lens 8 is bonded with silicone resin. And frame-shaped casing 7
Is manufactured by forming.

The substrate 1 on which the light emitting diode array 2 is mounted and the lens array 3 also have a predetermined distance between them, and the optical axes of the self-focusing lenses 8 of the lens array 3 are the light emitting diodes of the light emitting diode array 2. It is fixed to the housing 4 made of polycarbonate resin so that it is on the upper side 2a.

The housing 4 to which the lens array 3 and the like are fixed is made of acrylonitrile butadiene styrene resin (ABS
Resin), polyphenylene sulfide (PPS resin), and polycarbonate resin, which are formed into a predetermined shape by adopting a conventionally known resin molding method.

The substrate 1 and the lens array 3 are fixed to the housing 4 by adhering the substrate 1 on which the light emitting diode array 2 is mounted inside the lower part of the housing 4 with an adhesive 5a, and also to the upper part of the lens array. Each is performed by melting and integrating 3 by an ultrasonic welding method.

To fix the lens array 3 to the housing 4, concretely, as shown in FIG. 2, first, a temporary adhesive injection hole a is formed at a position in a region of the housing 4 where the long lens array 3 is fixed. To form. The temporary adhesive injection hole a is formed in a predetermined position of the housing 4 by adopting a well-known hole forming method for the housing 4.

Next, one side of the lens array 3 is brought into contact with the housing 4 in which the temporary adhesive material injection hole a is formed, and the quick-drying adhesive material 5b is injected from the temporary adhesive material injection hole a provided in the housing 4. Temporarily attach the lens array 3 to the housing 4.

The fast-drying adhesive material 5b is made of, for example, a cyanoacrylate adhesive material, and the adhesive material 5c cures in a short time of about 3 to 6 seconds. Therefore, the lens array 3 is accurately placed on the housing 4 at a predetermined position. The lens array 3 and the housing 4 will not be misaligned.

Then, the housing 4 to which the lens array 3 is temporarily fixed is inspected for the focus accuracy of the lens array 3, and then the lens array 3 and the housing 4 are fused and integrated by an ultrasonic welding method. This completes the fixing of the lens array 3 to the housing 4. in this case,
Since the lens array 3 and the housing 4 are fused and integrated by the ultrasonic welding method, the housing 4 of the lens array 3
It becomes extremely strong in fixing.

Further, the lens array 3 to the housing 4
If the fixing by the ultrasonic welding method is performed only at the central portion A in the longitudinal direction of the elongated lens array 3, heat is applied to the housing 4 and the lens array 3 from the outside, and the thermal expansion coefficient of the both is increased. Even if the thermal stress due to the difference occurs, the thermal stress becomes extremely small because the fixing of the lens array 3 to the housing 4 is a narrow area of the central portion A of the lens array 3, and the thermal stress causes the lens array
Housing 3 with no major bends in 3
The optical axis of each self-focusing lens 8 can be always positioned on each light emitting diode 2a of the light emitting diode array 2, and the light emitted from the light emitting diode 2a is exposed through the lens array 3 to the lens array 3 fixed to the lens array 3. Body 5
It is possible to illuminate accurately and clearly. Therefore, it is preferable to fix the lens array 3 to the housing 4 by the ultrasonic welding method only at the central portion A in the longitudinal direction of the elongated lens array 3.

Thus, in the image device manufactured by the manufacturing method of the present invention, a plurality of light emitting diodes 2a linearly arranged on the substrate 1 are caused to individually and selectively emit light in response to an external electric signal, and the light is emitted. By irradiating the photoconductor 5 with the generated light through the lens array 3, it functions as an image forming apparatus.

The present invention is not limited to the above embodiments, but various modifications can be made without departing from the scope of the present invention. For example, the lens array 3 has a center in the longitudinal direction. The part A was fixed to the housing 4 by the ultrasonic welding method.
If fixed to the housing 4 with a soft adhesive of Kgf / cm ² or more, the lens array 3 can be firmly fixed to the housing 4 while keeping the thermal stress generated between the lens array 3 and the housing 4 small. You can Therefore, when fixing the lens array 3 to the housing 4,
The central part A of 3 is ultrasonically welded, and both ends have an elastic modulus of 35 Kgf /
It is preferable to fix with a soft adhesive having a cm ² or more, specifically, an adhesive made of silicone rubber or epoxy mixed with rubber.

In the above-mentioned embodiment, the case where it is used in an image forming apparatus such as an optical printer head has been described as an example. However, the light emitting diode array is replaced with a solid-state image sensor array, and it is also used in an image reading apparatus such as an image sensor. It can be used.

[0030]

According to the manufacturing method of the present invention, since the long lens array is temporarily temporarily fixed to the housing with the quick-drying adhesive material, the lens array can be accurately bonded and fixed to a predetermined position of the housing. Since the long lens array is fixed to the housing by the ultrasonic welding method, the long lens array can be fixed to the housing extremely firmly.

Particularly, when the lens array is fixed to the housing by the ultrasonic welding method only at the central portion in the length direction of the elongated lens array, heat is applied from the outside to the housing and the lens array, and the two are interposed between them. Even if a thermal stress due to a difference in the thermal expansion coefficient of the lens is generated, the thermal stress can be made extremely small, and as a result, the lens array is not greatly curved due to the thermal stress, and the housing does not have a large curvature. The fixed lens array can always position the optical axis of each self-focusing lens on each light-emitting diode of the light-emitting diode array, and the light emitted from the light-emitting diode can be accurately and clearly reflected on the photoconductor through the lens array. Can be irradiated.

When this image device is used in an image reading device such as an image sensor, external image information can be accurately formed on the solid-state image pickup element array through the lens array, and the solid-state image pickup element array can be formed. It is also possible to generate an accurate electric signal corresponding to the external image information.

[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 cross-sectional view for explaining adhesive fixing of a lens array and a housing of the image forming apparatus shown in FIG.

[Explanation of symbols]

 1 ... substrate 2 ... light emitting diode array 2a ... light emitting diode 3 ... lens array 4 ... housing 5a・ ・ ・ Adhesive 5b ・ ・ Quick-drying adhesive a ・ ・ ・ ・ Temporary adhesive injection hole A ・ ・ ・ ・ ・ ・ Center of lens array

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G02B 3/00 A 8106-2K 7/02 A H01L 33/00 N 7376-4M H04N 1/028 Z 8721-5C

Claims (1)

[Claims] 1. An image device in which a substrate on which an image element array is mounted and a long lens array are fixed at a predetermined interval in a housing, wherein the long lens array is fixed to a housing. An image device manufacturing method comprising the following steps (1) to (3). (1) A step of forming a temporary adhesive injection hole in a region of the housing where the long lens array is fixed, (2) A lens array is brought into contact with the housing in which the temporary adhesive injection hole is formed, and the temporary adhesion of the housing is performed. A step of temporarily injecting a quick-drying adhesive from the material injection hole to temporarily fix the lens array to the housing, (3) a step of fixing the lens array to the housing by ultrasonic welding.