JP2766111B2 - Method of manufacturing imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an image forming apparatus such as an optical printer head or an image reading apparatus such as an image sensor, and more particularly, to a method for mounting an image element array on a housing. The present invention relates to a method for fixing a long substrate that has been made.

[0002]

2. Description of the Related Art A conventional image device, for example, an image device used for an image forming apparatus such as an optical printer head, comprises a light emitting diode array comprising a plurality of light emitting diodes on an electrically insulating substrate. It is composed of a long light emitting element mounting substrate mounted and mounted, a lens array in which a number of bar-shaped self-focusing lenses are linearly arranged in two rows in a frame-shaped casing, and a housing made of polycarbonate resin or the like. Adhesion made of epoxy resin so that the light emitting element mounting substrate and the lens array are separated from each other in the housing by a predetermined distance, and each light emitting diode of the light emitting diode array is positioned on the optical axis of each self-focusing lens of the lens array. It is manufactured by bonding and fixing through materials.

In such an image apparatus, each light emitting diode of a light emitting diode array is selectively and individually made to emit light in accordance with an external electric signal, and the light emitted by each light emitting diode is transmitted through a lens array to an external photosensitive member surface. The image forming apparatus functions as an image forming apparatus by forming a latent image on the photosensitive member.

[0004]

However, in this conventional image apparatus, a long light emitting element mounting board, which is formed by mounting a plurality of light emitting diode arrays in a linear array, is fixed to the housing at the bottom of the board. The entire surface is bonded to the housing with an adhesive made of epoxy resin, and the adhesive made of epoxy resin applies heat at a high temperature in consideration of the thermal deformation of the resin forming the housing. Very slow because you can not.
Therefore, when the long light emitting element mounting board is fixed to the housing, it is easy for the fixing position of the light emitting element mounting board to be misaligned. The optical axis of each of the self-focusing lenses that make up the lens array is misaligned, making it impossible to irradiate the light emitted from the light emitting diode to the photoconductor through the self-focusing lens in a favorable manner. There was a disadvantage that an image could not be formed.

The fixing of the long light emitting element mounting substrate to the housing is performed by bonding the entire bottom surface of the substrate to the housing via an adhesive material. , Glass and alumina ceramics, and the housing is made of polycarbonate resin in consideration of flatness, strength, price, etc. The thermal expansion coefficients of both are 0.6 to 0.8 × 10 ^{-5 /} ° C, 1.9 ×
When this image device is used by incorporating it into an image forming apparatus due to a large difference of 10 ^-5 / ° C, etc., when heat is applied to the housing and the light emitting element mounting substrate from the outside, a large heat Stress is generated and the light emitting element mounting substrate is
Curved by about 250 μm, resulting in a gap between each light-emitting diode and the optical axis of the self-focusing lens, making it impossible to irradiate the light emitted from the light-emitting diode to the photoconductor through the self-focusing lens. As a result, a clear and accurate latent image cannot be formed on the photosensitive member.

In the above conventional example, an image apparatus used for an image forming apparatus such as an optical printer head has been described as an example, but it is used for an image reading apparatus such as an image sensor using a solid-state image sensor array. In the same type of imaging device, mass productivity and workability are poor due to the same cause, and the image formation of the external image information on the solid-state imaging device array becomes non-uniform. Has the drawback that it is impossible to generate

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to accurately irradiate light emitted from a light emitting diode to a photoreceptor through a lens array to form an image with high image quality on the photoreceptor. Or an image device capable of accurately forming external image information on a solid-state image sensor array via 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 relates to an image apparatus comprising a lens substrate and an elongated substrate having an image element array mounted in a housing and fixed at a predetermined interval.
The fixing of the long substrate on which the image element array is mounted to the housing includes the following steps (1) to (3).

(1) An adhesive injection hole is formed at a position where the central portion in the longitudinal direction of the substrate is fixed in a region where the elongated substrate of the housing is fixed, and a temporary adhesive injection hole is formed at another position. (2) a long substrate is brought into contact with the housing in which the adhesive injection hole and the temporary adhesive injection hole are formed, and a quick-drying adhesive is injected from the temporary adhesive injection hole of the housing to lengthen the housing. (3) a step of injecting an adhesive through an adhesive injection hole of the housing to which the long substrate is temporarily fixed, and fixing the long substrate to the housing;

[0010]

According to the image device of the present invention, since the long substrate on which the image element array is mounted on the housing is temporarily fixed with a quick-drying adhesive, the image element array is accurately mounted on a predetermined position of the housing. The long substrate can be fixed, and the long substrate on which the image element array is mounted is fixed to the housing at the center in the longitudinal direction of the substrate. Even if heat is applied, no large thermal stress occurs between them, and as a result, the long substrate on which the image element array is mounted does not curve. Therefore, when this image apparatus is used in an image forming apparatus such as an optical printer head, the position of the light emitting diode can always be set to the position of the optical axis of each self-focusing lens of the lens array, and the light emitted from the light emitting diode can be exposed. It is possible to irradiate the body satisfactorily, and a clear and accurate latent image can be formed on the photoconductor.

When this image device is used in an image reading device such as an image sensor, since the lens array has no curvature, it is possible to accurately form external image information on the solid-state image sensor array via the lens array. This makes it possible to generate an accurate electric signal corresponding to the external image information in the solid-state imaging device array.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIGS. 1 and 2 show an embodiment in which the image apparatus of the present invention is applied to an optical printer head as an image forming apparatus, 1 is a long substrate, 2 is a light emitting diode array,
Denotes a lens array, and 4 denotes a housing.

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

The substrate 1 serves as a support member for supporting the light emitting diode array 2. For example, when the substrate 1 is made of a ceramic of an aluminum oxide sintered body, alumina (Al ₂ O ₃ ), silica (SiO ₂ ) ₂ ), an appropriate organic solvent and a solvent are added to raw material powders such as calcia (CaO) and magnesia (MgO) to form a slurry by mixing and using a conventionally known doctor blade method or calender roll method. Thus, a ceramic green sheet (ceramic green sheet) is obtained. Thereafter, the ceramic green sheet is punched into a predetermined shape and fired at a high temperature (about 1600 ° C.).

The light-emitting diode array 2 mounted on the substrate 1 is composed of a plurality of light-emitting diodes 2a. The light-emitting diodes 2a selectively and individually emit light in response to an external electric signal. Is irradiated onto the surface of the photoconductor 5 to form a latent image for forming an image on the photoconductor 5.

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

In the case of a B4 optical printer head, the light emitting diodes 2a are linearly arranged at 2048 pieces (8 pieces per 1 mm), and specifically, the light emitting diodes having 64 light emitting diodes as one unit. By arranging 32 arrays 2 in a straight line, 2048 light emitting diodes 2a are arranged on the long substrate 1.

Further, the light emitting diode 2a is provided with a long lens array 3 at a predetermined interval above the light emitting diode 2a, and the lens array 3 irradiates light emitted from each light emitting diode 2a to the surface of the photosensitive member 5. Works.

The long 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 arranged in a line in a line in a frame-shaped casing 7. The rod-shaped self-focusing lenses 8 are sandwiched between ABS resin or FRP plates in a mold, and are arranged and housed in two rows. Silicon resin is dropped, the resin is cured, and each of the self-focusing lenses 8 is bonded with the silicon resin. It is manufactured by forming a frame-like casing 7.

The elongated substrate 1 on which the light emitting diode array 2 is mounted and the lens array 3 are also provided with a predetermined distance between them, and the optical axis of each self-focusing lens 8 of the lens array 3 is Are fixed to a housing 4 made of polycarbonate resin so as to be on each light emitting diode 2a.

The substrate 1 and the lens array 3 are fixed to the housing 4 by mounting an elongate substrate 1 on which a light-emitting diode array 2 is mounted on the lower inner side of the housing 4 and a lens array 3 on the upper side. This is performed by bonding through the adhesives 5a and 5b.

The fixing of the long substrate 1 to the housing 4 via the adhesive 5a is specifically performed in a region where the long substrate 1 of the housing 4 is fixed. Adhesive injection hole a at the position where the center in the vertical direction is fixed,
A temporary adhesive injection hole b is formed at another position. The adhesive injection hole a and the temporary adhesive injection hole b are formed at predetermined positions in the housing 4 by employing a conventionally known drilling method.

Next, the bottom surface of the elongated substrate 1 is brought into contact with the housing 4 in which the adhesive injection hole a and the temporary adhesive injection hole b are formed. Of the long substrate 1 into the housing 4
Temporarily.

The quick-drying adhesive 5c is made of, for example, a cyanoacrylate adhesive, and the adhesive 5c cures in a short time of about 3 to 6 seconds. Even if the long substrate 1 is fixed to the housing 4 to be described later with an adhesive 5a made of an epoxy resin, which takes a long time to cure, the long substrate 1 It is fixed in position and does not generate any displacement.

Then, an adhesive 5a made of epoxy resin or the like is injected from the adhesive injection hole a into the housing 4 to which the elongated substrate 1 is temporarily fixed, and the adhesive 5a is hardened to form the elongated substrate. The adhesive fixation between the substrate 1 and the housing 4 is completed.

The adhesive injection hole a provided in the housing 4 is formed at a position located at the center of the long substrate 1 in the longitudinal direction.
Adhesion and fixation are performed at the center of the long substrate 1 in the length direction, and both ends are free. Therefore, even if heat is applied to the housing 4 and the elongated substrate 1 from the outside, and a thermal stress is generated between the two due to a difference in thermal expansion coefficient between the two, the thermal stress is applied to the housing 4 of the elongated substrate 1. Is very small due to the small area at the center of the long substrate 1, and as a result, the stress does not cause a large curvature in the long substrate 1. Accordingly, the position of the light emitting diode 2a mounted on the upper surface of the elongated substrate 1 fixed to the housing 3 is always on the optical axis of each self-focusing lens 8 of the lens array 3, and the light emitted from the light emitting diode 2a is emitted. Lens array 3
It is possible to accurately and clearly irradiate the photoreceptor 5 via the.

Thus, the image device manufactured by the manufacturing method of the present invention selectively emits a plurality of light emitting diodes 2a linearly arranged on the substrate 1 in response to an external electric signal. By irradiating the photoreceptor 5 with the light thus emitted via the lens array 3, the device functions as an image forming apparatus.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Only the central part of the long substrate 1 is bonded and fixed to the housing 4 with an adhesive 5a, but if both ends of the long substrate 1 are further fixed to the housing 4 with a soft adhesive having an elastic modulus of 35 kgf / cm ² or more. In addition, the elongated substrate 1 can be firmly fixed to the housing 4 while keeping the thermal stress generated between the elongated substrate 1 and the housing 4 small. Therefore, when fixing the long substrate 1 to the housing 4, the central portion of the long substrate 1 is an epoxy or acrylic adhesive material 5 a,
It is preferable to fix both ends with a soft adhesive having an elastic modulus of 35 kgf / cm ² or more, specifically, an adhesive made of silicone rubber or epoxy mixed with rubber.

In the above embodiment, the case where the present invention is used for an image forming apparatus such as an optical printer head has been described as an example. However, the light emitting diode array is changed to a solid-state image sensor array and the image reading apparatus such as an image sensor is also used. Can be used.

[0030]

According to the manufacturing method of the present invention, the long substrate on which the image element array is mounted on the housing is temporarily fixed in advance with a quick-drying adhesive, so that the long substrate is fixed at a predetermined position of the housing. It is possible to adhere accurately and fix the long substrate to the housing at the center in the length direction of the long substrate, so that heat is applied to the housing and the long substrate from the outside. Also, no large thermal stress is generated between them, and the long substrate does not bend. Therefore, when the image device manufactured by this manufacturing method is used for an image forming apparatus such as an optical printer head, the position of the light emitting diode mounted on the upper surface of the substrate is always set on the optical axis of each self-focusing lens of the lens array. It is possible to irradiate the light emitted from the light emitting diode to the photoconductor satisfactorily, and a clear and accurate latent image can be formed on the photoconductor.

When this image device is used in an image reading device such as an image sensor, it becomes possible to accurately form external image information on a solid-state image sensor array via a lens array. An accurate electric signal corresponding to the external image information can be generated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment in which an image forming apparatus according to 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 between a substrate on which a light emitting diode is mounted and a housing of the image forming apparatus shown in FIG.

[Explanation of symbols]

 1 ... board 2 ... light emitting diode array 2a ... light emitting diode 3 ... lens array 4 ... housing 5a 5b: adhesive material 5c: quick-drying adhesive material a: adhesive material injection hole b: temporary adhesive material injection hole

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 1/028 (56) References JP-A-64-42247 (JP, A) JP-A-3-118169 (JP, A) JP-A-62-211972 (JP, A) JP-A-3-118169 (JP, A) JP-A-59-225970 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2 / 44 B41J 2/45 B41J 2/455 G02B 7/00 G02B 27/00 H04N 1/028

Claims (1)

(57) [Claims] 1. An image apparatus comprising: a long substrate having an image element array mounted in a housing; and a lens array fixed at a predetermined interval, wherein the long substrate has the image element array mounted thereon. Fixing to the housing comprises the following steps (1) to (3). (1) forming an adhesive injection hole at a position where the central portion in the longitudinal direction of the substrate is fixed in a region where the elongated substrate of the housing is fixed, and forming a temporary adhesive injection hole at another position; (2)
The long substrate is brought into contact with the housing in which the adhesive injection hole and the temporary adhesive injection hole are formed, and a quick-drying adhesive is injected from the temporary adhesive injection hole of the housing to temporarily fix the long substrate to the housing. (3) a step of injecting an adhesive through an adhesive injection hole of the housing to which the elongated substrate is temporarily fixed, and fixing the elongated substrate to the housing.