JP2892266B2 - 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 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 apparatus, for example, an image apparatus used for an image forming apparatus such as an optical printer head, is usually a lens made of a resin such as polycarbonate in which a plurality of lenses are linearly supported at predetermined intervals. A plate and a base plate made of a resin such as polycarbonate in which a number of light emitting diode element arrays are linearly arranged and mounted on a pair of supports so that each lens and each light emitting diode element array correspond one to one. The light emitting diode elements of each light emitting diode element array are selectively and individually lit according to an external electric signal, and the light emitted by the light emitting diode elements is transmitted to a lens. An image is formed on an external photoconductor via the photoconductor and a latent image is formed on the photoconductor, thereby functioning as an image forming apparatus.

A light emitting diode element array linearly arranged and mounted on the base plate generally includes 64 light emitting diode elements linearly arranged therein, and is used in a B4 size image forming apparatus. When used, the light emitting diode element array is mounted on the base plate such that 32 light emitting diode elements correspond to the respective lenses one by one.

Each of the light emitting diode element arrays has a common electrode on the lower surface thereof. The common electrode is formed on a common electrode wiring previously formed on the upper surface of the base plate, for example, epoxy resin or silver powder. The common electrode is mounted on the base plate while electrically connecting the common electrode to the common electrode wiring by bonding via a conductive resin adhesive to which is added.

Further, each light-emitting diode element array mounted on the upper surface of the base plate has its individual electrode electrically connected to an individual electrode wiring formed on the upper surface of the base plate via a bonding wire. By connecting the common electrode wiring and the individual electrode wiring on the upper surface of the base plate to an external electric circuit, each light emitting diode element of the light emitting diode element array is electrically connected to the external electric circuit.

However, in this conventional image device, the individual electrodes provided on the light emitting diode element array are connected to the individual electrode wirings of the base plate via bonding wires, and the individual electrodes of the light emitting diode element array are several thousand. Since it is extremely large, it takes a long time to electrically connect the individual electrodes of the light emitting diode element array to the individual electrode wirings of the base plate, and the workability of the image device is poor, and the image device as a product is expensive. I had.

In the above-described embodiment, an image apparatus used for an image forming apparatus such as an optical printer head has been described as an example. However, an image sensor using a solid-state image sensor array (CCD element array) or the like has been described. An image device used for an image reading device or the like has the same disadvantage.

In order to solve the above-mentioned drawbacks, the applicant of the present application firstly changed the image element array to a first element having a common electrode wiring.
A light emitting / receiving unit of each image element array is arranged between the substrate and the second substrate having the individual electrode wiring and the window so as to face the window, and a common electrode of each image element array is provided on the first substrate. An image device was proposed in which the individual electrodes were connected to the individual electrode wires of the second substrate by flip-chip connection while being connected to the common electrode wires.

According to such an image apparatus, since the individual electrodes provided on the image element array are connected to the individual electrode wirings of the second substrate by flip-chip connection, even if there are thousands of individual electrodes, all of them are the second electrodes. The individual electrode wirings of the substrate are electrically connected at once and firmly, and as a result, the productivity and reliability of the image device become extremely excellent.

In this image apparatus, a second substrate uses a printed board in which a copper foil is attached to a glass epoxy board in a predetermined pattern, and the printed board is opaque. A window having a width of 100 μm or less is formed in a region of the second substrate facing the light emitting / receiving portion of the image element array to form a light passage therebetween.

In this image apparatus, the distance between the light emitting / receiving section of the image element array and the individual electrode is generally about 100 μm, and the image element is arranged with the light emitting / receiving section of the image element array facing the window of the second substrate. One end of the individual electrode wiring of the second substrate is formed within a range of 50 μm or less from the edge of the window in order to flip-chip connect the individual electrodes of the array to the individual electrode wiring of the second substrate.

[0012]

However, in this image apparatus, a hole having a width of about 100 μm must be formed in the second substrate in order to form a light path between the image element array and the lens. Since the second substrate is formed of a printed circuit board having low rigidity and easy to generate deformation such as bending and the like, and a boring tool has a wobble, a small hole having a width of about 100 μm is formed in the printed circuit board. In order to form the image device, an extremely advanced technique is required. As a result, the productivity and the yield of the image device are greatly reduced, and a disadvantage that the image device as a product is extremely expensive is induced.

Further, the width of the second substrate made of a printed circuit board is
Even if a hole with a size of about 100 μm is formed, the hole has a low rigidity and is easily deformed by bending or the like. When the width of the hole is reduced, a light path is not formed between the image element array and the lens, and the light emitted from the light emitting diode element is irradiated on the photosensitive member through the lens to form a latent image on the photosensitive member. It is impossible to irradiate the solid-state imaging device array with external image information through a lens, and to generate an electric signal corresponding to the external image information to the solid-state imaging device array. The disadvantage is that the individual electrodes of the image element array cannot be flip-chip connected.

[0014]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to accurately irradiate light emitted from a light-emitting diode element onto a photoreceptor surface through a lens, and to provide a latent image having high image quality to the photoreceptor. Production that can form an image or accurately form external image information on a solid-state image sensor array via a lens and generate an accurate electric signal corresponding to the external image information on the solid-state image sensor array An object of the present invention is to provide a good and inexpensive image device.

[0015]

According to the present invention, there is provided an image apparatus in which a lens member comprising a plurality of lenses and an image element member having a large number of image element arrays are fixedly provided side by side. A plurality of image element arrays are arranged between the first substrate having the common electrode wiring and the second substrate having the individual electrode wiring and the window, such that the light emitting / receiving portion of the image element array faces the window. And the common electrodes of each image element array are connected to the common electrode wiring of the first substrate, and the individual electrodes are connected to the individual electrode wiring of the second substrate by flip-chip connection. The substrate is formed by providing a gap serving as a window between them, and bonding the substrates with a transparent adhesive filled in the gap.

[0016]

According to the image device of the present invention, since the individual electrodes of the image element array are electrically connected to the individual electrode wiring provided on the second substrate by flip-chip connection, there are thousands of individual electrodes of each image element array. However, all of them can be electrically connected to the individual electrode wirings of the second substrate at once and firmly, and as a result, the productivity and reliability of the image device become extremely excellent.

According to the image apparatus of the present invention, the window portion of the second substrate is provided with a predetermined gap (for example, 100 μm) between the two substrates.
m) is formed by arranging the windows in parallel, so that the windows can be formed with extremely high precision and easily, which also makes the productivity and yield of the image apparatus extremely excellent. Become.

Further, according to the image apparatus of the present invention, since the transparent adhesive is filled in the gap between the two substrates serving as the windows of the second substrate, the width of the gap (window) is always constant. As a result, the individual electrodes of the image element array can be accurately flip-chip connected to the individual electrode wirings provided on the second substrate, and when this image device is used in an image forming apparatus such as an optical printer head, the light emission occurs. The light emitted from the diode element can be accurately irradiated on the surface of the photoreceptor via a lens to form a latent image with high image quality on the photoreceptor. The image information can be accurately formed on the solid-state imaging device array via the lens, and the solid-state imaging device array can generate an accurate electric signal corresponding to the external image information.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIGS. 1 to 4 show an embodiment in which the image apparatus of the present invention is applied to an optical printer head as an image forming apparatus, wherein 1 is an image element member, 5 is a lens member, and 8 is a support.

The image element member 1 comprises a first substrate 2, a plurality of light emitting diode element arrays 3, and a second substrate 4 having a window 4a in the center.

The first substrate 2 of the image element member 1 functions as a supporting member for supporting the light emitting diode element array 3, and a plurality of light emitting diode element arrays 3
Are mounted in a linear array.

The first substrate 2 is made of an aluminum oxide sintered body, crystallized glass, quartz or the like. For example, when the first substrate 2 is made of an aluminum oxide sintered body, alumina, silica,
Organic solvent suitable for raw material powder such as calcia, magnesia,
A solvent is added and mixed to form a slurry, and a ceramic green sheet (ceramic green sheet) is obtained by adopting a conventionally known doctor blade method, calendar roll method, or the like. And high temperature (about 15
(00 ° C.).

The light emitting diode element array 3 mounted on the first substrate 2 has a plurality of light emitting diode elements 3a.
The light emitting diode element 3a selectively emits light individually in response to an external electric signal, and irradiates the emitted light to the surface of the photoconductor P to form a latent image for forming an image on the photoconductor P. Form.

The light emitting diode element 3a is of GaAsP type, Ga
P-based light-emitting diodes are used.For example, in the case of GaAsP-based light-emitting diodes, first, a GaAs substrate is heated to a high temperature in a furnace, and AsH ₃ (arsine), PH ₃ (phosphine), and Ga (gallium) are used. ) Is brought into contact with a gas containing an appropriate amount of GaAsP (gallium-arsenide-phosphorus) single crystal on the substrate surface, and then Si ₃ O 4 is grown on the GaAsP single crystal surface.
An N ₄ (silicon nitride) film with a window is deposited, and the window is exposed to a gas of Zn (zinc).
Zn is diffused into a part of the single crystal to form a p-type semiconductor, and pn
It is formed by having a bond.

In the case of an optical printer head of B4 size, the number of the light emitting diode elements 3a is 2048 (8 per 1 mm).
Are linearly arranged, specifically, a light emitting diode element array in which 64 light emitting diode elements 3a are one unit.
By arranging 32 pieces of 3 in a straight line, 2048 light emitting diode elements 3a are arranged on the first substrate 2.

As shown in FIG. 3, the light emitting diode element array 3 is mounted on the first substrate 2 by forming a common electrode wiring 2a of a predetermined pattern on the upper surface of the first substrate 2 in advance. This is performed by bonding the common electrode 31 on the lower surface of the light emitting diode element array 3 to the common electrode wiring 2a via the solder S. In this case, the solder S is melted and solidified in a short time, and the self-alignment effect, that is, the first
Since the common electrode wiring 2a attached to the substrate 2 and the common electrode 31 of the light emitting diode element array 3 are attracted so as to face each other, the light emitting diode element array 3
It will be mounted very accurately at a predetermined position of the common electrode wiring 2a attached to the substrate 2, and as a result, when this is used as an image forming apparatus, the center of the light emitting diode element array 3 will always be described later. It is possible to irradiate the light emitted from the light emitting diode elements 3a of each light emitting diode element array 3 onto the entire surface of the photoconductor P satisfactorily, being located at the center of each lens 7.

Further, the common electrode wiring 2a formed on the first substrate 2 and the common electrode 31 of the light emitting diode element array 3
When the light emitting diode element array 3 is mounted on the first substrate 2 by soldering, the solder S is previously deposited on the surface of the common electrode wiring 2a deposited on the first substrate 2 by plating. And the common electrode wiring 2a attached to the first substrate 2
The light-emitting diode element array 3 is mounted so that the common electrode 31 is in contact with the upper part of the device, and the two can be joined by a simple operation of applying heat to the mounting portion. When a plurality of light emitting diode element arrays 3 are linearly mounted on the first substrate 2 using the solder S previously deposited on the surface by plating, the common electrode wiring 2a is deposited on the surface by plating. The amount of solder S is
Since the heights are uniform, each light emitting diode element array 3 is also firmly mounted on the first substrate 2 and is mounted at the same height, and each light emitting diode element array 3 mounted on the first substrate 2 and a lens 7, the light emitted from the light emitting diode elements 3a of each light emitting diode element array 3 can be uniformly and satisfactorily applied to the entire surface of the photoconductor P. Therefore, when the light emitting diode element array 3 is mounted on the first substrate 2 via the solder S, the solder is previously deposited on the surface of the common electrode wiring 2a deposited on the first substrate 2 by plating. Preferably.

The common electrode wiring 2a formed on the first substrate 2 is formed by depositing a conductive material such as aluminum or copper on the upper surface of the first substrate 2 to a predetermined thickness by vapor deposition or sputtering. At the same time, this is processed into a predetermined pattern by an etching method, and thereafter, the surface is nickel-plated or gold-plated to be formed on the upper surface of the first substrate 2.

On the upper surface of the light emitting diode element array 3 mounted on the first substrate 2, a printed circuit board using, for example, a glass epoxy substrate or the like is formed. A second substrate 4 having a window 4a having a width of about 100 μm for forming a light path and having an individual electrode wiring 4b adhered to the lower surface is fixedly joined.

The second substrate 4 is provided with each light emitting diode element 3a.
The individual electrodes 32 of each light emitting diode element 3a are electrically connected to an external electric circuit, and as shown in FIG.
Are connected in a flip-chip manner, specifically, a second substrate 4 is provided on the upper surface of each light emitting diode element array 3, and individual electrodes of each light emitting diode element 3a provided in the light emitting diode element array 3 are connected.
32 and the individual electrode wirings 4b attached to the lower surface of the second substrate 4 are placed so as to face each other with a solder bump interposed therebetween. Thereafter, the solder bump is heated and melted, and each of the light emitting diode elements 3a is melted. By soldering the individual electrode 32 and the individual electrode wiring 4b of the second substrate 4, the individual electrode 32 of each light emitting diode element 3a is electrically connected to the individual electrode wiring 4b of the second substrate 4 connected to an external electric circuit. It will be connected. In this case, although the total number of the individual electrodes 32 of each light emitting diode element 3a is as large as several thousands, all of them are electrically connected at once and firmly to the individual electrode wiring 4b adhered to the lower surface of the first substrate 4. As a result, the productivity and reliability of the image device become extremely excellent.

As shown in FIG. 4, the second substrate 4 is
The substrates 41, 41 are formed by arranging and providing a gap between them as the window 4a and bonding them with a transparent adhesive 42 filled in the gap.
Since the windows 4a are formed by arranging them in parallel so as to form a predetermined gap (for example, 100 μm) therebetween, the window 4a can be formed extremely accurately and easily. The productivity and yield of the imaging device are extremely excellent.

Further, since the gap (window 4a) formed between the two substrates 41, 41 is filled with the transparent adhesive 42, the width of the gap (window 4a) is always constant. Then, the light emitted from each light emitting diode element 3a of the light emitting diode element array 3 is accurately irradiated on the surface of the photoconductor P via the transparent adhesive 42 and the lens 7 of the window 4a, and the latent image of high image quality is formed on the photoconductor P. Can be formed, and the position of the individual electrode wiring 4b on the second substrate is always set to a predetermined position, and the individual electrode wiring 4b
The individual electrodes 32 of the light emitting diode element array 3 can be flip-chip connected accurately and reliably.

The two substrates 41 and 4 serving as the second substrate 4 are used.
1 is, for example, a printed circuit board in which a predetermined pattern of copper foil or the like serving as an individual electrode wiring 4b is adhered to a glass epoxy board, and the printed circuit board made of the glass epoxy board is, for example, an epoxy resin made into a sol in glass fiber. And then the epoxy resin is cured by heat.

The image element member 1 composed of the first substrate 2, the light emitting diode element array 3 and the second substrate 4 is provided with a lens member 5 on the upper part thereof at a predetermined distance.

The lens member 5 comprises a lens plate 6 in which a plurality of holes 6a are linearly arranged and a plurality of lenses 7. The lens 7 is brought into contact with the holes 6a provided in the lens plate 6. It is formed by bonding and fixing through an adhesive.

The lens plate 6 of the lens member 5 functions as a support member for supporting a plurality of lenses 7 at predetermined intervals on the upper surface.
The light emitted from each of the light emitting diode elements 3a is transmitted to the lens 7.

The lens plate 6 is formed of the same material as the first substrate 2 on which the light emitting diode element array 3 is mounted, such as crystallized glass or quartz. When used as an image forming apparatus, the lens plate 6 and the first
Even if heat is applied to both of the substrates 2, the lens plate 6 and the first substrate 2 thermally expand by substantially the same amount and the lens plate 6
There is no displacement between each lens 7 supported by 6 and each light emitting diode element array 3 mounted on the first substrate 2, and as a result, the light emitted from each light emitting diode element 3a Accurately on the photoconductor P surface via lens 7,
In addition, a clear image is formed, and a high-quality latent image can be formed by the photoconductor P.

Each of the lenses 7 supported on the lens plate 6 receives light emitted from each of the light emitting diode elements 3a.
A lens formed of a transparent resin such as an acrylic resin or a polycarbonate resin or a transparent inorganic material such as a glass, which has a function of irradiating the P-plane, is preferably used.

Each lens 7 is linearly bonded to the lens plate 6 at predetermined intervals by bonding a part of the outer surface of the lens 7 to the lens plate 6 via an epoxy resin-based elastic adhesive.

Further, the image element member 1 and the lens member 5
By fixing each of them to a pair of supports 8, 8, each light emitting diode element array 3 and each lens 7 are provided side by side so as to correspond one to one with a predetermined distance.

The pair of supports 8, 8 are provided with a first
And a second reference surface 8b at the bottom, and a first reference surface 8a of the support 8 has a lens plate 5
6 on the second reference surface 8b of the support 8
By fixing the substrate 2 in contact, each light emitting diode element array 3 and each lens 7 are separated from each other by a predetermined distance.
It corresponds to one-to-one. In this case, the support 8
Of the image element member 1 contacting the second reference surface 8b of the first substrate
2 is made of a highly rigid material such as an aluminum oxide sintered body which is unlikely to be deformed.
Even when external force or thermal stress is applied to the first substrate 2 when fixing the first substrate 2, the first substrate 2 does not deform such as warping or twisting. As a result, the first substrate 2 is mounted on the first substrate 2. Each of the light emitting diode element arrays 3 can always accurately face each lens 7.

Thus, according to the image apparatus of the present invention, a predetermined power is applied to each of the light emitting diode elements 3a of the image element member 1 to cause each of the light emitting diode elements 3a to selectively emit light individually. The light emitted by 3a is imaged on the external photoconductor P surface via the lens 7 of the lens member 5,
By forming a predetermined latent image on the photoconductor P, it functions as an image forming apparatus.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention. For example, the distance between the image element member 1 and the lens member 5 can be changed. And adjacent light emitting diode element array 3
If the light-shielding plate 9 is arranged between the light-emitting diodes 3, the light emitted from the light-emitting diode elements 3a of each of the light-emitting diode element arrays 3 will leak to the adjacent light-emitting diode element array 3 even if the light is completely leaked by the light-shielding plate 9. As a result, the light emitted from the light emitting diode elements 3a of each light emitting diode element array 3 is irradiated and imaged on the photoconductor P only through the corresponding lens 7 on a one-to-one basis, and is unnecessary for the photoconductor P. There is no bleeding or the like due to light irradiation, and an extremely clear latent image can be formed. Therefore, the image element member 1
Preferably, a light-shielding plate 9 is provided between the light-emitting diode element array 3 and the lens member 5 and between adjacent light-emitting diode element arrays 3.

In the above-described embodiment, a lens member 5 is used in which a plurality of lenses 7 are bonded and fixed to a lens plate 6 in which a plurality of holes 6a are linearly arranged. It may be changed to a so-called selfoc lens in which a number of self-focusing lenses are arranged.

Further, in the above-described 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 element array is changed to a solid-state image sensor array and the image reading apparatus such as an image sensor is used. Can also be used.

[0046]

According to the image device of the present invention, the individual electrodes of the image element array are electrically connected to the individual electrode wirings provided on the second substrate by flip-chip connection. Even if there are a thousand, all of them are second
The individual electrode wirings of the substrate are electrically connected at once and firmly, and as a result, the productivity and reliability of the image device become extremely excellent.

According to the image apparatus of the present invention, the window of the second substrate is provided with a predetermined gap (for example, 100 μm) between the two substrates.
m) is formed by arranging the windows in parallel, so that the windows can be formed with extremely high precision and easily, which also makes the productivity and yield of the image apparatus extremely excellent. Become.

Further, according to the image apparatus of the present invention, since the transparent adhesive is filled in the gap between the two substrates serving as the windows of the second substrate, the width of the gap (window) is always constant. As a result, the individual electrodes of the image element array can be accurately flip-chip connected to the individual electrode wirings provided on the second substrate, and when this image device is used in an image forming apparatus such as an optical printer head, the light emission occurs. The light emitted from the diode element can be accurately irradiated on the surface of the photoreceptor via a lens to form a latent image with high image quality on the photoreceptor. The image information can be accurately formed on the solid-state imaging device array via the lens, and the solid-state imaging device array can generate an accurate electric signal corresponding to the external image information.

[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 sectional view taken along line XX of FIG.

FIG. 3 is an enlarged sectional view of a main part for describing an image element member of the image device shown in FIG.

FIG. 4 is a plan view of a second substrate of the image device shown in FIG.

[Explanation of symbols]

 1 ... image element member 2 ... first substrate 2a ... common electrode wiring 3 ... light emitting diode element array 3a ... light emitting diode element 4 ... second substrate 4a ... Window 4b Individual electrode wiring 5 Lens member 6 Lens plate 7 Lens 31 Common electrode 32 Individual electrode 41 Second substrate Substrate 42: transparent adhesive S: solder

Claims (1)

(57) [Claims] 1. An image apparatus comprising: a lens member comprising a plurality of lenses; and an image element member having a large number of image element arrays. The image element member has a first electrode having a common electrode wiring. A plurality of image element arrays are arranged between the substrate and the second substrate having the individual electrode wiring and the window so that the light emitting / receiving portion of the image element array faces the window, and The common electrode is formed by connecting the common electrode to the common electrode wiring of the first substrate, and the individual electrode is connected to the individual electrode wiring of the second substrate by flip-chip connection, and the second substrate has a window between the two substrates. The image device is formed by arranging and providing a gap as follows and bonding with a transparent adhesive filled in the gap.