JP2851775B2 - 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 generally shown in FIG.
As shown in FIG. 6, a lens plate 21 made of a resin such as polycarbonate in which a plurality of lenses 22 are linearly arranged and supported at predetermined intervals, and a polycarbonate in which a large number of light emitting diode element arrays 23 are linearly arranged and mounted. Each lens 22 and each light emitting diode element array 23 are one-to-one on a pair of supports 25, 25.
The light emitting diode elements 23 of each light emitting diode element array 23
a is selectively emitted individually in response to an external electric signal, and the light emitted by the light emitting diode element 23a is imaged on the surface of an external photoreceptor 26 through a lens 22 to form a photoreceptor.
By forming a latent image on 26, it functions as an image forming apparatus.

The light emitting diode element array 23 mounted linearly on the base plate 24 generally has 64 light emitting diode elements 23a linearly arranged therein, and has a B4 size image. When used in a forming apparatus, the light emitting diode element array 23 is
The individual pieces are placed on the base plate 24 so that each piece corresponds to each lens on a one-to-one basis.

Each of the light emitting diode element arrays 23 has a common electrode on a lower surface thereof. The common electrode is formed on a common electrode wiring previously formed on the upper surface of the base plate 24 by, for example, silver on epoxy resin. The common electrode is mounted on the base plate 24 while being electrically connected to the common electrode wiring by bonding via a conductive resin adhesive to which powder or the like is added.

Further, each light emitting diode element array 23 mounted on the upper surface of the base plate 24 has its individual electrode electrically connected to an individual electrode wiring formed on the upper surface of the base plate 24 via a bonding wire. By connecting the common electrode wiring and the individual electrode wiring on the upper surface of the base plate 24 to an external electric circuit, each light emitting diode element 23a of the light emitting diode element array 23 is electrically connected to the external electric circuit.

Further, when each lens 22 supported on the lens plate 21 and each light emitting diode element array 23 mounted on the base plate 24 are displaced from each other, an image formed on the surface of the photoreceptor 26 is formed. Blurring, white streaks, black streaks, etc. occur, making it impossible to form a clear, accurate latent image, so that each lens 22 and each light emitting diode element array 23 are aligned with extremely high precision. I have.

[0007]

However, in this conventional image device, the light emitting diode element array 23 is provided.
The individual electrodes provided on the base plate 24 are connected to the individual electrode wirings of the base plate 24 via bonding wires. It takes a long time to make an electrical connection to the individual electrode wiring, and the workability of manufacturing the image device is poor, and the image device as a product has the disadvantage of being expensive.

Further, the conductive resin adhesive for bonding and fixing each light emitting diode element array 23 on the base plate 24 requires that heat of 150 ° C. be applied for about one hour for heat curing, and it takes a long time for bonding and fixing. When mounting each light emitting diode element array 23 on the base plate 24, it is easy for displacement to occur at the adhesive fixing position of the light emitting diode element array 23, and when there is a displacement at the fixing position of the light emitting diode element array 23, each light emitting diode element 23a However, it was impossible to form a good image of the emitted light on the external photoreceptor 26 via the lens 22, and a clear and accurate latent image could not be formed on the surface of the photoreceptor 26. .

Further, in the above-mentioned conventional example, an image apparatus used for an image forming apparatus such as an optical printer head has been described as an example. However, a solid-state image sensor array (CCD element array) has been described.
Also 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 non-uniform due to a positional shift between the lens and the solid-state image sensor array, There is a disadvantage that it is impossible to generate an accurate electric signal corresponding to the image information in the solid-state imaging device array.

[0010]

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 element onto a photoreceptor surface via a lens, and to provide a latent image with high image quality on the photoreceptor Or the ability to accurately form external image information on a solid-state image sensor array via a lens, and to generate an accurate electric signal corresponding to the external image information on the solid-state image sensor array. To provide a good image device.

[0011]

According to the present invention, there is provided an image apparatus formed by fixing a lens member composed of a plurality of lenses and an image element member having a large number of image element arrays on a support body. In the image element member, a plurality of image element arrays are linearly arranged between a first substrate having a common electrode wiring and a second substrate having individual electrode wirings, and the common electrode of each image element array is arranged in a first direction. It is characterized in that it is formed by connecting to the common electrode wiring of one substrate via solder and connecting the individual electrode to the individual electrode wiring of the second substrate by flip-chip bonding.

[0012]

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

According to the image apparatus of the present invention, the image element array is mounted on the first substrate by melting and solidifying the common electrode wiring adhered to the first substrate and the common electrode of the image element array. Is performed in a short time and the self-alignment effect (
(The action of attracting each other so that the common electrode wiring attached to the first substrate and the common electrode of the image element array face each other.)
The image element array was mounted very accurately at a predetermined position of the common electrode wiring on the first substrate since the bonding was performed by soldering with solder, and as a result, this image apparatus was used for an image forming apparatus such as an optical printer head. In this case, the center of each lens is always positioned at the center of the light-emitting diode element array, and the light emitted from the light-emitting diode elements of each light-emitting diode element array can be satisfactorily irradiated on the entire surface of the photoconductor. , An accurate latent image can be formed. At the same time, when this image device is used in an image reading device such as an image sensor, since each lens and each image element array always face accurately, external image information is transferred to the solid-state image sensor array via the lens. An image can be accurately formed on the entire surface, and an accurate electric signal corresponding to external image information can be generated in the solid-state imaging device array.

[0014]

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 an opening at the center.

The first substrate 2 of the image element member 1 functions as a support 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-based sintered body, crystallized glass, quartz, or the like. For example, when the first substrate 2 is made of an aluminum oxide-based sintered body, a raw material powder of alumina, silica, calcia, magnesia, or the like is used. An appropriate organic solvent and a solvent are 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 or calendar roll method. The ceramic green sheet is punched into a predetermined shape and
It is manufactured by firing at about 1500 ℃.

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

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 a B4 size optical printer head, the number of the light emitting diode elements 3a is 2048 pieces (8 pieces 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 linearly arranging 32 3, 2048 light-emitting diode elements 3 a are arranged on the first substrate 2.

The mounting of the light emitting diode element array 3 on the first substrate 2 is performed as shown in FIG.
2, a common electrode wiring 2a having a predetermined pattern is previously formed on the upper surface of the light emitting diode array 2, and a common electrode 31 on the lower surface of the light emitting diode element array 3 is joined to the common electrode wiring 2a via solder S. In this case, the solder S melts and solidifies in a short time, and the self-alignment effect, that is,
Since the common electrode wiring 2a attached to the first substrate 2 and the common electrode 31 of the light emitting diode element array 3 are attracted to face each other, the light emitting diode element array 3
Is very accurately mounted at a predetermined position of the common electrode wiring 2a attached to the first substrate 2, so that when this is used as an image forming apparatus, the center of the light emitting diode element array 3 Is always positioned at the center of each lens 7 described later, so that the light emitted from the light emitting diode elements 3a of each light emitting diode element array 3 can be satisfactorily applied to the entire surface of the photoconductor P.

Furthermore, the common electrode wiring 2a formed on the first substrate 2 and the common electrode 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 to the first substrate 2, the solder S is previously applied to the surface of the common electrode wiring 2 a attached to the first substrate 2 by plating. In this case, the light emitting diode element array 3 is mounted so that the common electrode 31 is in contact with the common electrode wiring 2a attached to the first substrate 2 and heat is applied to the mounting portion. Both can be joined by a simple operation, and at the same time, a plurality of light emitting diode element arrays 3 are formed on the first substrate 2 by using solder S previously applied to the surface of the common electrode wiring 2a by plating. When mounted in a straight line, the amount and height of the solder S deposited on the surface of the common electrode wiring 2a by the plating method is uniform, so that each of the light emitting diode element arrays 3 is firmly and identically on the first substrate 2. To be mounted on the first substrate 2 Each light emitting diode array 3 of the light emitting diode elements all the distance between the light emitting diode array 3 and the lens 7 mounted as evenly
The light emitted from 3a can be uniformly and satisfactorily applied to the entire surface of the photoreceptor 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 formed on the first substrate 2 by plating. It is preferable to keep it.

Further, when the light emitting diode element array 3 is mounted on the first substrate 2 via the solder S, cream solder obtained by adding a flux or the like to solder powder is used. 2, cream solder is applied to the surface of the common electrode wiring 2a adhered and formed, and the light emitting diode element array 3 is placed on the cream solder.After that, the cream solder is heated to a predetermined temperature, When the light emitting diode element array 3 is mounted on the first substrate 2 by scattering the solder flux and heating and melting the solder powder, the light emitting diode mounted on the common electrode wiring 2a of the first substrate 2 The element array 3 is always located at a predetermined position due to the temporary fixing action caused by the high viscosity of the cream solder, and as a result, the light emitting diode element array is formed. The ray 3 is always accurately mounted at a predetermined position of the common electrode wiring 2a attached to the first substrate 2. Therefore, the light emitting diode element array
When it is desired to accurately mount 3 on a predetermined position on the first substrate 2 via the solder S, it is preferable to use cream solder as the solder S.

Further, when the light emitting diode element array 3 is mounted on the first substrate 2 via the solder S, the common electrode wiring 2a of the first substrate 2 is connected to each light emitting diode element array as shown in FIG. 3 is formed to keep the common electrode wiring is deposited formed on the first substrate 2 at a region connected with the plurality of islands 2a ₁ and the connecting fine line portions 2a ₂ connecting each island portion 2a ₁
2a and the common electrode 31 of the light emitting diode element array 3 by soldering, the self-alignment effect of the solder S (first
The action of attracting each other so that the common electrode wiring 2a attached to the substrate 2 of the first substrate 2 and the common electrode 31 of the light emitting diode element array 3 face each other increases, and the light emitting diode element array 3 It can be very accurately bonded and mounted at a predetermined position of the common electrode wiring 2a. Therefore, when it is desired to more accurately mount the light emitting diode element array 3 at a predetermined position on the first substrate 2 via the solder S, each of the light emitting diode element arrays 3 is connected to the common electrode wiring 2a of the first substrate 2. The area to be connected is divided into a plurality of islands 2a ₁ and each island
It is preferable to form at the connecting fine line portions 2a ₂ that connects 2a _1.

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

The upper surface of the light emitting diode element array 3 mounted on the first substrate 2 is made of plastic such as glass epoxy resin, has an opening in the center, and has an individual electrode wiring 4a on the lower surface. The attached second substrate 4 is bonded and fixed.

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

The second substrate 4 made of the glass epoxy resin or the like is manufactured, for example, by pouring a sol-like epoxy resin into glass fibers, and then thermally curing the epoxy resin. Electrode wiring 4a
Is formed on the lower surface of the second substrate 4 by employing the same material and the same method as the common electrode wiring 2a provided on the upper surface of the first substrate 2.

An opening provided at the center of the second substrate 4 has a function of transmitting light emitted from each light emitting diode element 3a to a lens member 5 side which will be described later. A predetermined shape is formed at the center of the second substrate 4 by drilling.

Further, 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 at an upper portion 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 a predetermined interval on the upper surface, and the hole 6a is provided for the light emitting diode element array 3.
The light emitted from each of the light emitting diode elements 3a is transmitted to the lens 7.

The lens plate 6 is made 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. If the same material is used, the lens plate 6 can be used even when heat is applied to both the lens plate 6 and the first substrate 2 when used as an image forming apparatus.
6 and the first substrate 2 are thermally expanded by substantially the same amount, and each lens 7 supported by the lens plate 6 and the first substrate 2
No misalignment occurs between each of the light emitting diode elements 3 mounted on the photoconductor P, and as a result, light emitted from each of the light emitting diode elements 3a passes through the lens 7 through the photoconductor P.
An accurate and clear image is formed on the surface, and a high-quality latent image can be formed by the photoconductor P.

Each of the lenses 7 supported by the lens plate 6 receives light emitted by 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 of the lenses 7 is linearly adhered 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 and 8 have 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
The light emitting diode element array 3 and each lens 7 are separated by a predetermined distance by fixing the substrate 2
It has a one-to-one correspondence. In this case, the support
If the first substrate 2 of the image element member 1 that is in contact with the second reference surface 8b of 8 is made of a highly rigid material such as an aluminum oxide sintered body that is unlikely to deform, the support 8 Even when an external force or thermal stress is applied to the first substrate 2 when the image element member 1 is fixed or the like, the first substrate 2 is not deformed such as warpage or torsion. Each light-emitting diode element array 3 mounted on the substrate 2 can always accurately face each lens 7.

Thus, according to the imaging 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 modifications 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 adhered 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 second substrate 4 on which the individual electrode wirings 4a of the image element member 1 are adhered is formed of glass epoxy resin, but this is made of a transparent inorganic material such as glass or a transparent resin such as acrylic resin. It may be formed of plastic. In this case, since the second substrate 4 itself is transparent, the light emitted from the light emitting diode element 3a is applied to the second substrate 4 by a lens member.
There is no need to provide an opening for transmission to the 5 side.

Further, in the above-described embodiment, the case where the present invention is applied to an image forming apparatus such as an optical printer head has been described as an example. However, an image reading apparatus such as an image sensor is used by changing a light emitting diode element array to a solid state image sensor array. Can also be used.

[0043]

According to the image apparatus of the present invention, the individual electrodes of each image element array are electrically connected to the individual electrode wiring provided on the second substrate by flip-chip connection. Even if there are thousands, all of them are 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 apparatus become extremely excellent. .

According to the image apparatus of the present invention, the image element array is mounted on the first substrate by melting and solidifying the common electrode wiring adhered to the first substrate and the common electrode of the image element array. Is performed in a short time and the self-alignment effect (
(The action of attracting each other so that the common electrode wiring attached to the first substrate and the common electrode of the image element array face each other.)
The image element array was mounted very accurately at a predetermined position of the common electrode wiring on the first substrate because of performing the bonding with solder having a certain thickness. As a result, this image device was used for an image forming apparatus such as an optical printer head. In this case, the center of each lens is always positioned at the center of the light-emitting diode element array, and the light emitted from the light-emitting diode elements of each light-emitting diode element array can be satisfactorily irradiated on the entire surface of the photoconductor. , An accurate latent image can be formed. At the same time, when this image device is used in an image reading device such as an image sensor, since each lens and each image element array always face accurately, external image information is transferred to the solid-state image sensor array via the lens. An image can be accurately formed on the entire surface, and an accurate electric signal corresponding to external image information can be generated in the solid-state imaging device array.

[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 partial plan view for explaining a common electrode wiring formed on the first substrate of the image device shown in FIG. 1;

FIG. 5 is a cross-sectional view of a conventional image device.

FIG. 6 is a sectional view taken along line YY of FIG. 5;

[Explanation of symbols]

 DESCRIPTION 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 ... individual electrode wiring 5 ... lens member 6 ... lens plate 7 ... lens 31 ... common electrode 32 ... individual electrode S ... solder

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-137337 (JP, A) JP-A-7-177301 (JP, A) JP-A-6-326683 (JP, A) 3904 (JP, A) JP-A-4-111391 (JP, A) JP-A-52-30108 (JP, A) JP-A-52-4726 (JP, A) JP-A-58-128762 (JP, A) JP-A-4-81067 (JP, A) JP-A-5-121710 (JP, A) JP-A-2-88372 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 1/024-1/036 H01L 27/14

Claims (4)

(57) [Claims] An image device is formed by fixing a lens member comprising a plurality of lenses and an image element member having a large number of image element arrays on a support, wherein the image element member is a common electrode. A plurality of image element arrays are linearly arranged between a first substrate having wiring and a second substrate having individual electrode wiring, and a common electrode of each image element array is connected to a common electrode wiring of the first substrate. Connected via solder to
An image device, wherein the individual electrodes are formed by flip-chip connection to individual electrode wirings of a second substrate. 2. The common electrode wiring of the first substrate, wherein a region to which each image element array is connected is formed by a plurality of islands and a thin connecting line connecting the islands. Item 2. The image device according to Item 1. 3. The method according to claim 1, wherein a solder for connecting the common electrode of each of said image element arrays to the common electrode wiring of the first substrate is applied in advance by plating on the surface of the common electrode wiring. Image device described 4. The image apparatus according to claim 1, wherein the solder for connecting the common electrode of each of the image element arrays to the common electrode wiring of the first substrate is obtained by heating and melting cream solder. .