JPH089100A - Image device - Google Patents

Abstract

PURPOSE:To obtain the inexpensive image device with excellent productivity in which a light emitted from a light emitting diode element is emitted to a photosensitive face via a lens to form accurately a latent image onto the photosensing body with high image quality or an image of external image information is formed accurately on a solid-state image pickup element array via a lens and the solid-state image pickup element array produces an accurate electric signal corresponding to the external image information. CONSTITUTION:The image device is made up of a lens plate 3 supporting plural lenses 3a and a base plate 1 on which lots of image element arrays 2 are mounted by flip chip connection method and the lens plate 3 and the base plate 1 are fixed side by side via a spacer 5 so that each of the lenses 3a and each image element array 2 are corresponding one to one to each other, and the lens plate 3 is made of a regenerative material with a low thermal expansion coefficient and a template 4 made of a regenerative material with a low thermal expansion coefficient to restrict the position of the image element array 2 is fitted to the surface of the base plate 1.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A conventional image forming apparatus, for example, an image forming apparatus used in an image forming apparatus such as an optical printer head, usually has a lens made of a resin such as polycarbonate in which a plurality of lenses are linearly arranged and supported at predetermined intervals. The plate and the base plate made of aluminum oxide sintered body or glass in which a large number of light emitting diode element arrays are linearly mounted are arranged so that each lens and each light emitting diode element array have a one-to-one correspondence. It has a fixed structure, and each light emitting diode element of each light emitting diode element array is caused to selectively emit light in response to an external electrical signal, and the light emitted by the light emitting diode element is passed through a lens. An image is formed on an external photoconductor, and a latent image is formed on the photoconductor to function as an image forming apparatus.

A light-emitting diode element array linearly arranged and mounted on the base plate generally has 64 light-emitting diode elements linearly arranged therein, which is suitable for a B4 size image forming apparatus. When used, the 32 light emitting diode element arrays are mounted on the base plate such that 32 of them correspond to the respective lenses one to one.

Further, in each light emitting diode element of the light emitting diode element array linearly mounted on the base plate, each electrode thereof is electrically connected to the electrode wiring previously attached to the surface of the base plate through a bonding wire. By connecting the electrode wiring on the surface of the base plate to the external electric circuit, each light emitting diode element is connected to the external electric circuit via the electrode wiring and the bonding wire.

[0005]

However, in this conventional image device, each electrode of the light emitting diode element array is connected to the electrode wiring of the base plate through a bonding wire, and the number of electrodes of the light emitting diode element array is Since the number of electrodes is extremely large (thousands), it takes a long time to electrically connect the electrodes of the light-emitting diode element array to the electrode wiring of the base plate, the manufacturing workability of the image device is poor, and the image device is expensive Had.

Therefore, in order to solve the above-mentioned drawbacks, the applicant has previously applied electrode wiring to the surface of the base plate in advance and connected each electrode of the image element array to the electrode wiring by flip-chip connection. Proposed a device.

According to such an image device, since the electrodes of the image element array are connected to the electrode wirings attached to the base plate by flip chip connection, even if there are thousands of electrodes of the image element array, all of them are of the base plate. It is electrically connected to the electrode wiring at once and firmly, and as a result, the productivity and reliability of the image device are extremely excellent.

However, in this image device, when the electrodes of the image element array are connected to the electrode wirings of the base plate by flip-chip connection, the number of electrodes of the image element array is as large as several thousand and the shape of each electrode is extremely small. It is difficult to bring each electrode into proper contact with a predetermined electrode wiring, and an erroneous connection easily occurs. When the erroneous connection occurs, a desired latent image can be formed on the photoconductor when used as an image forming apparatus. In addition, when it is used as an image reading device, it causes a defect that the external image information cannot be read accurately.

Further, in this conventional image pickup apparatus, the coefficient of thermal expansion of the lens plate made of resin such as polycarbonate for supporting the lens and the base plate made of glass such as aluminum oxide sintered body on which the light emitting diode element array is mounted are arranged. 1.9 × 10 ^-5 / ℃, 4.0 × 10 ^{-6, respectively}
/ ℃ ~ 7.5 × 10 ^-6 / ℃, which is a big difference, so when the heat of the fixing device of the electrophotographic printer or the heat generated during the operation of the light emitting diode element array is applied, the lens plate becomes the base plate. As a result, thermal expansion greatly occurs, and as a result, a positional deviation occurs between the lens supported by the lens plate and the light emitting diode element array mounted on the base plate, and a clear and accurate latent image can be formed on the photoconductor surface. It also had the drawback of not being able to.

In the above embodiment, the image forming apparatus used in the image forming apparatus such as the optical printer head has been described as an example. However, in the image reading apparatus such as the image sensor using the solid-state image sensor array, etc. The image device used has the same drawbacks.

[0011]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above drawbacks, and its purpose is to irradiate the surface of the photoconductor with light emitted from a light emitting diode element through a lens to form a latent image of high image quality on the photoconductor. Production that can be accurately formed, or that can accurately form an external image information on a solid-state image sensor array through a lens and generate an accurate electric signal corresponding to the external image information on the solid-state image sensor array. It is to provide an inexpensive imaging device with good performance.

[0012]

The present invention comprises a lens plate supporting a plurality of lenses, and a base plate in which a large number of image element arrays are arrayed and mounted by a flip chip connection method, and the lens plate and the base plate are provided. Is an image device in which each lens and each image element array are fixed side by side through a spacer so as to correspond to each other in a one-to-one correspondence, wherein the lens plate has a heat storage property and a low thermal expansion coefficient, and the surface of the base plate. In addition, a template having a heat storage property and a low coefficient of thermal expansion that regulates the position of the image element array is attached.

[0013]

According to the image device of the present invention, the electrodes of the image element array are electrically connected to the electrode wirings attached to the base plate by flip-chip connection. Therefore, even if there are thousands of electrodes of each image element array, Everything is electrically connected to the electrode wiring of the base plate at once and firmly, and as a result, the productivity of the image device becomes extremely excellent, and the image device as a product becomes inexpensive.

Further, according to the image device of the present invention, since the template for regulating the position of the image element array is attached to the surface of the base plate, the electrodes of the image element array are connected to the electrode wiring of the base plate by flip chip connection. At this time, even if the position of the image element array is regulated by the template and there are thousands of electrodes of each image element array, all of them can be brought into contact with the predetermined electrode wiring of the base plate easily and accurately. Since each electrode of the element array can be accurately and firmly electrically connected to a predetermined electrode wiring, the productivity and reliability of the image device can be made extremely excellent.

Further, according to the image device of the present invention, the lens plate has a heat storage property and a low thermal expansion coefficient, and the template for restricting the position of the image element array attached to the surface of the base plate has a heat storage property and a low thermal expansion coefficient. Therefore, even if heat is applied to both the lens plate and the base plate, the heat is not absorbed by the lens plate and the template and does not cause abnormal thermal expansion in the lens plate and the base plate. The array and the lens always face each other accurately, whereby the light emitted from the light emitting diode element can be accurately irradiated onto the surface of the photoconductor through the lens, and a latent image with high image quality can be accurately formed on the photoconductor, or External image information is accurately formed on the solid-state image sensor array through the lens, It is possible to generate an accurate electrical signal corresponding to the image information.

[0016]

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

The base plate 1 is made of an electrically insulating material such as an aluminum oxide sintered body, crystallized glass, quartz or glass epoxy resin, and a plurality of light emitting diode element arrays 2 are linearly arranged and mounted on the lower surface thereof. ing.

The base plate 1 acts as a supporting member for supporting the light emitting diode element array 2, and as shown in FIG. 3, the electrodes 2b of each light emitting diode element array 2 are flipped to the electrode wiring 1a attached to the base plate 1. Chip connection, specifically, the light emitting diode element array 2 on the upper surface of the base plate 1, the electrode wiring 1a attached to the base plate 1 and each electrode 2b of the light emitting diode element array 2
By placing solder so as to face each other with solder sandwiched between them, and then heating and melting the solder to solder-bond each electrode wiring 1a of the base plate 1 and each electrode 2b of the light-emitting diode element array 2 to each other. The light emitting diode element arrays 2 are mounted on the lower surface of the base plate 1 in an array. At this time, even if the total number of each electrode 2b of each light emitting diode element array 2 is several thousands, all of them are soldered to the electrode wiring 1a attached to the surface of the base plate 1 at a time, and Because of the strong electrical connection, each electrode 2b of the light emitting diode element array 2 and the base plate 1
The electrical connection with the electrode wiring 1a can be made in an extremely short time, and the workability and productivity of assembling the image device are greatly improved.

The base plate 1 is made of an aluminum oxide sintered body, crystallized glass, quartz, glass epoxy resin or the like. When it is made of an opaque material such as an aluminum oxide sintered body, an opening is formed in the central portion. In the case where the opening is provided as a window portion for forming a light path between the light emitting diode element array 2 and the lens 3a supported by the lens plate 3 described later, and is made of a transparent material such as crystallized glass or quartz. The central region of the light-emitting diode itself serves as a window for forming a light passage between the light-emitting diode element array 2 and the lens 3a.

When the base plate 1 is made of an opaque material such as an aluminum oxide sintered body, the center plate of the base plate 1 is perforated using a laser or the like so that the light emitted from each light emitting diode element 2a is made into a lens.
An opening is formed in a predetermined shape as a window portion through which the light is transmitted to the 3a side.

Further, the electrode wiring 1a previously deposited on the surface of the base plate 1 functions to connect each electrode 2b of the light emitting diode element array 2 to an external electric circuit, and the surface of the base plate 1 is made of aluminum, copper or the like. A base plate is formed by applying a conductive material to a predetermined thickness by plating, vapor deposition, sputtering, etc., processing this into a predetermined pattern by etching, and then nickel plating, gold plating, or solder plating on the surface. 1 is deposited on the surface.

The base plate 1 is also coated with a template 4 for regulating the position of the light emitting diode element array 2 on the surface on which the electrode wiring 1a is deposited.

Since the template 4 regulates the position of the light emitting diode element array 2, when the electrode 2b of the light emitting diode element array 2 is connected to the electrode wiring 1a of the base plate 1 by flip chip connection, Even if there are thousands of electrodes, all of them can be brought into contact with the predetermined electrode wiring 1a of the base plate 1 easily and accurately, and as a result, each electrode 2b of the light emitting diode element array 2 can be accurately connected to the predetermined electrode wiring 1a. As a result, it is possible to make a strong electrical connection, and the productivity and reliability of the image device become extremely excellent.

Further, the template 4 is made of a liquid crystal polymer or a crystallized glass that is etched, and the liquid crystal polymer or the like has a heat storage property and a low thermal expansion coefficient (2 × 10 5
^-6 / ° C or less), the light emitting diode element array 2 and the light emitting diode element array 2 are mounted on the base plate 1.
Even if the heat generated by the driving IC that drives the LED is applied, the heat is not absorbed by the template 4 and causes abnormal thermal expansion in the base plate 1. As a result, each light emitting diode element array 2 is always It exactly faces the lens 3a, so that the light emitted from the light emitting diode element 2a is accurately irradiated onto the surface of the photoconductor P through the lens 3a,
A latent image with high image quality can be accurately formed on the photoconductor P.

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

The light emitting diode element 2a is a GaAsP type, Ga
P-based light-emitting diodes are used, for example, in the case of a GaAsP-based light-emitting diodes, as well as heating to a high temperature the GaAs substrate at furnace First AsH ₃ and (arsine) PH ₃ and (Hosuhin) Ga (gallium ) Is contacted with a gas to grow a single crystal of n-type semiconductor GaAsP (gallium-arsenic-phosphorus) on the substrate surface, and then Si ₃ is grown on the GaAsP single crystal surface.
A windowed film of N ₄ (silicon nitride) is deposited, and Zn (zinc) gas is exposed to the window to form an n-type semiconductor GaAsP.
Zn is diffused into a part of the single crystal to form a p-type semiconductor, and pn
It is formed by providing a bond.

In the case of a B4 size optical printer head, the number of the light emitting diode elements 2a is 2048 (8 per 1 mm).
Are arranged in a straight line, specifically, a light emitting diode element array in which 64 light emitting diode elements 3a are one unit.
32 light emitting diode elements 3a are linearly arranged, and thus 2048 light emitting diode elements 3a are arranged and mounted on the base plate 1.

The base plate 1 on which the light emitting diode element array 2 is arranged and mounted is provided with a lens plate 3 on the upper part of the base plate 1 at a constant distance, and a plurality of holes are linearly arranged in the lens plate 3. The lens 3a is formed so as to cover the hole while being formed.

The lens plate 3 includes a plurality of lenses 3a.
Function as a supporting member for supporting the light emitting diode elements of the light emitting diode element array 2 at a predetermined interval.
The light emitted by 2a is transmitted to the lens 3a and the lens 3a
It performs the function of positioning.

The lens plate 3 is made of a material having a heat storage property and a low coefficient of thermal expansion such as liquid crystal polymer, and has a heat storage property and a low coefficient of thermal expansion.
Even if heat generated by the light emitting diode element array 2 or a driving IC for driving the light emitting diode element array 2 is applied to the lens element, the heat is not well absorbed in the lens plate 3 and does not significantly expand. As a result, each lens 3a is always accurately opposed to each light emitting diode element array 2 so that the light emitted by the light emitting diode element 2a is accurately irradiated onto the surface of the photoconductor P through the lens 3a, and the image is formed on the photoconductor P. It is possible to accurately form a high-quality latent image.

Further, each lens 3a supported by the lens plate 3 transmits light emitted from each emitting diode element 2a to the photoconductor P.
A lens formed of a transparent resin such as an acrylic resin or a polycarbonate resin or a transparent inorganic material such as glass, which has the function of irradiating the surface, is preferably used.

Each lens 3a is fixed to the lens plate 3 linearly at a predetermined interval by fitting a part of the outer surface of the lens 3a into a hole provided in the lens plate 3 and adhering it through an adhesive. . In this case, since each lens 3a is fitted into the hole of the lens plate 3, the fixing position of the lens 3a on the lens plate 3 becomes extremely accurate,
This also allows the lenses 3a and the light emitting diode element arrays 2 to be accurately opposed to each other.

Further, the base plate 1 on which the light emitting diode element array 2 is mounted and the lens plate 3 having a plurality of lenses 3a are fixed to the spacer 5 so that each light emitting diode element array 2 and each lens 3a are separated from each other. They are installed side by side in a one-to-one correspondence with a predetermined distance.

The spacer 5 has a first alignment reference surface 5a on the top thereof and a second alignment reference surface 5b on the bottom thereof, and the first alignment reference surface 5a of the spacer 5 is on the lower surface of the lens plate 3. By fixing the outer peripheral portion of the upper surface of the base plate 1 to the second alignment reference surface 5b so as to correspond one-to-one with a predetermined distance between each light-emitting diode element array 2 and each lens 3a. Has become. The spacer 5 is made of, for example, glass epoxy resin or the like.

Thus, according to the image device of the present invention, a predetermined power is applied to each light emitting diode element 2a arranged and mounted on the base plate 1 to cause each light emitting diode element 2a to selectively emit light individually. The light emitted from the light emitting diode element 2a forms an image on the surface of the external photoconductor P via the lens 3a and forms a predetermined latent image on the photoconductor P, thereby functioning as an image forming apparatus.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiments, an optical printer head, etc. However, the light emitting diode element array may be replaced with a solid-state image pickup element array to be used in an image reading apparatus such as an image sensor.

[0037]

According to the image device of the present invention, since the electrodes of the image element array are electrically connected to the electrode wirings adhered to the base plate by flip chip connection, it is assumed that there are thousands of electrodes of each image element array. All of them will be electrically connected to the electrode wiring of the base plate at once and firmly, and as a result, the productivity of the image device will be extremely excellent, and the image device as a product will be inexpensive.

Further, according to the image device of the present invention, since the template for regulating the position of the image element array is attached to the surface of the base plate, the electrode of the image element array is connected to the electrode wiring of the base plate by flip chip connection. At this time, even if the position of the image element array is regulated by the template and there are thousands of electrodes of each image element array, all of them can be brought into contact with the predetermined electrode wiring of the base plate easily and accurately. Since each electrode of the element array can be accurately and firmly electrically connected to a predetermined electrode wiring, the productivity and reliability of the image device can be made extremely excellent.

Furthermore, according to the image device of the present invention, the lens plate has a heat storage property and a low thermal expansion coefficient, and the template for restricting the position of the image element array attached to the surface of the base plate has a heat storage property and a low thermal expansion coefficient. Therefore, even if heat is applied to both the lens plate and the base plate, the heat is not absorbed by the lens plate and the template and does not cause abnormal thermal expansion in the lens plate and the base plate. The array and the lens always face each other accurately, whereby the light emitted from the light emitting diode element can be accurately irradiated onto the surface of the photoconductor through the lens, and a latent image with high image quality can be accurately formed on the photoconductor, or External image information is accurately formed on the solid-state image sensor array through the lens, It is possible to generate an accurate electrical signal corresponding to the image information.

[Brief description of drawings]

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

2 is a cross-sectional view of FIG.

3 is a partially enlarged cross-sectional view for explaining a state in which an image element array is mounted on a base plate in the image device shown in FIG.

[Explanation of symbols]

 1 ... Base plate 1a ... Electrode wiring 2 ... Light emitting diode element array 2a ... Light emitting diode element 2b ... Electrode 3 ... Lens plate 3a ... Lens 4 ... Template 5 ... Spacer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41J 2/455 H01L 27/146 // H04N 1/028 Z

Claims (1)

[Claims] 1. A lens plate for supporting a plurality of lenses, and a base plate in which a large number of image element arrays are arrayed and mounted by a flip-chip connection method. The lens plate and the base plate are provided with a spacer between each lens and each lens. An image device in which image element arrays are fixed together so as to have a one-to-one correspondence, wherein the lens plate has heat storage properties and a low coefficient of thermal expansion, and the position of the image element array is regulated on the surface of the base plate. An image device characterized in that a template having a heat storage property and a low coefficient of thermal expansion is attached.