JPH077832B2 - Photoelectric conversion device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photoelectric conversion device, and is particularly suitable for application to a photoelectric conversion device provided with a photoelectric conversion element (photosensor) array.

[Prior Art] Japanese Patent Application Laid-Open No. Sho 60 has been proposed as a device in which the photoelectric conversion device is downsized and the yield is improved to reduce the manufacturing cost.
-132452 and JP-A-62-97370. In these, a support body (hereinafter referred to as a mounting board) in which a sensor board provided with an optical sensor is created in another process
A configuration for carrying on top is disclosed.

[Problems to be Solved by the Invention] However, the following problems have occurred in these conventional examples.

First, in Japanese Unexamined Patent Publication No. 60-132452, a thick film circuit as a drive circuit unit is formed on an insulating ceramic substrate as a mounting substrate, and an optical sensor array unit is fixed on the mounting substrate. A configuration in which the optical sensor array unit and the optical sensor array unit are connected by a wire bonding method is shown. However, in this configuration, since the mounting substrate is non-translucent, the arrangement of the light sources is restricted, and there is a possibility that sufficient miniaturization cannot be achieved.

On the other hand, in Japanese Patent Laid-Open No. 62-97370, a translucent sensor substrate on which an optical sensor array is formed is fixed on a translucent mounting substrate, and an opaque resin is placed on the optical sensor. The molded configuration of is shown. A light-shielding plate is provided on the light-transmitting mounting substrate and the light-transmitting sensor substrate to prevent the incidence of unnecessary light rays while receiving the information light on the optical sensor through the light-transmitting mounting substrate and the light-transmitting sensor substrate. However, in this configuration, since the information light from the document surface passes through the light-transmissive mounting substrate and the light-transmissive sensor substrate and enters the light receiving element (optical sensor), the information light up to the optical sensor There is a possibility that the arrival path becomes long and a light amount loss is likely to occur, and stray light components are generated due to diffused light in each layer, resulting in a decrease in S / N ratio and a decrease in sensor output.

By the way, when the light source of the photoelectric conversion device has uneven light quantity,
Since there are variations in the output signal of the sensor, and in some cases white stripes or black stripes may appear and a read error may occur, as a technique for improving this, for example, Japanese Patent Laid-Open No. 63-3
There is something like that disclosed in 10262. This is a configuration in which a light control member (lighting curtain) is provided in the optical path between the light source and the document. This lighting curtain is in the form of a light-shielding film provided on the film in a pattern such that the light amount distribution is constant, and is corrected so that the illumination light on the document surface has a uniform distribution. It

However, in this conventional example, since the lighting curtain is provided as a separate member, there is a possibility that the alignment accuracy between the lighting curtain and the light source may not be ensured, and the provision of the separate member may increase the cost.

[Means for Solving the Problems] An object of the present invention is to solve these problems, and for that purpose, a photoelectric conversion element is provided on the side of the surface facing the original for reading image information to improve the translucency. And a wiring member for supporting the substrate and having a light-transmitting property, the wiring member for connecting the photoelectric conversion element and a circuit for driving the photoelectric conversion element on the supporting surface of the substrate, and at least the wiring member. The support has a dimming part formed of a part of the same material, and a light source provided on the surface of the support opposite to the support surface of the substrate, and the light emitted from the light source is the support. The original is irradiated through the light control section and the substrate, and the reflected light is received by the photoelectric conversion element.

[Operation] According to the present invention, since the illumination light is transmitted through the translucent mounting substrate (support), the degree of freedom in the arrangement of the light source is improved, and the size can be reduced. (Reflected light from) does not pass through the transparent mounting substrate and the substrate (transparent sensor substrate), so there is no loss or diffusion of the information light, and the S / N ratio is improved, and the sensor output Also improves. In the present invention, since the illumination light is transmitted through the substrate and the mounting substrate, the illumination light does not adversely affect each sensor due to an appropriate loss and diffusion of the light when the illumination light is transmitted, and the illumination light is evenly distributed on the original. You can do various lighting.

In addition, by forming the light control part, which was a separate member in the past, using at least a part of the same material as the wiring member, both can be formed on the mounting board in the same process, enabling downsizing and cost reduction. Become.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of a photoelectric conversion device to which the present invention can be applied. Here, the translucent sensor substrate 1 has an optical sensor array formed by a semiconductor process or the like on a translucent and insulating substrate such as quartz glass or borosilicate glass. The translucent mounting substrate 2 is translucent such as quartz glass, borosilicate glass, soda glass, or acrylic (which may be provided with a protective film such as SiO ₂ for preventing elution or diffusion of alkali elements). Ag, Ag-Pd.Ag-Pd, Au formed by thick-film printing method on a substrate having insulating and insulating properties
Etc., or Al, Cu, formed by photolithography
It has a wiring section 4 such as Mo or ITO. Further, as will be described later with reference to FIGS. 5 and 6, a dimming pattern is formed on the substrate 2. The bases of these substrates 1 and 2 have similar thermal expansion coefficients.

The wiring section 4 connects the sensor section and a drive circuit section (not shown). Then, the transparent sensor substrate 1 is mounted on the transparent mounting substrate 2.
Are bonded by the adhesive layer 5. For the adhesive layer 5, a translucent adhesive such as a silicon-based, acryl-based, or epoxy-based room temperature or heat-curable type or photo-curable type is preferably used, and the translucent sensor substrate 1 and the translucent mounting substrate 2 are used. The material of which the thermal expansion coefficient and the optical refractive index are similar to those of the respective substrates is used.

The translucent sensor substrate 1 and the wiring portion 4 of the translucent mounting substrate 2 are electrically connected by wire bonding, soldering, or the like.

Thus, the illumination light L from the light source 3 is transmitted through the translucent mounting substrate 2 and the translucent sensor substrate 1 and applied to the document 6,
The information light reflected from the document 6 enters the light receiving element on the translucent sensor substrate 1 and is output as an image signal from the light receiving element.

According to this example, the information light is emitted from the mounting substrate 2 and the sensor substrate 1.
Since the light is received by the optical sensor without passing through, there is no loss of light amount or reduction of the S / N ratio due to stray light components. Further, according to this example, the translucent sensor substrate 1 and the translucent mounting substrate 2 can be handled as independent components, that is, they can be manufactured in different processes, and therefore the manufacturing process is unified. It becomes possible to use only non-defective products in each separate inspection process, which improves the overall yield. In addition, only the optical sensor unit
Since it is arranged on the base body of No. 2, it is possible to manufacture a large number of substrates 1 in a batch with the base material having a certain spread, and the cost can be reduced. Further, on the translucent mounting board 2, in addition to the wiring section 4, a driving IC chip and an output amplification
It is also possible to mount an IC chip or the like, in which case further cost reduction is possible. Further, by arranging the light source 3 on the back surface side of the translucent mounting substrate 2, the unit outer size is further reduced.

That is, according to the present embodiment, since the illumination light is transmitted through the translucent mounting substrate, the degree of freedom in arranging the light source is improved, that is, the light source is disposed on the back surface side of the translucent mounting substrate. It becomes possible, and further miniaturization of the device to which the photoelectric conversion device is applied can be achieved.

In addition, since the information light does not pass through the transparent mounting substrate and the transparent sensor substrate, there is no loss or diffusion of the information light and the S / N ratio is improved and the sensor output is good. Becomes

Furthermore, by using a base body made of a material having a similar thermal expansion coefficient for the translucent mounting substrate and the translucent sensor substrate, it is possible to relieve the stress generated by the joining of the two and to prevent the warpage and cracking of the substrate. .

In addition, since the wiring portion is provided on the translucent mounting substrate, downsizing of the device is achieved. If the wiring portion is provided between the translucent mounting substrate and the translucent sensor substrate, further It can be downsized.

2A and 2B are respectively an exploded perspective view and a sectional view showing another embodiment of the photoelectric conversion device to which the present invention can be applied. This example is an example in which a light shielding layer 7 is provided between the translucent mounting substrate 2 and the translucent sensor substrate 1.

Here, the light-shielding layer 7 is arranged around the slit-shaped window portion 7A appropriately determined according to the optical path L, and can be formed by the same process and the same metal material as the wiring portion 4. However, it may be formed of a non-translucent resin by a screen printing method or a dispensing method. Alternatively, the light-shielding layer 7 may be formed by using an opaque adhesive agent for adhering the translucent mounting substrate 2 and the translucent sensor substrate 1, and in this case, a step of interposing an adhesive agent separately. Is unnecessary.

The light-shielding layer 7 formed as described above is formed on a portion of the translucent mounting substrate 2 excluding the optical path of the illumination light L and has a slit window portion 7A for light incidence. The slit-shaped window portion may be left as a void or may be filled with a transparent resin. Further, a dimming pattern portion is formed in a portion corresponding to the window portion 7A on the mounting substrate 2 as described later with reference to FIGS. 5 and 6.

In any case, according to the configuration as shown in FIG. 2, in addition to the same effect as that shown in FIG.
By blocking stray light that causes noise in the signal output, for example, diffused reflection component on the translucent mounting substrate 2 in the illumination light from the light source, the resolution of the output signal can be improved.

FIG. 3 shows a more detailed sectional structure of the photoelectric conversion device according to the embodiment of FIG. 1 or 2.

Here, the matrix wiring portion 9, the illumination window 10, the light receiving element 11, the charge accumulating portion (capacitor portion) 12, and the accumulated electric charge are appropriately provided on the base body 1 ′ formed of translucent glass or the like. An optical sensor including a switching thin film transistor (TFT) 13 for timing transfer is integrally formed. The translucent sensor substrate 1 thus configured is supported on the translucent mounting substrate 2 through the adhesive layer 5 or the light shielding layer 7 (the optical path portion is the window 7A). All of these parts can be formed by the same manufacturing process. The layer structure of each part is, for example, made of Cr on the base body, the light shielding layer lower electrode 15 of the sensor part, the insulating layer of silicon hydronitride (SiNx: H) arranged on the lower electrode, and the hydrogenated amorphous film on the upper part thereof. Silicon (a-Si: H) semiconductor layer,
It is composed of an n ⁺ a-Si: H ohmic layer on the upper part and an upper electrode such as Al arranged on the ohmic layer.

The optical sensor portion having such a configuration is covered with the passivation layer 19, and the thin glass sheet 14 having a thickness of, for example, 50 μm is provided on the passivation layer 19 via the adhesive layer 20. The document slides on the thin glass plate 14, and the thin glass plate 14 functions as a spacer layer for keeping the distance between the light receiving element 11 and the document 6 constant and also as a wear resistant layer.

In such a configuration, the illumination light L emitted from the back side of the translucent mounting substrate 2 passes through the translucent mounting substrate 2 and the translucent sensor substrate 1, passes through the illumination window 10 and is placed on the thin glass plate 14. The original 6 is illuminated. Then, the information light L ′ reflected by the original 6 enters the light receiving element 11.

FIG. 4 is an exploded perspective view showing an example of a unitized structure of the photoelectric conversion device having the above-described basic structure.
5A is a plan view of the sensor unit, FIG. 5B is a side view of the same, FIG. 5C is a rear view of the same, and FIG. The same drawing (E) is a sectional view taken along the line EE '. In the illustrated example, the translucent sensor substrate 1 is adhered and fixed onto the translucent mounting substrate 2, the translucent mounting substrate 2 is fixed to the base plate 22, and further pressed by the IC cover 23. Next is the base plate
The light source 3 is fixed to the lower surface of 22. Then, the image signal can be output from the unit via the flexible wiring 24 and the connector 25.

FIGS. 6 (A) and 6 (B) show an example of a dimming pattern portion applicable to the configuration as shown in FIGS. 1 and 2. In this example, the dimming pattern 26A is formed in the dimming pattern forming portion 26 by the same material in the optical path of the illumination light on the translucent mounting substrate 2 at the same time as the step of forming the wiring portion 4. The light control pattern portion 26 is made of a thin film of Al, Cr, Ta, Ti or the like, or an electrode material for thick film printing of a conductive paste (Ag, carbon, etc.), and is used for the light source 3 (LED,
The pattern density, size, pitch, etc. are appropriately determined according to the variation in the amount of light of the Xe tube, fluorescent tube, EL, etc., so that the illuminance distribution on the document surface is made uniform.

FIGS. 7A and 7B show another example of the dimming pattern. In this example, the wiring part 4 on the translucent mounting substrate 2 is configured to cross the optical path of the illumination light, and the optical path part of the wiring part 4 is provided with a dimming pattern 46 in which the line width is determined according to the light amount distribution of the light source. Form. Further, a light control pattern 27, which is a dummy wiring pattern, is formed on the optical path portion other than the light control pattern portion 46 by the wiring portion 4.

FIG. 8 shows the light quantity distribution when the dimming pattern as shown in FIG. 6 or 7 is formed (after shading) and when it is not provided (before shading).

As is clear from the figure, when the dimming pattern was applied, a good and uniform light amount distribution was obtained over the array range of the photoelectric conversion elements (sensor bits). Therefore, the original surface is illuminated by the uniform illumination light, and the read image becomes good.

Furthermore, the sensor unit 10 configured as described above
By using 0, it is possible to configure various devices such as a facsimile device and an image reader.

FIG. 9 shows an example of an image processing apparatus (for example, a facsimile) configured by using the sensor unit 100 according to this example.

Here, 102 is a feeding roller for feeding the originals 6 toward the reading position, and 104 is a separating piece for surely separating and feeding the originals 6 one by one. A platen roller 106 is provided at a reading position so as to face the sensor unit 100, regulates a surface to be read of the original 6, and conveys the original 6.

P is a recording medium in the form of roll paper in the illustrated example,
Image information read by the sensor unit 100 or image information transmitted from the outside in the case of a facsimile machine or the like is formed. Reference numeral 110 denotes a recording head for performing the image formation, and various types such as a thermal head and an inkjet recording head can be used. The recording head may be of a serial type or a line type. A platen roller 112 conveys the recording medium P to the recording position of the recording head 110 and regulates the recording surface of the recording medium P.

An operation panel 120 is provided with a switch for receiving an operation input, a display unit for notifying a message and other device states. A system control board 130 is provided with a control section for controlling each section, a drive circuit section of an optical sensor, an image information processing section, a transmission / reception section, and the like.
140 is the power supply of the device.

In the above embodiments, the configuration is described in which the original is closely contacted with or close to each other without the optical system interposed between the photoelectric conversion device and the original 6, and the reading is performed. The present invention can be effectively applied to a configuration in which (light) is imaged on a light receiving element via an optical system.

That is, as shown in FIG. 10, even if the optical system member 8 such as a converging optical transmission body array or a fiber plate is used between the translucent sensor substrate 1 and the original 6,
The present invention can be easily applied.

[Effect of the Invention] As described above, according to the present invention, according to the present embodiment, since the illumination light is transmitted through the mounting substrate having a light transmitting property, the degree of freedom in the arrangement of the light source is improved. That is, the light source can be arranged on the back surface side of the translucent mounting substrate, and further miniaturization of the device to which the photoelectric conversion device is applied can be achieved.

In addition, since the information light does not pass through the transparent mounting substrate and the transparent sensor substrate, there is no loss or diffusion of the information light and the S / N ratio is improved and the sensor output is good. Becomes

Furthermore, according to the present invention, since the dimming pattern portion is formed on the translucent mounting substrate, for example, in the same step and with the same material as the wiring portion, there is no need to provide a separate lighting curtain. Since there is no need for an assembly process,
It is possible to reduce the size and cost of the device.

In addition, since the dimming pattern portion on the translucent mounting substrate can be formed by the wiring portion itself, further miniaturization is possible, and the degree of freedom in designing the arrangement of IC chips and the like is also improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a photoelectric conversion device according to an embodiment of the present invention, and FIGS. 2A and 2B are exploded perspective views of a photoelectric conversion device according to another embodiment of the present invention. FIG. 3 and a schematic cross-sectional view, FIG. 3 is a more detailed cross-sectional view of the photoelectric conversion device according to the embodiment of FIG. 1 or FIGS. 2 (A) and (B), and FIG. Exploded perspective view showing an example of the configured sensor unit, FIGS. 5 (A), (B), (C), (D) and (E).
Are the plan view, side view, and
A rear view, a DD line sectional view and an EE ′ line sectional view, and FIGS. 6 (A) and 6 (B) respectively show a photoelectric conversion device for showing an embodiment of a dimming pattern according to the main part of the present invention. FIGS. 7A and 7B are an exploded perspective view and a plan view of a mounting board, respectively, showing an exploded perspective view of a photoelectric conversion device and another plan view of a mounting board for showing another embodiment of a dimming pattern. FIG. 8 is a diagram showing a light amount distribution depending on the presence or absence of a dimming pattern, FIG. 9 is a sectional view showing an example of an image processing apparatus to which the present invention can be applied, and FIG. 10 is still another embodiment of the present invention. It is a schematic cross-sectional view showing. 1 ... Translucent sensor substrate, 2 ... Translucent mounting substrate (support), 3 ... Light source, 4 ... Wiring portion, 5 ... Adhesive layer, 6 ... Original document, 7 ... Shading layer, 7A: window, 8: optical system member, 26: dimming pattern forming part, 26A, 46, 27: dimming pattern.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayoshi Murata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-63-310261 (JP, A) JP-A-63 -310262 (JP, A) JP-A-63-310263 (JP, A)

Claims (4)

[Claims] 1. A substrate provided with a photoelectric conversion element on the side facing a document for reading image information, the substrate having a light-transmitting property, and a support having a light-transmitting property for supporting the substrate, A support having a wiring member for connecting the photoelectric conversion element and a circuit for driving the photoelectric conversion element on a support surface of the substrate, and a light control section formed at least partially of the same material as the wiring member. And a light source provided on a surface side of the support opposite to the support surface of the substrate, the light emitted from the light source is transmitted through the support, the light control section and the substrate, and the original document is provided. The photoelectric conversion device is characterized in that the photoelectric conversion element is irradiated with light and is reflected by the photoelectric conversion element. 2. The photoelectric conversion device according to claim 1, wherein the light control section is patterned in the same step as the wiring member. 3. The photoelectric conversion device according to claim 2, wherein at least a part of the wiring member is also used as the light control section. 4. The photoelectric conversion device according to claim 1, wherein the light control unit is formed in a pattern that makes the variation in the light amount uniform.