JPH02226953A - Photoelectric converter - Google Patents

Abstract

PURPOSE:To attain the miniaturization of a device to which a photoelectric converter is applied by adopting the constitution such that a lighting light transmits through a mount board having transparency. CONSTITUTION:A transparent sensor board 1 has an optical sensor array made by the semiconductor process or the like on its transparent and insulating board made of a quartz glass or a borosilicate glass or the like. A transparent mount board 2 has a wiring part 4 made of Ag, Ag-Pd, Ag-Pt or Au or the like formed by the thick film print method or Al, Cu, Mo, ITO or the like formed by the photo lithography method on the transparent and insulating board made of quartz glass, borosilicate glass, soda glass or acryl or the like. A light source 3 is arranged on the rear side of the transparent mount board 2 to make the unit outer size further smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photoelectric conversion device, and is particularly applicable and suitable for a photoelectric conversion device provided with a photoelectric conversion element (photosensor) array.

[Prior art] As a device that miniaturizes photoelectric conversion devices, improves yield, and reduces manufacturing costs, etc.,
There are those disclosed in No. 0-132452 and Japanese Patent Application Laid-Open No. 62-97370. These disclose a configuration in which a sensor substrate provided with an optical sensor is supported on a support (hereinafter referred to as a mounting substrate) prepared in another process.

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

First of all, Tokukai Akira [! In No. 0-132452, a thick film circuit as a drive circuit is formed on an insulating ceramic substrate as a mounting board, a photosensor array part is fixed on the mounting board, and the thick film circuit and the photosensor array part are bonded together. A configuration in which these are connected by wire bonding is shown. However, in this configuration, since the mounting board is non-light-transmitting, the arrangement of the light source is restricted, and there is a possibility that sufficient miniaturization cannot be achieved.

On the other hand, in JP-A-62-97370, a light-transmitting sensor substrate on which an optical sensor array is formed is fixed on a light-transmitting mounting board, and a non-transparent resin is placed on the optical sensor. A molded configuration is shown. Information light is received onto the optical sensor via the light-transmitting mounting board and the light-transmitting sensor board, and a light shielding plate is provided on the surface of the light-transmitting mounting board to prevent unnecessary light from entering.

However, in this configuration, the information light from the document surface passes through the translucent mounting board and the translucent sensor board and enters the light receiving element (optical sensor). The arrival path becomes longer, which tends to cause loss of light quantity, and stray light components due to diffused light in each layer are generated, resulting in S
There was a risk that the /N ratio would decrease and the sensor output would decrease.

On the other hand, in a photoelectric conversion device, in particular, as a large number of photoelectric conversion elements are arranged and the wiring pattern becomes longer, the wiring pattern becomes longer, and the structure becomes such that electrical noise is easily mixed in. Sources of this electrical noise include a power supply, static electricity during document transport (when paper is passed), a light source circuit, and the like. This electrical noise induces noise in the signal output circuit, making the image signal unstable. Therefore, as a means to prevent this, there is a method disclosed in Japanese Patent Application Laid-Open No. 63-310261. Here, the base plate (the housing that fixes the sensor) is held at a constant potential to provide a shielding effect against electrical noise. This shielding action prevents electrical noise from entering the sensor and stabilizes the image.

However, this configuration has the following problems.

In other words, when the base plate is set to ground (GND) potential, the static electricity generated when paper is passed through the base plate.

If the base plate is made of a conductive material such as Aj2, it can have a shielding effect, but if it is made of an insulator such as resin, For example, it is difficult to provide a shielding effect.

[Means for Solving the Problems] The present invention aims to solve these problems, and for this purpose, a photoelectric conversion element is provided on the side facing the original for reading image information, and a light-transmitting element is provided. a light source disposed between the support body and the substrate, a light source provided on the side of the support body opposite to the support surface of the substrate; A light shielding part provided in a part other than the optical path part of the light emitted from the light source, the light shielding part being formed using a conductive material and maintained at a constant potential, the light emitted from the light source is supported. The document is characterized in that the light is transmitted through the body, the optical path portion, and the substrate, and is irradiated onto the document, and the reflected light is received by the photoelectric conversion element.

can be done.

[Function] According to the present invention, since the illumination light is transmitted through the translucent mounting board (support body), the degree of freedom in arranging the light source is improved and miniaturization becomes possible. Since the structure is such that the reflected light (reflected light from It also improves. In the present invention, since the illumination light is configured to pass through the board and the mounting board, the illumination light does not have an adverse effect on each sensor due to moderate light loss and diffusion when the illumination light passes through, and the illumination light does not affect the document. Uniform illumination can be achieved.

Furthermore, the light-shielding layer blocks stray light that may cause noise in the output signal, such as diffusely reflected components on the transparent mounting board, out of the illumination light from the light source, thereby improving the resolution of the output signal.

In addition, the light-shielding layer also functions as an electrical shielding layer [Embodiment] The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a cross-sectional view of the vicinity of the end of a photoelectric conversion device according to an embodiment of the present invention. Here, the translucent sensor substrate l is made of a material such as quartz glass or borosilicate glass with translucent and insulating properties. A photosensor array is formed on a substrate using a semiconductor process or the like. The translucent mounting board 2 is made of quartz glass or borosilicate glass.

Thick film printing on a transparent and insulating substrate such as soda glass or acrylic (may be provided with a protective film such as Sin to prevent elution and diffusion of alkali elements) 8g, ^g-Pd, formed by the method
A, g-Pt, ^U, etc., or ^λ formed by photolithography, Cu, Mo, ITO, etc. wiring part 4
have. The bases of these substrates have similar thermal expansion coefficients.

The wiring section 4 connects the sensor section and a drive circuit section (not shown). Then, the light-transmitting sensor substrate 1 is bonded onto the light-transmitting mounting board 2 using the adhesive layer 5. For this adhesive layer 5, a room temperature or heat curing type, light curing, or other transparent adhesive such as silicone, acrylic, or epoxy type is preferably used. A material having a coefficient of thermal expansion similar to that of each of the substrates is used, and can be placed, for example, at both ends of the photoelectric conversion device in the longitudinal direction to bond the substrate 1.2.

Further, the light-transmitting sensor substrate 1 and the wiring portion 4 of the light-transmitting mounting board 2 are electrically connected by wire bonding, soldering, or the like.

Thus, the illumination light from the light source 3 passes through the translucent mounting board 2 and the translucent sensor substrate 1 and is irradiated onto the original 6.
Information light reflected from the original 6 enters the light receiving element on the light-transmitting sensor substrate 1, and is outputted from the light receiving element as an image signal.

According to this example, the information light is transmitted to the mounting board 2 and the sensor board 1.
Since the light is received by the optical sensor without going through the light, there is no loss of light quantity or degradation of the S/N ratio due to stray light components. Furthermore, according to this example, the translucent sensor board 1 and the translucent mounting board 2 can be handled as independent components, that is, they can be manufactured in separate processes, thus unifying the manufacturing process. It becomes possible to use only non-defective products in each separate inspection process, and the overall yield improves. In addition, since only the optical sensor section is arranged on the base of the substrate 1, it is possible to manufacture a large number of substrates 1 at once using a base material having a certain extent, which makes it possible to reduce costs. Furthermore, it is also possible to mount a driving IC chip, an output amplification IC chip, etc. in addition to the wiring section 4 on the transparent mounting board 2, and in that case, further cost reduction becomes possible. Furthermore, by arranging the light source 3 on the back side of the translucent mounting board 2,
The external dimensions of the unit are further reduced.

In other words, according to this embodiment, since the illumination light is transmitted through the light-transmitting mounting board, the degree of freedom in arranging the light source is improved, that is, the light source is placed on the back side of the light-transmitting mounting board. This makes it possible to achieve further miniaturization of the device to which the photoelectric converting wedge device is applied.

In addition, since the information light does not pass through the light-transmitting mounting board or the light-transmitting sensor board, there is no light loss or diffusion of the information light, and the S/N ratio is improved and the sensor output is also good. becomes.

Furthermore, by using a substrate made of a material with a thermal expansion coefficient similar to that of the translucent mounting board and the translucent sensor board, it is possible to alleviate the stress caused by bonding the two, making it difficult for the board to warp or crack. .

In addition, by providing the wiring section on the translucent mounting board, miniaturization of the device is achieved, and by providing the wiring section between the translucent mounting board and the translucent sensor board, further Downsizing is also possible.

FIGS. 2(^) and 2(B) are an exploded perspective view and a cross-sectional view of the main parts of the photoelectric conversion device according to the present example, respectively. In addition, in FIG. 2(^), for example, the adhesive 5 provided near both ends is not shown.

Here, a light shielding layer 7 is provided between the light-transmitting mounting board 2 and the light-transmitting sensor board 1. The light shielding layer 7 is arranged around the slit-shaped window part 7^ that is appropriately defined according to the optical path, and can be formed using the same process and the same metal material as the wiring part 4. It may be formed using a non-transparent and conductive resin by a screen printing method or a dispensing method, or it may be formed using a non-transparent and conductive resin. The light-shielding layer 7 may be formed using a material that is transparent and conductive, and in this case, a separate step of interposing the adhesive 5 is not necessary.

The light-shielding layer 7 created in this way is formed on a portion of the transparent mounting board 2 excluding the optical path of the illumination light, and has a shape having a slit window portion 7^ for light incidence. ,
This slit-like window portion may be left as a void, or may be filled with transparent resin, or a translucent adhesive may be placed here to bond the split substrate 1.2. (See Figure 5), in this case each substrate 1.2 as adhesive.
It is desirable to use a material that has a similar optical refractive index.

In any case, according to the configuration as shown in FIG. 2, in addition to the basic effects described in connection with FIG. For example, by blocking the diffused reflection component on the transparent mounting board 2, the resolution of the output signal can be improved.

Further, as will be described later with reference to FIG. 5, by forming the light shielding layer 7 from a conductive material, it can also function as an electrical shield layer against noise.

FIG. 3 shows a more detailed cross-sectional structure of the photoelectric conversion device according to the embodiment of FIGS. 1 and 2. FIG.

Here, a matrix wiring section 9, an illumination window 10, a light receiving element 11
, a charge storage section (capacitor section) 12, and a switching thin film transistor (TPT) 13 for transferring the accumulated charges at appropriate timing.

Then, the translucent sensor substrate 1'' configured in this manner
is the adhesive layer 5 and/or the light shielding F17 (the optical path part is the window 7A)
) is supported on the translucent mounting board 2. All of these parts can be formed using the same manufacturing process. The layer structure of each part is, for example, C' formed on the substrate, a light-shielding layer lower electrode 15 of the sensor section, an insulating layer of silicon hydrogenated nitride (SINx:H) placed above it, and a hydrogenated silicon layer above it. Amorphous silicon (a-S
It consists of a semiconductor layer of i:H), an ohmic layer of na-5i:H on top of the semiconductor layer, and an upper electrode of 0.degree. C. or the like placed above it.

The optical sensor section having such a configuration has a passivation layer 19.
Further, on this passivation layer 19, a thin plate glass 14 having a thickness of 50μ, for example, is placed on the passivation layer 19 via an adhesive layer 20.
will be provided. The original slides on this thin glass 14, and the thin glass 14 functions as a spacer layer that keeps the distance between the light receiving element 11 and the original 6 constant, and also functions as a wear-resistant layer.

In this configuration, the illumination light irradiated from the back side of the transparent mounting board 2 passes through the transparent mounting board 2 and the transparent sensor board 1, passes through the illumination window IO, and reaches the surface of the thin glass 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 configuration of a photoelectric conversion device having the above basic configuration.

5(A) is a plan view of the sensor unit, FIG. 5(B) is a side view thereof, FIG. 5(C) is a rear view thereof, and FIG. 5([)) is a 0-D ’ cross-sectional view,
(E) is a cross-sectional view taken along line E-E' of the same figure. base plate 2
2 and further press down with the IC cover 23. Next, the light source 3 is fixed to the lower surface of the base plate 22. and,
From the unit, flexible wiring 24 and connector 2
An image signal can be output via 5.

FIGS. 6(^) and 6(B) are diagrams for explaining the function of the light shielding layer 7 made of a conductive material as an electrical shielding layer.

The light shielding layer 7 is made of ^fl, Cr, on the transparent mounting board 2.

As a thin film of Ta, Ti, etc., or as A3. It can be formed from a conductive paste such as carbon, and by maintaining the conductive light shielding layer 7 at a constant potential, it can have a shielding effect. The light source 3 is usually a discharge tube such as an LED or a Xe tube.

EL, fluorescent tubes, etc. can be used, but in the case of discharge tubes in particular, they are driven with high frequency and high voltage, so radiation noise is generated from the five light sources. Even in such a case, the shielding effect according to this example is effective. Note that the reference numeral 26 in the figure indicates that the light shielding layer 7 is GN.
This is a GND line for lowering the potential to D.

According to the configuration of this example, it is possible to obtain an appropriate shielding effect without considering the influence on the base plate during paper passing. In addition, according to the configuration of this example, the material of the base plate does not need to be conductive and may be insulating, so the range of selection of materials for the base plate is expanded, and insulating resin, etc. can also be selected.

Furthermore, the sensor unit 1 configured in this way
00 can be used to configure facsimile machines, image readers, and various other devices.

FIG. 7 shows an example of an image processing device (for example, a facsimile) configured using the sensor unit 100 according to this example.

Here, 102 is a feeding roller for feeding the original 6 toward the reading position, and 104 is a separation piece for reliably separating and feeding the original 6 one by one. A platen roller 106 is provided at a reading position facing the sensor unit 100 to regulate the surface of the original 6 to be read and to convey 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, in the case of a facsimile machine, image information transmitted from the outside is formed. it.

is a recording head for forming the image, and various types such as a thermal head and an inkjet recording head can be used. Further, this recording head may be of a serial type or a line type. 11
A platen roller 2 conveys the recording medium P to a recording position by the recording head 110 and regulates the recording surface thereof.

Reference numeral 120 denotes an operation panel equipped with switches for accepting manual operation, a display section for notifying messages and other device statuses, and the like. Reference numeral 130 denotes a system control board, which is provided with a control section for controlling each section, a processing section for image information of the optical sensor drive circuit section 1, a transmitting/receiving section, and the like. 140 is a power source for the device.

In the embodiments described above, a configuration was described in which the document is read in close contact with or in close proximity to the photoelectric conversion device and the document 6 without interposing an optical system between the photoelectric conversion device and the document 6. The invention can also be effectively applied to a configuration in which light (light) is imaged on a light receiving element via an optical system.

That is, as shown in FIG. 8, even if the configuration uses an optical system member 8 such as a convergent light transmitting body array or a fiber plate between the translucent sensor substrate 1 and the original document 6,
The present invention is easily applicable.

Moreover, although the wiring portion is formed on the transparent mounting board in the upper side, it may be provided on another member. In this case, for example, the wiring may be directly drawn out from the light-transmitting sensor substrate using flexible wiring or the like.

[Effects of the Invention] As explained above, according to the present invention, according to this embodiment, the illumination light is transmitted through the mounting board having translucency, so the degree of freedom in arranging the light source is improved. In other words, it becomes possible to arrange the light source on the back side of the light-transmitting mounting board, 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 light-transmitting mounting board or the light-transmitting sensor board, there is no light loss or diffusion of the information light, and the S/N ratio is improved and the sensor output is also good. becomes.

Furthermore, the light-shielding layer blocks stray light that may cause noise in the output signal, such as diffusely reflected components on the transparent mounting board, out of the illumination light from the light source, thereby improving the resolution of the output signal.

In addition, by forming the light-shielding layer on the translucent mounting board using a conductive material and making it function as an electrical shielding layer, it is possible to prevent static electricity generated when paper is passed from reaching the base plate. Appropriate shielding effects can be provided without considering the effects.

Furthermore, since the base plate may be not only conductive but also insulative, the range of material selection for the base plate is widened.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view near the end of a photoelectric conversion device according to an embodiment of the present invention, and FIGS. 2 (^) and (6) are exploded perspective views of a charging conversion device according to this embodiment, respectively. 3 is a more detailed sectional view of the photoelectric conversion device according to the embodiment of FIGS. 1 and 2 (8) and (B), and FIG. 5 (^), CB), (C) are exploded perspective views showing an example of a sensor unit constructed using the above. ([1) and (E) are respectively plan views of the sensor unit,
The side view, back view, cross-sectional view along the line D-D, cross-sectional view along the line E-E', and FIGS. 6(Δ) and (B) are cross-sectional views for explaining the function of the light-shielding layer as an electrical shielding layer, respectively. FIG. 7 is a cross-sectional view showing an example of an image processing apparatus to which the present invention can be applied. FIG. 8 is a schematic cross-sectional view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Translucent sensor board, 2... Transparent mounting board (support body), 3... Light source, 4... Wiring section, 5... Adhesive layer, 6... Document, 7... Light shielding layer, 78... Window portion, 8... Optical system member, 2-GN [1 line. Figure 2 (A) Figure 2 (B) Figure 6 (A) Figure 8

Claims (1)

[Scope of Claims] 1) A substrate having a light-transmitting property and having a photoelectric conversion element provided on the side facing the original for reading image information; a support supporting the substrate and having a light-transmitting property; , a light source provided on the side of the support opposite to the support surface of the substrate; and a light source provided between the support and the substrate, excluding the optical path portion of the light emitted from the light source. a light shielding part made of a conductive material and held at a constant potential, the light emitted from the light source passing through the support, the optical path part, and the substrate. A photoelectric conversion device characterized in that the reflected light is irradiated onto the document and the reflected light is received by the photoelectric conversion element. 2) The photoelectric conversion device according to claim 1, wherein the light shielding portion is held at a ground potential.