JPH085567Y2 - Photo sensor element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a photosensor device, and more particularly to a photosensor device using an amorphous silicon semiconductor.

[Conventional technology]

Conventionally, a photo sensor element for detecting an object to be detected by stacking a transparent electrode, a semiconductor layer, and a metal electrode on a translucent insulating substrate made of glass or a hard synthetic resin and utilizing the electric current generated by the semiconductor layer has been conventionally used. Exists more.

However, in such a photo sensor element, since a single crystal silicon, polycrystalline silicon or other crystalline semiconductor layer is used as a semiconductor layer, an element having an arbitrary shape according to the application can be obtained. It was difficult and costly.

For example, when detecting the surface condition of the object to be detected,
The surface of the object to be detected is irradiated with light from a light emitting diode using a SELFOC lens or the like, and the reflected light is received by a photo sensor element.

At this time, the white part of the surface of the object to be detected reflects a large amount of light, and the black part absorbs the light.Therefore, the current generated in the sensor part corresponding to the white part is large and that generated in the sensor part corresponding to the black part. Since the applied current becomes small, the state of the surface of the object to be detected can be known by measuring this current.

[Problems to be solved by the device]

In such a photo sensor element, since it is necessary to irradiate the light emitting diode from a position oblique to the lateral direction of the sensor element, it is difficult to uniformly irradiate the photo sensor element formed on the insulating substrate with light. Yes, high detection accuracy could not be expected.

In particular, when the photosensor element is divided to form a plurality of sensor parts, the amount of light received by each sensor part varies, resulting in a large detection error. When a plurality of light emitting diodes are used, it is difficult to keep the light amount of each light emitting diode constant, and therefore accurate detection cannot be expected.

[Means for solving the problem]

In view of the above problems, the present invention provides a transparent window on a transparent insulating substrate, which is a non-laminated portion where only the insulating substrate is not laminated with other opaque members and which is transparent around the transparent window. A photosensor element having a plurality of sensor portions in which an electrode, an amorphous silicon semiconductor layer, and a metal electrode are sequentially laminated, wherein the photosensor element has a square shape, and one side is one side of the photosensor element. Of four substantially square-shaped sensor portions each having a length equal to or less than half the length of the photosensor element are formed in a positional relationship corresponding to the coded region in the square-shaped detection pattern, and the center of the photosensor element is formed. A circular light-transmitting window is disposed at the position, and the shape of the light-transmitting window is formed by the metal electrode, which constitutes a photosensor element.

At this time, the transparent electrodes of the sensor unit located around the transparent window can be shared, and the metal electrodes of the sensor unit located around the transparent window can be shared. A photosensor element having a plurality of sensor portions in which an electrode, an amorphous silicon semiconductor layer, and a metal electrode are sequentially laminated, wherein the photosensor element is formed in a square shape, and one side of the photosensor element is formed. Four substantially square sensor portions each having a length equal to or less than half the length of one side are formed in a positional relationship corresponding to the coded region in the square detection pattern, and A photosensor element is formed by arranging a circular light-transmitting window at the center, and forming a cross-shaped laminated portion formed by metal electrodes in a plan view in the light-transmitting window.

[Action]

The photo sensor element according to the present invention is configured as described above, and the photo sensor element is positioned on an object to be detected,
The object to be detected is detected by irradiating light from a light emitting diode or the like from the back surface of the light-transmitting window and measuring the current generated by the sensor element that receives the reflected light from the object to be detected.

At this time, one of the transparent electrode and the metal electrode is used as a common electrode, and the current of the other electrode which is made independent can be measured to easily detect the object to be detected.

For example, in the case where the photo sensor element is formed in a square shape in a plan view and four substantially square sensor portions each having a length equal to or less than half the length of one side of the photo sensor element are formed, This is used when reading code information in which a set of four parts corresponding to four sensor parts is set.

〔Example〕

 The details of the present invention will be described based on illustrated embodiments.

1 to 3 are explanatory views of a manufacturing process of an embodiment of a photo sensor element according to the present invention, and FIG. 4 is AA in FIG.
FIG.

In the figure, reference numeral 1 is a translucent insulating substrate made of glass, hard synthetic resin or the like.

Reference numeral 2 denotes a transparent electrode made of indium-tin oxide (hereinafter referred to as ITO) or tin dioxide (hereinafter referred to as SnO ₂ ) or the like, which is formed to a thickness of 300Å to 1000Å.

The transparent electrode 2 is formed in a shape corresponding to one or a plurality of sensor portions to be formed on the insulating substrate 1. In the illustrated example, the transparent electrode 2 is a circular non-laminated portion in the center. Along with forming the window 3, the window 3 is divided so as to correspond to the four sensor portions 6, and the electrode lead-out portion 9 is formed corresponding to each sensor portion 6.

Reference numeral 4 denotes an amorphous silicon type semiconductor layer laminated by a glow discharge decomposition method. This is, for example, a PIN in which p type amorphous silicon carbide, i type amorphous silicon and n type amorphous silicon are laminated from the light receiving surface side.
A heterojunction type amorphous silicon semiconductor layer or the like is used and has a thickness of about 1 μm, and is also divided into shapes corresponding to the four sensor portions 6.

For the amorphous silicon-based semiconductor layer 4, it is also possible to use a pn junction type amorphous silicon-based semiconductor. In addition to this, one containing amorphous silicon-germanium,
It includes those containing microcrystalline materials such as amorphous silicon, amorphous silicon carbide, and amorphous silicon germanium.

5 is a metal electrode, and this metal electrode 5 contains a metal component selected from chromium, nickel, titanium, aluminum, etc.
It is formed by an EB vapor deposition method or the like, and is preferably formed with a thickness of 1000 Å or more.

Here, the shape of the metal electrode 5 is formed by photo-etching or the like, and the edge located at the center forms the light-transmitting window 3. In the example shown in FIG. In this way, four sensor units 6 are formed.

It is also possible to stack a polymer protective film such as an epoxy resin or a phenol resin on the metal electrode 5.

As shown in the side view for explanation in FIG. 5, the photo sensor element thus constructed has a translucent, insulating substrate 1 and an object 7 to be detected.
The light from the light emitting diode 8 and the like is radiated from the rear surface to the light transmitting window 3 from the rear side.

The radiated light passes through the transparent window 3, is reflected by the surface of the object 7 to be detected, passes through the transparent insulating substrate 1 again, and the sensor portion 6
Incident on.

At this time, a large amount of light is reflected on the white portion of the surface of the object to be detected 7 and the light is absorbed on the black portion. Therefore, the sensor portion 6 located in the white portion produces a large current, and the sensor portion located in the black portion is large. In 6, the generated current is small.

Therefore, the metal electrode 5 is connected to one as a common electrode,
Electrode lead-out portion 9 of transparent electrode 2 corresponding to each sensor portion 6
By measuring the current of, the state of the surface of the detected object 7 can be detected corresponding to each sensor unit 6.

As the one to be detected in the embodiment according to the present invention, a coded information is used.
It can be used to detect a code signal as shown. The pattern shown in FIG. 6 is a detection pattern in the shape of a square, and the information is represented by the difference in the black and white coloring patterns in the four divided areas of the square, that is, the coded area.

That is, the code signal identified as the color-coded pattern of the coded area corresponds to the binary code of four coded areas formed by dividing a square into four, and the black-painted portion is detected. By this, the coded information can be read.

A photo sensor element is formed corresponding to the size of the code written on the surface of the object to be detected 7, and the light emitting diode 8 is located at the light transmitting window 3 from the back surface of the photo sensor element.
Of the four sensor portions 6 located in the black-painted portion of the code has a small current to be emitted, and the sensor portion located in the white portion has a large generated current. If this current is measured, the code written on the surface of the detected object 7 can be easily detected.

At this time, since the transparent window 3 is formed by the edge of the metal electrode 5 formed by photo-etching or the like, its shape can be formed with an error of ± 10 μm or less, and the light-transmitting window 3 is formed with high accuracy. It is possible.

As a result, the light of the light emitting diode 8 can be evenly transmitted through the light-transmissive window according to each sensor unit 6, and the surface of the object 7 to be detected can be evenly illuminated, and the detection accuracy of each sensor unit 6 can be improved. It is possible to improve.

Further, as the light source, one light emitting diode 8 can be used to perform detection by the four sensor units 6, so that the amount of light received by each sensor unit 6 can be kept constant, and the S / N The ratio can be improved.

Since the amorphous silicon semiconductor layer is used as the sensor element, it is easy to form a sensor portion having an arbitrary shape, and the transparent window 3 may be formed in the center as in the embodiment. It can be done easily.

Further, since the amorphous silicon semiconductor layer is used,
As compared with a crystalline semiconductor layer, it has a better reaction to light, particularly in the visible light range, so that it is possible to provide a photosensor element with high detection accuracy.

7 to 9 are plan views for explaining the manufacturing process of the second embodiment of the photosensor element according to the present invention.

That is, on the transparent insulating substrate 1 made of glass or the like, a transparent electrode 2 made of ITO or SnO ₂ or the like, an amorphous silicon-based semiconductor layer 4 and chromium, nickel, titanium, a metal electrode 5 made of aluminum or the like stacked Thus, the four sensor portions 6 are formed, and the non-laminated portion in which the other opaque member is not laminated on the insulating substrate 1 at the center is used as the transparent window 3.

While the metal electrode 5 is used as the common electrode in the first embodiment, the transparent electrode 2 is used as the common electrode in the second embodiment, and the portion located between the adjacent sensor portions 6 of the transparent electrode 2 is the electrode. The take-out portion 9 is used as the common electrode 1
It is what is connected to one.

Further, an electrode lead-out portion 10 is formed on the metal electrode 5 so as to correspond to each sensor portion 6.

The second embodiment of the photo sensor device according to the present invention as described above
In the embodiment, since the transparent electrode 2 is common, the state of the surface of the object 7 to be detected is detected by each sensor unit 6 by measuring the current of the electrode lead-out unit 10 of the independent metal electrode 5. It can be detected correspondingly.

Also in the second embodiment, it is possible to correspond to the code shown in FIG.

FIG. 10 is a plan view for explaining the third embodiment of the photo sensor element according to the present invention.

That is, the transparent electrode 2, the amorphous silicon semiconductor layer 4 and the metal electrode 5 are sequentially laminated on the translucent insulating substrate 1 made of glass or the like to form a photosensor element having a square shape in plan view, and one side is Four substantially square sensor portions 6 each having a length equal to or less than half the length of one side of the photo sensor element are formed, and a circular light transmitting window 3 is formed at the center of the photo sensor element. So that the sensor portion 6 is cut out and the metal electrode 5 is provided inside the light-transmissive window 3 so as to have a cross shape in plan view.
11 are formed.

The laminated portion 11 can be formed at the same time when the metal electrode 5 is formed, and includes a central circular portion 12 and partition portions 13 extending from the circular portion 12 in all directions.

The laminated portion 11 is not limited to the illustrated shape, and may be any portion that divides the light-transmitting window 3 into equal parts according to the sensor 6.

In the third embodiment of the present invention thus configured, the translucent window 3
However, since it is divided into a shape corresponding to the sensor portion 6 by the laminated portion 11 of the metal electrode 5 and the transmitted light near the boundary of the sensor portion 6 can be cut, the detection error between the adjacent sensor portions 6 is reduced. Therefore, the S / N ratio can be improved. Therefore, the code signal shown in FIG. 6 can be accurately detected.

Further, since the light amount is strong in the central portion of the light emitting diode, the light varies, but the laminated portion of the metal electrode 5
Since the circular portion 12 corresponding to the cross portion of the cross is formed at the center of 11, the light in the central portion of the light emitting diode can be cut and the irradiation light in the transparent window 3 can be made uniform. It is possible.

[Effect of device]

The photosensor element according to the present invention has the above-described configuration, and since the sensor element is formed by using the amorphous silicon semiconductor layer, it is possible to configure the sensor section of any shape. For example, a sensor in which a photosensor element formed in a square shape is divided into four to form four sensor portions and a light-transmitting window is formed at the center so that light from a light-emitting diode is emitted from the back surface. Can be used to read the code information corresponding to the above.

Further, since the metal electrode provided on the back surface of the semiconductor layer is formed by photo-etching, the obtained shape has high accuracy, and the translucent window corresponding to each sensor section can be formed uniformly.

As a result, the light transmitted through the light-transmissive window can be kept uniform according to each sensor unit, the detection error of the sensor unit can be reduced, and the S / N ratio can be improved.

Further, by forming a laminated portion having a cross shape in plan view formed by the protective film in the light-transmitting window, it is possible to cut the transmitted light in the vicinity of the boundary between the sensor portions, and reduce the detection error between adjacent sensor portions. It is possible to improve the S / N ratio. Further, since the light corresponding to the intersection of the crosses cuts off the light in the central portion of the light emitting diode, it is possible to make the irradiation light in the light transmitting window uniform. Therefore, a highly accurate photo sensor element can be realized.

[Brief description of drawings]

1 to 3 show a first embodiment of a photo sensor device according to the present invention.
A plan view for explaining a manufacturing process of an embodiment, FIG. 4 is a first view of the present invention.
FIG. 5 is a sectional view for explaining an embodiment, FIG. 5 is a side view for explaining the first embodiment of the present invention, and FIG. 6 is an explanatory view showing an example of a code detected by a photosensor element according to the present invention. ~
FIG. 9 is a plan view for explaining the manufacturing process of the second embodiment of the photosensor element of the present invention, and FIG. 10 is a plan view for explaining the third embodiment of the photosensor element of the present invention. 1: translucent insulating substrate, 2: transparent electrode, 3: translucent window, 4: semiconductor layer, 5: metal electrode, 6: sensor part, 7: object to be detected, 8: light emitting diode, 9: electrode extraction part , 10: electrode extraction part, 11: laminated part, 12: circular part, 13: partition part.

Claims (4)

[Scope of utility model registration request] 1. A non-laminated portion, which is formed only on the transparent insulating substrate and on which no other opaque member is laminated, as a transparent window on the transparent insulating substrate.
A photosensor element having a plurality of sensor portions in which a transparent electrode, an amorphous silicon semiconductor layer, and a metal electrode are sequentially laminated around the transparent window, wherein the photosensor element has a square shape, and Four sensor portions each having a substantially square shape whose one side has a length equal to or less than half the length of one side of the photosensor element are formed in a positional relationship corresponding to a coded region in the square pattern to be detected. At the same time, a circular light-transmitting window is provided at the center of the photosensor element, and the shape of the light-transmitting window is formed by the metal electrode. 2. A photosensor element according to claim 1, wherein the transparent electrodes of the sensor portion located around the transparent window are commonly used. 3. The photosensor element according to claim 1, wherein the metal electrodes of the sensor portion located around the light-transmitting window are commonly used. 4. A photosensor element comprising a transparent insulating substrate, and a plurality of sensor portions in which a transparent electrode, an amorphous silicon semiconductor layer, and a metal electrode are sequentially laminated on the translucent insulating substrate. Four substantially square sensor portions each having a square shape and one side having a length equal to or less than half the length of one side of the photosensor element are provided in a coded area in the square detection pattern. In addition to being formed in a corresponding positional relationship, a circular light-transmitting window is disposed at the center of the photosensor element, and a laminated portion having a cross shape in plan view formed of metal electrodes is formed in the light-transmitting window. A photo sensor element formed by.