JPS63150977A - Semiconductor optical position detector - Google Patents

Abstract

PURPOSE:To detect a position with high reliability by disposing an electromagnetic shielding member on the electrode of a semiconductor optical position detector, thereby preventing an external disturbance from being introduced. CONSTITUTION:A reflecting plate 6, a semiconductor optical position detecting element 1, an electromagnetic shielding plate 7, an optical filter 4 and a liquid crystal panel 3 are sequentially laminated on a liquid crystal drive substrate 20. The plate 7 is formed by laminating a thin aluminum film 7b on a light transmissible flexible film 7a, disposed at positions of the electrodes E1-E4 of the detector, and mounted together with the plate 6. Further, the detector is formed by sequentially laminating a first resistance layer 301, a photoelectric conversion layer 302, and a second resistance layer 303 on an insulating substrate 300, and disposing the electrodes E1, E2 to connect the layer 301 to 4 sides and the electrodes E3, E4 to connect the layer 303. A noise from the panel 3 is removed by the plate 7 to prevent the input of the element 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device detection element, and particularly to a structure for preventing induced noise therein.

[Prior art and its problems]

Drives a light irradiation means such as a light pen using modulated light in an information input section of a computer or multi-function telephone, etc.
A light spot position detection device that enables the input of hand-drawn information and the like by detecting the indicated position using a semiconductor device detection element (PSD) is attracting attention.

It is desirable for the information input unit as described above to display the indicated position of the light irradiation means and its trajectory so that the input information can be viewed visually, and various display devices have been proposed for this purpose.

In one such light spot position display device, a liquid crystal panel is placed on a semiconductor device detection element (PSD), and the light beam from the light pen is input to the optical position detection element, and the indicated position and trajectory are displayed on the liquid crystal panel. There is something like this. (Patent application 6l-
30238) By the way, the optical position detection element is, for example, the fifth
As the cross-sectional structure is shown in the figure, a photoelectric conversion layer such as amorphous silicon and a transparent resistance layer 102 are sequentially laminated on an insulating substrate 100, and first and second layers are further layered on both ends.
electrodes 103 and 104 are disposed, and a photogenerated charge is generated at the light incident position, and this is taken out as a photocurrent from the first and second electrodes.

In this way, the photogenerated charge generated at the light incident position is divided as a photocurrent proportional to the incident energy of the light in inverse proportion to the resistance value, and is extracted from the first and second electrodes. First and second electrodes 103, 104
The distance between L1 and R1 is the resistance, and the distance from the first electrode 104 to the light incident position is Xl, the resistance of that part is R1. 11. When I2, the following equation holds true.

It-1o RL “X, I2-1o”X
RL RL...(1) Here, assuming that the resistance layer 103 is uniform and the length and resistance value are proportional, equation (1) becomes 1, -1, -, I
2-ro Same (-X L L ... (2) From (1) and (2), the current IT taken out to the first and second electrodes,
Similarly, in the case of 02 dimensions in which X can be calculated from 12, calculations can be made for the electrodes taken out from the four electrodes E1 to E4.

Taking advantage of this, in the conventional light spot position display device, as shown in FIG.
The outputs are input to amplifier circuits A1 to A4 each equipped with a variable resistor R for adjustment, and the amplified outputs are input to detection circuits T1 to T4 and A/D converter C1.
~ C4 is input to the CPU 5, where the light incident position by the optical pen is calculated, the liquid crystal panel 3 is driven by the liquid crystal controller 2, and the indicated position is displayed as, for example, a black mark. There is.

By the way, as shown in FIG. 7, such a light spot position display device usually includes a semiconductor device detection probe 1, an optical filter 4, and a liquid crystal drive board 20 including a liquid crystal controller 2.
It has a mounting structure in which liquid crystal panels 3 are sequentially stacked.

In such a structure, since the semiconductor device detection element is only covered with an optical filter, there is a problem in that induced noise from the liquid crystal above or the liquid crystal drive board 20 is input to the semiconductor device detection element. .

This problem occurs not only in the structure in which liquid crystal panels are stacked as described above, but also in cases where there are motors, CRTs, etc. in close proximity, and the induced noise from these becomes a serious problem.

Further, there is a problem in that the light transmitted through the semiconductor device detection element is diffusely reflected by the liquid crystal drive board 20 and enters the semiconductor device detection element again, reducing the position detection accuracy.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to prevent disturbance from being input and to enable highly reliable position detection.

[Means for solving problems]

Therefore, in the present invention, an electromagnetic shielding member is provided on the electrode of the semiconductor device detection element.

Preferably, a reflective member is also provided on the back side of the semiconductor device detection element.

[Effect]

In a semiconductor device detection element, by shielding the electrode, which is the part with the lowest resistance, with an electromagnetic shielding material,
Induction noise input is almost completely blocked.

In addition, by disposing a reflective member on the back side of the semiconductor device detection element, the light transmitted through the semiconductor device detection element can be
The light is accurately reflected by the reflecting member, and resistance to position detection accuracy due to secondary reflected light is prevented.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a structural explanatory diagram of a light spot position display device including a light spot position detection device and a liquid crystal display according to an embodiment of the present invention.

This light spot position detecting device differs from the conventional device shown in FIG. 7 in that a reflecting plate 6 is provided on the back surface of the semiconductor device detecting element 1, and an electromagnetic shielding plate 7 is provided on the electrodes E1 to E4 on the front surface. The other parts are exactly the same as those shown in FIG. 7 (the same members are given the same reference numerals).

That is, a reflection plate 6, a semiconductor device detection element 1, an electromagnetic shielding plate 7, an optical filter 4, and a liquid crystal panel 3 are sequentially stacked on a liquid crystal drive board 20.

Note that the reflecting plate 6 has 1. As shown in the cross-sectional view of FIG. 2(a), an aluminum thin film 6b is used as a film for reflection on an insulating flexible film 6a such as a polyimide film.
It is formed by vapor deposition and is fixed to the back surface of the substrate 300 (see FIGS. 3(a), (b), and (c)) of the semiconductor device detection element with an adhesive or the like during mounting.

Similarly, as shown in FIG. 2(b), the electromagnetic shielding plate 7 is made by laminating an aluminum thin film 7b on a transparent flexible film 7a, and is placed at the positions of the electrodes E1 to E4 of the semiconductor device detection element. They are arranged correspondingly and are installed together with the reflector plate 6.

Furthermore, the semiconductor device detection element is shown in FIGS. 3(a), (b) and (C) (FIG. 3(b) and (c) are respectively
As shown in A-A cross section and B-B cross section in a), a first resistive layer 301, a photoelectric conversion layer 302, and a second resistive layer 303 are sequentially laminated on an insulating substrate 300, Electrodes E1 and E2 are arranged on each of the four sides so as to be connected to the first resistance layer 301, and electrodes E3 and E4 are arranged so as to be connected to the second resistance layer 303. Electric charges are generated, which are taken out as photocurrents from the first to fourth electrodes E1 to E4, and the light incident position is calculated based on the magnitude of these currents.

In this device, noise from the liquid crystal panel 5 is removed by the electromagnetic shielding plate 7, and input to the semiconductor device detection element 1 is prevented.

Further, noise from the liquid crystal drive board is removed by the reflection plate 6.

Furthermore, the light transmitted through the semiconductor light spot position detection element is accurately reflected by the reflection plate 6, and a decrease in position detection accuracy due to secondary reflected light is prevented.

As described above, according to the light spot position display device of the embodiment of the present invention, it is possible to prevent disturbances from entering the position detection element and perform highly reliable position detection, so that the input image information can be displayed on the liquid crystal panel. can be displayed with high precision.

In addition, in the embodiment, a light spot position display device in which a liquid crystal panel and a semiconductor device detection element are stacked is described.
Even when a semiconductor device detection element is used alone, the present invention is effective in preventing the influence of disturbance and performing accurate position detection.

Further, although a reflecting plate is disposed on the back surface of the semiconductor device detection element and the electrode is covered with a shield member, it goes without saying that either one of them is also effective.

Furthermore, in the embodiment, the reflector and the shield member were mounted separately, but for example, as shown in FIGS. 3(a), (b), and (c)
As shown in FIG. 4(a), a reflective film 3 made of a thin aluminum film is applied to the electrode surface of a semiconductor device detection element as shown in FIG.
05 may be formed into a film and the electromagnetic shielding member may be integrally formed. Also, regarding the reflective member on the back side,
The reflective film 305 may be formed directly on the back surface of the substrate. In this case, if a highly translucent material is selected for the insulating film, the entire surface may be covered and only the aluminum thin film 305' may be patterned, as shown in FIG. 4(b). . Furthermore, an insulating film 30 used on the surface side
It is also possible to form the filter 4' with a dyeable resin film and give it a function as an optical filter.

〔Effect of the invention〕

As described above, according to the present invention, since the electrode surface of the semiconductor device detection element is covered with the electromagnetic shielding member, it is possible to remove disturbance noise and detect a stable position signal.

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory diagram of a light spot position display device according to an embodiment of the present invention, FIG. 2(a) is a sectional view of a reflector of the device, and FIG. 2(b) is an electromagnetic shield of the device. Figure showing the board, Figure 3 (
a), (b), and (c) are views showing the semiconductor device detection element of the same device (Fig. 3 (b) and (c) are the A-A cross section and B-B cross section of Fig. 3 (a), respectively). Figures 4(a) and 4(b) are diagrams showing other embodiments of the present invention, Figure 5 is an explanatory diagram of the structure of a semiconductor device detection element, and Figure 6 is a diagram showing a structure using a liquid crystal. A block diagram of a light spot position display device, FIG. 7 is an explanatory diagram of the implementation of a conventional light spot position display device. 100... Substrate, 101... Photoelectric conversion layer, 102...
...Resistance layer, 103...First electrode, 104...Second electrode, E1-E4...Electrode, Rv...Variable resistance, A1 (~A4)...Amplification circuit, TI (~T4)...
・Detection circuit, CI (~C4)...A/D converter, 1.
...Semiconductor device detection element, 2...Liquid crystal controller,
3...Liquid crystal panel, 4...Optical filter, 20...
・Liquid crystal drive board, 6...Reflector, 7...Electromagnetic shield plate, 6a...Flexible film, 6b...
- Aluminum thin film, 7a... Flexible film, 7b... Aluminum thin film, 300... Substrate, 3
01... First resistance layer, 302... Photoelectric conversion layer, 3
03... Second resistance layer, 304... Insulating film, 305
...reflective film. Figure 1 Figure 2 (b) Figure 3 (0) Figure 3 (b) Figure 3 (C) Figure 4 ((1) Figure 4 (b) Input Figure 5 Figure 7

Claims (1)

[Scope of Claims] (1) A photoelectric conversion layer and a resistive layer are laminated on a substrate, and photogenerated charges generated in the photoelectric converting layer at a light incident position are transferred onto the resistive layer via the resistive layer. 1. A semiconductor optical position detection element configured to detect a light incident position by being taken out from an electrode disposed on the semiconductor optical position detection element, characterized in that an electromagnetic shielding member is disposed on the surface of the electrode. (2) The semiconductor optical position detection element according to claim (1), wherein the electromagnetic shielding member is made of a conductive layer formed on the electrode with an insulating layer interposed therebetween. (3) The semiconductor device detection element according to claim (2), wherein the insulating layer is a filter layer formed on the entire surface of the resistance layer.