JPS59125073A - Multipoint potential detecting element - Google Patents

Abstract

PURPOSE:To detect simultaneously the potential of plural parts, and to make a detecting element small in size and low in its cost by forming plural pairs of opposed electrodes of a potential detecting side electrode and a ground side electrode, on an electro-optical element, and placing these electrodes so that a distance between the adjacent potential detecting side electrodes attains twice or more comparing with a distance between the opposed electrodes. CONSTITUTION:A light emitted from a fluorescent lamp 8 passes through a polarizer 12 and goes into an electro-optical element 9. 400 pairs of opposed electrodes are formed on the electro-optical element 9 by electrodes 10, 11, and when the surface of a detecting electrode train 18 is opposed in parallel to a linear area to be measured, voltage is applied between each electrode 10, therefore, when a light passes through in the electro-optical element 9 between the electrodes 10, 11, a double refraction is generated in accordance with the applied voltage, and the intensity of a light passing through an analyser 13 on which the polarizer 12 and an optical axis are placed so as to be orthogonal is varied. Its transmission light intensity is detected by a phototransistor of a photodetecting element 14, and the applied voltage is detected by a variation of the intensity of a light before and after transmitting the electro-optical element 9. In this case, when a distance between the adjacent electrodes 10, 10 is set to twice of a distance between the opposed electrodes 10, 11, a crosstalk between the adjacent electrodes 10, 10 can be nearly disregarded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a multi-point potential sensing element that can detect potentials at multiple locations at once.

Conventional Structure and Problems In recent years, with the development of copying machines, there has been a demand for improved image quality. One of the problems in improving image quality is uneven printing. In order to eliminate uneven printing, the potential distribution on the photoreceptor drum of the copying machine must be properly controlled at all times. Therefore, it is necessary to measure the potential distribution on the photoreceptor drum and perform feedback control.

A conventional 18th position detection element will be explained using FIG. 1. (1) is the light source, (2) is the detection side electrode that receives the potential to be measured, (3) is the ground side electrode, (4) is the electro-optical element, (5)
) is a photodetecting element, (6) is a polarizer, and (7) is a polarizer (6
) is an analyzer with a optical axis perpendicular to the optical axis of the Light source (1
) The light incident on the polarizer (6) becomes linearly polarized light,
It enters the electro-optical element (4). The electro-optical element (4) includes:
The sensing side electrode (2) and the grounding side electrode (3) that constitute the counter electrode
), and birefringence occurs due to the potential difference between the respective electrodes (2) and (3), that is, the applied voltage. The amount of birefringence depends on the magnitude of the applied voltage. The birefringent light passes through the analyzer (7) and enters the photodetector (5), but since the analyzer (7) has an optical axis perpendicular to the polarizer (6),
The amount of transmitted light changes depending on the magnitude of the applied voltage. If the detection side electrode (2) is provided close to the part to be measured, for example, the photoconductor drum, the potential on the photoconductor drum will depend on the static voltage formed between the photoconductor drum and the detection side electrode (2). The voltage that is electrostatically divided between the capacitance and the capacitance formed between the sensing side electrode (2) and the grounding side electrode (3) is applied to the electrode (
2) Add during (3). Therefore, by measuring the change in the amount of transmitted light due to this voltage, the potential on the photosensitive drum can be determined. However, with the above configuration, when measuring a wide area such as measuring the potential distribution on the photoreceptor drum of a copying machine, or when measuring multiple locations, a large number of sensing elements are required, making the system expensive and complicated. Not only does this result in a rough structure, but it also has drawbacks such as variations in characteristics.

Furthermore, when a method of scanning along a photosensitive drum using one element is used, there are problems such as a long measurement time and a complicated structure.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and an object of the present invention is to provide a multi-point potential detection confectionery that can detect potentials at multiple locations at once.

Structure of the Invention In order to achieve the above object, a multi-point potential sensing element according to a first invention includes a light source, an electro-optical element into which light from the light source is incident via a polarizer, and a light passing through the electro-optical element. the electro-optical element includes a light detecting element through which the light is incident through an analyzer having an optical axis perpendicular to the optical axis of the polarizer, and the electro-optical element has a pair of light detecting elements perpendicular to the light incident surface and the light exit surface. A plurality of pairs of opposing electrodes including a potential sensing side electrode and a grounding side electrode are formed on the surface, and these electrodes are arranged so that the distance between adjacent potential sensing side electrodes is at least twice the distance between the facing electrodes. The structure is such that position 9 at a plurality of locations can be detected simultaneously by changing the amount of transmitted light according to the tX position difference applied between the opposing electrodes.

Further, a second invention includes a light source, an electro-optical element into which light from the light source is incident via a polarizer, and an optical axis of the light passing through the electro-optical element that is orthogonal to the optical axis of the polarizer. the electro-optical element includes a plurality of pairs of opposing electrodes, each of which is a potential detection side electrode and a ground side electrode, formed on a light incident surface and a light exit surface, respectively. , these electrodes are formed on the input surface and the output surface so that the distance between the potential detection side electrodes formed in the same plane is at least twice the distance between the opposing electrodes. The thickness between the incident surface and the output surface of the electro-optical element is such that the opposite electrode pairs formed in the electro-optical element are arranged in a staggered manner and do not overlap each other when viewed from the direction perpendicular to the incident surface and the output surface. The electrodes are arranged so that the distance between the opposing electrodes is at least twice the distance between the opposing electrodes, and the potentials at a plurality of locations are simultaneously detected by changing the amount of transmitted light according to the potential difference applied between the opposing electrodes. The invention provides a light source, an electro-optical element into which light from the light source enters through a polarizer, and an analyzer in which the light passing through the electro-optical element has an optical axis orthogonal to the optical axis of the polarizer. A ground side electrode is formed on one of a pair of surfaces orthogonal to the light incident surface and the light exit surface of the electro-optical element, and the electro-optic The electric potential distribution of the part to be measured is simultaneously detected by changing the amount of transmitted light according to the potential difference applied to the electro-optical element when the other of the pair of surfaces of the element is opposed to the part to be measured. It is.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 2 is a perspective view of a multi-point potential detection element in an embodiment of the first invention, in which a light source using a fluorescent lamp (Aug. 9) is an electro-optical element; ℃
Hot press fired for 20 hours to make IIE Sitarantan (
Lead zirconate-lead titanate (Pbo,
gg La114z ) (zro, 4 Tio, 6>
0. ((PLZT, 12/40/60)) was used. The various constants of this PLZT sintered body are refractive index n =
2.55, natural birefringence △no ”' 1.148 moi 0, Pockels constant r. = 1.1 x lo
(m/v). OQ (b) is an electrode, and @) is a polarizer and an analyzer, respectively, which are polymeric polarizing films with adhesive and are arranged so that their optical axes are perpendicular to each other.

(b) is a photodetecting element in which phototransistors are arranged in parallel. The electro-optical element (9) and electrode OQ wholesaler are:
90 μm thick (PLZT, 12/40/60
) Aluminum (Al) on both sides of the ceramic substrate! The electrode was deposited to a thickness of about 1 μm, and the thickness was 2 kv/mm at room temperature.
After polarization was performed by applying an electric field of
An electrode pattern with an electrode spacing of 180 μm is processed to form an electrode OQ, and then an 8c
It was cut into a chip of m×90 μm. The electro-optical element (9L electrode OO◇η, polarizer (2), analyzer (
2) is very small and is inconvenient to handle as it is. Therefore, as shown in Fig. 8, a resin plate (C)
was attached with adhesive. At that time, take out the lead wire (A) from the center of each electrode 01, pass it through the hole previously formed in the resin plate (), and connect it to the same shape as the electrode 1 previously formed on the surface of the resin plate (G). Connected to the sensing electrode (G).

Similarly, the lead wire (B) was taken out from the electrode (B) and pulled out to the outside of the resin plate (IQ) through the hole in the resin plate αQ.The electrode Qυ is a ground electrode, and the conductor (B) is grounded. .

Next, the operation will be explained. The light emitted from the fluorescent lamp (8) passes through a polarizer and enters the electro-optical element (9). In the electro-optical element (9), a 400-inch counter electrode is formed by electrodes (11 (b)), and when the surface of the sensing electrode array (to) is opposed parallel to the linear area to be measured, each Since a voltage is applied to the electrode al (11) l[, the electrode (
When light passes through the electro-optical element (9) between 119 and 119, birefringence occurs depending on the applied voltage, and the analyzer (to) is arranged so that the optical axis is orthogonal to the polarizer (b). The intensity of the light that passes through changes. The intensity of the transmitted light is detected by the phototransistor of the light detection element Q4, and the applied voltage is detected by the change in the intensity of the light before and after passing through the electro-optical element (9). Here, by making the distance between adjacent electrodes α191 twice the distance between opposing electrode rings (11), crosstalk between adjacent electrodes 0101 could be almost ignored.

As described above, according to this embodiment, by densely forming a large number of m-poles θQ on the electro-optical element (9), the potential distribution in the linear region can be detected with high resolution.

Next, an embodiment of the second invention will be described. FIG. 4 is a perspective view of an electro-optical element portion provided with electrodes of a multi-point potential detection element in an embodiment of the second invention, in which (11 to 3) are electrodes made of aluminum; ) are connected to each other.Also, electrode α1(1) and electrode )(
E) constitute an electrode pair, and are arranged alternately on the front and back so that they do not overlap when viewed from the direction perpendicular to the element surface. (Foundation) is the same as the embodiment of the invention in ii (
P L Z T , 12/40/60) Electro-optical element cut out from a ceramic substrate, 90 μm x 8 an
It was cut to 90 μm. In addition, the polarization Qi m U) have the same shape, the electrode width is 50 μm, and the adjacent '4
The electrode spacing is 150 μm, the spacing between opposing electrodes is 40 μm, and the surface is '##1. A pole is formed, and the back surface is formed 100 μm from the end. Then, a polarizer and an analyzer (not shown) are attached to the electro-optical element (c) in which the r'pole Q [4] is formed in the same manner as in the first investigation example, and the 11th position is detected. Part (c) is obtained, and as shown in FIG. 5, this is attached to the resin plate (a) with adhesive.

(C) is a lead wire taken out from the electrode shield ◇ on the bottom of the electro-optical element (C), which is pulled out to the outside of the resin plate (B) through a hole formed in the resin plate (), and is grounded. Also(
2) are the lead wires taken out to the electrode 01 of the electro-optical element (c), and these lead wires (d) are placed on the element alternately at intervals of 100 μm from the electrodes Ql (a) on both sides of the electro-optical element (2). The detection electrode formed on the surface of the resin plate (2) is drawn out through the hole at the center of the element in the thickness direction of the element, and then pulled out upward through the hole in the resin plate (2) perpendicularly above the element. attached to the lips. This sensing electrode) is an electrode row in which each electrode is 50 μm x 50 μm and the interval between adjacent electrodes is 50 fim, and a lead wire width (width) is connected to the center of each electrode. Here, when providing electrodes only on one side, adjacent 9JttiTii
II I\LA had to be long enough to ignore crosstalk, and there was a limit to the reduction of electrode width, electrode spacing, etc. due to mechanical precision during processing, so there was a limit to resolution. However, as in this example, crosstalk can be ignored by making the thickness of the front and back surfaces twice the distance between opposing electrodes and providing polarization on both the front and back surfaces.
Twice the resolution can be obtained when electrodes are provided on one side.

In this way, in this embodiment, the potential distribution in the linear region can be measured with high resolution.

Next, an embodiment of the eighth invention will be described. FIG. 6 is a perspective view of the potential detection section in the embodiment of the eighth invention, and shows 0◇
is the same as the embodiment of the first invention (PLZT, 12/40
/60) An electro-optical element cut out from a ceramic substrate, with dimensions of 90 μm x 8 an x 90 μm. (A) is an aluminum electrode in which aluminum is deposited to a thickness of 1 μm on the bottom surface of the electro-optical element 6]. Note that a polarizer and an analyzer (not shown) are attached to the electro-optical element 6◇, as in the embodiment of the first invention. (To)
is the surface of the electro-optical element Op, and the electric potential is detected by making this surface face parallel to the part to be measured. (2) is a resin plate attached to the electrode (to) forming surface of the electro-optical element 09 with an adhesive.

(E) is the lead wire taken out from the electrode 9ψ, and the resin plate ←
It is pulled out to the outside of the resin plate through a hole formed in the resin plate and grounded. Here, in this embodiment, the polarization is only the ground side electrode, and the surface facing it is made to face parallel to the part to be measured, so that the electro-optical element 69
Due to the property of being a dielectric material, an electric charge is generated on the surface of the dielectric material according to the potential distribution of the opposing measurement target part, and a voltage is applied between the dielectric material and the ground electrode (2), and the potential can be detected.

In this way, in this embodiment, the potential distribution in the linear region can be measured continuously without any gaps.

As described in detail, according to the first invention, an excellent effect of detecting potentials at a plurality of locations at once can be obtained. Due to this effect, the potential of multiple locations can be measured with one element, so
The effects of reducing the size of the sensing element, lowering the cost, and shortening the measurement time can be obtained.

Furthermore, according to the invention of @2, it is possible to detect potentials at multiple locations at once with twice the resolution as when electrode pairs are provided on only one side.

Furthermore, according to the eighth invention, it is possible to obtain the effect that the t1 position distribution of the part to be measured can be measured continuously without any gaps.

[Brief explanation of the drawing]

Claims (1)

[Claims] 1. A light source, an electro-optical element into which light from the light source is incident via a polarizer, and an optical axis of the light that has passed through the electro-optical element, which is perpendicular to the optical axis of the polarizer. The electro-optical element includes a pair of surfaces perpendicular to the light incident surface and the light exit surface, and a light detecting element that is incident on the light incident through an analyzer having T.
A plurality of pairs of opposing electrodes including a potential sensing side electrode and a grounding side electrode are formed, and these electrodes are arranged so that the distance between adjacent potential sensing side electrodes is at least twice the distance between the opposing electrodes, and A multi-point potential detection element configured to simultaneously detect potentials at multiple locations by changing the amount of transmitted light according to the potential difference applied between opposing wl poles. 2. A light source, an electro-optical element into which light from the light source is incident via a polarizer, and an analyzer having an optical axis perpendicular to the optical axis of the polarizer, in which the light passing through the electro-optical element is incident. the electro-optical element has a plurality of pairs of opposing electrodes each including a potential detection side electrode and a ground side electrode formed on a light incident surface and a light exit surface, and these electrodes include: The distance between the potential detection side electrodes formed in the same plane is at least twice the distance between the opposing electrodes (and the pair of opposing electrodes formed on the incident surface and the pair of opposing electrodes formed on the exit surface) and do not overlap each other when viewed from the direction perpendicular to the entrance surface and the exit surface, and form a staggered pattern, and the thickness between the entrance surface and the exit surface of the electro-optical element is twice the distance between the opposing electrodes. A multi-point potential detection element configured to simultaneously detect potentials at a plurality of locations by changing the amount of transmitted light according to the potential difference applied between the opposing electrodes by arranging the potentials so that the potential difference is greater than or equal to a value of E.8. A light detection device in which light from a light source enters through an electro-optical element via a polarizer, and light that passes through the electro-optical element enters through an analyzer having an optical axis perpendicular to the optical axis of the polarizer. The electro-optical element includes a ground-side electrode formed on one of a pair of surfaces orthogonal to a light incident surface and an exit surface, and a ground-side electrode is formed on one of the surfaces of the pair of surfaces of the electro-optical element. A detection element that is applied to the electro-optical element when the other surface faces the part to be measured.