JPH01187985A - Optical potentiometer - Google Patents

Abstract

PURPOSE:To compensate errors resulting from the nonuniformity of resistance films and a photoconductive film, and to improve the linearity of potential distribution characteristics and output voltage characteristics by forming a pair of electrode films onto the photoconductive film formed onto the same substrate and two or more of the resistance films between the electrode films and mutually short-circuiting several positions at the same potential of the resistance films. CONSTITUTION:A pair of first and second electrode films 13a, 13b are formed onto a photoconductive film 12 shaped onto the same substrate 15 and two or more of resistance films 11a, 11b between the electrode films 13a, 13b. Said first and second electrode films 13a, 13b are connected to an external terminal T13, two or more of said resistance films 11a, 11b are connected in parallel, and one ends of the resistance films 11a, 11b are connected to an external terminal T11, and the other ends are connected to an external terminal T12. Several positions at the same potential of said first and second resistance films 11a, 11b are short-circuited mutually by metallic wires or metallic films 17. Accordingly, the nonuniformity of the sheet resistance distribution, etc., of one resistance film is compensated by the sheet resistance distribution, etc., of the other resistance film, thus improving the linearity of potential distribution characteristics.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to an optical potentiometer, particularly an optical potentiometer that converts non-contact position or angular displacement into a voltage value. In order to correct errors caused by uniformity and improve the linearity of potential distribution characteristics and output voltage characteristics, a pair of first and second photoconductive films are formed on the same substrate.
and two or more resistive films between the electrode films, the first and second electrode films are connected to an external terminal, the two or more resistive films are connected in parallel, and One end of the resistive film is connected to an external terminal, the other end is connected to an external terminal, and several positions of the first and second resistive films having the same potential are mutually short-circuited by a metal wire or a metal film. It consists of the following:

[Industrial Application Field] The present invention relates to an optical potentiometer, and more specifically, to a one-piece optical potentiometer that linearly converts a non-contact position or angular displacement into a voltage value.

(Conventional technology) FIG. 5.6 is an explanatory diagram of a conventional example.

5(a) to 5(c) are structural diagrams of a conventional optical potentiometer, and FIG. 5(a) shows a plan view thereof.

In the figure, 1 is a resistive film such as NiCr film or Cr-5iO11Q, and 2 is a photoconductive film 13 such as CdSc film or Cd (SeS) film, which is Cr-Au lp3 or NiCr-
An electrode film such as an Au film, and 6 a spot light.

In addition, in FIG. 0, which is a cross-sectional view taken along the X-Y arrow in FIG. It is made of resin or the like. 5 is a substrate such as a glass plate or an alumina plate.

Figure (C) is an equivalent circuit diagram of an optical potentiometer.
In the figure, R is a resistor, T and T3 are external terminals, and L is the total length of the resistor R, which is, for example, about 10 (nm). Note that S is a position where the light guide TL film 2 between the resistive film 1 and the electrode film 3 is irradiated with the spotlight 6 over its entire length. Further, 6 is a spot light having a width of about 2 [an], and the light source and a mask of a light spot irradiation rotation device etc. cause the resistive film 1 to move at the position S, for example, according to electrical and mechanical positional displacement and angular displacement. The photoconductive film 2 and the electrode film 3 are electrically connected to each other.

These constitute an optical potentiometer, and its function is to convert electrical and mechanical positional and angular displacements into voltage values via light 6, thereby detecting positional and angular displacements without contact. That's true.

No. GIA is a diagram illustrating the problems of a conventional optical potentiometer, and FIG. 3A shows a potentiometer circuit diagram.

In the figure, ■. is the T of the optical potentiometer.

, the electric voltage (e.g. DC voltage) applied between T2, V
(s) is the voltage between T, , T, and is the potential difference at position S.

FIG. 5B is a potential distribution characteristic diagram of the optical potentiometer. In the figure, the vertical axis is 1! Source voltage ■. and potential difference V (
s), and the horizontal axis indicates the position S.

Further, 7 shown as a solid line is an actual potential distribution characteristic. For example, since the resistive film 1 includes a defective portion 9, the distribution of the resistance R becomes non-uniform and does not form a perfect straight line. Note that 8 indicates an ideal potential distribution characteristic. In addition, the defective part 9 is
Due to the non-uniform thinning of the resistive film 1 in the film forming technology, these do not occur at the same time in the same place stochastically.

(Problems to be Solved by the Invention) According to the conventional example, an optical potentiometer having a defective portion 9 in the resistive film 1 as shown in the actual potential distribution line 7 shown in FIG. It is used as a mechanical position and angle detector.

However, with the current film forming technology for the resistive film 1, the uniformity of the sheet resistance value is limited to approximately ±0.5%. Further, the non-uniformity of the photoconductive film 2 is remarkable in a range where the output voltage of the optical potentiometer is small.

Therefore, there are the following problems.

(2) Since the actual potential distribution characteristic 7 showing the relationship between the output voltage and the contact surface is not a perfect linear characteristic (currently 11% is the limit), an error occurs between the true position and its output voltage.

■Depending on the detection position range due to the non-uniformity of the photoconductive film 2,
The output voltage includes an error.

The present invention was created in response to the problems of the conventional example, and corrects errors caused by non-uniformity of resistive films and photoconductive films, and improves potential distribution characteristics and output voltage characteristics. The object of the present invention is to provide an optical potentiometer that can improve linearity.

[Means for Solving the Problems] The optical potentiometer of the present invention has an embodiment as shown in the first to
As shown in FIG. 4, on the photoconductive film 12 provided on the same substrate 15, a pair of first and second electrode films 13a and 13b,
two or more resistive films 11a between the electrode films 13a and 13b,
11b, the first and second electrode films 13a and 13
b is connected to the external terminal T+3, the two or more resistors Wi11a, 11b are connected in parallel, and one end of the resistive film 11a, 11b is connected to the external terminal T1.
1, and the other end is connected to external terminal TI! The above object is achieved by connecting several positions of the first and second resistive films +1a and 11b that are at the same potential to be mutually short-circuited by a metal wire or a metal film 17.

[Effect]

According to the present invention, two or more resistive films are connected in parallel, and several positions of the resistive films having the same potential are short-circuited to each other by a metal wire or a metal film. Therefore, it is possible to correct the non-uniformity of the sheet resistance distribution, etc. of one resistive film by tJ by the sheet resistance distribution, etc. of the other resistive film.

This makes it possible to improve the linearity of potential distribution characteristics.

Further, according to the present invention, a third resistor for potential distribution correction is provided between the first and second resistive films. For this reason, 1.
It becomes possible to mutually correct the non-uniformity of the sheet resistance distribution, etc. of the second resistive film, and further correct it by the sheet resistance distribution, etc. of the third resistive film.

This makes it possible to further improve the linearity of the potential distribution characteristics.

[Example] Next, an example of the present invention will be described with reference to V.

1 to 4 are explanatory diagrams of an optical potentiometer according to an embodiment of the present invention, and FIG. 1 shows an eight diagram of the structure of an optical potentiometer according to a first embodiment of the present invention.

FIG. 2A is a plan view of the optical potentiometer. In the figure, 11a and 11b are resistive films such as NiCr17 or Cr-3iO1i provided on the photoconductor 11'212. In addition, the sea 1-1 degree l redundancy of the 1 degree resistive films 11a and 11b is approximately 30.0Ω/mouth, and in the embodiment of the present invention, the 1 degree I redundancy (direction R1 or 800
It is about [Ω] to 1.5 (KΩ).

Also, the resistance is 1f! J11a and J11b are connected in parallel, one of which is electrically connected to external terminal T11, and the other is similarly connected to external terminal T, □.

Note that 17 is a thin metal film or metal wire that short-circuits the same potential parts of the resistive films 11a and 11b.

Reference numeral 12 is a photoconductive film such as a CdSe film or a Cd (SeS) film, and a certain amount of paper CdSe, CdS powder, etc. is deposited under a predetermined atmosphere (for example, Cd
Cff.

It is formed by heat treatment (for example, at about 550°C) in a gas).

13a, 13b are I:, r-Au Ft or NiCr
- It is an electrode film such as a U film. Note that the electrode film 13a, L3
One of the terminals b is electrically connected to the external terminal Tlj.

Further, the electrode films 13a and 13b and the resistive film 11a.

11b is the photoconductive film 12 while keeping a certain distance constant.
is installed on top.

Reference numeral 16 denotes a spot light having a width of about 2 [proof], and is formed by a light source such as a mini chair lamp (not shown) and a mask such as a light spotting device, a u+ rotation device, etc. Note that the light 16 is applied to the resistive film 1 according to electrical and numerical positional displacements and angular displacements.
Photoconductivity 112 between 1a, 11b and electrode films 13a, 13b
12, thereby making the photoconductive m12 electrically conductive.

Further, FIG. 3B is a cross-sectional view taken along the line X-Y in FIG.

1, a photoconductive film 12 such as a Cd(ScS):Cu vapor deposited film is heat-treated at about 550° C. for 170 minutes using CdCl2 on a substrate 15 made of glass, alumina, ceranomink, or the like. Next, electrode films 13a and 13b such as old Cr-Cu film are formed on the photoconductive film 12, and the same potential portion is connected with a thin metal wire 1.
7, etc., and a transparent protective layer 14 is formed on the entire surface for insulation.

Note that the transparent protective film 14 covers the resistive films 11a and 11b and the electrodes v.
13a,] 13b, and transmits light 16, such as silicone resin.

FIG. 2C is an equivalent circuit diagram of the optical potentiometer according to the first embodiment of the present invention. In the figure, R is the resistance 11
The resistors 911a and 11b, T l l to T I 'l are external terminals, and L is the total length of the resistor R, which is 10 (mm) in the embodiment of the present invention. Note that S is the position, and the spot light 16 is located between the entire WL and between the resistor 1fC films 11a, 11b and the TL poles v, 13a, 13b.
This is the position where the beam is irradiated.

In addition, in the equivalent circuit diagram, the part indicated by the arrow is the spot light 16.
is a conductive portion resulting from irradiation of the photoconductive film 12. Therefore, the light 16 has the function of a slider of a sliding resistor. Incidentally, when the spot light 16 is not irradiated, the conductive portion corresponding to the slider disappears, and the central portion in the equivalent circuit diagram also disappears.

These constitute the optical potentiometer according to the first embodiment.

FIG. 2 is an explanatory diagram of potential distribution characteristics according to the first embodiment of the present invention, and FIG. 2(a) shows a potentiometer circuit diagram.

In the figure, ■. is the optical potentiometer T1. .

Applied between 712? Ha voltage (e.g. DC voltage),
Similarly, V (s) is the voltage between T 1gl and Tl1, and is the potential difference at the position S.

FIG. 5B is a potential distribution characteristic diagram of the optical potentiometer. In the figure, the vertical axis represents the potential distribution V (s)/V, and the horizontal axis represents the position S.

Note that 18 shown by the broken line is an ideal potential distribution characteristic, where the potential distribution V(s)/Vo and the position S change linearly (in terms of − order numbers), and the error is completely (does not include). A1 shown by the solid line is the potential distribution characteristic of the resistive film 11a, and one is a defective portion of the characteristic A1 characterized by non-uniformity of the sheet resistance distribution of the resistive film 11a.

Further, B indicated by the - dotted chain line is the potential distribution characteristic of the resistive film 11b, and 20 is a defective part of characteristic B1, which is similarly characterized by non-uniformity in sheet resistance distribution, etc. of the resistive film 11b. It is.

Note that 21 indicated by the two-dot chain line is a composite potential distribution characteristic obtained by combining the potential distribution characteristic A1 and the potential distribution characteristic B1.

This allows the photoconductive I+! ;! If characteristic 12 is ignored, defective portion 19 of characteristic A is corrected by potential distribution characteristic B1, and defective portion 20 of characteristic B is corrected by potential distribution characteristic A.
, the measurement error can be suppressed.

FIG. 3 is an explanatory diagram of the output voltage distribution characteristics according to the first embodiment of the present invention, and FIG. 3(a) shows a potentiometer circuit diagram taking into account the bright resistance of the photo-IS electrical film 12.

In the figure, r,, rb are the bright resistances (parasitic resistances) that occur when the photoconductor 1'l' 212 is irradiated with light, and depending on the position S, it becomes non-uniform in the same 1r as the resistive films 11a, 11+). ing. Further, Ve (s) is the output voltage appearing at the external terminals Tlz and TI□ of the optical voltimeter. Note that Vo is the external terminal T11. This is the DC voltage applied to T1□.

FIG. 5B shows an output voltage distribution characteristic diagram of the optical potentiometer according to the first embodiment of the present invention. In the figure, the vertical axis is the output voltage distribution V, (s) /Vo, which is 4M
The axis shows the position Is.

Moreover, 22 shown by the broken line is the resistive film 11. 1.a and 1.1b show potential distribution characteristics of an ideal resistive film without non-uniformity.

Note that A2 shown as a solid line is the output voltage distribution characteristic considering the bright resistance of the photoconductive film 12, and B2 similarly shown as a dot-dashed line is the output voltage obtained by taking the bright resistance of the photoconductive film 12 into consideration. It is a distribution characteristic.

Further, 23 indicated by the two-dot chain line is a composite output distribution characteristic obtained by combining the output voltage distribution characteristic Δ2 and the output voltage distribution characteristic B2.

As a result, if the potential distribution characteristics of the resistive films 11a and 11b are ignored, the nonuniformity of the photoconductive TL film 12 having the characteristic A2 is corrected by the output voltage distribution characteristic B2, and the photoconductive film 12 having the characteristic B
By correcting the non-uniformity of the output voltage distribution characteristic A2, it is possible to suppress measurement errors such as position and angular displacement.

FIG. 4 is a structural diagram of an optical potentiometer according to a second embodiment of the present invention, and FIG. 4(a) shows a plan view thereof.

Note that the difference from the first embodiment is that the first and second resistive films 3
The third resistive film 31c is provided between 1a and 131b.

In the figure, 131a and 131b are a resistive film 132 and a photoconductive film 133a and 133b are a pair of electrode films, as in the first embodiment.

Note that 131c is a potential distribution correction resistor n for correcting the potential distribution of the resistor 11231a131b. In addition, the resistive films 31a and 131b and the resistor F! for potential distribution correction are also included. 31
C is connected in parallel, one of which is electrically connected to the external terminal Tel, and the other is similarly connected to the external terminal T22. Note that 137 is the resistor 1, the film 31a, and the potential distribution (
11i Masakawa's resistive film 31c and the resistive film 31b are thin metal films or metal wires that short-circuit the same potential parts. Also 13
6 is a subonto light.

The figure (b) is a sectional view taken along the line X-Y in the figure (a).

In the figure, 134 is the resistance film 31a131b, potential distribution 1
This is a transparent protective film that insulates and protects the IT main resistor film 31c and the electrode film 33a133b, and allows the subont light 36 to pass therethrough. Note that 35 is a substrate, and 137 is a metal wire or the like.

FIG. 1C is an equivalent circuit diagram of the optical potentiometer according to the second embodiment of the present invention. In FIG. , Tel to T23 are external terminals, L is the overall length, and S is the position where the spont light 36 is irradiated. Further, 37 is a metal wire or the like that short-circuits the same potential portion of the resistor R.

These constitute the optical potentiometer of the second embodiment.

In this way, two or more resistive films 11a.

11b and 31a131b131c are connected in parallel, and the resistive films 11a and 11b131a131b.

Several positions at the same potential of 31c are short-circuited to each other by metal films or metal wires 17 and 37.

Therefore, it is possible to correct the potential distribution characteristic A1 due to non-uniformity such as the sheet resistance distribution of one resistive film by the potential distribution characteristic B2 such as the sheet resistance distribution of the other resistive film.

This makes it possible to improve the linearity of the composite potential distribution characteristic 2I.

Further, according to the present invention, a resistive film 31c for potential distribution correction is provided between the resistive films 31a and 131b. Therefore, it is possible to mutually correct the non-uniformity of the sheet resistance distribution of the resistor v31a131b, and further correct it by the sheet resistance distribution of the resistive film for potential distribution correction.

This makes it possible to further improve the linearity of the potential distribution characteristics.

[Effects of the Invention] As described above, according to the present invention, by connecting two or more resistive films in parallel and connecting the same potential parts by short-circuiting, it is possible to mutually correct the potential distribution. Therefore, it is possible to improve the linearity of the potential distribution characteristics and output voltage characteristics of the optical potentiometer.

Thereby, errors in measured values such as electrical and mechanical positions and angular displacements can be minimized, and measurement accuracy can be improved.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of an optical potentiometer according to a first embodiment of the present invention, FIG. 2 is an explanatory diagram of potential distribution characteristics according to a first embodiment of the present invention, and FIG. FIG. 4 is a structural diagram of an optical potentiometer according to a second embodiment of the present invention; FIG. FIG. 6 is a diagram illustrating the problems of the conventional optical potentiometer. (Explanation of symbols) 1, 11a, 11b131a131b... Resistance film, 31c... Resistance film for potential distribution correction, 2.12.3
2... Photoconductive film, 3.13a, 13b133a133b -Electroconductive film, 4
．． 14.34...Transparent protective film, 5.15.35...Group (reverse), 6.16.36...Spot light, 7...Actual potential distribution characteristics, 8.18...Ideal Potential distribution characteristics, 9.19...defective part, defective part of characteristic A, 17.
37... Metal wire, etc., 20... Defective part of characteristic B, 21... Composite potential distribution characteristic, 22... Potential distribution characteristic of resistive film, 23... Composite output voltage distribution characteristic, A ,,B,...Potential distribution characteristics, A,, B2...Output voltage distribution characteristics, P...Abrasive surface, ra + rb...Bright resistance, ν. ...DC voltage, V(s)... Potential difference, V, (s)... Output voltage, V(s) /vo... Potential distribution, V, (s) /V. ...output voltage distribution, S...position, [,...total length. Prefecture 1 Figure Bi (mi) (b ¥- desu η 54-1-n pushi tachi sashi 1 te 1 thread 54 residence Kuari P Kan → Hikika theory Iko 2 Figure 4 Figure 5

Claims (2)

[Claims] (1) Photoconductive film (12) provided on the same substrate (15)
), a pair of first and second electrode films (13a, 13b) and two or more resistive films (13a, 13b) between the electrode films (13a, 13b).
11a, 11b), and the first and second electrode films (13a, 13b) are provided with external terminals (
The two or more resistive films (11a, 11b) are connected in parallel, and one end of the resistive film (11a, 11b) is connected to the external terminal (T_1_1), and the other end is connected to the external terminal (T_1_1). Terminal (T
_1_2), and several positions of the first and second resistive films (11a, 11b) at the same potential are mutually connected to metal wires or metal films (17).
An optical potentiometer characterized by being short-circuited by. (2) On the same substrate (35), a pair of first and second electrode films (33a, 33b) and first, second and third resistive films (31a, 31b) between the electrode films (33a, 33b). , 31c)
The third resistive film (31c) is a resistive film for potential distribution correction, and the first and second electrode films (33a, 33b) are external terminals (31c).
T_2_3), and the first, second and third resistive films (31a, 31b, 31c
) are connected in parallel, and the resistive films (31a, 31b,
31c) is connected to the external terminal (T_2_1),
The other end is connected to the external terminal (T_2_2), and the first, second and third resistive films (31a, 31b, 31c
2. The optical potentiometer according to claim 1, wherein several positions having the same potential are short-circuited to each other by a metal wire or a metal film (37).