JPS61274218A - Position-detecting apparatus - Google Patents

Abstract

PURPOSE:To attempt silencing of rubbing noise by non-contacting arrangement and removal of influence by external magnetic field, by converting an amount of mechani cal change into positional change of spot light and constructing an photo-electric detecting apparatus conducting the positional detection of the spot light. CONSTITUTION:A beam of light from a source 1 is limited to spot light by stationary slitted plate 2 and moving slitted plate 3 and projected onto a light-receiving surface of a detecting apparatus 4 oriented in the some direction as the slit of the stationary slitted plate 2. The spot light, following a travel of the moving slitted plate 3a, moves along the light-receiving surface of the apparatus 3 with the an inclined part of the slit only. The apparatus 4 emits an electric signal by continuously following a position of the spot light that travels linearly, consequently, it feeds out a position of the spot light projected on the light-receiving surface to a detecting means 5 as an electric signal. A larger inclination angle of the slitted part can give higher ratio of displace ment amount A of the moving slitted plate 3a versus displacement amount B on the light-receiving surface of the spot light and out of the displacement range of the moving slitted plate 3a, high accuracy position detecting can be realized only on both ends and in the middle.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a detection device for detecting changes in position or angle.

2. Description of the Related Art A potentiometer is known as a device for detecting changes in position or angle. This converts the amount of mechanical change into a change in resistance value, and has the characteristics of a simple structure and a relatively large output. There is a non-contact method used.

Problems to be Solved by the Invention However, conventional contact potentiometers have the problem that the resistance surface is damaged due to sliding between the resistance part and the contact, causing changes in contact resistance, making stable detection impossible over a long period of time. Was. Non-contact potentiometers using magnetoresistive elements still have no sliding noise, but have the problem of not being able to perform stable detection when external noise magnetic fields are large.

In view of the above problems, the present invention provides a highly stable position detection device that is free from sliding noise and unaffected by external magnetic fields.

Means for Solving the Problems In order to solve the above problems, the position detection device of the present invention limits the slit light to a spot light, moves the spot light, and detects it with a one-dimensional position detector. It has a configuration.

Operation The present invention uses the above-described configuration to configure a photoelectric detection device that converts the amount of mechanical change into a change in the position of the spot light and detects the position of the spot light, thereby reducing sliding noise due to non-contact. , and the influence of external magnetic fields will be removed.

Embodiment Hereinafter, a position detection device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of a position detection device according to the present invention. In FIG. 1, 1 is a light source, 2 is a fixed slit plate, and slit light is obtained by both. 3 is a movable slit plate constituting a movement limiting means for restricting the slit light to a spot light and moving this spot light; 4 is a one-dimensional semiconductor position detector (hereinafter referred to as a detector); 5 is a This is a detection means for processing the output signal of this detector 4. FIG. 2 shows a structural diagram of the movable slit plate, and FIG. 3 shows a block diagram of the detection means 5. Second
The figure shows three types of examples of the movable slit plate 3, all of which are characterized in that the slits are not cut in a straight line.

The operation of the position detection device configured as described above will be described below.

First, the light emitted from the light source 1 is limited to a spot light by the fixed slit plate 2 and the movable slit plate 3, and is placed on the light receiving surface of the detector 4 placed in the same direction as the slits of the fixed slit plate 2. is projected on. Here, the slit plate 3a shown in FIG. 2a as the moving slit plate 3
Suppose we use The slit of the movable slit plate 3a in FIG.
The other parts are cut in the same direction as the moving direction. As the movable slit plate 3a moves, the spot light moves on the light receiving surface of the detector 4 only at the inclined portion of the slit.

The detector 4 outputs a continuous electric signal according to the position of the spot light moving linearly, and outputs the position of the spot light projected onto the light receiving surface as an electric signal to the detecting means 6. Only in the inclined part of the slit,
The spot light moves by B on the light receiving surface of the detector 4 while the movable slit plate 3a moves by A. Therefore, by detecting the position of the spot light on the light receiving surface, the movement can be determined by detecting the position of the spot light on the light receiving surface. The position of the slit plate 3 can be detected, but if the angle of inclination of the inclined slit portion is made large, the movement of the spot light on the light receiving surface with respect to the movement amount A of the moving slit plate 3a described above can be detected. The ratio of the amount B can be increased, and position detection with higher accuracy than before can be realized only at both ends and the center of the movement area of the movable slit plate 3a. Furthermore, when a movable slit plate 3b is used instead of the movable slit plate 3a, based on the same principle, the central part of the moving area of the movable slit plate 3b becomes smaller than when the movable slit plate 3a is used. Position can be detected with high precision. Furthermore, if the entire moving area of the movable slit plate is to be position-detectable and only a certain part of the moving area is to be detected with high precision, a movable slit plate 3C may be used instead of the movable slit plate 3a. A slit inclined with respect to the moving direction is provided in the entire area of the moving slit plate, and a portion where highly accurate position detection is required (the moving slit 3
In case c, it is sufficient to use a movable slit plate in which the slope of the slit is increased only at both ends).

Next, the configuration and operation of the detection means 5 will be explained.

6.7.8 is an amplifier, 9 is an adder that adds the respective outputs of amplifiers 6 and 7, 1o is a subtracter that performs subtraction between each output of amplifiers 6 and 7, and 11 is the output of adder 9. Subtractor 10
This is a divider that performs division with the output of .

With the above configuration, the two outputs 4a of the detector 4.

4b is calculated, and the position of the spot light on the position detector 4 is output.

As described above, according to this embodiment, the position detection device converts the light emitted from the light source into slit light, limits the slit light to spot light, and limits the spot light to the necessary range for position detection. By moving the sensor and detecting it with a one-dimensional semiconductor device detector, the structure is simple and stable and highly accurate position detection can be performed.

In the embodiments, a linear movement type position detection device has been described, but it goes without saying that the present invention may also be used for a rotational movement type position detection device.

Moreover, although only the three types of moving slit plates shown in FIG. 2 have been described as examples of the moving slit plate, other moving slit plates that meet the conditions may be used.

Furthermore, it goes without saying that the slits on the movable slit plate are not limited to linear shapes, but may also be curved shapes.

As described above, in this embodiment, the light emitted from the light source is converted into slit light, the slit light is limited to spot light, and the spot light can be used for high-precision position detection without sacrificing the essential characteristics of position detection. Accordingly, it is possible to realize an excellent position detection device that can obtain the effect of being able to perform the following operations.

Effects of the Invention As described above, the present invention uses a slit light, limits the slit light to a spot light, moves the spot light, and detects it with a one-dimensional position detector. Accordingly, it is possible to realize an excellent position detection device that can perform highly stable position detection without dynamic noise and unaffected by external magnetic fields.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, Fig. 2 a, b
, C is a structural diagram of a movable slit plate according to an embodiment of the present invention, and FIG. 3 is a block diagram of a detection means according to an embodiment of the present invention. 1...Light source, 2...Fixed slit plate,
3...Moving slit plate, 4...One-dimensional semiconductor device detector, 5...Detecting means, 6, 7
．． 8...Amplifier, 9...Adder, 1o
・・・・・・Subtractor, 11・・・・・・Divider. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
+ source, f - 禮咄すJλ Fig. 2

Claims (2)

[Claims] (1) A slit light, a movement limiting means that limits the slit light to a spot light and moves the spot light, a one-dimensional position detector that detects the position of the spot light, and a one-dimensional position detector that detects the position of the spot light. 1. A position detection device comprising: detection means for processing an output signal. (2) The movement limiting means is characterized in that it is configured such that the ratio between its own movement amount and the movement amount of the spot light on the light receiving surface of the one-dimensional position detector has two or more different values. A position detection device according to claim 1.