JP3208518B2 - Capacitive detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitance type detection device.

[0002]

2. Description of the Related Art Conventionally, a capacitance type sensor for detecting various information using a capacitance change type converter has been disclosed in Japanese Patent Laid-Open No. 59-112.
No. 225 gazette. In this basic configuration, a reference capacitance element is formed by a pair of electrodes, and a detection electrode paired with one of the electrodes is provided to form a detection capacitance element. Then, when a human body or the like approaches the detection electrode side, the capacitance of the detection capacitance element changes, and the change in the capacitance is detected by comparison with the capacitance of the reference capacitance element.

[0003]

The above-mentioned sensor can be used for various purposes as a non-contact type object detection sensor, but the detection range is limited to one area on the detection electrode side. It can only detect whether or not an object exists in the area. Therefore, for example, if an attempt is made to detect the position of a moving object within its movement range, an independent sensor including a reference capacitance element and a detection capacitance element is provided within the movement range of the object. A plurality of sets must be provided within the moving range to detect which sensor has generated the output.

In this configuration, a plurality of sets of sensors each including a reference capacitance element and a detection capacitance element must be provided, which results in a complicated configuration and high cost.

An object of the present invention is to provide a capacitance type detection device capable of detecting a region where an object is present from a plurality of regions in a non-contact manner with a simple configuration.

[0006]

According to the present invention, three or more electrodes formed apart from each other, an object movable between or on the electrodes, and an adjacent one of the electrodes are provided. The above object is achieved by providing a control circuit for comparing the capacitances of a plurality of capacitance elements constituted by electrodes to detect the position of the object to be detected.

The control circuit includes a pulse generating means and a selecting means for sequentially selecting three adjacent electrodes from the respective electrodes and selectively forming two capacitors by the selected three electrodes. A pair of delay means for respectively delaying and outputting the pulse from the pulse generation means for a time corresponding to the value of the capacitance of each capacitor selected by the selection means, and outputting the pair of delay means. A data output unit that outputs determination data of the magnitude of the capacitance of each of the capacitors in accordance with a pulse phase difference; a storage unit that stores the determination data; and the detected data from the determination data stored in the storage unit. The above object is achieved by including control means for specifying the position of an object.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to one embodiment shown in the drawings. In this example, the present invention is applied to roulette.

In FIG. 1, reference numerals 1, 2, 3, 4, 5, and 6 denote electrodes, which are radially arranged at intervals of 60 degrees as shown in the present embodiment. Are equal. Reference numerals 7, 8, 9, 10, 11, and 12 are switches constituting selection means. Reference numeral 13 denotes a pulse generation circuit which constitutes a pulse generation means.
5, a capacitor 16, etc., for generating a reference pulse. Reference numerals 17 and 18 denote resistors, and reference numeral 19 denotes a variable resistor. A pair of delay means are selectively formed by these resistors and the capacitance between the electrodes 1 to 6. Reference numerals 20 and 21 denote inverters, and reference numeral 22 denotes a flip-flop constituting data output means. 2
Reference numerals 3 and 24 are gate circuits. Numeral 25 denotes an arithmetic circuit constituting control means, storage means and designation switching means.
U, ROM, RAM, etc., which control various operations. Reference numeral 26 denotes a sphere constituting the object to be detected. In addition, the pulse generation circuit 13, the switches 7 to 12, the electrodes 1 to 6, and the resistor 1
A control circuit 27 is composed of the delay means including the elements 7 and 18 and the variable resistor 19, the flip-flop 22, and the arithmetic circuit 25. Reference numeral 28 denotes a display device which displays an area where the arithmetic circuit 25 determines that the ball 26 exists. In this example, the electrodes 1 to 6
The area designated by the arithmetic circuit 25 is displayed from the area divided into six by the above.

FIG. 2 is a front view and a sectional view of a roulette in which electrodes 1 to 6 are arranged. The components having the same numbers as those in FIG. 1 are the same. FIG. 2B is a sectional view taken along line xx of FIG. 2A.

In FIG. 1, reference numeral 29 denotes a roulette table on which electrodes 1 to 6 are radially embedded on one surface side at intervals of 60 degrees as described above.

Reference numeral 30 denotes an insulating sheet which is laid on one side of the roulette table 29, on which the ball 26 moves.

A wall 31 prevents the ball 26 from jumping out of the roulette table 29.

Next, the operation will be described with reference to FIG.

When the rotation of the ball 26 on the roulette table 29 is stopped and a detection start signal is input to the terminal T, the arithmetic circuit 2
Reference numeral 5 outputs a designated switching signal for connecting the switches 7, 8, 9, 10, 11, 12 to the terminals a, f, k, p, t, x, respectively. The terminals a, e, i, m, q, u are connected to one end of the resistor 18 and the inverter 20, and the terminals b, f, j, n, r, v are connected to one end of the resistor 17 and the inverter 21, Terminals c, g, k, o, s, and w are connected to a ground terminal, and terminals d, h, 1, p, t, and x are open.

According to the designation switching signal, the electrode 1 is connected to the inverter 20, the electrode 2 is connected to the GND, the electrode 3 is connected to the inverter 21, and the electrodes 4, 5, and 6 are open. Therefore, a capacitor is formed by the electrodes 1 and 2 and the electrodes 2 and 3. Each capacitor delays the pulse (FIG. 3A) generated by the pulse generation circuit 13 by a time corresponding to the value of the capacitance. Output to the inverters 20 and 21, respectively.

Here, the values of the capacitances of the capacitors formed by the electrodes 1 and 2 and the capacitors formed by the electrodes 2 and 3 are the same. Since the intervals are also equal, the values of these two capacitances are equal when there is no object between the electrodes. The same applies to a capacitor formed by other adjacent electrodes, for example, a capacitor formed by the electrodes 3 and 4 and the electrodes 6 and 1. That is, when no object exists between the electrodes, the capacitance of the capacitor formed by the adjacent electrodes becomes equal.

At this time, if the sphere 26 exists between the electrodes 1 and 2, the capacitance of the capacitor formed by the electrodes 1 and 2 becomes larger than the capacitance of the capacitor formed by the electrodes 2 and 3. Therefore, as shown in FIGS. 3B and 3C, the delay amount of the input pulse to the inverter 20 becomes larger than the delay amount of the input pulse to the inverter 21.
From 1, pulses whose phases are shifted as shown in FIGS. 3D and 3E are generated and input to the flip-flop 22. In addition,
3A, 3B, 3C, 3E, 3F, 3G, and 3H are shown in FIGS.
FIG. 4 is a voltage waveform diagram at points D, E, F, G, and H.

The flip-flop 22 is triggered by the falling edge of the output pulse of the inverter 21, reads the output level of the inverter 20, and outputs the judgment data. In this case, since the output level of the inverter 20 is “1”, the output H of the flip-flop 22 becomes “1”. At this time, as shown in FIG. 3F, pulses P1 and P2 having a pulse width corresponding to the phase difference between the respective pulses are output from the gate circuit 23.
... occurs. Output pulses P1, P2 of gate circuit 23
Are input to the gate circuit 24. Since the gate circuit 24 is open only while the reference pulse from the pulse generation circuit 13 is "1", the pulses from the gate circuit 23 are not shown in FIGS.
Only the pulse corresponding to the phase difference of the falling edge of the pulse passes. That is, the pulse width of the pulse that has passed through the gate circuit 24 is determined by the capacitance of the electrodes 1 and 2 and the electrodes 2 and 3
Shows the difference in the capacitance of the capacitors due to

The arithmetic circuit 25 stores the designation switching signals of the switches 1 to 6, the output level of the flip-flop 22, and the pulse width data of the gate circuit 24 as a set of data in the RAM therein.

When the storage of the above three types of data is completed, the arithmetic circuit 25 switches the switches 7, 8, 9, 10, 11,
12 is switched to terminals d, e, k, n, t, and x, respectively. The electrode 2 is connected to the inverter 20 and the electrode 3 is connected to GND by this designated switching signal.
The electrode 4 is connected to the inverter 21 and the electrodes 5, 6, and 1 are open. Therefore, a capacitor is formed by the electrodes 2 and 3 and the electrodes 3 and 4. Each capacitor delays the pulse generated by the pulse generation circuit 13 by a time corresponding to the value of the capacitance, and the inverters 20 and 21 respectively. Output to That is, the capacitances of the capacitors composed of the electrodes 2 and 3 and the capacitors composed of the electrodes 3 and 4 are compared.

Then, similarly to the above, the designation switching signal and the outputs of the flip-flop 22 and the gate circuit 24 are stored in the RAM in the arithmetic circuit 25. Now, the sphere 26 is the electrode 1,
2, the capacitances of the two capacitors formed by the electrodes 2 and 3 and the electrodes 3 and 4 become equal, and the delay amount of the input pulse to the inverter 20 and the
The delay amounts of the input pulses to are equal.

Therefore, the output pulses of the inverters 20 and 21 have the same phase. Therefore, the output H of the flip-flop 22 is held at "0" or "1", and the outputs of the gate circuits 23 and 24 are held at "0".

That is, when the sphere 26 does not exist between or on the electrodes of each capacitor, the gate circuit 2
4 becomes "0".

The switches 7, 8, 9, 10, 11,
12 are sequentially switched and the magnitudes of the capacitances of the capacitors formed by the adjacent electrodes are relatively compared, and the three types of data are sequentially stored in the RAM in the arithmetic circuit 25 as one set in the same manner as described above. I will do it.

When all the comparisons of the capacitances of the capacitors formed by the adjacent electrodes are completed, the arithmetic circuit 2
5 compares the data stored in the RAM therein,
It detects between the electrodes having the largest capacitance. That is, it detects between the electrodes where the sphere 26 exists.

This detection method will be specifically described. The data having the largest pulse width data output from the gate circuit 24 is detected from the data stored in the RAM in the arithmetic circuit 25 and compared with the specified switching signal stored in combination with the data. The two types of capacitors selected are selected, and then one of the two types of selected capacitors is detected by reading whether the output data of the flip-flop 22 is "1" or "0". That is, the area where the sphere 26 exists is specified from the area defined by the electrodes.

In this case, the designation switching signal for connecting the switches 7 to 12 to the terminals a, f, k, p, t, and x, respectively, and the data of which the output of the flip-flop 22 is "1" are stored as a set. Since the pulse width data of the gate circuit 24 is the largest, it is determined from the designated switching signal and the output “1” of the flip-flop 22 that the ball 26 exists in the area defined by the electrodes 1 and 2.

The arithmetic circuit 25 causes the display device 30 to display the area where the ball 26 exists.

As described above, the area where the ball 29 exists can be detected from the plurality of areas in a non-contact manner.

In the present embodiment, the designation switching signal, the output of the flip-flop 22 and the output of the gate circuit 24 are all stored in the RAM in the arithmetic circuit 25, and the stored data is compared, so that the sphere 26 exists. Is detected, the first three types of data to be detected are added to the R
Each time the switches 7 to 12 are switched, the pulse width data of the gate circuit 24 stored in the RAM in the arithmetic circuit 25 is compared with the pulse width data of the newly input gate circuit 24. 1 with
Only a set of data may be stored in the RAM in the arithmetic circuit 25. In this case, one of the switches 7 to 12
Is completed, the area where the ball 26 exists can be detected from a set of data stored in the RAM in the arithmetic circuit 25.

By switching the detection electrodes sufficiently faster than the rotation speed of the ball 26, the area where the ball 26 is rotating can be displayed.

In this embodiment, the electrodes are arranged radially at equal angular intervals. However, the arrangement of the electrodes is not limited to this, and they may be arranged linearly at equal intervals or may be changed as appropriate. In this case, it is necessary to arrange the same electrodes at equal intervals as described above.

In the above example, six electrodes are used.
The number of electrodes can also be changed as appropriate. However, also in this case, it is necessary to arrange the same electrodes at equal intervals as described above.

In the above description, the present invention is applied to the roulette. However, the present invention is not limited to this. For example, it is composed of a plurality of electrodes of the same shape arranged at equal intervals on one circumference and an indicator electrode that rotates with the rotation of the knob, and this indicator electrode comes into contact with any one of the plurality of electrodes. Accordingly, the present invention can be used for a rotary switch that generates an output corresponding to the contacted electrode. That is, a non-contact rotary switch can be realized. In this case, since the area where the indicator electrode exists can be detected in a non-contact manner, problems such as poor contact can be solved.

[0036]

According to the present invention, an area where an object exists can be detected in a non-contact manner from a plurality of areas with a simple configuration.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram showing one embodiment of the present invention.

FIG. 2 is a detailed view of a main part of FIG. 1;

FIG. 3 is a timing chart for explaining the operation of FIG. 1;

[Explanation of symbols]

 1-6 electrodes 7-12 selection means 13 pulse generation means 22 data output means 25 storage means, designation switching means, control means 26 object to be detected 27 control circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01B ^7/ 00-7/34

Claims (2)

(57) [Claims] 1. A plurality of electrodes formed apart from each other, an object to be detected that can move between the electrodes or on the electrodes, and a plurality of capacitors formed by adjacent electrodes among the electrodes. And a control circuit for comparing the capacitances of the elements to detect the position of the object to be detected. 2. The control circuit according to claim 1, wherein the control circuit sequentially selects a pulse generating unit, and three adjacent electrodes from each of the electrodes.
Selection means for selectively forming two capacitors by the selected three electrodes; and a pulse from the pulse generation means for a time corresponding to a capacitance value of each capacitor selected by the selection means. A pair of delay means for respectively outputting a delay; a data output means for outputting determination data of the magnitude of the capacitance of each of the capacitors according to a phase difference between pulses output by the pair of delay means; Storage means for storing data; designation switching means for sequentially changing three adjacent electrodes selected by the selection means each time the determination data is output; and detecting the detected data from the determination data stored in the storage means. A capacitance-type detection device, comprising: control means for specifying a position of an object.