JPH081585B2 - Position detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be used as an information input device for industrial equipment such as office automation equipment and other computers, and for example, position detection for detecting the operation position of an operation plate for inputting information. Regarding the device.

[0002]

2. Description of the Related Art FIG. 9 is a schematic front view showing a screen position sensor having an interrupter structure provided in a copy machine, and FIG. 10 is a schematic sectional view of the screen position sensor.

In the screen position sensor described above, an operation unit for instructing the number of copies, size, enlargement ratio, etc. (hereinafter referred to as display name) is displayed on the display 11 made of a rectangular liquid crystal plate. A finger is brought into contact with any one of these operation portions to give an instruction, and an instruction signal according to the instruction is input to the copy machine.

In this screen position sensor, the display-1
Light-emitting diodes L ₁₁ , L ₁₂ ... L ₁ on the upper side of ₁
n are provided, and photo diodes P ₁₁ , P ₁₂ ... P ₁ n are provided on the lower side of the display 11 so as to face the light emitting diode. Is provided.

Further, on the left side of the display-11,
The light emitting diodes L ₂₁ , L ₂₂ ... L ₂ n, and the photo diodes P ₂₁ , P _22. P ₂ n are arranged respectively.

The above-mentioned light emitting diode and photo diode are provided in a frame 12 surrounding the display 11.
The light emitted from each light emitting diode is projected onto the plate surface of the display 11.

Accordingly, when the abutting the finger to the display name 11a with Display -11 emitting diode - lighting beam 13X de L _12, L _22, since 13Y is blocked by a finger, the photo-diode - de input light de P _12, P ₂₂ is eliminated - photo diode of. As a result, the position of the display name 11a is determined by the row and column, and the command signal according to the display name is input to the copy machine.

[0008]

In the above-mentioned screen position sensor, the number and positions of display names are determined by the size of the frame body 12, so that the degree of freedom in designing and manufacturing is low, and the number of display names is large. Light emitting diode and photo diode
There is a problem that the number of cards increases.

Further, since the row and the column of the display name of the display 11 are determined by the installation of the light emitting diode and the photo diode, the degree of freedom in designing and manufacturing is also reduced in this respect.

By utilizing the above-described screen position sensor according to the present invention, the designated position of the display name can be detected by the light source and the light receiver that are as small as possible, and the position of the display name can have a degree of freedom. The purpose is to develop a position detection device that can

[0011]

In order to achieve the above-mentioned object, in the present invention, at least three light sources for projecting light from respective directions parallel to the plate surface of the operation plate and close to each light source are provided. Each light receiver arranged and a pair of light sources project light, and the light reflected by the object to be detected that indicates the operation position on the operation plate is received by each light receiver close to these light sources. A means for separately calculating the luminance of the detected object and calculating the ratio thereof, the light is projected by another pair of light sources, and the light reflected by the object is received by each light receiver close to these light sources, And a means for calculating the ratio of the brightness of the detected object generated for each light source from the received light output, and detecting the operation position on the operation plate from the brightness ratio calculated in two ways. Propose a position detection device

[0012]

In the position detecting device described above, the light reflected by the object to be detected is received by the respective light receivers which are close to these light sources, by projecting light by the pair of light sources. Then, from the light reception signals output from the respective light receivers, the brightness of the detected object caused by the projection of these light sources is obtained, and then the brightness ratio thereof is calculated.

Further, by projecting light by another pair of light sources, the reflected light of the object to be detected is received by each of the light receivers brought close to these light sources. Then, from the light reception signals output from the respective light receivers, the brightness of the detected object caused by the projection of these light sources is obtained, and then the brightness ratio thereof is calculated.

The position of the object to be detected is detected from the brightness ratio calculated in the above two ways. Therefore, if it is implemented as a screen position sensor of a copy machine or the like, the finger that has instructed the operation unit is detected as the detected object, and thus the instructed display name is determined.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is embodied as a screen position sensor of a copying machine will be described with reference to the drawings. FIG.
Is a simplified front view of the screen position sensor. The rectangular operation plate 21 has a power switch with “ON”, “OFF”,
Paper size "A-1", "A-2" ..., "B"
-1 "," B-2 "..." Enlargement "," Standard ",
Various display names necessary for operating the copy machine, such as "reduction" and "copy number" of the copy, are added. The operation plate 21 can also be configured as a display plate using liquid crystal or the like.

Two light emitting diodes 22A and 22 as light sources are provided near one of the long sides of the operation plate 21.
B is provided, and light emitting diodes 22C and 22D as light sources are provided near one side of the short side. The light emitting diodes 22A and 22B are arranged at positions equidistant from the vertical center line (virtual line) 23A of the operation plate 21, and the light emitting diodes 22C and 22D are located in the horizontal center line (virtual line). The line) 23B is arranged at an equal distance.

Further, the light emitting diode 22A is provided with a photo diode 24A as a light receiver in close proximity thereto so that the reflected light by the projection of the light emitting diode 22A is received by the photo diode 24A. I am doing it. Similarly, the light emitting diodes 22B, 22C and 22D are provided as photodetectors at positions where the photo diodes 24B, 24C and 24D are close to each other.

Next, the operation of the above-mentioned screen position sensor will be described by taking as an example the case where the finger 25 is brought into contact with the display name "A-2" in order to select the paper size "A-2".

First, when the light emitting diode 22A is projected, the projected light is reflected by the fingers 25 and received by the photo diode 24A. Also, the light emitting diode
When the beam 22B is projected, the projected light is similarly reflected by the finger 25 and received by the photo diode 24B.

Assuming that the light emitting diodes 22A and 22B are point light sources, the brightness of the finger 25 is equal to that of the light emitting diode 2.
It becomes inversely proportional to the square of the distance from 2A and 22B, and this luminance is measured by the photo diode.

Then, the photo diodes 24A, 24
The brightness ratio of the finger is calculated from the received light signal of B. That is, the brightness E of the finger 25 when the light emitting diode 22A is projected.
a and fingers 25 when the light emitting diode 22B is projected.
Then, the ratio with the luminance Eb of is calculated.

The luminances Ea and Eb are 1: 1 on the center line 23A of the operation plate 21, and the locus of Ea / Eb = K ₁ is as shown in FIG. That is, the central line 23A
The brightness ratio of the finger 25 when the display name on the left side is instructed changes to K ₁ = 10/9 = 1.11 to K ₁ = 10 / 0.5, and the display name on the right side is instructed. When the luminance ratio is K ₁ = 9/10 = 0.9 to K ₁ = 0.5 / 10 = 0.
It changes like 05.

Next, the light emitting diode 22C is projected,
The light reflected by the finger 25 is received by the photo diode 24C, the light emitting diode 22D is projected in the same manner, and the light reflected by the finger 25 is received by the photo diode 24D.

Then, the photo diodes 24C, 24
From the received light signal of D, the ratio K ₂ between the brightness Ec when the light emitting diode 22C is projected and the brightness Ed when the light emitting diode 22D is projected is calculated. The brightness ratio K ₂ = Ec / Ed calculated in this way changes similarly to that shown in FIG.

When the brightness ratios K ₁ and K ₂ are calculated as described above, the position of the instructed finger can be determined from the intersection of the loci of these brightness ratios. For example, as shown in FIG. 1, when the finger 25 is applied to the display name and the paper size “A-2” is designated, as shown in FIG. 3, K ₁ = 1.43, K ₂ =
Since the intersection of 1.66 is detected, this position is determined as the paper size "A-2", based on K _1, K ₂ command signals paper size "A-2" copy - is input to the machine be able to. The same applies when each of the other display names is designated by a finger.

FIG. 4 is a block diagram showing an electric circuit of the above-mentioned screen position sensor. In this figure, 26A-2
Reference numeral 6D is a light source circuit including the above-mentioned light emitting diodes 22A to 22D and these drive circuits, and 27 is a distributor which inputs a signal from a signal source 28 and sequentially turns on the light emitting diodes 22A to 22D.

Reference numerals 29A to 29D are photodetector circuits equipped with the above-described photo diodes 24A to 24D and an amplifier, and 30.
A to 30D are logarithmic conversion circuits, 31A to 31D are gate circuits which open the gate in synchronization with the lighting signals of the light emitting diodes 22A to 22D, 32A and 32B are differential amplifiers, 33
Is a CP that outputs a command signal according to the designated display name
U.

In this circuit example, the light source circuits 26A to 26D are provided.
Are sequentially driven to sequentially turn on the light emitting diodes 22A to 22D. As a result, the reflected light of the finger that indicates the display name is sequentially received by the photo diodes 24A to 24D.

The received light signal is amplified by the light receiver circuits 29A to 29D, converted into a voltage, and converted into a logarithmic conversion circuit 30.
A to 30D. Then, the logarithmic conversion circuit 30A,
The light receiving signals Sa and Sb logarithmically converted by 30B are logarithmically converted to the light receiving signals Sc and Sd.
Respectively input to the differential amplifier 32B.

Therefore, in the differential amplifier 32A, Lo
gSa-LogSb = Log (Sa / Sb) is calculated, and in the differential amplifier 32B, LogSc-LogSd =
Log (Sc / Sd) is calculated. As a result, Log
By (Sa / Sb) and Log (Sc / Sd), the signals of the already-extended luminance ratios K ₁ and K ₂ are input to the CPU 33.

The CPU 33 outputs a command signal corresponding to the display name designated by the finger from the brightness ratio signal input as described above, and operates the copy machine in accordance with the command signal.

Although one embodiment of the present invention has been described above, one of the brightness ratios turns on the light emitting diodes 22A and 22B, and the other brightness ratio indicates the light emitting diodes 22B and 22C.
Can be calculated by turning on, and similarly, the light emitting diodes 22C and 22D are turned on to obtain one luminance ratio, and the light emitting diodes 22D and 22B are turned on to obtain the other luminance ratio. be able to. Regarding the arrangement of the light emitting diodes 22A to 22D and the photo diodes 24A to 24D, it is not necessary to arrange them in parallel with the long side and the short side of the operation plate 21.

FIG. 5 shows an arrangement example in which the straight line connecting the light emitting diodes 22C and 22D is an obtuse angle with respect to the straight line connecting the light emitting diodes 22A and 22B. An example of such an arrangement is shown. Even if the light emitting diodes 22A to 22D are arranged in this manner, the same operation as in the above-described embodiment can be performed. Incidentally, photo diodes 24A to 24D are attached to each of the light emitting diodes 22A to 22D in the same manner as above.

Further, as shown in FIG. 7, the light emitting diodes 22A and 22C are also used as a single light emitting diode 22E, and a photo diode 24E is arranged near the light emitting diode 22E. It may be configured to allow it.

In the case of carrying out in this way, the reflected light due to the lighting light of the light emitting diodes 22B and 22E is received by the photo diodes 24B and 24E, and the luminance ratio K ₁ is calculated from this received light signal, Also, the light emitting diodes 22D, 22
The light reflected by the lighting light of E is photo diode 24D,
Light is received at 24E, and the brightness ratio K ₂ is calculated from the received light signal.

On the other hand, in the above-mentioned embodiment, the lighting of the light emitting diodes 22A to 22D is radiated onto the surface of the operation plate 21, but as shown in FIG. It may be configured to emit light.

In this case, the operation plate 21 is made of an elastic material, and each position of the display name is formed as a push button 34 that can be pushed. A columnar protrusion 34a is provided on the back side of the push button 34, and the columnar protrusion 34a is formed.
Mirror the surface of the. According to this structure, when the push button 34, which is the display name, is pushed as shown by the chain double-dashed line in the figure, the light emitted from the light emitting diode 22A emits the columnar protrusion 34.
It is reflected by a and this reflected light is photo diode 24A.
Is received by.

Although only one push button 34 is shown, the push button structure is similarly applied to the other display names, and the light emitting diodes 22B to 22D and the photo diode are also used.
The terminals 24B to 24D are similarly arranged.

In addition, in carrying out the present invention, light emitting diodes 22A to 22D and photo diodes 24A to
24D does not have to be a single unit, and each can be configured as a plurality of light emitting diodes and photo diodes, and the light emitting diodes 22A to 22D and the photo diodes can be formed.
When the diodes 24A to 24D must be arranged apart from the operation plate 21, an optical system such as a lens, a flat mirror, a curved mirror, etc. is used, and these light emitting diode and photo diode are The configuration is similar to that arranged near the operation plate 21.

Further, the light emitted from each of the light emitting diodes 22A to 22D is modulated with a different frequency or has a different light wavelength, and the photo diodes 24A to 24D are the light reflected by the corresponding light emitting diodes. By providing a light receiving filter and a light receiving circuit so as to receive light, the light emitting diodes 22A to 22D can be simultaneously turned on to detect the position.

Although the embodiments of the present invention applied to the copy machine have been described above, the same can be applied to any electric equipment provided with an operation plate having a non-contact switch structure.

[0042]

As described above, in the position detecting device of the present invention, the number of light sources and light receivers can be reduced as much as possible, and the number of detecting positions and the number of light receiving devices can be changed by the frame and the light source as in the conventional device. It is not limited and can be electrically set arbitrarily by changing the luminance ratio of the detected object. Further, in the present invention, the position of the detected object is detected by utilizing the brightness ratio, so that the position detection device is not affected by the reflectance of the detected object.

[Brief description of drawings]

FIG. 1 is a simplified front view showing an example in which the present invention is implemented as a screen position sensor of a copy machine.

FIG. 2 is a diagram showing a locus of a luminance ratio of a finger obtained by projecting two light emitting diodes.

[Fig. 3] Detecting the finger position from the intersection of the luminance ratios K ₁ and K ₂ ,
It is explanatory drawing which shows the state which fixes the display name designated by the finger.

FIG. 4 is a block diagram showing an electric circuit of the screen position sensor described above.

FIG. 5 is an explanatory view similar to FIG. 3, showing an example in which the arrangement positions of the light emitting diode and the photo diode are changed.

FIG. 6 is an explanatory view similar to FIG. 3, showing another example in which the arrangement positions of the light emitting diode and the photo diode are changed.

7 is an explanatory view similar to FIG. 3, showing an example in which a light emitting diode and a photo diode are used in common.

FIG. 8 is a cross-sectional view of essential parts showing an embodiment in which a display name has a push button structure.

FIG. 9 is a simplified front view showing a screen position sensor of a copy machine shown as a conventional example.

10 is a schematic cross-sectional view of the screen position sensor shown in FIG.

[Explanation of symbols]

 21 Operation Plate 22A to 22D Light Emitting Diode 24A to 24D Photo Diode 25 Fingers 26A to 26D Light Source Circuit 27 Distributor 28 Signal Source 29A to 29D Photoreceptor Circuit 30A to 30D Logarithmic Conversion Circuit 31A to 31D Gate Circuit 32A, 32B Differential amplifier 33 CPU

Claims (1)

[Claims] 1. At least three light sources for projecting light from respective directions parallel to the plate surface of the operation plate, respective light receivers arranged close to the respective light sources, and light projection by a pair of light sources,
The light reflected by the detected object indicating the operation position on the operation plate is received by each light receiver close to these light sources,
A means for calculating the ratio of the brightness of the detected object generated for each light source from the received light output, and a means for projecting the light by another pair of light sources, and receiving the light reflected by the detected object for each light source approaching these light sources. And a means for calculating the ratio of the brightness of the detected object generated for each light source from the received light output, and detecting the operation position on the operation plate from the brightness ratio calculated in two ways. A position detecting device characterized by the above.