JPH0659025A - Multiplex optical sensor - Google Patents

Abstract

PURPOSE:To make it possible to detect position with high accuracy even by a cheap element which has bad directivity and mount a multi-type optical sensor in such a way that optical axes of all the light emitting/receiving elements are parallel concerning the multi-type optical sensor which employs more than two sets of adjacent optical sensors which detect presence of an object by utilizing a mechanism which receives light radiated from the light emitting element by the light receiving element and cannot receive light by the light receiving element when an object intrudes between them. CONSTITUTION:A multi plex optical sensor in which more than two sets of transparent optical sensors are arranged adjacent is constituted in such a way that light emitting elements A, B themselves and light receiving elements a, b themselves of adjacent optical sensors S1, S2 are not adjacent by arranging the light emitting element A and the light receiving element b of the adjacent optical sensors S1, S2 adjacent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a light emitting element and a light receiving element which are arranged so as to face each other, and light emitted from the light emitting element is received by the light receiving element. The present invention relates to a multi-type optical sensor that uses two or more adjacent optical sensors that detect the presence or absence of an object. The optical sensor has an advantage that it can detect the presence or absence and the position of a target object in a non-contact manner.

[0002]

2. Description of the Related Art FIG. 5 is a diagram in which optical sensors are classified according to the arrangement type. (1) FIG.
When the object 1 does not exist, the light emitted from the light emitting element A is not received by the light receiving element a. In the case of such a reflection type optical sensor, since the light emitting element A and the light receiving element a are arranged relatively close to each other, both elements A and a are attached to the integrated holder 2.

On the other hand, in FIG. 2 (2), the light emitting element A and the light receiving element a are arranged so as to face each other, and when there is an object 1 between them, the light emitted from the light emitting element A is blocked by the object 1. When the light receiving element a cannot receive light and the object 1 does not exist, the light from the light emitting element A is received by the light receiving element a. In this case also, since the distance between the light emitting element A and the light receiving element a is small, they are both attached to the integrated holder 3.

Also in FIG. 3 (3), the light emitting element A and the light receiving element a are arranged so as to face each other and are of a transmission type, but the distance between the light emitting element A and the light receiving element a is large. Therefore, the light emitting element A and the light receiving element a are attached to different holders 4 and 5, respectively.

When the distance between the light emitting element A and the light receiving element a is small as shown in FIGS. 1 (1) and 2 (2), the light emitted from the light emitting element A is received by the light receiving element a before being sufficiently spread. Therefore, the amount of light received by the light receiving element a is sufficiently large, and there is little risk of erroneous detection. On the other hand, when the light emitting element A and the light receiving element a are separated as shown in (3), the light is sufficiently spread at the position where the light emitted from the light emitting element A reaches the light receiving element a. In addition, the amount of light received by the light receiving element a is weak.

If the setting is made such that even weak light is turned on, other light may be turned on even if the object 1 is present between them, and there is a risk of erroneous detection. To prevent this, a light emitting element and a light receiving element having a narrow directivity are used. Therefore, an expensive light emitting / light receiving element must be used, and especially in the case of a device using a large number of light emitting elements, High cost. An infrared light emitting diode is used as the light emitting element, and a photodiode is used as the light receiving element.

When a light emitting element or a light receiving element which is inexpensive and has a poor directivity is used, the following problems occur. FIG. 6 shows that the light sensor S1 including the light emitting element A and the light receiving element a is adjacent to
Another light emitting element B and another light receiving element b are arranged. Therefore, when the object 1 is at the position shown by the solid line,
Since nothing exists in the optical paths of both light emitting elements A and B, the light receiving element receives both a and b, and is in the ON state.

Now, when the object 1 shown by the solid line moves in the direction of the arrow a ₁ and reaches the position of the chain line, the light emitted from the light emitting element A is blocked and the light receiving element a becomes unreceivable. It is detected that the 1 has come to the position. Object 1
Is further moved in the same direction and reaches the position indicated by the broken line, the light emitted from the light emitting element B is also blocked, and the light receiving element b cannot receive light, so that it is detected that the object 1 has reached the position. To be done.

Thus, whether the object 1 is in the position,
To detect whether it is in position, two sets of optical sensors S1,
S2 is required. In the case of a light emitting element that is inexpensive and has poor directivity, as shown in FIG. 7, the divergence angle θ of the emitted lights La and Lb from the light emitting elements A and B is large, and the light receiving element a,
As indicated by φ, b also has a spread in the light receiving region.

Therefore, as shown by the chain line, although the object 1 has passed through the optical axis position between the light emitting element A and the light receiving element a and has reached the position, the light emitted from the adjacent light emitting element B is , Is received by the light receiving element a at the position. as a result,
The light receiving element a determines that the object 1 has not arrived at the position, and makes an erroneous detection. Problems like this
The smaller the distance d from the position, the more likely it is to occur.

If the two sets of optical sensors S1 and S2 are arranged adjacent to each other, the above-mentioned problem occurs. Therefore, in FIG. 8, the optical axes of the light emitting element A and the light receiving element a are horizontal. Thus, the light emitting element B and the light receiving element b are arranged at the positions so that the optical axes are vertical.

[0012]

Thus, when the light emitting elements A and B are arranged so that their optical axes are orthogonal to each other,
Even if the directivity of the light emitting elements A and B and the light receiving elements a and b is wide, the light emitted from the light emitting element A in the horizontal direction is incident on the light receiving element b in the vertical direction or from the light emitting element B in the vertical direction. Since the emitted light does not enter the light receiving element a in the horizontal direction, there is no risk of erroneous detection.

When two sets of optical sensors S1 and S2 are mounted adjacent to each other as shown in FIG. 6, the light emitting elements A and B of both optical sensors are mounted in a common holder, and the light receiving elements a and b are also common. Can be mounted on the holder h. On the other hand, when the configuration is such that they are arranged orthogonally as shown in FIG. 8, the respective elements A, a,
Since B and b must be attached to different holders, the structure becomes complicated and the alignment between the respective elements is difficult. Further, since the light emitting element B and the light receiving element b are arranged in the vertical direction, the size in the height direction of the device becomes large, which hinders miniaturization.

The technical problem of the present invention is to pay attention to such a problem, and in a multi-type optical sensor for detecting two or more positions by using a plurality of optical sensors, even an inexpensive element having bad directivity is used. It is to be able to detect the position with high accuracy and to be mounted so that the optical axes of all the light emitting / receiving elements are parallel to each other.

[0015]

FIG. 1 is a diagram for explaining the basic principle of a multi-type photosensor according to the present invention. In each figure, the capital letters in Roman letters indicate the light emitting element side, and the letters in Roman letters indicate the light receiving element side. The light emitting element A and the light receiving element a, which are arranged to face each other, constitute an optical sensor S1, and the other light emitting element B and the light receiving element b form another optical sensor S.
Make up 2. Two or more sets of optical sensors each including a pair of such a light emitting element and a light receiving element are provided, S1, S2 ...
It constitutes a multi-type optical sensor.

According to the invention of claim 1, in such a multi-type optical sensor, as shown in (1), the light emitting element A and the light receiving element b of the adjacent optical sensors S1 and S2 are arranged adjacent to each other. , The light emitting elements A and B of the adjacent optical sensors S1 and S2,
The light receiving elements a and b are not adjacent to each other.

According to a second aspect of the present invention, as shown in (2), light-shielding members 6 and 7 are interposed between the light emitting element A and the light receiving element b of the adjacent optical sensors S1 and S2 in the first aspect. It is a composition.

According to a third aspect of the invention, as shown in (3), the light emitting element A and the light receiving element b of the adjacent photosensors S1 and S2 in the first aspect of the invention emit light emitted from the light emitting elements A and B. The configuration is such that they are displaced in the optical axis direction.

According to a fourth aspect of the present invention, as shown in (4), the optical axes of the light emitting elements of the plurality of optical sensors S1, S2, ... Of the first, second, and third aspects are orthogonal to each other. As described above, a large number are arranged.

[0020]

According to the present invention, the light emitting element A and the light receiving element b of the adjacent optical sensors S1 and S2 are arranged adjacent to each other, and the light emitting elements A and B of the adjacent optical sensors S1 and S2 are connected to each other. Since the light receiving elements a and b are not adjacent to each other, the light La emitted from the light emitting element A of the upper photosensor S1 in the figure has a spread such as θ and is incident on the element B adjacent to the light receiving element a. However, since the element B is a light emitting element, the problem of erroneous detection does not occur. Even if the light emitted from the light emitting element B of the optical sensor S2 enters the light emitting element A adjacent to the corresponding light receiving element b, there is no problem at all.

Therefore, according to the present invention, even if the directivity of the light emitting elements A and B and the light receiving elements a and b is bad, there is no fear of erroneous detection and an inexpensive element can be used. Further, since the light emitting element A and the light receiving element b of the adjacent optical sensors S1 and S2 are adjacent to each other, they can be mounted on the common holder h1, and the structure is simplified and high in the same manner as the conventional structure shown in FIG. A thin structure can be realized by reducing the dimension in the depth direction.

(1) As shown in FIG.
Even if the light emitting element A and the light receiving element b of S2 are arranged adjacent to each other, the weak light 8 leaks laterally from the light emitting element A.
If the light receiving element b and the light receiving element b are arranged in close contact with each other, the leaked light 8 may enter the light receiving element b on the side of the optical sensor S2 and may be erroneously detected.

On the other hand, as described in claim 2, the light emitting element A (B) and the light receiving element b (a) of the adjacent optical sensors S1 and S2 are arranged.
When the light shield 7 (6) is interposed between
Since the leakage light from B to the light receiving elements b and a is blocked,
There is no risk of false detection. Therefore, the adjacent light emitting element A
(B) and the light receiving element b (a) can be arranged in close contact with each other, and as a result, it is possible to reduce the distance d between the detection positions in FIGS. 6 to 8 and perform highly accurate position detection.

As in claim 3, adjacent optical sensors S1,
When the light emitting element A of S2 and the light receiving element b are arranged so as to be displaced in the optical axis Ia direction of the light emitting elements A and B, the light emitting element A
The leaked light 8 in the horizontal direction emitted from cannot enter the receivable area φ of the light receiving element b. Therefore, also in this case, even if the light emitting element A (B) and the light receiving element b (a) of the adjacent photosensors S1 and S2 are arranged close to each other, there is no risk of erroneous detection.

When a large number of optical sensors according to claim 1 or claim 2 and claim 3 are arranged so that the optical axes of the respective light emitting elements are orthogonal to each other, as in claim 4, the optical axis Ix in the lateral direction is obtained. If you insert a finger or the like at the intersection of the optical axis Iy in the vertical direction, the light in the horizontal and vertical directions at the intersection is blocked by your finger.
The position (coordinates) of inserting a finger etc. can be detected.

Further, according to the second and third aspects, it is possible to prevent the leaked light from the light emitting elements of the adjacent photosensors S1 and S2 from entering the adjacent photodetector, so that the photosensors S1 and S2 in the vertical direction can be prevented. It is possible to narrow the pitch of the optical axis and improve the position detection accuracy by making the distance between and the distance between the optical sensors S1 and S2 in the lateral direction close.

[0027]

EXAMPLES Next, examples of practical application of the multi-type photosensor according to the present invention will be described. FIG. 2 is a perspective view showing an embodiment of the invention of claim 1 corresponding to FIG. This embodiment is for detecting whether or not the object 1 has come to a position and whether it has come to a position, and is an example of detecting two positions.

Therefore, the light emitting element A of one optical sensor S1
The light-receiving element b of the other optical sensor S2 is disposed adjacent to, and is mounted on the common holder h1. Further, the light emitting element B of the other optical sensor S2 is arranged adjacent to the light receiving element a of one optical sensor S1 and mounted on the common holder h2.

In the conventional structure shown in FIG. 6, as described with reference to FIG. 7, even if the object 1 passes through the optical axis position of the light emitted from the light emitting element A of the one optical sensor S1, the light emitting element B from the adjacent light emitting element B will pass. Since the emitted light of ## EQU1 ## is incident on the light receiving element a of the optical sensor S1, it may be erroneously detected. However, in the configuration of FIG. 2, the light receiving element b is located at the position of the light emitting element B of FIG. Light receiving element a
Since only the light from the corresponding light emitting element A is incident on, there is no risk of erroneous detection.

However, if the light emitting element A and the light receiving element b are too close to each other, weak leak light in the lateral direction from the light emitting element A may enter the light receiving element b and cause erroneous detection. In a device having a small d, a light shielding plate or the like is provided between the light emitting element A and the light receiving element b and between the light emitting element B and the light receiving element a to physically block the leaked light. Is effective.

Alternatively, as in claim 3, the light emitting element A and the light receiving element b of the adjacent optical sensors S1 and S2 may be displaced in the optical axis direction, or the light emitting element B and the light receiving element a may be displaced in the optical axis direction. Good.

FIG. 3 shows an embodiment of the invention of claim 3. In FIG. 1 (3), the light emitting elements A and B are shifted rearward from the light receiving elements b and a of the adjacent photosensors, but in FIG. 3 (1), the light receiving elements b and a are respectively reversed. The arrangement is set back from the adjacent light emitting elements A and B. As described above, when the adjacent light receiving element b is retracted from the light emitting element A, the leaked light 8 emitted from the light emitting element A does not illuminate the rear side of the light emitting element A. There is no possibility that leaked light may be incident on b and may be erroneously detected.

In both (3) of FIG. 1 and (1) of FIG. 3, the distance D between the light emitting elements A and B and the light receiving elements a and b facing each other is constant in all the optical sensors S1 and S2. On the other hand, as shown in FIG. 3 (2), the distance between the light emitting element A (B) and the light receiving element a (b) of the adjacent optical sensors S1 and S2 is changed to change the light emitting / receiving element of the optical sensor S1. Adjacent photosensors from distance D1
The adjacent light emitting element A (B) and the light receiving element b (a) can also be shifted in the optical axis direction by reducing (or increasing) the light emitting / light receiving element spacing D2 of S2.

FIG. 4 (1) is an example in which the invention of claim 4 is applied to a screen touch switch, and FIG. 4 (2) is a view showing a conventional screen touch switch. (2) As shown in the figure, in the conventional screen touch switch, the light emitting elements A ... Z whose optical axes are in the lateral (X) direction are arranged adjacent to each other, and the light receiving elements a ... Z are the light emitting elements A. It is arranged so as to correspond to Z in a one-to-one correspondence. Even when the optical axis is in the vertical (Y) direction, the light emitting elements A ... Z are arranged adjacent to each other, and the light receiving elements a are arranged on opposite sides.
... z are arranged so as to correspond to the light emitting elements A ... Z in a one-to-one relationship.

Therefore, for example, the light emitted from the light emitting elements A and C is incident not only on the light receiving elements a and c facing each other but also on the adjacent light receiving element b, so that, for example, between the horizontal direction B-b and the vertical direction. Even if the position 9 between B and b is touched with a finger to block the light emitted from the light emitting devices B and B, the light emitted from the light emitting devices A and C is incident on the light receiving devices b and b. It will be determined that the intersection of −b and B−b on the side is not touched, resulting in an erroneous detection.

On the other hand, according to the idea of claim 1, in both the vertical and horizontal directions in FIG. 1A, the light emitting elements of the adjacent photosensors S1 and S2 are arranged so as not to be adjacent to each other, that is, the adjacent photosensors.
The light emitting element A and the light receiving element b of S1 and S2 are arranged adjacent to each other. As a result, for example, even when the light emitted from the lateral light emitting elements A and C is incident on the element B adjacent to the light receiving elements a and c facing each other, since the element B is a light emitting element, the light emitting elements A and C emit light. The emitted light of does not enter the other light receiving element.

As a result, when the intersection 9 of B-b and B-b is touched with a finger, only the light emitted from the light-emitting elements B, B facing each other is incident on the light-receiving elements b, b in the vertical and horizontal directions. Therefore, when the intersection point 9 of B-b and B-b is touched with a finger, light from the light-emitting elements B and the light-emitting elements other than B is not received, and the light passing through the position 9 is blocked. hand,
The corresponding light receiving elements b, b cannot receive light, and the touch position can be accurately detected.

In the illustrated embodiment, the light emitting element A and the light receiving element b which are adjacent to each other are displaced in the optical axis direction according to the concept of claim 3. That is, in the figure, the light receiving elements a, b ...
Are arranged so as to recede from the light emitting elements A, B, ....

Therefore, the leaked light in the lateral direction from each of the light emitting elements A, B, ... Is unlikely to be incident on the adjacent light receiving element b in the rear, and the leaked light from the light emitting element A adjacent to the light receiving element b. Therefore, there is no danger of false detection. Therefore, the arrangement pitch of the adjacent optical sensors S1, S2, ... Can be reduced to improve the accuracy of position detection.

[0040]

According to the first aspect of the present invention, since the light emitting elements A, B ... Are not adjacent to each other between the adjacent optical sensors S1 and S2 in the multi-type optical sensor, the light receiving elements a and b are not adjacent to each other.
Since only the light receiving elements b and a are present on both sides of the light emitting elements A and B in front of, the light from the light emitting elements other than the facing light emitting elements A and B is incident on the light receiving elements b and a, and erroneous detection is performed. Will not cause.

As a result, there is no risk of erroneous detection even if an inexpensive light emitting / receiving element having bad directivity is used. Further, since the light emitting element A and the light receiving element b can be arranged adjacent to each other, the light emitting element A and the light receiving element b can be mounted on the common holder h1, and as shown in FIG. 8, two sets of optical sensors are arranged orthogonally. The structure can be simplified as compared with, and the size in the height direction can be thinned to downsize the device.

According to claim 2, adjacent optical sensors S1,
The light shield 7 (6) is interposed between the light emitting element A (B) and the light receiving element b (a) of S2, and the leakage light 8 in the lateral direction from the adjacent light emitting elements A and B is blocked. Therefore, erroneous detection can be prevented more reliably, and adjacent optical sensors S1 and S2 can be arranged close to each other to improve the position detection accuracy.

According to the third aspect, since the light emitting element A and the light receiving element b which are adjacent to each other are arranged so as to be shifted in the optical axis direction of the light emitting element, the leak light 8 in the lateral direction from the adjacent light emitting elements A and B is arranged.
The light receiving elements b and a are located at positions that cannot be reached. Therefore, even if the distance d between the light emitting element A and the light receiving element b adjacent to each other is small, there is no risk of erroneous detection. As described above, the detection position accuracy is improved and the structure is simple without interposing a light shield. Be converted.

According to claim 4, a large number of optical sensors S1, S2
Are arranged so that their optical axes are orthogonal to each other, and when the idea of claim 1 is implemented in a device for detecting a coordinate position, light emission other than the light emitting elements A, B ... The light from the element is no longer received, and erroneous detection can be prevented. Moreover, when the idea of claims 2 and 3 is implemented and the pitch between the adjacent light emitting element A and light receiving element b is reduced,
The detection accuracy of the coordinate position can be improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a basic principle of a multi-type optical sensor according to the present invention.

FIG. 2 is a perspective view showing an embodiment of the invention of claim 1;

FIG. 3 is a diagram showing an embodiment of the invention of claim 3;

FIG. 4 is a diagram showing an example in which the invention of claim 4 is applied to a screen touch switch and a conventional screen touch switch.

FIG. 5 is a side view showing the optical sensors classified according to the arrangement format.

FIG. 6 is a perspective view showing a usage state of a conventional multi-type optical sensor.

FIG. 7 is a diagram illustrating directional characteristics of a light emitting element and a light receiving element.

FIG. 8 is a perspective view of a conventional configuration in which two sets of optical sensors are orthogonally arranged.

[Explanation of symbols]

 A, B ... Light emitting element a, b ... Light receiving element 1 Object (object to be detected) 2, 3, 4, 5 Holder h, h1, h2 Holder 6, 7 Light shield 8 Leakage light from light emitting element 9 Touch position

Claims (4)

[Claims] 1. A light emitting element and a light receiving element are arranged to face each other,
The light emitted from the light emitting element is received by the light receiving element, and when the object enters in between, the light receiving element cannot receive light,
In a multi-type optical sensor in which two or more sets of transmissive optical sensors for detecting the presence or absence of an object are arranged adjacent to each other, the light emitting element A and the light receiving element b of the adjacent optical sensors S1 and S2 are arranged adjacent to each other. The adjacent optical sensors S1 and S2
2. The multi-type optical sensor, wherein the light emitting elements A and B are not adjacent to each other and the light receiving elements a and b are not adjacent to each other. 2. The adjacent optical sensor S1 according to claim 1,
A multi-type optical sensor, characterized in that a light shield 7 (6) is interposed between the light emitting element A (B) and the light receiving element b (a) of S2. 3. The adjacent optical sensor S1 according to claim 1,
A multi-type optical sensor in which the light emitting element A and the light receiving element b of S2 are arranged so as to be offset from each other in the optical axis direction of the light emitted from the light emitting elements A and B. 4. A multi-sensor comprising a plurality of photosensors S1, S2, ... According to claim 1, 2 or 3, wherein a plurality of photosensors S1, S2, ... Are arrayed so that the optical axes of the respective light emitting elements are orthogonal to each other. Optical sensor.