JP2007071564A - Optical tactile proximity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To closely arrange detection positions with a fine pitch, to detect the force received from an external object and the proximity of the object with high accuracy, to be simple in configuration, and to reduce the cost. An optical tactile proximity sensor is provided.
When a force acting from the outside is detected, a first light emitting diode L1 of two adjacent light emitting diodes is set in a light emitting mode, and a second light emitting diode L2 is set in a light receiving mode. The light receiving amount I1 of the light emitting diode L2 is measured. Next, the first light emitting diode L1 is switched to the light receiving mode, and the second light emitting diode L2 is switched to the light emitting mode. In this state, the light receiving amount I2 of the first light emitting diode L1 is measured. Then, the magnitude F of the force acting on the light propagation layer 3 or its position x is calculated based on the received light amounts I1 and I2 of the second and first light emitting diodes L2 and L1.
[Selection] Figure 7

Description

  The present invention relates to an optical tactile proximity sensor that detects a force received from a contacted object and proximity of the object.

  Execution of autonomous work by the robot is performed based on a series of work procedures given to the robot. In this execution, a sensor that recognizes an object in contact with or close to each part of the robot and detects the force received from the object and the proximity of the object is essential for the robot. Hereinafter, such a sensor is referred to as a “tactile proximity sensor” in the present application.

Conventional tactile proximity sensors can be broadly classified into tactile sensors and proximity sensors.
A tactile sensor is a sensor that is used in, for example, a robot hand and detects a force acting between a finger and an object when the object is gripped by the hand. Detection and identification.
On the other hand, a proximity sensor is a sensor that detects the approach of a target object in a non-contact manner, and detects the position of a nearby object, the distance to the object, and the like.

An optical tactile sensor is described in Patent Document 1, for example.
As shown in FIG. 19A, a sensor 30 described in Patent Document 1 includes an optical fiber 32 for light emission, an optical fiber 34 for light reception, and a scattering medium 36 in which these optical fibers are embedded. Have
As shown in FIG. 19B, this scattering medium 36 is compressed and deformed when an external force is applied, and its scattering characteristics change. Thereby, since the scattering of the light emitted from the optical fiber 32 for light emission changes, the amount of light received detected by the optical fiber 34 for light reception also changes. Therefore, the magnitude of the force acting on the scattering medium can be estimated by measuring the change in the amount of received light detected by the light receiving optical fiber 34.

US Pat. No. 5,917,180 “PRESSURE SENSOR BASED ON ILLUMINATION OF A DEFORMABLE INTEGRATING CAVITY”

  The optical tactile sensor of Patent Document 1 requires a light emitting element and a light receiving element which are connected to the optical fiber 32 for light emission and the optical fiber 34 for light reception, which are separated from each other. Therefore, when a plurality of light emitting optical fibers 32 and a plurality of light receiving optical fibers 34 are closely arranged at a fine pitch, a light emitting element circuit network for selectively operating a plurality of light emitting elements And a circuit network for the light receiving elements for selectively operating the plurality of light receiving elements.

  Therefore, not only the circuit network for the light emitting element but also the circuit network for the light receiving element must be provided, and the configuration becomes complicated accordingly. Furthermore, since the light receiving element (for example, photodiode) is usually more expensive than the light emitting element (for example, light emitting diode), the cost of the tactile sensor is inevitably high.

Therefore, it is desirable to be able to arrange the detection positions densely at a fine pitch, simplify the configuration of the tactile sensor, and reduce its cost. There is also a need for a more accurate tactile sensor.
Similarly, in the case of a proximity sensor, it is desirable that detection positions can be densely arranged with a fine pitch, that the configuration is simple, and that the cost can be reduced.

  The present invention has been developed to meet the above-described problems. That is, the object of the present invention is that the detection positions can be densely arranged at a fine pitch, the force received from an external object and the proximity of the object can be accurately detected, the configuration is simple, and the cost is low. It is an object of the present invention to provide an optical tactile proximity sensor capable of reducing the above.

  In order to achieve the above object, according to the first invention, there is provided an optical tactile proximity sensor for detecting a force acting from the outside, and a plurality of light emitting diodes arranged at intervals from each other, and each light emitting diode emits light. Switching means for switching between the mode and the light receiving mode, and the light from the light emitting diode in the light emitting mode is propagated to the light emitting diode in the light receiving mode, and the light propagation characteristics are changed by compressing and deforming by the external force. A light propagation medium, a measurement means for measuring the amount of light received by the light emitting diode in the light reception mode, and a calculation means for calculating the magnitude or position of the force acting on the light propagation medium based on the measured light reception amount A part of the plurality of light emitting diodes is set to a light emitting mode, a part adjacent to the light emitting diode is set to a light receiving mode, It calculates the magnitude or position of the force acting on the light propagation medium, the optical tactile proximity sensor, characterized in that are provided Zui.

  According to the second invention, in the first invention, when detecting the force acting from the outside, the switching means sets the first light emitting diode in the light emitting mode among the two adjacent light emitting diodes to the second light emitting diode. In this state, the measuring means measures the amount of light received by the second light emitting diode, and the calculating means acts on the light propagation medium based on the amount of light received by the second light emitting diode. Calculate the magnitude of the force or its position.

  According to a third invention, in the second invention, the switching means sequentially selects and switches a light emitting diode to be set to a light emitting mode and a light emitting diode to be set to a light receiving mode from a plurality of light emitting diodes. In addition, the measuring means measures the amount of light received by the light emitting diode set in the light receiving mode, and the computing means calculates the magnitude of the force acting on the light propagation medium or its position based on the amount of received light.

  According to a fourth invention, in the first invention, when detecting the force acting from the outside, the switching means sets the first light emitting diode of two adjacent light emitting diodes to the light emitting mode, and sets the second light emitting diode. In this state, the measuring means measures the amount of light received by the second light emitting diode, and then the switching means sets the first light emitting diode to the light receiving mode and the second light emitting diode to the light emitting mode. In this state, the measuring means measures the amount of light received by the first light emitting diode, and the computing means is a force acting on the light propagation medium based on the amount of light received by the first and second light emitting diodes. Is calculated or its position.

  According to a fifth invention, in the fourth invention, the switching means sequentially selects a light emitting diode to be operated from a plurality of light emitting diodes, and each time the switching means selects the light emitting diode in an operating state. Among them, the first light emitting diode is set to the light emitting mode and the second light emitting diode is set to the light receiving mode. In this state, the measuring means measures the amount of light received by the second light emitting diode, and then the switching means The first light emitting diode is switched to the light receiving mode, and the second light emitting diode is switched to the light emitting mode. In this state, the measuring means measures the amount of light received by the first light emitting diode, and the computing means measures these. The magnitude of the force acting on the light propagation medium or its position is calculated based on the received light amount.

  According to a sixth invention, in the first invention, the plurality of light emitting diodes are disposed on an upper surface of the substrate, and the light propagation medium is disposed on an upper surface side of the substrate so as to sandwich the plurality of light emitting diodes with the substrate. It is formed as a light propagation layer.

  According to a seventh aspect, in the sixth aspect, the upper surface of the light propagation layer is covered with an opaque coat.

  According to an eighth invention, in the third invention, an opaque layer is provided around each side of the plurality of light emitting diodes.

  According to a ninth invention, in the fourth invention, the light propagation medium includes a light propagation characteristic from the first light emitting diode to the second light emitting diode, and the second light emitting diode to the second light emitting diode. A physical structure is incorporated so as to increase the difference from the light propagation characteristics to one light emitting diode.

  According to the tenth invention, an optical tactile proximity sensor for detecting the approach of an object, wherein a plurality of light emitting diodes arranged at intervals from each other, and a light emitting mode and a light receiving mode are set from the plurality of light emitting diodes. Switching means for selecting a light emitting diode and setting the mode of the light emitting diode so that the light emitting diode set in the light receiving mode receives light emitted from the light emitting diode set in the light emitting mode and reflected by the object; An optical system comprising: a measuring means for measuring the amount of light received by the light emitting diode set in the light receiving mode; and a detecting means for detecting the approach of an object based on the measured amount of received light. A tactile proximity sensor is provided.

  According to the eleventh invention, when detecting the approach of the object, the switching means sequentially selects a light emitting diode to be set to the light emitting mode and a light emitting diode to be set to the light receiving mode from a plurality of light emitting diodes. Each time the measuring means measures the amount of light received by the light emitting diode set in the light receiving mode, the detecting means detects the approaching position of the object based on the amount of received light.

  In the first and tenth aspects, a plurality of mode-switchable light-emitting diodes are arranged, and the position of the light-emitting diodes switched to the light-receiving mode becomes the detection position. Therefore, the position of all the light emitting diodes can be set as the detection position by mode switching. Therefore, the detection positions can be densely arranged at a fine pitch. Further, it is not necessary to separately provide a circuit network for a plurality of light-emitting elements and a circuit network for a plurality of light-receiving elements, and only a circuit network for light-emitting diodes capable of mode switching needs to be provided, thereby simplifying the configuration. . Furthermore, since the light emitting diode is provided so that the mode can be switched without providing an expensive light receiving element for light reception, the cost can be reduced.

  In the second and third inventions, since the light emitting diode set to the light emitting mode and the light emitting diode set to the light receiving mode are selected from the plurality of light emitting diodes and the force acting on the tactile proximity sensor is detected, the tactile proximity sensor It is possible to detect forces acting at a plurality of locations.

  In the fourth and fifth inventions, when detecting the force acting on the tactile sensor, the first and second light emitting diodes are switched so that the modes are opposite to each other. The magnitude of the force acting on the light propagation medium and its position are calculated based on the amount of light received by both of the light emitting diodes. Thereby, both the magnitude | size of the force which acts on a light propagation medium, and its position can be calculated | required.

  In the sixth aspect of the invention, a plurality of light emitting diodes are arranged on the substrate, and the light propagation medium is formed on the upper surface of the substrate as a layer, so that a compact tactile proximity sensor can be realized.

  In the seventh aspect, since the upper surface of the light propagation layer is covered with the opaque coat, the influence of light from the outside can be prevented.

  In the eighth aspect, the opaque layer provided around the side of the light emitting diode can prevent the influence of stray light on the amount of light received by the light emitting diode.

  In the ninth aspect of the invention, the physical structure incorporated in the light propagation medium allows the light propagation characteristics from the first light emitting diode to the second light emitting diode and the first light emission from the second light emitting diode. Since the difference from the propagation characteristics of light to the diode becomes large, the detection accuracy is increased.

  In the eleventh aspect of the invention, an object approaching the tactile proximity sensor is detected while sequentially selecting and switching a light emitting diode set to the light emitting mode and a light emitting diode set to the light receiving mode from a plurality of light emitting diodes. It is possible to detect the approach of the object at a plurality of locations of the proximity sensor.

  In short, according to the present invention, the detection positions can be densely arranged at a fine pitch, the force received from an external object and the proximity of the object can be detected with high accuracy, and the configuration becomes simple. Cost can be reduced.

  A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1A is a perspective view showing a configuration of a tactile proximity sensor 10 according to an embodiment of the present invention, and FIG. 1B is a sectional view thereof.

  The tactile proximity sensor 10 includes a substrate 2, a plurality of light emitting diodes (LEDs) L <b> 1, L <b> 2,. A light propagation layer 3 formed on the upper surface side of the substrate 2 and a surface coat 4 formed on the upper surface of the light propagation layer 3.

  According to an embodiment of the present invention, the light propagation layer 3 is a light propagation medium that is a translucent electrical insulator. Further, the light propagation layer 3 is compressed and deformed by a force acting from the outside, thereby changing the light propagation characteristics. In the embodiment of the present invention, the light propagation layer 3 changes light propagation characteristics such as light absorption characteristics, light scattering characteristics, and light reflection characteristics when compressed and deformed. Such a light propagation layer 3 is, for example, sponge, polystyrene foam, gel, rubber or the like, but the present invention is not limited to this, and light compression characteristics such as light absorption characteristics, light scattering characteristics, and light reflection characteristics when compressed and deformed. Other suitable ones whose characteristics change may be used.

  The surface coat 4 formed on the upper surface of the light propagation layer 3 is made of an opaque material. Thereby, the influence of the light from the outside can be prevented.

  Further, an opaque layer 6 is provided around each side portion of the plurality of light emitting diodes L1, L2,... Ln arranged on the substrate 2. Thereby, when the light emitting diode is switched to the light receiving mode as will be described later, the influence of stray light on the amount of light received by the light emitting diode can be prevented.

  The substrate 2 may be, for example, a rigid printed circuit board (PCB) or a flexible printed circuit board. A circuit network for operating the light emitting diodes L1, L2,... Ln is formed on the substrate 2. FIG. 2 shows this network for operating each light emitting diode by addressing. That is, lines x1, x2,... Xn and lines y1, y2... Yn are provided to selectively operate the light emitting diodes L1, L2,.

The mode switching of the light emitting diode will be described by paying attention to one of the plurality of light emitting diodes L1, L2,... Ln shown in FIGS. FIG. 3 shows the mode switching circuit 8 including the lines x1 and y3 of the light emitting diode L1 shown in FIG. When the switches SW1 and SW2 are switched, the light emitting diode L1 is switched between the light emitting mode and the light receiving mode. That is, as in FIG. 3 (A), connected switch SW1 through a resistor R _F in the voltage V +, the switch SW2 is connected to 0V, and the light emitting diode L1 emits light becomes luminous mode. On the other hand, as shown in FIG. 3 (B), the switch SW1 through a resistor RL is connected to 0V, and the switch SW2 is connected to the voltage V _R, the light emitting diode L1 is its conductivity in accordance with the received light amount becomes receiving mode To change.

In the example of FIG. 3, the light receiving mode of the light emitting diode L1 is a photoconductive type, but the light emitting diode L1 may be configured so that the light receiving mode is a photovoltaic type.
FIG. 4 shows a circuit when the light receiving mode of the light emitting diode L1 is photovoltaic. In FIG. 4, when the switches SW1 and SW2 are switched, the light emitting diode L1 is switched between the light emitting mode and the light receiving mode. That is, as in FIG. 4 (A), connected switch SW1 through a resistor R _F in the voltage V +, the switch SW2 is connected to 0V, and the light emitting diode L1 emits light becomes luminous mode. On the other hand, as shown in FIG. 4B, when the switch SW1 is connected to 0V and the switch SW2 is disconnected from 0V, the light emitting diode L1 enters the light receiving mode and changes its electromotive force according to the amount of received light.

  3 and 4, Vout is connected to a dedicated operational amplifier (not shown), for example. 3 and 4 show the case of the light emitting diode L1, but the mode switching circuit 8 similar to that of FIGS. 3 and 4 is connected to each of the other light emitting diodes L2,... Ln shown in FIG. ing. Each of the light emitting diodes is selected by selecting lines x1, x2,... Xn, lines y1, y2... Yn and operating switches SW1 and SW2 under the control of a microprocessor (not shown). L1, L2,... Ln are set to the light emission mode or the light reception mode and selectively operated. In this manner, the tactile proximity sensor 10 can be configured such that selection of the light emitting diode to be operated and mode switching of the selected light emitting diode are controlled by the microprocessor. The mode switching circuit 8 and the microprocessor constitute switching means for switching the mode of the light emitting diode, but the switching means may be constituted by other appropriate devices having the same function.

  Next, the operation of the tactile proximity sensor 10 having the above-described configuration will be described.

In order to detect the force acting on the light propagation layer 3 of the tactile proximity sensor 10, the light emitting diode L1 in FIG. 2 is set to the light emitting mode, and the surrounding light emitting diodes L2 and L4 are set to the light receiving mode. Specifically, connected to the voltage V + of the switch SW1 of the line x1 through the resistor _{R F,} the switch SW2 of the line y3 connected to 0V, thereby setting the light-emitting diodes L1 to the light emitting mode. Then, the switch SW1 of the line x2 through the resistor RL is connected to 0V, and the switches SW2 of the line y2, y4 connected to _{V R,} sets the light-emitting diode L2, L4 to the light-receiving mode.

  As shown in FIG. 5, when the force F acts on the light propagation layer 3 between the light emitting diodes L1 and L2, the light propagation layer 3 is compressed and deformed. The light propagation characteristics such as the light absorption characteristic and the light scattering characteristic are changed as compared with the case where the film is not compressed and deformed. As the light propagation characteristic changes, the amount of light radiated from the light emitting diode L1 reaches the light emitting diode L2 also changes, so that the amount of received light I1 of the light emitting diode L2 also changes. This change in the amount of received light I1 is read out as an electric signal Vout. Therefore, by measuring the change amount of the electric signal, the magnitude of the force acting on the light propagation layer 3 and its position can be calculated. Note that the measuring means for reading the electric signal Vout and measuring the amount of received light I1 can be configured by an appropriate device. In addition, it is possible to configure an arithmetic unit that performs the above calculation using an appropriate device.

  FIG. 6 shows data obtained by experiment for the amount of received light I1 of the light emitting diode L2 in the case of FIG. In this figure, the horizontal axis indicates the force acting on the surface of the tactile proximity sensor 10, and the vertical axis indicates the amount of received light I1 of the light emitting diode L2 in the light receiving mode. As can be seen from FIG. 6, the amount of received light I1 decreases as the force acting on the tactile proximity sensor 10 increases. The sensitivity and detection range of the tactile proximity sensor 10 depend on a change in light propagation characteristics due to compression of the light propagation layer 3, a light emitting diode to be used, a layout of an LED circuit network, a drive circuit, and the like. Calculation of the magnitude and position of the force acting on the tactile proximity sensor 10 is performed by an interpolation method based on the data of FIG. 6 obtained in advance by experiments and the measured amount of received light I1 of the light emitting diode L2. be able to.

  When detecting the force acting on the tactile proximity sensor 10, the light emitting diodes L1, L2,... Ln are operated in order. That is, first, the light emitting diode L1 is set in the light emitting mode, the surrounding light emitting diodes L2 and L4 are set in the light receiving mode, the force acting on the vicinity of the light emitting diode L1 is detected, and then the next light emitting diode L2 is set in the light emitting mode. The light-emitting diodes L1, L3, and L5 are set in the light-receiving mode, and the force acting near the light-emitting diode L2 is detected. In this way, the force acting in the vicinity of each light emitting diode can be detected by sequentially switching the light emitting diodes to be in the light emitting mode.

In the tactile proximity sensor 10 according to the first embodiment described above, a plurality of mode-switchable light-emitting diodes L1, L2,... Ln are arranged, and the position of the light-emitting diode switched to the light-receiving mode becomes the detection position. In other words, since the positions of all the light emitting diodes can be set as the detection positions by the mode switching, the detection positions can be densely arranged at a fine pitch. Further, by switching the mode of the light emitting diode, an external force can be detected without using an expensive light receiving element dedicated to light reception, so that a tactile proximity sensor with a simple configuration and reduced cost can be realized.

  Next, a second embodiment of the present invention will be described. The configuration of the tactile proximity sensor according to the second embodiment is the same as that of the first embodiment, but the operation is different. Hereinafter, the operation of the tactile proximity sensor 10 according to the second embodiment will be described.

  According to the second embodiment, the detection accuracy can be increased by the two-step detection step. The light emitting diodes L1, L2,... Ln will be described by focusing on the light emitting diodes L1, L2, but the same applies to other light emitting diode pairs. Consider a case where a force F is applied to the position X as shown in FIGS.

  First, in the first step, as shown in FIG. 7, the light emitting diode L1 is set to the light emitting mode, and the light emitting diode L2 is set to the light receiving mode. This setting method is the same as that in the first embodiment. In this state, the light emitting diode L2 receives the light emitted from the light emitting diode L1 through the light propagation layer 3, and the received light amount I1 of the light emitting diode L2 is read as the electric signal Vout.

  Next, as shown in FIG. 8, in the second step, the light emitting diode L1 is switched to the light receiving mode, and the light emitting diode L2 is switched to the light emitting mode. In this state, the light emitting diode L1 receives the light emitted from the light emitting diode L2 through the light propagation layer 3, and the received light amount I2 of the light emitting diode L1 is read as the electric signal Vout.

  And the force which acts on the light propagation layer 3 is calculated | required based on light reception amount I1 of the light emitting diode L2, and light reception amount I2 of the light emitting diode L1. FIG. 9 shows how the received light amounts I1 and I2 change when the magnitude F of the force acting on the light propagation layer 3 and its position x change. That is, the curve I1 represents the light receiving amount I1 of the light emitting diode L2 when the light emitting diode L1 is in the light emitting mode and the light emitting diode L2 is in the light receiving mode, and the curve I2 is the light emitting diode L1 in the light receiving mode and the light emitting diode L2 in the light emitting mode. Represents the amount of light I2 received by the light emitting diode L1. If the data of FIG. 9 is obtained in advance by experiment, when the light receiving amount I1 of the light emitting diode L2 is i1 and the light receiving amount I2 of the light emitting diode L1 is i2 by the above-described two-step detection step. From the relationship shown in FIG. 9, it is detected that the position x of the force acting on the tactile proximity sensor 10 is X and the magnitude thereof is F = 4.

  10, 11, and 12, the light receiving amounts I1 and I2 of the respective light emitting diodes L2 and L1 were actually obtained by experiments at a large number of positions between the two light emitting diodes L1 and L2 for a number of different forces. Data are shown. In each figure, the horizontal axis indicates the position between the light emitting diodes L1 and L2 when the center of the light emitting diodes L1 and L2 is the origin, and the vertical axis indicates the amount of light received (light receiving intensity) I1 of the light emitting diodes L2 and L1. I2 is shown.

  The curve in FIG. 10 represents the relationship between the amount of light received by the light emitting diode L2, the magnitude F of the acting force, and the position x when the light emitting diode L1 is in the light emitting mode and the light emitting diode L2 is in the light receiving mode.

  The curve in FIG. 11 represents the relationship between the light receiving amount I2, the acting force magnitude F, and the position x of the light emitting diode L1 when the light emitting diode L1 is in the light receiving mode and the light emitting diode L2 is in the light emitting mode.

  FIG. 12 is a combination of the curve of FIG. 10 and the curve of FIG. 10, 11, and 12 are determined by the physical structure of the tactile proximity sensor 10, for example, the material of the light propagation layer 3, the physical structure incorporated in the light propagation layer 3 described later, and the like. .

  In order to approximate the data as shown in FIG. 12, for example, a multidimensional function approximation system such as an artificial neural network is used.

  Therefore, in the second embodiment, in order to detect the force acting on the tactile proximity sensor 10 from the outside, the received light amounts I1 and I2 of the light emitting diodes L2 and L1 are sequentially read out by the above-described two-step detection step, and these readouts are performed. Based on the received light amounts I1 and I2 and data obtained by experiments in advance as shown in FIG. 12, the magnitude and position of the force acting on the tactile proximity sensor 10 can be calculated by interpolation. As described above, based on both the received light amounts I1 and I2, the force acting on the tactile proximity sensor 10 and the two unknown amounts of the position where the force is acting can be obtained. Note that an arithmetic unit that performs this calculation can be configured by an appropriate device.

  Furthermore, according to the second embodiment, a physical structure may be incorporated in the light propagation layer 3 in order to obtain the operation described below.

  In the example of FIG. 13, the physical structure 12a is incorporated in the vicinity of the light emitting diode L1. The physical structure 12 a may be made of an opaque material having the same or different compressive deformation characteristics as the surrounding light propagation layer 3.

  In the example of FIG. 14, the physical structure 12b has a conical shape that is symmetrically incorporated in the center between the light emitting diodes L1 and L2. Also in the case of FIG. 14, the physical structure 12 b may be made of an opaque material having the same or different compressive deformation characteristics as the surrounding light propagation layer 3.

  In the example of FIG. 15, the physical structure is a reflective film 12 c having a high reflectivity and a reflective film 12 d having a low reflectivity incorporated in the upper part of the light propagation layer 3.

  By incorporating such a physical structure, the difference between the light propagation characteristic from the light emitting diode L1 to the light emitting diode L2 and the light propagation characteristic from the light emitting diode L2 to the light emitting diode L1 can be increased. That is, the curve representing the light receiving amount I1 of the light emitting diode L2 shown in FIG. 10 and the curve representing the light receiving amount I2 of the light emitting diode L1 shown in FIG. 11 are symmetric with respect to the straight line X = 0. By incorporating the physical structure into the light propagation layer 3 as shown in FIG. 15, a curve representing the amount of received light I1 of the light emitting diode L2 shown in FIG. 10 and a curve representing the amount of received light I2 of the light emitting diode L1 shown in FIG. The shape difference can be increased as asymmetric. By calculating the magnitude and position of the force acting on the tactile proximity sensor 10 based on the experimental data curve having such a large shape difference and the detected light receiving amounts I1 and I2, the accuracy of the calculated value is further increased. Can be increased.

  Next, a third embodiment of the present invention will be described. The sensor of the third embodiment is a tactile proximity sensor 20, and the configuration thereof is obtained by removing the light propagation layer 3 of the tactile proximity sensor 10 of the first embodiment as shown in FIG. In FIG. 16, a range indicated by a dotted line is a range in which the proximity of the object can be detected by the light emitting diodes L1, L2, and L3.

  The operation of the tactile proximity sensor 20 is performed as follows. First, one light emitting diode L1 among the plurality of light emitting diodes arranged on the substrate 2 is set in the light emitting mode, and the surrounding light emitting diode L2 is set in the light receiving mode. As shown in FIG. 17, when the object 22 is close to the light emitting diode L1, the light emitting diode L2 receives the light emitted from the light emitting diode L1 and reflected by the object 22. Therefore, it can be detected that the object 22 is close to the light emitting diode L1 based on the light received by the light emitting diode L2.

  According to the third embodiment, the light emitting diode L1 is first set in the light emitting mode, the surrounding light emitting diode L2 is set in the light receiving mode, and it is detected whether the object 22 is close to the light emitting diode L1, and then the light emitting diode. In order to detect whether the object 22 is close to the vicinity of the light emitting diode L2, the light emitting diodes to be set in the light emitting mode are switched in order so that L2 is set to the light emitting mode and the surrounding light emitting diode L3 is set to the light receiving mode. The surrounding light emitting diodes are switched to the light receiving mode. By this method, it is also possible to detect which light emitting diode is close to the object 22.

  FIG. 18 shows an embodiment of the tactile proximity sensor 20. The tactile proximity sensor 20 detects the position of the paper 24 in the copying machine, and a plurality of light emitting diodes L1, L2,... Ln are arranged on the substrate 2 in a straight line. The light emitting diode L1 is set in the light emitting mode, the light emitting diode L2 is set in the light receiving mode, and then the light emitting diode L2 is set in the light emitting mode and the light emitting diode L3 is set in the light receiving mode. Switch the light-emitting diode to be in mode.

  Thereby, for example, as shown in FIG. 18, when the leading end 24a of the paper 24 is close to the light emitting diode L2, a difference appears between the light receiving amount I1 of the light emitting diode L2 and the light receiving amount I2 of the light emitting diode L3. It can be detected that the leading end 24a of the sheet is close to the light emitting diode L2. Further, when the leading end 24a of the paper 24 is close to the light emitting diode L3, a difference appears between the light receiving amount I2 of the light emitting diode L3 and the light receiving amount I3 of the light emitting diode L4. Can be detected. In this way, it is possible to detect which light emitting diode is close to the leading edge 24a of the paper 24. In addition, the detection means which performs this detection with an appropriate apparatus can be comprised.

  Further, the position of the leading end 24a of the paper 24 can be detected with higher accuracy. When the leading end 24a of the sheet 24 is close to the light emitting diode L2, and when the leading end position of the sheet 24 is detected with higher accuracy, the calculation based on the received light amount I2 of the light emitting diode L3 is performed. Specifically, the light-emitting diode L2 is set in the light-emitting mode, the light-emitting diode L3 is set in the light-receiving mode, and the data of the light-receiving amount I2 of the light-emitting diode L3 is obtained by experiments in advance for a number of paper leading positions near the light-emitting diode L2. When the leading end position of the sheet 24 is actually detected, the leading end position of the sheet 24 is calculated by interpolation based on this data and the amount of received light I2 detected by the light emitting diode L3.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the plurality of light emitting diodes are arranged on the planar substrate 2, but may be arranged on a curved substrate.

It is a block diagram of the tactile proximity sensor by the 1st Embodiment of this invention. It is a figure which shows the circuit network for selectively operating the light emitting diode of FIG. It is a figure which shows the mode switching circuit of the light emitting diode of FIG. It is a figure which shows the mode switching circuit of the light emitting diode of FIG. It is explanatory drawing of operation | movement of the tactile proximity sensor of FIG. In FIG. 5, it is a figure which shows the relationship between the force which acts from the outside, and the light reception amount of a light emitting diode. It is a figure explaining operation | movement of the tactile proximity sensor by the 2nd Embodiment of this invention. It is a figure explaining operation | movement of the tactile proximity sensor by the 2nd Embodiment of this invention. It is a figure explaining the method of calculating the magnitude | size and position of the force which acts from the outside with the tactile proximity sensor by the 2nd Embodiment of this invention. It is a figure which shows the magnitude | size of the force which acts from the outside according to the 2nd Embodiment of this invention, its position, and the relationship of the light reception amount I1 of the light emitting diode L2. It is a figure which shows the magnitude | size of the force which acts from the outside by the 2nd Embodiment of this invention, its position, and the relationship of the light reception amount I2 of the light emitting diode L1. This is a combination of the data of FIG. 10 and FIG. It is a figure which shows the example which also incorporated the physical structure in the light propagation layer by the 2nd Embodiment of this invention. It is a figure which shows another example which also incorporated the physical structure in the light propagation layer by the 2nd Embodiment of this invention. It is a figure which shows another example which also incorporated the physical structure in the light propagation layer by the 2nd Embodiment of this invention. It is a figure which shows the structure of the tactile proximity sensor by the 3rd Embodiment of this invention. It is a figure explaining operation | movement of the tactile proximity sensor of FIG. It is a figure which shows the Example of the tactile proximity sensor by the 3rd Embodiment of this invention. It is a figure which shows the structure of the conventional tactile sensor.

Explanation of symbols

2 substrate, 3 light propagation layer, 4 surface coat 6 opaque layer, 8 mode switching circuit 10 tactile proximity sensor 12a, 12b, 12c, 12d physical structure 20 tactile proximity sensor 22 object, 24 paper, 24a paper leading edge L1, L2, ... Ln Light emitting diode

Claims (11)

An optical tactile proximity sensor that detects a force acting from the outside,
A plurality of light emitting diodes spaced apart from each other;
Switching means for switching and setting each light emitting diode between the light emitting mode and the light receiving mode;
A light propagation medium in which light from a light emitting diode in a light emitting mode is propagated to a light emitting diode in a light receiving mode, and the light propagation characteristic is changed by compressive deformation by a force acting from the outside;
Measuring means for measuring the amount of light received by the light emitting diode in the light receiving mode;
A calculation means for calculating the magnitude of the force acting on the light propagation medium or its position based on the measured amount of received light, and
A part of the plurality of light emitting diodes is set to a light emitting mode, a part adjacent to the light emitting diode is set to a light receiving mode, and the magnitude of the force acting on the light propagation medium based on the amount of light received by the light emitting diode in the light receiving mode Calculate its position,
An optical tactile proximity sensor. When detecting the force acting from the outside, the switching means sets the first light emitting diode in the light emitting mode and the second light emitting diode in the light receiving mode among the two adjacent light emitting diodes. The means measures the amount of light received by the second light emitting diode, and the calculation means calculates the magnitude of the force acting on the light propagation medium or its position based on the amount of light received by the second light emitting diode.
The optical tactile proximity sensor according to claim 1. The switching means sequentially selects and switches a light emitting diode to be set to the light emitting mode and a light emitting diode to be set to the light receiving mode from a plurality of light emitting diodes, and each time the measuring means is set to the light emitting mode set to the light receiving mode. The amount of light received by the diode is measured, and the calculation means calculates the magnitude of the force acting on the light propagation medium or the position thereof based on the amount of received light.
The optical tactile proximity sensor according to claim 2. When detecting the force acting from the outside, the switching means sets the first light emitting diode of two adjacent light emitting diodes to the light emitting mode and the second light emitting diode to the light receiving mode, and in this state, the measuring means Measures the amount of light received by the second light emitting diode,
Next, the switching means switches the first light emitting diode to the light receiving mode and the second light emitting diode to the light emitting mode, and in this state, the measuring means measures the amount of light received by the first light emitting diode,
The calculation means calculates the magnitude of the force acting on the light propagation medium or the position thereof based on the amount of light received by the first and second light emitting diodes.
The optical tactile proximity sensor according to claim 1. The switching means sequentially selects a light emitting diode to be operated from a plurality of light emitting diodes,
Each time, the switching means sets the first light emitting diode among the light emitting diodes in the operating state to the light emitting mode and the second light emitting diode to the light receiving mode, and in this state, the measuring means performs the second light emitting operation. The amount of light received by the diode is measured, and then the switching means switches the first light emitting diode to the light receiving mode and the second light emitting diode to the light emitting mode. Measure the amount of light received by the diode,
The calculation means calculates the magnitude of the force acting on the light propagation medium or the position thereof based on the measured amount of received light,
The optical tactile proximity sensor according to claim 4. The plurality of light emitting diodes are disposed on an upper surface of the substrate, and the light propagation medium is formed as a light propagation layer on the upper surface side of the substrate so as to sandwich the plurality of light emitting diodes with the substrate.
The optical tactile proximity sensor according to claim 1.   The optical tactile proximity sensor according to claim 6, wherein an upper surface of the light propagation layer is covered with an opaque coating.   The optical tactile proximity sensor according to claim 6, wherein an opaque layer is provided around each side portion of the plurality of light emitting diodes. The light propagation medium includes a difference between a light propagation characteristic from the first light emitting diode to the second light emitting diode and a light propagation characteristic from the second light emitting diode to the first light emitting diode. A physical structure is incorporated to increase the
The optical tactile proximity sensor according to claim 4. An optical tactile proximity sensor that detects the approach of an object,
A plurality of light emitting diodes spaced apart from each other;
A light emitting diode set to the light emitting mode and the light receiving mode is selected from a plurality of light emitting diodes, and the light emitting diode set to the light receiving mode receives light emitted from the light emitting diode set to the light emitting mode and reflected by the object. Switching means for setting the mode of the light-emitting diode,
Measuring means for measuring the amount of light received by the light emitting diode set in the light receiving mode;
Detecting means for detecting the approach of the object based on the measured amount of received light,
An optical tactile proximity sensor. When detecting the approach of an object, the switching means sequentially selects a light emitting diode to be set to a light emitting mode and a light emitting diode to be set to a light receiving mode from a plurality of light emitting diodes, and each time the measuring means Measure the amount of light received by the light emitting diode set in the light reception mode, the detection means detects the approach position of the object based on the amount of light received,
The optical tactile proximity sensor according to claim 10.

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