JP2005316517A - Optical touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical touch panel having reduced manufacturing cost with the number of light receiving elements greatly reduced and simplified construction for eliminating the need for highly accurate optical adjustment. <P>SOLUTION: The optical touch panel comprises a plurality of projecting elements X1, X2, Xn; Y1, Y2, Yn arranged along two adjacent sides 3a, 3b of a rectangular display screen 2 for emitting lights parallel to the display screen 2 and perpendicular to the arrangement sides, photo conductive members 4A, 4B provided along the remaining two adjacent sides 3c, 3d of the display screen 2, respectively, and containing fluorescent materials which emit lights with the lights from the opposed projecting elements X1, X2, Xn; Y1, Y1, Yn, and light receiving elements 5A, 5B provided one ends of the photo conductive members 4A, 4B, respectively, for receiving the lights emitted from the fluorescent materials. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical touch panel, and more particularly, for information input provided in a display unit of an FA (factory automation) device, a vending machine, a vending machine, an information device, a home appliance, a medical operation device, or the like. The present invention relates to an optical touch panel.

  As the touch panel, a resistance film type, an optical type, and the like are widely known. The resistive touch panel is configured such that upper and lower transparent electrodes are arranged to face each other with a slight space, and the input position is detected by contact of the transparent electrodes. In addition, as shown in FIG. 8, the general configuration of the optical touch panel includes a plurality of light projecting elements 51 arranged on two adjacent sides of the display screen 50, and light from the light projecting elements 51 on the remaining two sides. Is arranged. Then, the light projecting elements 51 are sequentially pulsed, and the input operation position on the display screen is detected in accordance with light shielding by a finger or the like that performs the input operation on the display screen.

  However, the resistive film type touch panel requires a transparent plate on which a transparent electrode is deposited. Since this transparent plate has a transmittance of about 70% at the maximum, there is a problem that sufficient luminance cannot be obtained especially in an increasing number of display panels using reflective liquid crystal for power saving. is there.

On the other hand, the optical touch panel requires a number of light receiving elements and processing circuits corresponding to the light projecting elements, and there are problems such as an increase in cost, power consumption, and an increase in installation space.
Therefore, an optical touch panel has been proposed to solve the problems caused by the need for a large number of the light receiving elements as well as the optical touch panel to solve the problems of the resistive touch panel. Kaihei 6-309100). In the optical touch panel disclosed in Japanese Patent Laid-Open No. 6-309100, a plurality of light projecting elements are arranged on two adjacent sides of a display screen, light guide members are provided on the remaining two sides, and light from the light projecting elements is provided. Is guided to a light receiving element provided at a corner portion of the display screen that has passed through the light guide member, and is converted into an electrical signal corresponding to the received light. Therefore, it is only necessary to provide the light receiving elements at the corners of the display screen, and the number of light receiving elements is greatly reduced, and the manufacturing cost and power consumption can be greatly reduced.

JP-A-6-309100

However, the optical touch panel described in Patent Document 1 has the following problems.
(1) That is, the light guide member of Patent Document 1 includes a reflecting plate for reflecting light from the light projecting element and efficiently guiding the light to the light receiving element. Therefore, it is necessary to adjust the angle of the reflecting plate. . This is because if the reflector is not well arranged, light leakage from the light guide member occurs, resulting in light reception lacking in accuracy and erroneous detection. However, it is difficult to actually arrange with high accuracy. In particular, in the case of a large display panel of 14 inches or more such as a control input device, the light path from the reflecting surface of the reflecting plate to the light receiving element is long. For this reason, even if there is a slight error in the angle adjustment of the reflecting surface, the light receiving element cannot be accurately focused and erroneous detection occurs.

  (2) Further, in the case of a large display screen of 14 inches or more such as a control input device, the size of the reflector is increased, and a light receiving element having a large light receiving surface is required accordingly, and the device is enlarged. .

  The present invention has been devised in view of the above circumstances, and its purpose is to significantly reduce the number of light receiving elements, to reduce the manufacturing cost, and to realize the simplification of the configuration. An optical touch panel that does not require high-precision optical adjustment can be provided.

  In order to achieve the above object, the invention according to claim 1 of the present invention is arranged in plural along two adjacent sides of a rectangular display screen, and is parallel to the display screen and perpendicular to the arranged sides. A light emitting element that emits light, a light guide that is provided along the remaining two adjacent sides of the display screen, and that contains a fluorescent material that emits light by the light from the facing light projecting element, and one end of the light guide And a light receiving element for receiving light emitted from the fluorescent material.

  With the above configuration, the number of light receiving elements and their processing circuits can be reduced to two as compared with the conventional example. Along with this, an enormous amount of processing circuit becomes unnecessary. As a result, the manufacturing cost can be reduced and the configuration can be simplified. In addition, since the fluorescent material is caused to emit light by the light of the light projecting element and the emitted light is guided to the light receiving element, high-precision optical adjustment as in the conventional example is not required.

  The invention described in claim 2 is the optical touch panel described in claim 1, characterized in that a reflecting plate is provided at the other end of each light guide.

  With the above-described configuration, light that has been emitted from the fluorescent material in a random direction can be reflected and guided to the light receiving element side while the light traveling on the end side of the light guide opposite to the light receiving element side is reflected.

  The invention according to claim 3 is the optical touch panel according to claim 1 or 2, wherein a transparent or translucent pressing plate arranged near the upper part of the display screen and the pressing of the pressing plate are detected. It is characterized by comprising detecting means and driving means for applying vibration to the pressing plate when the pressing of the pressing plate is detected by the detecting means.

  With the above configuration, vibration and click feeling can be obtained, so that the operational feeling and operational reliability as a switch are improved.

  According to a fourth aspect of the present invention, there is provided the optical touch panel according to the third aspect, further comprising lighting driving means for sequentially pulsing the light projecting elements when the pressing means detects the pressing plate. Features.

  With the above configuration, since the light projecting element is lit only when the pressing plate is operated, power saving can be achieved, and deterioration due to the use of the light projecting element can be reduced as much as possible.

  According to the present invention, since only two light receiving elements and a processing circuit need be provided, the number of light receiving elements and processing circuits can be greatly reduced as compared with the conventional example. As a result, the manufacturing cost can be reduced and the configuration can be simplified. Further, by using a light guide containing a fluorescent material, there is an effect that high-precision optical adjustment as in the conventional example is not required.

  Hereinafter, an optical touch panel according to the present invention will be described in detail based on embodiments. Note that the present invention is not limited to the following embodiments.

(Embodiment 1)
FIG. 1 is a plan view showing the overall configuration of the optical touch panel according to Embodiment 1. FIG. In the following example, a case where an optical touch panel is applied to a display screen of 14 inches or more will be described. Of course, it can be applied to a display screen of 14 inches or less.

  The optical touch panel 1 is a collective term for light projecting elements X1, X2,..., Xn (light projecting elements X1, X2,..., Xn) arranged along two adjacent sides 3a, 3b of a rectangular display screen 2. Y1, Y2,..., Yn (light emitting elements Y1, Y2,..., Yn are collectively indicated by reference symbol Y) and the remaining two adjacent sides of the display screen 2 Long light guides 4A and 4B provided along 3c and 3d, respectively, and light receiving elements 5A and 5B provided at end portions of the light guides 4A and 4B are provided. A reflecting plate 6 (see FIG. 2) is disposed at the end opposite to the end where the light receiving elements 5A and 5B are disposed, of both ends of the light guides 4A and 4B. . As will be described later, the reflecting plate 6 reflects light that has traveled to the end side opposite to the light receiving element side of the light guides 4A and 4B out of light emitted in a random direction from the fluorescent material. It fulfills the function of leading to the light receiving element side.

  As the light projecting elements X and Y, for example, LEDs (light emitting diodes) that emit ultraviolet light or visible light, LDs (laser diodes), or the like are used. The light projecting element X is configured to emit light parallel to the display screen 2 and perpendicular to the side 3a, and the light projecting element Y is configured to emit light parallel to the display screen 2 and perpendicular to the side 3b. Has been. For this reason, when LEDs (LEDs other than LEDs that emit spot light) are used as the light projecting elements X and Y, it is preferable to dispose a condensing lens made of, for example, an aspheric lens on the emission surface side of each LED. In this way, the diffused light from the LED is condensed by the condensing lens and emitted as beam light. Therefore, if there are fingers or touch pens for input operation on the display screen, The light is shielded and accurate detection is possible. If the condensing lens is not provided, the light from the LED is diffused light, so the light from the LED is not completely blocked by the finger or the touch pen and is incident on the light guides 4A and 4B. Occurs.

  In addition, when using LED which emits spot light, it is not necessary to arrange | position said condensing lens.

  In addition, when LD is used as the light projecting elements X and Y, light from the LD does not diffuse and a straight line is good. Therefore, even if a condenser lens is not provided, the light is completely blocked by a finger or a touch pen on the display screen. And no false detection will occur.

  Here, it should be noted that the light guides 4A and 4B contain a fluorescent material. The fluorescent material absorbs light (excitation light) from the light projecting elements X and Y, and has a wavelength longer than that of the excitation light when returning from the excited state (excited state) to the original state (ground state). (Fluorescence) has a characteristic of releasing energy, and in the present invention, by utilizing such a characteristic, the fluorescent material is caused to emit light by the light from the light projecting elements X and Y, and the light from the fluorescent material is emitted. Is guided to the light receiving element. Hereinafter, the operation principle will be described in detail with reference to FIG.

  When the light L1 from the light projecting element X enters the light guide 4A and is irradiated onto the fluorescent material 7 in the light guide 4A, the light is emitted from the fluorescent material 7 in a random direction. At this time, the refractive index of air is about 1, and the refractive index of the resin of the light guide 4A is in the range of about 1.2 to 2. Therefore, the light from the fluorescent material 7 is transmitted from the inside of the light guide 4A to the outside. Is not reflected on the light path, but is totally reflected in the light guide 4A and directly follows the light path L2 guided to the end portion on the light receiving element 5A side, or is reflected on the reflecting plate 6 and then reflected on the light receiving element 5A side. The optical path L3 guided to the end is traced. The operation principle related to the light projecting element Y and the light guide 4B is the same as the operation principle related to the light projecting element X and the light guide 4A.

  Therefore, in the present invention based on such an operation principle, high-level optical adjustment as in the conventional example is not required for the light projecting elements X and Y, the light guides 4A and 4B, and the light receiving elements 5A and 5B.

  Further, as apparent from the above operating principle, in the present invention, it is sufficient that the fluorescent material contained in the light guides 4A and 4B emits light (fluorescence) using the light from the light projecting elements X and Y as excitation light. Therefore, the emission color of the light projecting elements X and Y and the emission color of the fluorescent material are not particularly limited. However, the emission color of the fluorescent material is closer to the infrared region because the S / N ratio is better from the relationship of the light receiving sensitivity of the light receiving element, which is desirable from the viewpoint of detection sensitivity.

  Further, when LEDs emitting blue light or ultraviolet light are used as the light projecting elements X and Y, when red is selected as an example of the light emitted by excitation of the fluorescent material, a red filter is provided in front of the light receiving elements 5A and 5B. It is desirable to arrange. In this way, only a pure red component can be guided to the light receiving elements 5A and 5B, and detection with a good S / N ratio can be performed. In addition, since disturbance light from a fluorescent lamp or the like can also be shielded by the red filter, it is possible to perform detection with a good S / N ratio from this viewpoint.

  The light guides 4A and 4B are formed by mixing a fluorescent material and a transparent resin material into a predetermined shape. As specific examples of the materials of the light guides 4A and 4B, acrylite (product number 995 or product number 994) manufactured by Mitsubishi Rayon, phosphor plate manufactured by Kawasaki Sanko Kasei (sample No. 95004, sample No. 95005, sample no. .90612) and the like. The light guides 4A and 4B may have a circular cross section perpendicular to the axis, and may be an ellipse, a rectangle, a triangle, a polygon, or other shapes.

  The light receiving elements 5A and 5B are, for example, photodiodes or phototransistors, and have a photoelectric conversion function of converting into electric signals according to the amount of received light.

  The light projecting elements X and Y are sequentially pulsed by a light projecting circuit which will be described later, and the light receiving elements 5A and 5B perform light receiving processing in synchronization with the pulse lighting of the light projecting elements X and Y. As the driving timing, the X direction light projecting elements X1, X2,..., Xn are pulsed in this order, and then the Y direction light projecting elements Y1, Y2,. To do. Of course, the order of pulse lighting may be the order of the Y direction light projecting elements Y1, Y2,..., Yn, and then the X direction light projecting elements X1, X2,. Alternatively, the X-direction light projecting element X and the Y-direction light projecting element Y may be pulsed simultaneously.

  Further, pulse lighting of the light projecting elements X and Y may be performed at all times, and the detection means detects that an input operation has been performed on the display screen 2 as in the third embodiment to be described later. It may be done only occasionally. If it is performed only when it is detected that an input operation has been performed on the display screen, the light emitting element will not be turned on unnecessarily, the power consumption can be reduced, and the use of the light projecting element The progress of deterioration due to can be reduced as much as possible.

  FIG. 3 is an example of a block diagram showing an electrical configuration of the optical touch panel, and FIG. 4 is an example of a signal waveform diagram when position information of the optical touch panel is detected. When the activation signal from the CPU 9 is given to the timing generation circuit 10, the timing generation circuit 10 generates a timing signal shown in FIG. 4A, and the light projecting circuit 11A for the light projecting element X and the light projecting element Y are generated. To the projector circuit 11B. The activation signal from the CPU 9 is output every period when scanning of at least all the light projecting elements X1, X2,..., Xn; Y1, Y2,.

  Next, the light projecting circuit 11A sequentially turns on the light projecting elements X1, X2,..., Xn as shown in FIG. Then, when the light from the light projecting elements X1, X2,..., Xn is incident on the light guide 4A and irradiated onto the fluorescent material in the light guide 4A, the fluorescence is based on the operation principle of FIG. The material emits light, and the emitted light is guided to the light receiving element 5A. Then, the X-direction light receiving circuit 12A inputs a light receiving signal from the light receiving element 5A in synchronization with the drive timing of the light projecting circuit 11A. Here, for example, in a state where the optical touch panel 1 is not operated, as shown in FIG. 4 (3), a continuous light reception pulse exists in the light reception signal. However, in the state in which the optical touch panel 1 is operated, the light from the light projecting element X related to the pushing position is blocked by a finger or the like, so the fluorescent material contained in the light guide 4A does not emit light, Therefore, as shown in FIG. 4 (4), the received light signal does not include a part of the continuous received light pulse (see the period from time T3 to T4 in FIG. 4 (4)).

  Next, the push-in position calculation circuit 13 compares the timing signal and the light reception signal, and obtains the position signal of the X direction component corresponding to the period without the light reception signal (period T3 to T4 in the example of FIG. 4 (4)). The signal is output to the position signal output circuit 14.

  The position detection in the Y direction is performed by the same process as the position detection in the X direction. Then, the position signal of the Y direction component is output from the push position calculation circuit 13 to the position signal output circuit 14. In FIG. 3, reference numeral 12B denotes a light receiving circuit for Y direction.

  Next, the operation of the optical touch panel 1 having the above configuration will be described with a specific example. Assume that the pushing position is the position of the point P (2, 3) (see FIG. 1) in the x-Y coordinate system. At this time, since the light from the light projecting element X2 is shielded by a finger or the like, the light is not emitted from the fluorescent material in the light guide 4A. Therefore, the light reception signal has no light reception pulse only during the light emission period of the light projecting element X2. As a result, the X-direction position of the pushing position is recognized as “2”.

  Similarly, since the light from the light projecting element Y3 is shielded by a finger or the like, the light is not emitted from the fluorescent material in the light guide 4B. Therefore, the light reception signal has no light reception pulse only during the light emission period of the light projecting element Y3. As a result, the Y-direction position of the push-in position is recognized as “3”. In this way, it is recognized that the pushing position is (2, 3).

(Embodiment 2)
FIG. 5 is a cross-sectional view of the optical touch panel according to the second embodiment. 5A shows a normal state in which an input operation is not performed with a finger or the like, and FIG. 5B shows a state in which an input operation is performed with a finger or the like.

  The second embodiment is similar to the first embodiment, and corresponding portions are denoted by the same reference numerals, and detailed description thereof is omitted. In the second embodiment, the optical touch panel of the first embodiment is combined with a display capable of giving an operational feeling due to vibration. A display that can give a feeling of operation by vibration is detected when the applicant has pushed the entire screen, as already proposed in Japanese Patent Laid-Open Nos. 9-161602 and 10-293644. Then, the entire screen is vibrated to give the operator a feel such as vibration and to let the operator sense that the operation has been performed.

  Hereinafter, a specific configuration will be described with reference to the drawings.

  A transparent or translucent pressing plate 21 is disposed above the display screen 2 of the display device 20. Between the pressing plate 21 and the display drawing 2, one or more driving units 22 that mechanically drive the pressing plate 21 and give a touch response such as vibration to the operator of the pressing plate 21 are provided. The entire pressing plate 21 is supported by the driving unit 22 so as to be able to be pushed in. In FIG. 5, the drive unit 22 is schematically illustrated, and the specific configurations described in JP-A-9-161602 and JP-A-10-293644 are used.

  Between the display screen 2 and the pressing plate 21, a pressing detection switch 23 for detecting that the pressing plate 21 is pressed is provided. One indentation detection switch 23 may be provided, or a plurality of indentation detection switches 23 may be provided at a plurality of locations on the peripheral edge of the pressing plate 21. The indentation detection switch 23 may be a contact type such as a contact switch, a non-contact type such as a photoelectric switch, or a pressure-sensitive type such as a piezoelectric element. The push-in detection switch 23 may be provided on the display screen 2 as in this example, or may be provided in the drive unit 22. In short, it is only necessary to detect that the pressing plate 21 has been pushed.

  The number of the drive units 22 may be one, or may be provided at each of a plurality of locations on the peripheral portion of the pressing plate 21. The drive unit 22 uses, for example, (1) piezoelectric vibration, (2) a combination of an electromagnetic solenoid and a plunger, (3) a combination of an electromagnet and a permanent magnet, and (4) a vibration motor having an eccentric weight. be able to.

  Moreover, as an aspect which drives the press plate 21 mechanically by the drive part 22 and gives a tactile response to the operator of the press plate 21, for example, (1) The press plate 21 is vibrated, (2) The press plate 21 is used. Suddenly slide in the horizontal direction for a moment (one shot), (3) Suddenly slide the pressing plate 21 in the horizontal direction, and hold it while pressing (4) For a moment (one shot) (5) The pressing plate 21 is suddenly lowered and held while being pressed, (6) The pressing plate 21 is suddenly raised (one shot), (7) The pressing plate 21 is suddenly lowered And hold it while pushing, etc.

  A specific example of the tactile response given to the operator by the above is as follows. That is, in the case of (1), vibration is applied to the operator's finger or the like. In the above cases (2) to (5), both the stroke feeling that the switch portion of the pressing plate 21 is pushed by a certain stroke and the click feeling that the switch portion is suddenly operated are applied to the operator's finger and the like. Given. In the case of (6) and (7), a click feeling that the pressing plate 21 is suddenly operated is given to the operator's finger or the like by the stimulus that the pressing plate 21 pushes up.

  In FIG. 5, reference numeral 25 denotes a disturbance light prevention cover, and this disturbance light prevention cover 25 covers the entire length of the light guide tube. The disturbance light prevention cover 25 is used not only in the second embodiment but also in the first embodiment and the third embodiment to be described later.

  As described above, in the second embodiment, in addition to the effects of the first embodiment in which the manufacturing cost is reduced due to a significant reduction in the number of light receiving elements and high-precision optical adjustment is not required, vibration and clicks are performed. Since a feeling is obtained, the operational feeling as a switch and the operational reliability are improved.

  In the above example, the structure in which the entire pressing plate 21 is supported so as to be pushed by the drive unit 22 has been described. However, as described in JP-A-9-161602 and JP-A-10-293644, the pressing plate 21 may be supported by the support plate, and the support plate may be supported by the drive unit 22, and the indentation detection switch 23 may be interposed between the support plate and the pressing plate 21.

  Further, in the above example, when the pressing plate 21 is pressed with a relatively large stroke, the pressing detection switch 23 is configured to detect that, but as shown in FIG. When it is pushed in with a very small stroke, for example, a stroke about the thickness of the pressing plate 21, the push-in detection switch 23 (even if it is an optical detection switch comprising the light projecting element 23a and the light receiving element 23b shown in FIG. May be configured to detect this. 6A shows a normal state in which an input operation is not performed with a finger or the like, and FIG. 6B shows a state in which an input operation is performed with a finger or the like. In FIG. 6, the drive unit 22 is omitted for ease of illustration.

(Embodiment 3)
FIG. 7 is a block diagram showing an electrical configuration of the third embodiment. The third embodiment is similar to the second embodiment, and corresponding portions are denoted by the same reference numerals, and detailed description thereof is omitted. The third embodiment is characterized in that when the pressing of the pressing plate 21 is detected, the light projecting element is pulse-lit. In other words, the pressing detection signal from the pressing detection switch 23 is output to the drive unit 22 and also to the timing generation circuit 10. As a result, a predetermined vibration or the like is applied to the pressing plate 21 by the drive unit 22, and the X direction light projecting elements X1, X2,..., Xn are pulsed in this order, and then the Y direction light projecting element. Y1, Y2,..., Yn are pulsed in this order, and the same processing as described in the first embodiment is performed to detect the operation position.

  In this manner, in the third embodiment, the light projecting element is turned on only when the pressing plate 21 is operated, in addition to giving the operator a feeling of stroke or clicking. Therefore, since the light projecting element is turned on only when necessary, power saving can be achieved, and deterioration due to use of the light projecting element can be reduced as much as possible.

  Further, in the conventional optical touch panel, when insects such as flies stop on the display screen, the light from the light projecting element is blocked by the insects such as flies, which causes erroneous detection. When the pressing of the pressing plate 21 is detected, the light projecting element is lit in pulses, so that insects such as flies fly by the pressing of the pressing plate 21, and then the projecting element is pulsed. Therefore, false detection by insects such as flies can be prevented.

  In the above example, the optical path of the light emitted from the light projecting element to the light guide is configured to be positioned below the pressing plate 21 in the normal state, but is positioned above the pressing plate 21. In this case, the light projecting element is turned on when the pressing of the pressing plate 21 is detected, so that erroneous detection due to insects such as flies does not occur.

(Other matters)
(1) In the first to third embodiments, the light projecting element is driven by the drive pulse shown in FIG. 4 (for example, the frequency is several tens of KHz), but one pulse is modulated by a high frequency drive pulse having a frequency of several hundred KHz, for example. At the same time, high-frequency synchronous detection that detects a light reception signal in synchronization with the high-frequency driving pulse may be used. By using such high-frequency synchronous detection, detection with a good S / N ratio can be realized even when there is disturbance light.
(2) The display device used in the first to third embodiments may be a liquid crystal display, an EL (electroluminescence) display, a plasma display, a thin CRT, an LED array, or the like.

  The present invention can be suitably implemented not only for an information input touch panel such as a small information device using a small display panel but also for an information input touch panel such as a control device using a large display panel.

1 is a plan view showing an overall configuration of an optical touch panel according to Embodiment 1. FIG. It is a figure which shows the advancing state of the light in the light guide used for the optical touch panel which concerns on Embodiment 1. FIG. 3 is a block diagram showing an electrical configuration of the optical touch panel according to Embodiment 1. FIG. 6 is a signal waveform diagram when position information is detected by the optical touch panel according to Embodiment 1. FIG. It is sectional drawing of the optical touch panel which concerns on Embodiment 2, among which FIG. 5 (1) is sectional drawing which shows the normal state which is not input operation with a finger etc., FIG.5 (2) is input operation with a finger etc. It is sectional drawing which shows a state. It is sectional drawing of the modification of the optical touch panel which concerns on Embodiment 2, among which FIG. 6 (1) is sectional drawing which shows the normal state which is not input operation with a finger | toe etc., FIG. It is sectional drawing which shows the state which input-operated. FIG. 10 is a block diagram showing an electrical configuration of a third embodiment. It is a top view of the prior art example of an optical touch panel.

Explanation of symbols

1: Optical touch panel 2: Display screen 3a, 3b, 3c, 3d: Sides of display screen 4A, 4B: Light guide 5A, 5B: Light receiving element 6: Reflecting plate 7: Fluorescent material 20: Display device 21: Press plate 22: Drive unit 23: Pushing pressure detection switch X1, X2,..., Xn; Y1, Y2,.

Claims (4)

A plurality of light emitting elements that are arranged along two adjacent sides of a rectangular display screen and emit light in parallel to the display screen and perpendicular to the arranged sides;
A light guide containing a fluorescent material provided along each of the remaining two adjacent sides of the display screen and emitting light by the light from the facing light projecting elements;
A light receiving element that is provided at one end of the light guide and receives light emitted from the fluorescent material;
An optical touch panel characterized by comprising:   The optical touch panel according to claim 1, wherein a reflecting plate is provided at the other end of each light guide. A transparent or translucent pressing plate disposed in the upper vicinity of the display screen;
Detecting means for detecting depression of the pressing plate;
Drive means for applying vibration to the pressing plate when the pressing means detects the pressing plate;
The optical touch panel according to claim 1, comprising:   The optical touch panel according to claim 3, further comprising a lighting drive unit that sequentially turns on the light projecting element when the pressing unit detects the pressing of the pressing plate.