JP2008096179A - Optical position detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical position detection device capable of enlarging a display domain. <P>SOLUTION: A touch panel A1 includes a liquid crystal display 1 for displaying an image, a plurality of light emitting elements 2a-2t and a plurality of light receiving elements 3a-3t arrayed in parallel mutually across the liquid crystal display 1, and a control means 4 for driving and controlling the plurality of light emitting elements 2a-2t and the plurality of light receiving elements 3a-3t. The control means 4 has a constitution wherein two mutually adjacent light emitting elements 2f, 2g among the plurality of light emitting elements 2a-2t are allowed to emit light simultaneously, and when each light from the two light emitting elements 2f, 2g is not received by one light receiving element 3q facing to the light emitting elements 2f, 2g among the plurality of light receiving elements 3a-3t, it is determined that a finger Fg exists between the two light emitting elements 2f, 2g and the light receiving element 3q. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical position detection device such as a touch panel.

  FIG. 5 shows an example of a conventional touch panel (see, for example, Patent Document 1). The touch panel X shown in the figure includes a liquid crystal display 91, a plurality of light emitting elements 92a to 92t, a plurality of light receiving elements 93a to 93t, and a control means 94. The plurality of light emitting elements 92a to 92j and the plurality of light receiving elements 93k to 93t are arranged in parallel along the direction y with the liquid crystal display 91 interposed therebetween. The plurality of light emitting elements 92k to 92t and the plurality of light receiving elements 93a to 93j are arranged in parallel along the direction x with the liquid crystal display 91 interposed therebetween. The control means 94 includes a light emitting element driver 94a, a light receiving element driver 94b, and a CPU 94c. The CPU 94c sequentially causes the plurality of light emitting elements 92a to 92t to emit light via the light emitting element driver 94a. Further, the CPU 94c detects the presence / absence of light reception of the light receiving elements 93a to 93t located in front of the light emitting elements 92a to 92j through the light receiving element driver 94b. For example, when a part desired by the user is touched with the finger Fg in the image displayed on the liquid crystal display 91, the light emitted from the light emitting element 92g is blocked by the finger Fg. At this time, since the light receiving element 93q does not receive the light from the light emitting element 92g, the light receiving detection signal from the light receiving element 93q is not transmitted to the light receiving element driver 94b and the CPU 94c. Thereby, the CPU 94c recognizes that a shielding object such as the finger Fg is between the light emitting element 92g and the light receiving element 93q. By performing this shielding object recognition processing on the plurality of light emitting elements 92a to 92t and the plurality of light receiving elements 93a to 93t according to a predetermined frequency, the direction x of the shielding object such as the finger Fg existing on the liquid crystal display 91 and A position in the direction y can be detected.

  However, the light emitting luminance of the light emitting elements 92a to 92t is limited. The distance between the light emitting elements 92a to 92t and the light receiving elements 93a to 93t facing each other is such that light from the light emitting elements 92a to 92t can be reliably received by the light receiving elements 93a to 93t. Must be a distance. Accordingly, the size of the liquid crystal display 91 in the direction x and the direction y is limited by the light emission luminance of the plurality of light emitting elements 92a to 92t, and the increase in size of the liquid crystal display 91 is hindered.

JP 2000-242433 A

  The present invention has been conceived under the circumstances described above, and an object of the present invention is to provide an optical position detection device capable of enlarging the display area.

  An optical position detection apparatus provided by the present invention includes a display area for displaying an image, a plurality of light emitting elements and a plurality of light receiving elements arranged in parallel with each other across the display area, and the plurality of light emitting elements. And an optical position detection device comprising: a control means for driving and controlling the plurality of light receiving elements; and the control means is configured to control two or more light emitting elements adjacent to each other among the plurality of light emitting elements. When the light from the two or more light emitting elements is not received by one light receiving element that emits light at the same time and faces the two or more light emitting elements among the plurality of light receiving elements, the two or more light emitting elements and the one light emitting element It is characterized in that it is determined that a shielding object exists between the light receiving element and the light receiving element.

  According to such a configuration, the one light receiving element receives light from the two or more light emitting elements. For this reason, it is possible to make the distance between the plurality of light emitting elements and the plurality of light receiving elements facing each other, for example, twice or more. Therefore, the display area can be increased in size.

  In a preferred embodiment of the present invention, the one light receiving element facing the two or more light emitting elements that emit light simultaneously has a position in a direction in which the plurality of light emitting elements and the plurality of light receiving elements are arranged, The positions of the two or more light emitting elements that emit light simultaneously are averaged. According to such a configuration, light emitted from the two or more light emitting elements can be received most efficiently by the one light receiving element. This is advantageous for enlarging the display area.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  FIG. 1 shows an example of an optical position detection apparatus according to the present invention. The touch panel A1 of the present embodiment includes a liquid crystal display 1, a plurality of light emitting elements 2a to 2t, a plurality of light receiving elements 3a to 3t, and a control unit 4. The touch panel A1 is configured to be able to detect the position indicated by the user with the finger Fg with respect to the liquid crystal display 1 on which an image or the like is displayed in the direction x and the direction y.

  The liquid crystal display 1 is an image display device capable of displaying a color image, for example, and constitutes a display area referred to in the present invention. The liquid crystal display 1 has a rectangular shape having four sides extending along the direction x and the direction y.

  The plurality of light emitting elements 2a to 2t are light emitting diodes capable of emitting infrared rays, for example. The plurality of light emitting elements 2a to 2j are arranged at an equal pitch along the direction y on the left side of the liquid crystal display 1 in the figure. The plurality of light emitting elements 2k to 2t are arranged at an equal pitch along the direction x on the upper side of the liquid crystal display 1 in the figure.

  The plurality of light receiving elements 3a to 3t are, for example, photodiodes or phototransistors, and can receive infrared rays having wavelengths emitted from the plurality of light emitting elements 2a to 2t. The plurality of light receiving elements 3a to 3j are arranged along the direction x in parallel with the plurality of light emitting elements 2k to 2t with the liquid crystal display 1 interposed therebetween. The plurality of light receiving elements 3a to 3j have the same arrangement pitch as the arrangement pitch of the plurality of light emitting elements 2k to 2t. The plurality of light emitting elements 2k to 2t and the plurality of light receiving elements 3a to 3j have the same position in the direction x between those facing each other. The plurality of light receiving elements 3k to 3t are arranged along the direction y in parallel with the plurality of light emitting elements 2a to 2j with the liquid crystal display 1 interposed therebetween. The plurality of light receiving elements 3k to 3t have the same arrangement pitch as the arrangement pitch of the plurality of light emitting elements 2a to 2j. The plurality of light emitting elements 2a to 2j and the plurality of light receiving elements 3k to 3t have the same position in the direction y between those facing each other.

  The control unit 4 includes a light emitting element driver 41, a light receiving element driver 42, and a CPU 43. The light emitting element driver 41 is configured to emit any one of the plurality of light emitting elements 2 a to 2 t based on a command from the CPU 43. The light receiving element driver 42 is configured to be able to transmit to the CPU 43 that any one of the plurality of light receiving elements 3a to 3t has received light. The CPU 43 is for performing position detection processing using the plurality of light emitting elements 2 a to 2 t and the plurality of light emitting elements 2 a to 2 t via the light emitting element driver 41 and the light receiving element driver 42.

  The position detection process by the touch panel A1 is performed as follows. The CPU 43 sends a command to the light emitting element driver 41 to sequentially emit the plurality of light emitting elements 2a to 2t according to a predetermined frequency. In this light emitting operation, two adjacent light emitting elements 2a to 2t are caused to emit light simultaneously. That is, the two light emitting elements 2a and 2b, the two light emitting elements 2b and 2c, the two light emitting elements 2c, 2d,... The CPU 43 performs light reception detection operation of the plurality of light receiving elements 3 a to 3 t via the light receiving element driver 42 in synchronization with the light emitting operation via the light emitting element driver 41.

  FIG. 2 shows a part of a timing chart of these light emission operations and light reception detection operations. As clearly shown in the figure, for example, the light emission of the two light emitting elements 2f and 2g and the light reception detection by the light receiving element 3q are performed at the same timing. As shown in FIG. 1, the light receiving element 3q faces the light emitting element 2g out of the two light emitting elements 2f and 2g. At this time, when the user's finger Fg is placed between the two light emitting elements 2f and 2g and the light receiving element 3q, the light receiving element 3q does not receive light from the two light emitting elements 2f and 2g. When the light receiving detection signal of the light receiving element 3q is not transmitted from the light receiving element driver 42 even though the two light emitting elements 2f and 2g emit light, the CPU 43 causes the two light emitting elements 2f and 2g and the light receiving element 3q to be transmitted. It is recognized that the finger Fg exists between That is, the position of the finger Fg in the direction y can be detected. By performing drive control of the plurality of light emitting elements 2a to 2t and the plurality of light receiving elements 3a to 3t according to the timing chart shown in FIG. 2, position detection processing in the direction x and the direction y of the shielding object such as the finger Fg is performed. It can be carried out.

  Next, the operation of the touch panel A1 will be described.

  According to the present embodiment, when there is no shielding object such as the finger Fg, for example, light from the two light emitting elements 2f and 2g reaches one light receiving element 3q used for position detection processing. The distance at which the light from the two light emitting elements 2f and 2g can be received by the light receiving element 3q is about twice the distance that can be received by the light receiving element 3q when only one of the light emitting elements 2f and 2g emits light. is there. Therefore, the distance between the plurality of light emitting elements 2a to 2j and the plurality of light receiving elements 3k to 3t, and the distance between the plurality of light emitting elements 2k to 2t and the plurality of light receiving elements 3a to 3j, for example, are shown in FIG. The distance on the touch panel X shown in FIG. Accordingly, it is possible to increase the size of the liquid crystal display 1 in the touch panel A1.

  3 and 4 show another embodiment of the present invention. In these drawings, the same or similar elements as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment.

  FIG. 3 shows a second embodiment of the optical position detection apparatus according to the present invention. The touch panel A2 of the present embodiment is different from the above-described embodiment in that three of the light emitting elements 2a to 2t are caused to emit light simultaneously in the position detection process. In the present embodiment, for example, when the three light emitting elements 2e, 2f, and 2g are caused to emit light, it is determined whether or not there is a shielding object such as the finger Fg by determining whether or not the light receiving element 3p is receiving light. To do. The light receiving element 3p has the same position in the direction y as the light emitting element 2f located at the center of the three light emitting elements 2e, 2f, 2g. The relationship between the light emitting elements 2a to 2t and the light receiving elements 3a to 3t other than the three light emitting elements 2e, 2f and 2g and the light receiving element 3p is the same.

  According to such an embodiment, the enlargement of the liquid crystal display 1 can be further promoted. The light receiving element 3p is arranged at a position where the light from the three light emitting elements 2e, 2f, 2g can be received most efficiently. Therefore, it is possible to increase the sensitivity for detecting the presence or absence of the shielding object, which is advantageous for increasing the size of the liquid crystal display 1.

  FIG. 4 shows a third embodiment of the optical position detection apparatus according to the present invention. The touch panel A3 of the present embodiment is the same as the first embodiment described above in that two of the plurality of light emitting elements 2a to 2t simultaneously emit light, but the plurality of light emitting elements 2a to 2t and the plurality of light receiving elements. The relative positional relationship with the elements 3a to 3r is different from that of the first embodiment described above. In the present embodiment, for example, a light receiving element 3o that should receive light from two light emitting elements 2f and 2g is disposed between the light emitting elements 2f and 2g in the direction y. That is, the light receiving element 3o is a position obtained by averaging the positions in the direction y of the light emitting elements 2f and 2g. Similarly, the plurality of light emitting elements 2a to 2j and the plurality of light receiving elements 3j to 3r, or the plurality of light emitting elements 2k to 2t and the plurality of light receiving elements 3a to 3i are arranged so as to be shifted from each other by a half pitch.

  Also according to such an embodiment, the size of the liquid crystal display 1 can be increased. Further, the light from the plurality of light emitting elements 3a to 3t can be efficiently received by the plurality of light receiving elements 3a to 3r.

  The optical position detection device according to the present invention is not limited to the embodiment described above. The specific configuration of each part of the optical position detection device according to the present invention can be varied in design in various ways.

1 is an overall schematic diagram showing a first embodiment of an optical position detection device according to the present invention. It is a timing chart which shows the position detection process by 1st Embodiment of the optical position detection apparatus which concerns on this invention. It is the whole schematic figure which shows 2nd Embodiment of the optical position detection apparatus which concerns on this invention. It is the whole schematic figure which shows 3rd Embodiment of the optical position detection apparatus which concerns on this invention. It is the whole schematic diagram which shows the conventional optical position detection apparatus.

Explanation of symbols

A1, A2, A3 Touch panel (optical position detector)
1 Liquid crystal display (display area)
2a to 2t Light emitting elements 3a to 3t Light receiving element 4 Control means 41 Light emitting element driver 42 Light receiving element driver 43 CPU

Claims (2)

A display area for displaying images,
A plurality of light emitting elements and a plurality of light receiving elements arranged in parallel with each other across the display region;
Control means for driving and controlling the plurality of light emitting elements and the plurality of light receiving elements;
An optical position detection device comprising:
The control unit causes two or more light emitting elements adjacent to each other among the plurality of light emitting elements to emit light simultaneously, and the two or more light receiving elements face each other with the two or more light emitting elements among the plurality of light receiving elements. An optical position detection device configured to determine that a shielding object exists between the two or more light emitting elements and the one light receiving element when light from the light emitting elements is not received. .   The one or more light emitting elements facing the two or more light emitting elements that emit light simultaneously are the two or more light emitting elements that emit light at the same time in the direction in which the plurality of light emitting elements and the plurality of light receiving elements are arranged. The optical position detection device according to claim 1, wherein the positions are averaged positions.

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