WO2000058820A1 - Optical scanning touch panel - Google Patents

Optical scanning touch panel Download PDF

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Publication number
WO2000058820A1
WO2000058820A1 PCT/JP1999/006528 JP9906528W WO0058820A1 WO 2000058820 A1 WO2000058820 A1 WO 2000058820A1 JP 9906528 W JP9906528 W JP 9906528W WO 0058820 A1 WO0058820 A1 WO 0058820A1
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WO
WIPO (PCT)
Prior art keywords
light
optical
scanning
touch panel
reflected
Prior art date
Application number
PCT/JP1999/006528
Other languages
French (fr)
Japanese (ja)
Inventor
Yasuhide Iwamoto
Satoshi Sano
Fumihiko Nakazawa
Nobuyasu Yamaguchi
Original Assignee
Fujitsu Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Limited filed Critical Fujitsu Limited
Publication of WO2000058820A1 publication Critical patent/WO2000058820A1/en

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Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
    • G06F3/0421—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means by interrupting or reflecting a light beam, e.g. optical touch-screen
    • G06F3/0423—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means by interrupting or reflecting a light beam, e.g. optical touch-screen using sweeping light beams, e.g. using rotating or vibrating mirror

Definitions

  • the present invention relates to an optical scanning touch panel that optically detects the position of an indicator on a display screen.
  • a human finger or a specific indicator is displayed on the display screen of a display device on which information is displayed by the computer system.
  • Devices that input new information or give various instructions to a computer system by giving instructions are used.
  • the angle of the finger or pen is determined from the mining, and the position coordinates are detected from the obtained angle by the principle of triangulation.
  • the number of parts is small, the detection accuracy can be maintained, and the position of a finger, an arbitrary pen, etc. can be detected.
  • An optical scanning type touch panel that performs position detection by using such scanning light generally includes a retroreflector provided outside the display screen, a light emitting element that emits light such as laser light, and a light emitting element that emits light.
  • Polygon scanning angle scan And a plurality of optical units including a light receiving element for receiving the light reflected by the retroreflector of the scanning light, and the light from the light emitting element is transmitted to each optical unit.
  • the light is scanned by the optical scanning unit.
  • the light reflected by the retroreflector of the scanning light is reflected again by the optical scanning unit, and the reflected light is received by the light receiving element.
  • the position of the pointing object can be detected.
  • an optical scanning type touch panel for example, when dust adheres to an optical scanning section such as a polygon mirror, the reflectance is deteriorated, the S / N ratio is reduced, and the accurate position of the indicator is determined. It cannot be detected. Also, not only the polygon mirror but also other optical members in the optical unit need to prevent external dust from adhering so that the characteristics are not deteriorated. However, in the conventional optical scanning type touch panel, no consideration is given to preventing this dust adhesion.
  • An object of the present invention is to provide an optical scanning type touch panel capable of detecting a position of an indicator accurately while suppressing deterioration of characteristics of members. Disclosure of the invention
  • An optical scanning type touch panel includes a light retroreflector provided outside a predetermined area, an optical scanning section for angularly scanning light in a plane substantially parallel to the predetermined area, and an optical scanning section. Anti-reflection of scanning light at the light retroreflector
  • the optical unit has a dust-proof structure having an optical opening surface in the scanning light area.
  • the optical unit has a dustproof structure, so that external dust does not enter the optical unit and adhere to the internal optical members. Therefore, characteristic deterioration of the optical member due to dust adhesion is suppressed, a stable operation for detecting the position of the pointer is performed, and an accurate position of the pointer can be detected.
  • the normal direction of the optical aperture surface is substantially equal to the direction of the scanning light at which the amount of reflected light is minimized.
  • the reflected light from the retroreflector with the minimum light quantity is incident on the optical aperture surface almost perpendicularly. Therefore, the reflected light with the minimum light amount can be efficiently received, and the detection accuracy can be improved.
  • a normal line of the optical aperture surface is inclined with respect to an optical axis of the scanning light.
  • the normal to the optical aperture is inclined with respect to the optical axis of the scanning light, and the scanning light emitted from the optical unit is specularly reflected at the optical aperture.
  • the inclination angle of a normal to the optical axis of the scanning light is less than half the viewing angle of the light receiving unit.
  • the inclination angle of the normal to the optical aperture surface with respect to the optical axis of the scanning light is larger than half the viewing angle of the light receiving section, and the viewing angle is limited for the light receiving section. Even if you go there, Does not interfere.
  • FIG. 1 is a schematic diagram showing a basic configuration of an optical scanning type touch panel of the present invention
  • FIG. 2 is a perspective view showing an optical system configuration and an optical path in an optical unit
  • FIG. 3 is a dustproof structure in the optical unit.
  • Sectional view Fig. 4 is a side view showing the dustproof structure in the optical unit
  • Fig. 5 is a sectional view showing the process of mounting the dustproof structure
  • Fig. 6 is a sectional view showing the state of attachment of the dustproof structure
  • Fig. 7 The figure is a schematic diagram showing the relationship between the scanning light and the incident angle with respect to the display screen
  • FIG. 8 is a graph showing the relationship between the incident angle and the transmittance in the visible light power filter
  • FIG. 9 is a diagram showing the relationship between the polygon mirror and the polygon mirror.
  • a diagram showing the positional relationship with the optical aperture surface
  • FIG. 10 is a diagram showing the relationship between the optical distances
  • FIG. 1i is a diagram showing the magnitude of the viewing angle
  • FIG. 12 is a dustproof structure in the optical unit.
  • FIG. 13 is a cross-sectional view showing a curved surface portion of the optical system.
  • FIG. 14 is a configuration diagram of another example of an optical unit with noise light countermeasures.
  • FIG. 15 is a schematic diagram showing an implementation state of an optical scanning type touch panel.
  • Fig. 16 is a schematic diagram showing the principle of triangulation for coordinate detection
  • Fig. 17 is a schematic diagram showing an indicator and a cut-off range
  • Timing chart shown-Fig. 19 is a schematic diagram showing the principle of measuring the diameter of the cross section of the pointer.
  • FIG. 1 is a schematic diagram showing a basic configuration of an optical scanning type touch panel of the present invention.
  • reference numeral 10 denotes a power supply of a personal computer or the like.
  • This is a rectangular display screen such as a CRT or flat display, “nel” (PD ⁇ , LCD, EL, etc.) in a slave device, a projection type video display device, etc.
  • a display screen of a PDP (brass display) It is configured as
  • one short side of this rectangular display screen 10 which is a range of a plane defined as a target area for touching with an indicator S such as a finger or a pen
  • the right side of Optical units 1a and 1b each having an optical system including a light-emitting element, a light-receiving element, a polygon mirror, various types of lenses, and the like are provided outside the two corners of each side.
  • Each of the optical units 1a and 1b is provided with a dustproof structure for preventing dust from entering from outside and preventing dust from adhering to the internal optical system. This dustproof structure will be described later in detail.
  • a retroreflective sheet 7 as a retroreflector is provided on three sides except the right side of the display screen 10, that is, outside the upper and lower sides and the left side. .
  • FIG. 2 is a perspective view showing an optical system configuration and an optical path in the optical unit 1a, lb. Both optical units 1a and 1b have the same optical system.
  • the optical units la and lb are a light emitting element 11 composed of a laser diode (LD) that emits infrared laser light and a collimator for converting laser light from the light emitting element 11 into parallel light. And a photo diode (PD) 13 for receiving light reflected from the retroreflective sheet 7 and a slit for limiting light incident on the light receiving element 13.
  • LD laser diode
  • PD photo diode
  • a slit plate 14 having 14 a, a polygon mirror 15 having, for example, a quadrangular prism shape for angularly scanning a laser beam from the light emitting element 11, and an aperture 16 a are used to collimate.
  • the light reflected from the retroreflective sheet 7 via the polygon mirror 15 is received by the light receiving element 13.
  • An optical unit main body 19 for mounting and fixing each optical member is provided.
  • Figures 3 and 4 are a cross-sectional view and a side view showing the dustproof structure of each optical unit 1a, 1b.
  • a dustproof cover 20 is provided in the optical units 1a and 1b so as to cover the above-described optical system.
  • the dust cover 20 is made of steel in which an inner surface covering the optical system is subjected to a non-reflection treatment. This anti-reflection treatment is applied to prevent the reflected light on the inner surface of the dust cover 20 from becoming noise light.
  • the emission area of the scanning light from the polygon mirror 15 is not provided with the dust cover 20, and the emission area is an optical aperture surface 21.
  • the optical aperture surface 21 may be made of any material that transmits light, and is made of, for example, transparent glass.
  • such a dustproof structure provides a completely hermetic structure, thereby preventing dust from entering from the outside. Therefore, this dustproof structure prevents dust from adhering to the optical members in the optical units 1a and lb. For example, reflection caused by the dust adherence of the polygon mirror 15 and the aperture mirror 16 The deterioration of the S / N ratio can be prevented without deterioration of the rate.
  • a guide groove 22 is formed in the optical unit main body 19 (FIGS. 5 (a) and 6), and a dust cover 20 is inserted into the guide groove 22. (Fig. 5 (b), Fig. 6).
  • the tip 20a of the dustproof cover 20 is provided with a hooking structure, and the dustproof cover 2 for the guide groove 22 is provided.
  • the process of attaching and detaching 0 is easy. No screws are required, and excellent maintenance such as optical axis adjustment is achieved.
  • the dustproof cover 20 and the optical unit main body 19 are guided by the positioning mechanism (the guide groove 22), and the dustproof cover 20 and the optical unit The main body 19 is fitted to the connector c to prevent dust from entering from outside.
  • this dustproof structure is completely built into the optical units 1a and 1b, and the dustproof structure does not increase the size of the optical units 1a and 1b.
  • the laser light emitted from the light emitting element 11 is converted into a collimation lens.
  • the light is collimated at 1 2, passes through the aperture 16 a of the aperture mirror 16, and is rotated by the polygon mirror 15 to form the optical aperture 2
  • the light is angularly scanned in a plane substantially parallel to the display screen 10 through 1 and projected on the retroreflective sheet 7. Then, the reflected light from the retroreflective sheet 7 is reflected by the polygon mirror 15 and the aperture mirror 16, and then condensed by the condenser lens 17, and is reflected by the slit plate 14. The light passes through the slit 14 a and enters the light receiving element 13. However, when the pointer S is present in the scanning light path, the reflected light is not incident on the light receiving element 13 because the projected light is blocked.
  • Each optical unit 1a, 1b includes a light emitting element driving circuit 2a, 2b for driving each light emitting element 11, and a light receiving signal detecting circuit 3 for converting the amount of light received by each light receiving element 13 into an electric signal. a, 3b, and a scan synchronization control circuit 4 for controlling the operation of each polygon mirror 15 to synchronize the start of optical scanning in each of the optical units la, lb. Also, reference symbols
  • Reference numeral 5 denotes an MPU that calculates the position and size of the pointer S and controls the operation of the entire device.
  • Reference numeral 6 denotes a table that displays the calculation results and the like of the MPU 5. Display device.
  • the MPU 5 sends a drive control signal to the light-emitting element drive circuits 2a and 2b, and the light-emitting element drive circuits 2a and 2b are driven according to the drive control signals, so that the light-emitting operation of each light-emitting element 11 is performed. Controlled.
  • the light receiving signal detection circuits 3 a and 3 b send the light receiving signals from the respective light receiving elements 13 to the MPU 5.
  • the MPU 5 calculates the position and size of the pointer S based on the light receiving signal from each light receiving element 13 and displays the calculation result on the display device 6.
  • the display device 6 can also serve as the display screen 10.
  • the light projected from the optical unit 1b is applied to the light receiving element 13 as shown in FIG. From the incident position, scanning is performed in the counterclockwise direction on FIG. 1, and the position (P s) where the light is reflected at the leading end of the retroreflective sheet 7 is a substantial scanning start position. Then, the light is reflected by the reflexive reflection sheet 7 up to the position (P 1) reaching one end of the pointer S, but is reflected up to the position (P 2) reaching the other end of the pointer S. The light is blocked by S and is reflected by the retroreflective sheet 7 until reaching the subsequent scanning end position (P e).
  • FIG. 7 is a schematic diagram showing a relationship between scanning light and an incident angle.
  • the optical aperture surface 21 is provided so that the direction of the scanning light at which the reflected light is minimized coincides or substantially coincides with the normal direction. Therefore, when the reflected light is minimized, the transmittance of the optical aperture surface 21 is maximized, and a decrease in the S / N ratio can be prevented.
  • FIG. 8 is a graph showing a relationship between an incident angle and a transmittance in a visible light cut filter. From FIG. 8, it can be seen that the transmittance becomes maximum near the incident angle of 0 degree. Therefore, when the reflected light is incident on the optical aperture surface 21 formed of the visible light cut filter at an incident angle of approximately 0 degree, the transmittance becomes maximum, and the position where the reflected light becomes minimum in this direction ( When the angle of incidence on the retroreflective sheet 7 is maximized), the S / N ratio is improved. In this case, the normal direction of the optical aperture surface 21 is set to a scanning angle of 60 degrees.
  • a transmittance higher than a predetermined value can be obtained in the range of an incident angle of ⁇ 45 degrees, so that the normal direction of the optical aperture surface 21 is set to 45 degrees or approximately 45 degrees.
  • a transmittance higher than a predetermined value within the entire scanning range (scan angle 0 to 90 degrees).
  • the normal direction of the optical aperture surface 21 is the direction of the optical axis of the scanning light from the polygon mirror 15.
  • a part of the scanning light from the polygon mirror 15 is specularly reflected on the optical aperture surface 21 and returns to the polygon mirror 15 with this setting.
  • Noise may occur.
  • the influence of the specular reflection component on the optical aperture surface 21 is eliminated.
  • the specular light from the optical aperture surface 21 is not received by the light receiving element 13 so that the normal line of the optical aperture surface 21 falls upward or downward with respect to the optical axis of the scanning light.
  • the optical aperture surface is such that the normal direction (dashed line B) of the optical aperture surface 21 is inclined upward by an angle ⁇ / 2 from the optical axis (solid line A) of the scanning light. 2 1 is set.
  • the specular reflection light of the scanning light from the polygon mirror 15 on the optical aperture surface 21 is directed away from the incident optical axis (solid line ⁇ ) by an angle ⁇ upward (solid line). Proceed to C), and the light is not received by the light receiving element 13 via the polygon mirror 15. Note that this angle ⁇ / 2 is called the opening plane inclination angle. Next, the setting of the opening plane inclination angle will be considered. In order to prevent specularly reflected light from the optical aperture surface 21 from being incident on the light receiving element 13, as shown in FIG.
  • the distance from the aperture mirror 16 to the light receiving lens 17 is D
  • the aperture Assuming that the distance from the polygon mirror 16 to the polygon mirror 15 is dL, the distance from the polygon mirror 15 to the optical aperture surface 21 is d L, and the radius of the light receiving lens 17 is B, Condition (1) should be satisfied.
  • the inclination angle of the opening face so as to satisfy the condition (1), it is possible to eliminate the above-described influence of the regular reflection.
  • ⁇ / 2 is close to 0, the transmittance is hardly attenuated in the optical aperture surface 21 with such a degree of inclination, and the transmittance is not a problem.
  • the dustproof cover 20 is made up of a resin-made visible light power filter having a characteristic of selectively transmitting light in a wavelength range of 700 nm or more. In such a case, in addition to the dust-proof function, a function of blocking disturbance light from fluorescent lamps, incandescent lamps, and the like can be performed.
  • An antireflection film is provided on the optical aperture surface 21. In this case, reflection at the optical aperture surface 21 is suppressed, and the influence of regular reflection can be eliminated.
  • Fig. 12 is a sectional view of the optical unit ia, lb.
  • the portion covering the polygon mirror 15 is a curved surface, and the shape of the curved surface is Is concentric with the circumcircle of the polygon mirror 15 (indicated by the dashed line in Fig. 12). Therefore, the airflow generated by the rotation of the polygon mirror 15 can be made smooth. As a result, the generation of airflow noise can be reduced, which is a measure against noise.
  • the diffused light from the aperture mirror i6 is reflected on the inner surface of the dust cover 20 to become noise light, and the noise light reaches the polygon mirror 15 to perform accurate detection processing. May not be. Therefore, use the following configuration to eliminate the influence of noise light.
  • FIG. 13 is a configuration diagram of an example of an optical unit in which such noise light countermeasures are taken.
  • a non-reflective sheet 23 is provided on the inner surface of the dust cover 20 so as to extend parallel to the optical path from the aperture mirror 16 to the polygon mirror 15. Therefore, the diffused light from the aperture mirror 16 serving as noise light is absorbed or scattered by the non-reflection sheet 23 and does not reach the polygon mirror 15. As a result, detection accuracy can be improved.
  • FIG. 14 is a configuration diagram of another example of an optical unit having such noise light countermeasures.
  • the dust cover 20 protrudes to the vicinity of the circumscribed circle of the polygon mirror 15, and the surface (the surface on the aperture mirror 16 side) and the rear surface (the surface of the polygon mirror 15) of the protrusion 2 Ob
  • a non-reflective sheet 23 is provided on the side surface). Therefore, the diffused light from the aperture mirror 16 serving as noise light is absorbed or scattered by the non-reflective sheet 23 on the surface side, and does not reach the polygon mirror 15. Also, even if there is noise light that reaches the polygon mirror 15 through the non-reflective sheet 23, the reflected light is absorbed or scattered by the non-reflective sheet 23 on the back side. As a result, the light does not reach the light receiving element 13. As a result, the detection accuracy can be improved.
  • FIG. 15 is a schematic diagram showing an embodiment of an optical scanning type touch panel.
  • the configuration is other than the optical units 1a and 1b, the retroreflective sheet 7, and the display screen 10 The members are not shown. Also, the case where a finger is used as the pointer S is shown.
  • the MPU 5 rotates each of the polygon mirrors 15 in the optical units 1a and 1b so that the laser light from each light emitting element 11 is rotated. Is scanned angularly. As a result, the reflected light from the retroreflective sheet 7 enters each light receiving element 13. In this way, the amount of light received by each light receiving element 13 is obtained as a light receiving signal output from the light receiving signal detection circuits 3a and 3b.
  • ⁇ 00 and ⁇ 00 indicate the angle from the scanning reference line to each light-receiving element
  • ⁇ 0 and ⁇ 0 indicate the angles from the scanning reference line to the end of the retroreflective sheet 7.
  • ⁇ 1 and 1 are the angles from the scanning reference line to the reference line end of the indicator S
  • 0 2 and 0 2 are the angles from the scanning reference line to the reference line and the opposite end of the indicator S, respectively. Is shown.
  • the indicator S in this example, The process of obtaining the coordinates of the center position (pointed position) of the finger will be described.
  • the position of the optical unit 1a is set to the origin 0, the right side and the upper side of the display screen 10 are set to the X axis and the Y axis, and the length of the reference line (optical unit 1 Let L be the distance between a and 1b). Further, the position of the optical unit 1b is assumed to be B.
  • the center point P (PX, Py) indicated by the pointer S on the display screen 10 is the point when the force is located at an angle of 6 » ⁇ from the optical unit la, lb to the X axis.
  • the values of the X coordinate P x and the Y coordinate P y of P can be obtained from the following equations (2) and (3), respectively, based on the principle of triangulation.
  • the average value of the angle is obtained, and the average value of the angle is substituted into the conversion formulas (2) and (3) of the triangulation to obtain the coordinates of the center point Pc, which is the designated position.
  • the orthogonal coordinates of the four points P1 to P4 are obtained from the scanning angle according to the conversion formulas (2) and (3) for triangulation, and the average of the coordinate values of the four points is calculated. Then, it is possible to obtain the coordinates of the center point Pc. It is also possible to determine the coordinates of the center point Pc, which is the designated position, in consideration of the parallax and the visibility of the designated position.
  • FIG. 18 is a timing chart showing the relationship between the received light signal from the received light signal detection circuit 3a and the scanning angle ⁇ and the scanning time T of the polygon mirror 15 in the optical unit 1a. . If the scanning angular velocity of the polygon mirror 15 is constant and the scanning angular velocity is ⁇ , the scanning angle ⁇ and the scanning time ⁇ have a proportional relationship as shown in the following equation (6). .
  • FIG. 19 is a schematic diagram showing the principle of measuring the diameter of the cross section of the pointer S.
  • D 1 and D 2 are the diameters of the cross section of the pointer S viewed from the optical units 1 a and 1 b, respectively.
  • the distance ⁇ P c (rl) from the position 0 (0, 0), B (L, 0) of the optical unit la, lb to the center point P c (P cx, P cy) of the pointer S , BP c (r 2) are obtained as in the following equations (9) and (10).
  • the dust proof structure is provided in the optical unit, external dust does not enter the optical unit and adhere to the internal optical members. Deterioration of the characteristics of the optical member can be prevented, and the position of the indicator can be accurately detected.
  • the reflected light from the retroreflector that minimizes the amount of light is made to enter the optical aperture almost perpendicularly, the reflected light that minimizes the amount of light can be efficiently received and the detection accuracy can be improved. Can be improved.
  • the scanning light emitted from the optical unit is specularly reflected by the optical aperture and enters the optical unit. This can be prevented, and the detection accuracy can be improved.
  • the inclination angle of the normal to the optical aperture surface with respect to the optical axis of the scanning light is set to be larger than half the viewing angle of the light receiving unit. Does not affect viewing angle restriction.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Human Computer Interaction (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Position Input By Displaying (AREA)

Abstract

Two optical units each incorporating an optical system which comprises a light-emitting element, a light-receiving element, and a polygon mirror are provided outside the respective corners of one short side of a rectangular display screen. A light beam is angularly scanned from each optical unit, and fraction of the reflected light of the scanning light beam from a retroreflecting sheet is received. The position at which the light beam is blocked by a pointing body is found based on the strength of the reflected light corresponding to the scanning angle. Each optical unit has a dustproof structure for preventing dust from entering its inside from the outside.

Description

明 糸田 書  Akira Itoda
光走査型タッチパネル  Optical scanning touch panel
技術分野 Technical field
本発明は、 表示画面上での指示物の位置を光学的に検出する光走 査型タツチパネルに関する。  The present invention relates to an optical scanning touch panel that optically detects the position of an indicator on a display screen.
背景技術 Background art
主と してパーソナルコ ンピュ一夕等のコ ンピュ一夕システムの普 及に伴って、 コ ンピュータシステムによ り情報が表示される表示装 置の表示画面上を人の指または特定の指示物によ り指示することに よ り、 新たな情報を入力したり、 コンピュータシステムに対して種 々の指示を与えたりする装置が利用されている。  With the spread of computer systems, such as personal computers, mainly, a human finger or a specific indicator is displayed on the display screen of a display device on which information is displayed by the computer system. Devices that input new information or give various instructions to a computer system by giving instructions are used.
パーソナルコンピュータ等の表示装置の表示画面に表示された情 報に対してタツチ方式にて入力操作を行う場合には、 その表示画面 上での接触位置 （指示位置） を高精度に検出する必要がある。 この ような座標面となる表示画面上の指示位置を検出する方法の一例と して、 光学的な位置検出方法が、 特開昭 6 2 — 5 4 2 8号公報等に 提案されている。 この方法は、 表示画面の両側枠に光再帰性反射体 を配置し、 角度走査したレーザ光線のこの光再帰性反射体からの戻 り光を検知し、 指またはペンによって光線が遮断されるタイ ミ ング から指またはペンの存在角度を求め、 求めた角度から三角測量の原 理にて位置座標を検出する。 この方法では、 部品点数が少なく て検 出精度を維持でき、 指， 任意のペン等の位置も検出できる。  When performing an input operation on the information displayed on the display screen of a display device such as a personal computer by a touch method, it is necessary to detect a contact position (designated position) on the display screen with high accuracy. is there. As an example of a method for detecting such a pointed position on a display screen serving as a coordinate plane, an optical position detection method has been proposed in Japanese Patent Application Laid-Open No. Sho 62-52428. In this method, light retroreflectors are arranged on both side frames of a display screen, a return light from the light retroreflector of the angle-scanned laser beam is detected, and a finger or a pen interrupts the light. The angle of the finger or pen is determined from the mining, and the position coordinates are detected from the obtained angle by the principle of triangulation. In this method, the number of parts is small, the detection accuracy can be maintained, and the position of a finger, an arbitrary pen, etc. can be detected.
このよ うな走査光によ り位置検出を行う光走査型タッチパネルは 一般的に表示画面の外側に設けられた再帰性反射体と、 レーザ光等 の光を出射する発光素子、 出射された光を角度走査するポリ ゴンミ ラー等の光走査部、 及び、 その走査光の再帰性反射体による反射光 を受光する受光素子を含む複数の光学ュニッ 卜 とを備えており、 各 光学ュニッ 卜において、 発光素子からの光を光走査部にて走査させ. その走査光の再帰性反射体での反射光を再び光走査部で反射させ、 その反射光を受光素子に受光させる構成を有している。 その走査光 の経路に指， 任意のペン等の指示物が存在する場合には、 再帰性反 射体での反射光が受光素子に受光されない。 そこで、 各光学ュニッ トにおける光走査部の走査角度及び受光素子での受光結果に基づい て、 それらの指示物の位置を検出する こ とができる。 An optical scanning type touch panel that performs position detection by using such scanning light generally includes a retroreflector provided outside the display screen, a light emitting element that emits light such as laser light, and a light emitting element that emits light. Polygon scanning angle scan And a plurality of optical units including a light receiving element for receiving the light reflected by the retroreflector of the scanning light, and the light from the light emitting element is transmitted to each optical unit. The light is scanned by the optical scanning unit. The light reflected by the retroreflector of the scanning light is reflected again by the optical scanning unit, and the reflected light is received by the light receiving element. If an indicator such as a finger or an arbitrary pen is present in the path of the scanning light, the light reflected by the retroreflector is not received by the light receiving element. Thus, based on the scanning angle of the optical scanning unit in each optical unit and the result of light reception by the light receiving element, the position of the pointing object can be detected.
このような光走査型タツチパネルにあっては、 例えば塵埃がポリ ゴンミ ラー等の光走査部に付着した場合、 その反射率が劣化して S / N比が低下し、 指示物の正確な位置を検出できなく なる。 また、 ポリ ゴンミ ラ一に限らず、 光学ュニッ ト内の他の光学部材について も、 その特性が劣化しないように、 外部の塵埃を付着させないよう にする必要がある。 しかしながち、 従来の光走査型タツチパネルで は、 この塵埃付着を防止する こ とが考慮されていない。  In such an optical scanning type touch panel, for example, when dust adheres to an optical scanning section such as a polygon mirror, the reflectance is deteriorated, the S / N ratio is reduced, and the accurate position of the indicator is determined. It cannot be detected. Also, not only the polygon mirror but also other optical members in the optical unit need to prevent external dust from adhering so that the characteristics are not deteriorated. However, in the conventional optical scanning type touch panel, no consideration is given to preventing this dust adhesion.
本発明は斯かる事情に鑑みてなされたものであ り、 防塵構造を光 学ュニッ 卜に備えるこ とによ り、 塵埃が光学ュニッ ト内の光学部材 に付着するこ とを防止でき、 光学部材の特性の劣化を抑えて、 指示 物の正確な位置検出を行える光走査型タ ツチパネルを提供するこ と を目的とする。 発明の開示  The present invention has been made in view of such circumstances, and by providing a dustproof structure in an optical unit, dust can be prevented from adhering to an optical member in the optical unit. An object of the present invention is to provide an optical scanning type touch panel capable of detecting a position of an indicator accurately while suppressing deterioration of characteristics of members. Disclosure of the invention
第 1発明の光走査型タッチパネルは、 所定領域の外側に設けた光 再帰性反射体と、 所定領域と実質的に平行である面内で光を角度走 査する光走査部及び光走査部による走査光の光再帰性反射体での反 射光を受光する受光部を有する複数の光学ュニッ 卜 とを備え、 その 所定領域に指示物で形成される走査光の遮断位置を走査角度に対応 した受光部の受光出力に基づいて検出する光走査型タッチパネルに おいて、 光学ュニッ トは、 その走査光の領域に光学的開口面を有す る防塵構造を備える。 An optical scanning type touch panel according to a first aspect of the present invention includes a light retroreflector provided outside a predetermined area, an optical scanning section for angularly scanning light in a plane substantially parallel to the predetermined area, and an optical scanning section. Anti-reflection of scanning light at the light retroreflector An optical unit having a plurality of optical units having a light receiving unit for receiving the emitted light, wherein an optical scanning unit detects a blocking position of the scanning light formed by the indicator in a predetermined area based on a light receiving output of the light receiving unit corresponding to the scanning angle. In the type touch panel, the optical unit has a dust-proof structure having an optical opening surface in the scanning light area.
第 1 発明の光走査型タッチパネルでは、 光学ュニッ トに防塵構造 が設けられており、 外部の塵埃が光学ュニッ ト内に入って内部の光 学部材に付着するこ とがない。 よって、 塵埃付着に伴う光学部材の 特性劣化が抑えられ、 指示物の位置検出の安定した動作が行われ、 指示物の正確な位置を検出できる。  In the optical scanning touch panel of the first invention, the optical unit has a dustproof structure, so that external dust does not enter the optical unit and adhere to the internal optical members. Therefore, characteristic deterioration of the optical member due to dust adhesion is suppressed, a stable operation for detecting the position of the pointer is performed, and an accurate position of the pointer can be detected.
第 2発明の光走査型タッチパネルは、 第 1発明において、 光学的 開口面の法線方向が、 反射光の光量が最小となる走査光の方向に実 質的に等しい。 第 2発明の光走査型タ ツチパネルでは、 光量が最小 となる再帰性反射体からの反射光が、 光学的開口面に略垂直に入射 される。 よって、 光量が最小となる反射光を効率良く受光でき、 検 出精度の向上を図れる。  In the optical scanning touch panel according to the second invention, in the first invention, the normal direction of the optical aperture surface is substantially equal to the direction of the scanning light at which the amount of reflected light is minimized. In the optical scanning touch panel according to the second aspect of the invention, the reflected light from the retroreflector with the minimum light quantity is incident on the optical aperture surface almost perpendicularly. Therefore, the reflected light with the minimum light amount can be efficiently received, and the detection accuracy can be improved.
第 3発明の光走査型タツチパネルは、 第 1発明において、 光学的 開口面の法線が、 走査光の光軸に対して傾斜している。 第 3発明の 光走査型タツチパネルでは、 光学的開口面の法線が、 走査光の光軸 に対して傾斜しており、 光学ュニッ トから出射された走査光が光学 的開口面で正反射されて光学ュニッ 卜に入射されるこ とを防止する, 第 4発明の光走査型タツチパネルは、 第 3発明において、 走査光 の光軸に対する法線の傾斜角が、 受光部の視野角の半分よ り大きい 第 4発明の光走査型タッチパネルでは、 走査光の光軸に対する光学 的開口面の法線の傾斜角が受光部の視野角の半分よ り大きく なつて おり、 受光部に視野角制限を行った場合にも、 その視野角制限に支 障を及ぼさない。 図面の簡単な説明 In the optical scanning touch panel according to a third aspect, in the first aspect, a normal line of the optical aperture surface is inclined with respect to an optical axis of the scanning light. In the optical scanning touch panel according to the third aspect of the present invention, the normal to the optical aperture is inclined with respect to the optical axis of the scanning light, and the scanning light emitted from the optical unit is specularly reflected at the optical aperture. According to the fourth aspect of the present invention, in the optical scanning type touch panel according to the third aspect, the inclination angle of a normal to the optical axis of the scanning light is less than half the viewing angle of the light receiving unit. In the optical scanning touch panel according to the fourth aspect of the invention, the inclination angle of the normal to the optical aperture surface with respect to the optical axis of the scanning light is larger than half the viewing angle of the light receiving section, and the viewing angle is limited for the light receiving section. Even if you go there, Does not interfere. BRIEF DESCRIPTION OF THE FIGURES
第 1 図は本発明の光走査型タッチパネルの基本構成を示す模式図、 第 2図は光学ュニッ トにおける光学系の構成及び光路を示す斜視図、 第 3図は光学ュニッ トにおける防塵構造を示す断面図、 第 4 図は光 学ュニッ トにおける防塵構造を示す側面図、 第 5図は防塵構造の取 付け工程を示す断面図、 第 6 図は防塵構造の取付け状態を示す断面 図、 第 7図は表示画面に対する走査光と入射角との関係を示す模式 図、 第 8図は可視光力ッ トフィルタにおける入射角と透過率との関 係を示すグラフ、 第 9図はポリ ゴンミラ一と光学的開口面との位置 関係を示す図、 第 1 0図は光学距離の関係を示す図、 第 1 i 図は視 野角の大きさを示す図、 第 1 2図は光学ュニッ 卜における防塵構造 の曲面部を示す断面図、 第 1 3図はノィズ光対策を施した光学ュニ ッ トの一例の構成図、 第 1 4 図はノィズ光対策を施した光学ュニッ トの他の例の構成図、 第 1 5 図は光走査型タッチパネルの実施状態 を示す模式図、 第 1 6図は座標検出のための三角測量の原理を示す 模式図、 第 1 7図は指示物及び遮断範囲を示す模式図、 第 1 8図は 受光信号と走査角度と走査時間との関係を示すタイ ミ ングチャー ト - 第 1 9 図は指示物の断面の直径の計測原理を示す模式図である。 発明を実施するための最良の形態  FIG. 1 is a schematic diagram showing a basic configuration of an optical scanning type touch panel of the present invention, FIG. 2 is a perspective view showing an optical system configuration and an optical path in an optical unit, and FIG. 3 is a dustproof structure in the optical unit. Sectional view, Fig. 4 is a side view showing the dustproof structure in the optical unit, Fig. 5 is a sectional view showing the process of mounting the dustproof structure, Fig. 6 is a sectional view showing the state of attachment of the dustproof structure, Fig. 7 The figure is a schematic diagram showing the relationship between the scanning light and the incident angle with respect to the display screen, FIG. 8 is a graph showing the relationship between the incident angle and the transmittance in the visible light power filter, and FIG. 9 is a diagram showing the relationship between the polygon mirror and the polygon mirror. A diagram showing the positional relationship with the optical aperture surface, FIG. 10 is a diagram showing the relationship between the optical distances, FIG. 1i is a diagram showing the magnitude of the viewing angle, and FIG. 12 is a dustproof structure in the optical unit. FIG. 13 is a cross-sectional view showing a curved surface portion of the optical system. FIG. 14 is a configuration diagram of another example of an optical unit with noise light countermeasures. FIG. 15 is a schematic diagram showing an implementation state of an optical scanning type touch panel. Fig. 16 is a schematic diagram showing the principle of triangulation for coordinate detection, Fig. 17 is a schematic diagram showing an indicator and a cut-off range, and Fig. 18 is a diagram showing the relationship between a received light signal, scanning angle, and scanning time. Timing chart shown-Fig. 19 is a schematic diagram showing the principle of measuring the diameter of the cross section of the pointer. BEST MODE FOR CARRYING OUT THE INVENTION
以下、 本発明をその実施例を示す図面を参照して具体的に説明す る。 第 1図は、 本発明の光走査型タッチパネルの基本構成を示す模 式図である。  Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments. FIG. 1 is a schematic diagram showing a basic configuration of an optical scanning type touch panel of the present invention.
第 1 図において参照符号 1 0 は、 パーソナルコ ン ピュータ等の電 子機器における C R Tまたはフラッ トディスプレイノ、"ネル （ P D Ρ , L C D , E L等） ， 投射型映像表示装置等の矩形状の表示画面であ り、 本実施例では P D P (ブラズマデイ スプレイ） の表示画面と し て構成されている。 In FIG. 1, reference numeral 10 denotes a power supply of a personal computer or the like. This is a rectangular display screen such as a CRT or flat display, “nel” (PD Ρ, LCD, EL, etc.) in a slave device, a projection type video display device, etc. In this embodiment, a display screen of a PDP (brass display) It is configured as
例えば指， ペン等である指示物 Sによ り タツチするための目標区 域と して規定された平面の範囲であるこの長方形の表示画面 1 0の 一つの短辺 （本実施例では右側の辺） の両隅の外側には、 発光素子 受光素子， ポリ ゴンミ ラー， 各種のレンズ等を含む光学系を内部に 有する光学ュニッ ト 1 a , 1 bがそれぞれ設けられている。 各光学 ュニッ ト 1 a , 1 b には、 外部からの塵埃の侵入を防いで内部の光 学系への塵埃付着を防止する防塵構造が設けられている。 この防塵 構造については、 後に詳述する。 また、 表示画面 1 0 の右側の辺を 除く 3辺、 つま り、 上下両側の辺及び左側の辺の外側には再帰性反 射体と しての再帰性反射シー ト 7が設けられている。  For example, one short side of this rectangular display screen 10 which is a range of a plane defined as a target area for touching with an indicator S such as a finger or a pen (in this embodiment, the right side of Optical units 1a and 1b each having an optical system including a light-emitting element, a light-receiving element, a polygon mirror, various types of lenses, and the like are provided outside the two corners of each side. Each of the optical units 1a and 1b is provided with a dustproof structure for preventing dust from entering from outside and preventing dust from adhering to the internal optical system. This dustproof structure will be described later in detail. A retroreflective sheet 7 as a retroreflector is provided on three sides except the right side of the display screen 10, that is, outside the upper and lower sides and the left side. .
第 2図は、 光学ュニッ ト 1 a， l b における光学系の構成及び光 路を示す斜視図である。 両光学ユニッ ト 1 a , 1 b は同じ光学系を 有している。 光学ユニッ ト l a， l b は、 赤外線レーザ光を出射す るレーザダイオー ド （ L D ) からなる発光素子 1 1 と、 発光素子 1 1 からのレ一ザ光を平行光にするためのコ リ メ一ショ ンレンズ 1 2 と、 再帰性反射シー ト 7からの反射光を受光するフォ トダイオー ド ( P D ) からなる受光素子 1 3 と、 受光素子 1 3 への入射光を制限 するためのス リ ツ ト 1 4 aを有するス リ ツ ト板 1 4 と、 発光素子 1 1 からのレーザ光を角度走査するための例えば 4角柱状のポリゴン ミ ラ一 1 5 と、 アパーチャ 1 6 a によ り コ リ メーシ ヨ ンレンズ 1 からポリゴンミ ラー 1 5への投射光を制限する と共に、 ポリゴンミ ラ一 1 5 を介した再帰性反射シー ト 7からの反射光を受光素子 1 3 側へ反射するアパーチャ ミ ラ一 1 6 と、 アパーチャ ミ ラ一 1 6 での 反射光を集束させるための集光レンズ 1 7 と、 ポリ ゴンミ ラ一 1 5 を回転させるモータ 1 8 と、 これらの各光学部材を取付け固定する ための光学ュニッ ト本体 1 9 とを備える。 FIG. 2 is a perspective view showing an optical system configuration and an optical path in the optical unit 1a, lb. Both optical units 1a and 1b have the same optical system. The optical units la and lb are a light emitting element 11 composed of a laser diode (LD) that emits infrared laser light and a collimator for converting laser light from the light emitting element 11 into parallel light. And a photo diode (PD) 13 for receiving light reflected from the retroreflective sheet 7 and a slit for limiting light incident on the light receiving element 13. A slit plate 14 having 14 a, a polygon mirror 15 having, for example, a quadrangular prism shape for angularly scanning a laser beam from the light emitting element 11, and an aperture 16 a are used to collimate. In addition to limiting the light projected from the measurement lens 1 to the polygon mirror 15, the light reflected from the retroreflective sheet 7 via the polygon mirror 15 is received by the light receiving element 13. An aperture mirror 16 that reflects to the side, a condenser lens 17 for converging the light reflected by the aperture mirror 16, a motor 18 that rotates the polygon mirror 15, An optical unit main body 19 for mounting and fixing each optical member is provided.
第 3 図， 第 4 図は、 各光学ュニッ ト 1 a , l b における防塵構造 を示す断面図， 側面図である。 光学ュニッ ト 1 a， 1 b内に、 上述 した光学系を覆う よ う に防塵カバー 2 0 が設けられている。 この防 塵カバー 2 0 は、 光学系を覆う内面に無反射処理を施したスチール 製である。 防塵カバ一 2 0 の内面での反射光がノイ ズ光となるこ と を防止するために、 この無反射処理は施されている。  Figures 3 and 4 are a cross-sectional view and a side view showing the dustproof structure of each optical unit 1a, 1b. A dustproof cover 20 is provided in the optical units 1a and 1b so as to cover the above-described optical system. The dust cover 20 is made of steel in which an inner surface covering the optical system is subjected to a non-reflection treatment. This anti-reflection treatment is applied to prevent the reflected light on the inner surface of the dust cover 20 from becoming noise light.
ポリ ゴン ミ ラー 1 5 からの走査光の出射領域には、 この防塵カバ 一 2 0 が設けられておらず、 その出射領域は光学的開口面 2 1 とな つている。 この光学的開口面 2 1 は、 光を透過させる材質であれば 良く 、 例えば透明ガラスで構成されている。  The emission area of the scanning light from the polygon mirror 15 is not provided with the dust cover 20, and the emission area is an optical aperture surface 21. The optical aperture surface 21 may be made of any material that transmits light, and is made of, for example, transparent glass.
本発明の光走査型タ ツチパネルでは、 このよ う な防塵構造によ り 完全に密閉構造となってお り、 外部からの塵埃の侵入を防止してい る。 よって、 この防塵構造にて、 光学ユニッ ト 1 a , l b内の光学 部材への塵埃の付着を防いでお り、 例えば、 ポリ ゴンミ ラー 1 5 , アパーチャ ミ ラー 1 6 の塵埃の付着に伴う反射率の劣化が起こ らず S / N比の低下を防止できる。  In the optical scanning touch panel of the present invention, such a dustproof structure provides a completely hermetic structure, thereby preventing dust from entering from the outside. Therefore, this dustproof structure prevents dust from adhering to the optical members in the optical units 1a and lb. For example, reflection caused by the dust adherence of the polygon mirror 15 and the aperture mirror 16 The deterioration of the S / N ratio can be prevented without deterioration of the rate.
次に、 この防塵構造 （防塵カバ一 2 0 ) の取付けについて、 第 5 図， 第 6 図を参照して説明する。 光学ュニッ ト本体 1 9 には、 ガイ ド用溝 2 2 が形成されてお り （第 5 図 （ a ) , 第 6 図） 、 このガイ ド用溝 2 2 に防塵カバ一 2 0 が挿入されるよ う になつている （第 5 図 （ b ) ， 第 6 図） 。 防塵カバ一 2 0 の先端部 2 0 aには引っ掛け ッメ構造が設けられてお り、 ガイ ド用溝 2 2 に対する防塵カバ一 2 0 の着脱処理を容易にしている。 ネジが不要であ り、 光軸調整等の メ ンテナンス性に優れている。 Next, the installation of the dustproof structure (dustproof cover 20) will be described with reference to FIGS. A guide groove 22 is formed in the optical unit main body 19 (FIGS. 5 (a) and 6), and a dust cover 20 is inserted into the guide groove 22. (Fig. 5 (b), Fig. 6). The tip 20a of the dustproof cover 20 is provided with a hooking structure, and the dustproof cover 2 for the guide groove 22 is provided. The process of attaching and detaching 0 is easy. No screws are required, and excellent maintenance such as optical axis adjustment is achieved.
このように本発明の防塵構造では、 防塵カバー 2 0 と光学ュニッ ト本体 1 9 とが位置決め機構 （ガイ ド用溝 2 2 ) でガイ ドされ、 し かも、 防塵カバ一 2 0及び光学ュニッ ト本体 1 9 が嵌合されている c よって、 外部からの塵埃の侵入を強固に防止している。 また、 この 防塵構造は光学ュニッ ト 1 a， 1 b に完全に内蔵されてお り、 防塵 構造を導入しても光学ュニッ ト 1 a , 1 b の大型化を引き起こさな い As described above, in the dustproof structure of the present invention, the dustproof cover 20 and the optical unit main body 19 are guided by the positioning mechanism (the guide groove 22), and the dustproof cover 20 and the optical unit The main body 19 is fitted to the connector c to prevent dust from entering from outside. In addition, this dustproof structure is completely built into the optical units 1a and 1b, and the dustproof structure does not increase the size of the optical units 1a and 1b.
発光素子 1 1 から出射されたレ一ザ光は、 コ リ メ一シヨ ンレンズ The laser light emitted from the light emitting element 11 is converted into a collimation lens.
1 2 にて平行光にされ、 アパーチャ ミ ラ一 1 6 のアパーチャ 1 6 a を通過した後、 ポリゴンミラー 1 5 の回転によって光学的開口面 2The light is collimated at 1 2, passes through the aperture 16 a of the aperture mirror 16, and is rotated by the polygon mirror 15 to form the optical aperture 2
1 を介して表示画面 1 0 と実質的に平行である面内を角度走査され て再帰性反射シ一 ト 7 に投射される。 そして、 再帰性反射シ一ト 7 からの反射光が、 ポリゴンミ ラー 1 5及びアパーチャ ミ ラ一 1 6 に て反射された後、 集光レンズ 1 7 で集束されてス リ ツ ト板 1 4 のス リ ツ ト 1 4 aを通って、 受光素子 1 3 に入射される。 但し、 走査光 の経路に指示物 Sが存在する場合には投射光が遮断されるため、 反 射光が受光素子 1 3 に入射されるこ とはない。 The light is angularly scanned in a plane substantially parallel to the display screen 10 through 1 and projected on the retroreflective sheet 7. Then, the reflected light from the retroreflective sheet 7 is reflected by the polygon mirror 15 and the aperture mirror 16, and then condensed by the condenser lens 17, and is reflected by the slit plate 14. The light passes through the slit 14 a and enters the light receiving element 13. However, when the pointer S is present in the scanning light path, the reflected light is not incident on the light receiving element 13 because the projected light is blocked.
各光学ュニッ ト 1 a， 1 b には、 各発光素子 1 1 を駆動する発光 素子駆動回路 2 a , 2 b と、 各受光素子 1 3 の受光量を電気信号に 変換する受光信号検出回路 3 a , 3 b と、 各ポリ ゴンミ ラー 1 5 の 動作を制御して各光学ユニッ ト l a , l b における光走査開始を同 期させる走査同期制御回路 4 とが接続されている。 また、 参照符号 Each optical unit 1a, 1b includes a light emitting element driving circuit 2a, 2b for driving each light emitting element 11, and a light receiving signal detecting circuit 3 for converting the amount of light received by each light receiving element 13 into an electric signal. a, 3b, and a scan synchronization control circuit 4 for controlling the operation of each polygon mirror 15 to synchronize the start of optical scanning in each of the optical units la, lb. Also, reference symbols
5 は指示物 Sの位置， 大きさを算出する と共に、 装置全体の動作を 制御する M P Uであ り、 6 は M P U 5 での算出結果等を表示する表 示装置である。 Reference numeral 5 denotes an MPU that calculates the position and size of the pointer S and controls the operation of the entire device. Reference numeral 6 denotes a table that displays the calculation results and the like of the MPU 5. Display device.
M P U 5 は、 発光素子駆動回路 2 a , 2 bに駆動制御信号を送り、 その駆動制御信号に応じて発光素子駆動回路 2 a， 2 bが駆動され て、 各発光素子 1 1 の発光動作が制御される。 受光信号検出回路 3 a , 3 b は、 各受光素子 1 3 での受光信号を M P U 5へ送る。 M P U 5 は、 各受光素子 1 3からの受光信号に基づいて、 指示物 Sの位 置， 大きさ を算出し、 その算出結果を表示装置 6 に表示する。 なお、 表示装置 6 は表示画面 1 0 を兼用するこ とも可能である。  The MPU 5 sends a drive control signal to the light-emitting element drive circuits 2a and 2b, and the light-emitting element drive circuits 2a and 2b are driven according to the drive control signals, so that the light-emitting operation of each light-emitting element 11 is performed. Controlled. The light receiving signal detection circuits 3 a and 3 b send the light receiving signals from the respective light receiving elements 13 to the MPU 5. The MPU 5 calculates the position and size of the pointer S based on the light receiving signal from each light receiving element 13 and displays the calculation result on the display device 6. The display device 6 can also serve as the display screen 10.
このような本発明の光走査型タツチパネルにおいては、 第 1 図に 示されているように、 例えば光学ュニッ ト l b に関して説明する と、 光学ュニッ ト 1 bからの投射光は、 受光素子 1 3 に入射する位置か ら第 1 図上で反時計方向回りに走査され、 再帰性反射シ一ト 7 の先 端部分で反射される位置 （ P s ) に至って実質的な走査開始位置に なる。 そして、 指示物 S の一端に至る位置 （ P 1 ) までは再帰性反 射シー ト 7によ り反射されるが、 指示物 Sの他端に至る位置 （ P 2 ) までの間は指示物 S によって遮断され、 その後の走査終了位置 （ P e ) に至るまでは再帰性反射シー ト 7 によ り反射される。  In such an optical scanning type touch panel according to the present invention, as shown in FIG. 1, for example, with respect to the optical unit lb, the light projected from the optical unit 1b is applied to the light receiving element 13 as shown in FIG. From the incident position, scanning is performed in the counterclockwise direction on FIG. 1, and the position (P s) where the light is reflected at the leading end of the retroreflective sheet 7 is a substantial scanning start position. Then, the light is reflected by the reflexive reflection sheet 7 up to the position (P 1) reaching one end of the pointer S, but is reflected up to the position (P 2) reaching the other end of the pointer S. The light is blocked by S and is reflected by the retroreflective sheet 7 until reaching the subsequent scanning end position (P e).
次に、 光学的開口面 2 1 の設置例について説明する。 第 7図は、 走査光と入射角との関係を示す模式図である。 第 7図で実線で示す ように、 光学ュニッ ト 1 aの設置位置と対角関係になる位置 （再帰 性反射シー ト 7への入射角が最大の 6 0度となる位置） を走査する 場合に、 再帰性反射シー ト 7からの反射光が最も小さ く なる。 この 反射光が最も小さ く なる走査光の方向に、 その法線方向が一致また は略一致するように、 光学的開口面 2 1 を設けている。 よって、 反 射光が最も小さ く なる場合に、 光学的開口面 2 1 の透過率が最も良 く なり、 S / N比の低下を防ぐこ とができる。 外乱可視光の入射を抑制するために、 光学的開口面 2 1 と して可 視光力 ッ ト フ ィ ルタを用いた場合について説明する。 第 8図は、 可 視光カ ツ トフィルタにおける入射角と透過率との関係を示すグラフ である。 第 8図から、 入射角 0度近傍で透過率が最大になることが 分かる。 よって、 この可視光カ ッ トフィルタからなる光学的開口面 2 1 に反射光が入射角略 0度で入射した場合に透過率が最大になる ので、 この方向に反射光が最小となる位置 （再帰性反射シー ト 7へ の入射角が最大となる位置） を一致させる と、 S /N比が良く なる この場合には、 光学的開口面 2 1 の法線方向を走査角 6 0度とする また、 第 8図よ り ± 4 5度の入射角の範囲で所定以上の透過率が得 られるので、 光学的開口面 2 1 の法線方向を 4 5度または略 4 5度 に設定する こ とによ り、 全走査範囲内 （走査角度 0 〜 9 0度） で所 定値以上の透過率を確保するこ とができる。 Next, an example of setting the optical aperture surface 21 will be described. FIG. 7 is a schematic diagram showing a relationship between scanning light and an incident angle. As shown by the solid line in Fig. 7, when scanning at a position that is diagonally related to the installation position of the optical unit 1a (the position at which the incident angle to the retroreflective sheet 7 is the maximum of 60 degrees) In addition, the reflected light from the retroreflective sheet 7 is minimized. The optical aperture surface 21 is provided so that the direction of the scanning light at which the reflected light is minimized coincides or substantially coincides with the normal direction. Therefore, when the reflected light is minimized, the transmittance of the optical aperture surface 21 is maximized, and a decrease in the S / N ratio can be prevented. A description will be given of a case where a visible light power filter is used as the optical aperture surface 21 in order to suppress the incidence of disturbance visible light. FIG. 8 is a graph showing a relationship between an incident angle and a transmittance in a visible light cut filter. From FIG. 8, it can be seen that the transmittance becomes maximum near the incident angle of 0 degree. Therefore, when the reflected light is incident on the optical aperture surface 21 formed of the visible light cut filter at an incident angle of approximately 0 degree, the transmittance becomes maximum, and the position where the reflected light becomes minimum in this direction ( When the angle of incidence on the retroreflective sheet 7 is maximized), the S / N ratio is improved. In this case, the normal direction of the optical aperture surface 21 is set to a scanning angle of 60 degrees. In addition, as shown in FIG. 8, a transmittance higher than a predetermined value can be obtained in the range of an incident angle of ± 45 degrees, so that the normal direction of the optical aperture surface 21 is set to 45 degrees or approximately 45 degrees. As a result, it is possible to secure a transmittance higher than a predetermined value within the entire scanning range (scan angle 0 to 90 degrees).
と ころで、 上述したように、 光学的開口面 2 1 の透過率の観点か ら考える と、 光学的開口面 2 1 の法線方向をポリ ゴンミラ一 1 5か らの走査光の光軸方向に一致させるこ とが最適であるが、 このよう に設定する と、 ポリゴンミ ラー 1 5からの走査光の一部がこの光学 的開口面 2 1 で正反射してポリ ゴンミ ラ一 1 5 に戻ってきてノイズ となる可能性がある。 例えば、 光電変換効率 0 . 5 A /W, 電流電 圧変換定数 I X 1 0 6 ( V / A ) 倍の電気回路を使用した場合、 受 光素子 1 3 での受光可能最低信号レベルを 0 . 2 V と したとき、 そ れは 0 . 4 W ( = 0 . 2 ÷ ( 1 X 1 0 6 X 0 . 5 ) ) の光量に相 当する。 発光素子 1 1 での発光パワーを 1 0 0 i Wと した場合、 こ れは 0 . 4 %の反射光量に相当する。 よって、 光学的開口面 2 1 に おける正反射の反射率が 0 . 4 %であっても、 受光信号に大きな影 響を及ぼすこ とが分かる。 1 O By the way, as described above, from the viewpoint of the transmittance of the optical aperture surface 21, the normal direction of the optical aperture surface 21 is the direction of the optical axis of the scanning light from the polygon mirror 15. Although it is best to match the angle, a part of the scanning light from the polygon mirror 15 is specularly reflected on the optical aperture surface 21 and returns to the polygon mirror 15 with this setting. Noise may occur. For example, the photoelectric conversion efficiency 0. 5 A / W, when using a current voltage conversion constant IX 1 0 6 (V / A ) times the electric circuit, the light receivable minimum signal level at the light receiving element 1 3 0. when the 2 V, its Re is 0. 4 W (= 0. 2 ÷ (1 X 1 0 6 X 0. 5)) is equivalent to the amount of light of. If the light emission power of the light emitting element 11 is 100 iW, this corresponds to a reflected light amount of 0.4%. Therefore, it can be seen that even if the reflectance of the specular reflection on the optical aperture surface 21 is 0.4%, it greatly affects the received light signal. 1 O
そこで、 本発明では、 第 9図に示すよ う にして、 光学的開口面 2 1 での正反射成分の影響をなくすようにする。 光学的開口面 2 1 の 法線が、 走査光の光軸に対して上方向または下方向に倒れるように して、 光学的開口面 2 1 での正反射光を受光素子 1 3 で受光しない ようにしている。 第 9図に示す例では、 走査光の光軸 （実線 A ) か ら、 光学的開口面 2 1 の法線方向 （破線 B ) が上方向に角度 ε / 2 だけ倒れるように光学的開口面 2 1 を設定している。 このようにし ておく と、 ポリ ゴンミ ラ一 1 5からの走査光の光学的開口面 2 1 に よる正反射光は、 入射光軸 （実線 Α ) から上方向に角度 εだけ離れ た方向 （実線 C ) に進み、 ポリ ゴンミラ一 1 5 を介して受光素子 1 3 に受光されない。 なお、 この角度 ε / 2 を開口面倒れ角という。 次に、 この開口面倒れ角の設定について考察する。 光学的開口面 2 1 からの正反射光が受光素子 1 3 に入射されないためには、 第 1 0図に示すように、 アパーチャ ミ ラー 1 6から受光レンズ 1 7まで の距離を D、 アパーチャ ミ ラ一 1 6 からポリ ゴン ミ ラー 1 5 までの 距離をし、 ポリ ゴンミ ラ一 1 5から光学的開口面 2 1 までの距離を d L、 受光レンズ 1 7の半径を B とした場合、 以下の条件 （ 1 ) を 満たすようにすれば良い。 このような条件 （ 1 ) を満たすように開 口面倒れ角を設定するこ とによ り、 上述したような正反射の影響を なく すこ とが可能である。  Thus, in the present invention, as shown in FIG. 9, the influence of the specular reflection component on the optical aperture surface 21 is eliminated. The specular light from the optical aperture surface 21 is not received by the light receiving element 13 so that the normal line of the optical aperture surface 21 falls upward or downward with respect to the optical axis of the scanning light. Like that. In the example shown in FIG. 9, the optical aperture surface is such that the normal direction (dashed line B) of the optical aperture surface 21 is inclined upward by an angle ε / 2 from the optical axis (solid line A) of the scanning light. 2 1 is set. By doing so, the specular reflection light of the scanning light from the polygon mirror 15 on the optical aperture surface 21 is directed away from the incident optical axis (solid line Α) by an angle ε upward (solid line). Proceed to C), and the light is not received by the light receiving element 13 via the polygon mirror 15. Note that this angle ε / 2 is called the opening plane inclination angle. Next, the setting of the opening plane inclination angle will be considered. In order to prevent specularly reflected light from the optical aperture surface 21 from being incident on the light receiving element 13, as shown in FIG. 10, the distance from the aperture mirror 16 to the light receiving lens 17 is D, and the aperture Assuming that the distance from the polygon mirror 16 to the polygon mirror 15 is dL, the distance from the polygon mirror 15 to the optical aperture surface 21 is d L, and the radius of the light receiving lens 17 is B, Condition (1) should be satisfied. By setting the inclination angle of the opening face so as to satisfy the condition (1), it is possible to eliminate the above-described influence of the regular reflection.
t a n - 1 ( B / ( D + L + d L ) ) < ε … ( 1 ) この開口面倒れ角の設定の具体例について説明する。 第 1 1 図に 示すように、 再帰性反射シー ト 7 の幅を 1 5 mmと した場合、 そこ から 1 5 0 0 m m離れた受光レンズ 1 7が設けられている位置での 視野角土 Θ は以下のようになる。 tan- 1 (B / (D + L + dL)) <ε (1) A specific example of the setting of the opening plane inclination angle will be described. As shown in FIG. 11, when the width of the retroreflective sheet 7 is set to 15 mm, the viewing angle at the position where the light receiving lens 17 is provided at a distance of 150 mm from the retroreflective sheet 7 is set. Is as follows.
± 6 = ± t a n— ' ( 7 . 5 / 1 5 0 0 ) = ± 0 . 2 8 6 (度） ± 6 = ± tan— '(7.5 / 150 0) = ± 0.26 (degrees)
従って、 光学的開口面 2 1 の開口面倒れ角 （ ε / 2 ) を 0 . 3度 に設定する と、 その値は、 視野角土 Θ の 1 / 2 ( = ± 0 . 1 4 3 ) よ り も大き く なり、 正反射の影響を防止できる。 また、 光学的開口 面 2 1 におけるこの程度の大きさの倒れでは、 ε / 2 が 0 に近いの で、 その透過率はほとんど減衰せず、 透過率について問題とならな い  Therefore, if the opening plane inclination angle (ε / 2) of the optical opening surface 21 is set to 0.3 degrees, the value is 1/2 of the viewing angle soil (= ± 0.143). And the effect of specular reflection can be prevented. In addition, when ε / 2 is close to 0, the transmittance is hardly attenuated in the optical aperture surface 21 with such a degree of inclination, and the transmittance is not a problem.
以下、 本発明の他の実施例について説明する。 7 0 0 n m以上の 波長域の光を選択的に透過する特性を持つ樹脂製の可視光力ッ トフ ィルタにて、 防塵カバ一 2 0 を構成する。 このようにした場合には、 防塵機能に加えて、 蛍光灯， 白熱灯等からの外乱光を遮断する機能 も果たせる。  Hereinafter, another embodiment of the present invention will be described. The dustproof cover 20 is made up of a resin-made visible light power filter having a characteristic of selectively transmitting light in a wavelength range of 700 nm or more. In such a case, in addition to the dust-proof function, a function of blocking disturbance light from fluorescent lamps, incandescent lamps, and the like can be performed.
樹脂製の可視光力ッ トフィルタ材料に赤外線反射膜を塗布して作 製され、 発光素子 1 1からのレーザ光と同じ波長域の光のみを選択 的に透過する樹脂製のバン ドバスフィルタにて、 防塵カバ一 2 0 を 構成する。 このようにした場合には、 防塵機能に加えて、 蛍光灯， 白熱灯等からの外乱光を遮断する機能も果たせる。  It is made by applying an infrared reflective film to a resin visible light power filter material, and is a resin band-pass filter that selectively transmits only light in the same wavelength range as the laser light from the light emitting element 11. To form the dust cover 20. In this case, in addition to the dust-proof function, a function of blocking disturbance light from fluorescent lamps, incandescent lamps, and the like can be performed.
光学的開口面 2 1 に反射防止膜を設ける。 このよ うにした場合に は、 光学的開口面 2 1 での反射が抑制され、 正反射の影響をなくす こ とができる。  An antireflection film is provided on the optical aperture surface 21. In this case, reflection at the optical aperture surface 21 is suppressed, and the influence of regular reflection can be eliminated.
第 1 2図は、 光学ュニッ ト i a， l b の断面図であり、 防塵構造 (防塵カバ一 2 0 ) は、 ポリ ゴンミ ラー 1 5 を覆う部分が曲面部と なっており、 その曲面部の形状は、 ポリ ゴンミ ラ一 1 5 の外接円 （ 第 1 2図に破線で示す） と同心円状になっている。 よって、 ポリゴ ンミ ラ一 1 5 の回転によって生じる気流を滑らかにできる。 この結 果、 気流音の発生を低減できるので、 騒音対策となる。 アパーチャ ミ ラ一 i 6 からの拡散光が防塵カバー 2 0 の内面で反 射してノイ ズ光とな り、 そのノイズ光がポリ ゴン ミ ラー 1 5 まで到 達して、 正確な検出処理を行えない可能性がある。 よって、 以下の よ う な構成にして、 ノイズ光の影響をな く す。 Fig. 12 is a sectional view of the optical unit ia, lb. In the dustproof structure (dustproof cover 20), the portion covering the polygon mirror 15 is a curved surface, and the shape of the curved surface is Is concentric with the circumcircle of the polygon mirror 15 (indicated by the dashed line in Fig. 12). Therefore, the airflow generated by the rotation of the polygon mirror 15 can be made smooth. As a result, the generation of airflow noise can be reduced, which is a measure against noise. The diffused light from the aperture mirror i6 is reflected on the inner surface of the dust cover 20 to become noise light, and the noise light reaches the polygon mirror 15 to perform accurate detection processing. May not be. Therefore, use the following configuration to eliminate the influence of noise light.
第 1 3 図は、 このよ う なノィズ光対策を施した光学ュニッ トのー 例の構成図である。 アパーチャ ミ ラ一 1 6 からポリ ゴンミ ラ一 1 5 へ向かう光路に平行に沿わせた態様で、 防塵カバー 2 0 の内面に無 反射シー ト 2 3 が設けられている。 よって、 ノイ ズ光となるァパ一 チヤ ミ ラ一 1 6 からの拡散光は、 この無反射シ一 ト 2 3 で吸収また は散乱されて、 ポリ ゴンミ ラ一 1 5 まで到達しない。 この結果、 検 出精度の向上を図れる。  FIG. 13 is a configuration diagram of an example of an optical unit in which such noise light countermeasures are taken. A non-reflective sheet 23 is provided on the inner surface of the dust cover 20 so as to extend parallel to the optical path from the aperture mirror 16 to the polygon mirror 15. Therefore, the diffused light from the aperture mirror 16 serving as noise light is absorbed or scattered by the non-reflection sheet 23 and does not reach the polygon mirror 15. As a result, detection accuracy can be improved.
第 1 4 図は、 このよ う なノィズ光対策を施した光学ュニッ トの他 の例の構成図である。 ポリ ゴンミ ラ一 1 5 の外接円の近傍まで防塵 カバー 2 0 が突出してお り、 その突出部 2 O b の表面 （アパーチャ ミ ラ一 1 6側の面） 及び裏面 （ポリ ゴン ミ ラー 1 5側の面） に無反 射シー ト 2 3 が設けられている。 よって、 ノイズ光となるァパーチ ャ ミ ラ一 1 6 からの拡散光は、 この表面側の無反射シー ト 2 3 で吸 収または散乱されて、 ポリ ゴンミ ラー 1 5 まで到達しない。 また、 この無反射シー ト 2 3 の緣を通ってポリ ゴン ミ ラー 1 5 に到達する ノイズ光が存在した場合でも、 その反射光は、 この裏面側の無反射 シー ト 2 3 で吸収または散乱されて、 受光素子 1 3 まで到達しない, この結果、 検出精度の向上を図れる。  FIG. 14 is a configuration diagram of another example of an optical unit having such noise light countermeasures. The dust cover 20 protrudes to the vicinity of the circumscribed circle of the polygon mirror 15, and the surface (the surface on the aperture mirror 16 side) and the rear surface (the surface of the polygon mirror 15) of the protrusion 2 Ob A non-reflective sheet 23 is provided on the side surface). Therefore, the diffused light from the aperture mirror 16 serving as noise light is absorbed or scattered by the non-reflective sheet 23 on the surface side, and does not reach the polygon mirror 15. Also, even if there is noise light that reaches the polygon mirror 15 through the non-reflective sheet 23, the reflected light is absorbed or scattered by the non-reflective sheet 23 on the back side. As a result, the light does not reach the light receiving element 13. As a result, the detection accuracy can be improved.
最後に、 本発明の光走査型タ ツチパネルによる指示物 Sの位置， 大きさの算出動作について説明する。 第 1 5 図は、 光走査型タ ツチ パネルの実施状態を示す模式図である。 但し、 第 1 5 図では光学ュ ニッ ト 1 a， 1 b、 再帰性反射シー ト 7 , 表示画面 1 0以外の構成 部材は図示を省略している。 また、 指示物 S と して指を用いた場合 を示している。 Finally, the operation of calculating the position and size of the pointer S by the optical scanning touch panel of the present invention will be described. FIG. 15 is a schematic diagram showing an embodiment of an optical scanning type touch panel. However, in Fig. 15 the configuration is other than the optical units 1a and 1b, the retroreflective sheet 7, and the display screen 10 The members are not shown. Also, the case where a finger is used as the pointer S is shown.
M P U 5 はポリ ゴン制御回路 4 を制御する こ とによ り、 光学ュニ ッ ト 1 a , 1 b内の各ポリ ゴンミラ一 1 5 を回転させて、 各発光素 子 1 1 からのレーザ光を角度走査する。 この結果、 再帰性反射シ一 ト 7からの反射光が各受光素子 1 3 に入射する。 このよ う にして各 受光素子 1 3 に入射した光の受光量は受光信号検出回路 3 a， 3 b の出力である受光信号と して得られる。  By controlling the polygon control circuit 4, the MPU 5 rotates each of the polygon mirrors 15 in the optical units 1a and 1b so that the laser light from each light emitting element 11 is rotated. Is scanned angularly. As a result, the reflected light from the retroreflective sheet 7 enters each light receiving element 13. In this way, the amount of light received by each light receiving element 13 is obtained as a light receiving signal output from the light receiving signal detection circuits 3a and 3b.
なお、 第 1 5 図において、 Θ 00 , ø 00は走査基準線から各受光素 子までの角度を、 Θ 0 ， ø 0 は走査基準線から再帰性反射シート 7 の端部までの角度を、 Θ 1 , 1 は走査基準線から指示物 Sの基準 線側端部までの角度を、 0 2 ， 0 2 は走査基準線から指示物 Sの基 準線と逆側端部までの角度をそれぞれ示している。  In FIG. 15, Θ00 and ø00 indicate the angle from the scanning reference line to each light-receiving element, and Θ0 and ø0 indicate the angles from the scanning reference line to the end of the retroreflective sheet 7. Θ 1 and 1 are the angles from the scanning reference line to the reference line end of the indicator S, and 0 2 and 0 2 are the angles from the scanning reference line to the reference line and the opposite end of the indicator S, respectively. Is shown.
表示画面 1 0上の走査光の光路に指示物 Sが存在する場合には、 光学ュニッ ト 1 a， 1 bから投射された光の指示物 Sからの反射光 は各受光素子 1 3 に入射されない。 従って、 第 1 5 図に示されてい るような状態では， 走査角度が 0 ° から Θ 0 までの間では光学ュニ ッ ト 1 a内の受光素子 1 3 には反射光は入射されず、 走査角度が Θ 0から θ 1 までの間ではその受光素子 1 3 に反射光が入射され、 走 査角度が θ 1 から Θ 2 までの間ではその受光素子 1 3 に反射光が入 射されない。 同様に、 走査角度が 0 ° から ø 0 までの間では光学ュ ニッ ト l b内の受光素子 1 3 には反射光は入射されず、 走査角度が ø 0 から ø 1 までの間ではその受光素子 1 3 に反射光が入射され、 走査角度が ø 1 から 0 2 までの間ではその受光素子 1 3 に反射光が 入射されない。 If there is the indicator S on the optical path of the scanning light on the display screen 1 0 enters the optical Yuni' preparative 1 a, 1 light reflected from the indicator S of the projected light from the b is the light receiving element 1 3 Not done. Therefore, in the state as shown in Fig. 15, no reflected light is incident on the light receiving element 13 in the optical unit 1a when the scanning angle is between 0 ° and Θ0, When the scanning angle is between Θ0 and θ1, reflected light is incident on the light receiving element 13, and when the scanning angle is between θ1 and Θ2, reflected light is not incident on the light receiving element 13. Similarly, when the scanning angle is between 0 ° and ø0, no reflected light is incident on the light receiving element 13 in the optical unit lb, and when the scanning angle is between ø0 and ø1, the light receiving element is not. The reflected light is incident on 13 and the reflected light is not incident on the light receiving element 13 when the scanning angle is between ø1 and 02.
次に、 このよ う にして求めた遮断範囲から、 指示物 S (本例では 指） の中心位置 （指示位置） の座標を求める処理について説明する。 まず、 三角測量に基づく角度から直交座標への変換を説明する。 第 1 6図に示すように、 光学ュニッ ト 1 aの位置を原点 0、 表示画面 1 0の右辺， 上辺を X軸， Y軸に設定し、 基準線の長さ （光学ュニ ッ ト 1 a， 1 b間の距離） を Lとする。 また、 光学ュニッ ト 1 bの 位置を Bとする。 表示画面 1 0上の指示物 Sが指示した中心点 P ( P X , P y) 力 、 光学ユニッ ト l a, l bから X軸に対して 6», øの角度でそれぞれ位置している場合、 点 Pの X座標 P x， Y座標 P yの値は、 三角測量の原理により、 それぞれ以下の （ 2) ， （ 3 ) 式のように求めることができる。 Next, the indicator S (in this example, The process of obtaining the coordinates of the center position (pointed position) of the finger will be described. First, the conversion from angles to rectangular coordinates based on triangulation will be described. As shown in Fig. 16, the position of the optical unit 1a is set to the origin 0, the right side and the upper side of the display screen 10 are set to the X axis and the Y axis, and the length of the reference line (optical unit 1 Let L be the distance between a and 1b). Further, the position of the optical unit 1b is assumed to be B. The center point P (PX, Py) indicated by the pointer S on the display screen 10 is the point when the force is located at an angle of 6 », ø from the optical unit la, lb to the X axis. The values of the X coordinate P x and the Y coordinate P y of P can be obtained from the following equations (2) and (3), respectively, based on the principle of triangulation.
P X ( θ , φ ) = ( t a n ) ÷ ( t a n 0 + t a n 0) x L  P X (θ, φ) = (t a n) ÷ (t a n 0 + t a n 0) x L
… ( 2 ) … (2)
P y ( 0 , 0) = ( t a n ^ - t a n 0) ÷ P y (0, 0) = (t a n ^-t a n 0) ÷
( t a n 0 + t a n 0) x L ··· ( 3 ) ところで、 指示物 S (指） には大きさがあるので、 検出した受光 信号の立ち上がり Z立ち下がりのタイ ミ ングでの検出角度を採用し た場合、 第 1 7図に示すように、 指示物 S (措） のエッジ部の 4点 (第 1 7図の P 1〜P 4 ) を検出するこ とになる。 これらの 4点は 何れも指示した中心点 （第 1 7図の P c ) とは異なっている。 そこ で、 以下のようにして 中心点 P cの座標 （ P c X , P c y) を求 める。 P c x， P c yは、 それぞれ以下の （ 4 ) , ( 5 ) 式のよう に： 21せる。  (tan 0 + tan 0) x L (3) By the way, since the indicator S (finger) has a size, the detection angle at the timing of the rise Z and fall of the detected light reception signal is adopted. In this case, as shown in FIG. 17, four points (P1 to P4 in FIG. 17) at the edge of the pointer S (measure) are detected. These four points are all different from the designated center point (Pc in Fig. 17). Then, the coordinates (PcX, Pcy) of the center point Pc are obtained as follows. P cx and P cy are given by the following equations (4) and (5), respectively:
P c X ( 0 φ ) = P c X { θ \ + ά θ/ 2 ø 1 + d ø / 2 )  P c X (0 φ) = P c X (θ \ + ά θ / 2 ø 1 + d ø / 2)
… ( ) … ()
P c y ( θ , φ ) = Ρ c y ( θ I + ά θ ø 1 + d ø / 2 ) P c y (θ, φ) = Ρ c y (θ I + ά θ ø 1 + d ø / 2)
… ( 5 ) そこで、 （ 4 ) ， （ 5 ) 式で表される e i + d 6 / 2 ， （}i) l + d 0 / 2 を上記 （ 2 ) ， （ 3 ) 式の Θ , と して代入するこ とによ り - 指示された中心点 P cの座標を求めるこ とができる。 … ( Five ) Therefore, ei + d 6/2 and (} i) l + d 0/2 expressed by equations (4) and (5) are substituted as Θ in equations (2) and (3) above. By the above, the coordinates of the designated center point Pc can be obtained.
なお、 上述した例では、 最初に角度の平均値を求め、 その角度の 平均値を三角測量の変換式 （ 2 ) ， （ 3 ) に代入して、 指示位置で ある中心点 P cの座標を求めるようにしたが、 最初に三角測量の変 換式 （ 2 ) ， ( 3 ) に従って走査角度から 4点 P 1〜P 4 の直交座 標を求め、 求めた 4点の座標値の平均を算出して、 中心点 P cの座 標を求めるようにするこ とも可能である。 また、 視差、 及び、 指示 位置の見易さを考慮して、 指示位置である中心点 P cの座標を決定 するこ と も可能である。  In the example described above, first, the average value of the angle is obtained, and the average value of the angle is substituted into the conversion formulas (2) and (3) of the triangulation to obtain the coordinates of the center point Pc, which is the designated position. First, the orthogonal coordinates of the four points P1 to P4 are obtained from the scanning angle according to the conversion formulas (2) and (3) for triangulation, and the average of the coordinate values of the four points is calculated. Then, it is possible to obtain the coordinates of the center point Pc. It is also possible to determine the coordinates of the center point Pc, which is the designated position, in consideration of the parallax and the visibility of the designated position.
と ころで、 各ポリ ゴンミラ一 1 5 の走査角速度が一定である場合 には、 時間を計時するこ とによ り走査角度の情報を得るこ とができ る。 第 1 8図は、 受光信号検出回路 3 aからの受光信号と、 光学ュ ニッ ト 1 a内のポリ ゴンミラ一 1 5 の走査角度 Θ及び走査時間 Tと の関係を示すタイ ミ ングチャー トである。 ポリ ゴンミ ラー 1 5 の走 査角速度が一定である場合、 その走査角速度を ωとする と、 走査角 度 Θ及び走査時間 Τには、 下記 （ 6 ) 式に示すような比例関係が成 り立つ。  When the scanning angular velocity of each polygon mirror 15 is constant, information on the scanning angle can be obtained by measuring the time. FIG. 18 is a timing chart showing the relationship between the received light signal from the received light signal detection circuit 3a and the scanning angle の and the scanning time T of the polygon mirror 15 in the optical unit 1a. . If the scanning angular velocity of the polygon mirror 15 is constant and the scanning angular velocity is ω, the scanning angle Θ and the scanning time Τ have a proportional relationship as shown in the following equation (6). .
θ = ω X Τ … （ 6 )  θ = ω X… (6)
よって、 受光信号の立ち下がり， 立ち上がり時の角度 Θ 1 ， Θ 2 は、 それぞれの走査時間 t 1 , t 2 と下記 （ 7 ) , ( 8 ) 式の関係 が成り立つ。  Therefore, the relationship between the scanning times t 1 and t 2 and the following equations (7) and (8) holds for the angles Θ 1 and Θ 2 at the time of the falling and rising of the light receiving signal.
θ 1 = ω X t 1 … （ 7 )  θ 1 = ω X t 1… (7)
Θ 2 = ω X t 2 … （ 8 )  Θ 2 = ω X t 2… (8)
従って、 ポリ ゴンミラ一 1 5 の走査角速度が一定である場合には 時間情報を用いて、 指示物 S (指） の遮断範囲及び座標位置を計測 するこ とが可能である。 Therefore, when the scanning angular velocity of the polygon mirror 15 is constant, Using the time information, it is possible to measure the blocking range and coordinate position of the pointer S (finger).
また、 本発明の光走査型夕ツチパネルでは、 計測した遮断範囲か ら指示物 S (指） の大きさ （断面の直径） を求めることも可能であ る。 第 1 9図は、 この指示物 Sの断面の直径の計測原理を示す模式 図である。 第 1 9図において、 D 1， D 2はそれぞれ光学ュニッ ト 1 a , 1 bから見た指示物 Sの断面の直径である。 まず、 光学ュニ ッ ト l a , l bの位置 0 ( 0， 0 ) ， B ( L， 0 ) から指示物 Sの 中心点 P c ( P c x, P c y ) までの距離〇 P c ( r l ) , B P c ( r 2 ) が、 下記 （ 9 ) , ( 1 0 ) 式の如く求められる。  In the optical scanning type touch panel of the present invention, it is also possible to obtain the size (diameter of cross section) of the indicator S (finger) from the measured blocking range. FIG. 19 is a schematic diagram showing the principle of measuring the diameter of the cross section of the pointer S. In FIG. 19, D 1 and D 2 are the diameters of the cross section of the pointer S viewed from the optical units 1 a and 1 b, respectively. First, the distance 〇 P c (rl) from the position 0 (0, 0), B (L, 0) of the optical unit la, lb to the center point P c (P cx, P cy) of the pointer S , BP c (r 2) are obtained as in the following equations (9) and (10).
O P c = r l = ( P c x 2 + P c y 2 ) 1/2 - ( 9 )OP c = rl = (P cx 2 + P cy 2 ) 1/ 2- (9)
B P c = r 2 = { ( L一 P c x ) 2 + P c y 2 } 1/2 … （ 1 0 ) 指示物 Sの断面の半径が中心点までの距離と遮断角度の半分の正 弦値との積で近似できるので、 各断面の直径 D 1 , D 2は、 下記 ( 1 1 ) , ( 1 2 ) 式に従って計測可能である。 BP c = r 2 = {(L-P cx) 2 + P cy 2 } 1/2 … (1 0) Therefore, the diameters D 1 and D 2 of each cross section can be measured according to the following equations (1 1) and (1 2).
D l = 2 - r l - s i n ( d ^/ 2 )  D l = 2-r l-s i n (d ^ / 2)
= 2 ( P c x 2 + P c y 2 ) 1/2 - s i n ( ά θ 2 ) = 2 (P cx 2 + P cy 2 ) 1/ 2- sin (ά θ 2)
- ( 1 1 )
Figure imgf000018_0001
-(1 1)
Figure imgf000018_0001
= 2 { (L - P c x) 2 + P c y 1/2 = 2 {(L-P cx) 2 + P cy 1/2
- s i n ( ά φ / 2 ) - ( 1 2 ) なお、 d 0 Z 2， d 0Z 2 ^ 0である場合には、 s i n ( ά θ / 2 ) ^ d 0 2 ^ t a n ( ά θ / 2 ) , s i n ( ά φ / 2 ) ^ ά φ Z 2 ^ t a n ( d 0 Z 2 ) と近似できるので、 （ 1 1 ) ， （ 1 2 ) 式において s i n ( d θ / 2 ) ， s i n ( d 0 2 ) の代わりに、 d SZ 2 または t a n ( d 2 ) , d 0Z 2 または t a n ( d ø / 2 ) と して も良い。 産業上の利用可能性 -sin (ά φ / 2)-(1 2) If d 0 Z 2 and d 0Z 2 ^ 0, sin (ά θ / 2) ^ d 0 2 ^ tan (ά θ / 2) , sin (ά φ / 2) ^ ά φ Z 2 ^ tan (d 0 Z 2), so that in equations (1 1) and (1 2), sin (d θ / 2) and sin (d 0 2 ) Instead of d SZ 2 or tan (d 2), d 0Z 2 or tan (d ø / 2) Industrial applicability
以上のよ う に、 本発明では、 光学ュニッ トに防塵構造が設けられ ているので、 外部の塵埃が光学ュニッ ト内に入って内部の光学部材 に付着する こ とがなく 、 塵埃付着に伴う光学部材の特性の劣化を防 止でき、 指示物の位置を正確に検出できる。  As described above, in the present invention, since the dust proof structure is provided in the optical unit, external dust does not enter the optical unit and adhere to the internal optical members. Deterioration of the characteristics of the optical member can be prevented, and the position of the indicator can be accurately detected.
また、 光量が最小となる再帰性反射体からの反射光が、 光学的開 口面に略垂直に入射されるよう にしたので、 光量が最小となる反射 光を効率良く受光でき、 検出精度の向上を図れる。  In addition, since the reflected light from the retroreflector that minimizes the amount of light is made to enter the optical aperture almost perpendicularly, the reflected light that minimizes the amount of light can be efficiently received and the detection accuracy can be improved. Can be improved.
また、 光学的開口面の法線を、 走査光の光軸に対して傾斜させた ので、 光学ュニッ 卜から出射された走査光が光学的開口面で正反射 されて光学ュニッ 卜に入射されるこ とを防止でき、 検出精度の向上 を図れる。  Also, since the normal line of the optical aperture is inclined with respect to the optical axis of the scanning light, the scanning light emitted from the optical unit is specularly reflected by the optical aperture and enters the optical unit. This can be prevented, and the detection accuracy can be improved.
また、 走査光の光軸に対する光学的開口面の法線の傾斜角を受光 部の視野角の半分よ り大き く なるよう にしたので、 受光部に視野角 制限を行った場合にも、 その視野角制限に支障を及ぼさない。  In addition, the inclination angle of the normal to the optical aperture surface with respect to the optical axis of the scanning light is set to be larger than half the viewing angle of the light receiving unit. Does not affect viewing angle restriction.

Claims

言青 求 の 範 囲 Scope of demand
1 . 所定領域の外側に設けた光再帰性反射体と、 前記所定領域と 実質的に平行である面内で光を角度走査する光走査部及び該光走査 部による走査光の前記光再帰性反射体での反射光を受光する受光部 を有する複数の光学ュニッ 卜 とを備え、 前記所定領域に指示物で形 成される走査光の遮断位置を走査角度に対応した前記受光部の受光 出力に基づいて検出する光走査型タツチパネルにおいて、 前記光学 ュニッ トは、 その走査光の領域に光学的開口面を有する防塵構造を 備えるこ とを特徴とする光走査型タツチパネル。  1. A light retroreflector provided outside a predetermined area, an optical scanning section that angularly scans light in a plane substantially parallel to the predetermined area, and the light retroreflectivity of scanning light by the light scanning section. A plurality of optical units having a light receiving unit for receiving the light reflected by the reflector, wherein a light receiving output of the light receiving unit corresponding to a scan angle corresponds to a scan light blocking position formed by an indicator in the predetermined area. 2. An optical scanning touch panel according to claim 1, wherein said optical unit has a dust-proof structure having an optical opening surface in an area of the scanning light.
2 . 前記光学的開口面の法線方向が、 前記反射光の光量が最小と なる走査光の方向に実質的に等しい請求項 1記載の光走査型夕ツチ ノ ネル。  2. The light scanning type sunset lens according to claim 1, wherein a normal direction of the optical aperture surface is substantially equal to a direction of the scanning light at which the amount of the reflected light is minimized.
3 . 前記光学的開口面の法線が、 走査光の光軸に対して傾斜して いる請求項 1記載の光走査型タツチパネル。  3. The optical scanning touch panel according to claim 1, wherein a normal line of the optical aperture surface is inclined with respect to an optical axis of the scanning light.
4 . 走査光の光軸に対する前記法線の傾斜角が、 前記受光部の視 野角の半分よ り大きい請求項 3記載の光走査型タッチパネル。  4. The optical scanning touch panel according to claim 3, wherein an inclination angle of the normal to an optical axis of the scanning light is larger than half a viewing angle of the light receiving unit.
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CN102262485A (en) * 2010-05-26 2011-11-30 北京汇冠新技术股份有限公司 Touch positioning method and device, touch screen, touch system and display
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