JPH11327769A - Coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the device which can have high stability and reliability, and a fast detection speed and high detection precision and is simple in structure and low-priced by providing concave surfaces corresponding to photodetectors on the circumferential flank of a flat plate member. SOLUTION: The four corners 100a to 100d of the flat plate member 102 to which a fluorescent dye 101 is uniformly added are formed into the concave surfaces and the photodetectors 103a to 103d are arranged facing the concave surfaces. The photodetectors 103a to 103d are connected to a detecting circuit part 111. Consequently, only lights which travel to the respective photodetectors 103a to 103d as to lights which are transmitted in the flat plate member 102 and reach the concave surfaces of the four corners 100a to 100d are projected on the photodetectors 103a to 103d and other lights are refracted not to the photodetectors 103a to 103d when projected out of the concave surfaces. Consequently, only the light components which should be photodetected originally are photodetected, so the detection precision is increased. Further, light absorbing members 104a to 104d are arranged on the four sides of the flat plate member 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device for detecting the position coordinates of a point designated on a plane and transmitting it to various information devices as pointing information, and more particularly, to projecting a light beam on a plane of a transparent flat plate. The present invention relates to a coordinate input device using an optical method for detecting coordinates from the amount of attenuation of the propagation light inside the flat plate that has sometimes occurred.

[0002]

2. Description of the Related Art Along with the development of information devices, a method of operating a device by instructing a screen of a display device has been widely used. At the same time, the importance of a coordinate input device called a pointing device, which designates a point on a screen and transmits its position coordinate information, has been increasing, and various methods have been proposed. A mouse is the best known form of product. Recently, joysticks have been widely used for games.

[0003] The current situation of the mouse can be known from the commentary described on pages 75 to 79 of the November 1997 issue of Electronics Magazine as a reference.
Most mice are so-called ball mice that operate a rotary encoder using the rotation of a ball incorporated therein. As described on page 77 of the above-mentioned reference, the ball mouse has a problem in that rotation is difficult to be transmitted due to the adhesion of dust and detection errors of position coordinates occur, so that periodic cleaning must be performed. ing. In addition, it is difficult to increase the position coordinate detection accuracy due to slippage in the rotation transmission system.

An optical mouse which realizes a high detection accuracy by reading an orthogonal stripe pattern printed on a mouse pad with a light receiving element is known. As described on page 78 of the above-mentioned reference, an orthogonal mouse is used. It is difficult to design and adjust the device to read the stripe pattern with good contrast, it is susceptible to dirt on the mouse pad surface, and the line width of the stripe pattern and the size of the light receiving window of the light receiving element are reduced. There are limitations,
There is a problem that the resolution cannot be increased.

[0005] The mainstream of the joystick is a system in which the rotation of the operation rod in an arbitrary direction is divided into two directions on a plane, and the respective rotation angles are read by a rotary encoder. As an example, FIG. 1 of Japanese Patent Application Laid-Open No. 9-134646 shows a schematic exploded perspective view of a joystick device. In the figure, the operation members (46 in the figure)
No. 0) fits the spherical portion (463) provided integrally with the through hole (492A), and uses this portion as a fulcrum of the tilting operation. A first interlocking member (the same as in the fourth embodiment) is provided between the flange (462) of the operation member and the space between the flange and the spherical portion.
20) and a groove (431A) provided in the second interlocking member (430).
Then, the tilting operation of the operating member is broken down into rotational operations orthogonal to each other by the two interlocking members. The disassembled two rotation operations are transmitted to two rotary encoders each consisting of a first and a second disk (440 and 450) and a first and a second sensor (470 and 480), respectively. It is possible to obtain coordinate information corresponding to the tilting state of the member.

As typified by the above-mentioned prior application, the joystick device separates the tilting operation of the operating member into two rotating elements through a mechanical element. For this reason, the structure becomes complicated, so that there are problems that it is difficult to reduce the cost, that the coordinate detection accuracy cannot be increased, that the mechanical elements are easily worn or damaged, and that long-term reliability is lacking. In addition, since the rotary encoder handles digitized signals, it is generally difficult to obtain high resolution at a small number of rotations, and it is difficult to increase the resolution of coordinate detection.

A joystick in which the mechanical elements are reduced and the resolution is increased by analog signal detection is disclosed in
This is shown in FIG. 2 of 27605. In the figure, a lever (17 in the figure) is supported by a fulcrum (20) so as to be tiltable, and is connected to a spherical plate (14) around the fulcrum via a connecting member (18). Both the inner and outer surfaces of the spherical plate are reflection surfaces, and the reflectance changes at a constant rate along a certain direction, and the directions of change of the reflectance of the inner and outer surfaces are orthogonal to each other. A light source (10) for irradiating light and a photoelectric element (12) for detecting reflected light are fixedly arranged inside and outside the spherical plate, respectively, facing the reflection surface. When the lever is tilted, the spherical plate also tilts integrally. At this time, a coordinate signal can be obtained by detecting a change in the reflectance on both the inner and outer surfaces as a change in the reflected light intensity with the two photoelectric elements.

In the above conventional example, it is necessary to precisely form the spherical shape of the spherical plate, so that there is a problem that it is not easy to reduce the cost. Further, it has been even more difficult to form a reflecting surface on which the reflectivity changes at a constant rate. For this reason, it has been difficult to practically increase the coordinate detection accuracy despite the fact that analog signals can be detected in a system.

A joystick aiming at realizing higher-precision position detection with a simpler mechanism is disclosed in Japanese Patent Application Laid-Open No. Sho 61-3 / 1986.
FIG. 1 and FIG. 2 of Japanese Patent Publication No. 2131.
This joystick comprises a lever (3) rotatably supported via a ball (2) in the upper center of a casing (1 in the figure), and a light source (5) mounted on the tip of the lever. And a two-dimensional semiconductor position detector (No. 6) disposed above the bottom surface of the casing. The two-dimensional semiconductor position detector has a configuration in which a transparent conductive film, a p-type amorphous silicon layer, an i-type amorphous silicon layer, an n-type amorphous silicon layer, and a transparent conductive layer are sequentially stacked on a substrate. The two-dimensional semiconductor position detector comprises an x-direction electrode (6a, 6b) and a y-direction electrode (6c, 6c).
6d), when a light beam is incident from the light source, the amorphous silicon layer having a three-layer structure is brought into a conductive state, and by measuring current values flowing into the x-direction and y-direction electrodes, The coordinates of the beam incident position can be detected.

In the above conventional example, the two-dimensional semiconductor position detector for detecting the incidence of the light beam has a simple structure in which thin films are stacked in multiple layers, and the mechanism for attaching the operation lever is simple. Its practicality is considered high.
However, in order to receive the light beam moved by the lever operation, it is necessary to increase the area of the two-dimensional semiconductor position detector, and it is not easy to suppress the variation of the detection characteristics and to achieve the uniformity in this large area. Accumulation of a great deal of know-how in film forming process technology development is indispensable, and it must be technology development aiming at cost reduction, and capital investment for development and production will also be large. Clearly, not everyone can easily do it.

Commercially available CCD (Charge Coupled Device)
A joystick that can be easily constructed by anyone using an image sensor is disclosed in Japanese Patent Application Laid-Open No. 61-276014.
It is shown in the figure. In the figure, a lever (11), a lens (13), a two-dimensional CCD sensor (14) are installed on a joystick body (10 in the figure) having a dark box structure, and a light source (12). Are mounted so as to move in conjunction with the movement of the lever. Light from the light source is condensed by the lens and radiated as a light spot on the two-dimensional CCD sensor. The light spot moves on the two-dimensional CCD sensor in conjunction with the movement of the lever. The two-dimensional CCD sensor is scanned in the X and Y directions by a control signal, and outputs an X and Y coordinate signal indicating the position of the light spot by detecting the level of a voltage signal output as a result.

A problem in the above conventional example is that when the tilt angle of the lever is increased, the light source and the two-dimensional CCD
This means that the distance from the sensor surface increases, the light condensing position of the fixed lens shifts, and the light spot on the two-dimensional CCD sensor surface spreads. In combination with this fact and the fact that the area of the two-dimensional CCD sensor is generally not large, in this conventional example, the tilt angle of the lever is limited to a small range, and it is incompatible with the operation feeling by human hands. As a result, it is difficult to increase the control accuracy.

Another problem in the conventional example is that the position coordinates of the light spot cannot be output unless the two-dimensional CCD sensor is scanned and completed in the X and Y directions. This indicates that since the scanning in both the X and Y directions is normally performed at a rate of 60 times per second, the coordinate detection speed of the light pen cannot be more than 60 points per second. That is, when the light pen is moved quickly, there is a problem that only discrete coordinate positions can be detected.

FIG. 1 of Japanese Patent Application Laid-Open No. 58-10275 shows a graphic input device which has a simple structure and is transparent and can be used by being superimposed on various display devices. In this figure, the figure input device includes a flat plate (input plate) having a structure that contains a phosphor that absorbs light and emits fluorescence and has upper and lower surfaces covered with low refractive index layers (1 in the drawing). Light from a light pen (No. 2) that receives a small-diameter beam of light having a wavelength that matches the absorption wavelength of the flat plate (input plate), and the light intensity propagated around the flat plate (input plate) It is detected by the light receiving elements (3a, 3b, 3c, 3d) and the position coordinates of the light pen are output from the output electric signal.

A problem with the above-described graphic input device is that, when the graphic input device is used indoors, external light from a ceiling light or the like is input to the flat plate (input plate), and the phosphor contained in the flat plate (input plate) is removed. Exciting and emitting light. Light emitted almost uniformly in the flat plate (input plate) is the flat plate (input plate).
Therefore, even if the external light is used in an environment where the outside light is weak, the light collected around the flat plate (input plate) has a high intensity. As a result, around the flat plate (input plate), the light from the light pen is buried in the light from the external light, and it becomes difficult to output the position coordinates of the light pen.

Another problem with the above-described graphic input device is that the light propagating to the light receiving element is reflected around the flat plate (input plate) in addition to the light propagating directly from the light incident portion from the light pen. It also includes light. As a result, it is difficult to output a precise coordinate position of the light pen.

Japanese Patent Application Laid-Open No. Hei 4-127313 discloses that an input panel provided with an XY matrix optical waveguide containing a fluorescent substance is irradiated with light by a light-emitting light pen incorporating a light-emitting element, so that the inside of the optical waveguide is exposed. The optical coordinate input device detects the position coordinates of the light emitted by the light emitting pen while the light emitted by the excitation light is directly propagated inside the optical waveguide, and the propagated light is received by the light receiving element arranged at the light emitting end. It has been disclosed.

In the conventional example described above, the X
An input panel having a -Y matrix structure requires precise processing technology and is very expensive at present. Further, it is necessary to form a light receiving element array having light receiving elements corresponding to each of the optical waveguides, and it is difficult to make the element characteristics uniform and it is difficult to reduce the cost of the light receiving element array. Has issues. Furthermore, since a precise assembly technique for realizing precise alignment between each optical waveguide and the light receiving element is required, there are problems that mass productivity is poor and that the price of the device is high.

Japanese Patent Application Laid-Open No. Sho 61-125640 discloses a slit provided in a flat plate made of a material that does not transmit light and disposed at two adjacent corners of a display screen, and radially emits light other than visible light. There is disclosed an input device including a light pen that emits light, and a light receiving sensor group arranged in an arc around the slit so as to receive light transmitted through each slit among the light emitted by the light pen.

In the above-mentioned conventional example, since a large number of light receiving sensors are required to form a light receiving sensor group, and these large number of light receiving sensors must be precisely arranged in an arc shape, etc. In addition, there are difficult problems such as precision assembly for disposing the miniaturized light receiving sensor in an arc shape.

In addition, as a conventional example relating to an optical coordinate input device, Japanese Patent Application Laid-Open No. 61-282912 discloses a direction specifying device using a light pen having a drive power source frequency selecting means. Japanese Patent Application Laid-Open No. 63-155320 discloses a light spot position detecting device in which the light pen is caused to emit light in an alternating manner to eliminate the influence of external light.

[0022]

As described above,
In each prior art, there is no known coordinate input device that achieves high stability and reliability, high detection speed and detection accuracy, and satisfies all the conditions of simple structure and low cost.

More specifically, the ball mouse, which is widely used at present, uses a transmission system based on friction, so that the accuracy of detecting the position coordinates is low, and the position coordinates must be periodically cleaned unless the rotating part is periodically cleaned. There is a problem that detection failure occurs.

The optical mouse requires high sensitivity of the detecting part, so that it is not easy to design and adjust the device, and it is affected by dirt on the surface of the mouse pad, so that it lacks stability and reliability. is there. Further, there is a problem that it is difficult to increase the resolution of coordinate detection.

The rotary encoder type, which is widely used among various joysticks, uses a lot of mechanical elements, so that the structure is complicated, and it is difficult to reduce the cost, improve the detection accuracy, and increase the reliability. There is. Further, it is difficult to increase the resolution of coordinate detection.

In the case of an optical joystick using a spherical concave and convex reflecting surface whose reflectance changes at a constant rate along a certain direction, it is difficult to increase the accuracy of the formation of the reflecting surface. There is a problem that accuracy cannot be increased.

An optical joystick using a two-dimensional semiconductor position detector formed by laminating three types of semiconductor thin films between upper and lower transparent conductive films has not yet reached the stage where the two-dimensional semiconductor position detector is commercially available. However, there is a problem that it takes a lot of investment and time to develop this.

An optical joystick using a commercially available two-dimensional CCD sensor is difficult to use because the tilt angle of the operation lever is limited to a small range and is incompatible with human operation sensation, and it is difficult to increase control accuracy. Also, X,
There is a problem that the coordinate detection speed cannot be increased due to the limitation by the scanning speed in both Y directions.

A graphic input device for inputting light with a light pen to a flat plate (input plate) containing a phosphor, detecting light intensity with a light receiving element arranged around the flat plate (input plate), and outputting a coordinate signal. In this case, there is a problem that it is difficult to detect the position coordinates of the light pen because the light pen is affected by external light such as a ceiling light. Further, there is a problem that it is difficult to accurately detect the coordinate position of the light pen due to the influence of light reflected from a peripheral portion of the flat plate (input plate).

In the optical coordinate input device in which the input panel is constituted by the XY matrix optical waveguide, the characteristics of the light receiving element array are made uniform and the price is reduced, the input panel is reduced in cost, the mass productivity of the device is improved, and the price is reduced. However, there is a problem that both are difficult.

In an input device for obtaining a coordinate position from an angle of light passing through slits provided at two adjacent corners, there is a technical and economical problem of precisely arranging a large number of sensors in an arc shape. I have.

An object of the present invention is to solve the above-mentioned problems of the prior arts and to provide a highly practical coordinate input device.

[0033]

According to the present invention, there is provided a coordinate input device which emits light by the incidence of light and generates a propagating light by the emission of light, and a spot light incident on an upper surface of the flat member. A light source unit including a condensing optical unit, a light emitting unit, and a power supply unit; a plurality of light receivers disposed on a side surface around the flat plate member; and the spot on the flat plate member receiving an output signal of the light receiver. A detection circuit for outputting a signal relating to the position coordinates of light; and a plurality of concave surfaces provided on side surfaces around the flat plate member corresponding to each of the plurality of light receivers.

A coordinate input device according to another aspect of the present invention comprises:
A flat plate member that emits light upon incidence of light and generates internally propagated light by the light emission; and a light source unit including a condensing optical unit, a light emitting unit, and a power supply unit for causing a spot light to be incident on an upper surface of the flat plate member. A plurality of light receivers arranged on a side surface around the flat plate member, and a detection circuit unit that receives an output signal of the light receiver and outputs a signal related to a position coordinate of the spot light on the flat plate member. And a light absorbing member disposed in close contact with a side surface of the flat plate member except for a portion where the concave surface is formed.

According to still another aspect of the present invention, there is provided a coordinate input device comprising: a flat plate member which emits light upon incidence of light and generates internally propagating light by the light emission; and a collecting member for making a spot light incident on the upper surface of the flat plate member. A light source unit including an optical optical unit, a light emitting unit, and a power supply unit; a plurality of light receivers disposed on a side surface around the flat plate member; and the spot light on the flat plate member receiving an output signal of the light receiver. A plurality of concave surfaces provided on the side surface around the flat plate member corresponding to each of the plurality of light receivers, and a plurality of concave surfaces provided around the flat plate member. A light-absorbing member that is disposed in close contact with the side surface except for the portion where the concave surface is formed.

[0036] In this case, the concave surface may have a hollow cylindrical or spherical shape.

Further, the light absorbing member may include an optical member having a refractive index equal to or greater than that of the flat plate member, and a light absorbing medium contained in the optical member.

In any of the above cases, the light source section may be arbitrarily movable.

The light source unit is provided inside a manual operation rod rotatable around a fixed point on a vertical line extending upward substantially through the center of the upper surface of the flat plate member,
The flat plate member is disposed in a housing that blocks external light together with the manual operation rod, and the manual operation rod is formed such that the spot light passes through the fixed point and has a straight line having substantially the same inclination angle as the manual operation rod. It may be arranged so that it is formed in.

Further, a transparent protective layer having a smaller refractive index than the flat plate member is laminated on the upper surface of the flat plate member, and the light source unit is manually moved on the transparent protective layer on the upper surface of the flat plate member. The spot light may be provided inside the mouse so as to emit light from the bottom of the mouse and to enter the spot light on the upper surface of the flat plate member.

(Operation) In the coordinate input device according to the present invention configured as described above, the photodetector is arranged at the portion where the concave surface is formed around the flat member containing the fluorescent dye. Of the light that has reached the concave surface, only the light that goes to each light receiver is emitted toward each light receiver, and the other light is refracted toward other than each light receiver when emitted from the concave surface to the outside. As a result, only the light component that should be received is received, and the detection accuracy can be improved.

Further, by arranging the light absorbing member on the side surface except for the portion where the concave surface around the flat plate member is formed, light propagating inside the flat plate member is prevented from being absorbed and reflected by the side surface. Is done. As a result, the light generated by the emission of the fluorescent dye at the spot light incident portion, only the straight component to the light receiver is detected by the light receiver, and the position coordinates of the spot light incident portion can be detected with higher accuracy. It becomes possible to detect.

Further, the light absorbing member is made of an optical member containing a light absorbing medium, and the refractive index of the optical member is made equal to or larger than that of the transparent flat plate member so that the light can propagate inside the transparent flat plate member. The light passing through the side surface enters the optical member, and is absorbed by the light absorbing medium contained therein.

[0044]

Next, an embodiment of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 is a schematic structural view showing a first embodiment of a coordinate input device according to the present invention. FIG. 1A is a side view, and FIG.
Is a plan view.

As schematically shown in FIG.
01 formed in a state in which No. 01 is uniformly added.
The four corners 100a, 100b, 100c, 100d of the photodetectors 103a, 103a,
3b, 103c and 103d are arranged. Receiver 1
03a, 103b, 103c, and 103d are connected to the detection circuit unit 111, respectively. Thus, of the light that propagates inside the flat plate member 102 and reaches the concave surfaces of the four corners 100a to 100d, only the light that goes to each of the light receivers 103a to 103d is emitted toward each of the light receivers 103a to 103d. Is emitted to the outside from the concave surface, and is refracted to portions other than the light receivers 103a to 103d. As a result, only the light component that should be received is received, and the detection accuracy is improved.

On the four sides of the flat plate member 102, the light absorbing members 10
4a, 104b, 104c and 104d are arranged.

This embodiment is used in combination with a light source unit 105 which is manually moved on the upper surface of the flat plate member 102. As shown in FIG. 1A, the light source unit 105 forms a light emitting unit 106, a power supply unit 107 for causing the light emitting unit 106 to emit light, and forms light from the light emitting unit 106 into a spot shape. And condensing optical means 108 for outputting the light.

The power supply means 107 includes a frequency selection means 109
And a driving circuit unit 110 connected to the frequency selecting unit, and the light emitting unit 106 emits light at a frequency selected by the frequency selecting unit 109 from a plurality of predetermined frequencies.

The frequency selecting means 109 can be constituted by using various well-known oscillation circuits. For example, as shown in FIG. 2, when using the oscillation circuit means 112 that can change the oscillation frequency by changing the capacitance,
Three different capacitors 113a, 113b having capacitances corresponding to three predetermined oscillation frequencies,
The frequency can be selected by switching 113c with two selection switches 114a and 114b.

It is optimal to use a light emitting diode or a laser diode as the light emitting means 106. At this time, the driving circuit means 110 outputs the pulse current intermittently at the frequency selected by the frequency selecting means 109 to the light emitting means 10.
6 is constituted by a circuit for conducting.

As shown in FIG. 3, the detection circuit section 111 has a filter circuit means 115, a signal processing circuit means 116 and an addition circuit section 122. The filter circuit means 115 includes a band-pass filter circuit 117.
a, 117b, 117c, 117d, 118 and 11
9, the signal processing circuit means 116 comprises a coordinate position calculation circuit 116, select processing circuits 121a and 121b, and the addition circuit section 122 comprises each of the photodetectors 103a to 103a.
Add the 03d output.

The light receivers 103a, 103b, 103c, 1
The detection signal from 03d is an AC signal having a predetermined frequency. In this embodiment, the predetermined frequency is defined as f ₁ ,
Description will be given as three types represented by f ₂ and f ₃ . Bandpass filter circuit 117 constituting filter circuit means 115
a~117d is provided for the frequency f _1, each of the band-pass filter circuit 118 and 119 are provided respectively frequency, with respect to f _2, f _3. When a signal detected by each of the photodetectors 103a to 103d is input, the signal is output after passing through a band-pass filter circuit for any one of three types of frequencies.

In this embodiment, the signal having the frequency f ₁ is input to the coordinate position calculation circuit 120 of the signal processing circuit means 116, and as a result, the position coordinate signals V (x) and V (y) are output. Signal frequency is f ₂ and f ₃ are respectively inputted to the select processing circuits 121a and 121b of the signal processing circuit unit 116, as a result two select signals V _S1, V _S2 are output. In order to output a select signal, a detection signal from any one of the light receivers may be used. In this embodiment, a signal obtained by adding detection signals from all the light receivers by the addition circuit unit 122 is used. This stabilizes the operation. In this embodiment, an example in which two types of select signals are output has been described. However, by setting a required number of types of signal frequencies, it is possible to output a required number of select signals.

The principle of operation in this embodiment will be described with reference to FIGS. The spot light emitted from the light source unit 105 shown in FIG. 1 is incident on the inside of the flat plate member 102 as the incident light 123 in FIG. The fluorescent dye 101 added to the inside of the flat plate member 102 emits light when excited by incident light, and at this time, the light is emitted isotropically. As shown in FIG. 4, the emission direction 124 of light emitted inside the flat plate member 102 is represented by an angle θ taken from a direction perpendicular to the upper and lower surfaces of the flat plate member 102, and the critical angle 1
Assuming that 25 is θ _c , the light emitted in the range of θ _c <θ <180 ° −θ _c is indicated by a dotted line in FIG.
As indicated by reference numeral 26, the light is totally reflected on the upper and lower surfaces of the flat plate member 102 and does not go out of the flat plate member 102. The propagating light 126 is gradually absorbed by the plate member 102 itself and the dispersed fluorescent dye 101 in the process of propagating inside the plate member 102, and the light intensity decreases as the propagation distance increases. That is, the propagation distance and the light intensity are in inverse proportion. Therefore, as shown in FIG. 5, the position where the fluorescent dye is excited and emits light in the flat plate member 102 having the horizontal and vertical lengths of a and b, respectively, is represented by coordinates (x, y). 103a, 103b, 103c, 1
The distance to 03d and _{r 1, r 2, r 3} , r 4 , respectively,
The light intensity of the propagating light detected by each light receiver is represented by I ₁ ,
Assuming that I ₂ , I ₃ , and I ₄ , k is a proportional constant, and r ₁ = k / I ₁ , r ₂ = k / I ₂ , r ₃ = k / I ₃ , and r ₄ = k / I ₄ . Have a relationship. However, this relationship holds because, of the light emitted at the coordinate position (x, y), the light that has propagated to the four sides of the flat plate member 102 is the light absorbing member 104 shown in FIG.
a, 104b, 104c, and 104d, and is limited to the case where the light is not reflected inside the flat plate member 102. That is, by detecting only light that has propagated straight from the light emitting position in the flat plate member 102 to the light receiving device, it is possible to accurately measure the distance between the light receiving device and the light emitting position. ^{Furthermore, x 2 + y 2 = r} 1 2 x 2 + (b-y) 2 = r 2 2 (a-x) 2 + (b-y) 2 = r 3 2 becomes relevant. From these relational expressions, the position coordinates (x,
y) is obtained as follows.

[0056] ^{_{x = K X (I 3 2}} -I 2 2) / (I 3 2 I 2 2) + a / 2 y = K Y (I 2 2 -I 1 2) / (I 2 2 I 1 2) + B / 2 where K _X and K _Y represent proportional constants. As is apparent from the above relational expression, generally, the position coordinate x is equal to two light receivers (one of 103a or 103b and 103
c or 103d). Similarly, the position coordinate y is obtained from output signals of two light receivers arranged in the vertical direction. First, the coordinate position calculation circuit 120 shown in FIG. 3 receives the signal from the light receiver according to the above relational expression and outputs the position coordinates (x, y), and uses a normal circuit design technique. It can be easily configured. As an example, FIG. 6 shows a circuit example configured using an analog multiplier and an analog operational amplifier.

The circuit shown in FIG.
01 _{1-601 4} and 5 of the analog operational amplifiers 602 ₁ -
And a 602 _5. Analog multiplier 601 _1,
601 ₄ of each light receiver 103b for each input, the input light intensity I _2, I ₃ of the propagation light detected at 103c, each of these outputs are inputted to the analog multiplier 601 ₂ and the analog operational amplifier 602 ₁ ing. Analog multiplier 601 ₂
The output of the input to the analog multiplier 601 _3, output of the analog operational amplifier 602 ₁ analog operational amplifier 602 ₂
Is input on the negative side of. Analog operational amplifier 602 ₂
Of the analog multiplier 60 is grounded and its output is
Is input to the positive side of the analog operational amplifier 602 ₄ is inputted to the 1 _3. Feedback resistor for determining the amplification factor is provided between the output and the analog operational amplifier 602 ₄ of the negative-side input. Analog operation amplifier 602 outputs an analog operational amplifier 602 ₄ together with the output of the analog operational amplifier 602 ₃ for generating an offset voltage a / 2 ₅
Is input to the negative side, the positive side input analog operational amplifier 602 ₅ is grounded.

The output of the main part of each circuit in FIG. 6 is as follows.

[0059] Analog multiplier 601 ₁ output = I ₂ ² analog multiplier 601 ₂ output = I ₃ ² I ₂ ² analog multiplier 601 ₃ output = I ₃ ² -I ₂ ² analog multiplier 601 ₄ output = I ₃ ² Analog operational amplifier 602 ₁ output = I ₃ ² −I ₂ ² Analog operational amplifier 602 ₂ output = (I ₃ ² −I ₂ ² ) / I ₃
² I ₂ ² Analog operational amplifier 602 ₃ output = a / 2 Analog operational amplifier 602 ₄ output = K _X (I ₃ ² −I ₂ ² ) /
I _{3 ²} I ^{2 2} analog operation amplifiers 602 ₅ Output ^{_{= K X (I 3 2 -I}} 2 2) /
I ₃ ² I ₂ ² + a / 2 The input in the circuit example shown in FIG. 6 is a signal from two light receivers that passed through the filter circuit means 115 in FIG. 3, and the output is x of the position coordinate. Can output y coordinates by selecting a feedback resistance value of the analog operational amplifier 602 _4, the coordinate position calculating circuit 120 may be constructed by aligning two sets of the circuit of FIG.

As the transparent member for forming the flat plate member 102, glass or plastic material can be used. Especially,
Plastic optical materials such as polymethyl methacryl, polycarbonate, and polystyrene can be optimally used because they can be molded in a low temperature range where the fluorescent dye to be added does not decompose. Many commercially available fluorescent dyes are known, and these can be used. Examples of suitable commercial products include fluorescent dyes sold under the trade name Lumogen F by BASF Japan Ltd. If this fluorescent dye is added, for example, at a rate of 0.02% to polymethyl methacrylic resin, a flat plate member suitable for the coordinate input device according to the present embodiment can be formed.

The light absorbing members 104a to 104d arranged on the side surfaces of the flat plate member 102 are formed by using a transparent member similar to the flat plate member 102 and uniformly dispersing a light absorbing agent such as carbon black in the transparent member. Is done. Of the three types of plastic optical materials described above, polymethyl methacrylic resin has the smallest refractive index. Therefore, when the flat member is formed of polymethyl methacrylic resin as in this embodiment, the light absorbing member The transparent member used in (1) may be any of the three types of plastic optical materials. As an example, a light-absorbing member in which carbon black was uniformly dispersed by 5% in polymethyl methacrylic resin was formed. Since this light absorbing member uses the same transparent member as the flat plate member shown in the embodiment, it can be easily bonded to the side surface of the flat plate member.

As a result of using the flat plate member and the light absorbing member shown in this embodiment in the coordinate input device according to the present invention, the operation principle according to the present invention was confirmed, and the stability, reliability, detection speed,
It was confirmed that the problems related to the practicality of the conventional technology in terms of detection accuracy, cost, and the like can be solved.

Second Embodiment FIG. 7 is a schematic diagram showing the configuration of a coordinate input device according to a second embodiment of the present invention. In the coordinate input device according to the present embodiment, the light source unit is disposed inside the manual operation rod 130, and the coordinate position is designated by tilting the operation rod by hand. Many of the components in the present embodiment are shown in FIG.
Are the same as those in the first embodiment shown in FIG. 1, and therefore, are denoted by the same reference numerals as in FIG. 1 and description thereof is omitted.

In FIG. 7, a spherical convex surface 131 is provided at the center of rotation of the manual operation rod 130, and is fitted into a spherical concave through hole 133 provided at the center of the support plate 132 to be pivotally supported. As a result, the manual operation rod 130 can rotate around the center 134 of the spherical convex surface 131. The center 134 is configured to be on a vertical line 135 passing through substantially the center of the flat plate member 102 that emits light upon incidence of light and propagates light therein.

A support plate 132 to which the manual operation stick 130 is attached is supported by a housing 136. Housing 136
Is shielded from external light. For this reason, in this embodiment, there is no need to consider the influence of external light at all, and stable operation can always be performed. Inside the manual operation rod 130, a light emitting means 106, a power supply means 107 having a frequency selecting means 109 for driving the light emitting means and a driving circuit means 110, and a condensing optical means 108 are incorporated.
The light emitted by the light emitting means 106 and the light collected by the light collecting optical means 108 exit on a straight line 137 passing through the center 134 and enter the flat plate member 102 as spot light. As a result,
By changing the inclination of the manual operation rod 130, the spot light incident position on the flat plate member 102 changes.

The means and method for detecting the coordinates of the spot light incident position in this embodiment are exactly the same as those described in the first embodiment. Basically, it is obtained by detecting the light intensity attenuating in inverse proportion to the distance by the photodetectors 103a to 103d arranged at the four corners of the flat plate member 120, and processing the output signal. That is, according to the present embodiment, the rotation of the manual operation rod 130 about the center 134 corresponds one-to-one with the coordinates of the spot light incident position of the flat plate member 102. Therefore, the coordinate input device according to the present embodiment can be used as a so-called joystick. When this embodiment is used as a joystick, there are almost no mechanical elements, the structure is simple, the cost is reduced,
High accuracy, high reliability, and high resolution have become possible.

Third Embodiment FIG. 8 is a schematic diagram showing a coordinate input device according to a third embodiment of the present invention. In the coordinate input device according to the present embodiment, a light source unit is arranged inside a manually operated mouse, and a coordinate position is designated by moving the mouse manually. Many of the components in the present embodiment are shown in FIG.
Are the same as those in the first embodiment shown in FIG. 1, and therefore, are denoted by the same reference numerals as in FIG. 1 and description thereof is omitted.

In FIG. 8, a light-transmitting surface protective layer 138 is shown.
A mouse 139 that can be moved manually is placed on the surface of the flat plate member 102 covered with. The surface protective layer 138 is provided to prevent the surface of the flat plate member 102 from being damaged when the mouse 139 is moved. Inside the mouse 139, a light emitting means 106, a frequency selecting means 109 and a driving circuit means 11 for causing the light emitting means 106 to emit light are provided.
0, and a condensing optical unit 108, and a right-angle prism 140 for causing the light condensed by the condensing optical unit 108 to enter the surface of the flat plate member 102 at right angles. It is arranged before the optical optical means 108.

The light incident on the flat plate member 102 excites the fluorescent dye 101 added inside the flat plate member to generate light. The light emitted from the fluorescent dye propagates inside the flat plate member, and the light intensity decreases with the propagation distance. Flat plate member 1
The position coordinates of the incident spot light can be obtained by detecting the intensities of the light propagated to the four corners by the photodetectors 103a to 103d arranged at the four corners of 02. These spot light incident position coordinate detecting means and method are exactly the same as those described in the first embodiment. Basically, since the intensity of light propagating inside the flat plate member 102 attenuates in inverse proportion to the propagation distance, the light receivers 103a to 103a-1
The position coordinates are obtained by performing arithmetic processing on the output signal 03d in accordance with the relational expression described in the first embodiment.

In order not to hinder the incidence of light from the light source unit and not to affect the propagation light inside the flat plate member, the surface protective layer 135 has a good light transmittance and a flat refractive index. It is necessary that the refractive index be smaller than the refractive index of the member 102. Since the light from the light source unit is always incident orthogonally on the surface of the flat plate member 102, the incident spot light is always in a narrowed state, and precise position coordinate detection is possible.

In order to handle the amount of signal that changes in an analog manner, it is important to keep the noise level of the detection circuit low. However, in this embodiment, since the light source section is structured to be covered by the mouse housing. Incident spot light is flat plate member 1
Since external light does not enter the vicinity of the position where the light beam 02 enters, the noise level of the detection circuit can be easily suppressed low, and the resolution of position coordinate detection can be increased.

Further, since the position coordinates obtained by treating the analog quantity are the center values obtained corresponding to the intensity distribution of the incident spot light, the position coordinates obtained when the surface of the surface protection layer 135 is damaged However, a large detection error rarely occurs. Further, since the flat plate member corresponding to the mouse pad has a simple structure, the cost can be easily reduced.

[0073]

As described above, according to the present invention, the following effects can be obtained in the coordinate input device.

High detection accuracy using the method of calculating the distance from the amount of light attenuation was realized. Compared to a conventional device that uses many mechanical elements, higher detection accuracy and reliability were obtained, and the price was lower.

By handling analog quantities, high resolution and high-speed detection can be realized. In addition, it is hardly affected by optical dirt or the propagation direction of the propagating light. And highly accurate detection has become possible.

The adoption of a method for removing the influence of external light enables highly accurate coordinate input even in a bright place. Further, by preventing unnecessary reflection of the propagation light inside the flat plate member, the accuracy of coordinate detection can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a coordinate input device according to the present invention, (a) is a side view,
(B) shows a plan view.

FIG. 2 is a schematic configuration diagram of a light source unit showing one embodiment of a frequency selection unit.

FIG. 3 is a schematic configuration diagram illustrating an embodiment of a detection circuit unit.

FIG. 4 is a schematic view for explaining the principle of light propagation inside the flat plate member.

FIG. 5 is a schematic diagram for explaining the principle of position coordinate detection.

FIG. 6 is a schematic configuration diagram illustrating an embodiment of a coordinate position calculation circuit.

FIG. 7 is a schematic configuration diagram showing a second embodiment of the coordinate input device according to the present invention.

FIG. 8 is a schematic configuration diagram showing a third embodiment of the coordinate input device according to the present invention.

[Explanation of symbols]

100a, 100b, 100c, 100d Concave surface 101 Fluorescent dye 102 Flat plate member 103a, 103b, 103c, 103d Light receiver 104a, 104b, 104c, 104d Light absorbing member 105 Light source unit 106 Light emitting means 107 Power supply means 108 Light collecting optical means 109 Frequency selection Means 110 Drive circuit means 111 Detection circuit section 112 Oscillation circuit means 113a, 113b, 113c Capacitors 114a, 114b Selection switch 115 Filter circuit means 116 Signal processing circuit means 117a, 117b, 117c, 117d Frequency f
Filter circuit means for ₁ 118 Filter circuit means for frequency f ₂ 119 Filter circuit means for frequency f ₃ 120 Coordinate position calculation circuit 121 a, 121 b Select processing circuit 122 Addition circuit section 123 Optical path 124 Light emission direction 125 Critical angle 126 Propagated light 130 Manual operation stick 131 Spherical convex surface 132 Support plate 133 Through hole 134 Center of spherical convex surface 135 Vertical line 136 Housing 137 Straight line 138 Surface protective layer 139 Mouse 140 Right angle prism

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 31/16 H01L 31/16 B

Claims (8)

[Claims] 1. A flat plate member which emits light upon incidence of light and generates internally propagating light by the emitted light; a condensing optical unit, a light emitting unit, and a power supply unit for causing a spot light to be incident on an upper surface of the flat plate member. A light source unit, a plurality of light receivers arranged on side surfaces around the flat plate member, and a detection circuit that receives an output signal of the light receiver and outputs a signal related to a position coordinate of the spot light on the flat plate member. A coordinate input device, comprising: a plurality of light receiving devices; and a plurality of concave surfaces provided on side surfaces around the flat plate member corresponding to each of the plurality of light receivers. 2. A flat plate member which emits light upon incidence of light and generates internally propagating light by the emitted light; a condensing optical unit, a light emitting unit, and a power supply unit for causing a spot light to be incident on an upper surface of the flat plate member. A light source unit, a plurality of light receivers arranged on side surfaces around the flat plate member, and a detection circuit that receives an output signal of the light receiver and outputs a signal related to a position coordinate of the spot light on the flat plate member. And a light absorbing member that is disposed in close contact with a side surface of the flat plate member except for a portion where the concave surface is formed. 3. A flat plate member which emits light by the incidence of light and generates internally propagating light by the light emission; a condensing optical unit, a light emitting unit, and a power supply unit for making a spot light incident on an upper surface of the flat plate member. A light source unit, a plurality of light receivers arranged on side surfaces around the flat plate member, and a detection circuit that receives an output signal of the light receiver and outputs a signal related to a position coordinate of the spot light on the flat plate member. And a plurality of concave surfaces provided on the peripheral side surface of the flat plate member corresponding to each of the plurality of light receivers; and And a light absorbing member arranged. 4. The coordinate input device according to claim 1, wherein said concave surface has a shape of a hollow cylindrical surface or a spherical surface. 5. The coordinate input device according to claim 1, wherein the light absorbing member has an optical member having a refractive index equal to or larger than that of the flat plate member, and the light absorbing member includes the optical member. A coordinate input device, comprising: a light absorbing medium; 6. The coordinate input device according to claim 1, wherein the light source unit is arbitrarily movable. 7. The coordinate input device according to claim 1, wherein the light source unit rotates about a fixed point on a vertical line extending upward substantially through a center of an upper surface of the flat plate member. The flat member is provided inside a housing that blocks external light together with the manual operation rod, and the manual operation rod is arranged such that the spot light passes through the fixed point. A coordinate input device arranged to be formed on a straight line having substantially the same inclination angle as a manual operation rod. 8. The coordinate input device according to claim 1, wherein a transparent protective layer having a refractive index smaller than that of the flat plate member is laminated on an upper surface of the flat plate member, and the light source unit is provided with a transparent protective layer. It is provided inside a mouse that moves manually on the transparent protective layer on the upper surface of the flat plate member, emits light from the bottom of the mouse, and is arranged so that the spot light is incident on the upper surface of the flat plate member. A coordinate input device.