JP2006065595A - Input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an input device allowed to be miniaturized and hardly damaged and capable of reducing power consumption. <P>SOLUTION: The input device is provided with: a light emitting element 3 for emitting light; a light emission driving circuit 4 for driving the light emitting element ; a collimator lens 5 for making light parallel; first and second liquid crystal lenses 6, 7 for changing a focal position to a light traveling direction and a direction vertical to the light traveling direction; a liquid crystal lens control part 8 for controlling the first and second liquid crystal lenses 6, 7; a light receiving element 11 for receiving light reflected by an indicator 1 and returned; a half mirror 9 for reflecting light to the light receiving element 11; a diaphragm part 10 arranged on the light incidence side of the light receiving element 11; an amplifier 12 for amplifying a signal from the light receiving element 11; and a position detection part 13 for detecting the position of an indicator 1 from the control state of the liquid crystal lens control part 8 and a signal from the amplifier. Consequently a focal position can be freely controlled without having a movable part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an input device, and more particularly to an optical scanning type input device that detects the position of an indicator by scanning light with respect to an input region.

  2. Description of the Related Art Conventionally, devices that perform input using an indicator on a display screen, such as computers and information terminals, are widely known. Of these, resistive film type input devices are widely used.

  The resistance film type input device has a problem in that the display quality is deteriorated because the light transmittance decreases due to the structure in which the touch panel composed of two transparent resistance films is arranged on the display device. there were.

  In order to solve this problem, an input device that detects an input by scanning light with respect to the input area is known, and many proposals are being seen (for example, see Patent Document 1).

A conventional input device disclosed in Patent Document 1 will be described with reference to the drawings.
FIG. 7 is a block diagram showing a conventional input device disclosed in Patent Document 1. In FIG. FIG. 8 is a block diagram showing an optical transmission / reception unit of the input device of the prior art shown in Patent Document 1.

In FIG. 7, 80 is a display screen, 50 is a light transmission / reception unit, 51 is a retroreflective sheet that reflects light in the incident direction, 52 is a light reception signal detection circuit, 53 is a light emitting element drive circuit, 54 is an MPU, and 55 is a polygon. In FIG. 8, 58 is a light emitting element composed of a laser diode that emits an infrared laser, 59 is a collimating lens that collimates light, and 60 is a display circuit. A polygon mirror, 62 is a half mirror, 63 is a light receiving element, and 64 is a visible light cut filter.

  The input device of the prior art shown in Patent Document 1 specifies the position of the indicator 57 by detecting that the scanned light is blocked by the indicator 57.

The procedure for detecting the indicator 57 will be described with reference to FIG. The MPU 54 scans light on the display screen 80 from the light transmitting / receiving unit 50 by driving the light emitting element driving circuit 53. When there is no indicator 57 on the light path, the light reaches the retroreflective sheet 51. Since the retroreflective sheet 51 reflects light in the incident direction, the light returns to the light transmission / reception unit 50. When the indicator 57 is on the light path, the light is blocked by the indicator 57 and does not return to the light transmitting / receiving unit 50.
In this way, the light reception signal detection circuit 52 detects whether or not the light returns to the light transmission / reception unit 50, and determines whether or not the indicator 57 is present in the light scanning direction at that time. As shown in FIG. 7, the position of the indicator 57 can be specified by providing two light transmission / reception units 50 at the end of the display screen 80.

The operation of the optical transmission / reception unit 50 will be described with reference to FIG. Light emitted from the light emitting element 58 is converted into parallel light by the collimator lens 59. In the half mirror 62, the light passes as it is, is reflected by the polygon mirror 60, and travels toward the retroreflective sheet 51. When there is no indicator 57, the light returns from the retroreflective sheet 51, is reflected again by the polygon mirror 60, is reflected by the half mirror 62, passes through the visible light cut filter 64, and reaches the light receiving element 63. The polygon control circuit 55 changes the light scanning direction by rotating the polygon mirror 60 with a motor or the like (not shown). In this way, the light transmission / reception unit 50 realizes scanning of light on the display screen 80.

  Moreover, although it is not an input device, the displacement measuring device which measures the thickness of to-be-measured objects, such as a thin film, using light is known (for example, refer patent document 2).

The conventional displacement measuring apparatus shown in Patent Document 2 irradiates light and detects the reflected light from the object to be measured, thereby measuring the thickness of the object to be measured. This is because the reflected light detected is maximized when the irradiated light is focused on the object to be measured, and the reflected light detected when the irradiated light is not focused on the object to be measured. It uses the principle that light is extremely low.
The prior art displacement measuring apparatus shown in Patent Document 2 measures the thickness of a measured object in order to detect reflected light while changing the focus position in the thickness direction of the measured object using a liquid crystal lens. can do.

  A liquid crystal lens has a structure in which a transparent substrate on which a transparent electrode is formed is opposed to each other and a liquid crystal is filled between them, and utilizes the phenomenon that the refractive index of light changes depending on the voltage applied between the transparent electrodes. , Which has worked as a lens.

Japanese Unexamined Patent Publication No. 2004-199714 (page 4-9, FIG. 1-2) JP 2003-97911 A (page 2-5)

  However, the input device of the prior art disclosed in Patent Document 1 has a drawback that it is necessary to provide a plurality of optical transmission / reception units 50 and cannot be reduced in size. Further, since the polygon mirror 60 which is a movable part is provided, there is a disadvantage that it is mechanically fragile. Further, since the polygon mirror 60 is rotated, there is a disadvantage that power consumption is large.

  Further, the conventional displacement measuring apparatus shown in Patent Document 2 measures the thickness of an object to be measured, and does not detect a two-dimensional position like an input device.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an input device that can be miniaturized, is not easily broken, and consumes less power.

  In order to achieve the above object, the input device of the present invention adopts the following structure.

In an optical scanning type input device that detects the position of an indicator by scanning light with respect to an input area,
A light emitting element that emits light, a light emission drive circuit that drives the light emitting element, a collimating lens that collimates the light, a first liquid crystal lens that changes a focal position in the light traveling direction, and the light traveling direction; A second liquid crystal lens that changes the position of the focus in the vertical direction, a liquid crystal lens control unit that controls the first liquid crystal lens and the second liquid crystal lens, and light that is reflected back to the indicator and receives light A light receiving element, a half mirror that reflects light toward the light receiving element, an optical diaphragm provided on the light incident side of the light receiving element, an amplifier that amplifies the signal of the light receiving element, and a liquid crystal lens control unit And a position detector for detecting the position of the indicator from the control state and the signal of the amplifier.

  The first liquid crystal lens has a plurality of concentric transparent electrodes.

  The second liquid crystal lens has a plurality of linear transparent electrodes arranged in parallel.

  According to the input device of the present invention, the provision of the first liquid crystal lens and the second liquid crystal lens eliminates the need for a movable part such as a polygon mirror, makes it difficult to break, and reduces power consumption. The focus can be freely controlled by the first liquid crystal lens and the second liquid crystal lens. Thereby, a highly accurate input device using reflected light from the focal point can be realized.

Since the focus can be freely controlled, the input device of the present invention can be operated only by being attached to the edge of the input region. For this reason, it can be remarkably downsized.
Moreover, since the focus can be freely controlled, it can be applied to various input devices having different input areas, and can be applied as it is without changing hardware. For this reason, the cost as an input device can be remarkably reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a first configuration diagram of an input device according to the present invention, and shows a state in which an indicator is in focus. FIG. 2 is a second block diagram of the input device of the present invention, and shows a state where the indicator is not focused. 3A and 3B are diagrams showing an example of how the input device of the present invention is used, in which FIG. 3A is a front view and FIG. 3B is a side view. FIG. 4 is a cross-sectional view of the liquid crystal lens of the input device of the present invention. FIG. 5 is a transparent electrode pattern diagram of the liquid crystal lens of the input device of the present invention, FIG. 5 (a) is a concentric transparent electrode pattern diagram, and FIG. 5 (b) is a linear transparent electrode pattern diagram. It is. 6A and 6B are diagrams showing an optical aperture section of the input device according to the present invention. FIG. 6A is a diagram in which light is concentrated at the center, and FIG. 6B is a diagram in which light is spread. is there.

[Structure explanation: FIGS. 1 to 6]
First, the configuration of the input device of the present invention will be described with reference to FIGS.
In FIG. 1, 1 is an indicator such as a finger or a pen, 2 is a light transmission / reception unit, 3 is a light emitting element made up of a laser diode or an infrared light emitting LED (Light Emitting Diode), 4 is a light emission drive circuit, and 5 is a parallel light. A collimating lens, 6 is a first liquid crystal lens, 7 is a second liquid crystal lens, 8 is a liquid crystal lens control unit, 9 is a half mirror, 10 is an optical aperture unit, and 11 is a light receiving element comprising a photodiode or phototransistor. , 12 are amplifiers, 13 is a position detector, and 20 is a pinhole which is a minute hole.

  In FIG. 3, 14 is an electronic device, 15 is an input area, and 16 is a focus scanning locus.

  In FIG. 4, 17 is a transparent substrate, 18 is a transparent electrode, and 19 is a liquid crystal. Moreover, the arrow in FIG. 4 has shown the direction of incidence | injection and emission of light.

  In FIG. 6, reference numeral 21 denotes a light irradiation region. 1 to 6, the same number is assigned to the same configuration.

[Principle explanation: Fig.1, Fig.2, Fig.6]
First, the basic principle of detection of the input device of the present invention will be described with reference to FIGS. 1, 2, and 6. FIG.
As shown in FIG. 1, the light emitted from the light emitting element 3 by the light emission driving circuit 4 passes through the half mirror 9 as it is and is converted into parallel light by the collimating lens 5, and then the second liquid crystal lens 7 and the second liquid crystal lens 7. The liquid crystal lens 6 is refracted and focused.
When the indicator 1 is located at the focal point, the light reflected at one point on the indicator 1 returns to the half mirror 9, where it is reflected and gathers again at one point on the optical diaphragm 10, and all the light is pinhole 20. And reaches the light receiving element 11. FIG. 6A shows a state on the optical aperture section 10 at this time.
As shown in FIG. 2, when the indicator 1 is not located at the focal point, the light that has spread and reflected over a wide area on the indicator 1 is reflected by the half mirror 9 and again on the light aperture section 10. Occupy. That is, a very small amount of light passes through the pinhole 20 and reaches the light receiving element 11. FIG. 6B shows a state on the optical aperture section 10 at this time.
The liquid crystal lens control unit 8 drives the first liquid crystal lens 6 and the second liquid crystal lens 7 to scan the focal position two-dimensionally, and the position detection unit 13 peaks the light reception signal amplified by the amplifier 12. It is possible to detect the time when the camera is greeted and detect that the position of the focus at that time is the position of the indicator 1.

[Principle explanation of liquid crystal lens: Fig.4, Fig.5]
Next, the liquid crystal lens of the input device of the present invention will be described with reference to FIGS.
As shown in FIG. 4, the liquid crystal lens has a structure in which a transparent substrate 17 on which a transparent electrode 18 is formed is opposed and a liquid crystal 19 is filled therebetween. When a voltage is applied between the transparent electrodes 18, the direction of the molecules in the liquid crystal 19 changes, thereby changing the refractive index of light. The refractive index depends on the voltage between the transparent electrodes 18. That is, when a high voltage is applied, the refractive index is high, and when a low voltage is applied, the refractive index is low.

As shown in FIG. 5 (a), the transparent electrode 18 is formed concentrically, and the outer transparent electrode 18 is driven at a high voltage, and is driven at a low voltage toward the inner transparent electrode 18. It can be operated as a convex lens, and the focal length can be changed by changing the change rate of the drive voltage. The first liquid crystal lens 6 is a liquid crystal lens having concentric transparent electrodes 18 as shown in FIG.
As shown in FIG. 5B, the transparent electrode 18 is formed in a straight line, and the transparent electrode 18 at one end is driven by driving at a high voltage, and is driven at a lower voltage toward the transparent electrode 18 at the other end. By rubbing, light can be refracted to the left and right. The second liquid crystal lens 7 is a liquid crystal lens having a linear transparent electrode 18 as shown in FIG.

[Description of operation: Fig. 3]
Next, a usage example of the input device of the present invention will be described with reference to FIG.
As shown in FIG. 3, the optical transmission / reception unit 2 provided at the end of the input area 15 of the electronic device 14 is focused on the first liquid crystal lens 6 and the second liquid crystal lens 7 in FIG. It scans two-dimensionally as shown in the focus scanning locus 16 shown. Thereby, the position of the indicator 1 is detected.

  If it is desired to specify the position of the three-dimensional indicator 1, a liquid crystal lens having a linear transparent electrode 18 as shown in FIG. 5B is overlapped so as to be orthogonal to the second liquid crystal lens 7. It can be easily expanded by arranging.

  The input device according to the present invention includes not only the first liquid crystal lens that changes the focal position in the light traveling direction, but also the second liquid crystal lens that changes the focal position in a direction perpendicular to the light traveling direction. As a result, the focal point can be freely controlled two-dimensionally and applied to an input device. In addition, a movable part such as a polygon mirror of an input device according to the prior art is not required, it is difficult to break, and power consumption can be reduced. Further, since the focal point can be freely controlled two-dimensionally, the input device of the present invention can be operated only by being attached to the edge of the input region. For this reason, it can be remarkably downsized.

  The input device of the present invention can be applied to computers, information terminals and the like that are required to be difficult to break and have low power consumption. In particular, it is suitable for portable information terminals that are required to be downsized for reasons such as carrying around.

It is a 1st block diagram of the input device of this invention. It is a 2nd block diagram of the input device of this invention. It is a figure which shows the usage type example of the input device of this invention. It is sectional drawing of the liquid crystal lens of the input device of this invention. It is a transparent electrode pattern figure of the liquid crystal lens of the input device of the present invention. It is a figure which shows the optical aperture part of the input device of this invention. It is a block diagram which shows the input device of a prior art. It is a block diagram which shows the optical transmission / reception unit of the input device of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Indicator 2 Light transmission / reception unit 3 Light emitting element 4 Light emission drive circuit 5 Collimating lens 6 1st liquid crystal lens 7 2nd liquid crystal lens 8 Liquid crystal lens control part 9 Half mirror 10 Optical aperture part 11 Light receiving element 12 Amplifier 13 Position detection part DESCRIPTION OF SYMBOLS 14 Electronic device 15 Input area 16 Focus scanning locus 17 Transparent substrate 18 Transparent electrode 19 Liquid crystal 20 Pinhole 21 Light irradiation area 50 Light transmission / reception unit 51 Retroreflection sheet 52 Light reception signal detection circuit 53 Light emitting element drive circuit 54 MPU
55 Polygon control circuit 56 Display device 57 Indicator 58 Light emitting element 59 Collimator lens 60 Polygon mirror 62 Half mirror 63 Light receiving element 64 Visible light cut filter 80 Display screen

Claims (3)

In an optical scanning type input device that detects the position of an indicator by scanning light with respect to an input area,
A light-emitting element that emits light, a light-emitting drive circuit that drives the light-emitting element, a collimator lens that collimates the light from the light-emitting element, and a first liquid crystal lens that changes a focal position in the traveling direction of the light A second liquid crystal lens that changes a focus position in a direction perpendicular to the light traveling direction, a liquid crystal lens control unit that controls the first liquid crystal lens and the second liquid crystal lens, and the indicator A light receiving element that receives the reflected light, a half mirror that reflects the light toward the light receiving element, an optical aperture provided on the light incident side of the light receiving element, and an amplifying signal of the light receiving element An input device comprising: an amplifier for detecting a position of the indicator from a control state of the liquid crystal lens control unit and a signal of the amplifier.   The input device according to claim 1, wherein the first liquid crystal lens includes a plurality of concentric transparent electrodes.   The input device according to claim 1, wherein the second liquid crystal lens includes a plurality of linear transparent electrodes arranged in parallel.

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