JP2002132435A - Method and device for position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical digitizer that can detect with touch in the vicinity of a detector plane. SOLUTION: The optical digitizer that detects the position coordinate of an indicator on a detector plane is equipped with a light source that beams light rays, and a recurrence reflex member that reflects recursively light rays beamed from the light source is arranged around the detector plane, and imaging method for detecting a direction of shadow that occurs when the indicator blocks the recurrence reflex light from the recurrence reflex member, and image focusing lens for imaging the recurrence reflex light. And the optical digitizer is also equipped with a mirror glass on both side of the image focusing lens that reflects light beamed from the light source, or a mirror glass in front of the image focusing lens that reflects imaging visual field, and the light source on both side of the mirror glass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a light-blocking type optical digitizer that detects a pointing position coordinate of a pointer on a detection surface. In particular, the present invention relates to an optical digitizer having a reduced height at which the touch of the indicator on the detection surface is detected.

[0002]

2. Description of the Related Art In place of digitizers of the resistive film type or the electromagnetic induction type, optical digitizers having higher accuracy in detection have been receiving attention. FIG. 5 shows an example of an optical digitizer using a linear image sensor. FIG. 5 (a)
FIG. 2 is a schematic plan view of an optical digitizer. FIG. 5 (b)
It is a side view of the partial cross section. As shown in the drawing, when a pen 2 serving as a pointer is placed on the detection surface 1, two detection units 3 provided above the detection surface 1 detect the pointing position coordinates based on the principle of triangulation. is there. The detection unit 3 has a configuration in which the LED light source 11 is arranged on the imaging lens 9 of the linear image sensor 13 as shown in FIG. When there is nothing blocking light on the detection surface 1, light from the detection unit 3 passing through the detection surface 1 and entering the retroreflective member 22 passes through the opposite optical path and enters the detection unit 3. Come back. When the pen 2 or the like is placed on the detection surface 1, a part of the optical path of light is blocked, and the light does not return to the detection unit 3. Since the shadow portion can be imaged by the image sensor 13, the direction in which the light is blocked can be detected by detecting the direction of the shadow. That is, if the direction in which the pen 2 exists can be detected by the detection units 3 and 3 at two different known positions, the pointing position coordinates of the pen 2 can be calculated based on the principle of triangulation.

[0003]

However, in the example shown in FIG. 5, as shown in FIG. 6, before the pen touches the detection surface (while the pen is floating), the LED light source 11 is turned off.
The touch detection is performed at the time when the light beam emitted from the light source and traveling toward the retroreflective member 22 is blocked. For this reason, there is a problem that when characters such as kanji are to be written with a pen, they continue to be characters. Further, in a touch operation with a finger, touch detection is performed without feeling that the detection surface has been touched, resulting in poor operability.

[0004] In view of such circumstances, an object of the present invention is to provide an optical digitizer capable of performing touch detection near a detection surface.

[0005]

Means for Solving the Problems In order to solve the above problems, a position detecting device according to the present invention includes a light source that emits a light beam to detect a pointed position coordinate of a pointer located on a detection surface, and the light source. A retroreflective member provided around the detection surface to retroreflect light rays emitted from the light source, and a direction for detecting a direction of a shadow caused by the pointer blocking retroreflective light from the retroreflective member. A position detecting device including an imaging unit and an imaging lens that forms the retroreflected light on the imaging unit, further including a mirror unit that bends a light beam emitted by the light source on the left and right sides of the imaging lens.

Further, the mirror means may be a curved mirror, and may also have a function of condensing or diffusing the light beam of the light source. The light source may be provided at left and right positions of the imaging lens and the curved mirror, and emit light rays from a direction approximately parallel to the detection surface toward the curved mirror.

A position detecting device according to the present invention includes a light source that emits a light beam for detecting a designated position coordinate of a pointer located on a detection surface, and a light source that emits a light beam emitted from the light source. A retroreflective member provided around, and imaging means for detecting a direction of a shadow generated by the pointer blocking the retroreflected light from the retroreflective member,
A position detecting device having an image forming lens for forming an image of the retroreflected light on the image forming means, wherein a mirror means for bending an imaging field of view is provided on a front surface of the image forming lens; It has a light source.

Further, the mirror means may be configured as a part of a lens member of the imaging lens.

A position detection method according to the present invention includes a light source that emits a light beam for detecting a designated position coordinate of a pointer located on a detection surface, and a light source that emits a light beam emitted from the light source. A retroreflective member provided around, and imaging means for detecting a direction of a shadow generated by the pointer blocking the retroreflected light from the retroreflective member,
An imaging lens for imaging the retroreflected light on the imaging unit;
A position detecting method for a position detecting device, comprising: mirror means positioned on the left and right sides of the imaging lens to bend light rays emitted by the light source, wherein the light source emits light rays toward the mirror means; A light beam bending step in which the mirror means bends the light beam emitted in the step toward the detection surface, and a light beam that reaches the detection surface in the light beam bending step is reflected by a retroreflective member provided around the detection surface. The method includes a retroreflection step for reflection, and an imaging step for detecting, by an imaging means, a direction of a shadow generated by the light reflected in the retroreflection step.

The light beam bending step may also have a function of condensing or diffusing light beams of the light source.

A position detection method according to the present invention includes a light source that emits a light beam for detecting a pointing position coordinate of a pointer located on a detection surface, and a light source that emits a light beam from the light source for retroreflection. A retroreflective member provided around, and imaging means for detecting a direction of a shadow generated by the pointer blocking the retroreflected light from the retroreflective member,
An imaging lens for imaging the retroreflected light on the imaging means; and a mirror means positioned in front of the imaging lens, wherein the light source is provided adjacent to the left and right sides of the mirror means. A position detecting method of a position detecting device, wherein the light source emits a light beam toward the position detecting surface, and a light beam reaching the detecting surface in the light emitting step is recursively provided around the detecting surface. A retroreflection step of reflecting by the reflection member, a light beam bending step of bending the light beam reflected in the retroreflection step by the mirror means toward the imaging lens, and a direction of the light beam bent in the light beam bending step And an imaging step of detecting by the imaging means.

Further, the mirror means is configured as a part of a lens member of the imaging lens, and the bending and the imaging can be realized by one refractor.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Portions denoted by the same reference numerals as those used in a plurality of drawings represent the same components.

FIG. 1 is a diagram showing a preferred embodiment of the optical digitizer of the present invention. In order to solve the above problems, the inventor of the present invention needs to minimize the difference between the angle of the light beam emitted from the light source toward the detection surface and the angle at which the retroreflected light beam enters the linear image sensor. Noticed. However, when the light source is arranged beside the imaging lens, the light source hits the lens, the image sensor, and the optical path therebetween. So when I thought about it,
It has become clear that it is effective to bend the light beam with mirror means in order to further reduce the difference in angle between the two light beams, even if the size of the light source (light emitting diode) or the size of the members of the linear image sensor is reduced. Then, the configuration shown in FIG. 1 was devised.

FIG. 1A shows the positional relationship among a linear image sensor 13, an imaging lens 9, a light source (light emitting diode) 11 and a mirror 12 inside a detection unit 3, which is a main part of the position detection device of the present invention. FIG. FIG.
(B) shows the positional relationship among the linear image sensor 13, the imaging lens 9, the light source (light emitting diode) 11 and the mirror 12 inside the detection unit 3, which is a main part of the position detection device of the present invention, in the traveling direction of light rays FIG. 3 is a diagram viewed from the position of FIG. As shown in the figure, the light source is arranged downward, and its traveling direction is bent by about 90 degrees by the mirror 12, so that the heights of the light beam going and returning from the detection surface can be made equal. In addition, as shown in FIG. 1B, the mirror 12 can be arranged immediately near the imaging lens 9. 5 and 6
Is a member having a function of returning a light beam in the same direction as the direction in which the light beam came, and in a commonly used member, if the direction goes wrong once, the amount of light is reduced to one-tenth.
To a degree. Therefore, it can be said that the arrangement shown in FIG. 1 has a meaning to obtain a sufficient signal intensity.

FIG. 1C is a diagram showing an example in which the mirror in the embodiment is changed to a cylindrical concave mirror. In FIG. 1A, the mirror is a plane mirror. However, the mirror may be a cylindrically curved mirror so that light rays of a light source having a spread are condensed in a vertical direction to be a beam parallel to the detection surface. By using a curved mirror as the mirror in this way, the light beam of the light source can be used efficiently for touch detection and coordinate detection of the pointer. here,
The cylindrical curved mirror refers to a mirror having a cylindrical curved surface.

[0017]

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a diagram showing an embodiment in which light sources are arranged on the left and right using a cylindrical mirror. This figure is a plan view, and the inside of the detection unit 3 is viewed from above. Cylindrical concave mirrors 25 are arranged on both left and right sides of the imaging lens 9, respectively, and the light source 1 is arranged on both sides as shown in the figure.
1 is arranged. A linear image sensor 13 is placed at a position where an image of the imaging lens is formed. With this configuration, light from the light source is emitted at the same height (or almost the same height) as the height of the light beam incident on the linear image sensor 13 (the height from the detection surface 1 for detecting the position of the pen 2). It is possible to throw it on the position detection surface.

FIG. 3 is a diagram showing an embodiment in which the linear image sensor is arranged downward. FIG. 3A illustrates the light beam from the side, and FIG. 3B illustrates the light beam from the traveling direction. In this embodiment, the light source 11 emits a light beam straight toward the detection surface without being bent. The linear image sensor 13 is arranged downward. And
The retroreflected light beam from the retroreflective member 22 provided around the detection surface 1 is bent by approximately 90 degrees by the mirror 12 and enters the linear image sensor 13. Also in this embodiment, the heights of the two light beams from the detection surface can be substantially the same.

FIG. 4 is a diagram showing an embodiment in which the imaging lens and the mirror member are configured by one optical member. This embodiment is a modification of the embodiment in which the linear image sensor shown in FIG. 3 is arranged downward. When the linear image sensor is arranged downward, light incident on the linear image sensor is bent by a light beam bending unit (mirror unit), and immediately thereafter, is refracted by an imaging lens. The inventor of the present invention has considered that the mechanism of the detection unit of the present invention can be further simplified by configuring the mirror and the lens as one integrated optical member. FIG. 4A is a diagram of this embodiment viewed from the side, and FIG. 4B is a diagram of the embodiment viewed from the traveling direction of light rays. A feature of the present invention is that an imaging lens with mirror 19 is provided instead of the mirror 12 and the imaging lens 9 shown in FIG.

FIG. 7 shows a method for manufacturing an imaging lens with a mirror. FIG. 7A is a diagram of the convex lens viewed from the traveling direction of the light beam, and FIG. 7B is a diagram of the convex lens viewed from the side. This convex lens has a spherical surface on one side and a flat surface on the other side. As shown in FIG.
Cut into three parts 42 and 43 and cut 41 and 43
Is discarded, and 42 is taken out and used. Further, the end portion on the plane side is cut at an angle of 45 degrees as shown in FIG. The imaging lens with mirror 19 shown in FIG. Since the surface cut at 45 degrees is totally reflected by the same principle as the prism, it functions as a mirror. Although this manufacturing method has been described in order to easily explain the configuration of the imaging lens 19, the same product can be manufactured by another manufacturing method.

The optical digitizer of the present invention is not limited to the illustrated example described above, and it is needless to say that various changes can be made without departing from the gist of the present invention. For example, an optical digitizer having a large detection surface can be realized by realizing the left and right light sources as a set (a plurality of LEDs) of a plurality of LEDs. This is an effect that can be realized by the present invention, which alleviates restrictions on the space of the light source.

[0022]

As described above, according to the optical digitizer of the present invention, it is possible to provide an optical digitizer capable of performing touch detection in the vicinity of the detection surface, so that the pen tip touches or separates from the detection surface. Since an object can be accurately detected, an optical digitizer suitable for character recognition can be provided. In addition, even in a touch operation by a finger, an actual effect that an operator senses that the finger touches the detection surface and a touch detection of the device coincide with each other, so that an excellent effect that an optical digitizer with good operability can be provided can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an optical digitizer of the present invention.

FIG. 2 is a diagram showing an embodiment in which light sources are arranged on the left and right using a cylindrical mirror.

FIG. 3 is a diagram showing an embodiment in which a linear image sensor is arranged downward.

FIG. 4 is a diagram showing an embodiment in which the imaging lens and the mirror member are configured by one optical member.

FIG. 5 is a diagram showing an optical digitizer using a linear image sensor.

FIG. 6 is a diagram illustrating a problem of an optical digitizer using a linear image sensor.

FIG. 7 is a diagram for explaining a method of manufacturing the imaging lens and the mirror member when the members are constituted by one optical member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detection surface 2 Pen 3 Detection unit 9 Imaging lens 11 Light source (light emitting diode, LED) 12 Mirror 13 Linear image sensor 19 Imaging lens with mirror 22 Retroreflective member 24, 25 Cylindrical concave mirror

Claims (9)

[Claims] 1. A light source that emits a light beam to detect a pointing position coordinate of a pointer located on a detection surface, and a retroreflective member provided around the detection surface to retroreflect the light beam emitted from the light source. And an imaging unit for detecting a direction of a shadow generated by the pointer blocking the retroreflection light from the retroreflection member, and an imaging lens for imaging the retroreflection light on the imaging unit. A position detecting device comprising: mirror means for bending a light beam emitted by the light source on both sides of the imaging lens. 2. The position detecting device according to claim 1, wherein the mirror means is a curved mirror, and has a function of condensing or diffusing light rays of the light source. 3. A light source that emits a light beam to detect a pointing position coordinate of a pointer located on a detection surface, and a retroreflective member provided around the detection surface to retroreflect the light beam emitted from the light source. Imaging means for detecting a direction of a shadow generated when the pointer blocks the retroreflection light from the retroreflection member; and an imaging lens for imaging the retroreflection light on the imaging means. A position detecting device comprising: mirror means for bending an imaging field in front of the imaging lens; and the light source on the left and right of the mirror means. 4. The position detecting device according to claim 3, wherein the mirror unit is configured as a part of a lens member of the imaging lens. 5. A light source that emits a light beam for detecting a pointing position coordinate of a pointer located on a detection surface, and a retroreflective member provided around the detection surface for retroreflecting a light beam emitted from the light source. And imaging means for detecting the direction of a shadow generated by the pointer blocking the retroreflection light from the retroreflection member, and an imaging lens for imaging the retroreflection light on the imaging means, A position detecting method for a position detecting device, comprising: mirror means positioned on the left and right of the imaging lens to bend light rays emitted by the light source, wherein the light source emits light rays toward the mirror means; A light beam bending step in which the light beam emitted in the step is bent by the mirror means and directed to the detection surface; and a light beam reaching the detection surface in the light beam bending step is provided around the detection surface. A position detecting method comprising: a retroreflecting step of reflecting by a retroreflective member obtained; and an imaging step of detecting, by an imaging unit, a direction of a shadow generated by the light reflected in the retroreflecting step. 6. The position detecting method according to claim 5, wherein the step of bending the light beam also has a function of condensing or diffusing a light beam of the light source. 7. A light source that emits a light beam to detect a pointing position coordinate of a pointer located on a detection surface, and a retroreflective member provided around the detection surface to retroreflect the light beam emitted from the light source. Imaging means for detecting a direction of a shadow generated when the pointer blocks the retroreflection light from the retroreflection member; and an imaging lens for imaging the retroreflection light on the imaging means. And a mirror means located in front of the imaging lens, wherein the light source is provided near the left and right of the mirror means. A light emitting step of emitting a light beam toward the surface, a light beam reaching the detection surface in the light emitting step is reflected by a retroreflective member provided around the detection surface, and the light beam is reflected in the retroreflection step. Light A position detecting method comprising: a light beam bending step in which a line is bent by the mirror means toward the imaging lens; and an imaging step of detecting, by an imaging means, a direction of the light beam bent in the light beam bending step. 8. The position detecting method according to claim 7, wherein the mirror unit is configured as a part of a lens member of the imaging lens, and the bending and the imaging are realized by one refractor. Position detection method. 9. The position detecting device according to claim 2, wherein the light source is provided at left and right positions of the imaging lens and the curved mirror, and the curved mirror is arranged substantially in a direction parallel to the detection surface. A position detection device that emits light rays toward.