JP3742634B2 - Position detection device - Google Patents

Description

  The present invention relates to a position detection device that optically detects the position of an object, and more particularly to a position detection device in which a retroreflective material is provided only on one side of a detection region.

  Various types of position detection devices, such as digitizers, that detect the position of an object have been developed. Some of them detect the position of an object optically, and mainly include a reflection method and a blocking method. In the reflection method, a film of light is made in a predetermined position detection area, and when the position detection area is indicated with a special pen or the like with a retroreflective material, the light hit the retroreflective material of the pen is retroreflected. This is a method of detecting an indicated position by detecting with an image sensor and measuring the position. In the blocking method, a retroreflective frame is placed around the position detection area, light is emitted toward the retroreflective frame to form a film of light, and when the position detection area is indicated with a finger or the like, the instructed finger is affected. Therefore, the shadow is detected by an image sensor and the position is measured to detect the indicated position.

  FIG. 1 shows a blocking type position detection device. FIG. 1 is an example of a general optical position detection device using the principle of a position detection device as disclosed in Patent Document 1. A retroreflective frame 2 is provided so as to cover the three sides of the position detection region 1. And the detection unit 3 is arrange | positioned in two places of the both ends by the side of the opening part of the retroreflection frame 2. FIG. The detection unit 3 is mainly composed of a light source that emits light such as an LED and an image sensor such as a CCD. Since the image sensor only needs to detect that a finger or the like is placed in the detection area, a linear image sensor is usually used. The light emitted from the light source of the detection unit 3 enters the retroreflective frame 2 over the position detection region 1, retroreflects there, and returns to the detection unit 3 through the position detection region 1. The light that has been retroreflected and returned is detected by the image sensor of the detection unit 3. In order to allow the image sensor to receive the light emitted from the light source and retroreflected, the light source and the image sensor are arranged close to each other. Alternatively, the optical path is divided by using a half mirror or the like so that the optical axes coincide. When the finger 4 is placed in the position detection region 1, a part of the light from the light source is blocked and detected as a shadow by the image sensor. By measuring the position of this shadow from two places on the left and right, the coordinate of the designated position of the finger 4 can be calculated using the principle of triangulation.

  The retroreflective frame 2 is a member having a reflection characteristic in which light incident on the retroreflective frame 2 returns straight in the incident direction. As a typical retroreflective material, a retroreflective sheet in which a large number of small transparent glass beads are embedded, There are corner cube prisms arranged on an array. These retroreflective properties are relatively excellent, and even if the incident angle is not right but oblique, most of it returns to the incident direction. However, as shown in FIG. 2, when the shape of the position detection region 1 is vertically long, in other words, when the detection unit 3 is arranged on the short side of the position detection region 1, as the distance from the detection unit 3 increases, The incident angle of light on the retroreflective frame 2 becomes smaller. For this reason, in the vicinity of the end portion 2a of the retroreflective frame 2, the incident angle becomes a small incident angle exceeding the retroreflected incident angle, and the retroreflective frame is not retroreflected. If it is not retroreflected, the part is detected as a shadow by the image sensor, so that it may be mistaken for the finger 4 or cannot be detected even if the finger is placed in the shadow.

  Therefore, as shown in Patent Document 2, as shown in FIG. 3, by placing a sawtooth portion 2b made of a retroreflective material at the position of the end 2a of the retroreflective frame 2, the light enters the vicinity. The incident light is incident on the sawtooth portion 2b almost perpendicularly, so that the retroreflection characteristic can be prevented from deteriorating.

JP-A-62-2428 JP-A-11-85377

  The optical position detection device is easy to increase in size due to its structure, and a touch panel combined with a large plasma display device has been developed. When combined with such a general display device, since the display device itself has a peripheral frame such as a bezel, the position detection device can be incorporated so as not to be noticeable to some extent. However, in an apparatus for projecting an image with a projector or the like, when a touch sensor is to be incorporated in a wall surface or glass plate as a screen, the conventional position detection apparatus must surround at least three sides with a retroreflective frame. Because of this, the frame was a design limitation. Usually, it is preferable that the touch sensor is installed so as not to be conspicuous so that the user is not aware that the touch sensor is incorporated. However, in the conventional position detection device, since the retroreflective frames must be provided on three sides, the portion has to be unnatural due to design limitations.

  Further, when trying to realize a vertically long position detection region, as described above, the retroreflective characteristic of the portion far from the detection unit is deteriorated, and the position of the indicator in that portion cannot be measured. By providing the sawtooth portion as in Patent Document 2, this problem is solved. However, in this case, the structure becomes complicated in addition to the design problem, leading to an increase in cost. Also, the maintainability was poor.

  Further, in the conventional optical position detection device of the blocking type, the retroreflective frames must be provided on the three sides, so that the position detection area is necessarily rectangular. Therefore, it has been impossible to make the position detection region in an arbitrary shape from the problem of retroreflective characteristics and the problem of design.

  In view of such circumstances, the present invention is intended to provide a position detection device that is free from design restrictions, is easy to maintain, and can be installed at low cost.

  In order to achieve the above-described object of the present invention, a position detection apparatus according to the present invention includes a sensor unit that detects the position of a shadow of an object, and a detection unit that includes a light source unit that emits light in the direction of the detection region. And a retroreflective material that is provided only on one side of the detection region, covers all or a part of the visual field of the detection unit, and retroreflects light from the light source.

  Here, the retroreflective member may be provided at a position facing the detection unit and provided at a position sandwiching the detection region with the detection unit.

  Further, the detection unit may be provided at two places, and the two-dimensional coordinates of the object may be detected by the principle of triangulation in the detection region where the visual fields of the detection units intersect.

  Furthermore, the detection unit may be provided on any one of the ceiling surface, floor surface, and wall surface of the building, and the retroreflective member may be provided on any one of the ceiling surface, floor surface, and wall surface of the building.

  The detection area may be a part of any one of the ceiling surface, floor surface, and wall surface of the building.

  Furthermore, the detection area may include the display surface of the display device.

  Furthermore, the detection area may be a part of a glass surface, and the display device may be a projector having a part of the glass surface as a screen.

  It is also possible to expand the detection area by connecting detection areas where the detection units are provided at three or more locations and the visual fields of the detection units intersect.

  The sensor unit of the detection unit may be an area image sensor.

  Further, the detection area may be an area in which an area where the detection of the object is permitted can be arbitrarily set.

  Still further, the retroreflective material can be provided on a surface having at least one of a linear shape, an arch shape, and a step shape.

  Since the position detection device of the present invention does not need to provide retroreflective frames on three sides, there is an advantage that a touch panel can be formed anywhere without being restricted in design.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 4 is a front view for explaining the position detection apparatus according to the first embodiment of the present invention. The illustrated example represents the simplest configuration and has specifications that can detect only one-dimensional coordinates. In the figure, the same reference numerals as those in FIG. 1 denote the same parts. The position detection apparatus of the first embodiment is provided with a detection unit 3 for detecting the left and right positions of the object 4 in the detection area 1 and outputting the detection information. The detection unit 3 includes a sensor unit that detects the position of the shadow of the object 4, such as a linear image sensor of a CCD, and a light source unit that emits light in the direction of the detection region 1, such as an LED. The configuration around this is basically the same as that of the optical position detection device of the conventional example.

  The most characteristic feature of the present invention resides in the arrangement of the retroreflective material. The retroreflective material 2 of the present invention is provided only on one side of the detection region 1 as shown in FIG. That is, in the conventional position detection device, the retroreflective material is provided on three sides so as to cover the detection region. However, in the present invention, the retroreflective material is provided only on the detection region one side, that is, with the detection unit 3. It is provided at an opposing position. Therefore, the detection unit 3 and the retroreflective material 2 are arranged so as to sandwich the detection region 1, and the retroreflective material 2 is arranged so as to include all or part of the visual field of the detection unit. Is done.

  Light emitted from the light source of the detection unit 3 passes through the detection region 1 and enters the retroreflecting material 2. The incident light is retroreflected by the retroreflecting material 2, returns to the incident direction, that is, the direction of the light source, passes through the detection region 1 again, and is received by the sensor unit of the detection unit 3. Then, when an object 4 such as a finger is placed in the detection area 1, the portion is detected as a shadow by the sensor unit, and thus the lateral position of the object 4 can be calculated by measuring the direction of the shadow. .

  Here, for example, the detection unit and the retroreflective member can be provided on any one of a ceiling surface, a floor surface, and a wall surface of a building. If it demonstrates using FIG. 4, the detection unit 3 may be installed in a floor surface, and the retroreflection material 2 may be installed in a ceiling surface. In this case, a part of the wall surface of the building becomes the detection region 1. The present invention is not limited to this example, and the detection unit may be provided on the ceiling surface and the retroreflective material may be provided on the floor surface. Even if the retroreflective material is provided on the wall surface, the present invention can be applied if retroreflective is possible.

  In the present invention, it is only necessary to provide the retroreflective material on only one side of the detection region in this way, so that it becomes possible to install the position detection device in any object and place without any restriction on the design.

  Even if only one-dimensional coordinates of the indicator can be detected, for example, if a picture of a piano keyboard is pasted on a wall and the position detection device of the present invention is applied thereto, the wall can be used as a musical instrument. .

  Next, a position detection apparatus according to a second embodiment of the present invention will be described. In the first embodiment, the position detection device can detect only one-dimensional direction, but in the second embodiment, two-dimensional position coordinates can be detected. FIG. 5 is a front view for explaining a second embodiment of the present invention. As shown in the figure, in this embodiment, two detection units 3 are used. By providing the detection units 3 at two locations, the two-dimensional coordinates of the object 4 can be detected using the principle of triangulation in the detection region where the fields of view of the respective detection units intersect. That is, if the positions of the two detection units and the shadow position in each detection unit are known, the object position coordinates can be calculated by the principle of triangulation. Since other principles, structures, etc. are the same as those of the first embodiment of the present invention, a duplicate description is omitted.

  If the position detection device of the present invention is incorporated in a wall surface that becomes a screen of a device that projects an image by a projector or the like, the screen becomes a touch panel. In the front projection type, the shadow of the pointing finger or the like may affect the display screen. However, in the case of the rear projection type projector, there is no such influence.

  In the present embodiment, since the two-dimensional coordinates can be detected if the field of view of the two detection units 3 overlaps, an area in which detection of an object is permitted can be arbitrarily set in this area. . Therefore, if the field of view overlaps, a vertically long detection region that has been difficult in the past can be easily realized. In the prior art, the detection area is limited to a quadrangle. However, according to the present invention, since a retroreflective frame surrounding the detection area is unnecessary, a favorite area like the detection area indicated by 1 'in FIG. Since the shape can be set, for example, it is possible to determine the detection region in accordance with a picture drawn on a poster or the like. This makes it possible to ignore an object input outside the detection area, for example, a place that is not a picture.

  According to the present invention, as shown in the drawing, it is not necessary to provide a retroreflecting material in the lateral direction surrounding the detection region, and it is only necessary to provide the retroreflective material in a straight line at opposing positions across the detection region. Therefore, installation is also easy. Note that the retroreflective material of the present invention does not necessarily have to be provided at a position facing the detection unit. For example, as shown in FIG. 6, the detection unit is placed on the floor, and the retroreflective material is placed on the wall as shown in FIG. Of course, it is also possible to provide them. In other words, the retroreflective material is provided only on one side of the detection region, and may be installed anywhere as long as the light from the light source can be retroreflected.

  Thus, since the position detection device can be arranged very simply, it can be configured such that the touch sensor is not incorporated at first glance. Since the user can be made unaware of the touch sensor, a very simple touch panel display device can be realized by combining with a display device as described in detail below. Further, since the structure is simple, maintenance is easy.

  FIG. 7 is a diagram for explaining an application example of the position detection apparatus according to the second embodiment of the present invention. FIG. 7A is a front view, and FIG. 7B is a side view. First, a display device to which the present invention is applied will be described. A glass plate 11 is provided from the floor surface to the ceiling surface. This may be a show window or a window glass. A projector 12 is provided behind the glass plate 11 to project an image rearward toward the display screen 10 of the glass plate. For example, a holographic screen for Glass Vision (registered trademark) manufactured by Denso Corporation is attached to the display screen 10 in order to form an image. The hologram screen is a special film on which a precise diffraction grating is formed, and has a function of bending light like a prism. This function works only when projector light is projected from 35 degrees above or below, for example, and can reproduce it as an image. When the video is not displayed, it is transparent and without a sense of pressure, and it is always transparent from the back of the screen and does not obstruct the view. In addition, since no wiring is required on the screen, the display device is such that an image appears on an empty glass surface. In addition, although the detection unit 3 can be confirmed in the illustrated example, it is actually hidden from the outside by a blindfold plate or the like.

  In this way, when the screen is a display device of a glass plate, one of the features is that it can be projected on an empty glass surface, so if you apply a conventional position detection device here , The retroreflective frame gets in the way, which is not preferable in terms of design. However, according to the present invention, it is possible to set and arrange the detection region 1 according to the display screen 10 by arranging the detection unit 3 on the floor side of the front surface of the glass plate 11 and the retroreflective material on the ceiling side. Because it is possible, there is no need to install anything on the glass plate surface, and there are no design restrictions. Further, it is not necessary to provide electrical wiring for the touch sensor on the glass plate itself. Therefore, a touch panel display device that not only looks like an image on a glass surface with nothing but also a touch panel that responds accordingly when touched further has such a consciousness from the appearance. It becomes feasible without.

  Next, a position detection apparatus according to a third embodiment of the present invention will be described. FIG. 8 is a front view for explaining a third embodiment of the position detecting apparatus of the present invention. In the second embodiment, the detection units are arranged in two places so that the two-dimensional coordinates can be detected. However, in the third embodiment, the detection units are provided in three or more places, and the fields of view of the respective detection units intersect. The detection area is enlarged by connecting the detection areas. As shown in the figure, the detection units 3 are arranged at equal intervals with a predetermined interval in the lateral direction. Thereby, it is possible to widen the detection region 1 in the horizontal direction by connecting the portions where the visual fields of adjacent detection units intersect. The retroreflective material 2 is arranged longer than the case of two detection units so as to cover the field of view of each detection unit 3 in accordance with the lateral expansion. The detection of the designated position is performed based on the principle of triangulation using a pair of adjacent detection units that detect shadows. In addition, depending on the location of the detection area, the shadow may be detected not only by the adjacent detection units but also by three detection units. In this case, it may be controlled to use detection units that are not adjacent to each other. This measurement is possible by controlling the output of the detection unit as desired. In the illustrated example, an example using four detection units is shown. However, the present invention is not limited to this, and any number may be used as long as space is allowed.

  In the above description, the retroreflective member 2 has been illustrated as being linear, but the present invention is not limited to this, and the ceiling is arched, for example, as shown in FIG. However, the retroreflective material 2 can be attached along the ceiling. What is necessary is just to be comprised so that the light from the light source of the detection unit 3 may be retroreflected and returned to an image sensor. Furthermore, as shown in FIG. 10, even if there is a beam on the ceiling, the present invention can be applied only by pasting the retroreflective member 2 along the beam. Thus, as long as the retroreflective material covers the field of view of the detection unit, the present invention can adjust the position even if it is arched, stepped, or even obliquely angled. It is possible to detect.

  Next, a position detection apparatus according to a fourth embodiment of the present invention is described. FIG. 11 is a side view for explaining a fourth embodiment of the position detecting apparatus of the present invention. In the embodiments described so far, it is only necessary to be able to detect whether or not a finger or the like is placed in a detection area within a plane. Therefore, in principle, the image sensor of the detection unit may be a linear image sensor. This embodiment is characterized in that an area image sensor is used instead of a linear image sensor as the image sensor of the detection unit. For example, as shown in FIG. 11, the field of view of the area image sensors of the two detection units is provided with a depth from the wall surface of the glass plate 11 or the like to the front side. Then, the retroreflective member 2 is provided on the ceiling surface in, for example, a quadrangular shape so as to encompass the visual field of the detection unit. The retroreflective member 2 may be provided so as to have a retroreflective surface that covers all regions of the field of view of the detection unit, or a recursive material that includes only a desired partial region of them. You may provide so that it may have a reflective surface. With this configuration, the detection area 1 is expanded into a three-dimensional space, and the three-dimensional coordinates of the indicator 4 can be detected.

  In the position detection device constructed as described above, not only the designated position coordinates of a finger or the like placed on the display screen 10, but also that the person is approaching the screen, the position of the person, and the direction in which the person is facing are detected. It is also possible to do. Accordingly, the video displayed on the display screen 10 can be changed in accordance with these operations. Therefore, if it is used in a show window or the like, the advertising effect of the product can be expected.

  In the above example, the detection unit is provided in two places and the three-dimensional coordinates are configured to be detected. However, the present invention is not limited to this, and the detection unit is provided in one place. It doesn't matter. In this case, although the coordinate in the height direction cannot be detected, the coordinate in the depth direction can be detected. Therefore, it is possible to detect whether or not a person has approached the display screen 10. Therefore, when it is desired to reduce the cost, it is also effective to use only one detection unit.

  Furthermore, in this embodiment, even if there are one or two detection units, it is possible to discriminate from the shape of the shadow to the position of the person's nose, so that not only the person approached but also the orientation of the person's face is discriminated. It becomes possible. Therefore, it is possible to display an image corresponding to this orientation.

  Note that the position detection device of the present invention is not limited to the illustrated examples described above, and it is needless to say that various changes can be made without departing from the scope of the present invention. For example, the retroreflective material only needs to be provided on one side of the detection region, and the installation position is not limited to the ceiling surface, floor surface, or wall surface. Further, the position detection device of the present invention detects not only a device that accurately grasps the indicated position, such as a display device with a touch panel function combined with a display device, but also simply detects whether a person is present or not. It can also be applied to other security sensors.

FIG. 1 is a diagram for explaining an example of a conventional blocking-type position detection device. FIG. 2 is a diagram for explaining a case where the position detection region has a vertically long shape in a conventional blocking-type position detection device. FIG. 3 is a diagram for explaining an example in which a problem in the case where the shape of the position detection region is vertically long is solved in a conventional blocking-type position detection device. FIG. 4 is a front view for explaining the position detection apparatus according to the first embodiment of the present invention. FIG. 5 is a front view for explaining the position detecting apparatus according to the second embodiment of the present invention. FIG. 6 is a front view for explaining an example in which the detection unit is provided on the floor surface and the retroreflective material is provided on the wall surface in the position detection device of the present invention. FIG. 7 is a diagram for explaining an application example of the position detection apparatus according to the second embodiment of the present invention. FIG. 8 is a front view for explaining a position detection apparatus according to a third embodiment of the present invention. FIG. 9 is a front view for explaining a case where the retroreflective material is pasted in an arch shape in the position detection device of the present invention. FIG. 10 is a front view for explaining the case where the location where the retroreflective material is pasted is stepped in the position detection device of the present invention. FIG. 11 is a side view for explaining a position detection apparatus according to a fourth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Position detection area 1 Detection area 2 Retroreflective material 3 Detection unit 4 Object 10 Display screen 11 Glass plate 12 Projector

Claims (7)

A position detection device for detecting a three-dimensional coordinate position of an object in a detection region and outputting the detection information, the position detection device comprising:
An area image sensor unit for detecting the position of the shadow of an object, and a light source unit that emits light in the direction of the detection region possess respectively, and at least two detection units provided in mutually at predetermined intervals,
Provided at a position opposite to the respective detection units, encompasses all planar region or a part of the surface area of the field of view of the detection unit, a retro-reflective material to the retroreflective light from the light source unit,
A position detection apparatus comprising:   The position detection device according to claim 1, wherein the detection unit is provided on any one of a ceiling surface, a floor surface, and a wall surface of the building, and the retroreflective member is any one of the ceiling surface, the floor surface, or the wall surface of the building. A position detecting device provided in the apparatus. The position detecting device according to claim 1 or claim 2, wherein the detection area, the position detecting apparatus characterized by including the display surface of the display device. The position detection device according to claim 3 , wherein the detection area is a part of a glass surface, and the display device is a projector having a part of the glass surface as a screen. The position detecting device according to any one of claims 1 to 4, wherein the detecting unit is provided in three or more locations, that the field of view of each detection unit is larger detection area by connecting the detection region intersecting A position detection device. The position detecting device according to any one of claims 1 to 5, wherein the detection region, said by adjusting the installation area of the retroreflective material, object detection can be arbitrarily set the three-dimensional region to allow the A position detecting device characterized by being an area. The position detecting device according to any one of claims 1 to 6 , wherein the retroreflective member is provided on a surface having at least one of a linear shape, an arch shape, and a step shape. Detection device.