JP3349818B2 - Coordinate detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate detecting apparatus, and more particularly, to a coordinate detecting apparatus suitable for a handwriting input system or a shape measuring system capable of detecting two-dimensional coordinates or three-dimensional coordinates with one linear image sensor. The present invention relates to a detection device.

[0002]

2. Description of the Related Art In a handwriting input system, for example, in order to optically detect the position of a stylus, a plurality of one-dimensional position detectors combining a single slit and a linear image sensor are generally used. .

That is, two linear image sensors are arranged along the XY plane to mount a light source on a stylus and detect its two-dimensional coordinates. Another linear image sensor is arranged along the axial direction.

[0004]

However, conventionally, two-dimensional coordinate detection requires two one-dimensional position detectors, and three-dimensional coordinate detection requires three one-dimensional position detectors. Becomes expensive,
There is a drawback that the whole apparatus becomes large.

Accordingly, it is an object of the present invention to provide a coordinate detecting device capable of detecting not only two-dimensional coordinates but also three-dimensional coordinates with one linear image sensor.

[0006]

In order to achieve the above object, the present invention provides a position indicating section including a light source which emits light directly or indirectly, and a light receiving section for receiving the light from the light source. In a coordinate detecting device comprising: coordinate detecting means for detecting two-dimensional coordinates or three-dimensional coordinates, the coordinate detecting means includes: a linear image sensor for receiving light emitted from the light source; Imaging means arranged along a plane parallel to the surface to change the position of light incident on the linear image sensor in accordance with the position of the light source; and the position based on a detection signal output from the linear image sensor. Calculating means for calculating the coordinates of the pointing unit, wherein the imaging means is oriented at a predetermined interval so as to be orthogonal to the pixel array direction of the linear image sensor. And first and second imaging element, a third that is oriented at a predetermined angle with respect to those of the imaging element
An imaging element, and the calculating means calculates two-dimensional coordinates or three-dimensional coordinates of the position indicating unit from the value of the light receiving position imaged on the linear image sensor via the three imaging elements. It is characterized by detecting.

In this case, the inclination angle of the third imaging element is
45 with respect to the pixel array direction of the linear image sensor
Degree is preferred. Each of the above-mentioned imaging elements can be constituted by a slit or a cylindrical lens.

[0008] In the present invention, the arithmetic means includes:
A distance D between the first and second imaging elements, a distance d1 between a pixel position of the linear image sensor corresponding to the origin of the three-dimensional coordinates and a light receiving position by the first imaging element, the first imaging The distance d2 between the element and the light receiving position by the third imaging,
Distance d between the first imaging element and the light receiving position by the second imaging
3 to detect the three-dimensional coordinates of the position indicating unit.

According to the above arrangement, the X and Z coordinates of the position indicating section are detected by the positions of the incident light by the first and second imaging elements orthogonal to the pixel arrangement direction of the linear image sensor. The coordinates in the Y-axis direction are detected by the position of the incident light by the third imaging element having an angle of, for example, 45 degrees with respect to the direction.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view of the coordinate detecting device. According to this, the coordinate detecting device includes a linear image sensor 10 that receives light from a light source P provided on a position indicating unit, for example, a stylus of an optical digitizer. In this case, as the light source P,
In addition to a device that directly emits light, a device that receives light from another light source and emits light indirectly, such as a phosphor, may be used.

The linear image sensor 10 is a CCD
(Charge Coupled Device) may be a known pixel in which pixels are linearly arranged,
In front of the light receiving surface (imaging surface), a slit plate 20 as an imaging unit is arranged.

The slit plate 20 is arranged along a plane preferably parallel to the light receiving surface of the linear image sensor 10, and in the present invention, three slits 21 to 23 are formed.

In this case, the first slit 21 and the second slit 22 are formed at a predetermined interval along a direction orthogonal to the pixel arrangement direction of the linear image sensor 10, while the third slit 23 is It is provided so as to intersect at an angle of 45 degrees with the pixel array direction.

Light is incident on the linear image sensor 10 through each of the slits 21 to 23, and the three-dimensional coordinates of the light source P are obtained by the CPU 30 as arithmetic means based on the three incident light positions. The principle will be described with reference to FIGS. FIG. 2 is a perspective view schematically showing a relationship between three-dimensional X, Y, and Z axes and each of the slits 21 to 23 and an image formed on the linear image sensor 10 through the slits. XY of 2
FIG. 4 is a sectional view taken along the line ZY of FIG.

In FIG. 2, reference numerals 21a and 22a denote incident light positions formed on the imaging surface of the linear image sensor 10 through the first slit 21 and the second slit 22, respectively. This is the incident light position where an image is formed on the imaging surface of the image sensor 10.

The incident light positions 21a to 23a change as follows according to the movement of the light source P. That is, for example, when the light source P moves in a direction approaching or moving away from the slit plate 20 while keeping the height position constant, the distance between the incident light positions 21a and 22a changes. When the light source P moves up and down with the distance from the slit plate 20 being constant, the third slit 23 is formed obliquely, so that the incident light position 23a is shifted in the pixel array direction of the linear image sensor 10. Will move left and right along.

Here, as shown in FIGS. 3 and 4, the pixel position of the linear image sensor 10 corresponding to the origin O of the three-dimensional coordinates (in this example, the pixel position located on the extension of the Z axis) And the incident light position 2 by the first slit 21
1a, and the distance between the incident light position 21a and the incident light position 23a by the third slit 23 is d1.
2. The distance between the incident light position 21a by the first slit 21 and the incident light position 22a by the second slit 22 is d.
3, the first slit 21 on the slit plate 20
D, the distance between the linear image sensor 10 and the slit plate 20 is L, and the optical path from the light source P to the incident light position 23a and the third slit 23
Let the distance in the X-axis direction from the origin O of the intersection point of S be S and the coordinates of the light source P be (x, y, z), the following equation holds. Since the inclination of the third slit 23 is 45 degrees, the distance in the Y-axis direction from the origin O at the intersection point is also S.

(From FIG. 3) d1: L = x: z D: d3 = z: z + L S: d2 = z: z + L (From FIG. 4) S: L = y: z + L Therefore, the coordinates (x, x = {D / (d3-D)} × d1 y = {D / (d3-D)} × d2 z = {D / (d3-D)} × L According to the present invention, three-dimensional coordinates of the light source P are obtained by one linear image sensor 10. Further, the horizontal angle θ (see FIG. 3) and the vertical angle (elevation angle) φ (see FIG. 4) with respect to the light source P are obtained by the following equations.

The horizontal angle θ = arctan (X / Z) = arctan (d1 / L) The vertical angle φ = arctan (Y / Z) = arctan (d2 / L) This means that the first and second slits 21 are formed. , 22 means that the horizontal and vertical directions with respect to the light source P can be detected by two slits, for example, the first slit 21 and the third slit. Also, in other words, assuming that the Z coordinate value is constant, the X
-Two-dimensional coordinates on the -Y plane can be detected.

Therefore, if this coordinate position detecting device is mounted on the side of a movable body such as a human body, it can be used as the posture detecting device. For reference, FIG. 5 shows an example in which a posture detection device based on such a concept is applied to a goggle-type image display device as a virtual reality system.

First, the outline of the image display device will be described. The image display device has a goggle 40 mounted on the head of a human body. Are provided. Therefore, the user looks at the display screens of the displays 42, 42,
You can enjoy virtual reality as if the screen is displayed on the full screen of the theater.

The goggles 40 are, for example, relatively 90
Two slits 4 oriented in a V-shape with a degree angle
3 and 43 are provided, and a linear image sensor 44 is disposed behind the linear image sensor 44 in this regard. Then, a detection signal of the linear image sensor 44 is input to the image processing computer 41 via a predetermined interface 45.

In use, the light source P is arranged at a reference position sufficiently distant. By taking the light from the light source P into the linear image sensor 44 through the two slits 43, 43, the orientation of the user's head is relatively determined by the above-described formula for calculating the horizontal angle θ and the vertical angle φ. That is, the line-of-sight vector direction is determined, the data is input to the computer 41, and the displays 42, 42
Is switched.

In addition to this, the posture detecting apparatus is also applicable to the case where the posture (direction) of a machine tool such as a robot or a surveying machine is detected. In the above reference example, the two slits 43, 43 are oriented in a V-shape with an angle of 90 degrees, but the angle between them and the angle with respect to the pixel array can be set arbitrarily provided that they are not parallel to each other. It is possible. For example, one slit may be orthogonal to the pixel array direction of the linear image sensor 44, and the other slit may be inclined at 45 degrees.

As the image forming means for the linear image sensors 10 and 44, cylindrical lenses 51 and 52 as shown in FIG. 6 can be used instead of the slits.

Further, the slit plate 2 shown in FIG.
0, the arrangement of the slits 21 to 23 is the first and second in the vertical direction as illustrated in FIG.
45 degree third slit 23 between slits 21 and 22
May be formed, and this modified example is also applied to a case where a cylindrical lens is used.

[0027]

As described above, according to the present invention,
One linear image sensor can detect the three-dimensional position of a light source provided on, for example, a stylus of an optical digitizer, so that costs can be significantly reduced and the entire device can be downsized. Can be.

Further, even with a single linear image sensor, it is possible to detect, for example, a line-of-sight vector direction (viewing direction) and a posture (direction) of an object toward a reference light source. Therefore, due to its compactness, for example, even if it is worn on the human body, there is little discomfort, and it is possible to construct a posture input system or a computer interactive virtual reality system with excellent operability. You.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view illustrating an embodiment of a coordinate detection device according to the present invention.

FIG. 2 is a schematic diagram perspectively showing a relationship between three-dimensional X, Y, and Z axes, slits, and an image formed on a linear image sensor through the slits in the embodiment.

FIG. 3 is an XY cross-sectional view of FIG. 2;

FIG. 4 is a sectional view taken along the line ZY of FIG. 2;

FIG. 5 is an explanatory diagram showing a goggle type image display device having a posture detecting unit as a reference example.

FIG. 6 is a schematic diagram illustrating a case where a cylindrical lens is used as an image forming unit.

FIG. 7 is an explanatory diagram showing a modification of the present invention in which the arrangement of slits as imaging means is changed.

[Explanation of symbols]

 10, 44 linear image sensor 20 slit plate 21 to 23, 43 slit 21a to 23a incident light position 30 CPU 40 goggle 41 image processing computer 42 display 51, 52 cylindrical lens

Claims (3)

(57) [Claims] 1. A position indicating unit including a light source that emits light directly or indirectly, and coordinate detecting means for receiving light from the light source and detecting two-dimensional coordinates or three-dimensional coordinates of the position indicating unit. in the coordinate detecting device including, the coordinate detection means comprises a linear image sensor for receiving the light emitted from the light source, disposed along the imaging plane parallel to the plane of the linear image sensor, the position of the light source Image forming means for changing the position of light incident on the linear image sensor in accordance with the condition, and calculating means for calculating coordinates of the position indicating section based on a detection signal output from the linear image sensor. image means includes first and second imaging elements which are oriented at a predetermined interval so as to be perpendicular to the pixel arrangement direction of the linear image sensor, for these imaging elements And a third imaging element that is oriented at a predetermined angle, said calculating means, the value from the position instruction section through the three imaging elements were imaged on the linear image sensor receiving position A coordinate detecting device for detecting three-dimensional coordinates of the coordinates. 2. The tilt angle of the third imaging element is defined by the linear
45 degrees with respect to the pixel array direction of the image sensor
The coordinate detecting device according to claim 1, wherein: 3. The computing means according to claim 1, wherein
The distance D between the image elements and the above
The pixel position of the near image sensor and the first imaging element
Distance d1 between the light receiving positions, the first imaging element and the third imaging
The distance d2 between the light receiving positions by the image, the first imaging element and the
The above-mentioned position indication is made from the distance d3 between the light receiving positions by two imagings
The three-dimensional coordinates of the part are detected.
The coordinate detecting device according to the above.