JPS63292222A - Coordinate input device - Google Patents

Abstract

PURPOSE:To detect the coordinate position of a point indicator, by arranging an optical system which image-forms an image in the neighborhood of the upper plane of an original being positioned in a direction perpendicular to a read original including the point indicator in the periphery of the read original, and performing the image processing of a picture signal obtained by image- picking up the image in the neighborhood of the upper plane of the original image-picked up by the optical system. CONSTITUTION:An image pickup device 3 image-picks up an image pickup area 11 including the read original 1, an X-direction refecting mirror 9, and a Y-direction reflecting mirror 10, and its output picture signal is stored in a picture memory. At this time, the tip of a write pen 2 on the read original 1 is image-picked up directly by the image pickup device 3 as shown in a alternate long and short dash line (a), and is reflected and image-picked up by the reflecting mirrors 9 and 10 as shown in broken line (b), and the content of the picture memory 5 is shown as in figure. In other words, it is possible to obtain the coordinates (x) and (y) of the tip of the pen by detecting the (x-z) picture 15 and the (y-z) picture 16 of the write pen.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a coordinate system that uses an imaging device such as a TV camera to input positional coordinates on an object such as a manuscript into a computer or the like.

[Conventional technology]

2. Description of the Related Art As a coordinate input device, a coordinate input device using an imaging device such as a TV camera or a camera-type image scanner has been proposed. Compared to coordinate input devices such as tablets and mice, this type of coordinate input device has the following advantages: (1) No need for a special plane table for inputting coordinates (2) No need for signal cables for point pointing devices (3) Only coordinate input required It also has the advantage that image data can also be input. FIG. 6 shows, for example, the Journal of the Institute of Electronics and Communication Engineers Vol. J67-D, No. 6.1984 P726-P723
1 is a schematic configuration diagram showing a conventional coordinate input device shown in "Video Tablet - Coordinate Input Device Using CD Camera" published in 2007. In the figure, 1 is a reading document, 2 is a writing pen as a point pointing tool, 3 is an imaging device such as a TV camera that simultaneously images the reading document 1 and the writing pen 2, and 4 is reading the image and detecting the coordinates of the writing pen 2. 5 is an image memory that stores the output image signal of the imaging device 3; 6 is a display device such as a CRT display that displays the stored contents of the image memory 5 as an image; 7 is controlled by the controller 4, and This is an image processing device that processes image data stored in a memory 5 to detect an image of the writing pen 2. Next, the operation will be explained. The imaging device 3 images the entire document 1 to be read and the writing pen 2 at a rate of 30 frames per second or 60 frames per second, and the output image signal is stored in the image memory 5. The image processing device 7 is controlled by the controller 4, and when operating as an image scanner, it transfers the contents of the image memory 5 as is to a file memory (not shown), etc., and when operating as a coordinate human-powered device, it performs so-called image processing. The image of the writing pen 2 is detected from the image signal. This image processing involves pattern matching between a pen tip detection matching mask 8 consisting of a 7x7 pixel block in which each pixel has three values of white, gray, and black, as shown in FIG. 7, and a partial area of the image. , is a combination of commonly known processing methods such as pre-processing (noise removal, dark value processing, etc.) on the input image for performing this matching, and the image processing device 7 is a dedicated processing method for performing these processing at high speed. It is a device. Then, the image of the writing pen 2 is detected, and the address on the image memory 5 where the image signal corresponding to a specific portion such as the tip of the writing pen is stored is output to the controller 4. The controller 4 obtains the coordinates specified by the writing pen 2 by converting this address into coordinates on the read document 1. If the operation speed of the image processing device 7 is sufficiently high, the speed of the coordinate human power of the above image processing (that is, the number of times the coordinate values of a point can be obtained per second) will be as high as the imaging speed of the imaging device 3 (30 frames, 60 frames per second). If it is not sufficiently large, it is determined by the operating speed of the image processing device 7. For example, if the image of the writing pen 2 can be detected only 15 times per second through image processing, the controller 4 controls the image signal in the image memory 5 to be updated only once every two frames.

[Problems to be solved by the invention]

Since the conventional coordinate input device using an imaging device is configured as described above, in order to realize high-speed coordinate input, image processing for detecting the tip of the writing pen 2 by the image processing device 7 is performed. The matching mask for pen tip detection shown in FIG. 7 (7x7 pixel block, For example, when the resolution of the input image is 51, the pattern matching process between the input image (three values/pixel) and all partial regions (7x7 pixel sub-blocks) of the input image is performed.
For 2x512 pixels, pattern matching processing is required approximately 512x512 times. Therefore, if a TV camera with an imaging speed of 30 frames per second and an input image resolution of 512x512 is used as the imaging device 3, the pattern matching process will be performed in real time. In order to detect the pen tip of writing pen 2, 1
The processing time for pattern matching is 0.128μse.
The image capturing speed is approximately 30 frames per second with a high-resolution coordinate input device using a TV camera for high-definition television. Since the resolution is 1920xl125, the processing time for one pattern matching is within 0.064 μSec, which requires a very high-speed image processing device 7, and such a high-speed image processing device requires a large scale device. Coordinate input devices that can input coordinates in real time with respect to the imaging speed have problems in that they are large in size and very expensive. This was done in order to solve such problems, and the purpose is to obtain a coordinate input device that is small in scale and inexpensive even when inputting coordinates in real time using a high-resolution imaging device. shall be.

[Means to solve problems] The coordinate input device according to the present invention includes an optical system including a point indicator and forming an image near the top surface of the document in a direction perpendicular to the document to be read, and an optical system that forms an image near the top surface of the document in a direction perpendicular to the document to be read. The image signal obtained by capturing an image near the top surface of the document formed by this optical system is image-processed to detect the coordinate position of the point indicator. [For use]

The coordinate input device of the present invention uses an optical system to form an image near the top surface of the document in a direction perpendicular to the document to be read, and uses an imaging device to capture the document surface of the document to be read and the image near the top surface of the document including a point indicator. The document surface obtained based on only the image signal corresponding to the vicinity of the top surface of the document, or the image signal corresponding to the vicinity of the top surface of the document and the image signal in the image signal output by the imaging device. An image processing device performs image processing on a portion of the image signal corresponding to the image signal including the image of the point pointing tool to detect the coordinate position of the point pointing tool.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is a reading document, 2 is a writing pen, 3 is an imaging device, 4 is a controller, 5 is an image memory, 6 is a display device, and 7 is an image processing device, and these are given the same reference numerals in FIG. Since this is the same or equivalent part to the conventional one, the explanation will be omitted. Further, reference numerals 9 and 10 refer to reflectors serving as an optical system for forming an image in the X direction and Y direction including the writing pen 2 near the top surface of the original document 1 on the imaging device 3, and 11 indicates an imaging area of the imaging device 3. It is. In addition, FIG. 2 is an explanatory diagram showing the imaging situation, and FIG. 3 is an explanatory diagram showing an example of the captured image.
11 is the reading manuscript 1. X direction reflector 9° Y direction reflector 10
12 is a read original area corresponding to the read original 1, and 13 is an area near the Z direction (near the top surface of the read original 1) corresponding to the X direction reflecting mirror 9 and the Y direction reflecting mirror 10. , 14 is an xy plane image of the writing pen, 15 is an X-2 plane image of the writing pen, and 16 is a yz plane image of the writing pen. Next, its operation will be explained. In the coordinate input device configured as described above, the imaging device 3 reads the document 1. Imaging area 11 including an X direction reflector 9 and a Y direction reflector 10
is imaged, and its output image signal is stored in the image memory 5. At this time, the pen tip of the writing pen 2 on the original document l is directly imaged by the imaging device 3 as shown by the dashed line (a) in FIG. It is reflected by 9 and 10 and is imaged. The contents of the image memory 5 when an image is captured in this manner are as shown in FIG. 3, for example. That is, in the read original area 12 corresponding to the read original 1 in the imaging area 11, there is a writing pen xy plane image 14 which is an image of the writing pen 2 that has been directly imaged.
In the Z direction vicinity region 13 corresponding to the reflecting mirrors 9 and 10,
There are a writing pen x-z plane image 15 and a writing pen y-2 plane image 16, which are images of the nib of the writing pen 2 in the Z direction reflected by the reflecting mirrors 9 and 10. As is clear from FIG. 3, in order to detect the coordinates of the pen tip of the writing pen 2, the image processing described in the conventional example is performed only on the Z-direction neighborhood area 13, and the writing pen x-z image 1
5 and the writing pen y-z plane image 16, the X and y coordinates of the pen tip can be obtained. Therefore, the image processing device 7 performs preprocessing such as noise removal and darkness value processing, and pattern matching processing for pen tip detection only on the Z-direction neighboring region 13 of the image memory 5, and performs pattern matching processing for detecting the pen tip of the writing pen 2. X ahead. The y-coordinate is detected and output to the controller 4. Furthermore, the content of the image memory 5 is displayed as an image of only the read original area 12 by a CRT controller (not shown). By the way, the size of the Z-direction neighboring region to be subjected to the image processing described above may be within a range that allows detecting the pen tip of the writing pen 2 and determining whether or not the pen tip is in contact with the scanned document 1; In general, the size in the vertical and horizontal directions of the document 1 to be read may be 2 to 3 times the size of the nib of the writing pen 2 in the Z direction. For example, a reading document 1 of 30 x 30 oa and a writing pen 2 having a nib of 1c+++ are
When capturing an image with a resolution of 12 x 512 pixels, the number of pixels corresponding to the size of the pen tip is approximately 16 pixels, and 2 pixels in the Z direction.
The number of pixels in the Z-direction neighboring area 13, which is twice the size, is 16.
X2X512X2=32768 pixels. This allows the pen tip of the writing pen 2 to be detected with 12.5% of the amount of processing compared to the case where image processing is performed on the entire imaging area 11 of 512×512=262144 pixels as in the conventional example. In the above embodiment, the point pointing tool is a writing pen, and the shape thereof is detected by an image processing device. However, the point pointing tool can be separated and identified from the image signal by the image processing device. It can be any object. For example, a thin cross-shaped object may be used to detect the intersection of the crosses using an image processing device, or an image sensor that can input colors (for example, an image sensor with a color filter) may be used to read a document. It goes without saying that by using a pen-shaped indicator of a different color to identify the color using an image processing device, it is possible to detect a point indicator and input coordinates. In addition, in the above embodiment, two reflecting mirrors were used to capture an image near the top of the document as seen from the X and A similar effect can be obtained by performing image processing on a part of the image signal including the image of the writing pen in the image signal and the image signal corresponding to the document surface, and detecting the image of the writing pen. FIG. 4 shows an example in which the imaging area 11 is imaged using only the X-direction reflecting mirror 9. In the figure, numeral 17 is a writing pen existing area, and the other areas correspond to those in FIG. 3. In this embodiment, first, a region 1 near the Z direction with respect to the X direction is
Image processing for detecting the pen tip similar to that in the embodiment shown in FIG. Next, image processing for pen tip detection similar to the detection of the writing pen y-z plane image 16 in the embodiment shown in FIG. Do, writing pen z-y
The surface image 14 is detected and the X coordinate of the writing pen 2 is determined. The width of this writing pen presence area 17 is equal to the width of the matching mask for pen tip detection as shown in FIG. The area required is smaller than that of the neighboring region 13. Furthermore, in addition to having the same effect as the embodiment shown in FIG. 1, this embodiment also has two
The direction vicinity area 13 is no longer needed in the image memory 5,
The capacity of the image memory 5 can be saved. Further, in the above embodiment, a background plate 18 painted in white or the like as shown in FIG. By preventing background images other than the image of the operator's hand from being captured, image processing for pen tip detection can be facilitated. In addition, in the description of the above embodiment, a TV is used as an imaging device.
Although the explanation has been made using a camera, it is clear that similar effects can be obtained by using an imaging device such as a camera-type image scanner using a -dimensional imaging device.

【Effect of the invention】

As described above, according to the present invention, an optical system that forms an image in the vicinity of the top surface of a document in a direction perpendicular to the document to be read is disposed around the document to be read, and an image is formed by this optical system in an image processing device. An image of the area near the top of the document including the point indicator is captured,
Since the obtained image signal is image-processed to detect the coordinate position of the point pointing tool, the amount of image signal processed by the image processing device is significantly reduced, and a small-scale and inexpensive image processing device can be used. Even if used, the effect is that coordinate input with a fast response speed can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a coordinate input device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing its imaging situation, and FIG.
FIG. 4 is an explanatory diagram showing the captured image, FIG. 4 is an explanatory diagram showing the image captured in another embodiment of the present invention, and FIG.
6 is a schematic block diagram showing still another embodiment of the present invention, FIG. 6 is a schematic block diagram showing a conventional coordinate input device, and FIG. 7 is an explanatory diagram showing a matching mask for detecting a pen tip. In the figure, 1 is the original to be read, 2 is the writing pen (point indicator)
, 3 is an imaging device, 7 is an image processing device, 9 is an X-direction reflecting mirror (optical system), and 10 is an X-direction reflecting mirror (optical system). In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent applicant: Mitsubishi Electric Corporation - ~ 1st year: Hajime Zanmi (〉Harudomari Flea Watch

Claims (3)

[Claims] (1) an optical system that is disposed around a document to be read and forms an image near the top surface of the document in a direction perpendicular to the document to be read, and the top surface of the document including the point indicator formed by this optical system; an imaging device that images a nearby image and the document surface of the read document including the point pointing tool and outputs an image signal; and an imaging device that performs image processing on the image signal output from the imaging device to determine the coordinates of the point pointing tool. A coordinate input device including an image processing device that detects a position. (2) The optical system is arranged in the X direction and the Y direction of the original to be read, and the image processing device uses the image signal of the original imaged by the optical system in the X direction and the Y direction. 2. The coordinate input device according to claim 1, wherein the coordinate position of the pointing device is detected using only image signals corresponding to the vicinity of the top surface. (3) The optical system is disposed only in the X or Y direction of the original to be read, and the image processing device uses the image signal output from the imaging device in the X or Y direction that is imaged by the optical system. Detecting the coordinate position of the point pointing device using an image signal corresponding to the vicinity of the top surface of the document and an image signal corresponding to a part of the document surface including the point pointing device obtained as a result of processing the image signal. A coordinate input device according to claim 1.