JPS60176129A - Digitizer - Google Patents

Abstract

PURPOSE:To obtain a digitizer with very high reliability without being affected by external disturbance by allowing a coordinate detection means to detect a coordinate from a position receiving a light irradiated at a coordinate indicating means. CONSTITUTION:The light irradiated from a light emitting element 3 of a coordinate indicator 7 is given to a CCD2 of a coordinate board 1 as a spot light through a small hole 6 after passing through an optical system 4 and a filter 5. The stored electric charge photoelectric-converted at the CCD2, is fed to a vertical transfer register 8 by using a clock 30 of a clock generation circuit 12 of an indicating coordinate detection means 16, vertical column information is transferred sequentially and outputted as a signal Vout18 through a horizontal transfer register 9 and an amplifier circuit 10. In order to detect only a point on which the spot light from the indicator 7 is touched, the strength of the point is compared with a reference strength 19 by a comparator circuit 11 in the means 16 so as to obtain a pulse DaTa 20 for position information, and the X, Y coordinates are extracted and given to a host computer 17 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a digitizer, and more particularly to a digitizer having a light emitting means and a light receiving means and capable of reading absolute coordinates.

[Prior art] Various methods are known for conventional digitizers, such as a method in which coordinate values are obtained from the voltage drop value due to a resistor, and an electromagnetic induction method. However, in either case, the structure is complex and the digitizer is susceptible to external disturbances. There were drawbacks such as being easy to use.

[Objective] The present invention aims to eliminate two drawbacks of the prior art, and provides a digitizer that detects coordinate positions using light, has high precision, has a relatively simple structure, and is not affected by external disturbances. It's about doing.

[Example] An example of the present invention will be described in detail below with reference to the drawings. In the drawings, the same components are given the same numbers.

FIG. 1 is a schematic diagram of a digitizer according to an embodiment of the present invention, in which coordinates are input by moving a coordinate indicator 7 on an input coordinate plate l. To briefly explain the operation, the coordinate indicator 7
A spot light is applied to the coordinate plate 1 from inside the coordinate plate 1, converted into an electric signal by the photoelectric conversion elements 2 arranged in a matrix, detected as X coordinates by the coordinate detection circuit 16, and transferred to the host computer 17, etc.

The case where a CCD area sensor is used for the coordinate plate 1 will be described in detail below with reference to FIGS. 2 to 4.

FIG. 2 is a diagram showing a cross section of the coordinate indicator 7 having a light emitting element and a cross section of the coordinate plate. In the figure, 1 is the coordinate plate used for input, and as shown in FIG. ,
) 2 are arranged in a matrix. Also, the coordinate board l
A coordinate indicator 7 is placed above and includes means for shining a spotlight on the CCD 2 to specify the position. In the coordinate indicator 7, 3 is a light emitting element, and the light emitted by the light emitting element 3 passes through an optical system 4 and a filter 5, and then is given to the CCD 2 as a spot light through a small hole 6 made in the coordinate indicator 7.

Next, FIG. 3 shows a block diagram of the configuration of the coordinate detection means that detects the spot light given to the COD 2 and detects the input position.

In the figure, 8 is a vertical transfer register of the CCD 2 on the coordinate plate 1, 9 is a horizontal transfer register, and 10 is an amplifier circuit. Also photoelectric conversion device (COD) 2
The accumulated charges are then photoelectrically converted and sent to the vertical transfer register 8 by the clock signal 30 of the clock circuit 12. At this time, since the heavy transfer is performed simultaneously for each pixel, it is possible to detect images at the same time.

Then, the vertical column information is sequentially transferred to the horizontal transfer register 9, and then the horizontal transfer register 9 and the amplifier circuit 1.
0, and the optical input information v at the same time on the plane is output as an analog C serial signal Vout18. The waveform sample is shown in FIG. 4(a).

Since this Vout 18 is a voltage signal proportional to the light irradiated to the CCD 2, the coordinate detection circuit 20 removes the influence of disturbance light and compares it in order to detect only the point hit by the spot light from the coordinate indicator 7. Reference intensity V through circuit 11
The position information pulse Da is compared with ref 19.
Get ta20.

It is necessary to extract position information from Data 20 by dividing it into X coordinate and X coordinate, but this is done by clock generation circuit 1.
Clock pulses φ5γ21 and φCX2 generated from 2
2. Conducted using φCγ23.

In C0D2, the value "0" of the vertical transfer register 8 is sequentially sent to the horizontal transfer register 9 as shown in 41i4(a) by the read clock signal 30 from the clock generation circuit 12.

The value of "l" of the vertical transfer register 8 is output as ut18, and then the value of "l" of the vertical transfer register 8 is sequentially outputted as the horizontal transfer register 9.
rN of 4B direct transfer register 8
The value of -IJ is sent to the horizontal transfer register 9, and the value "0" of the vertical transfer register 8 is sent to the horizontal transfer register 9 again. For this reason, Figure 4 (
Data a20 signal (7) shown in b)
After resetting a, a new horizontal transfer register 9
This counter [X] 13a is counted up by φC〆22 that is output every time reading of Data starts, and the value of this counter [X] 13ac7) is obtained by latching it into the latch [X] 14& at the output timing of Data a20. .

Similarly, the counter [Y] 13b is reset at φ22, which is also the reading start timing of the vertical transfer register 8, and is then output every time the value of the horizontal transfer register 9 is read, that is, every time the Y-direction data of the vertical transfer register 8 is read. is counted up by φcY23, and the value of this counter [Y]13b is set to Da.
Latch [Y]14. at the output timing of t a20. By latching to b, the Y coordinate heading can be obtained.

Thereafter, the information is converted into a serial signal for transfer by the serial conversion circuit 15 and sent to the host 17.

In the above embodiment, the coordinate indicator 7 is moved by the "-" of the coordinate plate l, but as shown in FIG. If it is led to the board 1, the size of the input board 25 can be made variable, and the resolution can also be controlled.

These can also be realized by configuring discrete elements such as first transistors instead of the CCD area sensor as in the embodiment and by changing the element spacing. Also,
If a MOS sensor is used instead of a CCD sensor, the former can obtain surface information at the same time, whereas the latter scans pixels, making it possible to read a CRT display like a rask scan.

[Effects] As explained below, according to the present invention, the light emitted by the coordinate indicating means is received by the coordinate position detecting means, and the incident position of the light can be detected to obtain the coordinate position. without being affected by noise.

A very reliable digitizer can be provided.

In addition, the coordinate indicating means does not require any communication circuit other than the light emitting means, has an extremely simple structure, and has a built-in power source such as a battery, thereby eliminating the need for troublesome cords such as information cables. It is possible to provide a digitizer that can be used in various ways, and in addition, the shape can be freely selected.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a digitizer according to an embodiment of the present invention, FIG. 2 is a sectional view showing a coordinate indicator having a light emitting element according to this embodiment, and FIG. 3 is a photoelectronic device arranged in a matrix according to this embodiment. Coordinate plate using CCD area sensor as a conversion element, X coordinate,
A block diagram of the Y coordinate detection means, FIG. 4 is a timing chart explaining the method of detecting the X and Y coordinates in this embodiment shown in FIG. 3, and FIG. 5 is an optical diagram of another embodiment of the present invention. FIG. 2 is a diagram showing a configuration in which the resolution of a target zoom device is made variable. In the figure, 1...coordinate plate, 2...photoelectric conversion element, 3...
- Light emitting element, 7... Coordinate indicator, 8... Vertical transfer register, 9... Horizontal transfer register,
10...Amplifier 1, 11...Comparison circuit, 12...
Clock generation circuit, L3a, 13b-counter, 14a
. 14b...Latch, 15...Parallel-serial conversion circuit, 16...Instruction coordinate detection means, 17...Host computer, 18...Optical input information, 19...Reference voltage, 20... ...Position information pulse, 21...Clear pulse, 22.23...Count pulse (X). (Y), 24...Zoom optical system, 25...Input board. Patent applicant: Canon Co., Ltd. Figure 1 Figure 2 Figure 5 Figure 3

Claims (1)

[Claims] The coordinate position detecting means includes a coordinate indicating means having a light emitting means and a coordinate position detecting means having light receiving means arranged in a matrix, and the coordinate position detecting means detects the coordinate position from the position where the light emitted by the coordinate indicating means is received. A digitizer characterized by detecting.