JPS5963580A - Position correcting device of semiconductor optical position detector - Google Patents

Abstract

PURPOSE:To improve the distortion of a position linearity characteristic to a semiconductor optical position detector, and to utiliz the advantage of the high resolution of the semiconductor optical position detector by obtaining corrected coordinates from the output signal of the optical position detector and correcting a dot in measure. CONSTITUTION:A two-dimensional semiconductor optical position detector 1 has four output terminals A-D; X-directional coordiniate data is found from signals from the terminals A and B, and Y-directional coordinate data is obtained by signals from the terminals C and D. Currents outputted from the terminals A-D of the detector 1 are amplified by amplifiers 21A-21D, and sampled and held by sample holding circuits 22A-22D. An analog multiplexer 23 switches the output signals of the sample holding circuits 22A-22D successively and inputs them to an A/D converting circuit 24. The A/D converting circuit 24 converts the input signal into a digital signal, which is inputted to a microprocessor 25 which processes the A/D-converted signal. The processor 25 refers to a tape in a storage circuit 26 to correct a measurement signal, and outputs the resulting signal to a display device 27.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a position correction device for a semiconductor device detector that outputs a position signal in analog form according to a light incident position.

Semiconductor device detectors that divide the charge current using a semiconductor surface resistance layer have the advantage that there is no dead area on the light receiving surface and a continuous position signal is received compared to optical position detectors such as a 7-otodiode array. On the other hand, since the linearity is determined by the characteristics of the surface resistance layer, there is distortion, and the distortion varies depending on the individual detector.

An object of the present invention is to provide a position correction device for improving the linearity of a semiconductor device detector having such drawbacks.

The present invention will be explained below based on embodiments shown in the drawings.

FIGS. 1(a) and 1(b) are diagrams for explaining the present invention in detail, and FIG. 1(a) shows nXn on the light receiving surface 1 of the optical position detector (n -6) divided into squares,
Figure 1(b) is a diagram in which (n+1)'' (49 in the figure) reference points are set at approximately equal intervals, and is based on the output signal from the optical position detector 1 corresponding to each of the reference points. , Fig. 1 is a diagram showing an example of a reproduction of the light-receiving surface 1'.
), it is clear that the nth square represented by the output signal of the optical position detector 1 is generally distorted. However, the first f is extremely accurate.
This becomes a problem when you want to detect l. ) Each reference point is associated in advance with the output signal from the optical position detector 1 corresponding to each reference point on a one-to-one basis, and the coordinate P (
The coordinates of the reference point P (Xp,
By determining Y'p) and setting it to 0, the error at each reference point is eliminated. In this way, the light-receiving surface of the optical position detector 1 is subdivided into small tracing regions, and the cumulative error is reduced.At the points inside the square f defined by the four reference points, there is no influence of distortion. The corrected coordinates are determined by assuming that the output signal changes uniformly depending on the coordinate position.

That is, now - for example, four reference points T l j
+Ti+t, J, Ti+l, j++, 'l
'l, I ++ Point P(Xp, Y
If the coordinates obtained from the output signal of the optical position detector 1 corresponding to 'p) are p<Xp, yp), then the coordinates p(Xp,
The X coordinate Xp and the y coordinate yp of Yp) are uniquely expressed by Formula 1. However, XI), Y+) are the X coordinate, Y coordinate, and L of point P.
The length of one side of the square forming the square,
+ I coordinates (X, + t, Y, coordinates corresponding to J, XI, yr are the coordinates of the reference point Ti + l + I"l (
coordinates corresponding to +t, Y*+t),
, '/+ is the coordinate (X, .) of the reference point T+, 4++.

Y'L + t), m is the X coordinate x,
, X, and the division ratio between the X coordinates x, , x, 11
are the y coordinates y, , yr and the y coordinates 'fi, Ys
This is the division ratio between

By finding the values of the division ratio m and n from the above equation (1), the coordinates (xp, Yp) of point P in Fig. 1(a) can be obtained.
Equation 1 (%)) Therefore, the coordinate P(
The corrected coordinates (Xp, Yp) can be found from the coordinates (Xp, Yp). By correcting the points inside the square in this way, if the distortion of positional linearity is %, the four points forming each square are completely included in the correction, so the points inside the square The linearity distortion of fl- will be improved by 11 times.

Next, FIG. 2 shows a block diagram of an electric circuit that realizes the above-mentioned principle.

The two-dimensional semiconductor device detector 1 has four output terminals A, E,
C, , D, coordinate data in the X direction is determined by signals from terminals A and B, and coordinate data in the Y direction is determined by a signal from terminal C1D. Terminal A of detector 1; B
The currents output from XC and D are as shown in equations (3) and (4).

However, ■Xl + lx, l IYI + iY, are the currents output from terminals A1B and CXD, respectively, ■ is the current generated by the incident light energy, and Ll is the current generated by the electrodes A and B.
LI is the distance between electrodes C and D, x and y are the coordinates of point P when the origin is the lower left corner O of detector 1, Xpyp (
(see FIG. 1(b)).

The currents of the amplifiers 21A, 21B, 21C,
After being amplified by 21D, sample bold circuit 2
Sample bold at 2A, 22B, 22C, and 22D. The analog multiplexer 23 includes sample/hold circuits 22A, 22B, 22C, 221)
The output signals are sequentially switched and inputted to the A/D conversion circuit 24.

The A/D conversion circuit 24 converts the long sword signal into a digital signal, and inputs this A/D conversion signal to the microprocessor 25 as a processing circuit. The microprocessor 25 refers to a table in a storage circuit 26 in which a correction table is stored, performs appropriate correction on the measurement signal, and outputs it to the display device 27.

As is clear from the explanation using FIG. The coordinates corresponding to each reference point are stored in a one-to-one relationship.

Therefore, to explain the operation of the microprocessor 25 based on the flowchart shown in FIG. For example, the microprocessor 25 simply reads the coordinates of the reference point corresponding to the calculated coordinates from the storage circuit 26, and displays the read coordinates on the display device 27.
(Block 30.31.32.33)
. However, if the calculated coordinates are inside each reference point, the microprocessor 25 reads out the coordinates of the four reference points surrounding the calculated coordinates from the storage circuit 26, calculates the division ratio mXn, and further calculates the division ratio mXn. Of the two reference points,
The coordinates (X,, Y.) corresponding to the reference point TB, which is the origin, are calculated, and the calculation is performed according to equation (2) to find the corrected coordinates (Xp.) corresponding to the coordinates determined from the output signal of the optical position detector 1.

Yp) (block 30.31.32.33.3
4).

Thereafter, the microprocessor sensor 25 outputs the corrected coordinates (Xp, Yp) determined in the block 34 to the display device +t27 (block 32).

As described above, according to the present invention, the distortion in positional linearity peculiar to semiconductor device detectors is improved and the advantage of the high positional resolution of the detector can be utilized in the first semiconductor device.

[Brief explanation of the drawing]

1(a) and 1(b) are diagrams for explaining the present invention in detail, FIG. 2 is a block diagram of a simple embodiment of the present invention, and FIG. 3 is the microprocessor sensor of FIG. 2. 25 is a flowchart. [Explanation of symbols of main parts] 1... Semiconductor device detector, 24...k
/D conversion circuit, 25... microprocessor,
26... Memory circuit. Sai 1 figure (6)

Claims (1)

[Claims] In a position correction device for a semiconductor device detector that outputs an analog position signal according to a light incident position, reference points are set at approximately equal intervals on the light-receiving surface of the detector, and the reference points of the reference points are a storage device that stores a digital conversion signal of a position signal in correspondence with the coordinates of the reference point; an A-D conversion circuit that converts the position signal output from the detector into a tental (g); and the storage device and the A-D conversion circuit.
- A position correction device comprising: a correction injection device that corrects the position of the output signal of the D conversion circuit as a point inside the reference point.