JPS5899884A - Optical scanning position compensating device - Google Patents

Abstract

PURPOSE:To compensate fluctuation of scanning without performing any complicated position correction at every position, by arranging a reference plate having plural position marks so as to intersect the whole scanning lines perpendicularly, and processing signals influenced by the reference plate. CONSTITUTION:A plate 1 on which marks M1-M<n> are printed at regular intervals in advance, is successively scanned by a flying spot scanner FSS2 controlled by an X counter 3. The reflecting light is photoelectrically converted by a photomultiplier 4 and quantized by an AD converter 5. The center position of the quantized mark pattern is found in a mark detecting circuit 6 and the counted value of the FSSX counter 3 for the detected center position is stored in a memory 7. When this operation is repeated for the number of marks N and all marks are detected, each measured value is read out from the memory 7 and correlation between each mark is operated by an operator 8. When a regression line is determined in this way, fluctuation of the scanning can easily by compensated by determining the scanning position by the regression line thereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical scanning position correcting device for correcting an optical scanning position when optically scanning using a flying spot scanner or the like.

Flying spot scanners (hereinafter referred to as F1a) were originally used for slide imaging, but have recently come to be widely used as optical scanning devices such as pattern recognition devices.

As the amount of information handled in pattern recognition increases1 or processing speed increases, the area to be optically scanned also becomes larger.
As the size of the scanning section increases, it is not easy to maintain uniform scanning characteristics for all the scanning sections. Basically, the scanning lines should be spaced at equal intervals over the entire range, but a drift phenomenon occurs in which scanning becomes denser or coarser in one area.
This drift is caused by changes over time in the components of the control circuit of the scanning unit.
It is also affected by temperature changes.

An object of the present invention is to provide an optical scanning position correction device that can solve the above-mentioned problems.

In order to achieve the above object, an optical scanning position correction device according to the present invention is an optical scanning reading device that uses a flying spot scanner to scan a specified arbitrary position of a recognition target. A reference plate with a position mark is placed on the scanning plane perpendicular to all scanning lines, scanned by a flying spot scanner, and the signal affected by the reference plate is processed to generate regression between the scanning position and the scanning line. The straight line is set and memorized, and the subsequent designation of the scanning position is uniquely determined by referring to the memorized memory.

That is, the present invention arranges a reference plate having marks at a plurality of positions set in advance so as to be located in the entire scanning line area of an optical scanning device, scans the reference plate, and calculates the measurement results of the positions of the marks. Based on the principle of the least squares method, an attempt is made to minimize the influence of drift errors of the optical scanning device by setting optimal linear characteristics such that the error at each position is minimized.

By making this kind of correction, 1 drift can be reduced.
Drift correction can be easily performed without complicated position correction for each position.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an optical scanning position correction device according to the present invention.

FIG. 2 shows a plan view of the reference plate on which marks are printed.

At equal intervals in advance as shown in Figure 2! -riM 1M
*・・・・・・・・・・・・・・・・・・Mn#L printed plate 1 is sequentially scanned by FSS 2 controlled by X color/color 3. The reflected light is photoelectrically converted by a photomultiglayer 4 and quantized by an A/D converter 5. The center position of the quantized mark pattern is determined by the mark detection circuit 6, and the counter value of the F88X counter 3 whose center position is detected is stored in the memory 7.

The above operation is repeated N times for the marks, all marks are scanned, and when detected, each measured value is read out from the memory 7, and the correlation between each mark is calculated by the calculator 8.

This calculation is as follows.

This becomes the slope of the regression line for each measurement data.

Figure 3 shows the regression line.

Once the regression line is determined in this way, when an arbitrary position X is designated by the scanning position designation signal 10 shown in FIG. The X counter value f can be calculated by the calculator 9.0f-a(x-x)+7 As explained above, according to the present invention, there is no possibility of drift of the optical scanning unit or deviation of the FSS position. By scanning the marks on the reference plate at any time and performing the above operations, a regression line can be easily obtained. Thereafter, by determining the scanning position based on this, scanning fluctuations can be easily corrected.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing an embodiment of a correction device for an optical scanning device embodying the present invention, Figure 2 is a plan view of a reference plate on which a plurality of marks are printed, which is part of the correction device, and Figure 3 The figure shows an example in which marks and their detection counter values are plotted and a regression line is obtained from the measurement results. 1... Reference plate 2 on which marks are printed - Flying spot scanner 3... X counter 4... Photomultiplier 5 - A/l'D converter 6... Mark detection circuit 7...・Memory 8...Arithmetic unit 9...Arithmetic unit 10...Scanning position designation signal Patent applicant NEC Corporation

Claims (1)

[Claims] In an optical scanning reader that scans a specified arbitrary position of a recognition target using a flying spot scanner,
Multiple preset digits f#,! - Place a reference plate with an angle on the scanning plane perpendicular to all scanning lines, scan it with a flying spot scanner, process the signal affected by the reference plate, and draw a regression line between the scanning position and the scanning line. 9. An optical scanning position correcting device characterized in that the optical scanning position correction device is configured to set and store the following information, and to uniquely determine the subsequent designation of the scanning position by referring to the storage.