JPS63282605A - Apparatus for detecting position - Google Patents

Abstract

PURPOSE:To make it possible to detect a position with high accuracy and to align positions with a crossed table driven, by detecting a plurality of edges by application of horizontal and vertical projection integrations to picture data picked up by a TV camera, and by averaging same. CONSTITUTION:A TV camera 4 picks up a close-contact type image sensor as an object 1 and makes it binary-coded, thus obtaining right and left pictures and storing same in a memory. When the whole of the pictures are subjected to projection integration in the vertical direction, subsequently, a sharp fall is found in an end part X0 of the sensor and it can be detected as an edge. When the fore end part of a left sensor is denoted by X1 and that of a right sensor by X2, therefore, the absolute value DELTAX of the difference between X1 and X2 is a positional slippage between the left and right sensors in the horizontal direction. Next, the projection integration is applied in the horizontal direction, and beltlike edges Y1, Y2...Y8 are detected thereby and averaged. The absolute value DELTAY of the difference between the left and right averaged values thus obtained is the positional slippage in the vertical direction. Accordingly, the crossed table 2 of the right sensor is driven on the basis of DELTAX and DELTAY and thereby the positional alignment thereof with a fixed stage 3 of the left sensor can be conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a position detection device that uses image processing to detect positional deviation and performs alignment.

[Conventional technology]

Conventionally, in position detection methods using image processing in position detection means, a characteristic part of the object to be detected is stored in memory as a template, and the template is used in the image data of the object to be detected. Scanning was performed sequentially from corner to corner, and the position with the highest degree of matching was taken as the detection position.

[Problem that the invention seeks to solve]

However, in this conventional template-based matching method, many similar patterns (
If multiple locations are detected, such as when
The position could not be detected accurately. Well, basically matching using templates is like W! ! Even if detection was possible, there would still be a one-pixel shift, which is a digital error, and there would be problems such as the inability to improve accuracy. Actually, in order to solve the problem of accuracy, some methods detect the edge position by projection integration of a specific edge in the image pattern after matching using Tenbrae F, and improve the position detection accuracy. Even in this case, accuracy less than the digital error cannot be guaranteed.

The present invention has been made in view of these problems, and its purpose is to detect a target object even if the pattern contains many similarities in a position detection device using image processing. The object of the present invention is to provide a highly accurate position detection device with less than a digital error by detecting a plurality of edges.

[Means for solving problems]

The position detection device of the present invention includes a binarization means that captures a pattern of an object whose positional shift is to be detected using a TV camera and binarizes the image signal using a threshold value, and stores the binarized signal in a memory. means for projecting and integrating the image data stored in the memory in horizontal and vertical directions; position detecting means for calculating a positional shift based on the projected and integrated data; It is characterized by comprising a drive circuit that drives the orthogonal table based on the data obtained by the detection means.

[Effect]

To explain the operation of the position detection Ha of the present invention, the TV
Based on the integral data obtained by the horizontal and vertical projection integration means for the image data captured by the camera, the position detection means detects multiple edges, and by averaging them, the position can be determined with accuracy less than a digital error. Since it can be detected, the orthogonal table can be aligned with high precision by the drive circuit.

〔Example〕

Therefore, details of the position detection device of the present invention will be explained below based on illustrated embodiments. FIG. 1 is a block diagram showing the configuration of the position detection device of the present invention, in which 1 is the object, 2 is the orthogonal table, 3 is the fixed stage, 4 is the TV camera, and 5 is the 2
digitization means; 6 is image data storage means; 7 is horizontal/vertical integration means; 8 is position detection means; 9 is driving means. Figure 2 shows a close-contact image sensor, which is the object used in the present invention.
It is a binary image when two are lined up, and it contains many similar patterns, and the left and right sensors are symmetrical.

By detecting the position of the two left and right contact image sensors 10 and 11, aligning them, and connecting them, a longer 1!7@ type image sensor (hereinafter referred to as sensor) is created.
can be made. Note that 12 represents a light receiving section of the sensor. Next, the method of position detection will be explained using FIGS. 3 to 5. FIG. 3 is a circuit block diagram of the horizontal and vertical projection integration means.
It manages the vertical address circuit 14, horizontal address circuit 15, and counter 17. The address circuit at 14.15 can increase or decrease the address value by hardware using the control signal 130, and outputs image data from the memory 16 based on the address generated at 14.15.
17 counters can count (projection integral) the white (digitally 1) of the image.

By using the 130 control signal, the address generation pattern of the address circuit in 14.15 can be changed freely, such as raising or lowering only the horizontal address or raising or lowering only the vertical address.By combining these, you can create any horizontal or vertical address section. You can perform horizontal and vertical projection integration within. Furthermore, the projection integral data is sent to the CPU
18. FIG. 4 shows how the end portion of the sensor is projected and integrated using the circuit shown in FIG. FIG. 4(a) shows the result of horizontal projection integration of the edge of the dense image sensor shown in FIG. 4(C).

A contact image sensor has a strip in the horizontal direction, and the projection result also has a steep increase/decrease portion indicated by Y, ~Y, corresponding to the edge of the strip. The edge position of the sensor can be detected.As shown in Fig. 4(b), the result of vertical projection integration is as follows:
There are sudden and drop-offs that can be detected as edges. In the matching method using the step rate, image flickering, which is a problem in binarized image processing, cannot be ignored, but in projection integration, since pixels are integrated, it is possible to absorb a considerable amount of image flickering, improving the accuracy of edge detection. can be done.

Next, the processing procedure of the position detection device will be explained based on the flowchart shown in FIG.

After capturing the image shown in Figure 2, the entire image is projected and integrated in the vertical direction (19). As shown in Figure 4 (b), the tip of the sensor can be detected, and the positions of the left and right sensors are I understand the relationship. (The tip of the left sensor is Xl and the tip of the right sensor is X2.) By this,
You can now process only the left sensor and only the right sensor, and if you perform projection integration in the horizontal direction for each of the left and right sensors (20>, m4, as shown in Figure (a), multiple edges (left Sensor Y++Y1...
...8 Y+a, right sensor Y,,Y.

, . . . 8 lines of Yes) can be detected. (
21) Calculating the horizontal positional deviation ΔX between the left and right sensors based on these data, it is given by ΔX=IX1-X2+ (1),
Calculating the positional deviation ΔY between the left and right sensors in the vertical direction, ΔY=+(Yz+...+Y, , )/8-(Y, ,
+...10 Y, , ') /8 1
It is given by (2). , (22) In this case, ΔY
When calculating, since the average is performed using eight edge data, the accuracy can be expected to be 1/8 of one pixel, which is a digital error, and high-precision position detection is possible. Next, this detected positional deviation amount ΔX1ΔY is converted into pulse data for driving the table, and the orthogonal table (first
Figure 3) is driven and aligned with respect to the fixed stage of the left sensor (Figure 1, Figure 3).

〔Effect of the invention〕

As described above, according to the present invention, even if the position detection target object includes many similarities, the position can be detected, and the position data can be calculated by detecting a plurality of edge data. Therefore, highly accurate position detection can be performed with less than digital error.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for clearly showing the configuration of the position detection HH of the present invention. FIG. 2 is a diagram showing a close-contact image sensor, which is the object used in the present invention, captured by a camera. FIG. 3 is a circuit block diagram of horizontal and vertical projection integration means. FIGS. 4(a) and 4(b) are diagrams showing the results of horizontal and vertical projection integration of the contact type image sensor used in the present invention. FIG. 4(C) is a diagram showing a close-contact type image sensor. FIG. 5 is a flowchart showing the operation of the position detection device of the present invention. 1...Object 2...Orthogonal table 3...Fixed stage 4...TV camera 5...Binarization means 6... ...Image data storage means 7...Horizontal and vertical integration means 8...Position detection means 9...Drive means to, tt...Dense tffi image Se/Ser 1
2... Light receiving section 13... Control signal generation circuit 14... Vertical address generation circuit 15...
・Horizontal address generation circuit 16...Memory 17...Counter 18...CPU 19-23...Flowchart step 24.
...Camera imaging area and above Applicant Seiko Epson Co., Ltd. Agent Patent attorney Tsutomu Mogami and 1 other person 1 figure ¥2 Fast-talking 3 Fast-talking Doozu

Claims (1)

[Claims] (1) The pattern of the object whose positional deviation is to be detected is
A binarization means that binarizes the image signal captured by the camera using a threshold value, an image data storage means that stores the binarized signal in a memory, and a horizontal and vertical It consists of a means for projecting and integrating in a direction, a position detecting means for calculating a positional shift based on the projected and integrated data, and a driving means for driving an orthogonal table based on the data obtained by the position detecting means. A position detection device characterized by: