JPS60235281A - Pattern checking device - Google Patents

Abstract

PURPOSE:To generate automatically a dictionary by using a linear irradiating device, which irradiates light to a pattern to be recognized from an oblique direction, to detect this pattern placed at a specific height of an object to be tested, and transferring this pattern information to a dictionary memory. CONSTITUTION:In a pattern checking device having a pattern matching circuit, an image pickup area of an object 15 to be tested is irradiated from the oblique direction by a linear irradiating device and is detected by an optical sensor 4. The optical sensor 4 picks up selectively only pattern information of a desired area different in height from the other areas. Only this pattern information is cut out and is transferred to a dictionary transfer memory 9 to generate the dictionary.

Description

[Detailed description of the invention] (1) Technical field of the invention The present invention relates to a pattern inspection device. especially.

The present invention relates to an improvement for automating the first step of dictionary creation in a pattern inspection apparatus using a pattern matching circuit when a region of a test object where a recognized pattern exists has a height difference from other regions.

(2) Background of the Technology An example of a block diagram of a pattern inspection apparatus using a pattern matching circuit in the prior art is shown in FIG. In the figure, l is a stage, which is sent in the left-right direction in the figure by a stage controller 3 controlled by a control system 2. Then, the test object 11 having the pattern to be recognized is placed thereon. 4 is an optical sensor, for example a CCD line sensor imaging device. In this example, the fixed i! At the same time, patterns existing in a line in the direction perpendicular to the feeding direction (the direction indicated by the depth in the figure) are picked up simultaneously. 5 is a signal conversion amplification circuit that can be installed as necessary, such as a TV driver. 6 is an A/D conversion circuit. 7 is a frame memory, and an optical sensor 4
Image signal picked up by (maximum stage 1
image signals covering the entire area) are accommodated. 8 is T
It is a V monitor, which displays an image based on the image signal stored in the frame memory 7, and can selectively cut out a partial area of the image and transfer it to the dictionary memory 9 based on a command from the control system 2. It is configured as follows.

10 is a pattern matching circuit which compares a specific part of the image signal stored in the frame memory 7 with the corresponding image signal stored in the dictionary memory 9, and performs -1- specified identification. This is a circuit for determining the identity between an image of y and a corresponding image stored in the dictionary memory 9.

In using the pattern inspection apparatus described in 1-, first, the standard pattern of the standard test object is picked up by the optical sensor 4, stored in the frame memory 7, displayed on the TV monitor 8, The frame image displayed on the TV monitor 8 (the same image stored in the frame memory 7 ) is selectively cut out and transferred to the dictionary memory 9 to create a dictionary. In this way, after a dictionary storing desired pattern information among the standard patterns of the standard test object is created, the test object 11 is placed on the stage L, and the stage controller 3 is used to move it left and right in the figure. [7] picks up the pattern of the test object 11 and stores it in the frame memory 7, and uses the pattern matching circuit to match the standard pattern stored in the dictionary memory 9. Each image is compared with a corresponding image among the images stored in the frame memory 7, and if there is an image that does not match, a mismatch signal is output.

(3) Prior art and problem 1 - As mentioned above, in the prior art pattern inspection device that uses a pattern matching circuit, image identity determination is automatically made; The process of storing a specific pattern in the dictionary memory, that is, the process of creating a dictionary, is done artificially, as described in , and is complicated and requires a considerable amount of work. In a pattern inspection device that uses a pattern matching circuit, the possibility of incorrect input cannot be denied.
There was a desire to automate the dictionary creation process.

(4) 1-1 of the invention The object of the present invention is to provide a system with a function to automatically create a dictionary when the area of the test object where the recognized sophistication pattern exists has a difference in height from other areas. An object of the present invention is to provide a pattern inspection device using a pattern matching circuit.

(5) Configuration of the Invention The configuration of the present invention includes an imaging system, a frame memory that stores pattern information obtained by the imaging system, a dictionary memory that stores standard patterns, and a dictionary memory that stores standard patterns. a pattern matching circuit that compares each of the standard patterns with a corresponding pattern among the patterns stored in the frame memory to determine identity;
In a pattern inspection apparatus having a control device that executes the process over time, for the area imaged by the imaging system, d is the linear irradiation light width, and h is the width of the imaged area from the surface of the test object. protruding height.

a line-shaped irradiation device that irradiates the surface of the test object from a direction inclined from the imaging direction by an angle represented by , and all pattern information of the area irradiated by the line-shaped irradiation device and imaged by the imaging system is stored in the frame memory. and a means for selectively extracting pattern information from the pattern information and transferring it to the dictionary memory.

(6) Embodiments of the Invention Hereinafter, a pattern inspection apparatus according to an embodiment of the present invention will be further described with reference to the drawings.

As an example, a pattern inspection device for determining whether the arrangement of each key top on a keyboard 1- is correct or not will be described.

In the drawing shown in FIG. 2, 12 is a keyboard, and 13 is a key top that protrudes from the surface of the keyboard 12. As shown in FIG. 14
is a line-shaped irradiation device, which is provided at an angle of θ from the imaging direction of an optical sensor 4 such as a television imaging device constituting the imaging system.

By the way, the optical sensor 4 of the TV IJll imaging system uses an objective lens with an aperture of several centimeters for the purpose of condensing light, but the sensor body is a semiconductor mounted at the imaging position of the lens system. Because it is composed of a light-receiving element, etc.
It is only sensitive to light that enters the lens from a direction perpendicular to the lens and has an extremely narrow width of about several tens of microns. Therefore, the reflected light A from the surface of the key top 13 is transmitted to the optical sensor 4.
When the irradiation light is irradiated so that it can be imaged, the width of the irradiation light emitted by the line-shaped irradiation device 14 is d, and the key top 1
When h is the height of 3, the reflected light from the area that does not satisfy the condition h tan θ = 0 is detected by the optical sensor 4.
Therefore, the image will not be captured. That is, the reflected light from the region satisfying the condition h tan θ−aSO is shown by B in the figure and is not imaged by the optical sensor 4.

As a result, it is possible to selectively pick up pattern information only in areas that satisfy the condition.

In other words, as written in -, Ill,! d from the imaging direction by an angle of #! Let me take it off, keyboard 1
When irradiating a test object having a height difference as shown in 2, the key top 13, that is, the area whose height differs by h from the imaged area, i.e. the surface of the keyboard 12, is not imaged, and only the key top 13 is selectively imaged. Imaged.

For clarity, refer to Figure 3. In other words, in the plan view shown in Figure 3, the areas indicated by C and C' are irradiated, but as mentioned above, the optical Since the sensor 4 only senses light from an extremely narrow width area, it senses the light in the area marked C in the figure, but cannot sense the light in the area marked C゛.As a result, the key top Only the pattern on the surface of the keyboard 13 is selectively imaged, and the pattern on the surface of the keyboard 12 is not imaged.

In addition, the formula 1- is h>-! A-cot.

It can be transformed into This means that key top 13
This shows that even if the height h varies within this range, the selective imaging described above is sufficiently possible.

(,j%i4) When using visible light, in order to remove dark signals, the input signal of the optical sensor 4 is sliced with an appropriate value and converted into a binary signal, -1-
It is necessary to take appropriate measures to take images while placing the above-mentioned imaging system in a dark box to prevent the incidence of undesired light.

Refer to FIG. 4 A line-shaped irradiation device 14 that satisfies the conditions described with reference to FIGS. 2 and 3 is added to a pattern detection device according to the prior art as shown.

(When using visible light as the irradiation light, it is necessary to place the imaging unit in a dark box or the like.

In the figure, l is a stage, which is sent in the left-right direction in the figure by a stage controller i roller 3 controlled by a control system 2. Then, a standard test object 15 having a standard pattern is placed on the -1-. 4 is an optical sensor, for example a CCD line sensor imaging device. In this example, patterns that are fixed opposite to the stage l and that exist in a line in a direction perpendicular to the feeding direction (the direction indicated by the depth in the figure) are simultaneously pick-amplified. Reference numeral 5 denotes a signal conversion and amplification circuit provided as necessary, for example, in the TV driver 8. 6 is A/
This is a D conversion circuit. A frame memory 7 stores an image signal picked up by the optical sensor 4 (image signal covering the entire area of the largest stage l). When irradiating with a line-shaped irradiation device 14 that satisfies the above conditions, the optical sensor 4 selectively transmits only the pattern information of the desired area (an area whose height differs from other areas by h), that is, only the key tops. picked up,
Other areas (keyboard surface) are not imaged (recognized as black areas), so! 1. In the dictionary creation step, pattern information of a desired area is selectively input to the frame memory 7 (other areas are input as black areas). Therefore,
Only this pattern information is cut out and transferred to the dictionary memory 9 to create a dictionary.

The following steps 1- are automatically executed by the control system 2.

The pattern recognition operation of determining whether the pattern of an unspecified test object is correct or incorrect using a dictionary storing standard patterns is exactly the same as in the prior art.

As explained above, the pattern inspection device according to this embodiment can select and pick up pattern information in an area of a specific height from other areas (other areas are black, ignoring any pattern information). ) Therefore, if there is a difference in height between the recognized area of the test object and other areas, and only the patterns that exist in the area of that specific height are recognized and transferred to the dictionary. If it is OK, the dictionary creation step is automatically executed.

(7) Effects of the Invention As explained in 1-1, according to the present invention, when the area where the recognized pattern of the test object exists has an i-L level difference from other areas, It is possible to provide a pattern inspection device that uses a pattern matching circuit and is provided with a pattern matching function.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a pattern inspection apparatus using a conventional pattern matching circuit. Figure 2,
Figure i3 is a diagram illustrating the principle of selectively picking up pattern information only from a region at a specific height of an irradiated object using a line-shaped irradiation device according to the gist of Kibatsu 1N+. FIG. 4 is a block diagram of a pattern inspection apparatus according to an embodiment of the present invention.

Claims (1)

[Claims] An imaging system, a frame memory that stores pattern information obtained by the imaging system, a dictionary memory that stores standard patterns, and each of the standard patterns stored in the dictionary memory. In a pattern inspection device having a pattern matching circuit that compares a corresponding pattern among the frames stored in the frame memory and determines the frequency and frequency, and a control device that executes the process over time. , with respect to the area imaged by the imaging system. However, d is the linear irradiation light width, and h is the height at which the imaged area protrudes from the surface of the test object. A line-shaped irradiation device that irradiates the surface of the test object from a direction tilted from the imaging direction by an angle represented by /-f stage for selectively cutting out pattern information stored in the memory and transferring it to the dictionary memory.