JPH0230065B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for inspecting the quality of a pattern, and more particularly to a method and apparatus for automatically inspecting a pattern to be inspected that is composed of a plurality of characters and symbols arranged in a predetermined order. It is something.

BACKGROUND OF THE INVENTION The act of attaching a specific display pattern to a product or its accessories in order to indicate the type of product or its manufacturing record is often practiced in the field of manufacturing various electronic components such as semiconductor products.
These display patterns are usually stamped on the surface of the product or its accessories by an automatic marking device, and in that case, there are no problems such as leakage, bleeding, fading, double printing, ink stains, skewing, etc. This may result in defects such as Therefore, if the displayed content has a particularly important meaning in terms of product performance, limited use, etc., it is necessary to test the quality of the display pattern on all products that have passed through the automatic marking device. Currently, inspection of the quality of these patterns is performed with the naked eye, and there is a strong desire for automation in order to save manpower from the monotonous inspection work for a large number of inspection objects.

One of the conventional methods proposed for automatic pass/fail inspection of such patterns is to prepare negative standard patterns with the maximum and minimum width dimensions allowable for the pattern to be inspected. The image of the pattern is superimposed on these standard patterns to determine whether the pattern to be inspected is within tolerance (Japanese Patent Laid-Open No. 49-29533).

However, according to the above-mentioned conventional method, the difference between the existence of an overall excess or deficiency in the line width of characters or symbols constituting a display pattern and the existence of serious defects concentrated in a certain character or symbol part can be detected. It is difficult to distinguish and detect defects, and in order to avoid overlooking the latter defects, it is necessary to set strict judgment criteria that only accepts cases where the inspected pattern almost completely matches the standard pattern. . For this reason, a problem arises in that even a good pattern that can be correctly read with the naked eye has a high probability of being judged as defective by automatic inspection. Furthermore, according to the above conventional method,
Since the overall image of the inspected pattern is compared with the standard pattern to determine pass/fail, it is necessary to prepare a unique standard pattern depending on the type of inspection target.
There is a problem in that it takes time to create and partially modify.

The present invention provides a novel automatic pattern pass/fail judgment that can automatically pass/fail test patterns made up of characters and symbols using judgment criteria close to those of the naked eye, and that can easily change the standard pattern according to the type of inspection target. An object of the present invention is to provide a method and apparatus.

In order to achieve the above object, in the present invention, a display pattern stamp used in a specific industrial or commercial field is based on a set of printed characters, and when viewed character by character, the same characters are the same. Focusing on the shape, letters or symbols (hereinafter referred to as
The principle is to set a well-prepared inspection standard for each character (simply referred to as a character symbol), and to accurately determine pass/fail by comparing the pattern to be inspected with the above inspection standard for each character symbol.

According to the present invention, as data corresponding to the standard pattern to be compared with the pattern to be inspected, in addition to the data indicating the above-mentioned inspection criteria prepared for each character type, data indicating the character arrangement in the pattern to be inspected is used. use Character arrangement data includes, for example, a character type table that stores data indicating the types of character symbols according to the order in which the character symbols are arranged in a pattern, and data that indicates the location of each character symbol on the video. Prepare in the form of a position table. To inspect a pattern, first, an image of the pattern to be inspected is captured into an image memory via an imaging device, and character type data and position data for the first character to be examined are read from the character type table and position table, respectively. From the image memory, partial video data specified by the inspection standard data corresponding to the character type data is read out using the position coordinates indicated by the position data as a reference point, and the presence or absence of defects in the inspection character pattern is determined. . By sequentially inspecting all the reference positions on the image specified in the position table according to the inspection standard data associated with the character type table, it is possible to determine the presence or absence of defects in the entire pattern to be inspected. .

According to the present invention, since inspection standard data for each character is commonly used for multiple types of patterns to be inspected, when a pattern is changed, the position table and character type table that specify the arrangement of characters are simply changed. Just do it. Therefore, the automatic inspection apparatus configured according to the present invention can extremely easily change the data corresponding to the standard pattern, and can quickly handle new patterns to be inspected.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the overall configuration of a system that prints on a certain product, inspects the printing results, and sorts them according to their quality. After a display pattern is printed on the products A supplied from the product supply machine 1 by the stamping machine 2, the products A are supplied one by one to the field of view of the TV camera 4 by the individual feeding device 3. The inspection device 5 inputs the video signal 71 of the TV camera 4 in response to the output 70 of the feeding device 3, and inspects the pattern printed on the surface of the product. The inspection device 5 outputs a control signal 72 according to the quality of the pattern, determines the direction of the sorting device 6, and then gives a feed command 73 to the individual feed device 3.
As a result, the next product is supplied to the field of view of the TV camera, and the inspected products are automatically sorted to the non-defective product receiving box 8a or the defective product receiving box 8b.

The inspection device 5 includes a program-operated general-purpose data processing device (hereinafter referred to as "microcomputer" or "minicomputer"), which is connected to the operation console 8 and the above-mentioned individual feeding device 3 or sorting device 6 through interface circuits, respectively. 10 (simply referred to as a computer), a memory 30 and a video data processing circuit 40 connected to the computer 10 via a data bus 20. The computer 10 has a built-in data memory 11, and this memory 11 is allocated with a character type data storage table 11a and a position data storage table 11b for indicating the arrangement relationship of characters or symbols in a pattern to be inspected. Memory 30 is for storing inspection standard data. In this example, the memory 30 is provided as a dedicated circuit outside the computer 10 in order to read the inspection standard data to the video data processing circuit 40 at high speed, but in a system that does not require high-speed image processing, the memory 30 is The internal memory 11 may be used instead. The video data processing circuit 40 is coupled to the TV camera 4 and includes a built-in memory 42 for temporarily holding video data showing the pattern to be inspected. (The detailed structure of the video data processing circuit 40 will be explained later.) FIGS. 2 and 3 each show a character type table 11a.
An example of the basic configuration of the position table 11b is shown below.
The character type table 11a stores data K ₁ to _{K i} indicating the types of i character symbols forming the pattern to be inspected displayed on the surface of the product in the order of arrangement, and stores the characters next to the final character data K _i . Stores special data (end) indicating the end of the array. On the other hand, the position table 11b has a storage area corresponding to each character data in the character type table, and has center position coordinates (X ₁ , Y ₁ ) to (X _i , Y _i ) of each character of the pattern to be inspected. I remember.

FIG. 4 shows inspection standard data storage areas 30-1 to 30-n allocated to the memory 30. A number of data storage areas are prepared corresponding to the types of characters or symbols, and each area stores an inspection standard for each character described by a series of data as shown in FIG. 5, for example.

In the example shown in FIG. 5, the inspection criterion data consists of two data strings and a symbol "9" indicating the end of data for the character.
The meaning of the inspection criteria described in these data strings will be explained with reference to FIG.

FIG. 6 illustrates, as an example, _the inspection principle for the English letter "C" printed in black on a white background.
Y ₀ ) is the center position coordinate of the character, black circles Q ₁ to _{Q 21} are inspection points set discretely along the core of the character “C”,
White circles _P1 to _P38 indicate inspection points set around the letter "C". If the center of the letter “C” in the pattern to be inspected inputted into the TV camera is superimposed on the above (X ₀ , Y ₀ ), even if the letter “C” to be inspected is printed accurately and clearly. For example, inspection point Q ₁ ~
All the video data at the position corresponding to Q ₂₁ should be at the dark level, and all the video data at the positions corresponding to the inspection points P ₁ to _{P 38} should be at the bright level. However, if part of the core of the character to be inspected "C" is broken,
The video data becomes a bright level at any of the inspection points Q ₁ to Q ₂₁ . Conversely, if the line of the character to be inspected becomes abnormally thick or if ink protrudes around the line core, the video data at inspection points P ₁ to _{P 38} will show a dark level. Therefore, the black circle Q ₁ in the input image
~ Inspect the part of the video corresponding to Q ₂₁ and count the parts that are at a bright level, examine the parts corresponding to white circles P ₁ to _{P 38} and count the parts that are at a dark level, and then Letter “C” for each of the two counts.
By comparing the characters with a preset threshold value, if either value exceeds the threshold value, it can be determined that the character is a defective character.

The inspection standard data shown in FIG.
is white), the second data n ₁ and n ₂ are the number of inspection points that follow, and the third and subsequent data are data indicating the coordinates of the inspection points (ΔX ₁₁ , ΔY ₁₁ ) to (ΔX _1o1 , ΔY _1o1 ),
(ΔX ₂₁ , ΔY ₂₁ ) to (ΔX _2o2 , ΔY _2o2 ), and at the end of each string, the threshold number of permissible brightness/dark inversion points is shown. In this case, the first coordinate points (ΔX ₁₁ , ΔY ₁₁ ), (ΔX ₂₁ , ΔY ₂₁ ) of each string are expressed as relative values from the center coordinates (X ₀ , Y ₀ ) of each character, and the subsequent coordinate points By displaying the value relative to the preceding coordinate, all inspection points can be displayed with short data regardless of the actual position of the character in the video. Since pattern inspection accuracy varies depending on the above-mentioned inspection criteria, it is necessary to prepare inspection criteria data that has been carefully examined for each character. Since the inspection standard data once stored in the memory 30 is usually not changed, the memory 30 may be a read-only storage element. If the design of the letters changes due to a different product being used, you can simply replace it.

The center coordinates (X ₀ , Y ₀ ) of each character are given from the position table 11b, and the addresses A1 to A7 of the storage area for each inspection standard are specified by data K ₁ to _{K i} in the character type table 11a. . The data K ₁ to _{K i} may be values that directly indicate the addresses A1 to An, but
Inspection standard data storage areas 30-1 to 30-n
have the same space (N words), the character type data K ₁ to _{K i} are a series of numbers corresponding to the character types, and the addresses A1 to An are obtained by multiplying the above numbers by a constant value N. You can do it like this.
In addition, if the lengths of the storage areas 30-1, ~30-n are uneven, the character type data is used as a serial number, and the addresses A1 ~ An of the storage areas are determined using a separately prepared address conversion table. Good too.

FIG. 7 is a diagram showing an example of a more specific circuit configuration of the inspection device 5, particularly the video data processing circuit 40. In the figure, 41 is a circuit for binarizing the video signal 71 from the TV camera 4, 42 is a video memory for storing digitized video data, and 43 is a circuit for controlling the operation sequence of the video data processing circuit. Controller, 44 is a register for storing bright/dark divisions (black and white), 45 is an inspection point counter, 46 is an address calculation circuit, 47 is the number of points where the brightness is reversed (the number of defective inspection points) 48 is a register for a flag indicating the test result, and 49 is an internal data bus. The computer 10 supplies parameters and activation signals to these circuits via the data bus 20, and reads operation results from the register 48. Also, controller 4
3 outputs control signals 90a to 90n, thereby controlling the operation of each element of the video data processing circuit.

FIG. 8 shows a series of operational flows of the inspection device 5 performed under the control of the computer 10 and the controller 43. The computer 10 monitors the feed completion signal 70 from the individual feeder 3 (routine
100), when the feed completion signal 70 is input, the signal 8 instructs the binarization circuit 41 to capture video data.
Outputs 1 (routine 101). After this, calculator 1
0 clears the flag register 48 by the signal 82, sets the parameter i that addresses tables 11a and 11b to the initial value (1) (routine 102), reads the i-th data of the character type table 11a, and is sent to the address counter of the inspection standard memory 30 as address data 83 (routine 103). The calculator 10 further includes a position table 11
The i-th data (X _i , Y _i ) of b is read and sent to the address calculation circuit 46 as character center coordinate data 84 (routine 104), and an activation signal 85 is given to the controller 43. Since the operation corresponding to the routine 105 is performed under the control of the controller 23, after outputting the activation signal 85, the computer 10 receives the video data processing end signal 85' from the controller 23.

The controller 43 causes the memory 30 to perform a read operation using a control signal 90a, and increments an address counter built in the memory by one each time the read operation is performed. The first data read from the memory 30 is as explained in FIG.
This is light/dark classification data that indicates whether the normal data at the inspection point is white or black. The controller 43 sets this light/dark classification data in the register 44. memory 30
The next data read out is a value indicating the number of inspection points, and this data is set in the counter 45. Thereafter, the data successively read from the memory 30 is the coordinate data indicated in the incremental display. The controller sequentially reads these coordinate data to the address arithmetic circuit 46 and decrements the counter 45 by 1 each time. The address calculation circuit adds the read data to already stored coordinate data and successively calculates position coordinates in the video space to be inspected. These position coordinates are stored in the video memory 42.
is given as an address signal 91 to output the image data 92 of the inspection point from the image memory. The counter 47 is cleared at the time of reading the light/dark classification data, and each time a signal is input from the video memory 42, it is compared with the output of the register 44, and if they do not match, the contents are incremented by one. The controller 43 operates the address calculation circuit 46 and the counter 4 until the contents of the counter 45 become zero.
Operate 7. When the contents of counter 45 reach zero, the next data read from memory 30 represents the threshold number of acceptable defect points.
At this time, the controller 43 operates the flag register 48 and records the value of the counter 47 and the memory 3.
The data read from 0 is compared, and if the value of the counter 47 exceeds the permissible threshold, a defective flag indicating the presence of a defect is set in the flag register 48. The controller 43 continues to read the memory 30 after reading one data string.
The above-mentioned operation control is repeated until data indicating the end (indicated by reference numeral 9 in FIG. 5) appears. As a result, the pattern along the data string in the memory 30 is inspected, and when the end data is read out, the controller 43 sends a video data processing end signal 85' to the computer 10 via the data bus 20. give.

The computer 10 receives the video data processing end signal 8.
When 5' is input, the contents 82' of the flag register 48 are read (routine 106), and if the defective flag is set, a signal 72 is output to operate the sorting machine toward defective products (routine 110). Otherwise, increase the parameter i by 1 (routine
107), character type table 11 with updated parameters
The i-th data of a is read and it is determined whether this data is an end code (routine 108). If the data is not a termination code, the operating sequence returns to routine 103 and the same pass/fail test as described above is performed for the next character. If the read data from the character type table is a termination code, it means that the inspection of all the characters and symbols constituting the pattern to be inspected has been completed and there are no defective flags. Therefore, the computer outputs a control signal 72 to operate the sorting machine 6 toward non-defective products (routine 109), and outputs a command 73 to the individual feeder 3 to send out one product (routine 111). The above routine 111 is executed even after the sorting machine operates on the defective product side (routine 110), and then the computer returns to the initial operation sequence (routine 100) and expects a feeding completion signal 70 from the feeding device.

Note that the above control procedure is based on the premise that the TV camera images the display pattern to be inspected without positional deviation. However, in actual systems, due to misalignment of the stamping pattern in the stamping machine or performance limitations of the individual feeding device,
It is necessary to allow some degree of variation in the position of the display pattern input to the TV camera.

In order to deal with such variations in the position of the imaged pattern, a method of matching the pattern while gradually shifting the position of the pattern on the video, as proposed by the present inventors in Japanese Patent Application No. 55-54165, has been proposed. Just adopt it.

FIG. 13 shows the control procedure of FIG. 8 incorporating the above method, in which routines 104-106 are replaced with routines 112-117. In the control procedure shown in FIG. 13, after reading the i-th position data (X _i , Y _i ) of the position table in routine 112, the routine
In step 113, the coordinates X _i and Y _i are changed by ΔX and ΔY, respectively, and sent to the inspection processing section.
ΔX and ΔY are values for shifting the center coordinates (X _i , Y _i ) within the tolerance range (±f) of positional shift of the input pattern. Flag register 4 in routine 114
After clearing 8, the video data processing circuit 40 is activated, thereby executing the routine 115 using the changed coordinate values X and Y as center values. This routine 115 is the same as the routine 105 in FIG. 8, and if there is a defect in the character pattern, a defective flag "1" is set in the flag register 48 by this routine. When the computer 10 receives the video data processing end signal 85', it reads the contents of the flag register 48 (routine 116), and if it is defective, it proceeds to routine 117 and checks whether .DELTA.X and .DELTA.Y are the end values. If it is the end value, it means that normal character patterns were not found at all positions within the allowable positional deviation range, so the routine proceeds to routine 110 and the sorting machine is set to the defective side. routine
If ΔX and ΔY are not the end values in step 117, the process returns to routine 113 to try testing again using another position within the allowable range as the center coordinate. If the defective flag is not raised in the determination routine 116, it means that a normal character has been detected somewhere within the above-mentioned positional deviation tolerance range. Therefore the program is routine 107
After that, the control proceeds in the same manner as in FIG.

The embodiments of the inspection method of the present invention for inspecting patterns made of character symbols using inspection reference data and character arrangement data have been described above. In actual applications, when a pattern is changed, that is, a combination of characters is changed, the problem is how to easily create character arrangement data corresponding to this change.

Since the amount of character array data is generally smaller than the inspection standard data, if the types of patterns to be inspected are limited, for example, the array data of all patterns may be stored in advance in the memory of the computer 10 and then manipulated. You can choose what you need by specifying on board 8. In this case, the character arrangement data may be stored in a secondary memory attached to the computer 10, and necessary data may be read out to the main memory for use. The character array data can be stored in the memory using an input device such as a keyboard on the console 8 or a tape reader.

The character type data necessary for the embodiment of the present invention can be associated with inspection standard data prepared in advance and notified to the operator in advance, while the position data can be the design value of the pattern or It can be created by reading a photo of a standard pattern sample. A crosshair whose position can be controlled electronically is displayed superimposed on the TV camera's video monitor, and when the worker aligns it with the center of each character and presses a designated button, the position is automatically read and It may also be written to a data storage unit. Note that in many applications, position data can be shared, and it may be sufficient to replace only the character type data. In such a case, all types of position data may be prepared in advance, and necessary data may be selected from among them in correspondence with the characters of the pattern to be inspected.

A practical method for determining the center position data of each character from a sample pattern to be inspected is to use the above-mentioned inspection device, and after inputting character type data, automatically search for position data through the operation of the inspection device. It's a method. In this case, the characters are assumed to be lined up in one or more lines, and the character types are entered, for example, from the top line and in a certain direction within the line (for example, from left to right). All you need to do is to make a promise, such as using line feed codes to indicate line changes. Such preconditions are considered to hold true in most application examples.

FIG. 9 shows an example of the configuration of an inspection device that has been improved based on the above idea to automatically obtain position data and allow the operator to confirm the obtained position data. This device is obtained by adding a monitor circuit 50 and a television monitor 51 to the device shown in FIG. 1, and changing the computer program. The monitor circuit 50 receives the center position coordinates 8 of the crosshair scale from the computer 10 via the data bus 20.
6 and generates a crosshair scale on the screen, and a circuit that combines the binary video signal 87 from the video data processing device 40 with the crosshair scale and sends it to the television monitor.

Figures 10A and 10B show that each time the operator keys in a character type, the center position of the corresponding character in the pattern to be inspected is automatically determined, and the above-mentioned inspection device is operated so that the operator can confirm the result. Calculator 10
2 is a flowchart showing a control procedure. Further, FIGS. 11A to 11C are diagrams showing the position search range of the character specified by the key-in on the screen of the television monitor.

Hereinafter, the control procedure by the computer 10 will be explained in accordance with the routine numbers with reference to FIGS. 10 and 11.

201: Capture the image from the TV camera into the inspection device. The video must show a product sample with a good pattern.

202: Let o be the parameter i that indicates the order of the character arrangement in the character type table.

203: Set the character position search range to the maximum value as follows.

W ₁ ≦X≦W ₂ V ₁ ≦Y≦V ₂ As shown in FIG. 11A, this range corresponds to an area where the entire input screen is moved inward by 1/2 character from each side.

204: Waits for key-in of character type data from the operator.

205, 206: Check whether the keyed-in data is a "line feed" or not, and if it is a "line feed", change the search range as follows.

W ₁ ≦X≦W ₂ , Y _i +d<Y≦V ₂ As shown in FIG. 11B, this range is Y by a constant value d from the center position (X _i , _Y This corresponds to an area reduced in the direction, and d is a value corresponding to the maximum value of variation in the center Y coordinate between characters belonging to the same line.

207: Add 1 to parameter i.

208, 209: Check whether the keyed-in data indicates "end" and if it is data for the "end" key, write the end code in the i-th position of the character type table and create array data. is complete.

210: When neither the "line break" nor the "end" code applies, the input data (character type code) from the key is stored in the i-th position of the character type table.

211: Outputs the address corresponding to the character type code to the inspection standard memory.

212: All X and Y coordinates of the set search range are applied to the center coordinates (X ₀ , Y ₀ ) of the character, and the character pattern is judged to be good or bad according to the inspection standard data, and the position is determined to be "good". is registered in the built-in memory of the computer as a candidate point for the center coordinates (X ₀ , Y ₀ ) of the character.

213: Check the positional relationship of the candidate point data stored in the memory, and if there is a group that is connected to each other in an adjacent relationship, find the one closest to the center of gravity.
Leave the point and delete other data in the group.

214, 215: Check whether there is even one candidate point,
If it is zero, it is determined that the keyed-in character type code specifies a character that is not included in the test pattern, an error is displayed, and the process ends.

216: Select the highest priority candidate point from the candidate point data according to the following priority order determination rule. That is, the following priority ranking is determined for the two points (X, Y) (X', Y').

If |Y−Y′|>d, give priority to the smaller Y.

If |Y−Y′|≦d, the smaller X is given priority.

The procedure for selecting the highest priority candidate point is to first compare the priorities of the two candidates, keep the one with priority, and compare it with the next candidate point. When the comparison process is repeated until the last candidate point, the single coordinate that remains until the end becomes the candidate point at the highest priority position. This highest priority candidate point is set as a temporary position indicating the center of the character.

217: Output the coordinate data of the temporary position to the monitor circuit,
Generates a crosshair scale on the TV monitor.

218: Waits for key-in from the operator. The operator looks at the display on the monitor and determines whether the coordinates of the temporary position are appropriate based on the positional relationship between the crosshair scale and the actual character pattern. Based on this judgment result, the operator keys in either a correct or incorrect code.

219, 220: Determines the keyed-in data, and if an incorrect key is input, erases the temporary position candidate point data in the memory, returns to routine 214, and selects the highest priority position data from the remaining candidate points. Find.

221: In the judgment of routine 219, if a positive code is input, the temporary position data is stored in the i-th position of the position table as regular position data.

222: After one character position has been determined, the search range is changed as follows, and then routine 204
Return to

X _{i + e ≦ i} , Y _i ) by one character (e) to the right.

The method described above allows the operator to set character arrangement data in a table while checking the automatically detected character center position. If not, the monitor circuit 50 and television monitor 51 shown in FIG. 9 are unnecessary. Further, in the control flow shown in FIG. 10, the processing of routines 217, 218, 219, and 220 is not necessary, and the routine can immediately proceed from routine 216 to 221.

Next, a method for automatically creating all array data under computer control using the inspection device 5 will be described.

FIG. 12 is a flowchart of the control procedure performed by the computer 10. The operation will be explained below according to the routine numbers in the figure.

301: Capture the image from the TV camera into the inspection device.

302: Set the number indicating the character type (character type number) to 1.

303: Find the memory address of the inspection standard data corresponding to the character type number and set it in the address counter circuit of the memory 30.

304: Set the character position search range to the maximum value (Fig. 11A
), the pattern is inspected for quality at all character positions in the search range in accordance with the inspection criteria read out from the memory 30, and position data determined to be acceptable are stored as candidate points.

305: Check whether there is a candidate point in the candidate point storage area, and if there is no candidate point, proceed to routine 308.

306: Examine the relationship between position data in the candidate point storage area, and if there is a group of mutually connected candidate points, leave one point closest to the center of gravity and delete other data in the group.

307: All the candidate point data left in the candidate point storage area are registered in the position table and the character type table as array data in sequence in correspondence with the character type numbers.

308: Advance the character type number by 1.

309: Check whether the character type number exceeds the expected value, and if it does not, return to the process of 303.

310: This is the case when the character type number exceeds the expected value, the end code is stored in the character type table, and the array data creation process is ended. This method requires the use of a sufficiently good putter and strict testing standards.

The embodiments of the display pattern inspection method according to the present invention and the inspection apparatus that implements this method have been described above. In these embodiments, the character type table and position table that define the arrangement of character symbols are fixed, and are combined with general-purpose inspection standard data to automatically supply a large number of products with the same display pattern. The display pattern was inspected for quality. However, depending on the field of application of the inspection device, the arrangement of characters and symbols in the display pattern may change by one or several characters for each object, as in the case where consecutive serial numbers are included, for example. Even in such applications, if there is a certain rule for changing the character arrangement, according to the present invention, it is possible to automatically correct the character arrangement data and quickly check the quality of the display pattern. can. In many cases, the issue can be resolved simply by changing the font pattern.

Since the present invention determines whether a display pattern is good or bad for each character or symbol that is a constituent unit of the display pattern, it is also possible to weight the pattern quality judgment based on the importance of the character symbol. . For example, by storing weighting coefficient data according to the importance of each character symbol along with character type data in a character type table, the weighting coefficients for characters with poor inspection results are accumulated, and all character symbols are When the inspection is completed, the quality of the display pattern as a whole may be determined based on the cumulative value. For example, for important characters, set the coefficient to ``3'', for other characters, set the coefficient to ``1'', and if the cumulative coefficient value is ``3'' or more, it will be judged as a defective pattern. Pattern inspection can be performed that does not allow even a single character to be defective, but allows up to two defects for other characters.

In the embodiment, a memory 30 and a video data processing circuit 40 are provided outside the computer 10 that controls the overall operation of the system, and inspection standard data that provides standards for determining the quality of each character is stored in the memory. The image data processing circuit reads out the pattern at high speed and checks whether the pattern is good or bad. However, in applications where the inspection system does not particularly require high speed, the memory 30 is stored in a memory attached to the computer 10, and one part of the video data processing circuit is used.
The functions of the computer may be changed to replace the functions of the computer with the program operations of the computer. Furthermore, according to the basic idea of the present invention, which is based on the principle of inspecting the display pattern on a character or code basis, the data that provides the criteria for determining the quality of each character is limited to the format shown in the example. Two-dimensional pattern data that can be directly compared with local image data corresponding to one character of the pattern to be inspected inputted from an imaging device, as well as other formats such as standard images that do not take the form of electronic storage. Data can also serve as the above inspection criteria.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the overall configuration of an inspection system according to the present invention, and FIGS. 2, 3, and 4 are a table for storing character type data, a table for storing character position data, and an inspection system, respectively. FIG. 5 is a diagram showing an example of the structure of a table that stores standard data. FIG. 5 is a diagram showing an example of inspection standard data. FIG. , FIG. 7 is a diagram showing an example of a more detailed configuration of the inspection apparatus, particularly the video data processing circuit 40 of FIG. 1, and FIG. 8 is a flowchart showing an example of the control procedure of the inspection system according to the present invention. Fig. 9 is a diagram showing an example of a device configuration for changing character arrangement data according to the object to be inspected, and Fig. 10 A and B are controls for changing arrangement data using the apparatus shown in Fig. 9 above. A flowchart showing an example of the procedure, Figures 11A, B, and C are explanatory diagrams of the search range of character positions in the control process of Figure 10 above, and Figure 12 is a flowchart for changing character arrangement data. A control flowchart showing another embodiment, FIG. 13 is a flowchart showing a modification of FIG. 8. In FIG. 1, 1 is a product feeding machine, 2 is a display pattern stamping machine, 3 is a product individual feeding device, and 4 is a product feeding machine.
5 is a TV camera for inputting images of the display pattern; 5 is an inspection device for determining the quality of the display pattern; 6 is a sorting device for sorting products according to the results of the quality determination; 8 is a console; 10 is a calculator; 20 is a data bus, 30 is a memory for storing inspection reference data, 40 is a video data processing circuit, and 11 is a memory for storing a character type table and a position table.

Claims (1)

[Scope of Claims] 1. In a pattern inspection device for inspecting the quality of a pattern to be inspected consisting of an arrangement of a plurality of character symbols, the character symbols of a plurality of types including the character symbols of the pattern to be inspected are a first storage means for storing inspection standard data defining a plurality of inspection points on the line portion of the character symbol and its surrounding area and their states for each type; a second storage means for storing code information for identifying the type in the order in which the character symbols are arranged; and position data indicating the reference position on the video of each character symbol constituting the pattern to be inspected. a third storage means for storing in the arrangement order; a storage means for temporarily storing video data of each character symbol of the pattern to be inspected held by the object to be inspected; and from the first, second and third storage means. a determining means for determining the quality of each character symbol of the pattern to be inspected included in the video data held in the holding means, based on the inspection standard data, code information, and position data read out; The means sequentially reads from the second and third storage means a set of code information and position data corresponding to each character symbol in the order of arrangement of the character symbols constituting the pattern to be inspected, and reads the read code. Inspection standard data corresponding to the information is read from the first storage means, and based on the read position data and inspection standard data, correspondence is determined with the inspection point defined by the inspection standard data included in the image. determining whether or not the state of a specific pixel in the test conforms to the state defined by the inspection standard data, and determining whether the pattern to be inspected held by the object to be inspected is good or bad based on the determination result. A pattern quality inspection device characterized by: 2 The image data of the pattern to be inspected held in the holding means is obtained by sequentially transporting the object to be inspected by a transporting means and sequentially capturing images of the pattern to be inspected held by the transported object by an imaging means. A pattern quality inspection device according to claim 1, characterized in that: 3. The quality of the pattern as set forth in claim 2 is characterized in that, based on the determination result of the determination means, a sorting means for sorting the inspection objects sequentially conveyed by the conveyance means is controlled. Inspection equipment.