JPS63316276A - Recognizing device - Google Patents

Abstract

PURPOSE:To inspect line-shaped blurring defect in a printing without the influence of a printing edge by generating a dictionary pattern to use the preparing data of a recognizing subject and to instruct the position of a density measuring, using it and executing the density measuring. CONSTITUTION:A test pattern printed by a dot printer 1 is photographed by an image pick-up device 3, an analog image signal to have variable density is obtained, changed to a digital image signal by an image input circuit and stored to a frame memory 5 as an inspecting subject pattern. In a dictionary generating circuit 9, from a character pattern to correspond to the test pattern, the density is read, a reading point instructing pattern is prepared and a pattern matching circuit 6 uses a dictionary pattern 8 prepared in the circuit 9, scansin the memory 5 and executed a position determining by a pattern matching. A density measuring circuit 7, in a position outputted from the circuit 6, based on the pattern 8, adds density to X axis and Y axis directions and counts the number of a photographing bit. Thus, the pattern of a density photographing value is easily obtained.

Description

[Detailed description of the invention] [) Already required] An image to be recognized is stored in a frame memory as a digital image, and a dictionary pattern for instructing the position of density measurement is created using the created data for the recognition target. This recognition device inspects images by measuring the image density in a frame memory using dictionary patterns. As a result, in dot printing, a dictionary pattern is created to indicate the dot position using the pattern data of the character generator for printer printing, and by excluding the peripheral area of the print where the print density is unstable from the instructions, it is possible to The measurement is performed at a certain density position to reliably detect linear blurring defects within the print as defects.

[Industrial application field]

The present invention relates to a recognition device that can reliably detect a defect to be recognized as a defect.

[Conventional technology]

Conventionally, one of the defects in the print quality of dot blinks is a fluffy blur defect, and it is necessary to detect this defect in a printer print inspection or the like. FIG. 7 is a diagram showing normal printing of a square pattern, and FIG. 8 is a diagram showing a linear deviation defect in the same square pattern. In FIG. 8, the linear blur defect is formed in the form of a white line as a portion that is not printed in the horizontal direction.

This is because one or more of the dot pins constituting the printer head cause a protrusion failure.

To detect this linear misalignment defect, as shown in Figure 8, print density values are added in the X-axis or Y-axis direction, and the maximum value (Max) and minimum value (Min) of each added value are calculated. When the value of this difference (Max-Min) is smaller than a predetermined reference value (S,) (Max-Min<S,), it is judged as good, and when it is greater than or equal to it (Max-1vlin≧SL), it is judged as bad. Was.

[Problem that the invention seeks to solve]

In the conventional detection method described above, for example, as shown in FIG.
If there is originally a difference in density between the printed edges and the inside of the printed square pattern, the product may be mistakenly determined to be defective even though it is a good product. Furthermore, when dot printing is viewed under magnification, the density differs between the dot center and its periphery, as shown in Figure 9, and in image processing for detection, it is detected at a finer reading pixel interval than the printed dot interval. When doing so, a difference occurred in the concentration values, and correct concentration determination could not be made. Furthermore, if the reading pixel interval is made finer and the addition process is performed for all pixels, there are problems such as the need for a long time.

The present invention has been made to solve the above-mentioned problems, and is capable of reliably detecting linear blurring defects in printed characters, reducing processing time, and enabling high-speed detection. Our goal is to provide equipment.

[Means for solving problems]

FIG. 1 is an overall configuration diagram of a recognition device according to the present invention.

In FIG. 1, 1 is a test pattern 2 based on a character generator 10 that generates test baton data.
3 is an imaging device that images the test pattern 2, 4 is an image input circuit, 5 is a frame memory, 6 is a pattern matching circuit, 7 is a density measurement circuit,
Reference numeral 9 denotes a dictionary creation circuit that creates dictionary patterns 8 from the character generator 10. The dictionary pattern 8 created by the dictionary creation circuit 9 is sent to the pattern matching circuit 6.
is output to the concentration measurement circuit 7.

[For production]

An analog image signal obtained by imaging the test pattern 2 with the imaging device 3 during print inspection is converted into a digital image signal by the image input circuit 4 and then stored in the frame memory 5. A dictionary creation circuit 9 has previously created a dictionary 8 which indicates an appropriate measurement density position using the character generator 10 which is the creation data of the test pattern 2. Next, the pattern position in the frame memory 5 is determined by the turn matching circuit 6, and then the temperature measurement circuit 7 performs measurement using the dictionary pattern 8. Dictionary pattern 8 indicates the dot position during actual dot printing and excludes the printed periphery where the density is unstable, making it possible to measure the density properly and eliminate defects such as linear blurring in the print. Detected.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail.

FIG. 1 is an overall configuration diagram of a recognition device according to the present invention.

In the present invention, first, the character generator 10 stores test pattern data in a ROM or the like during a print inspection.
A print test pattern 2 is created by the dot printer 1 based on the above. This print test pattern 2 is imaged by an imaging device 3 constituted by a CCD or the like, and the unevenness in light quantity is corrected and obtained as an analog image signal. This analog image signal is converted into a digital image signal in the image input circuit 4 and stored in the frame memory 5 as a density value. On the other hand, a density reading position instruction pattern corresponding to the character pattern is created in the dictionary creation circuit 9 based on the character generator IO, and is stored as a dictionary pattern 8. Then, the pattern matching circuit 6 scans the dictionary pattern 8 created by the dictionary creation circuit 9 in the frame memory 5, detects the position of the pattern to be inspected, and outputs the position to the density measurement circuit 7. Concentration measurement circuit 7 uses dictionary pattern 8
is used to perform density addition in the Y-axis and Y-axis directions, inspect for linear blurring defects in printing based on the magnitude of the difference between the maximum value and the minimum value of the added value, and output the determination result.

Next, the operation of the above embodiment will be explained using the operation flowchart of FIG. 2 and FIGS. 3 to 6.

First, test pattern 2 printed by dot printer 1
is acquired by the imaging device 3 as a grayscale value as an analog image signal. Furthermore, it is converted into a digital image signal by the image input circuit 4 and stored in the frame memory 5 as a pattern to be inspected. If the pattern to be inspected is a rectangular pattern, as shown in FIG. 3, areas of high density (black circles) centered on printed dots are arranged in the Y-axis direction. Further, the dictionary creation circuit 9 creates a density reading point instruction pattern from the character pattern of the character generator 10 corresponding to the test data. In the case of a rectangular pattern, this instruction pattern is created so that the center of the print dot excluding the periphery of the print pattern is the position of the reading pixel (small white circle), as shown in Figure 4. Figure 2 s 1). Next, the pattern matching circuit 6 matches the dictionary pattern 8 created in the dictionary creation circuit 9.
The inside of the frame memory 5 is scanned using the , and positioning is performed by pattern matching (as shown in FIG. 2, 32).

The density measurement circuit 7 performs density addition in the Y-axis and Y-axis directions based on the dictionary pattern 8 created in the dictionary creation circuit 9 at the pattern position output from the pattern matching circuit 6, and counts the density projection value. At the same time, the number of projected bits is counted. That is, with positioning performed by pattern matching, the density of the pattern to be inspected is read at the reading pixel position indicated by the density reading point instruction pattern and counted on the Y-axis and Y-axis, as shown in FIG.
A pattern of density projection values f(y) as shown in al is formed. In addition, with pattern matching performed in the same manner, the number of cylinders of read pixels of the density reading point instruction pattern is counted in the Y-axis and Y-axis directions, and the projected bit number n ( y) is formed (see FIG. 2, 83).Next, the density measurement circuit 7 calculates the normalized line density (f(y)) from the density projection value f(y) and the projection bit number n(y). /n(y)) (see Figure 2, 34).For example, if the test pattern is an upward arrow as shown in Figure 6 (al), the density reading point indication pattern is calculated as shown in Figure 6 (al). bl, and the density projection value pattern and projection bit number pattern have different densities depending on the position, as shown in FIG. 6fc).

However, as shown in Figure 6 (d+), if normalized line density is used, a pattern with no variation due to position will be formed.In other words, the density addition will be normalized without being affected by the test pattern. Next, the density measurement circuit 8 calculates the maximum value (Max) and minimum value (Mi) from the normalized line density.
n) and set this value to a predetermined standard value (SL).
Compare with. That is, when Max-Min<St, it is determined to be good, and when Max-Min≧SL, it is determined to be defective, and the result is output (see FIG. 2, 35).

In the manner described above, linear blurring defects in printed characters can be detected. At this time, the center of the printed dot of the pattern to be inspected is indicated by the density reading point instruction pattern and the density is measured, making accurate density measurement possible.
This eliminates the influence of density differences in the printed edge portions of the test pattern, and also shortens the time required for density addition processing.

Note that in the above embodiment, the dictionary pattern is created using a character generator for printer printing, but it is sufficient to create a pattern that instructs the density measurement position using at least the created data of the recognition target. .

〔Effect of the invention〕

According to the present invention, a dictionary pattern for instructing the density measurement position is created using the created data of the recognition target, and the density measurement is performed using this dictionary pattern, so that it is not affected by print edges. Linear blurring defects in print can be inspected using appropriate density measurement values, and processing time is also shortened.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a recognition device according to the present invention, Fig. 2 is an operation flowchart according to an embodiment of the present invention, Fig. 3 is a diagram showing a pattern to be inspected, and Fig. 4 is a diagram showing a density reading point instruction pattern. , FIGS. 5(a) to (C) are diagrams illustrating an example of concentration measurement according to an embodiment of the present invention, FIGS. 6(a) to (d) are diagrams illustrating concentration measurement in the case of an arrow, and FIG. The figure shows normal printing in a square pattern, FIG. 8 shows a linear blur defect in a square pattern, and FIG. 9 is an enlarged view of dot printing. DESCRIPTION OF SYMBOLS 1... Dot printer, 2... Test pattern, 3... Imaging device, 4... Image input circuit, 5... Frame memory, 6... Pattern matching circuit, 7... Density measurement Circuit, 8...Dictionary pattern, 9...Dictionary creation circuit, 10...Character gephrator.

Claims (1)

[Scope of Claims] (i) An imaging device (3) that inputs an image to be recognized, and an image input circuit (4) that converts an analog image signal output from the imaging device (3) into a digital image signal. , a frame memory (5) for storing the digital image signal output from the image input circuit (4), and a pattern matching circuit (5) for positioning the image in the frame memory (5) using the dictionary pattern (8). 6) and a density measurement circuit (7) that measures the image density in the frame memory (5), the recognition device comprises: a density measurement circuit (7) that measures the image density in the frame memory (5); 1. A recognition device comprising: a dictionary creation circuit (9) that creates a pattern for instructing the image; and outputs the pattern of the dictionary creation circuit (9) to the density measurement circuit (7) to measure image density. (ii) The recognition target creation data is pattern data of a character generator (10) for printer printing, and the dictionary pattern (8) indicates actual printed dot positions based on the character generator (10). A recognition device according to claim 1, characterized in that: (iii) The recognition device according to claim 2, characterized in that the dictionary pattern (8) excludes a printed peripheral area where the density value is unstable.