JPH0334880A - Method and apparatus for inspecting printed character - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Utilization of industry 1-1! f] The present invention inspects the quality of characters or patterns (hereinafter referred to as single ζ characters) printed on small-sized printed matter such as tablets, for example, for missing parts of characters, blurring, or inversion of characters due to incorrect printing. This invention relates to an inspection method and its device.

[Conventional technology]

1- As a method for inspecting stamped characters, an example is shown in Fig. 8 (a).
There is a first method in which the printed characters Pa and Pb of the printed matter W shown in , ) are imaged by a CI) camera, binarized, and each imaged part is inspected by the total number of dots.

As another method mentioned above, there is a second method of superimposing the target ttta images Aa, At:+ and the captured images Pa, Pb, as shown in 13/I(b).

As a third method, there is a method of comparing the total number of dots for each scanning line S, as shown in FIG.

Historically, a fourth method is to form squares (blocks) R vertically and horizontally, and detect the number of patterns occurring in each block, as shown in FIG. 3(d).

[Invention or problem to be solved]

In the first method, the circuit is complicated and it is difficult to measure the accuracy. Furthermore, the second method has the disadvantage that if there is a positional shift between the standard image and the captured image as shown in the figure, the printed characters are determined to be defective even if they are good. Furthermore, when using the third method, there is a drawback that similarly, if a positional shift occurs in the vertical direction, it is determined to be defective.

Historically, when using the fourth method, there are problems such as a complicated circuit.

In view of the above, the present invention provides an inspection method and apparatus that have an easy circuit configuration and are capable of reliably and quickly determining the quality of printed characters without being affected by positional deviation from a standard image. The purpose is to provide.

[Means for solving curricular problems]

The first invention to achieve the above object relates to a method for inspecting the number of printed characters, in which characters on printed matter are imaged with a camera, the imaged character signal is binarized, and the imaged character signal is binarized (divided by M number and L knock). to create a square wave and detect the space between characters (
The number of characters is calculated from this and compared with the standard number of characters.

The second invention similarly relates to a method for inspecting the number of printed characters, but the present invention relates to inspecting characters printed inside an outer mask, and involves dividing the inside of the outer mask into multiple sections to form small squares. ,
The character spacing is determined from the number of squares where no signal appears between images generated by binarization, the number of characters is calculated from this, and the standard number of characters is cut out.

The third invention relates to a method for inspecting the vertical and horizontal dimensions of printed characters, in which the characters on the printed matter are imaged with a camera, the imaged character No. 18 is converted to 21+i'f, the binary signal is divided by a clock to form a rectangular wave, and the character The vertical and horizontal dimensions are calculated from the vertical and horizontal rectangular wave numbers that are displayed, and compared with the standard dimension method.

The fourth invention relates to another inspection method for measuring the vertical dimension of printed characters, in which the characters printed inside the outer mask are imaged by a camera, the inside of the outer mask is equally divided vertically and horizontally to create small squares, and the mask 2 (1) The total number of lines from the first horizontal line where the declaration signal is generated to the last horizontal line is added up and compared with the standard character vertical dimension as the vertical dimension of the character.

A fifth invention similarly relates to another inspection method for measuring the horizontal dimension of printed characters, in which the characters printed inside the outer mask are imaged by a camera, and the inside of the outer mask is equally divided vertically and horizontally to create small squares. The total number of lines from the first vertical line where a binarized signal occurs to the last vertical line in this mask is integrated to obtain the horizontal dimension of the character, which is then compared with the standard horizontal dimension of the character. .

The sixth invention is a method of inspecting the pattern of printed characters and the presence or absence of handstand, which includes taking an image of the printed characters with a camera,
The captured character signal is binarized, the 2-1 digital signal is divided by a clock, and one character is divided into two.
It will be determined by comparing it with each value of each character divided into two parts.
This is what I did.

Similarly, the seventh invention is a method of inspecting the pattern of printed characters and the presence or absence of handstands, in which the inside of the mask outside the image is divided into small squares, and character signals generated by binarization are divided into two squares.
Divide, and set the total number of lti signals as 0) within each division to P4
It is designed to be compared with the numerical values of each of the two semi-characters.

The eighth invention is an inspection method for determining patterns and blurring of printed characters, in which characters on printed matter are imaged with a camera,
The imaged character No. 18 is divided horizontally into multiple parts for each character, and the threshold is set for each dividing line, and the peak differential exceeding l\r is calculated by
digitize, divide the binarized signal with a clock, and create a rectangular wave.
The wave number is compared with the standard character pattern count to make a determination.

The ninth invention is an inspection method for similarly determining patterns and blurring of printed characters, in which the outer square of the image is divided into multiple squares to create small squares, and the peak differential number in the square and the pattern count of standard characters are counted. The decision is made by comparing the

A tenth invention relates to a device for comparing and inspecting the number of printed characters, and a waveforming circuit that binarizes an image signal of printed characters captured by a camera and divides the binarized signal with a clock to produce a rectangular wave signal. As described above, the number of characters is compared and determined from the position of the character block.

The eleventh invention relates to a device for comparatively inspecting the vertical width of the printed characters, which binarizes the image signal of the printed characters imaged by a camera, and divides the binarized signal with a clock to form a rectangular wave signal. Equipped with a molding circuit, it has a horizontal OR circuit that performs OR processing of character signals for each VD line of imaging, and a character signal generated by OR processing in the vertical direction! , lI, the integrated value is taken as the character height width, and a comparison circuit is provided for comparing it with a standard value of character height width.

The twelfth invention relates to a device for comparatively inspecting the horizontal width of the printed characters, which captures an image with a camera, binarizes the imaged signal of the printed characters, divides the binarized signal with a clock, and generates a rectangular wave No. 18. It is equipped with a vertical OR circuit that performs OR processing of the character signals of each VD line of the image pickup, and a horizontal integration circuit that integrates the character signals generated by the horizontal OR processing in the horizontal direction. It is equipped with a comparison circuit for comparing the width of the characters with the standard value of the character width.

The thirteenth invention relates to an apparatus for inspecting the presence or absence of handstand in the printed characters, which binarizes an image signal of the printed characters captured by a camera, and divides the binarized signal by a clock to generate a waveform of a rectangular wave signal. A vertical OR circuit that sequentially performs an OR process on the character signals of each line of imaging, a half-folding circuit that divides the number of continuous signals (li) of character signals into two, and a It is equipped with a half-fold dot integrated circuit that integrates the first half and second half character signals, and a half-fold dot comparison circuit that compares the integrated value with the reference half-fold count number, and outputs dots of 1/2 vertical character. It is something.

13 And the 14th invention relates to a device for detecting patterns and blurring of printed characters, and includes a differentiation circuit that differentiates an image signal of printed characters imaged by a camera for each line, and a differential value set to a required threshold. A waveform type circuit that cuts the peak value according to the level, divides the peak value exceeding the peak value using the clock t, and converts it into a rectangular wave, and a line integration circuit that sequentially stores the total number of peak values for each VD line. Equipped with a comparison circuit to compare with standard pattern count,
By selecting the threshold level above, the character pattern,
It is designed to judge blur.

[For production]

The number of printed characters and the vertical and horizontal dimensions of the characters are determined by imaging a 21-digit signal, using a rectangular wave, and measuring the number of characters. Also, when characters are turned upside down (reversed), the number of character signals is halved,
This is done by comparing each with standard values. Furthermore, for blurred characters, etc., among the differential values, only the peak value exceeding the threshold level is measured.

=14= Furthermore, since these judgments of acceptability are made based on the integration of rectangular waves (or peak differentials (IG)), they are not affected by positional deviations from standard characters.

〔Example〕

1 to 7 show embodiments of the present invention.

11) Measurement object \\l and the characters printed on it (as shown in Figure 8(a) above.)
4JQ is an outer mask.

Prior to measuring the letters Pa and Pb of the above-mentioned III constant W, the printed letters Aa and Ab of the standard product are measured and memorized, and the standard character measurement memorization circuit is transferred to No. 4 II.

First, a standard product was photographed using a CCD camera I, and then colored.
'su';p) [1! By circuit 2, the ground color level (general (
The allowable width is determined in 71 steps for the 1'1 color measurement and the print color measurement. The outline is shown in Figure 5.

(r3 and S are scanning lines, the vertical axis indicates color density,
A is the topping density, B is the ground color density, and ±a.

± 1) (Each is a tolerance difference] <In the case, QO in the figure indicates the color concentration of each character, and AO shows the color concentration of each character.

Note that the tolerance ±a, ±1] is the threshold level for the color level. The color above is the color Renopel memory 1 (
J” path 3.

Next, the vertical and horizontal dimensions of the outer mask Q are measured by the outer mask detection circuit 4. Figure 6 shows characters Pa and Pb printed inside the outer mask Q.
As an example, it is assumed that "5R" is printed, and an example will be shown in which this is scanned and stored. ] The number VN at the right end of the diagram indicates the scanning line number. That is, the vertical dimension of the outer mask Q is between the second scanning line and the first and third scanning lines.

When this vertical dimension is measured and stored, a signal within threshold 1 of the image pickup signal ±a is converted to 21ig, divided by a clock, and made into a rectangular wave Valv l+.

The number of scanning lines during this time is read and used as the vertical dimension.

Next, when measuring the lateral dimension, the signal within the threshold level ±a in the imaging signal is binarized and divided by a clock.
VI) Square wave ha on the line.

Get b b. Calculate the product of the number of clock signals between both waveforms and use it as the width dimension. Then, these length]] width dimensions are stored in the outer mask basic prefecture mouth path 5.

Only the inside of the mask Q other than F is processed. (The outer mask may be set manually.) Next, read the number of characters ('1).

Reading the horizontal dimension of the outside mask (here, starting from the signal t+a of the first V Il line-L and the signal that first appeared after that, convert the signals of each VD line in the outside mask into 21 straight lines, and "Separate it with a cock, make it into a square wave, and
', V+) line below as a sheath and sequentially performs OR processing.

When the signal resulting from this OR processing ζ is continuously generated, one character is assumed.

One point is closed at the point where the signal is cut off, and the next (No. 4 appears.
11 is determined by the constant circuit 6, and the appropriate position in the middle is set as the character segment both points 1+c.

This is done over the entire length within the width of the outer mask 0, and the character number reading circuit 7 determines (the number of division points 1) as the number of characters, and this is stored in the character number storage circuit 8.

7 Next, detect the width of the character. In this case, do this for each character.

O for the character signal in the reading work of the number of characters.
Continuously generated signal after R processing (see Figure 6 (11d))
Accumulate. In the closed system, the horizontal character width "6" is the total value. This calculation is performed in each character width search circuit 9, and the allowable width is added and applied and stored in the character width storage circuit 10.

Next, detect the height of the character. In this case as well, this is done for each character.

The imaged character signal is binarized and divided by a clock to form a rectangular wave, and the generated No. 18 is OR-processed for each VD line. This O
The R-processed rectangular wave is indicated by VC in FIG. This signal VC is integrated to form a vertical width. Vertical character width in closed system
8" has a total value of -C. This calculation is performed in each character wc width search circuit 11, and the allowable width is added and applied and stored in the character height storage circuit 12.

Next, do a cross count. This is because even if the width of the character matches the standard character, the type is upside down and the installation +j
Figure 7e) is shown in Figure 7(e). To detect this, one character is divided in half and calculated for each half character.

11) First, the character width is as shown above.
The half-fold calculation point I'Ie is calculated and set for each character.

Next, the generated signal (the above-mentioned rectangular wave No. 13) tlf of each VI) line is integrated for each half character, and then all the lines are added up, and the total is taken as the half-fold count. 6th
In the figure, the half-fold count number of the letter Pa is r14J,
rl;3J. Also, those of the character pb are rlsJ, rl
6". This is done in the half-fold pulse number accumulating circuit 13, and by adding an allowable width, the half-fold count number storage circuit 1
4 is applied and stored.

Next (detect the differential B-I-HA number for each character.

This is to determine the pattern and blur of printed characters.The character signal inside the imaged outer mask is differentiated, a common threshold level is set, and the prominent peak values are converted into a rectangular wave. do.

=19- (Fig. 6bz, I+11). And each VD
It is stored line by line and goes to 'ifi' in generation 1110. For the letter P, 2. 2. 2. 2.
2. 2. 4. 2, and the letter P )] is 2. 4. 4. 2゜4,, 4. 4. , 4
becomes.

This is used to recognize patterns and blur. These are differentiated by the character differentiation circuit 15, arranged in the peak number 1116 order storage circuit 16, and input to the pattern count 17.

Next, the print inspection procedure for the printed matter W to be sent will be explained based on FIG.

First, the CCD camera 20 captures an image, and the first comparison circuit 21
The color density is compared with the color storage circuit 3 and the print color density is detected. However, FIG. 7(a) shows the color density of the sign letters Aa and Ab, and the color density of the printed characters Pa and Pb is the color density A.
The swords within ha (Shikoku b) are judged to be of good quality. However, if the printing density exceeds this or if this is detected other than printing (
When the condition shown in Fig. 3 (1) occurs, it is determined to be good or dirty and is discharged. Next, the second comparison circuit 22 compares the ground color with the ground color of the 0-color level memory circuit 3, and the ground color density B±1]
When it is within, it is 1'11. However, if the printed color density does not reach < A + a as shown in Figure 2, it is judged as insufficient color density (Figure 7 ``), and in addition to printed characters, the point e (third close) where the density exceeds the upper limit of the ground color is When detecting the problem in Figure 7 (d)), it is determined that this is the case, and both are discharged.

Above 1. If the second comparison circuit determines that the product is good, the signal is then binarized in the waveforming circuit 23ζ, divided by the clock T, and converted into a quadrature wave by the output mask circuit 24. The vertical and horizontal dimensions are compared with the outer mask base circuit 5 to determine the funding. In this case, the method for reading the outer mask vertically and horizontally is the same as the method for reading the standard product, and the explanation thereof will be omitted. (The outer mask may be set manually.) If it is determined to be a good product, the next determination of the number of printed characters is made. First, the vertical OR circuit 25 performs OR processing on the rectangular wave signals of each VD line using the second and lower signals as sheaths, and the character section is determined by the determination circuit 26 in accordance with the Standard 1 - Standard product measurement procedure. Then, the number of sections is integrated by the integration circuit 27, and from this, the number of characters is calculated by the calculation circuit 28. and comparison circuit 29
A comparison is made with the character number storage circuit 8 in .

Next, in order to check the handstand of the characters, when the above OR signals are read continuously, the total number should be detected at 1/2 point by the half-folding circuit 30 (point he in Figure 6), every half character. Then, the number of signals generated on each VD line is integrated in the integration circuit 31 in the same way as the measurement procedure for the standard product, and compared with the half-fold count storage circuit 14 in the comparison circuit 32.

After the comparison of one character is completed, the comparison circuit 33 similarly compares the next character every half character based on the signal from the character segment signal N.

In this case, as shown in FIG. 7(e), when the second character Pb is upside down, the half-fold count 1 shown in FIG.
8-16 becomes 16-18, and a handstand can be determined.

Next, when measuring the width of printed characters, each character is divided into characters by the character division signal N that is emitted when determining the number of characters, and the OR signal that is continuously emitted for each character is integrated by an integrating circuit 35. Character height memory circuit 12 for numerical values
The comparator circuit 36 compares the . After the comparison of one character is completed, the next character width is compared by applying the character segment signal N.

FIG. 7(g) shows a state in which the width g of the second character pb is smaller than the standard width G due to a printing defect.

Next, in measuring the vertical width of a printed character, the rectangular wave formed by binarizing and dividing by a clock is ORed with the VD line in by a horizontal OR circuit 40, and the character division signal N is used to generate a rectangular wave for each character. The integration circuit 41 integrates all lines every ]7. Then, the comparison circuit 42 compares each character with the character height storage circuit 12. After the comparison of one character is completed, the height of the next character is compared by applying the character division signal N.

FIG. 7(f) shows a case where the height of the second character Pb is defective in printing and the height 2 is smaller than the height I5 of the marker v2.

Next, the procedure for measuring the differential value of each printed character will be explained.

”2 The generated signal imaged by the camera 20 is transferred to the differentiating circuit 4.
4, and the comparison circuit 45 compares the width with an appropriately selected threshold level 46. The peak values that protrude above and below are divided by the clock T in the waveforming circuit 47 to form a rectangular wave. Then, the number of signals for each VD line is stored in an integrating circuit 48 and compared with the pattern count 17 in a comparing circuit 49. This is repeated for each character, and the quality of the pattern is determined.

FIG. 7(l) shows an example in which a notch m is formed in the second character Pb. In this case, if the notch m is clear and has a certain length, it is determined that the number of characters is two.

However, there are cases where the notches m are so small that they can be judged as two characters. However, when differentiating along the VD line, even minute notches can be detected reliably. In other words, there is a method that can reliably detect even minute changes in the pattern.

〔Effect of the invention〕

According to the present invention, the image signal of the printed characters received by the camera is binarized, divided into square waves by l':1, and this is read in the horizontal direction to determine the number of characters and the horizontal width of the characters. Since the measurement is made, the measurement can be carried out accurately. In addition, since the character width is cut by 1, and each character is read by ζ, if the characters stand on end during printing, this can be easily detected.

Also, the vertical width of a character can be measured by reading the rectangular wave in the vertical direction.

Furthermore, since the image pickup signal is differentiated along the VD lines, the differential values are summed for each VD line, and the results are compared, changes in minute patterns, blurred characters, etc. can also be read.

Furthermore, in each of the above measurements, when comparing with the standard product, square waves or differential waves were integrated along the VD line or in a direction perpendicular to this, and the total value was compared with the total value of the standard product. Therefore, it is possible to simplify the measurement circuit without being affected by slight misalignment of the printing.

[Brief explanation of the drawings] Figure 1 is a block circuit diagram of the measurement method, Figures 2 and 3 are illustrations of scanning lines showing the color density of different printed characters, and Figure 4 is the measurement of standard products. A block circuit diagram of the method, Fig. 5 is an explanatory diagram of scanning lines showing the color density of standard printed characters, Fig. 6 is an explanatory diagram of the operation of each function in each of the above blocks, and Fig. 7 is a diagram showing the quality of printed characters. An explanatory diagram, FIG. 8, is an explanatory diagram of a conventional method for measuring printed characters. 20 is a camera, 23 is a waveform type circuit, 25 is a vertical OR circuit, 26 is a character segment determination circuit, 29 is a character number comparison circuit, 3
0 is a half-fold circuit, 31 is a half-fold dot integrated circuit, 32 is a half-fold dot comparison circuit, 40 is a horizontal OR circuit, 41 is a vertical integration circuit, 42 is a vertical width comparison circuit, 44 is a differentiation circuit, and 47 is a waveform type 4 is a line integration circuit, 49 is a comparison circuit, and T is a clock. 27- g Square Hei 5 54δδυ(9)

Claims (14)

[Claims] (1) Image the characters on printed matter with a camera, binarize the imaged character signal, divide the binary signal with a clock to create a rectangular wave, detect the space between characters, calculate the number of characters, and calculate the standard number of characters. A printed character inspection method characterized by detecting an excess or deficiency in the number of characters and blurred characters compared to the original number. (2) A camera takes an image of the characters printed inside the outer mask, divides the inside of the outer mask vertically and horizontally into small squares, generates an image by binarizing it, and generates a binary value between the images. Character spacing is determined when the number of consecutive squares without a conversion signal exceeds a set value, and the number of characters is calculated from this character spacing number and compared with the standard number of characters to detect excess or deficiency in the number of characters or blurred characters. How to inspect printed characters. (3) Image the characters on the printed matter with a camera, convert the imaged character signal into a binary signal, divide the binary signal with a clock to create a rectangular wave, and measure the vertical and horizontal dimensions of each character from the vertical and horizontal rectangular wave numbers used to display the character. A printed character inspection method characterized by calculating and comparing with standard values of character height and width. (4) A camera images the characters printed inside the outer mask, divides the inside of the outer mask equally vertically and horizontally to create small squares, and within this mask, the binarized signal is generated from the first horizontal line to the last. A method for inspecting printed characters, characterized in that the total number of lines up to the horizontal lines that have occurred is integrated to determine the vertical dimension of the character, and the result is compared with a standard value for the vertical width of the character. (5) A camera images the characters printed inside the outer mask, divides the inside of the outer mask equally vertically and horizontally to create small squares, and divides the inside of the mask from the first vertical line where the binary signal is generated to the last. A printed character inspection method characterized in that the total number of lines up to the generated vertical line is taken as the horizontal dimension of the character, and compared with a standard character width value. (6) Capturing characters on printed matter with a camera, binarizing the captured character signal, dividing the binarized signal with a clock to create a rectangular wave, dividing one character into two, and converting each division into total binarization. A method for inspecting printed characters characterized by comparing the numbers and the values of two standard character divisions to detect character patterns and the presence or absence of handstands. (7) A camera captures an image of the characters printed inside the outer mask, divides the inside of the outer mask equally vertically and horizontally to create small squares, generates an image in this by binarizing, and converts the generated characters into two. A method for inspecting printed characters, which comprises dividing the characters and comparing the total number of binary signals generated in each division mask with a standard character 2-division value to detect character patterns and the presence or absence of handstands. (8) Image the characters on the printed matter with a camera, horizontally divide the imaged character signal into multiple parts for each character, and extract the peak signal that exceeds the required threshold level from among the differential signals appearing for each dividing line into binary values. A method for inspecting printed characters, characterized in that the binary signal is converted into a rectangular wave using a clock, and the pattern of this wave number is compared with a standard character pattern count to determine the character pattern and blurring. (9) Take an image of the characters printed inside the outer mask with a camera, divide the inside of the outer mask equally vertically and horizontally to create small squares, differentiate the character signal generated in the squares, and calculate the required value among the differential values. A printed character inspection method characterized by comparing a pattern of the number of peak occurrences exceeding a threshold level with a pattern count of standard characters to determine character patterns and blurring. (10) The image signal of the printed characters captured by the camera is
It is equipped with a waveforming circuit that converts the binary signal into a rectangular wave signal by dividing it with a clock, and when the signal for a character is continuously generated, it is regarded as one character, and when the character signal is absent for a certain (clock) time, the character block position is determined. What is claimed is: 1. A printed character inspection device comprising: a character block determination circuit that determines the number of characters; and a character count comparison circuit that determines the number of characters from the position of the block and compares it with a standard number of characters. (11) The image signal of the printed characters captured by the camera is
Equipped with a waveforming circuit that converts the binary signal into a rectangular wave signal by dividing it with a clock, and a horizontal OR circuit that performs OR processing on the signals for characters for each VD line of imaging, as well as all lines for each character generated by the OR processing. What is claimed is: 1. A printed character inspection device comprising: a vertical integration circuit for integrating signals; and a vertical width comparison circuit that takes the total value of the integrated signals as the character vertical width and compares the vertical width with a standard value of the character vertical width. (12) The image signal of the printed characters captured by the camera is
It is equipped with a waveform type circuit that converts the binary signal into a rectangular wave signal by dividing it with a clock, and a vertical OR circuit that sequentially performs OR processing on the character signals of each VD line of the image, and a 1. A printed character inspection device comprising a horizontal integration circuit that integrates signals in the horizontal direction, and a circuit that uses the total value of the integrated signals as the character width and compares it with a standard value of the character width. (13) The image signal of the printed characters captured by the camera is
It is equipped with a waveform type circuit that converts the binary signal into a rectangular wave signal by dividing it with a clock, and a vertical OR circuit that sequentially ORs the character signals of each VD line of imaging, and a a half-folding circuit that separates the characters, a half-folding dot integrated circuit that respectively integrates the first and second half character signals separated by the half-folding circuit, and a half-folding dot comparison circuit that compares the integrated value with a reference half-folding count number, A printed character inspection device characterized by detecting the presence or absence of handstand of characters by comparing the number of dots of half vertical characters. (14) The image signal of the printed characters captured by the camera is V
A differentiation circuit that differentiates for each D line, a waveform type circuit that cuts the differential value by a required threshold level, divides the peak value exceeding this by a clock and converts it into a rectangular wave, and a peak value for each VD line. A printed character inspection device comprising a pattern storage circuit for sequentially storing the total number and a comparison circuit for comparing this with a standard pattern count, and determining character patterns and blurring by selecting the threshold level. .