JP3109669B2 - Printing surface monitoring sensor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a printing surface monitoring sensor.

2. Description of the Related Art A conventional printing surface monitoring sensor is disclosed in
No. 8 discloses this. In other words, this monitoring sensor sequentially arranges a plurality of sets of one light receiving element and two light emitting elements on both sides as one set, and emits light emitted from each light emitting element.
Touch the print surface to be measured. The reflected light is received by a light receiving element and converted into an electric quantity so that the printed surface can be monitored.

Problems to be Solved by the Invention However, this type of monitoring sensor has a long shape, and in order to monitor a long narrow band portion on the printing surface,
When the paper is shifted from the predetermined position, the information of the printing surface already stored and the information of the printing surface detected by the monitoring sensor are different. For this reason, the same page is determined to be a different page.

The misalignment is a case in which the entirety of the signature placed on the signature stacking board of the collating machine or the lowermost sheet is shifted in the front-rear direction or the left-right direction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing surface monitoring sensor that can correctly detect the same sheet of paper even if the sheet is displaced in the front-rear direction or the left-right direction without determining the same sheet as a different kind of sheet.

Means for Solving the Problems The present invention constitutes a light receiving element group forming a matrix by arranging a plurality of light receiving elements in a row direction and a column direction so as to be a plurality of rows and a plurality of columns, and arranged in this manner. A plurality of light emitting elements are arranged around the outside of the light receiving element group. Light emitted from the light emitting element is applied to a printing surface to be measured, and the reflected light is received by the light receiving element group to obtain information on the printing surface. The data is converted into electric quantity, and the data is interpolated with the interpolated data based on the interpolated data in both the row direction and the column direction, and the interpolated data and the interpolated data are interpolated. A printing surface monitoring sensor configured to cope with a deviation of the printing surface by developing in a matrix form is a solution.

EXAMPLE Referring to FIG.

A plurality of light receiving elements (for example, R ₀₀ , R ₀₁ ...) Are arranged in a row direction and a column direction so as to form a matrix. A plurality of light emitting elements (for example, 6, 6a) are arranged around the light receiving element group 3 arranged in this way. The light emitted from each light emitting element is applied to a printing surface 5 to be measured shown in FIG. 2, and the reflected light is received by a light receiving element, for example, _R08 , and converted into an electric quantity to monitor the printing surface. is there.

A printing surface monitoring sensor (hereinafter, referred to as a sensor) which is a main component of the present invention will be described with reference to FIGS.

[Sensor 1] In this embodiment, the sensor 1 is square in the plane of FIG. The substrate 2 has a light receiving element group 3 and a light emitting element group 4.

[Light Receiving Element Group 3] Light receiving elements (for example, R ₀₀ , R ₀₁ ...) Are arranged 11 each in the row direction (X) and the column direction (Y), forming a 121 matrix.

[Light Emitting Element Group 4] The light emitting element group 4 is arranged so as to surround the light receiving element group 3. The light of each light emitting element 6 irradiates the printing surface 5 with light. This irradiation light is reflected by the printing surface 5 and received by the light receiving element group 3. This reflected light has the printing information of the printing surface 5. The light receiving element group 3 stores the pattern of the reflected light from the printing surface 5.

Each light receiving element converts a light receiving signal into an analog electric signal level. Each light receiving element does not output an on / off signal corresponding to black and white.

Here, a light emitting diode can be used as the light emitting element, and a photodiode is used as the light receiving element.

According to FIG. 2, the light receiving element group 3 and the light emitting element group 4 are protected by the transparent protection plate 7. This is to prevent dust and debris from entering the printed matter. Electronic components 9 for the light receiving element group 3 and the light emitting element group 4 are arranged on the back surface of the substrate 2.

If the example of the dimensions of the above-mentioned sensor is shown, the length x width is 42 mm x 42 mm in the plane of Fig. 1. Also, the width D is 11 mm as viewed in the cross section of FIG.

[Sensor 3 and Signature Stack 10] Reference is made to FIGS. 3 and 4. FIG.

The sensor 1 shown in FIG. 1 is provided below the signature platform 10 of the collator as shown in FIGS. A signature 11 is placed on the signature platform 10. The sensor 1 detects the lowermost printing surface 5 of the signature 11. At that time, signature 11
Is monitored by the sensor 1 and then pulled out by a vice or other means in the direction of arrow A to a conveyor (not shown).

[Collator and Monitoring System] FIG. 5 shows a collator and a monitoring system. A plurality of signature stackers 10 of the collating machine are arranged. This signature stacking platform 10
Is shown small. A sensor 1, a piece unit 20, and an operation panel 21 are arranged for each signature platform 10. Each sensor 1 and each operation panel 21 is a corresponding piece unit
Connected to 20. One sensor 1 or another sensor 1 may be provided as shown by a broken line in FIG. All piece units 20 are connected to the master unit 22.
The master unit 22 is connected with an alarm lamp 23, a buzzer 24 and a machine stop switch 25.

The piece unit 20 is connected to the starter 27 via the starter repeater 26.
It is connected to the. Based on the start signal of the starter 27, each sensor 1 of each frame unit 20 is sequentially operated.

The failure indicator light 21a of the operation panel 21 is illuminated when necessary when the sensor 1 detects a different kind of paper, and notifies the operator as a failure signal.

[Frame unit 20] An example of the function of the frame unit 20 will be described below.

(1) Piece unit based on command from operation panel 21
20 performs the following operations.

If there is a first starter input, the stored data is discarded, and data is newly taken in from the sensor 1 to be used as standard data. The inspection starts from the next starter input.

A command to turn off the fault indicator light 21a is sent to the operation panel 21.

 Turn off the defective output to the master unit 22.

 A release signal is output to the master unit 22.

 Prepare for black calibration.

 Prepare for white calibration.

The various data specified by the previous input is incremented by one. Send plus 1 data to the operation panel.

Various data designated by the previous input is decremented by one. Send the minus 1 data to the operation panel.

 Import the increased / decreased data set value.

 Perform the prepared calibration.

When there are two sensors 1, the selection of the sensor is switched. If either is not connected, select the connected one.

 The number of the selected sensor is sent to the operation panel 21.

 The test result is sent to the operation panel 21.

(2) Similarly, in response to a command from the master unit 22, the piece unit 20 performs the following operation.

The data stored so far is discarded and data is newly taken in from the sensor and used as a reference.

 A command to turn off the fault indicator light 21a is sent to the operation panel 21.

 Turn off the defective output to the master unit 22.

 A release signal is output to the master unit 22.

 Prepare and calibrate for black calibration.

 Prepare and proofread white.

(3) When the starter 27 is input, the piece unit 20
Takes data from the sensor 1 and performs inspection.

When the power is turned on, preparation is made so that the inspection can be performed with the various set values backed up. When there is an input of the first starter, data is fetched from the sensor 1 and used as reference analog signal data.

When the next starter is input, the reference analog signal data is compared with the detected analog signal data on the printed surface to perform an inspection.

As a result of the inspection, when it is determined that the product is non-defective, the defective number counter is reset, and when the defective holding flip-flop is OFF, a defective indicator OFF command is sent to the operation panel to turn off the defective output to the master unit. Fault indicator and fault output are OFF when fault holding flip-flop is ON
Do not.

As a result of the inspection, when it is determined that the types are different, the number of defective sheets counter is incremented by one. When the defective number counter is equal to or larger than the content of the defective number memory, a defective indicator ON command is sent to the operation panel 21 to turn on the defective output to the master unit.

The test is performed when the test flip-flop is ON,
When it is OFF, no inspection is performed.

(4) Response example from the piece unit 20 to the operation panel 21 When the power is turned on, the state of the inspection flip-flop, the selected state of the sensor, the state of the failure holding flip-flop, and the like are sent to the operation panel 21.

It responds to commands from the operation panel or master unit.

(5) Example of input of previous frame data, input of rear frame data If a test command is sent from the operation panel 21 and sensor data has already been captured, it is compared with the sensor data of the previous frame and rear frame, and its own Test whether it is possible to judge with the allowance obtained by calculating the data.

When a test command is sent from operation panel 21,
First, a data request command is sent to the I / O with the previous frame in order to take in the data of the previous frame. Next, the data of the sensor of the previous frame is taken.

Next, a data request command is sent to the I / O with the rear frame in order to take in the data of the rear frame. Next, the data of the sensor of the rear frame is fetched.

If the previous frame or the rear frame is not connected, there is no response to the data request command.

In addition, there are data output to the front frame and data output to the rear frame.

(6) Output the judgment result, starter, etc. to the master unit 22.

The failure output to the master unit of the judgment result of the inspection is
O if the defective holding flip-flop is ON or OFF
FF, turn on if defective. The output timing is immediately after the determination result is obtained.

The starter outputs the signal of the starter input as it is. Output regardless of the state of the check flip-flop.

(7) Initial setting of memory and each I / O at power-on.

 Clear memory, flags and counters.

 Initialize I / O.

 Send initial data to the operation panel.

The fault output and alarm output to the master unit are turned off when the power is turned on.

[Calibration of each light receiving element of sensor 1] An example of calibration will be described.

Calibration includes black calibration and white calibration. The calibration is performed to normalize the analog signal from each light receiving element of the sensor 1. This analog signal is taken in through an 8-bit A / D converter. Since it is an 8-bit digital signal, the data has 0 to 256 levels. The normalization is performed so that the black level becomes 0 and the white level becomes 200 among the 256 levels.

Calibration must first be performed from black. An error will occur if you attempt to perform white calibration.

The black calibration is performed by setting correction amount data in an 8-bit D / A converter for black correction. When 0 is set, there is no correction, and as the value becomes larger, the correction amount increases, and becomes maximum at 255. White calibration is performed by setting data in an 8-bit D / A converter for gain adjustment. Apply the analog signal after black correction to D /
The gain is adjusted by the A converter and amplified. When 0 is set, the gain is 0, and as the value becomes larger, the gain increases.
It becomes the maximum at 255. The configuration is performed by a black calibration or white calibration command from the operation panel 21 or the master unit 22.

Calibration is performed simultaneously for the two sensors on each signature platform.

Black calibration black reference paper is placed on the detection surface of the sensor 1. First, the maximum gain of 255 is set in the white D / A converter. Black D /
When 0 is set in the A converter and the A / D conversion value is 2 or less, the sensor is regarded as not connected.

Next, the black D / A converter is set sequentially from 1 to 255, and the black D / A value at which the A / D converter becomes 2 or less is stored as a black calibration value. If the A / D conversion value does not become 2 or less even when 255 is set in the black D / A converter, black calibration failure is determined. At this time, the black calibration value is stored as 255.

White calibration White reference paper is placed on the detection surface of the sensor 1. First, the black calibration value is set in the black D / A converter. The white D / A values are set in the white D / A converter in order from 0 to 255, and the A / D conversion value at which the A / D conversion value becomes 200 or more is stored as a white calibration value. If the A / D conversion value does not become 200 or more even when 255 is set in the white D / A converter, it is determined that the white calibration is defective. At this time, the white calibration value is 255
To be stored.

[Set of Number of Defective Sheets] The number of defective sheets is set to output a signal indicating an inspection failure to the master unit 22 or the operation panel 21 at the time of inspection, and to determine how many consecutive defective wafers are output. That is, when five sheets are set, if five or more sheets are continuously determined to be defective, a signal indicating an inspection failure is output to the master unit or the operation panel. Further, an alarm output is output each time it is determined to be defective regardless of the number of sheets set.

[Determination Method] As described above, the sensor 1 has 11 light receiving elements in the row direction and 11 points in the column direction. That is, the light receiving element is an area sensor. The light receiving elements are multiplexed by 4 bits in the vertical direction (column direction) and 4 bits in the horizontal direction (row direction), and selected and input one by one. The input signal of each light receiving element of the sensor (S ₀₀ , S
₀₁ ...) is taken in as an 8-bit digital signal through an 8-bit A / D converter.

(1) Capture of standard and interpolation Standard data for inspection (S ₀₀ , S ₀₀₎ at the first starter input or at the starter input after the memory command unless various command operations are performed after the power is turned on.
₀₁ …)

As shown in Table 1, the captured data is sequentially represented by S ₀₀ , S ₀₁ , S _01
02 ,…, S _0A , S ₁₀ , S ₁₁ ,…, S ₁₉ , S _1A , S ₂₀ , S ₂₁ ,…, S _A0 , S _A1 ,
…, S _A9 , S _AA .

When these data are interpolated by the average of the front, rear, left, and right data, the total of 441 points (21 points in length and 21 points in width) including the original data is obtained.
It becomes point data. This data is sorted in order as shown in Table-2.
₀₀ , A ₀₁ , A ₀₂ ,…, A ₀₉ , A _0A , A _0B ,…, A _0J , A _0K , A ₁₀ , A ₁₁ ,…, A
_{1J, A 1K, A 20,} ..., A K0, A K1, ..., A KJ, When A _KK, a calculation such as Table 3 in detail.

This data is stored as standard data. If two sensors 1 are connected, similarly, data is taken in from another sensor to obtain interpolation data. This data is also 21 points vertically and 21 points horizontally, for a total of 441 points.

(2) Determining the reference value Out of a total of 441 data points (21 points vertically and 21 points horizontally) of the standard data, 3 points vertically out of a total of 49 points (7 points vertically and 7 horizontally) near the center
A total of 25 points are selected in order. Table 25 shows these 25 cases.

The difference between the maximum value and the minimum value among the selected nine points is obtained, and the largest one of the 25 differences is stored as a reference value. If two sensors are connected, a reference value is obtained for each.

(3) Determination of Inspection Rank Inspection ranks A to F are determined as shown in Table 5 based on the difference between the maximum value and the minimum value of the nine data points stored as reference values. Inspection is performed based on the allowance and error rate that can be determined by this rank. When the rank is determined, the result is sent to the operation panel 21 in FIG. When two sensors are connected, both ranks are determined, and the rank sent to the operation panel is the rank of the selected sensor.

(4) Incorporation of comparative value After the standard value is acquired and the rank is determined, raw data for comparative inspection is acquired by the next starter input. At this time, unlike the standard value, the data to be taken is limited to the selected sensor.

This data consists of 11 points vertically and 11 points horizontally, 121 points in order, C ₀₀ , C ₀₁ , C
₀₂ ,…, C _0A , C ₁₀ , C ₁₁ ,…, C ₁₉ , C _1A , C ₂₀ , C ₂₁ ,…, C _A0 , C _A1 ,
…, C _A9 and C _AA .

When these data are interpolated with the average value of the front, rear, left, and right data in the same manner as the standard value, the data becomes 21 points vertically and 21 points horizontally, for a total of 441 points. This data is sequentially written as D ₀₀ , D ₀₁ , D ₀₂ ,…, D ₀₉ , D
_0A , D _0B ,…, D _0J , D _0K , D ₁₀ , D ₁₁ ,…, D _1J , D _1K , D ₂₀ ,…, D _K0 , D
_K1, ..., D _KJ, when the D _KK, a calculation such as Table 6.
This data is used as a comparison value.

(5) Judgment of comparison value The standard value and the comparison value are compared to check whether they match, and to judge whether they are good or different.

First, a search is made as to where the data of the nine reference values selected from the standard values have moved in the comparison values. A total of nine points of three points in the vertical direction and three points in the horizontal direction are sequentially selected from the comparison value, and a difference from the nine points of the reference value is obtained. When this difference does not exceed the allowance determined by each set rank, it is assumed that the reference value has moved to the position of this comparison value.

Next, the standard value and the comparison value are compared in the same positional relationship as the movement of the reference value. Also at this time, the values exceeding the allowance determined by the rank are summed for each of the positive and negative values, and the sum of the absolute values of each of the positive and negative values is calculated. This sum is divided by the number of points compared and 1
Find the error per point. When the error rate exceeds the error rate determined by the rank, it is determined that the sheet is of a different type, and when the error rate does not exceed the error rate, it is determined that the sheet is good.

If it is determined to be non-defective, the comparison is terminated, and this comparison value is finally determined to be non-defective.

If it is determined to be different, a point at which the reference value has moved is searched for in the comparison value, and if it can be found, the whole is compared with the same positional relationship. In this way, the point at which the reference value has moved is searched for over the entire comparison value, and if all are different, it is finally determined to be different. If it is finally determined that the type is different, an alarm is output, and a defect output is performed according to the setting of the number of defective sheets. If it is determined to be non-defective, the fault output and the like are turned off in accordance with the fault holding setting.

If the reference value movement position cannot be found from the comparison values when the number of defective sheets is set to 2 or more, it is finally determined that the reference position is different, but at this time, nine reference values and the comparison value are determined. Then, the one having the smallest sum of the absolute values of the positive and negative differences is selected, and the whole is compared with the same positional relationship. When the difference between the compared points exceeds twice the allowance, an alarm output and a failure output are output regardless of the setting of the number of defective sheets.

Effect of the Invention As described above, according to the printing surface monitoring sensor of the present invention, a printed matter can be monitored on a relatively large surface, and it is possible to cope with a case where the printing surface is shifted from a predetermined position. Therefore, the quality of the printed surface can be reliably monitored, and the collating operation can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a printing surface monitoring sensor according to the present invention, FIG. 2 is a sectional view showing a part of the sensor, and FIGS. 3 and 4 are provided on a signature platform. Diagram showing a sensor,
FIG. 5 is a diagram showing a collator and a monitoring system. 1 ...... printed surface monitoring sensors 3 ...... light receiving element group 4 ...... emitting element group 5 ...... printing paper 6, 6a ...... emitting element R ₀₀ ...... light receiving element 10 ...... signatures Sekidai

Claims (1)

(57) [Claims] A plurality of light receiving elements are arranged in a row direction and a column direction in a plurality of rows and a plurality of columns to form a matrix of light receiving element groups, and a light receiving element group outside the light receiving element group arranged in this manner is formed. A plurality of light emitting elements are arranged around, and the light emitted from the light emitting elements is applied to the printing surface to be measured, the reflected light is received by the light receiving element group, and the information on the printing surface is converted into an electric quantity. Data is fetched, and interpolation is performed between the fetched data in both the row direction and the column direction with interpolation data based on the fetched data, and the fetched data and the interpolated data are developed in a matrix. A printing surface monitoring sensor configured to cope with a printing surface deviation.