JP2872441B2 - Printing evaluation method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for evaluating the printing of a device which outputs a dot pattern such as an ink jet recording head.

[0002]

2. Description of the Related Art Conventionally, when evaluating the quality of a recording head or a printer body in an ink jet printer or the like,
It has been common practice to draw an evaluation pattern on a predetermined sheet of paper and sensually evaluate it visually by an inspector.

[0003]

However, in the sensory evaluation by visual inspection of the inspector, there are individual differences among the inspectors who perform the evaluation, and there are variations in the evaluation due to the fact that the evaluation cannot be performed quantitatively.

[0004] The present invention has been made in view of the above points,
It is an object of the present invention to provide a printing evaluation method and apparatus capable of eliminating variations in evaluation, and in particular, performing accurate evaluation for dirt.

[0005]

According to the present invention, a predetermined evaluation pattern is drawn on a recording material by an output device to be evaluated, the drawn pattern is picked up by an image pickup device, and gray-scale image data obtained thereby is obtained. Is generated, a first edge image (contour line image) is generated from the grayscale image, and an enlargement / reduction (expansion / contraction) process is performed on the first edge image to generate a second edge image. An edge extraction process is performed on the second edge image to generate a third edge image, and in the third edge image, a shape feature value for each region separated by a contour line is extracted, and based on the shape feature value. Thus, there is provided a print evaluation method characterized in that the quality of the output device to be evaluated is determined.

Further, according to the present invention, an evaluation pattern in which straight lines are arranged at predetermined intervals is drawn on a recording material by an output device to be evaluated, and the drawn pattern is imaged by an imaging device. Storing the one-dimensional average density data in the line direction of the evaluation pattern from the grayscale image data, and calculating the evaluation in the vicinity of the sheet density of the recording material from the distribution state of the average density in a direction perpendicular to the line direction. The present invention provides a printing evaluation method characterized by measuring the line width of a straight line of a use pattern, and judging the quality of the output device to be evaluated according to the line width.

Further, according to the present invention, there is provided an image pickup means for reading an evaluation pattern drawn by an output device to be evaluated, a storage means for storing grayscale image data corresponding to the evaluation pattern outputted from the image pickup means, First edge extracting means for generating a first edge image from grayscale image data, processing means for performing an enlargement / reduction process on the first edge image to generate a second edge image, and A second edge extraction unit that performs an edge extraction process on the edge image to generate a third edge image, and a calculation that calculates a shape feature value for each region of the third edge image separated by a contour line Means for judging the quality of the output device to be evaluated based on the shape characteristic value.

According to the present invention, there is provided an image pickup means for reading an evaluation pattern in which straight lines are arranged at predetermined intervals, drawn on a recording material by an output device to be evaluated, and the evaluation pattern outputted from the image pickup means. Storage means for storing grayscale image data according to the above, obtains one-dimensional average density data in the line direction of the evaluation pattern from the grayscale image data, and calculates the average density distribution state in a direction perpendicular to the line direction. Processing means for obtaining data relating to the line width of a straight line of the evaluation pattern in the vicinity of the paper surface density of the recording material, and determining whether the output device under evaluation is good or bad according to the data relating to the line width. Provided is a printing evaluation device characterized by the following.

According to the present invention, an edge image is generated from grayscale image data obtained by automatically reading an evaluation pattern drawn by an output device under evaluation, and enlargement / reduction processing is performed on the edge image. After that, the edge is extracted again, the shape characteristic value of each area separated by the contour line of the edge image is obtained, the pattern and the dirt are identified from the shape characteristic value, and the state of the dirt is detected.

For a stain that cannot be detected by the shape characteristic value, a line width is obtained from a one-dimensional average density in the line direction of the pattern, and the line width detects the stain.

Thus, the contamination is quantitatively evaluated.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(1) Recording Head FIGS. 1 to 5 are diagrams showing the configuration of an ink jet recording head to be inspected in the present embodiment. The ink jet recording head discharges ink from a discharge port by using thermal energy. is there.

In the drawing, reference numeral 3001 denotes a plurality of discharge ports for discharging ink arranged in a straight line, and 3002 denotes a heater arranged for each discharge port. The heater generates heat when energized, and heats the ink to cause film boiling. And ink is ejected from the ejection port in the P direction. Reference numeral 3003 denotes a silicon plate on which a discharge port 3001 and a heater 3002 are formed. Reference numeral 3004 denotes a ceiling member having a groove 3005 and a discharge hole formed for each discharge port. An ink flow path is formed. Reference numeral 3006 denotes an ink tank for supplying ink to the ink flow path. Reference numeral 3007 denotes an aluminum plate, which has a reference surface 3008a-f for fixing the silicon plate 3003 and improving the position accuracy with respect to the position of the heater 3002.

Of the reference surfaces on this aluminum plate 3007,
Reference numerals 3008d and 3008f denote reference surfaces in the arrangement direction of the ejection ports 3001 (hereinafter referred to as X direction), 3008c denotes a reference surface in the ink ejection direction (P direction) (hereinafter referred to as Y direction), and 3008a, 3008b and 3008e denote This is a reference plane for a direction perpendicular to a plane to be formed in the X and Y directions (hereinafter, referred to as a Z direction).

Reference numeral 3009 denotes a printed board fixed to an aluminum board 3008 and a silicon board 3003 connected by wire bonding 3011. Also printed board 3009
Has a pad 3010 on a surface where a connector for a signal from the main body of the recording device or a printing evaluation device to be described later contacts, and the pad 3010 and the wire bonding 3011
And a conductor pattern 3012 for connection with a pad for use.

Next, the inspection apparatus for the recording head will be described.

(2) Inspection Apparatus Main Body FIG. 6 is a plan view showing the entire configuration of the inspection apparatus according to the present embodiment, and includes a work setting mechanism 500 for fixing a recording head (hereinafter also referred to as a work), and a fixed work. A moving mechanism 700 provided with paper on which a predetermined test pattern is printed by a work, and a measuring mechanism 800 for reading the test pattern from the paper in the moving mechanism 600. Next, each mechanism will be described.

(A) Work setting mechanism 500 FIG. 7 is a rear view of the work setting mechanism viewed from the direction of arrow A in FIG. This will be described below with reference to FIGS. Reference numeral 501 denotes a work clamp unit for clamping a work to be inspected, which is set manually by an operator, and will be described later in detail. 502-1, 502-
Reference numeral 2 denotes a work fixing unit for fixing the set work W, which is provided on a rotary table 505 that is rotated about a shaft 504 by a rotary table rotation drive source 503. Work fixing parts 502-1 and 502-2
Have work fixing arms 521-1 and 521-2 and work fixing jigs 523-1 and 523-2, respectively. The work fixing arms 521-1 and 521-2 each have a work holding member for fixing the work W. 506-1, 506-2 and driver substrates 508-1, 508 for the work W and the head
2 are provided with work connection contact pins 507-1 and 507-2 for electrically connecting them to each other. Reference numeral 509 denotes a contact pin fixing arm provided with a contact pin 510 for a rotary table, which is vertically moved (in the direction of FIG. 7C) along two shafts 512 by a contact pin vertical drive cylinder 511. At the time of test printing, the contact pin fixing arm 509 is lowered to the position indicated by the broken line in FIG. As a result, the rotary table contact pins 510 are connected to the two rotary table contact pin receiving pads 513-1 or 513 provided on the rotary table 505.
-2, the driver board 508-1
Alternatively, a signal for printing a test pattern is transmitted to 508-2. Reference numeral 514 denotes a tube for supplying air to the cylinder 511 for vertically driving the contact pin, and a contact pin fixing arm 509 in accordance with the air supply.
Moves up and down. Reference numeral 515 denotes an air supply solenoid for supplying air to the tube 514.

FIG. 8 shows details of a work clamping unit 501 for fixing the work W. In the drawing, reference numeral 551 denotes a work fixed arm drive cylinder for driving the work fixed arm 521, which is fixed to a cylinder fixing tool 552, and which is supplied with air to thereby allow the work fixed arm 5 to be driven.
Reference numeral 21 moves in the direction (I direction) along the work fixed arm drive shaft 530 to release the clamp of the work W.
When the air supply is stopped, the work fixing arm 521 is moved by the spring 527 to the work fixing arm drive shaft 5.
The workpiece W is moved along the direction 30 in the clamping direction (J direction), and the workpiece W is clamped by the workpiece pressing member 506-1 and the workpiece connecting contact pin 507-1.

553 is a work fixed arm drive cylinder 5
An air receiving port fixing jig having an air receiving port 554 for 51. Reference numeral 555 denotes an air supply port that can be joined to the air receiving port 554, and can be moved in the K and L directions by an air supply port driving cylinder 556. 557 is an air supply solenoid for supplying air to the air supply port driving cylinder 556, and 558 is for supplying air to the fixed arm driving cylinder 551 when the air supply port 555 and the air receiving port 554 are in a joined state. Air supply solenoid.

When the rotary table 505 is stopped, the air supply port 555 described later is moved in the direction (K direction) toward the rotary table by the air supply port driving cylinder 556 when the rotary table 505 is stopped.
5 and the air port 554. Then, air is supplied from an air supply port 555 to an air receiving port 554 on the rotary table 505, and the pressure of the air drives the work fixing arm driving cylinder 551, and the work fixing arm 521 fixed thereto is moved along the drive shaft 530. To release the clamp. When the rotary table 505 rotates, the air supply solenoid 55
7 is driven to stop the air supply. Thus, the work fixing arm 521 is moved in the J direction by the spring 527 to clamp the work. Thereafter, the air supply port 555 is moved by the air supply port driving cylinder 556 in a direction (L direction) in which the air supply port 555 can be separated from the rotary table 505, and after being separated, is rotated.

FIGS. 13A to 13C are views showing the work clamping unit 501 in detail. In the figures, the same members as those in FIGS. 6 and 8 are the same members. 521 is provided with a work holding member 506-1, a work connecting contact pin 507-1, and a drive direction converter 522, and a work fixing arm 523 movable in the direction of arrow D is provided with a work fixing jig 523 fixed to the rotary table 503. 507, a work holding member 506-1 or 506-2 provided on the work fixing arm 522 and a work connecting contact pin 507 for the work fixing jig 523.
The workpiece W is fixed when the workpiece W is pressed by -1 or 507-2. The driving direction converter 522 is shown in FIG.
As shown in (b), the driving force transmission lever has a surface oblique to the moving direction of the work fixing arm 522 and is moved up and down in the direction of arrow E by a work fixing release cylinder 524 provided on the base. A roller 526 (FIG. 8C) provided at the tip of 525 is movable in the direction of arrow D. 527 is a spring for pressing the work fixing arm 522, and 528 and 529 are sensors for detecting the position of the driving force transmission lever.

The clamp and release of the work W are performed as follows. When the air is not supplied to the normal work fixing release cylinder 524, the cylinder is separated from the driving force transmission lever 525 and the spring 527 acts to push the work fixing arm 522 toward the work, thereby disposing the work fixing arm 522 on the work fixing arm 522. The work holding member 506 and the work connection contact pin 507 press the work W, and the work W is fixed between the work fixing jig 523 and the work holding member 506.

When air is supplied to the work fixing release cylinder 524, the driving force transmission lever 525 on the rotary table 505 is pushed, and the roller 526 on the upper surface of the lever moves on the work fixing arm drive shaft.
A force along the drive shaft 530 is generated by the drive direction converter 522 having a surface that abuts on the roller 526 having a surface inclined with respect to the drive direction. , The work holding member 506 and the work connecting contact pin 507 are separated from the work W, and the work W can be replaced. Sensors 528 and 529 are arranged to detect the upper and lower ends of the movement of the driving force transmission lever 525 by the work fixing release cylinder 524, whereby the work clamp release position and the work clamp position can be detected. I have.

As described above, the work W has the six reference surfaces 3008a to 3008f. The work fixing jig 523 is provided with the reference surfaces so that the work W can be fixed.
When setting, abut against this reference plane and fix it.

(B) Recovery mechanism 600 FIG. 9 shows the details of the recovery mechanism, and FIG. 10 shows the principle of the recovery operation. In the inspection apparatus according to the present embodiment, after the work W is clamped and before the test printing, the suction recovery operation is performed on the work W to prevent clogging due to dust or the like. 60
Reference numeral 1 denotes a recovery port that comes into contact with the discharge surface of the work W, 602 denotes a recovery vacuum pump for sucking ink in the work W from the discharge port, 603 denotes a recovery mechanism fixing jig, and 604 denotes a drive shaft for the recovery port 601. A recovery port moving cylinder for moving forward or backward in the direction of arrow F along 606, an air supply solenoid 605 for supplying air to the recovery port moving cylinder 604, and a recovery vacuum pump 602 for suction 607. This is an ink discharge port for discharging the discharged ink. Reference numerals 608 and 609 denote sensors for detecting the position of the recovery port.

The recovery port 601 of the recovery mechanism 600 is made of a soft material such as rubber and has a larger opening than the surface where the ejection ports of the head are arranged and a wall surface smaller than the surface where the ejection ports of the head are arranged. A trumpet-shaped member having a hole for suction in a part thereof, and a tube connected to the recovery vacuum pump 602 is connected to the hole. The recovery port 601 is connected to the recovery port moving cylinder 6.
10 comes in contact with the workpiece by moving forward
As shown in (b), the tube is closed except for the hole of the tube connected to the recovery vacuum pump 602. When the air in the space A surrounded by the recovery port 601 and the work W is vacuumed by the recovery vacuum pump 602, a negative pressure is applied to the hole of the head, and the ink is sucked from the discharge port. As a result, the discharge port where the ink is hard to come out due to dust or the like can be immediately printed.

(C) Paper transport mechanism 700 FIG. 11A is a rear view when the paper transport mechanism is viewed from the direction of arrow G, and FIG. 11B is a side view when the paper transport mechanism is viewed from the direction of arrow H. FIG.

Reference numeral 701 denotes a paper supply reel on which a roll paper 751 on which a test pattern is printed is wound, 702 denotes a paper take-up reel for winding the paper, and 703 denotes a reel of the take-up reel 702 as shown in FIG. A drive shaft is connected to the shaft 752, and a motor for rotating the roll paper wound on the paper supply reel 701 in a winding direction is provided. Reference numeral 704 denotes a plurality of rollers for feeding the paper. Paper supply reel 701 and reel shaft 7
As shown in FIGS. 12 (a) and 12 (b), a felt 752 is used to apply tension to the paper supply reel 701.
Is provided.

Next, reference numeral 705 denotes a paper suction jig provided with a plurality of vacuum holes on a surface for sliding the paper, the details of which are shown in FIG. The plurality of holes 753 are connected to the tube 706 via the ventilation path 754, and are sucked by the air vacuum solenoid 709 to adsorb the paper when the test pattern is printed.

The above members are arranged on a paper supply unit table 708, and the paper supply unit table 708 moves a vertical drive stage 711 vertically with respect to a stage fixing table 710 by driving a paper supply unit drive motor 709. By doing so, it is possible to move in the Y direction.

The above members can be moved in the I direction (X direction) together with the moving stage 712 by driving the moving motor 713.

A weak voltage is applied to the motor 703 in the direction in which the paper take-up reel 702 is wound. Even in this state, the brake is applied so that the paper supply reel 701 does not rotate. That is, since the felt 752 having soft elasticity is wound around the shaft 751 of the paper supply reel 701, a weak brake is applied by the frictional resistance generated between the inner surface of the paper supply reel and the felt and the paper supply reel shaft. In this state, tension is applied to the paper, and the paper is vacuumed from the hole 753 of the paper suction jig 705 to fix the paper. Before performing the next inspection, a high voltage is applied to the motor 702 to overcome the brake for a certain period of time, and the motor 702 is rotated in the paper winding direction to wind the paper. After a certain time, the motor 702
Again apply a weak voltage to stop the paper and vacuum. The path of the paper is limited by moving along a plurality of roller axes.

The paper supply unit table 708 includes a vertical drive stage 711 movable in the Y direction provided on a stage fixing table 710 fixed to the moving section of the paper moving stage 712.
And the paper suction jig 705 can be moved up and down. This is necessary at the time of high magnification measurement of a printed test pattern as described later.

(D) Measuring mechanism 800 In FIG. 6, reference numeral 801 denotes a two-dimensional image pickup device having a high-magnification optical system, and 802 denotes a two-dimensional image pickup device having a low-magnification optical system. 803, 804
And illumination sources 805 and 806 are provided. A read signal from the two-dimensional imaging device is output to an image processing device described later.

In the present embodiment, in order to inspect a plurality of items as described later, a test pattern is read using two two-dimensional imaging devices 801 and 802 each having an optical system having a different magnification.

For example, in order to measure the landing position of a droplet coming out of each nozzle, the position of a dot printed by each nozzle must be measured with a resolution of about 5 μm. At this time, the measurement area becomes 2.5 mm mouth (500 x 500 pixels), and the measurement system or printed paper is moved four times to measure the landing position of the droplet by the head having a nozzle length of 10 mm. And image processing.

In the case of measuring different patterns of density unevenness in the nozzle array direction using the same optical system, the resolution is 25 μm.
m, the measurement area is 12.5 mm (pixel 5
00 × 500), and 1 for this test.
A head having a nozzle length of 0 mm can be measured at one time. Therefore, in order to shorten the measurement time, it is better to arrange a plurality of two-dimensional imaging devices having an optical system with a magnification required for measurement.

In this embodiment, the image pickup device 801 has a high-magnification optical system, and is used for inspection of a displacement (distortion) of a landing position of a droplet. The imaging device 802 has a low-magnification optical system,
Used for density unevenness inspection in the nozzle array direction.

(3) Control Unit FIG. 14 is a block diagram showing a control unit of the inspection apparatus in this embodiment. In the figure, 100 is a main CPU, and RO
M, a RAM, and the like, and controls each unit of the inspection apparatus main body according to a program described later. Reference numeral 101 denotes a rotary table controller 113 for controlling rotation of the rotary table 505 and a contact pin vertical drive cylinder 51.
This is an interface for sending a control signal from the main CPU 100 to an air supply solenoid 515 for supplying air to the air supply 1. 102 is a main CP for the air supply solenoids 557 and 558 in the work clamping unit.
This is an interface for transmitting a control signal from U100. 103 is an air supply solenoid 6 in the recovery mechanism 600.
05 and the recovery vacuum pump 602
This is an interface for transmitting a control signal from the PU 100. This is an interface for sending a control signal from the main CPU 100 to a paper winding motor 703 and an air vacuum solenoid 707 for adsorbing paper in the paper transport mechanism 700. Reference numeral 105 denotes a stage driver that sends a drive signal from the main CPU 100 to the paper supply unit drive motor 709 and the paper movement motor 712 in the paper transport mechanism 700.

Reference numerals 111 and 112 denote imaging devices 801 and 8
This is an image processing device that performs a predetermined process for inspection on the image signal output from the image signal 02, and its details will be described later.
The outputs from the image processing devices 111 and 112 are 106, 10
7 to the main CPU 100.

Reference numeral 109 denotes an operation unit having various keys such as a start key 120, and a key input signal is input to the main CPU 100 via the interface 108. Another one
Reference numeral 10 denotes a CRT for displaying inspection results and the like.

Output signals from various sensors provided in the work set mechanism 500, the recovery mechanism 600, and the paper transport mechanism 700 are also input to the main CPU 100, and the main CPU 100 receives the output signals from the sensors based on the sensor output signals. Perform operation control.

(4) Description of Operation Next, the operation of the inspection apparatus will be described with reference to FIG.

FIG. 15A is a flowchart showing a basic operation flow of the inspection apparatus in this embodiment. First, the rotary table 505 is rotated (step 10).
0). Then, it waits for the worker to exchange the work W with respect to the work fixing unit (502-1 in FIG. 6) (step 2).
00), when the work exchange is completed, the recovery mechanism 600 performs a recovery process on the work W (step 300).
Then, after the recovery processing, the rotary table 505 is rotated again, and the work W is set at the print position facing the roll paper (step 400). Then, a predetermined test pattern is printed, the roll paper on which the test pattern is printed by the paper transport mechanism 700 is moved to a measurement position, and measured by the imaging devices 801 and 802.
Predetermined processing for inspection is performed in steps 11 and 112 (step 500). Then, the measurement result is displayed on the CRT 110 (step 600).

The above is the basic operation flow. In this embodiment, since the rotary table has two work fixing portions, the process of measuring and displaying the result on the work fixed to one of the work fixing portions is performed. It is possible to perform work conversion and recovery processing on the other work fixed part while performing. In this embodiment, the operation flow is shown in FIG.
The result is as shown in FIG.

FIGS. 15 (c) to 15 (f) show FIGS.
It is a flowchart which shows operation | movement in each step of (b).

Each operation will be described below with reference to FIGS. Here, the operation when the work clamping unit shown in FIG. 8 is used will be described.

(A) Work exchange processing Two work fixing parts 502- of the rotary table 505
The main CPU 100 controls the air supply solenoid 557 via the interface 102 to release the work clamping state of the work fixing portion (502-1 in FIG. Is turned on, and the air supply port driving cylinder 556 turns the air supply port 5
55 is advanced (K direction) so as to be coupled with the air receiving port 554 (step 201). When the sensor 559 detects that the air supply port 555 has moved forward and has been coupled to the air receiving port 554 (step 202), the air supply solenoid 5
Then, air is supplied to the fixed arm driving cylinder 551 to move the work fixing arm 521 in the unclamping direction (I direction) until the sensor 561 is turned on, and the work holding member 506 and the work connecting contact pin 5 are moved.
07 is separated from the work W after the inspection is completed (step 20).
3, 204). Then, the exchange of the work is displayed on the CRT 110 (step 205).

After the operator sees this and takes out the work after the inspection, inserts the untested work into the gap between the work fixing arm 521 and the work fixing jig 523, and then the start switch 120 on the operation unit 109 is turned on. (Steps 206 and 207).

When the main CPU 100 has the start switch 1
When the on of 20 is detected, the air supply solenoid 558 is turned off. Thereby, the work fixing arm 521 is moved in the clamp direction (J direction) by the spring 561,
The work is held by the work holding member 506 and the work fixing jig 523.
And fix it. At the same time, the work connection contact pin 507 is connected to the work pad 3010 (FIG. 5). When the sensor 562 detects the clamp state of the workpiece (step 209), the air supply solenoid 557
Is turned off, the air supply port 555 is moved backward (L direction) until the sensor 560 is turned on, separated from the air receiving port 554, and the next operation is started (steps 210 and 211).

Here, the work connecting contact pin 50 is used.
7 is connected through a driver board 508 to a rotary table contact pin receiving pad 513 via a cable. The receiving pad 513 is connected to a contact pin fixing arm 5 by a contact pin vertical driving cylinder 511.
09 is lowered, and the contact pin fixing arm 509 is lowered.
The contact pin 510 for the rotary table attached to the end surface of the rotary table comes into contact with the receiving pad 513.

Accordingly, the main CPU 100 can print an arbitrary pattern using a work by sending a control signal to the driver board 508 via the interface 113.

Further, as the contact pin vertical drive cylinder 511 is raised, the rotary table contact pin 510 attached to the end face of the contact pin fixing arm 509 is separated from the receiving pad 513, and the rotary table 505 is rotated. Making it possible.

(B) Recovery Processing The work W is shifted to recovery processing after clamping. Main CPU1
00 turns on the air supply solenoid 605 via the interface 103 and advances the recovery port 601 by the recovery port moving cylinder 604 so that the recovery port 601 comes into contact with the discharge surface of the work W (step 301). When the sensor 608 detects that the recovery port 601 has moved to a position where it contacts the ejection surface of the work W, the main CPU 100
3, the recovery vacuum 602 is driven, and the air in the space A (FIG. 10) surrounded by the recovery port 601 and the work W is vacuumed by the recovery vacuum pump 602 for a certain period of time (steps 303 and 304). Thus, the recovery operation is performed by rinsing the ink in the work W from the ejection port. The ink rinsed from the work is the recovery port 6
01, a tube, and a recovery vacuum pump 602, and are discharged from an ink discharge port 607.

Then, the air supply solenoid 605 is turned off, and the recovery port 601 moves backward until the sensor 609 is turned on.

(C) Rotation processing of the rotary table When the main CPU 100 turns on the air supply solenoid 515 via the interface 101, the contact pin vertical drive cylinder 511 is driven and the sensor 5 is turned on.
The contact pin fixing arm 509 is raised until 16 is turned on (steps 101 and 102). As a result, the rotary table contact pin 510 provided on the end face of the contact pin fixing arm 509 is separated from the rotary table contact pin receiving pad 513.

After that, the main CPU 100 sends the rotary table controller 113 via the interface 101.
And outputs a control signal for rotating the rotary table. This allows the rotary table controller 1
13 turns on the rotary table driving source 503 and rotates the rotary table 505.

When the main CPU 100 receives a rotation completion signal from the rotary table controller 113 via the interface 101, a measurement end signal for the previous work is output from the image processing devices 111 and 112 via the interfaces 106 and 107. Under these conditions, the air supply solenoid 515 is turned off, and the contact pin fixing arm 509 is lowered until the sensor 517 is turned on by the contact pin vertical drive cylinder 511 (steps 104 and 105). As a result, the rotary table contact pins 510 and the rotary table contact pin receiving pads 513 are connected.

(D) Measurement Processing After the rotation processing of the rotary table, the main CPU 100 drives the paper movement stage drive motor 713 via the stage driver 105 for a fixed time to move the paper movement stage 712 in the M direction (FIG. 6). The printing position of the work W is set at a predetermined distance (50 mm in this embodiment) M from the paper suction jig 705.
Set to a position away from the direction (FIG. 6) (step 50)
1, 502).

The data stored in the RAM in the main CPU 100 is output to the stage driver 113 via the interface 113 to drive the paper moving stage drive motor 713, and the paper moving stage 712 is driven at 300 m / s.
Imaging device 801 with high magnification optical system at ec speed
Move until it comes to the position. When the main CPU 100 detects a signal from the sensor 770 which is turned on when the paper suction jig 705 reaches the printing position, the main board 100 detects the signal.
8 to the ROM in the driver board 508
(Step 50)
3, 504). After printing is completed, the paper supply unit drive motor 709 is turned on via the stage driver 105, and the paper supply unit 708 is moved in the Y direction for a predetermined time (steps 505 and 506). When the movement is completed, the main C
The PU 100 sends a control signal for starting measurement to the image processing devices 111 and 112 via the interfaces 106 and 107. After receiving this signal, the image processing apparatuses 111 and 112 perform a plurality of inspections described below, and send an end signal and the result to the main CPU 100 via the interfaces 106 and 107. The main CPU 100 displays the result on the CRT 110 to notify the operator (steps 507 to 509).

When the main CPU 100 receives from the stage driver 113 a signal indicating that the paper moving stage 712 has stopped at the measurement position of the image pickup device 801, it rotates the rotary table 505.

In the above embodiment, the work W is exchanged manually by the operator, but it is also possible to perform the exchange automatically using an automatic hand. In this case, the main CPU 100 is connected to the auto hand via a cable via an interface, a conversion start signal is sent from the main CPU 100 to the control of the auto hand when the work is exchanged, and the work exchange is started. To send an exchange end signal to

In the above embodiment, the test pattern is printed by moving the paper moving stage at the time of printing. However, the test pattern may be printed by fixing the paper and moving the work. Good.

Similarly, a configuration may be adopted in which the imaging device is moved also when reading the test pattern.

In the present embodiment, an ink jet recording head of a type in which ink is ejected using thermal energy has been described as an example of a recording head to be inspected. However, the present invention is not limited to this. And the like, in which ink is ejected using pressure energy of an electromechanical converter or the like. Further, a recording head of a thermal recording type using a thermal paper or an ink sheet may be used.

(5) Inspection Details Next, the details of the processing performed in the image processing apparatuses 1 and 2 (111 and 112) will be described in detail.

(A) Configuration of Image Processing Devices 1 and 2 FIG. 16 is a block diagram of the image processing devices 1 (111) and 2 (112).

Referring to FIG. 16, reference numeral 181 denotes a ROM in which a boot program of the apparatus is stored;
184 is an FDD (floppy disk drive) which is an external storage device for recording an execution program and parameters;
183 is an FDC (Floppy Disk Controller) for controlling the 184 FDD 184, 185 is a main CPU
A serial I / O such as RS-232C for communicating with the input / output devices such as the CRT 110 and the operation unit 109, and the like, 188 is provided between the image processing apparatus 1 (111) and the image processing apparatus 2 (112). GP that communicates large amounts of data on the Internet
IB or the like parallel I / O, 189 is the aforementioned imaging device 80
1 (hereinafter, referred to as camera 1) and an image signal from the imaging device 802 (hereinafter, referred to as camera 2) are converted into digital image signals and input, and the digital image signals are converted into a monitor TV 190.
193, an image memory for storing a digital image signal, 194, a binarization processing unit for converting a grayscale image signal into a binary image signal, and 195, numbering of connected areas and identification of areas. Label processing unit for enabling
Reference numeral 6 denotes a feature amount calculation unit that calculates a feature for each region in the image.
Controlled by 0. Further, an image input / output unit 189, an image memory 193, a binarization processing unit 194, a label processing unit 19
5. The transfer of image data between the feature amount calculation units 196 is performed at high speed via the image bus 198.

(B) Relationship between pattern imaging regions FIG. 17 is an example showing the relationship between a test pattern, which is a test pattern printed on roll paper by the work W, and the imaging regions of the TV cameras 1 and 2.

Reference numeral 210 denotes a pattern 1b of the patterns 1a and 211, a pattern 2b of the patterns 2a and 213,
The pattern 3a of 214 and the pattern 3b of 215 are the same patterns, respectively, and the relative movement directions of the head (work W) and the roll paper at the time of pattern formation are different. That is, 2
The pattern 1 a of No. 10, the pattern 2 a of 212, the pattern 3 a of 214 are forward printing, and the pattern 1 of 211 is
The pattern 2b of b, 213 and the pattern 3b of 215 are return path printing.

In such a pattern, the pattern 1 is a paper moving stage 7 for measurement by the TV cameras 1 and 2.
Of the twelve reciprocating motions, measurement is performed twice for each of the forward and backward trips, for pattern 2 once for each forward trip and return trip, and for pattern 3 once for each round trip and return trip. The pattern 1 and the pattern 2 use a TV camera 1 having an optical system for high magnification in order to perform high-luminance measurement.
The imaging is performed twice in the Z direction, and the pattern 3 is imaged once using the TV camera 2 having a low-magnification optical system in order to grasp the entire pattern. Therefore, the imaging area is 14 areas in total.

FIG. 18 is a diagram showing the contents of the measurement condition data 250 stored in the RAM in the main CPU 100.

The main CPU 100 stores the measurement condition data 2
With reference to 50, a command is sent to the paper moving stage 712, the image processing device 1 (111), and the image processing device 2 (112) to perform a measurement process.

The measurement condition data 250 includes an imaging region number 251 for identifying the imaging region, and a measured pattern
A stage 71 for moving the paper so as to be in the field of view of the cameras 1 and 2
2 moving positions 252 (1) and 252 (2), image processing device numbers 253, 221 for specifying image processing devices for inputting and processing image signals of the pattern to be measured.
Area connection data 254 (1) and 254 (2) for identifying that the 22 imaging areas 2 are connected, and pattern number 2 for identifying a pattern and performing a process in accordance therewith
55 and the print direction 256 are stored for each imaging area in the order of the measurement processing. After the final imaging area, (imaging area number) = − 1 is stored as data indicating the end of the measurement condition data.

(C) Measurement Process FIG. 19 is a diagram showing a flow of the measurement process. Hereinafter, a case where the measurement is performed according to the contents of the measurement condition data 250 will be described as an example.

First, the main CPU 100 sets the data 250 (1) relating to the first imaging area of the measurement condition data 250.
, The position data X = 10 of the paper moving stage 712
00, Y = 100, and issues a movement command to the paper movement stage drive motor 713 based on this data, and waits for the movement to be completed (S201). Next, measurement condition data 2
With reference to the image processing device number of 50 (1), the process proceeds to the process (S203 or S205) corresponding to the image processing device number (S202). At this time, if data indicating an image processing apparatus that does not exist is stored (in this embodiment, a value other than 1 or 2 is stored), it means that measurement is not performed at this position, Area confirmation step (S2
07).

In this embodiment, since the image processing apparatus number is 2, an image input command is transmitted to the image processing apparatus 2 of 108 to input a pattern image (S205).
I do. At this time, along with the image input command, measurement condition data 2
50 (1) and final area information indicating whether or not it is the final measurement area for each image processing apparatus. Whether or not the current area is the last area of each image processing apparatus can be confirmed by referring to the image processing apparatus number 253 of the measurement condition data 250 for the current area and thereafter.

On the other hand, upon receiving the image input command, the measurement condition data 250, and the final area information (S220), the image processing device 2 (112) inputs an image signal based on the measurement condition data 250 (S221).

Here, “based on measurement conditions” means, for example,
In order to select an optical system that matches the target pattern (in this embodiment, the pattern number is 1, the high-magnification optical system is selected), the camera input of the image processing apparatus 2 (112) is switched. . At this time, the combination of the pattern number and the optical system is set in the image processing apparatuses 1 and 2 in advance.

When the input of the image signal is completed, the image processing device 2 (112) transmits an image signal input completion signal to the main CPU 100 (S222). Main CPU
Upon receiving the image signal input completion signal from the image processing device 2 (112) (S206), the process 100 proceeds to a remaining measurement area confirmation step (S207).

In the remaining measurement area confirmation step (S207), it is confirmed whether or not the data is end data by referring to the imaging area number of the next measurement condition data 250 (2). Since it means that an unmeasured area remains, a stage movement step (S201)
Then, the next measurement condition data 250 (2) is referred to.
Stage movement is performed (S201), and measurement condition data 2
Referring to the image processing device number 253 of 50 (2), since the image processing device number is 1 this time, the image processing device 1
For (111), an image signal input command, measurement condition data,
The final area information is transmitted, and the reception of the image signal input completion signal from the image processing apparatus 1 (111) is confirmed (S204).
The remaining measurement area confirmation step (S207) is performed. Upon receiving the image signal input command from the main CPU 100 (S210), the image processing device 1 (111) receives the image signal input command from the main CPU 100 (S210).
As in the image input step (S221) of (112), an image signal is input (S211), and the main CPU 100
, An image signal input completion signal is transmitted (S21).
2). When transmitting the image signal input completion signal to the main CPU 100, the image processing apparatuses 1 and 2 perform image processing corresponding to each pattern as described below (S213, S223),
Whether or not the current area is the last area is checked based on the last area information (S214, S224). If the current area is not the last area (imaging area number: 1 in the 250 measurement condition data)
-12) is an image signal input receiving step (S21).
0, S220), and in the case of the final area (in the case of the imaging area numbers: 13 and 14 in the 250 measurement condition data), the measurement data totaling process (S215 to S217,
S225 to S226) are performed.

The operation of the aggregation processing is performed by the image processing apparatus 1 (11
1) and the image processing device 2 (112) are different. In the image processing device 2 (112), the image processing step (S22)
The image processing results calculated in 3) are totaled for each measurement item (S225), and the image processing apparatus 1 (111) transmits the data with the possibility that the totaled data can be received. Preparations for the next measurement, such as initialization of the memory, are performed, and the process returns to the image signal input receiving step (S220) (S226). On the other hand, the image processing apparatus 1 (111) first receives the aggregate data from the image processing apparatus 2 (112) (S215), and then receives the aggregated data.
Of the data calculated inside the image processing apparatus 2
The final measurement result is calculated by integrating with the total data from (112) (S216).

As soon as the measurement result is calculated, the main CP
The measurement result is transmitted to U100, and preparation for the next measurement such as initialization of the memory is performed, and an image signal input step (S21) is performed.
0) (S217).

When the main CPU 100 determines that there is no remaining area in the remaining area confirming step, the main CPU 100 is in a state of waiting for reception of the measurement result. Therefore, when the measurement result is calculated by the image processing apparatus 1 (111), the measurement is immediately performed. The result is received (S2
08), the measurement processing is ended, and the processing is shifted to the comparison processing with the next standard value.

(D) Image Processing Next, the image processing apparatus 1 (111) and the image processing apparatus 2 (11)
The image processing performed in 2) will be described in detail.

FIGS. 20 and 21 are diagrams for explaining defective items that can be detected by the first image processing.

In the first image processing, the uniformity (position / shape) of dots is measured. The pattern in FIG.
This is an ideal pattern, and FIG. 21 is a pattern including non-uniform dots. In FIG. 21, part (a) shows a case where the positions of the dots are shifted left and right, and the straight line pattern is not a straight line. Part (b) shows the case where the dots are shifted up and down, and the connected straight lines are cut. Part (c) shows the case where the dot position fluctuates up and down, and the straight line is disturbed.
Part (d) shows a case where the dot size is not uniform, and the line width varies. Part (e) shows the case where the dot size is small. The straight line is a straight line, but the line width is narrow.

When the dots are non-uniform, the print pattern is disturbed.

FIG. 22 and FIG. 23 are diagrams for explaining print patterns used for the first image processing.

FIG. 22 is a view showing the tip of the recording head (work W). At the tip of the recording head, a plurality of holes (nozzles) 201 for projecting ink are arranged in the Y direction.
The print pattern is formed on the roll paper by moving the paper moving stage 712 and the recording head relatively in the X direction.

FIG. 23 is a diagram showing a print pattern as a test object printed on roll paper by the recording head.
Here, the dots di, j are output by the nozzle 201 (i), and in FIG. 23, if the Y direction (nozzle arrangement direction) is a column and the X direction (head movement direction) is a row, The dots dp, j belonging to the same nozzle 201
The dots belonging to (p) and belonging to the q-th column are dots formed by a plurality of nozzles at substantially the same time during the relative movement of the recording head.

The intervals between the dots are set so that adjacent dots do not touch each other. In this embodiment, simultaneous printing is performed every two nozzles in each row, and the intervals between the rows are set to be substantially the same. I have.

By using such a pattern, each dot is separated, so that the position and shape of each dot can be measured.

FIG. 24 is a diagram showing a flow of the first image processing. The flow after the image processing step of FIG.
17, S223 to S226).

In FIGS. 19 and 24, S21 in FIG.
3 and S223 are S301 in FIG. 24, S214 and S224 in FIG. 19 are S302 in FIG. 24, and S215 in FIG.
24, S216 and S225 in FIG. 19 correspond to S304 in FIG. 24, and S217 and S226 in FIG. 19 correspond to S3 in FIG.
05 respectively.

Step S301 in FIG. 24 is a step of measuring the position and shape data of each dot serving as basic data of the present processing. The step of measuring according to the coordinate system in each area (S311) and the positional relationship of each area Is taken into account, and a step (S313) of calculating position data in which the position of the paper moving stage 712 at the time of imaging is corrected is calculated.

In S304 of FIG. 24, the position
In this step, the measured value calculated in the shape measuring step (S301) is finally converted into an evaluation value for discriminating a non-defective / defective product.
A step (S316) of identifying whether or not it belongs to a "column";
23. A step (S317) of calculating each dot point position by least-squares approximation and calculating a position shift for each dot from a difference between the grid point position and each dot position (S317). (S 318).

FIG. 25 is a diagram schematically showing the operation of the dot position / shape measuring step (S311) of FIG.

FIG. 25A is a digital image of the measured pattern stored in the image memory 193, and each numerical value indicates the density value of each pixel.

FIG. 25B is a binary image separated into a dot portion and a background portion by threshold value processing of the density value. Here, the threshold processing refers to the original image

[0103]

[Outside 1] Output image by the following equation

[0104]

[Outside 2] Is the process of creating

[0105]

[Outside 3] Here, T is a constant and is called a threshold.

If the threshold value T is a fixed constant, the separation between dots and the background becomes unstable due to fluctuations in the amount of illumination light and the like. FIG. 25D is created. When the minimum density value is Min, the maximum density value is Max, and the number of pixels of a certain density i is G (i), the following equation is obtained.

[0107]

[Outside 4] T is obtained by the following equation using Min ′ and Max ′ that satisfy the following.

T = Min '+ t (Max'-Min') (t: predetermined number of 0 <t <1)

Here, t is a fixed value, but since Min 'and Max' follow up due to fluctuations in the amount of illumination, etc., a binary image stable with respect to fluctuations is output.

FIG. 25C is a label image in which each dot of the binary image of FIG. 25B is assigned a different number so that each dot can be identified. To make a label image, 2
Scanned values image B _p (x, y) at the order of the TV raster scan, the target pixel B _p (x, y)> 0, then 25
(E), four peripheral pixels (P _{i-1, j-1} , P _{i, j-1} ,
With reference to the label value of P _{i + 1, j-1} , P _{i-1, j} ), if there is a pixel that already has a label value, that value is used as the label value of P _ij , and the pixel with the label value If not, a new label value that has not been used is set as the label value of P _ij .
In the case of the portion (f) in FIG. 25B, two different label values exist in the reference pixel. In this case, the fact that the two labels are the same label is stored, and the correction is made after one scan is completed. The label image L _p (x, y) is obtained by such processing.

Next, from the label image L _p (x, y), the moment feature M _pq for each label represented by the following equation:
Find (k).

[0112]

[Outside 5]

In this moment feature, M ₀₀ (k) is the area of the label K, and M ₁₀ (k) / M ₀₀ (k) is x of the position of the center of gravity.
The coordinates, M ₀₁ (k) / M ₀₀ (k), represent the y-coordinate of the position of the center of gravity. Therefore, the position and shape of each dot can be measured by obtaining the moment feature amount.

FIG. 26 is a diagram for explaining the correction of the dot position data. Reference numeral 240 denotes a top image pickup area above the area where the target pattern is imaged twice (image pickup areas 1, 3, 5, and FIG. 17). (Corresponding to 7, 9, 11).
Reference numeral 241 denotes a lower side (the imaging areas 2, 4, 6, 8, 1 in FIG. 17).
(Corresponding to 0, 12). Stage 7 for moving paper
The relative movement command value from the imaging position of the first imaging area 240 to the imaging position of the subsequent imaging area 241 is

[0115]

[Outside 6] And the measured value of the dot d _ij in the top imaging area 240 is

[0116]

[Outside 7] The measured value in the subsequent imaging area 241 is

[0117]

[Outside 8] Then, assuming that the paper moving stage 712 moves as instructed,

[0118]

[Outside 9] However, due to the linearity of the drive system and backlash, etc.

[0119]

[Outside 10] Is generated. Therefore, the first imaging area 240 and the subsequent imaging area 241 are set so as to partially overlap each other, and two measurement values of dots in the overlapping area are set.

[0120]

[Outside 11]

In order to identify which dot in the first imaging region 240 and which dot in the succeeding imaging region 241 are the same, the interval between the dots is about 200 μm. Dot d _ij ,
Predetermined value L between the measured dots d _st subsequent imaging region 241 as (~ 100 [mu] m)

[0122]

[Outside 12] Is satisfied, _dij and _dst are regarded as the same dot.

As described above, after the measured value of the latent image capturing area 240 and the measured value of the subsequent capturing area 241 are converted into values of the same coordinate system, the measurement is performed in both the leading capturing area 240 and the subsequent capturing area 241 in the overlapping area. After deleting the measured value of one of the measured values of the dots, the stored value is stored in the memory 193.

In the present embodiment, the measured values of the succeeding imaging region 241 are adjusted to the coordinate system of the leading imaging region 240, but the correction may be reversed. Further, in the present embodiment, since the leading imaging region 240 is measured first, the subsequent imaging region 241 is imaged, the position of each dot is measured, and this correction is performed at the same time. However, the imaging order is reversed. In this case, it may be performed immediately before the step of identifying “row” and “column” (S316) in the step (S304) of the tallying process in FIG.

It goes without saying that the division of the area is not limited to two.

Next, a description will be given of the lattice points that are the basis of the evaluation value calculation step (S304 in FIG. 24) for discriminating a non-defective / defective product.

In FIG. 27, “○” indicates an actual dot,
“●” is a grid point obtained by calculation. As in FIG. 23, the arrangement in the i direction is called “row”, and the arrangement in the j direction is called “column”.

Here, in the case of an ideal printing pattern, the interval between each “row” and “column” is constant, and each “column” and “row”
By using vectors

[0129]

[Outside 13] The ideal position of each dot is determined.

More specifically, if each "row" and "column" of actual print dots are known,

[0131]

[Outside 14] The least squares normal equation is

[0132]

[Outside 15] And transform this,

[0133]

[Outside 16] Therefore, when evaluating the head alone,

[0134]

[Outside 17] Can be solved simultaneously. When the expression is changed by changing the expression form of the expression (11),

[0135]

[Outside 18] The number of dots in the ith column is N (i), and the sum of j is J
Assuming (i), equations (12) and (13) are

[0136]

[Outside 19] Substituting this into equations (14) and (15) gives

[0137]

[Outside 20] Is obtained from this

[0138]

[Outside 21] Is obtained, a grid point with an undetermined “row” interval is obtained.

Next, the step (S3) of the tallying process of FIG.
The actual operation of 04) will be specifically described.

FIGS. 28 and 29 are diagrams showing the storage format of the dot data obtained in the dot position / shape measurement step (S301). As the dot data, the X coordinate (X _ij ), the Y coordinate (Y _ij ), and the dot diameter (R _ij ) of each dot are stored as a set, and the number of dots in the area is stored.
After that, the data of the next area is stored in the same format. However, a dot whose area is not within a predetermined range is not stored and is determined as "dirt" or "dust" instead of a dot. The dot diameter R _ij is determined by the dot position / normal measurement step (S30).
From the dot area (S _ij ) obtained in 1), R _ij = 2√
It is an equivalent diameter calculated by S _ij / π.

In the dot data, since the data of each area is continuously stored, the image pickup area number (P _i ) of each area,
The number of dots (N _i ) and the head value (A _i ) of the data storage address are stored as a set in the dot data management table shown in FIG. 28, and the number of areas is stored at the head of the dot data management table. . If data is stored in such a format, the memory can be used efficiently even if the total number of dots changes.

The input command receiving step (S
At 210 and S220), the measurement condition data received from the main CPU 100 is stored, and the connection relationship of each imaging region is obtained from the measurement condition data and the dot data management table, and the “line” of each dot is obtained for each connection region. The “column” is identified, the grid points are calculated, and the evaluation value is calculated.

In this embodiment, the dot diameter R _ij is obtained from the area. However, in the dot shape measuring step, the perimeter L _ij is obtained from (circumference) = π × (diameter), and R _ij = L _ij.
/ Π.

FIG. 30 is a diagram for explaining the flow of processing for identifying the "row" to which each dot belongs.

In FIG. 30, first, the target dot =
1. Initialize the number of columns N _c = 0 (S330), and initialize the next column number i = 1 to be compared (S331). Comparing the number N _c of number i and column of the column (S332) to, if i <N _c, comparing the X-coordinate value X _k of the representative X-coordinate value G _x (i) a target dot row i (S333). At this time, G _x (i)
And if the difference between the X _k is larger than the predetermined value [delta] _x, since the dots k is separated from the column i, is determined not to belong to this column,
In order to compare with the next column, i is increased by 1 (S334) and the process returns to the check of the number of columns (S332).

On the other hand, when the difference between G _x (i) and X _k is smaller than a predetermined value δ _X , it is determined that the dot k belongs to this column,
The X coordinate (X _K ), Y coordinate (Y _K ), dot diameter (R _K ) of the dot k are called, and the number i of this row is stored (S33).
6). Then, to update the representative X-coordinate of the columns in the X _K, the number of dots belonging to the column is increased 1 (S337), then, by the dot number k is increased 1 (S338), if there are still the target dot ( S339), comparison with the column (S33)
Return to 1).

If the number of columns is checked in step S332 and i> N _C , it indicates that there is no column to which the dot k belongs. Therefore, the number of columns is increased by one to N _C = N _C +1 and i = N _C At the same time, the dot number G _N (i) of the new row is initialized to 0 (S335), and the dot data storage step (S33)
Perform 6).

When this series of processing is performed on all the dots, the numbers of the columns to which the dots belong are assigned, but the numbers are given numbers that are irrelevant to the order in which the dots are actually arranged. For example, FIG.
In the case of, the first, fourth, and seventh columns are marked with 1-3,
The fourth and fifth rows are labeled 4,5, and the third and sixth rows are labeled 6,7. This is because the processing is performed in the order of TV raster scanning at the time of dot position measurement, and the dot data is stored in that order. Therefore, it is necessary to rearrange the column numbers assigned in the processing of FIG. 30 so as to match the pattern.

FIG. 31 is a diagram for explaining the flow of processing for changing the column number from the left side in the imaging area.

In S340, the new column number k = 1 and the number N _c 'of effective columns used in the subsequent processing are initialized to the current total column number N _c . The number i = 1 of the column to be compared, the minimum value X _min of the representative X coordinate value of the column is set to a large value (for example, X _min = 999) (S341), and the representative value G _x (i) of X _min and the X coordinate of the column i is set. )
Are compared (S342). At this time, 0 <G _x (i) <
If X _min , then column i is to the left of X _min , so X
_min = G _x (i), the column number i is stored as I _min (S343), and the column number to be compared is incremented by 1 (S3).
44), the total number of columns _Nc is compared (S345), and if i < _Nc , there are columns to be compared, so the process returns to S342. i>
In the case of _Nc , since the comparison with all the columns has been completed, the column stored in I _min at this time is the k-th column from the left. Next, in order to determine whether or not the column I _min is a valid column, the number of dots G _x (I _min ) of the column I _min is set to a predetermined value N ₁ , N ₂ (N ₁
<N ₂ ) (S346), and N ₁ <G _n (I _min ) <N
If it is _2, it is determined to be a valid column, and the number ( _{Nc- Nc} ') obtained by subtracting the number of invalid columns from k in the conversion table is G ( _Imin ) = k-
(N _c -N _c ') and to register, subsequent processing by G _x (I _min) not to use this data = - G _x advance (I _min) and by reversing the sign (S347).

On the other hand, G _n (I _min ) <N ₁ or N ₂ <G _n
In the case of (I _min ), there is a strong possibility that the column is a column other than a dot such as a stain.
(I _min ) = 0 is registered in the conversion table, the sign of G _x (I _min ) is inverted as in the case of a valid column, the number of valid columns N _c ′ is reduced by 1, and N _c ′ = N _c '-1 (S3
50).

When the registration in the conversion table is completed, the new column number k is incremented by 1 to determine the next column (S348).
The new column number k is compared with the total number of columns _Nc (S349), and k
If < _Nc, there is a column for which a new column number has not been determined, so the flow returns to S341 to repeat a series of processing.

If k> _Nc , new column numbers have been determined for all columns, so using the conversion table G (i), D _G (i) = G (D _G (i)) (i = 1,2, ..., N
Update the column number according to _c ). Also, the total number of columns is updated with the number of columns _Nc 'excluding the invalid columns, and _Nc = _Nc '.

FIG. 32 is a view for explaining the flow of processing for determining a column and storing dot data for each column in accordance with the y-coordinate of the dot in order to identify which row each dot belongs to.

In the initialization step S360, the number of processed dots N _G (i) to N _G (N _c ) for each row is set to 0, and the target dot No. It is assumed that n = 1.

Next, the column number of the dot n is i (i = D
_G (n)), and the number of processed dots _NG (i) in column i is increased by one. At this time, the storage location j of the dot n is the _NG (i) -th data storage area of the column i (S361).

Here, before storing the dot data,
The y coordinate E _y (i, j−1) of the dot data stored at the j−1th position in the data storage area of column i and the y of the dot n
The coordinates D _y (n) are compared (S362), and E _y (i, j−
1) In the case of> D _y (n), since the dot n is a dot located above the dot stored in the j-1st area, the j-1th data is moved to the jth area. In order to shift the storage location of the dot n upward by 1, j = j−1 (S363), and the process returns to the y coordinate comparison step of S362.

The comparing step of the y-coordinate (S362) and the moving step of the stored data (S361) are performed by E _y (i, j-
1) When the process is repeated until <D _y (n) is satisfied, all dot data below the dot n are shifted by one area, and the area for storing the data of the dot n becomes empty. The data of dot n is stored in the area (S
364).

[0159] After that, the target dot number n is increased 1 (S365), compares the n and the total number of dots N _d (S36
6), <if N _d, return to S361 in order to perform a series of processing for the remainder of the dot, n> n the process is terminated if it is N _d.

FIGS. 32 and 34 are diagrams for explaining the process of determining the "row" to which each dot belongs based on the data of the dots classified for each column.

FIG. 33 shows a dot pattern.
E ₂₁ indicated by the eij indicated by the "0" dot, "0", e ₂₃
Is a dot, such as "dirt" or "dust", and the standard dot pitch in the vertical (y) direction is P _ey , and the standard dot pitch in the horizontal (x) direction is Pex.

FIG. 34 is a diagram showing a flow of processing for determining a "row". In the first row series search step (S370) in which the first dot in each column belongs to the first row, the first dot is The second row series search step (S371), which is a dot belonging to the second row, the third row series search step (S372), wherein the first dot is a dot belonging to the third row,
In the steps (S370, S371, S372), the row of the leading dot is determined for the remaining columns for which the leading dot cannot be determined to which row (S37).
3) and determining a row for each dot for each column based on the row of the first dot of each column (S374).

In the first row series search step, the dots belonging to the first row are determined. The dot belonging to the first row is the uppermost dot, and the value of the y coordinate is smaller than the other dots. Therefore, the y-coordinate of the first dot in each column is compared, the smallest one is found, and its value is set to E _y1 . Next, the y coordinate E _y (i, i,
j), and E _y (i, j) is within a predetermined range (E _y1 −
_{δ 0y <E y (i,} j) count <E _y1 + δ _0y) Number of dots N _y1 in. N _y1 is within a predetermined range (N _ymin ≦ N _y1 ≦ N
_ymax ), _let E _{y1 be} the representative Y coordinate value of the first row. N
Since _y1 is not in the predetermined range is a strong possibility not dots as the e ₂₁ in FIG. 33, the line number E _s of e ₂₁ (2,1)
= −1, the fact that it is not a dot is stored, and the dot with the second y coordinate of the first dot in the row is searched for, and the process is repeated. In Figure 33, in turn, e ₁₁ are candidates. Therefore, assuming that E _y1 = E _y (1, 1), the number of dots N _y1 whose Y coordinate is within a predetermined range is counted. At this time,
Since there are e ₄₁ and e ₇₁ , N _y1 = 3, and the pattern is repeated three times. If N _ymin = 2 and N _ymaX = 4, N _Y1 is within a predetermined range, so E _Y1 = E _Y (1,1)
And the rows of e ₁₁ , e ₄₁ , and e ₇₁ are determined to be 1, and E _S (1,
1) = E _S (4.1) = E _S (7,1) = 1 is registered.

Here, the row number E _S (i, j) of each dot
Is assumed to be 0. The next step is to determine the dots belonging to the second row. However, the dots in the second row do not have the feature that they are located at the top, unlike the dots in the first row. The dots located below the standard vertical dot pitch _Pey from the representative Y coordinate E _Y1 are
Dots that belong to the line. That is, it is determined that the line has already been determined, or it is not a dot, and E _S (i,
j) The y coordinate E _y (i, j) of the dot excluding the dot where 1 or −1 is E _y1 + P _ey −δ _ey <E _y (i, j) <E _y1 + P _ey + δ _ey When it satisfies, it is determined that it belongs to the second row, and E _s (i, j)
= 2. At this time, E _y (i, j) <E _y1 + P _ey −
The first line in the case of [delta] _ey, do not belong to the second row, since yet is above the second row, which means that there is no belongs rows, E _s
(I, j) = − 1.

In the next search step for the third row sequence, the same processing as the search step for the second row sequence is performed. However, the third
The condition for belonging to a row is: E _y1 + 2 · P _0y −δ _ey <E _y (i, j) <E _y1 + 2 · P
_ey + δ _oy .

If there is no missing in the first to third rows, it is determined which series each column belongs to by the above processing. However, if there is a missing, there are cases where some columns cannot be determined. . This is shown in FIG.

In FIG. 35, “0” is a dot, “+”
Indicates a missing dot, and the numerical value indicates the row number determined in the above-described first to third row series search step. FIG.
5 (a) shows a case where there is no missing, FIG. 35 (b) shows a case where only the first line is missing, FIG. 35 (c) shows a case where only the second line is missing, and FIG. 35 (d) shows a case where only the third line is missing. In case, FIG.
FIG. 35F shows a case where the first and second rows are missing.
FIG. 35 (g) shows the case where the first and third rows are missing.
FIG. 35 (h) shows a pattern when the first row, the second row, and the third row are missing when the row and the third row are missing.

In FIGS. 35B to 35H, FIG.
(B), FIG. 35 (e), and FIG. 35 (h) are not correct rows, but rows are determined for all columns. In this case, the number of missing lines is not a problem because the number of missing lines can be known by the fact that the line number assigned to each dot is smaller than a prescribed value by the number of missing lines. Therefore, only the cases of FIGS. 35 (c), 35 (d), 35 (f) and 35 (g) need to be considered.

In the case of FIG. 35 (c) and FIG. 35 (f), the series on both sides is determined, and the left column is the first row series.
Since the row on the right side is the third row sequence, a column whose sequence is not determined is likely to be the second row sequence. Therefore, using the representative Y coordinate value E _y1 of the first row, the Y coordinate value E _y (i, 1) of the first dot of the column whose sequence has not been determined
Is E _y1 + (1 + 3k) P _ey −δ _ey <E _y (i, 1) <E _y1
K (an integer of 1 or more) that satisfies + (1 + 3k) P _ey + δ _ey is obtained. At this time, since this dot belongs to the (2 + 3k) th row, E _s (i,
j) = 2 + 3k. If k is not determined, row determination for dots in this column is aborted.

In the case of FIG. 35D, the third row series is missing,
In the case of FIG. 35 (g), it is assumed that the second row and the third row are missing, and the Y coordinate value E _y (i, i,
The sequence is determined by j). For the second row line are as defined above, in the case of the third row _{series, E y1 + (2 + 3k} ) P ey -δey <E y (i, 1) <E
When k satisfying _y1 + (2 + 3k) _Pey + _δey exists, the row to which the dot _ei1 belongs is 3
(K + 1) rows.

Since the row numbers are determined at the head dot of each column for at least the effective column by the processing of S370 to S373 in FIG.
The line number is determined using the line number of the leading dot.

FIG. 36 is a view for explaining the processing flow of the "line" determination step (S374) for all dots in FIG.

In order to advance the processing for each column, the column number is initialized to i = 1 (S380), and to proceed from the top of each column, the dot number j is initialized to 1 (S381).

E _s (i, j) is referred to by E _s (i, j) to determine whether the j-th dot in column i is the first dot.
<Because it is O if invalid _{dot, E s (i, j)} = - 1
Then, the dot number j is increased by 1 to determine the next dot (S383). At this time, j is the number of dots N in the row.
_{If G} (i) or less, there is an undetermined dot, and the process returns to the leading dot determination step (S382). If j exceeds _NG (i), all the dots in column i have been determined, and the missing column is processed. In this case, all the dots in this column are invalid dots.

If the first dot is determined in the first dot determination step (S382), the reference Y coordinate E _py and the reference line number S are initialized with the first dot in order to determine the line numbers of the remaining dots (S385). ).

The interval k is initialized to 0, j is incremented by 1 to determine the row number of the next dot (S386), and the dot number is compared with the number of dots N _G (i) of the column i (S38).
7). If j ≦ _NG (i), there is a dot for which the row has not been determined, and the Y coordinate is compared for determining the row (S388). Here, the Y coordinate of the reference dot is E
_{In py} , the vertical direction of each column is every two dots, so the Y coordinate of the next dot is k for the interval and P _{ey for} the standard pitch in the vertical direction.
Then, it is near E _py +3 kP _ey . _{Thus, E ey + 3kP 0y -δ ey} <E y (i, j) <E py + 3kP
_{If ey} + δ _ey , the line of the dot is determined and its line number E
_s (i, j) = S + 3k (S391), and to determine the line number of the next dot, the reference Y coordinate E _py and the reference line number S are used to determine E _py = E _y (i, j). Is updated (S385).

In the Y coordinate comparison step (S388), E
_{py + 3kP oy + J ey <} E y (i, j) in the case of more because it is below the dots, and the distance increases 1 and k = k + 1 (S390) , performs a comparison of Y coordinates (S388).

Also, E _y (i, j) <E _py +3 kP _ey −
In the case of δ _ey , since it is not within the predetermined range, it is determined to be an invalid dot, and E _s (i, j) = − 1 is set (S389), and a row for the next dot is determined (S386).

The row number is sequentially determined within the column, and when the row is determined at the last dot of the column, the dot number comparison step of S387, j> _NG (i), and the row of the next column is determined. to determine a column number is increased 1 (S392), the column number i as compared to the total number of columns N _c (S392), i <performs a series of processes for the remaining rows, if Nc, i> If _Nc , the process ends.

Next, a process for obtaining the above-mentioned grid points from the data of the dots whose “row” and “column” are determined (S317 in FIG. 24).
Will be described with reference to an example of a grid having an indefinite column interval.

Assuming that the column number is i, the dot number in the column is n, and the row number of each dot is j, equations (20), (21), (22), (23)
J = E _s (i, n), P _x (i, j) = E _x (i,
n), P _y (i, j) = E _y (i, n), and the sum of each term of the dot E _s (i, n)> 0 for each column is defined as S _n (i): Number S _J (i): Sum of row numbers (j) S _JJ (i): Sum of j ² S _X (i): Sum of x coordinates S _Y (i): Sum of Y coordinates S _JX (i): Sum of (row number) × (X coordinate) S _JY (i): Sum of (row number) × (Y coordinate) Assuming that (20) to (23),

[0182]

[Outside 22] Can be expressed as

FIG. 37 is a graph showing lattice constants in accordance with equations (20) to (23).

[0184]

[Outside 23] FIG. 7 is a diagram for explaining a flow of a process for obtaining a.

In order to perform the processing sequentially for each column, the column number i =
1 (S400), and sum S of each term in column i
_n (i), S _J (i), S _JJ (i), S _X (i), S
_Y (i), S _JX (i), and S _JY (i) are initialized to 0 (S401).

In order to sequentially add the data of the dots in the row, the dot number n is initialized to 1 (S402), and it is confirmed whether or not the dot ein is a valid dot (S403).

When E _S (i, n)> 0, since the effective dot has a determined row number, the cumulative addition of each term S _n (i) = S _n (i) +1: the number S _J ( _{i) = S J (i)} + E S (i, n): line number _{S JJ (i) = S JJ} (i) + E S (i, n) · E S (i,
n) :( row _{^{number) 2 S X (i) =}} S X (i) + E X (i, n): x -coordinate _{S Y (i) = S Y} (i) + E Y (i, n): y -coordinate _{S JX (i) = S JX} (i) + E S (i, n) · E X (i,
n) :( line number) × _{(x-coordinate) S JY (i) = S} JY (i) + E S (i, n) · E Y (i,
n): (line number) × (y coordinate) If E _S (i, n) < 0, the addition is not performed because it is a valid dot.

In order to add the data of the next dot, the dot number n is incremented by 1 (S405), and the dot number n is compared with the number of dots _NG (i) in the row (S406), and n < _NG.
In (i), there is dot data that has not been added.
Returning to S403, a series of processing is repeated.

[0189] For n> N _G (i), in order to process the next row i = 1 is increased (S407), compared to the total number of columns Nc (S408), if i <N _c treatment Since there is a column that does not end, the flow returns to S401 to perform a series of processing.
In the case of i> N _C , the sum of each term has been obtained for all the columns.

[0190]

[Outside 24] Is calculated.

The process (S318 in FIG. 24) of calculating an evaluation value for discriminating a non-defective / defective product from the dot data in which “row” and “column” are determined and grid point data will be described.

The processing for calculating the evaluation value is described in more detail below.
A shift amount calculating step of calculating a shift of a position of each dot from a grid point, a totaling step of totalizing a shift amount from the grid point and a dot diameter for each row, and an evaluation value calculating step of calculating a final evaluation value Consists of

FIG. 38 is a diagram for explaining a shift amount of a dot from a grid point. In FIG. 38,

[0194]

[Outside 25] The deviation amount d _x (i, j), _dy (i, j) and the dot diameter E
_n (i, j) is tabulated for each row, and the average, standard deviation,
Find the maximum and minimum values. At this time, when the measured values are distributed to the image processing apparatus 1 (111) and the image processing apparatus 2 (112), it is necessary to transfer data for integrating the measured values. Here, if the shift amount and the dot diameter for each dot are directly transferred, the transfer becomes complicated due to a change in the number of dots due to a lack or the like. Sum, sum of squares of measured values,
After calculating the maximum value and the minimum value, this data is transferred. That is, for α of a certain measurement value, the number of dots in the image processing device 1 (111) and the image processing device 2 (112)

[0195]

[Outside 26] Since data transfer can be performed with a fixed length and data can be processed halfway through each device, processing can be performed at a higher speed than directly transferring measured values.

In the process data totaling step (S225 in FIG. 19) of the image processing apparatus 2 (112),

[0197]

[Outside 27] Is calculated, and in the aggregate data transmission step (S226), this data is transmitted to the image processing apparatus 1 (11
Send to 1). On the other hand, after receiving the data from the image processing apparatus 2 (112), the image processing apparatus 1 (111) totals its own data, integrates the quantity data, and integrates the average value, standard deviation, and maximum value for each item. , Find the minimum value.

The average value, standard deviation, maximum value, and minimum value of each measurement item (shift amount, dot diameter) for each row are obtained by the above-described processing, and the evaluation value is calculated using these values.

The first item of the evaluation value is the number of rows N. The number of rows N, for each line number of dots N (j), the number of rows with a predetermined value [delta] _n or dots, in the case of N (j) <δ _n, that line is set to missing. The number of missing rows can be determined from the number of rows N.

The second item of the evaluation value is the dot diameter. This is the average value of the dot diameter for each line

[0201]

[Outside 28]

The third item of the evaluation value is variation in dot diameter. This is the standard deviation σ _r of the dot diameter of each row.
For (j), an average value σ _R = Σσ _r (j) / N and a maximum value σ _Rmax = Max [σ _r (j)] are obtained. Thereby, the stability of the dot diameter can be evaluated.

The fourth item of the evaluation value is an adjacent shift amount. The adjacent shift amount will be described with reference to FIG.
In FIG. 39, d _{1 to} d ₄ and d _{11 to} d ₁₄ are dots, the “+” mark indicates the center position of each dot, and the arrow indicates the amount of deviation from the lattice point. When evaluated by the amount of deviation from the grid point,
FIGS. 39A and 39H show the same shift amount. However, in the actual pattern, the shift amount appears to be larger in FIG. This is because the direction of the deviation of the dot d ₂ and the dot d ₃ is different. That is, in an actual pattern, a shift amount between adjacent dots becomes more problematic than a shift amount from a lattice point.

Therefore, the average value of the shift amount from the grid point for each row

[0205]

[Outside 29] And the maximum value D _xmax = Max [nx (i)], D _Ymax =
Max [ny (i)], minimum value D _Xmin = Min [nx
(I)], and D _Ymin = Min [ny (i)] is obtained. With these, the uniformity of the dot position can be evaluated.

As the fifth item of the evaluation value, there is variation in dot positions. This means that the average value σ _x = Σσ _dx (j) / N, σ _Y = Σσ _dy (standard deviation σ _dx (j), σ _dy (j) of the shift amount of the dot position from the grid point for each row. j)
/ N, maximum value σ _Xmax = Max [σ _dx (j)] σ _Ymax = M
ax [σ _dy (j)] is obtained. Thereby, the stability of the dot position can be evaluated.

As the sixth item of the evaluation value, there is a column maximum deviation amount. This is based on the maximum value and the minimum value of the shift amount from the grid point in the x direction,

[0208]

[Outside 30] Ask by As shown in FIG. 88, this is a value for evaluating the case where the amount of displacement between the adjacent rows is small, but the displacement is seen in the entire column.

[0209] The image processing apparatus 1 (111) calculates the evaluation value as described above and transmits it to the main CPU 100 as a measurement result.

On the other hand, when receiving the measurement result, the main CPU 100 compares the data of each item with a predetermined standard value,
A good product and a defective product are determined.

Next, a dirt detection process using scattered dots as another image processing performed by the image processing apparatus 1 (111) and the image processing apparatus 2 (112) will be described. FIG. 41 shows an example of "dirt" detected by this processing.

In FIG. 41, reference numeral 300 denotes a vertical line pattern, reference numeral 301 denotes a dirt which is connected to the vertical line pattern and has a protruding shape, reference numeral 302 denotes dirt which is separated from the vertical line pattern and is isolated, and reference numeral 303 denotes a vertical line pattern. Is a dirt in which protruding dirt and isolated dirt are present over a wide range. FIG. 41 schematically shows a state in which these dirt-containing patterns are captured as digital images in the image processing apparatuses 1 and 2, and the density values at x = i and y = j are represented by I _{Expressed as p} (i, j).

FIG. 42 is a diagram showing a flow of the dirt detection processing.

In the first step, the digital image I
_This is a step (S500) of obtaining an average density P (x) in the y direction from _p (i, j). P (x) is I where i = x
_p (i, j) is the average value. By this processing, FIG.
(S500).

The second step is a step of obtaining a threshold value T ₁ for generating a binary image from the average density P (x) (S 501). The maximum value Max [P of P (x)
(X)] represents the paper surface density, and the minimum value Min [P (x)] represents the pattern portion density, so that a predetermined value t ₁ satisfying O <t ₁ < ₁
T = Min [P (x)] + t ｛Max [P
(X)] − Min [P (x)]}, a threshold value T for separating the paper surface from the pattern is obtained.

The third step is the second step (S5
The threshold T ₁ determined in 01) binary image Bp (i,
j) is generated (S502).

In the fourth step, the binary image B _p (i,
j) to obtain an edge image E _p (i, j) (S
503). Here, in order to create the edge image E _p (i, j), as shown in FIG.
In three pixels,

[0218]

[Outside 31] Obtained by the following processing. By this processing, an edge image as shown in FIG. 45 is obtained.

[0219] The fifth step is an enlarged edge image E _p,
This is a process (S504) of separating the dirt portion and the pattern by the reduction process. As the enlargement / reduction processing, FIG.
Can be performed by a logical operation process using 3 × 3 pixels as shown in FIG. First, when the enlargement processing is performed on the edge image _Ep (i, j), the line becomes thick as shown in FIG. In FIG. 46, the hatched portions indicate thick lines. Next, when this image is reduced, an image as shown in FIG. 47 is obtained. In this process, the unstained portion returns to the same image as in FIG. 45, but the unstained portion remains as a surface instead of a line as shown by the black portion in FIG.

In the sixth step, the same edge processing as in the fourth step is performed again on the edge image E _p '(i, j) that has been subjected to the enlargement / reduction processing (S505). Since the dirty portion is a surface, an edge is generated between the pattern portion and the dirty portion by the edge processing, and the pattern portion and the dirty portion are separated to obtain an image as shown in FIG.

The seventh step is an edge image E _p ″ (i, j) in which the edge portion = “1” and the surface portion = “0”
Is inverted to generate an image in which the edge portion is “0” and the surface portion is “1”, and the above-described labeling process is performed on the image to obtain a label image L _p (i, j) (S506). FIG.
FIG. 49 is a view schematically showing a state where labels 1 to 8 are attached to FIG. 48.

The eighth step is a step of determining the area of each label (S507). The area S (k) is the pixel where k = L _p (i, j) in the label image L _p (i, j). Is a number. The ninth step is a step (S508) of separating the pattern portion and the dirty portion by the area S (k). Since the area of the protruding dirt and the isolated dirt is much smaller than the area of the pattern, the area of the dirt is S _d (k) and the area of the pattern is S _p (k). _A predetermined value δ _{s such that d} (k) <δ _s ≪S _p (k) can separate the pattern portion and the stain portion.

[0223] Thus, S (k) <number of stains and the number N _d of label satisfying δ _{s, S} (k) <area of the sum S _d dirt S (k) satisfying δ _{s, S} (k) S (k) that satisfies <δ _s
The maximum value S _{maxd of} is _set as the maximum stain, and is used as the evaluation value of the projecting stain and the isolated stain.

The dirt near the pattern such as 303 in FIG. 41 has a small difference in area from the pattern portion as in the label 5 in FIG. 49, so that it is difficult to separate the dirt by area. Therefore, in the tenth step, the average density P in the y direction
The pattern width is obtained from (x), and dirt near the pattern portion is detected (S509).

FIG. 50 shows the average density P (x) when there is a stain near the pattern. When the solid line is dirty,
The dashed line is the case without dirt. If there is dirt, the average density of that part decreases, and when the pattern widths W ₁ and W ₂ are obtained from the threshold value T ₂ close to Max [P (x)], the width W ₁ ′ when there is no density, Wider than W ₂ '. Therefore, the width W is used as an evaluation value of the stain near the pattern.

As described above, by determining the area and the width as evaluation values, it is possible to evaluate dirt.

[0227]

As described above, according to the present invention, an edge image is generated from grayscale image data obtained by automatically reading an evaluation pattern drawn by an output device to be evaluated, and the edge image is generated. After performing the enlargement / reduction process, the edge is extracted again, the shape feature value of each area separated by the contour line of the edge image is obtained, and the pattern and dirt are identified from the shape feature value, and the state of the dirt is determined. Is detected.

Further, one-dimensional average density in the line direction of the pattern is obtained from the grayscale image data obtained by automatically reading the evaluation pattern in which the straight lines are arranged at predetermined intervals on the recording material. The line width in the vicinity of the paper surface density of the recording material is obtained from the distribution state of the average density in the right-angle direction, and dirt is detected based on the line width.

Therefore, the dirt can be quantitatively evaluated, and the evaluation of the output device to be evaluated can be performed accurately and without variation.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a top member of a recording head.

FIG. 2 is a diagram illustrating a silicon plate of a recording head.

FIG. 3 is a diagram illustrating a positional relationship between a silicon plate of a recording head and a top member.

FIG. 4 is a diagram illustrating an overall configuration of a recording head.

FIG. 5 is a diagram showing an arrangement of a printed board.

FIG. 6 is a front view of the print inspection apparatus.

FIG. 7 is a rear view of the work setting mechanism.

FIG. 8 is a view showing a work clamping unit.

FIG. 9 is a diagram showing a recovery mechanism.

FIG. 10 is a diagram illustrating the principle of a recovery process.

FIG. 11 is a view showing a paper transfer mechanism.

FIG. 12 is a diagram showing details of each part of the paper transport mechanism.

FIG. 13 is a view showing another embodiment of the work clamping unit.

FIG. 14 is a block diagram showing a control unit of the inspection device.

FIG. 15 is a flowchart for explaining the operation of the inspection device.

FIG. 16 is a block diagram illustrating details of an image processing apparatus.

FIG. 17 is a diagram illustrating a relationship between a print pattern and an imaging area.

FIG. 18 is a diagram showing the contents of measurement condition data.

FIG. 19 is a flowchart of a measurement process.

FIG. 20 is a diagram showing an ideal dot pattern.

FIG. 21 is a diagram showing a defective dot pattern.

FIG. 22 is a diagram illustrating a tip portion of a recording head.

FIG. 23 is a diagram showing a print pattern in which dots are separated.

FIG. 24 is a flowchart for measuring dot uniformity.

FIG. 25 is a diagram schematically showing an operation in a dot position shape measurement step.

FIG. 26 is a diagram illustrating a process of correcting dot position data.

FIG. 27 is a diagram illustrating grid points in an evaluation value calculation step.

FIG. 28 is a diagram showing a dot data management table.

FIG. 29 is a diagram showing a storage format of dot data.

FIG. 30 is a flowchart of a process for identifying a column to which each dot belongs.

FIG. 31 is a flowchart of a process for rearranging column numbers.

FIG. 32 is a flowchart of a process for identifying a row to which each dot belongs.

FIG. 33 is a diagram showing a dot pattern.

FIG. 34 is a flowchart of a process for determining a row of each dot.

FIG. 35 is a diagram showing a dot pattern.

FIG. 36 is a flowchart of a process of a row determination step.

FIG. 37 is a flowchart of a process for obtaining a lattice constant.

FIG. 38 is a diagram illustrating a shift amount of a dot from a grid point.

FIG. 39 is a diagram illustrating an adjacent displacement amount.

FIG. 40 is a diagram illustrating a shift amount from a grid point in the X direction.

FIG. 41 is a diagram illustrating an example of a pattern including dirt due to scattered dots.

FIG. 42 is a flowchart of a dirt detection process.

FIG. 43 is a diagram showing data in a stain detection process.

FIG. 44 is a diagram for describing processing for obtaining an edge image.

FIG. 45 is a diagram showing an edge image.

FIG. 46 is a diagram showing an image obtained by performing an enlargement process on an edge image.

FIG. 47 is a diagram showing an image obtained by further performing reduction processing after enlargement processing.

FIG. 48 is a diagram illustrating an image obtained by performing edge processing after enlargement, reduction, and processing.

FIG. 49 is a diagram showing a relationship between each region of the image shown in FIG. 48 and a label.

FIG. 50 is a diagram showing an average density when there is a stain near a pattern.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Main CPU 110 CRT 111, 112 Image processing device 801, 802 Imaging device 500 Work set mechanism 600 Recovery mechanism 700 Paper transport mechanism 800 Measurement mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Fumio Ichikawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-3-188357 (JP, A) JP-A-3 JP-A-206945 (JP, A) JP-A-61-6774 (JP, A) JP-A-4-201339 (JP, A) JP-A-4-120448 (JP, A) JP-A-1-279376 (JP, A) JP-A-64-1077 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 29/46 G01N 21/88 G06T 7/00

Claims (8)

(57) [Claims] 1. A predetermined pattern for evaluation is drawn on a recording material by an output device to be evaluated, the drawn pattern is imaged by an image pickup device, and gray image data obtained by the imaging is stored. And generates an edge image of the first
The second edge image is subjected to enlargement / reduction processing to generate a second edge image, and the second edge image is subjected to edge extraction processing to generate a third edge image. A print evaluation method characterized by extracting a shape feature value for each of the separated areas, and determining the quality of the output device to be evaluated based on the shape feature value. 2. The method according to claim 1, wherein before the first edge image is generated, the line width is measured based on the average density, dirt is detected from the line width and the shape characteristic value, and the quality of the output device to be evaluated is determined. The printing evaluation method according to claim 1, wherein 3. The apparatus according to claim 1, wherein the output device to be evaluated is an ink jet type recording head.
Printing evaluation method described in 1. 4. An evaluation pattern in which straight lines are arranged at predetermined intervals is drawn on a recording material by an output device to be evaluated, the drawn pattern is imaged by an imaging device, and gray-scale image data obtained thereby is stored. From the grayscale image data, one-dimensional average density data in the line direction of the evaluation pattern is obtained, and from the distribution state of the average density in a direction perpendicular to the line direction, the evaluation pattern of the evaluation pattern in the vicinity of the recording sheet density A printing evaluation method comprising: measuring a line width of a straight line; and judging the quality of the output device to be evaluated according to the line width. 5. An imaging unit for reading an evaluation pattern drawn by an output device to be evaluated, a storage unit for storing grayscale image data corresponding to the evaluation pattern output from the imaging unit, and the grayscale image data. First edge extracting means for generating a first edge image from the image data; processing means for performing a scaling process on the first edge image to generate a second edge image; On the other hand, a second edge image is generated to generate a third edge image.
Edge extracting means, and calculating means for calculating a shape feature value for each region separated by a contour line in the third edge image, and based on the shape feature value, A print evaluation device for determining pass / fail. 6. The print evaluation apparatus according to claim 5, wherein the output device to be evaluated is an ink jet recording head. 7. An image pickup means for reading an evaluation pattern in which straight lines are arranged at predetermined intervals, drawn on a recording material by an output device to be evaluated, and shading corresponding to the evaluation pattern output from the image pickup means. A storage unit for storing image data, obtaining one-dimensional average density data in a line direction of the evaluation pattern from the grayscale image data, and calculating a density of the recording material from a distribution state of the average density in a direction perpendicular to the line direction. Processing means for obtaining data relating to the line width of a straight line of the evaluation pattern in the vicinity of the paper surface density, wherein the quality of the output device to be evaluated is determined according to the data relating to the line width. Evaluation device. 8. The image evaluation apparatus according to claim 7, wherein the output device to be evaluated is an ink jet recording head.