JPH04338577A - Method and device for evaluating printing - Google Patents

Abstract

PURPOSE:To improve evaluation accuracy by converting a pattern for evaluation drawn by an output equipment to be evaluated into an image data, extracting the quantities of feature of each dot and calculating pattern evaluation values corresponding to the quantities of feature at every dot in the title method of a dot pattern output equipment. CONSTITUTION:A main CPU conducts measurement processing by driving a paper moving stage and image processors 1, 2 while referring to measuring condition data. That is, the image signal of a pattern to be measured is input and the image processors 1, 2 are assigned. The corresponding image processors 1 or 2 performs image inputting and image processing respectively on the basis of the assignment. The processing data of the image processor 2 are tabulated, and transmitted over the image processor 1 and all processing data are tabulated. The uniformity of dots is measured by the image processing, thus evaluating the pattern.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to devices that output dot patterns, such as inkjet recording heads.
The present invention relates to a method and apparatus for evaluating printing.

0002

[Prior Art] Conventionally, when evaluating the quality of recording heads and printer bodies in inkjet printers, etc.,
It has been common practice to draw an evaluation pattern on a predetermined sheet of paper and perform a sensory evaluation based on visual inspection by an inspector. Here, as evaluation patterns, patterns were prepared for each evaluation item that would make it easy for a human to see the difference between good and bad.

0003

[Problems to be Solved by the Invention] However, in the visual sensory evaluation by inspectors, there are variations in the evaluation due to individual differences among the inspectors performing the evaluation and the inability to perform quantitative evaluation.

[0004]Also, in order to eliminate variations in quality due to the current evaluation methods, evaluations using TV images, etc. are attempted, but since there are many inspection items and the amount of patterns for each inspection item is large, it is difficult to perform not only inspection but also However, there is a problem in that it takes time to draw the evaluation pattern itself.

[0005] The present invention has been made in view of the above points.
The purpose is to provide a print evaluation method and apparatus that can eliminate variations in evaluation, enable highly accurate evaluation, and shorten the time required for evaluation.

[0006]

[Means and effects for solving the problem] The present invention draws an evaluation pattern in which dots are arranged so that they do not touch each other on a recording material by an output device to be evaluated, and the drawn evaluation pattern is used by an imaging device. Take an image and convert it to image data,
Extracting a plurality of dot features representing the characteristics of each dot from the image data, calculating a pattern evaluation value representing the state of the pattern according to the dot features of each dot,
A print evaluation method is provided, characterized in that the pattern evaluation value is used to determine the quality of the output device to be evaluated.

The present invention also provides an image input means for capturing an image of an evaluation pattern drawn by an output device to be evaluated and arranged so that dots do not touch each other and converting it into image data;
It has a feature amount extraction means for extracting a dot feature amount representing the feature of each dot from the image data, and a pattern evaluation value calculation means for calculating a pattern evaluation value representing the state of the pattern according to the dot feature amount for each dot. The present invention also provides a print evaluation device characterized in that the quality of the output device to be evaluated is determined using the pattern evaluation value.

According to the present invention, the pattern drawn by the output device to be evaluated is automatically read, the feature amount for each dot is extracted from the read image data, and the feature amount of the output device to be evaluated is extracted based on this feature amount. Evaluate.

[0009]

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

(1) Recording head FIGS. 1 to 5 are diagrams showing the configuration of an inkjet recording head to be inspected in this embodiment, and is of a type that uses thermal energy to eject ink from an ejection port. be.

In the figure, 3001 is a plurality of ejection ports arranged in a linear manner for ejecting ink, and 3002 is a heater arranged for each ejection port, which generates heat when energized and heats the ink to cause film boiling. is caused to eject ink from the ejection port in the P direction. 3003 is a silicon plate on which a discharge port 3001 and a heater 3002 are formed, and 3004 is a top member in which a groove 3005 and a discharge hole are formed for each discharge port. Form an ink flow path. 3006 is an ink tank for supplying ink to the ink flow path. Also 3
007 is an aluminum plate, which fixes the silicon plate 3003 and has reference surfaces 3008a to 3008f for providing positional accuracy with respect to the position of the heater 3002.

Of the reference planes on this aluminum plate 3007,
3008d and 3008f are reference planes with respect to the arrangement direction of the ejection ports 3001 (hereinafter referred to as the X direction), 3008c is a reference plane with respect to the ink discharge direction (P direction) (hereinafter referred to as the Y direction), 3008a, 3008b and 3008e are the above-mentioned, This is a reference plane for a direction perpendicular to a plane formed by the X and Y directions (hereinafter referred to as the Z direction).

Further, 3009 is connected to a printed board fixed to aluminum plate 3008 and silicon plate 3003 by wire bonding 3011. Also printed board 3009
has a pad 3010 on the surface that is contacted by a connector for signals from the main body of the recording device or the main body of the print evaluation device to be described later, and includes a conductor pattern 3012 for connecting between this pad 3010 and a pad for wire bonding 3011. .

Next, the recording head inspection apparatus will be explained.

(2) Main body of the inspection device FIG. 6 is a plan view showing the overall configuration of the inspection device in this embodiment. A recovery mechanism 600 performs a recovery operation for the workpiece, a paper movement mechanism 700 equipped with paper on which a predetermined test pattern is printed by the workpiece, and a measurement mechanism 800 that reads the test pattern from the paper in the movement mechanism 600. Next, each mechanism will be explained.

(a) Work setting mechanism 500 FIG. 7 is FIG.
FIG. 3 is a rear view of the workpiece setting mechanism when viewed from the direction of arrow A in FIG. This will be explained below with reference to FIGS. 6 and 7. 501
is a workpiece clamping unit for clamping a workpiece to be inspected that has been manually set by an operator, and the details will be described later. 502-1 and 502-2 are work fixing parts for fixing the set work W, and are provided on a rotary table 505 that rotates around a shaft 504 by a rotary table rotation drive source 503. The workpiece fixing parts 502-1 and 502-2 each have workpiece fixing arms 521-1 and 521-2 and workpiece fixing jigs 523-1 and 523-2, and the workpiece fixing arm 5
21-1 and 521-2 are workpiece holding members 506-1 and 506-2 for fixing the workpiece W, respectively, and workpieces for electrically connecting the workpiece W and the head driver boards 508-1 and 5082. Connection contact pin 507
-1, 507-2. 509 is a contact pin fixing arm equipped with a contact pin 510 for a rotary table, and a cylinder 51 for vertically driving the contact pin.
1 causes vertical movement along two axes 512 (in the direction of FIG. 7C)
do. Contact pin fixing arm 509 during test printing
is lowered to the position shown by the broken line in FIG. Thereby, the rotary table contact pin 510 is connected to one of the two rotary table contact pin receiving pads 513-1 or 513-2 provided on the rotary table 505, and the driver board 508-1 or 508
-2 to transmit the signal for printing the test pattern. Further, 514 is a tube for supplying air to the cylinder 511 for driving the contact pin up and down, and the contact pin fixing arm 509 moves up and down in response to this air supply. Further, 515 is an air supply solenoid for supplying air to the tube 514.

FIG. 8 shows details of the workpiece clamping unit 501 for fixing the workpiece W. In the figure, 551 is a work fixing arm drive cylinder for driving the work fixing arm 521. It is fixed to a cylinder fixture 552, and when air is supplied, the work fixing arm 521 is driven.
21 is along the workpiece fixing arm drive shaft 530 in the direction (
I direction) and release the clamp on the workpiece W. Further, when the air supply is stopped, the workpiece fixing arm 521 is moved by the spring 527 to the workpiece fixing arm drive shaft 5.
30 in the clamping direction (J direction), and clamps the workpiece W by the workpiece holding member 506-1 and the workpiece connection contact pin 507-1.

553 is a workpiece fixing arm drive cylinder 5
This is an air socket fixing jig having an air socket 554 for the air socket 51. Further, 555 is an air supply port that can be connected to the air receiving port 554, and is movable in the K direction and the L direction by an air supply port drive cylinder 556. 557 is an air supply solenoid for supplying air to the air supply port drive cylinder 556; 558 is a solenoid for supplying air to the fixed arm drive cylinder 551 when the air supply port 555 and air receiving port 554 are in a connected state; Air supply solenoid.

To unclamp the work W, when the rotary table 505 is stopped, an air supply port 555 (described later) is moved in the direction toward the rotary table (K direction) by an air supply port drive cylinder 556, and the air supply port 555 is moved toward the rotary table (direction K).
5 and the air socket 554. Then, air is supplied from the air supply port 555 to the air receiving port 554 on the rotary table 505, and the pressure of this air drives the workpiece fixing arm drive cylinder 551, and the workpiece fixing arm 521 fixed thereto is moved along the drive shaft 530. The clamp is released by moving the clamp. When the rotary table 505 rotates, the air supply solenoid 55
7 to stop the air supply. As a result, the workpiece fixing arm 521 is moved in the J direction by the spring 527 and clamps the workpiece. Thereafter, the air supply port drive cylinder 556 moves the air supply port 555 in a direction away from the rotary table 505 (L direction), and rotates it after leaving the rotary table 505 .

FIGS. 13(a) to 13(c) are diagrams showing the workpiece clamping unit 501 in detail. In the figure, the same members are denoted by the same numbers as in FIGS. 6 and 8. 521 is a work fixing arm that is provided with a work holding member 506-1, a work connection contact pin 507-1, and a drive direction converter 522 and is movable in the direction of arrow D; 523 is a work fixing jig fixed to the rotary table 503; A workpiece holding member 506-1 or 506-2 and a workpiece connection contact pin 507- are provided on the workpiece fixing arm 522 for this workpiece fixing jig 523.
1 or 507-2 presses the workpiece W, the workpiece W is fixed. The drive direction converter 522 is shown in FIG.
), it has a surface oblique to the moving direction of the workpiece fixing arm 522, and a workpiece fixing release cylinder 524 provided on the base allows the driving force transmission lever 525 to move up and down in the direction of arrow E. It can be moved in the direction of arrow D by being pushed by a roller 526 (FIG. 8(c)) provided at the tip. Also, 527 is a work fixing arm 52
The springs 528 and 529 that press 2 are sensors that detect the position of the driving force transmission lever.

Clamping and unclamping of the workpiece W is performed as follows. Normally, when air is not supplied to the workpiece fixing release cylinder 524, the cylinder separates from the driving force transmission lever 525, and the spring 527 works to push the workpiece fixing arm 522 toward the workpiece, thereby causing the workpiece fixing arm 522 to be disposed on the workpiece fixing arm 522. The workpiece holding member 506 and workpiece connection contact pin 507 press against the workpiece W, and the workpiece W is fixed between the workpiece fixing jig 523 and the workpiece holding member 506.

When air is supplied to the work fixing release cylinder 524, the driving force transmission lever 525 attached to the rotary table 505 is pushed, and the roller 526 attached to 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 whose surface that contacts the roller 526 is oblique to the drive direction, and the work fixing arm 522 is moved along the work fixing arm drive shaft 530 to the side opposite to the workpiece W. By moving to , the workpiece holding member 506 and the workpiece connection contact pin 507 are separated from the workpiece W, and the workpiece 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 workpiece unfixing cylinder 524, thereby making it possible to detect the workpiece unclamping position and the workpiece clamping position. There is.

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

(b) Recovery Mechanism 600 FIG. 9 shows details of the recovery mechanism, and FIG. 10 shows the principle of the recovery operation. In the inspection apparatus of this embodiment, after clamping the work W and before test printing, a suction recovery operation is performed on the work W to prevent clogging due to dust or the like. 60
1 is a recovery port that contacts the discharge surface of the workpiece W, 602 is a recovery vacuum pump for sucking ink in the workpiece W from the discharge port, 603 is a recovery mechanism fixing jig, and 604 is a drive shaft for the recovery port 601 606 is a recovery port moving cylinder for moving forward or backward in the direction of arrow F; 605 is an air supply solenoid for supplying air to the recovery port moving cylinder 604; 607 is a recovery port moving cylinder 604 sucked by the recovery vacuum pump 602; This is an ink discharge port for discharging the ink. Further, 608 and 609 are 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 an opening larger than the surface where the discharge ports of the head are lined up and a wall surface smaller than the surface where the discharge ports of the head are lined up. It is a trumpet-shaped member that has a hole for suction in a part thereof, and a tube connected to a recovery vacuum pump 602 is connected to this hole. This recovery port 601 is the recovery port moving cylinder 6
04 and comes into contact with the workpiece, as shown in Fig. 10.
As shown in (b), the tube is sealed except for the hole connected to the recovery vacuum pump 602. When the air in the space A surrounded by the recovery port 601 and the workpiece W is vacuumed by the recovery vacuum pump 602, negative pressure is applied to the hole in the head, and ink is sucked from the ejection port. This makes it possible to immediately print from an ejection port where ink is difficult to eject due to dust or the like.

(c) Paper transport mechanism 700 FIG. 11(a) is a rear view of the paper transport mechanism when viewed from the direction of arrow G, and FIG. 11(b) is a side view of the paper transport mechanism when viewed from the direction of arrow H. It is a diagram.

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

Next, reference numeral 705 is a paper suction jig having a plurality of holes for vacuum on the surface for sliding the paper, the details of which are shown in FIG. 12(d). The plurality of holes 753 are connected to the tube 706 via a ventilation path 754, and are sucked by an air vacuum solenoid 709 to attract paper when printing a test pattern.

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

Further, 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 of winding the paper take-up reel 702 . Even in this state, the brake is applied to the paper supply reel 701 to the extent that it does not rotate. That is, since the felt 752 having soft elasticity is wrapped around the shaft 751 of the paper supply reel 701, a weak brake is applied due to the frictional resistance generated between the inner surface of the paper supply reel, the felt, and the paper supply reel shaft. In this state, tension is applied to the paper and the paper suction jig 7
05 hole 753 to fix the paper. Before the next inspection, a high voltage that overcomes the brake is applied to the motor 702 for a certain period of time to rotate the motor 702 in the paper winding direction and wind the paper. After a certain period of time, a weak voltage is again applied to the motor 702 to stop the paper and vacuum again. The path of the paper is defined by moving along multiple roller axes.

The paper supply unit table 708 includes a vertical drive stage 711 movable in the Y direction, which is provided on a stage fixing table 710 fixed to the moving part of the paper moving stage 712.
The paper suction jig 705 can be moved in the vertical direction. This is necessary when measuring a printed test pattern at high magnification, as will be described later.

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

In this 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 with a different magnification.

For example, in order to measure the landing position of a droplet emitted from each nozzle, it is necessary to measure the position of a dot printed by each nozzle with a resolution of about 5 μm. At this time, the measurement area is a 2.5 mm aperture (with 500 x 500 pixels), and the measurement system or printed paper is moved four times to measure the landing position of the droplet by a head with a 10 mm nozzle length. Moreover, the image must be processed.

In addition, when measuring density unevenness in the nozzle arrangement direction for different patterns using the same optical system, the resolution is 25 μm.
m, so the measurement area is 12.5 mm (pixel 5).
00x500), and for this test it is 1
A head with a nozzle length of 0 mm can be measured in one go. Therefore, in order to shorten the measurement time, it is better to arrange a plurality of two-dimensional imaging devices each having an optical system with the necessary magnification for measurement.

In this embodiment, the imaging device 801 has a high-magnification optical system and is used to inspect the deviation (deviation) of the droplet landing position. Further, the imaging device 802 has a low magnification optical system,
Used to inspect density unevenness in the nozzle arrangement direction.

(3) Control Section FIG. 14 is a block diagram showing the control section of the inspection apparatus in this embodiment. In the figure, 100 is the main CPU, and RO
It has M, RAM, etc., and controls each part of the inspection apparatus main body according to a program to be described later. 101 is a rotary table controller 113 that controls the rotational drive of the rotary table 505 and a cylinder 51 for vertically driving the contact pins.
This is an interface that sends a control signal from the main CPU 100 to the air supply solenoid 515 for supplying air to the main CPU 100. 102 is the main CP for the air supply solenoids 557 and 558 in the work clamp unit.
This is an interface that sends control signals from U100. 103 is the air supply solenoid 6 in the recovery mechanism 600
Main C for 05 and recovery vacuum pump 602
This is an interface that sends control signals from the PU 100. This is an interface that sends control signals from the main CPU 100 to the paper winding motor 703 in the paper transport mechanism 700 and the air vacuum solenoid 707 for paper suction. A stage driver 105 sends a drive signal from the main CPU 100 to a paper supply unit drive motor 709 and a paper movement motor 712 in the paper transport mechanism 700.

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

Reference numeral 109 denotes an operation unit equipped with various keys such as a start key 120, and key input signals are input to the main CPU 100 via the interface 108. Again 1
10 is a CRT for displaying test results and the like.

The main CPU 100 also receives output signals from various sensors provided in the work setting mechanism 500, the recovery mechanism 600, and the paper transport mechanism 700, and the main CPU 100 controls each part based on these sensor output signals. Performs operation control.

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

FIG. 15(a) is a flowchart showing the basic operation flow of the inspection apparatus in this embodiment. First, the rotary table 505 is rotated (step 100).
). Then, wait for the operator to replace the workpiece W at the workpiece fixing part (502-1 in FIG. 6) (step 20).
0) When the workpiece exchange is completed, the recovery mechanism 600 performs recovery processing on the workpiece W (step 300). After the recovery process, the rotary table 505 is rotated again and the workpiece W is set at a printing position facing the roll paper (step 400). Then, a predetermined test pattern is printed, and the roll paper on which the test pattern has been printed is moved by the paper transport mechanism 700 to a measurement position, and is measured by the imaging devices 801 and 802.
1, 112, predetermined processing for inspection is performed (step 500). The measurement results are then displayed on the CRT 110 (step 600).

The above is the basic flow of operation, but since this embodiment has two workpiece fixing parts on the rotary table, the measurement and result display processing for the workpiece fixed to one workpiece fixing part is performed. While this is being done, it is possible to perform workpiece conversion and recovery processing on the other workpiece fixing section. In this embodiment, the flow of operation is shown in Figure 1.
5(b).

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

Each operation will be explained below with reference to FIGS. 15(c) to 15(f). Here, the operation when using the workpiece clamping unit shown in FIG. 8 will be explained.

(a) Two workpiece fixing parts 502- of the rotary table 505 for workpiece exchange processing
1 and 502-2, the main CPU 100 activates the air supply solenoid 557 via the interface 102 in order to release the workpiece clamping state of the workpiece fixing part (502-1 in FIG. 6) that is farther from the paper transport mechanism 700. the air supply port 5 is turned on, and the air supply port drive cylinder 556 closes the air supply port 5.
55 is moved forward (in the K direction) to connect it with the air socket 554 (step 201). When the sensor 559 detects that the air supply port 555 moves forward and connects with the air socket 554 (step 202), the air supply solenoid 55
8 to supply air to the fixed arm drive cylinder 551, move the workpiece fixing arm 521 in the unclamping direction (I direction) until the sensor 561 turns on, and then press the workpiece holding member 506 and the contact pin 50 for connecting the workpiece.
7 away from the workpiece W after the inspection (step 203,
204). Then, a workpiece exchange message is displayed on the CRT 110 (step 205).

After the operator sees this and takes out the workpiece after the inspection and inserts the uninspected workpiece into the gap between the workpiece fixing arm 521 and the workpiece fixing jig 523, the start switch 120 on the operation section 109 is turned on. (steps 206, 207).

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

Here, the workpiece connection contact pin 50
7 is connected via a cable to a contact pin receiving pad 513 for the rotary table through a driver board 508, and this receiving pad 513 is connected to the contact pin fixing arm 5 by a cylinder 511 for vertically driving the contact pin.
09 descends, the contact pin fixing arm 509
A rotary table contact pin 510 attached to the end face of the rotary table contacts the receiving pad 513.

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

Furthermore, as the contact pin vertical drive cylinder 511 rises, the rotary table contact pin 510 attached to the end face of the contact pin fixing arm 509 separates from the receiving pad 513, and the rotary table 505 is prevented from rotating. It makes it possible.

(b) Recovery Process The workpiece W is moved to a recovery process after being clamped. Main CPU1
00 turns on the air supply solenoid 605 via the interface 103, and moves the recovery port 601 forward to contact the discharge surface of the workpiece W by the recovery port moving cylinder 604 (step 301). When the sensor 608 detects that the recovery port 601 has moved to a position where it contacts the discharge surface of the workpiece W, the main CPU 100
3, and the recovery vacuum pump 602 vacuums the air in the space A (FIG. 10) surrounded by the recovery port 601 and the workpiece W for a certain period of time (steps 303, 304). As a result, the ink in the workpiece W is flushed out from the ejection port, thereby performing a recovery operation. The ink that has been scooped out from the work is in the recovery port 6.
01, the ink passes through a tube, a recovery vacuum pump 602, and is discharged from an ink discharge port 607.

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

(c) Rotation processing of the rotary table The main CPU 100 turns on the air supply solenoid 515 via the interface 101 to drive the cylinder 511 for vertically driving the contact pin, and the contact pin fixing arm is moved until the sensor 516 turns on. 509 is raised (steps 101, 102). As a result, the rotary table contact pin 510 provided on the end surface of the contact pin fixing arm 509 separates from the rotary table contact pin receiving pad 513.

After that, the main CPU 100 controls the rotary table controller 113 via the interface 101.
Outputs a control signal to rotate the rotary table. This allows rotary table controller 1
13 turns on the rotary table drive source 503 to rotate 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 completion signal for the previous workpiece is output from the image processing devices 111 and 112 via the interfaces 106 and 107. Under this condition, the air supply solenoid 515 is turned off and the contact pin fixing arm 509 is lowered by the contact pin vertical driving cylinder 511 until the sensor 517 is turned on (steps 104 and 105). This brings the rotary table contact pin 510 and the rotary table contact pin receiving pad 513 into a connected state.

(d) Measurement Process After the rotation process of the rotary table, the main CPU 100 drives the paper moving stage drive motor 713 for a certain period of time via the stage driver 105 to move the paper moving stage 712 in the M direction (FIG. 6). , the print position of the workpiece W is set a predetermined distance (50 mm in this example) from the paper suction jig 705 M
(Step 501)
, 502).

Then, the data stored in the RAM in the main CPU 100 is output to the stage driver 113 via the interface 113, and the paper moving stage drive motor 713 is driven, so that the paper moving stage 712 moves at a speed of 300 m/s.
Imaging device 801 with high magnification optical system at EC speed
Move it until it reaches the position. The main CPU 100 detects the signal from the sensor 770 that turns on when the interleaving sheet suction jig 705 reaches the printing position, and the driver board 50
8 and sends a print signal to the ROM in the driver board 508.
Print the pattern according to the contents of (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 certain period of time (steps 505, 506). And when the movement is completed, main C
The PU 100 sends a control signal to start measurement to the image processing devices 111 and 112 via the interfaces 106 and 107. After receiving this signal, the image processing devices 111 and 112 perform a plurality of tests described below, and send the completion signal and the results to the main CPU 100 via the interfaces 106 and 107. The main CPU 100 displays the results on the CRT 110 and notifies the operator (steps 507 to 509).

When the main CPU 100 receives a signal from the stage driver 113 indicating that the paper moving stage 712 has come to rest at the measurement position of the imaging device 801, the main CPU 100 rotates the rotary table 505.

In the above embodiment, the workpiece W was replaced manually by the worker, but it is also possible to replace the workpiece W automatically using an automatic hand. In this case, the main CPU 100 is connected to the auto hand via a cable via an interface, and when the work is exchanged, the main CPU 100 sends a conversion start signal to the auto hand control to start the work exchange, and when the exchange is finished, the auto hand controller sends the conversion start signal to the main CPU 100. sends an exchange end signal to

Further, in the above embodiment, the paper moving stage is moved during printing to print the test pattern, but the structure may be such that the paper is fixed and the workpiece is moved to print the test pattern. good.

[0063] Similarly, the imaging device may also be configured to be moved when reading the test pattern.

Further, in this embodiment, an inkjet recording head that ejects ink using thermal energy is used as an example of the recording head to be inspected, but the present invention is not limited to this, and for example, piezo elements may be used. The ink may be ejected using pressure energy such as an electromechanical transducer such as the above. Alternatively, a recording head of a thermal recording method using thermal paper or an ink sheet may be used.

(5) Contents of Inspection Next, the contents of the processing performed by the image processing devices 1 and 2 (111, 112) will be explained in detail.

(a) Configuration of image processing devices 1 and 2 FIG. 16 shows image processing device 1 (111) and image processing device 2 (1
12) is a block diagram of the image processing device.

In FIG. 16, 181 is a ROM in which a startup program for the device is stored; 182 is a RAM in which an execution program is temporarily stored or used by the execution program;
184 is an FDD (floppy disk drive) which is an external storage device for recording execution programs and parameters;
183 is the FDC (floppy disk controller) that controls the FDD 184 of 184, and 185 is the main CPU
188 is a serial I/O such as RS-232C that communicates with 100 and input/output devices such as CRT 110 and operation unit 109, and 188 is between image processing device 1 (111) and image processing device 2 (112). GP that communicates large amounts of data in
Parallel I/O such as IB, 189 is the above-mentioned imaging device 80
1 (hereinafter referred to as camera 1) and an imaging device 802 (hereinafter referred to as camera 2) and input them into digital image signals, or input the digital image signals to monitor TV 190.
193 is an image memory that stores digital image signals; 194 is a binarization processing unit that converts the grayscale image signal into a binary image signal; 195 is a unit that numbers connected areas and identifies the area. Label processing unit that enables
Reference numeral 6 denotes a feature calculation unit that calculates features for each area in the image, and each unit is connected to the image CPU 18 via a system bus 197.
Controlled by 0. Also, an image input/output section 189, an image memory 193, a binarization processing section 194, a label processing section 19
5. Transfer of image data between the feature value calculation units 196 is performed at high speed via the image bus 198.

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

210 is pattern 1a and pattern 1b of 211, pattern 2a of 212 and pattern 2b of 213,
The pattern 3a of 214 and the pattern 3b of 215 are the same patterns, but the relative movement directions of the head (work W) and the roll paper during pattern formation are different. That is, 2
Pattern 1a of No. 10, pattern 2a of No. 212, and pattern 3a of No. 214 are forward printing, and pattern 1b of No. 211 is printing.
, 213, pattern 2b, and 215, pattern 3b are backward printing.

Among these patterns, pattern 1 is the paper moving stage 7 for measurement by the TV cameras 1 and 2.
Of the 12 reciprocating movements, measurements are performed twice each on the outward and return journeys, pattern 2 is measured once each on the outward and return journeys, and pattern 3 is measured once each on the reciprocating and return journeys. In addition, patterns 1 and 2 use a TV camera 1 with a high-magnification optical system to perform high-intensity measurements.
The image is taken twice in the Z direction, and for pattern 3, the image is taken once using the TV camera 2 with a low magnification optical system in order to grasp the entire pattern. Therefore, there are 14 imaging 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.

[0072] The main CPU 100 stores measurement condition data 2.
50, commands are sent to the paper moving stage 712, image processing device 1 (111), and image processing device 2 (112) to perform measurement processing.

The measurement condition data 250 includes an imaging area number 251 for identifying the imaging area, and a pattern to be measured on the TV.
Stage 71 for moving paper to bring it into the field of view of cameras 1 and 2
2 moving positions 252(1) and 252(2), image processing device numbers 253 and 221 that specify the image processing device that inputs and processes the image signal of the pattern to be measured, imaging areas 1 and 2
area connection data 254(1), 254(2) for identifying that the 22 imaging areas 2 are connected; pattern number 2 for identifying a pattern and processing accordingly;
55 and printing direction 256 are stored for each imaging area in accordance with the order of measurement processing. In addition, after the final imaging area, data indicating the end of the measurement condition data (
Imaging area number)=-1 is stored.

(c) Measurement Processing FIG. 19 is a diagram showing the flow of measurement processing. Hereinafter, a case where measurements are performed according to the contents of the measurement condition data 250 will be described as an example.

First, the main CPU 100 reads data 250(1) regarding the first imaging area of the measurement condition data 250.
with reference to the position data of the paper moving stage 712
00, Y=100, and based on this data, a movement command is issued to the stage drive motor 713 for paper movement, and the process waits for the movement to be completed (S201). Next, measurement condition data 2
50(1) and moves to the process (S203 or S205) corresponding to the image processing device number (S202). At this time, if data indicating an image processing device that does not exist is stored (in this example, a value other than 1 or 2 is stored), it means that no measurement is performed at this position, and the remaining data will be explained later. Area confirmation step (S2
07).

In this embodiment, since the image processing device number is 2, an image input command is sent to the 108 image processing device 2 to input a pattern image (S205).
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 device. Whether or not the current area is the final area of each image processing device can be confirmed by referring to the image processing device number 253 of the measurement condition data 250 for the current area and beyond.

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

[0078] Here, based on measurement conditions means, for example,
In order to select the optical system that matches the target pattern (in this example, the pattern number is 1, so the high magnification optical system is selected), the camera input of the image processing device 2 (112) is switched. . At this time, the combination of pattern number and optical system is set in the image processing apparatuses 1 and 2 in advance.

When the image signal input is completed, the image processing device 2 (112) transmits an image signal input completion signal to the main CPU 100 (S222). Main CPU
100 receives the image signal input completion signal from the image processing device 2 (112) (S206) and moves to the step of confirming the remaining measurement area (S207).

In the step of confirming the remaining measurement area (S207), the imaging area number of the next measurement condition data 250(2) is referred to, and it is confirmed whether the data is the finished data or not. This means that an unmeasured area remains, so the stage movement step (S201)
Return to and refer to the next measurement condition data 250(2). Execute stage movement (S201) and measure condition data 2
When referring to the image processing device number 253 in 50(2), the image processing device number is 1, so the image processing device 1
For (111), image signal input command, measurement condition data,
transmitting the final area information, confirming the reception of the image signal input completion signal from the image processing device 1 (111) (S204),
A remaining measurement area confirmation step (S207) is performed. When the image processing device 1 (111) receives an image signal input command from the main CPU 100 (S210), the image processing device 2
Image signals are input (S211) in the same way as in the image input step (S221) of (112), and the main CPU 100
Sends an image signal input completion signal to (S212)
. When the image processing devices 1 and 2 transmit the image signal input completion signal to the main CPU 100, they perform image processing corresponding to each pattern as described later (S213, S223), and determine whether the current area is the final area or not. Confirm based on the final area information (S214, S224), and if it is not the final area (2
In 50 measurement condition data, imaging area number: 1 to 1
2), the image signal input receiving step (S210,
Returning to S220), in the case of the final region (imaging region numbers: 13 and 14 in measurement condition data of 250), measurement data aggregation processing (S215 to S217, S22
5 to S226).

[0081] The operation of the aggregation process is performed by the image processing device 1 (11
1) and the image processing device 2 (112) are different. In the image processing device 2 (112), the image processing step (S223
) is totaled for each measurement item (S225), and the image processing device 1 (111) transmits the data when it becomes able to receive the total data, and after the data transmission is completed, the data is stored in the memory. After making preparations for the next measurement such as initialization, the process returns to the image signal input receiving step (S220) (S226). On the other hand, in the image processing device 1 (111),
First, total data from the image processing device 2 (112) is received (S215), and then data calculated within the image processing device 1 (111) is totaled, and the data calculated within the image processing device 1 (111) is totaled.
2) to calculate the final measurement result (S216).

[0082] As soon as the measurement results are calculated, the main CP
Send the measurement results to U100, prepare for the next measurement such as initializing the memory, and proceed to the image signal input step (S21).
0) (S217).

[0083] When the main CPU 100 determines that there is no remaining area in the remaining area confirmation step, the main CPU 100 is in a state of waiting for reception of the measurement results, so as soon as the measurement results are calculated by the image processing device 1 (111), Receive the results (S2
08), the measurement process is finished and the process moves on to the comparison process with the next standard value, etc.

(d) Image processing Next, image processing device 1 (111), image processing device 2 (11
The image processing performed in 2) will be explained in detail.

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

The first image processing measures the uniformity (position and shape) of dots. The pattern in Figure 20 is
This is an ideal pattern, and the pattern shown in FIG. 21 includes non-uniform dots. In FIG. 21, part (a) shows the case where the dot positions are shifted left and right, and the straight line pattern is no longer straight. Part (b) shows the case where the dots are shifted vertically, and the connected straight lines cut them. Part (c) shows a case where the position of the dots fluctuates up and down, and the straight line is disturbed. Part (d) shows a case where the size of the dots is non-uniform, and the line width varies. Part (e) shows the case where the size of the dot is small, and the straight line is straight, but the line width is narrow.

[0087] When the dots become non-uniform in this way, the print pattern is disturbed.

FIGS. 22 and 23 are diagrams illustrating printing patterns used in the first image processing.

FIG. 22 is a diagram showing the tip of the recording head (work W). At the tip of the recording head, a plurality of holes (nozzles) 201 for ejecting ink are lined up in the Y direction.
A printing pattern is formed on the roll paper by relative movement of the paper moving stage 712 and the recording head in the X direction.

FIG. 23 is a diagram showing a print pattern, which is an object to be inspected, printed on a roll paper by a recording head. Here, the dot di,j is output by the nozzle 201(i), and if the Y direction (nozzle arrangement direction) is a column and the X direction (head movement direction) is a row in FIG. The dots dp,j to which it belongs belong to the same nozzle 201 (
The dots formed by p) and belonging to the qth column are dots formed by a plurality of nozzles at approximately the same time during the relative movement of the print head.

[0091] The spacing between each dot is set so that adjacent dots do not touch each other, and in this embodiment, every two nozzles are simultaneously printed in each column, and the spacing between each column is also set to be the same. There is.

By using such a pattern, each dot is separated, so it becomes possible to measure the position and shape of each dot.

FIG. 24 is a diagram showing the flow of the first image processing, in which steps after the image processing step of FIG. 19 (S211 to S2
17, S223 to S226) in detail.

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.
S303 in FIG. 4, S216 and S225 in FIG. 19 are S304 in FIG. 24, and S217 and S226 in FIG. 19 are S3 in FIG.
05 respectively.

S301 in FIG. 24 is a step of measuring the position and shape data of each dot, which is the basic data of this process, and the step of measuring according to the coordinate system within each area (S311) and the positional relationship of each area. The process includes a step (S313) of calculating position data in which the position of the paper moving stage 712 at the time of imaging is corrected in consideration of the above.

[0096] In S304 of FIG. 24, the position and
This is a step of converting the measured value calculated in the shape measurement step (S301) into an evaluation value for ultimately determining good products and defective products, and each dot corresponds to which "row" in FIG.
a step of identifying whether it belongs to a “column” (S316);
A step (S317) of calculating the position of each dot point by least squares approximation and calculating the positional deviation of each dot from the difference between the grid point position and the position of each dot (S317), and calculating the data of each dot for each nozzle (Fig. 23 (S318) for calculating the evaluation value.

FIG. 25 is a diagram schematically showing the operation of the dot position/shape measurement step (S311) in FIG. 24.

FIG. 25(a) is a digital image of the pattern to be measured stored in the image memory 193, and each numerical value indicates the density value at each pixel.

FIG. 25(b) is a binary image separated into a dot portion and a background portion by density value threshold processing. Here, threshold processing is the original image

[0100]

[Outside 1] The output image is obtained by the following formula for

[0101]

[Outside 2] This is the process of creating .

[0102]

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

If the threshold value T is a fixed constant, the separation of dots and background will become unstable due to fluctuations in the amount of illumination light, etc. Therefore, the number of pixels with the same density is counted from the original image I and a density histogram is created. When FIG. 25(d) is created and the lowest density value is Min, the highest density value is Max, and the number of pixels at a certain density i is G(i), the following formula is used.

[0104]

(4) Using Min' and Max' that satisfy the following, T is determined by the following formula.

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

Here, t is a fixed value, but since Min' and Max' follow variations in the amount of illumination light, etc., a binary image that is stable against variations is output.

FIG. 25(c) is a label image in which each dot of the binary image of FIG. 25(b) is given a separate number so that each dot can be identified. To create a label image, 2
When the value image Bp(x,y) is scanned in the order of TV raster scanning and the target pixel Bp(x,y)>0, the image shown in FIG.
The surrounding four pixels (Pi-1, j-1, P
i, j-1, Pi+1, j-1, Pi-1, j), and if there is a pixel that already has a label value, that value is set as the label value of Pij, and the pixel with the label value is If there is no pixel, a new label value that has not yet been used is set as the label value of Pij. Furthermore, in the case of the part (f) in FIG. 25(b), two different label values exist for the reference pixel. In this case, remember that the two labels are the same label, and correct it after one scan is completed. A label image Lp(x,y) is obtained through such processing.

Next, from the label image Lp(x,y), the moment feature amount Mp for each label is expressed by the following formula.
Find q(k).

[0109]

[Outer 5]

In this moment feature, M00(k) is the area of label K, M10(k)/M00(k) is the x-coordinate of the center of gravity, and M01(k)/M00(k) is the y-coordinate of the center of gravity. It represents. Therefore, the position and shape of each dot can be measured by determining the moment feature amount.

FIG. 26 is a diagram for explaining the correction of dot position data. Reference numeral 240 denotes the first imaging area, which is located above the area in which the target pattern was imaged twice (imaging areas 1, 3, 5, and 5 in FIG. 17). 7, 9, 11) area,
241 is the lower side (imaging areas 2, 4, 6, 8, 1 in FIG.
0 and 12) area. Paper movement stage 7
The relative movement command value from the imaging position of the first imaging area 240 of No. 12 to the imaging position of the succeeding imaging area 241 is

[0112]

[6], and the measured value of dot dij in the first imaging area 240 is

[0113]

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

[0114]

[Example 8] Then, if the paper moving stage 712 moves as instructed,

[0115]

[Example 9] However, in reality, it depends on the linearity of the drive system, backlash, etc.

[0116]

[Example 10] occurs. Therefore, the first imaging area 240 and the subsequent imaging area 241 are set to partially overlap, and the two measured values of the dots in the overlapping area are

[0117]

[Outer 11]

[0118] In addition, in order to identify which dot in the first imaging area 240 is the same as which dot in the subsequent imaging area 241, since the interval between each dot is about 200 μm, Dot dij and
L between the dots dst measured in the subsequent imaging area 241
as a predetermined value (~100μm)

[0119]

[Outer 12] When this holds true, dij and dst are considered to be the same dot.

In this way, after converting the measured value of the latent image capturing area 240 and the measured value of the succeeding image capturing area 241 into values of the same coordinate system, measurements are performed in both the leading image capturing area 240 and the succeeding image capturing area 241 in the overlapping area. Among the measured values of the dots, the measured values in one area are deleted and stored in the memory 193.

[0121] In this embodiment, the measured values of the subsequent imaging area 241 are adjusted to the coordinate system of the leading imaging area 240, but the opposite correction may be made. Furthermore, in this embodiment, since the first imaging area 240 is measured first, this correction is performed at the same time as the subsequent imaging area 241 is imaged and the position of each dot is measured, but the imaging order is reversed. In this case, “
It is sufficient to perform this immediately before the step of identifying rows and columns (S316).

[0122] Furthermore, it goes without saying that the division of the area is not limited to two divisions.

Next, the lattice points which are the basis of the evaluation value calculation step (S304 in FIG. 24) for determining good products and defective products will be explained.

[0124] In FIG. 27, "○" indicates an actual dot,
"●" are grid points obtained by calculation, and similarly to FIG. 23, the arrangement in the i direction is called a "row" and the arrangement in the j direction is called a "column."

Here, in the case of an ideal printing pattern, each "
The spacing between rows and columns is constant, and each column and row can be expressed using vectors.

[0126]

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

More specifically, each “
If you know the “row” and “column”,

[0128]

[Outside 14] As, the least squares normal equation is

[0129]

[Outside 15] So, by transforming this,

[0130]

[Outer 16] Therefore, when evaluating a single head,

[0131]

All you have to do is solve H+1 equations simultaneously. When we transform the expression (11) by changing the form of expression, we get

[0132]

[Example 18], the number of dots in the i-th column is N(i), and the sum of j is J
(i), equations (12) and (13) are

0133
]

Expressing this as [Example 19] and substituting this into equations (14) and (15), we get

[0134]

[Outside 20] is obtained, and from this

[0135]

[Outside 21] can be found, so the lattice points with undefined "column" spacing can be found.

Next, step (S3) of the aggregation process in FIG.
The actual operation of 04) will be explained in detail.

FIGS. 28 and 29 are diagrams showing the storage format of dot data obtained in the dot position/shape measuring step (S301). The dot data includes the X coordinate (Xij), Y coordinate (Yij), and dot diameter (
Rij) are stored as a set and the number of dots in the area,
After that, data for the next area is stored in a similar format. However, dots whose area does not fall within a predetermined range are determined to be "dirt" or "dust" rather than dots, and are not stored. The dot diameter Rij is determined by the dot position/routine measurement step (S3
From the dot area (Sij) obtained in 01), Rij
= equivalent diameter calculated as 2√Sij/π.

[0138] Since the dot data is stored consecutively for each area, the imaging area number (Pi) of each area,
The number of dots (Ni) and the starting value of the data storage address (
Ai) are grouped and stored 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. By storing data in this format, memory can be used efficiently even if the total number of dots changes.

[0139] Also, the input command receiving step (S
210, S220), the measurement condition data received from the main CPU 100 is stored, and the connection relationship of each imaging area is obtained using this measurement condition data and the dot data management table, and the "row" of each dot is determined for each connection area. Identify “columns”, calculate grid points, and calculate evaluation values.

[0140] In this example, the dot diameter Rij was determined from the area, but in the dot shape measurement step, the circumferential length Lij was determined from (circumference) = π x (diameter).
It may also be determined by =Lij/π.

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

In FIG. 30, first, target dot=1
, the number of columns Nc is initialized to 0 (S330), and then the number i of the column to be compared is initialized to 1 (S331). column number i
and the number of columns Nc (S332), and if i<Nc, the representative X coordinate value Gx(i) of column i is compared with the X coordinate value Xk of the target dot (S333). At this time, Gx(i
) and Xk is larger than the predetermined value δx, dot k
Since it is far from column i, it is determined that it does not belong to this column, and in order to compare with the next column, i is incremented by 1 (S334), and the process returns to checking the number of columns (S332).

On the other hand, the difference between Gx(i) and Xk is a predetermined value δX
If it is smaller, it is determined that dot k belongs to this column, the X coordinate (XK), Y coordinate (YK), and dot diameter (RK) of dot k are called, and the number i of this column is stored (S33
6). Then, the representative X coordinate of the column is updated with XK, the number of dots belonging to that column is increased by 1 (S337), and then the dot number k is incremented by 1 (S338), and if the target dot still remains (S339 ), comparison with column (S331
).

When the number of columns is checked in S332, if i>NC, it means that there is no column to which dot k belongs, so the column is increased by 1, NC=NC+1, i=NC, and a new The number of dots in the column GN(i) is initialized to 0 (S335), and the dot data storage step (S3
36).

When this series of processes is applied to all dots, a number is assigned to the column to which each dot belongs, but this number is independent of the order in which they are actually lined up. For example, Figure 23
In the case of , 1 to 3 are added in the 1st, 4th, and 7th columns,
Numbers 4 and 5 are assigned to the second and fifth columns, and numbers 6 and 7 are assigned to the third and sixth columns. This is because processing is performed in the order of TV raster scanning when measuring dot positions, and dot data is stored in that order. Therefore, it is necessary to rearrange the column numbers assigned in the process of FIG. 30 so that they match the pattern.

FIG. 31 is a diagram illustrating a flow of processing for sorting column numbers from the left side in the imaging area.

In S340, the new column number k=1 and the number of valid columns Nc' used for subsequent processing are initialized to the current total number of columns Nc. The number i of the column to be compared is 1, and the minimum value Xmin of the representative X coordinate values of the column is set to a large value (for example, Xmin=999
) (S341), and compares Xmin with the representative value Gx(i) of the X coordinate of column i (S342). At this time, 0<
If Gx(i)<Xmin, column i is on the left side of Xmin, so update Xmin=Gx(i), store column number i as Imin (S343), and increase the number of the column to be compared by 1. (S344), and compares the total number of columns Nc (
S345), if i<Nc, there are still columns to compare, and the process returns to S342. If i>Nc, the comparison with all columns has been completed, so the column stored in Imin at this time becomes the k-th column from the left. Next, in order to determine whether the column Imin is a valid column, the number of dots Gx(
Imin) is compared with predetermined values N1, N2 (N1<N2) (S346), and if N1<Gn(Imin)<N2, it is determined to be a valid column, and the number of columns k minus the number of invalid columns is added to the conversion table. (Nc-Nc') as G(Imin)=k-(Nc
-Nc'), and the sign is inverted to Gx(Imin)=-Gx(Imin) so that this data is not used in subsequent processing (S347).

On the other hand, Gn(Imin)<N1 or N2
If <Gn (Imin), there is a strong possibility that it is a column other than dots due to stains, etc., so that column is considered an invalid column and the column number G
(Imin) = 0 is registered in the conversion table, the sign of Gx (Imin) is inverted as in the case of valid columns, and the number of valid columns Nc' is decreased by 1 so that Nc' = Nc' - 1 ( S350).

[0149] When the registration in the conversion table is completed, the new column number k is incremented by 1 to determine the next column (S348),
Compare the new column number k with the total number of columns Nc (S349), and k
If <Nc, there remains a column for which a new column number has not been determined, so the process returns to S341 and repeats the series of processes.

In the case of k>Nc, new column numbers have been determined for all columns, so using the conversion table G(i), DG(i)=G(DG(i))(i=1, 2,...,N
c) Update the column number. Further, the total number of columns is also updated by the number of columns Nc' excluding invalid columns, so that Nc=Nc'.

FIG. 32 is a diagram illustrating a flow of processing in which columns are determined and dot data is stored in each column according to the y-coordinate of the dot in order to identify which row each dot belongs to.

[0152] In the initialization step S360, the number of processed dots NG(i) to NG(Nc) for each column is set to 0,
Target dot No. Let n=1.

Next, the column number of dot n is i (i=DG(n
)), and the number of processed dots NG(i) in column i is increased by 1. At this time, the storage location j of dot n is the NG(i)th data storage area of column i (S361).

[0154] Here, before storing the dot data,
The y coordinate Ey (i, j-1) of the j-1st dot data stored in the data storage area of column i and the y of dot n
The coordinates Dy(n) are compared (S362) and Ey(i,j-
1) If > Dy(n), dot n is above the dot stored in the j-1th area, so move the j-1st data to the j-th area, In order to shift the storage location of dot n up by 1, j=j-1 is set (S363), and the process returns to the y-coordinate comparison step of S362.

[0155] The step of comparing the y coordinate (S362) and the step of moving the stored data (S361) are
)<Dy(n), dot n
All the data of the dots placed lower are shifted one area later, and the area where the data of dot n should be stored becomes empty, so the data of dot n is stored in this area (S3
64).

[0156] After that, increase the target dot number n by 1 (
S365), compare n with the total number of dots Nd (S366)
, n<Nd, the process returns to S361 to perform a series of processes for the remaining dots, and if n>Nd, the process ends.

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

FIG. 33 is a diagram showing a dot pattern.
eij indicated by "0" is a dot, e21, e2 indicated by "0"
3 is "dirt" or "dust" etc. that is not a dot,
The standard dot pitch in the vertical (y) direction is Pey, and the horizontal (x
) The standard dot pitch in the direction is Pex.

FIG. 34 is a diagram showing the flow of processing for determining a "row", in which the first row series search step (S370) in which the first dot in each column is a dot belonging to the first row; A second row series search step (S371) in which the dot belongs to the second row, a third row series search step (S372) in which the first dot is a dot belonging to the third row, and the above 3
In steps (S370, S371, S372), a step (S373) of determining the row of the first dot for the remaining columns in which it was not possible to determine which row the first dot belongs to
, and a step (S374) of determining a row for each dot in each column using the row of the first dot in each column as a clue.

In the first row series search step, dots belonging to the first row are determined. The dots belonging to the first row are the uppermost dots and have smaller y-coordinate values than other dots. Therefore, the y coordinates of the first dots in each column are compared, the smallest one is found, and that value is set as Ey1. Next, the y-coordinate Ey(i,
j), and if Ey(i,j) is within a predetermined range (Ey1
-δ0y<Ey(i,j)<Ey1+δ0y) The number Ny1 of dots is counted. Ny1 is within the specified range (Ny
min≦Ny1≦Nymax), let Ey1 be the representative Y coordinate value of the first row. If Ny1 is not within the predetermined range, there is a strong possibility that it is not a dot like e21 in Figure 33, so set the row number Es (2, 1) = -1 for e21, remember that it is not a dot, and change the column. The y coordinate of the first dot is 2
Find the smallest one and repeat the process. Figure 33
In this case, e11 becomes a candidate. Therefore, E
Assuming y1=Ey(1,1), count the number Ny1 of dots whose Y coordinate is within a predetermined range. At this time, e41, e71
Therefore, Ny1=3, and the pattern is repeated 3 times, so if Nymin=2 and NymaX=4, NY1 is within the predetermined range, so EY1=EY(1,
1), set the rows e11, e41, and e71 to 1, and set E
Register S(1,1)=ES(4.1)=ES(7,1)=1.

Here, the line number ES (i, j) of each dot
It is assumed that the initial value of is 0. The next step is to determine the dots that belong to the second row, but since the dots in the second row do not have the characteristic of being located at the top like the dots in the first row, The dots located below the standard vertical dot pitch Pey from the representative Y coordinate EY1 are defined as dots belonging to the second row. In other words, the line has already been determined, or it is determined that it is not a dot and ES(i
, j) = 1 or -1, the y coordinate Ey (i, j) of the dots is Ey1 + Pey - δey <
When Ey(i,j)<Ey1+Pey+δey is satisfied, it is determined that it belongs to the second row, and Es(i,j)=2. At this time, if Ey(i,j)<Ey1+Pey-δey, it does not belong to the first or second row, and is above the second row, so it means that there is no row to which it belongs, and Es(i,
j)=-1.

The search step for the next third row series also performs the same processing as the search step for the second row series. However, the third
The condition for belonging to a row is Ey1+2・P0y−δey<
Ey(i,j)<Ey1+2·Pey+δoy.

[0163] If there are no omissions in the first to third rows, the series to which each column belongs will be determined by the above processing, but if there are omissions, there may be columns for which the series cannot be determined. . The situation is shown in FIG.

[0164] In FIG. 35, "0" is a dot, "+"
indicates a missing dot, and the numerical value indicates the line number determined by the above-described search step for the series of the first to third lines. Figure 3
5(a) is when there is no deletion, FIG. 35(b) is when only the first row is missing, FIG. 35(c) is when only the second row is missing, and FIG. 35(d) is when only the third row is missing. In the case, Fig. 35(e
) is when the first and second rows are missing, FIG. 35(f) is when the first and third rows are missing, and FIG. 35(g) is when both the second and third rows are missing. FIG. 35(h) shows a pattern when the first, second, and third rows are missing.

In FIGS. 35(b) to (h), FIG.
b), FIG. 35(e), and FIG. 35(h) are not correct rows, but rows are determined for all columns. In this case, there is no problem with the number of missing lines because the number of missing lines can be determined by the line number attached to each dot being less than the specified value by the number of missing lines. Therefore, FIG. 35(c), FIG.
5(d), FIG. 35(f), and FIG. 35(g).

In the case of FIGS. 35(c) and 35(f), the series on both sides have been determined, and the left column is the first row series,
Since the row on the right is the third row series, the columns whose series has not been determined are likely to be the second row series. Therefore, using the representative Y coordinate value Ey1 of the first row described above, the Y coordinate value Ey(i,1) of the first dot of the column whose series has not been determined is calculated.
is Ey1+(1+3k)Pey−δey<Ey(i,1
)<Ey1+(1+3k)Pey+δey. At this time, this dot belongs to the (2+3k)th row, so Es(i,j
)=2+3k. If k cannot be determined, row determination for this column of dots is discontinued.

In the case of FIG. 35(d), the third row series is missing,
In the case of FIG. 35(g), it is assumed that the second and third row series are missing, and the Y coordinate value Ey(i, j
) determines the series. The case of the second row series is as described above, and the case of the third row series is Ey1+(2+3k)Pey−δey<Ey(i,1)
When k that satisfies <Ey1+(2+3k)Pey+δey exists, the row to which dot ei1 belongs is 3(k+1) rows.

[0168] Through the processing of S370 to S373 in FIG. 34, at least for valid columns, the first dot of each column is
Since the line number has been determined, the line number for the remaining dots is determined using the line number of the first dot.

FIG. 36 is a diagram for explaining the processing flow of the "row" determination step (S374) for all dots in FIG. 34.

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

In order to determine whether the j-th dot of column i is the first dot, Es(i,j) is referred to and Es(i,j
)<O, it is an invalid dot, so Es(i,j)=-
1, and the dot number j is incremented by 1 to determine the next dot (S383). At this time, j is the number of dots in that column NG (
If it is less than i), there are undetermined dots, so the process returns to the first dot determination step (S382). If j exceeds NG(i), all dots in column i have been determined, so the missing columns are processed. In this case, all dots in this column are invalid dots.

[0172] If it is determined that the first dot is the first dot in the first dot determination step (S382), the reference Y coordinate Epy 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 NG(i) in that column i (S38
7). If j≦NG(i), there is a dot whose row has not been determined, so the Y coordinates are compared to determine the row (S388). Here, the Y coordinate of the reference dot is E
In py, each row is every 2 dots in the vertical direction, so the Y coordinate of the next dot is determined by setting the interval to k and the standard pitch in the vertical direction to P.
If it is ey, it is around Epy+3kPey. Therefore, Eey+3kP0y−δey<Ey(i,j)<Ep
If y+3kPey+δey, the row of that dot is determined and its row number Es(
i, j)=S+3k (S391), and in order to determine the row number of the next dot, the reference Y coordinate Epy and the reference row number S
is updated to Epy=Ey(i,j) using this dot (S385).

[0174] In the Y coordinate comparison step (S388), E
If py+3kPoy+Jey<Ey(i,j),
Since it is a lower dot, increase the interval by 1 and make k = k
+1 (S390), and the Y coordinates are compared (S388).

[0175] Also, Ey(i,j)<Epy+3kPe
In the case of y-δey, since it is not within the predetermined range, it is determined to be an invalid dot and Es (i, j) = -1 (S389).
, determines the next dot line (S386).

Row numbers are sequentially determined within a column, and when the row is determined at the last dot in the column, in the dot number comparison step of S387, j>NG(i), and the row of the next column is determined. To determine this, the column number is incremented by 1 (S392), the column number i is compared with the total number of columns Nc (S392), and if i<Nc, a series of processes are performed on the remaining columns, and if i>Nc, then If so, end the process.

Next, the process of finding the aforementioned grid points from the dot data for which the "row" and "column" have been determined (FIG. 24S317)
will be explained using a lattice with indefinite column spacing as an example.

If the column number is i, the dot number in the column is n, and the row number of each dot is j, then the (
j = Es (i, n), Px (i, j) = Ex (i, n
), Py(i,j)=Ey(i,n), and the sum for each term of dots with Es(i,n)>0 for each column is S
n(i): Number of dots SJ(i): Sum of line numbers (j) SJJ(i): Sum of j2 SX(i): Sum of x coordinates SY(i): Sum of Y coordinates SJX(i) : Total sum of (line number) x (X coordinate) SJY(
i): (row number) x (Y coordinate), then the (2nd
0) to (23) are,

[0179]

[Outer 22] It can be expressed as

FIG. 37 shows the lattice constants according to equations (20) to (23).

[0181]

[Outer 23] FIG. 2 is a diagram illustrating a flow of processing for determining

[0182] In order to process each column in order, column number i=
1 (S400), and the sum Sn(i
), SJ(i), SJJ(i), SX(i), SY(i
), SJX(i), and SJY(i) are initialized to 0 (S
401).

[0183] In order to sequentially add the data of the dots in the column, the dot number n is initialized to 1 (S402), and the dot e
It is confirmed whether in is a valid dot (S403).

If ES(i,n)>0, it is a valid dot whose row number has been determined, so the cumulative addition Sn of each term is
(i)=Sn(i)+1: Number SJ(i)=SJ(i)+ES(i,n): Line number SJ
J(i)=SJJ(i)+ES(i,n)・ES(i,
n): (line number) 2 SX (i) = SX (i) + EX (i, n): x coordinate SY
(i)=SY(i)+EY(i,n):y coordinate SJX(
i)=SJX(i)+ES(i,n)・EX(i,n)
: (line number) x (x coordinate) SJY(i)=SJY(i)+ES(i,n)・EY(
i, n): (row number) x (y coordinate). If ES(i,n)<0, it is a valid dot and no addition is performed.

[0185] 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 that column (S406), and n<N
If G(i), there is data of dots that have not been added, so the process returns to S403 and the series of processes is repeated.

If n>NG(i), increase i by 1 to process the next column (S407), compare it with the total number of columns Nc (S408), and if i<Nc, end the process. Since there are columns that are not filled in, the process returns to S401 and a series of processing is performed. In the case of i>NC, since the sum of each term for all columns has been found, the lattice constant can be calculated using equations (20) to (23).

01
87]

[Outside 24] Calculate.

The process (S318 in FIG. 24) of calculating evaluation values for determining good products and defective products from the dot data and grid point data whose "rows" and "columns" have been determined will be described.

[0189] In more detail, the process of calculating the evaluation value is as follows:
A deviation calculation step that calculates the deviation of the position of each dot from the grid point, an aggregation step that aggregates the deviation amount from the grid point and the dot diameter for each row, and an evaluation value calculation step that calculates the final evaluation value. Consists of.

FIG. 38 is a diagram illustrating the amount of deviation of dots from grid points. In FIG. 38,

0191
]

[25] The deviation amounts dx(i,j), dy(i,j), and dot diameter En(i,j) are totaled for each row, and the average value, standard deviation, maximum value, and minimum value are determined. At this time, when the measured values are dispersed between the image processing device 1 (111) and the image processing device 2 (112), it is necessary to transfer data in order to integrate the measured values. If we directly transfer the amount of deviation and dot diameter for each dot, the transfer will be complicated due to fluctuations in the number of dots due to omissions, etc., so first, we will transfer the number of dots and measured values for each line in each image processing device. After calculating the sum, the sum of the squared values of the measured values, and the maximum and minimum values, this data is transferred. That is, for a certain measurement value α, the number of dots in image processing device 1 (111) and image processing device 2 (112) is

[0192]

Since data can be transferred in a fixed length, the data can be processed by distributing it to each device up to the middle, which allows faster processing than directly transferring measured values.

[0193] In the processing data aggregation step (S225 in FIG. 19) of the image processing device 2 (112), the above-mentioned

0194
]

[Example 27] is performed up to the step of calculating the total data (
In S226), this data is sent to the image processing device 1 (111).
). On the other hand, after receiving the data from the image processing device 2 (112), the image processing device 1 (111) aggregates its own data, integrates the quantitative data, and calculates the average value, standard deviation, and maximum value for each item. , find the minimum value.

[0195] Through the above processing, each measurement item (
Since the average value, standard deviation, maximum value, and minimum value of the deviation amount and dot diameter are obtained, the evaluation value is calculated using these values.

The first item of the evaluation value is the number of lines N. The number of rows N is the number of rows in which the number of dots in each row N(j) is greater than or equal to a predetermined value δn, and if N(j)<δn, the row is determined to be missing. The number of missing lines can be determined from the number of lines N.

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

[0198]

[Outside 28]

The third item of evaluation value is the variation in dot diameter. This is the standard deviation of the dot diameter of each row σr
For (j), the average value σR=Σσr(j)/N and the maximum value σRmax=Max[σr(j)] are determined. This allows the stability of the dot diameter to be evaluated.

[0200] The fourth item of the evaluation value is the amount of adjacency deviation. The amount of adjacent deviation will be explained using FIG. 39. In FIG. 39, d1 to d4 and d11 to d14 are dots, the "+" mark represents the center position of each dot, and the arrow represents the amount of deviation from the grid point. When evaluated by the amount of deviation from the lattice point, FIGS. 39(a) and 39(h) have the same amount of deviation. However, in the actual pattern, the amount of deviation appears to be larger in FIG. 39(a). This is because the directions of deviation of the dots d2 and d3 are different. That is, in an actual pattern, the amount of deviation between adjacent dots is more important than the amount of deviation from a grid point.

[0201] Therefore, the average value of the amount of deviation from the grid point for each row

[0202]

[29] and maximum value Dxmax=Max[nx(i)], DY
max=Max[ny(i)], minimum value DXmin=M
in[nx(i)], DYmin=Min[ny(i)
] Find. From these, the uniformity of dot positions can be evaluated.

[0203] The fifth item of the evaluation value is the variation in dot positions. This is based on the standard deviations σdx(j) and σdy(j) of the deviation amount of the dot position from the grid point for each row, the average value σx=Σσdx(j)/N, σY=Σσ
dy(j)/N, maximum value σXmax=Max[σdx(
j)] σYmax=Max[σdy(j)]. This allows the stability of dot positions to be evaluated.

The sixth item of the evaluation value is the maximum column shift amount. This is calculated from the maximum and minimum deviations from the grid point in the x direction,

[0205]

Obtained by [30]. This value is used to evaluate a case where the amount of deviation between adjacent columns is small, but there is a deviation when looking at the entire column, as shown in FIG.

The image processing device 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, upon receiving the measurement results, the main CPU 100 compares the data for each item with predetermined standard values, and
Distinguish between good and defective products.

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

In FIG. 41, 300 is a vertical line pattern, 301 is a protruding stain connected to the vertical line pattern, 302 is an isolated stain separated from the vertical line pattern, and 303 is a vertical line pattern. It is a stain that has protruding stains or isolated stains over a wide area near the area. Further, FIG. 41 schematically shows how a pattern containing these stains is taken into the image processing devices 1 and 2 as a digital image, and the density value at x=i, y=j is expressed as Ip. It is expressed as (i, j).

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

[0211] The first step is to create a digital image Ip(i
, j) to obtain the average density P(x) in the y direction (S500). P(x) is Ip(i
, j). Through this process, one-dimensional data as shown in FIG. 43 is obtained (S500).

[0212] The second step is a step (
S501). The maximum value of P(x) Max[P(x)
] represents the paper surface density, and the minimum value Min[P(x)] represents the pattern area density, so using a predetermined value t1 where O<t1<1, T=Min[P(x)]+t{Max[P (x)
]−Min[P(x)]}, a threshold T that separates the paper surface and the pattern is obtained.

[0213] The third step is the second step (S5
01), the binary image Bp(i,
j) (S502).

[0214] In the fourth step, the binary image Bp(i,j
) to obtain the edge image Ep(i,j) (S5
03). Here, to create the edge image Ep(i,j), a 3×3 image centered on the pixel of interest as shown in FIG.
In a pixel,

[0215]

It is obtained by the following process. Through this processing, an edge image as shown in FIG. 45 is obtained.

[0216] The fifth step is to enlarge the edge image Ep,
A process that separates dirt areas and patterns through reduction processing (
S504). Enlargement and reduction processing can be performed by logical operation processing using 3×3 pixels as shown in FIG. First, when the edge image Ep(i,j) is enlarged, the line becomes thicker as shown in FIG. In FIG. 46, the hatched portion indicates a thicker line. Next, when this image is subjected to reduction processing, an image as shown in FIG. 47 is obtained. With this process,
The clean areas return to the same image as in FIG. 45, but the dirty areas remain as surfaces instead of lines, as shown in black in FIG. 47.

In the sixth step, the same edge processing as in the fourth step is again performed on the edge image Ep' (i, j) that has been subjected to the enlargement and reduction processing (S505). Since the soiled portion is a surface, an edge is generated between the pattern portion and the soiled portion by edge processing, and the pattern portion and the soiled portion are separated to obtain an image as shown in FIG. 107.

[0218] The seventh step is to obtain an edge image Ep'' (i, j) in which the edge portion = "1" and the surface portion = "0".
is inverted to generate an image in which the edge portion = "0" and the surface portion = "1", and the above-described labeling process is performed on the image to obtain a labeled image Lp(i,j) (S506). FIG. 49 is a diagram schematically showing how labels 1 to 8 are attached to FIG. 48.

The eighth step is to calculate the area for each label (S507), where the area S(k) is the number of pixels such that k=Lp(i,j) in the label image Lp(i,j). be. The ninth step is that by the area S(k),
Step of separating the pattern part and the dirty part (S508)
It is. The areas of protruding dirt and isolated dirt parts are much smaller than the area of the pattern part, so the area of the dirt part is Sd(k), and the area of the pattern part is Sp(k).
Then, the pattern portion and the soiled portion can be separated by a predetermined value δs such that Sd(k)<δs<<Sp(k).

Therefore, the number Nd of labels satisfying S(k)<δs is the number of stains, and S(k) satisfying S(k)<δs
The total sum Sd is the area of dirt, and S(k) satisfies S(k)<δs.
The maximum value Smaxd of k) is taken as the maximum stain and is used as an evaluation value for protruding stains and isolated stains.

[0221] It is difficult to separate dirt near a pattern such as 303 in FIG. 41 based on area, as the difference in area from the pattern part is not large, as in label 5 in FIG. 49. Therefore, in the 10th step, the average concentration P(
The pattern width is determined from x) and dirt near the pattern portion is detected (S509).

FIG. 50 shows the average density P(x) when there is dirt near the pattern. When the solid line is dirty,
The broken line is the case without stains. When there is dirt, the average density of that part decreases, and when the pattern widths W1 and W2 are calculated using the threshold value T2 close to Max[P(x)], they are compared to the widths W1' and W2' when there is no darkness. The width expands. Therefore, this width W is used as an evaluation value of dirt near the pattern.

As described above, dirt can be evaluated by determining the area and width as evaluation values.

[0224]

[Effects of the Invention] As described above, according to the present invention, a drawn pattern is automatically read, the feature amount of each dot is extracted, a pattern evaluation value is determined from this dot feature amount, and the pattern evaluation value is Since the quality of the output device to be evaluated is determined based on this, quantitative evaluation can be performed and quality can be stabilized.

Furthermore, by extracting a plurality of dot features from one pattern, it is possible to shorten the time required for evaluation.

[Brief explanation of 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 the positional relationship between the silicon plate and the top member of the recording head.

FIG. 4 is a diagram showing the overall configuration of a recording head.

FIG. 5 is a diagram showing the arrangement of printed boards.

FIG. 6 is a surface view of the print inspection device.

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

FIG. 8 is a diagram showing a workpiece clamping unit.

FIG. 9 is a diagram showing a recovery mechanism.

FIG. 10 is a diagram explaining the principle of recovery processing.

FIG. 11 is a diagram showing a paper transport mechanism.

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

FIG. 13 is a diagram showing another embodiment of the workpiece clamping unit.

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

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

FIG. 16 is a block diagram showing details of the image processing device.

FIG. 17 is a diagram illustrating the 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 measurement processing.

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 showing the tip of the recording head.

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

FIG. 24 is a flowchart for measuring dot uniformity.

FIG. 25 is a diagram schematically showing the operation in the dot position and shape measuring step.

FIG. 26 is a diagram illustrating correction processing of dot position data.

FIG. 27 is a diagram illustrating lattice 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 processing for identifying the column to which each dot belongs.

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

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

FIG. 33 is a diagram showing a dot pattern.

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

FIG. 35 is a diagram showing a dot pattern.

FIG. 36 is a flowchart of processing in a row determination step.

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

FIG. 38 is a diagram illustrating the amount of deviation of dots from lattice points.

FIG. 39 is a diagram illustrating the amount of adjacent deviation.

FIG. 40 is a diagram illustrating the amount of deviation from the lattice point in the X direction.

FIG. 41 is a diagram illustrating an example of a pattern including stains caused by scattered dots.

FIG. 42 is a flowchart of dirt detection processing.

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

FIG. 44 is a diagram for explaining 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 enlarging 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 showing an image obtained by further performing edge processing after enlargement, reduction, and processing.

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

FIG. 50 is a diagram showing the average density when there is dirt near the pattern.

[Explanation of symbols]

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 Measuring mechanism

Claims (11)

[Claims] Claim 1: An evaluation pattern in which dots are arranged so that they do not touch each other is drawn on a recording material by an output device to be evaluated, and the drawn evaluation pattern is imaged by an imaging device and converted into image data, and the A plurality of dot feature values representing the characteristics of each dot are extracted from the image data, a pattern evaluation value representing the state of the pattern is calculated according to the dot feature amount of each dot, and the pattern evaluation value is used to calculate the evaluation target. A printing evaluation method characterized by determining the quality of output equipment. 2. The print evaluation device according to claim 1, wherein each dot has a plurality of dot feature amounts. 3. The print evaluation method according to claim 1, wherein a center position of a dot is used as the dot feature quantity. 4. The print evaluation according to claim 1, wherein the dot feature amount is a deviation amount from an ideal position, which is a difference between an ideal dot position and an actual dot position. Method. 5. The output device to be evaluated has a plurality of elements for outputting dots, and the ideal dot position is a grid point position determined from the dot spacing in the arrangement direction of the elements by the least squares method. The print evaluation method according to any one of claims 1 to 4, characterized in that: 6. The print evaluation method according to claim 3, wherein a center of gravity position is used as the center position of the dot. 7. The print evaluation method according to claim 1, wherein a diameter of a dot is used as the dot characteristic amount. 8. The diameter of the dot is an equivalent dot diameter calculated from the area of the dot.
Print evaluation method described in . 9. The print evaluation method according to claim 1, wherein the output device to be evaluated is an inkjet recording head. 10. Image input means for capturing an image of an evaluation pattern arranged so that the dots drawn by the output device to be evaluated do not touch each other and converting it into image data, and a dot feature amount representing the feature of each dot from the image data. and a pattern evaluation value calculation means that calculates a pattern evaluation value representing the state of the pattern according to the dot feature amount of each dot. A printing evaluation device characterized by determining the quality of equipment. 11. The print evaluation apparatus according to claim 9, wherein the output device to be evaluated is an inkjet recording head.