JPH09277670A - Printer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable printer device which rapidly detects print defects attributed to a printing head such as a black band streaker in adequate and simple manner and thereby rejects defective printed matter to perform precise and high-quality printing. SOLUTION: A non-printed area extraction part 260 extracts a blank area not covered with print image data in a printing paper 800, based on input print image data stored in a print image storage part 240. An image reading part 400 reads an image printed in the printing paper 800 by a printing part 200 and stores it in a checked image storage part 460. A checking part 500 scans an area corresponding to the non-printed area of the checked image data in an auxiliary scan direction to detect continuous clack pixels. When the black pixels are found continuous, the checking part 500 interprets that the continuous black pixels represent a black band streaker and as such, a printing head functions abnormally to generate print defects, and immediately stops a printer device 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer device for printing image data sequentially input on a medium such as printing paper at high speed.

[0002]

2. Description of the Related Art As a method of recording predetermined information on a medium such as paper in a visually recognizable manner, a printing plate is used to record the same contents at a high speed in a large amount, or a computer is used. There is known a method of printing arbitrary data on a relatively small number of media at low speed by using a printer used as a terminal device. There is also a desire to print documents that have a large printing volume and require printing different numbers and contents, such as stock certificates, various cash vouchers, or a large number of invoices for many customers. There is also a high-speed printer device for that purpose.

Such a printer device for printing variable data at a high speed has a conveying means for conveying a print medium at a high speed, a printing means for recording an image on a sheet conveyed by the conveying means at a high speed, and a sequentially input printing. It is composed of a control unit or the like that appropriately controls data so that it is appropriately printed on paper. As the printing means, for example, a method of printing by an inkjet method with an inkjet head is applied. As such a high-speed printer apparatus for performing printing by the inkjet method, for example, an apparatus for performing printing at a speed of 5 m / sec and 15 or more sheets / second for A4 size printing paper has been put into practical use.

By the way, in such an ink jet type printer device, although high speed printing is possible, there is a problem that printing defects called streakers such as ink drops and white spots are likely to occur. Since these are problems inherent in the ink jet system and are basically difficult to solve, in such a printer device, the state of the print head substantially determines the print quality. Therefore, in order to prevent defective prints from being output to the outside in such a printer device,
It is necessary to inspect the print result by some method.

[0005]

However, in such a printer device up to now, the inspection can be performed only by visual inspection by an operator or by using a cue mark or the like to inspect a positional deviation of printing. However, there was no means to properly and automatically inspect the print results. Therefore, particularly in the high-speed printer device as described above, if the operator is late to notice the occurrence of the printing defect, a huge amount of defective printed matter is created, and a large amount of printing resources are wasted, which is time-consuming. In addition, there is a problem that the printing cost rises due to a huge loss in cost. Further, in such a printer device, it is difficult to distinguish the black band striker from the ruled line because the print content is different for each printed matter, and the inspection must be performed at the same speed as printing. There were problems, and it was difficult to establish an appropriate automatic inspection method.

Therefore, it is an object of the present invention to detect a printing defect caused by a print head such as a black band streaker at a high speed by an appropriate and simple method, thereby eliminating defective prints and performing accurate and high-quality printing. To provide a highly efficient printer device.

[0007]

In order to solve the above problems, an image printed on a print medium is read by a sensor, and a non-printing area where the original print image does not exist is scanned to print a black striped streaker or the like. Detected defects. Therefore, from the input image data,
The non-printed area is sequentially extracted.

Therefore, the printer device of the present invention has a head portion capable of high-speed printing such as an ink jet method, and print means for printing input image data on a medium, and an image on the printed medium. The non-printing area where printing is not supposed to be performed is scanned by the image sensor means for reading in and the head portion of the read image, and for example, it is inspected whether there is ink dripping by checking the presence or absence of black pixels. And an inspection means for doing so.

In order to carry out the inspection accurately and efficiently, it is important to determine where the non-printing area is. As a preferred example of the printer device of the present invention, the non-printing area is extracted. It has a non-printing area extracting means.
Preferably, the non-print area extracting unit refers to the input image data and extracts a so-called blank area on the print medium that is not covered by the image data as the non-print area. More preferably, the non-printing area extracting means analyzes the data content of the input image data, detects a blank area having a certain extent in the image data, and further detects the blank area. Extract as a non-print area.

Specifically, the inspecting means inspects whether or not there is a succession of black pixels in the sub-scanning direction in the non-printing area of the printing medium, thereby determining whether or not a black band streaker has occurred. To inspect. Preferably, the inspection means extracts the structural features of the read image, and refers to the format information of the original image data to inspect whether or not the extracted features are appropriate, so that the printing is appropriate. Further inspection to see if it has been done. More preferably, the inspection means template-matches the input image data and the read image, and further inspects whether or not printing is properly performed based on the difference between them.

More specifically, in the printer device of the present invention, when the inspection means determines that the printing state is inappropriate, the printing is immediately stopped. Further, specifically, in the printer device of the present invention, when the printing state is determined to be inappropriate by the inspection unit, printing that substantially invalidates the printing is further printed on the printing medium. It has a second printing means.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a printer apparatus of the present invention will be described with reference to FIGS. The printer device according to the present embodiment is a large-scale printing system that prints print data input from a host computer at high speed by using a plurality of inkjet heads. It is possible to detect the defective printing due to.

FIG. 1 shows a printer device 1 according to this embodiment.
It is a schematic external view of the main body, (A) is a side view, (B) is the top
FIG. As shown in FIG.
Printer unit 1a, back printer unit 1b, and paper conveyance
It has a section 110. In addition, the paper transport unit 110 is a roll
Paper supply unit 110_-1, The front seal included in the front printer unit 1a
Printing unit Paper transport unit 110 _-2And table inspection section paper transport
Unit 110_-3, Paper reversing unit 110_-7, Back pre
Backside printing unit paper transport unit 11 included in the center unit 1b
0_-FourAnd back inspection unit paper transport unit 110_-Five, And
And roll paper take-up unit 110_-6It is composed of

In the printer device 1 having such a configuration, the continuous printing paper 800 is supplied from the roll paper supply unit 110 _-1 , the front printer unit 1a prints on the surface of the paper 800, and the paper reversing unit 110 is used. _-7 for that paper 8
00 is reversed, printing is performed on the back side of the sheet 800 by the back printer unit 1b, and the printing is performed on both sides of the sheet 811.
0 _-7 is wound up on the roll paper winding unit 110 _-6 . The printer device 1 includes a control unit and an operation unit (not shown) that are housed in separate housings, apart from the main body whose appearance is shown in FIG. Have.

The configuration of each part of the printer device 1 will be described below. First, the paper transport unit 110 is a paper transport mechanism for stably transporting the print paper 800, which is the print medium, at a high speed and at a predetermined speed. The printer device 1 according to the present embodiment has a printing paper 80 in which continuous paper is wound in a roll shape.
Double-sided printing is performed on 0. Therefore, the paper transport unit 1
10 is a roll paper supply unit 110 _-1 , which supplies roll paper,
The print heads 220a _-1 , 220a _{-2 of the} front printer unit 1a
Front printing paper transport unit 11 that transports printing paper underneath
0 _-2 , CCD camera 440a _-1 , 4 of the front printer unit 1a
40a _-2 front inspection unit paper transport unit 110 _-3 for transporting printing paper underneath, paper reversing unit 110 _-7 for inverting the front and back of printing paper 800, print heads 220b _-1 , 220b _-2 under back printer unit 1b CC of the back printing unit paper transport unit _110-4 and the back printer unit 1b
D camera 440b _-1, 440b _-2 back checking unit sheet conveying unit 110 _-5 for conveying the printing paper under and roll paper take-up unit 110 that takes successively up the discharge print sheets
_-6 is integrally connected.

Each unit is composed of a roller and a guide for feeding the printing paper, an encoder for detecting the rotation speed of the roller, and the like. Based on a control signal input from a control unit (not shown), the printing paper is conveyed and stopped. Adjust speed, etc.
Further, as shown in FIG. 1B, an encoder 111 is provided on the paper feed roller near the beginning of the front printing unit paper transport unit 110 _-2 , and the pulse from this encoder 111 changes the timing of printing. The generated signal is used in each unit of the printer device 1. Further, the printing paper 800 supplied from the roll paper supply unit 110 _-1, immediately after being supplied to the printing unit 200, cue mark is printed by the cue mark printing unit (not shown). After that, each head, camera, and the like, which will be described later, detect the cue mark by a cue mark detection sensor provided in the vicinity thereof, and position the print sheet 800 in the sub-scanning direction. The sheet conveying unit 110 according to the present embodiment is 3 m /
The printing paper 800 is conveyed in about s.

Front printer section 1a and back printer section 1b
Respectively print on the front surface or the back surface of the printing paper 800. Since the front printer unit 1a and the back printer unit 1b have the same configuration, only the configuration of the front printer unit 1a will be described here. FIG. 2 is a block diagram showing the configuration of the front printer unit 1a. The front printer unit 1a includes a paper transport unit 110a, a printing unit 200, and a print image storage unit 24.
0, interface section 250, non-print area extraction section 26
0, image reading unit 400, inspection image storage unit 4
60, a monitor 470, an inspection unit 500, a control unit 600, and an operation unit 610.

The paper conveying unit 110a is a surface printing unit paper transporting unit 110 _-2 and table check section sheet conveying unit 110 _-3 paper transport unit 110 described above, the printing unit of the front printer unit 1a 200 and the image reading unit At 400, the printing paper 800 is conveyed through the front printer unit 1a so that printing and image reading can be appropriately performed.

The printing unit 200 is input from the control unit 600.
The print image storage unit 240 based on the control signal
Print the stored image data on printing paper.
The printing unit 200 will be described in detail with reference to FIGS.
I will tell. FIG. 3 is a block diagram showing the configuration of the printing unit 200.
It is. FIG. 4A shows the head 220 of the printing unit 200._-1,
220_-24B is a diagram showing the arrangement of
The camera 440 of the reading unit 400_-1, 440_-2Arrangement
FIG. The printing unit 200 includes two printing units 200.
_-1, 200_-2Having. Each printing unit 200 _-i(I = 1,
In 2), a control signal is input from the control unit 600, and printing is performed.
Image data stored in the image storage unit 240
Is read. In addition, in the above-described paper transport unit 110a,
The signals from the encoder 111 are sent to all the printing units 20.
0_-1, 200_-2It is commonly input to.

Each printing unit 200_-i(I = 1,2) is print
Control unit 210_-iAnd head 220 _-iHaving. Print system
The control unit 210 is a control signal input from the control unit 600,
Also, input from the encoder 111 of the paper transport unit 110a.
Based on the applied signal,
The operation timing of the head 220 and the head 220
The ink dropping speed described later is controlled. Head 220
Has a dot density of 240 dpi and a print width Wh of 4
Print control unit 210.
Read from the print image storage unit 240 according to the control from
The projected image data is sequentially recorded. This embodiment
In the two heads 220_-1, 220_-2But Figure 4
As shown in (A), the print dots of each head are continuous.
8 inches as a whole (4 inches
X 2) printing width Wp can now be printed on printing paper
ing.

Further, the printing method of the head 220 will be described with reference to FIG. FIG. 5 is a diagram illustrating the structure and operating principle of the head 220. Head 220
In, the ink 224 in the ink bottle 221 is dropped from the nozzle 222 corresponding to each dot at a cycle of 100 kHz, that is, at a rate of 100,000 drops per second. For each of the inks 224, when the position of the printing paper 800 conveyed under the nozzle 222 is a position where black should be printed, the ink 224 is dropped on the printing paper 800 as it is. , The position of the printing paper 800 is blackened. If the position is a blank position that should not be printed, an electric field is applied by an electric field applying unit (not shown) to draw the ink 224 toward the catcher 223. As a result, the ink 224 is collected in the catcher 223 and is not dropped on the printing paper 800.

By this method, the head 220 is
As shown in FIG. 6, dots having a dot pitch of about 0.1 mm and a dot size of about 0.1 mm in diameter are appropriately printed to print a desired image. It should be noted that in the head 220, it is possible to drop a plurality of inks 224 at the same position, and the printer device 1 thereby expresses pseudo gradation. Further, in the present embodiment, a 240 dpi / 4 inch inkjet head manufactured by Cytex Digital Printing Co. is used as the inkjet head.

The print image storage unit 240 includes the print unit 20.
0 is a memory for storing image data printed on the printing paper 800. Image data transferred from an external host computer via the interface unit 250 is stored in the print image storage unit 240 in a bitmap format. In addition, the print image storage unit 2
The image data stored in 40 is the inspection unit 500.
And an arbitrary location is accessed by the non-print area extraction unit 260. The print image storage unit 240 has a capacity capable of accommodating image data for a plurality of sheets, and is configured by a dual port RAM capable of simultaneous read / write.

The interface section 250 is an interface for transferring image data transferred from a host computer (not shown) to the print image storage section 240, and is a dedicated serial interface in the present embodiment. The print image data is transferred at high speed by the interface unit 250 according to the print speed.

The non-print area extracting section 260 extracts the non-print area on the printing paper 800 based on the image data stored in the print image storage section 240. In the present embodiment, the non-print area is an area in which the print image storage unit 240 does not store image data in the bitmap format in the entire area of the print sheet 800.
In the print image storage unit 240, image data of a substantially effective area for each page of the print paper 800 is stored as, for example, one bitmap data, or
It is stored as a plurality of bitmap data divided into arbitrary areas. In other words, there is an area on the printing paper 800 that is not covered by these bitmap data stored in the print image storage unit 240. For example, it is a peripheral area for each page or a gap area between the divided areas. Further, if the recording medium is continuous paper, there will be a somewhat large non-printing area between each page. The non-print area extraction unit 260 extracts this non-print area.

The image reading unit 400 reads the image on the printing paper printed by the printing unit 200 in order to check the print content and print quality, and the inspection image storage unit 460 as bitmap image data.
Output to The image reading unit 400 is shown in FIG.
This will be described with reference to FIGS. FIG. 7 is a block diagram showing the configuration of the image reading unit 400. The image reading unit 400 includes two image reading units 40.
It consists of 0 _-1 , 400 _-2 . A control signal is input from the control unit 600 to each image reading unit 400 _-i (i = 1, 2). The read image data is output from each image reading unit 400 _-i to the inspection image storage unit 460.

Each image reading unit 400 _-i (i = 1,
2) is a cue mark detection sensor 410 _-i , an encoder section 420 _-i , a light irradiation section 430 _-i , a CCD camera 440 _-i.
And a control unit 450 _-i . The cue mark detection sensor 410 is provided in the vicinity of the CCD camera 440 of each image reading unit 400, and detects the cue mark recorded at each delimiter of the printed matter of the printing paper 800 that is continuously conveyed. When the cue mark is detected, a signal to that effect is output to the control unit 450.

The encoder section 420 is also provided in the vicinity of the CCD camera 440 of the image reading section 400, and detects the conveyance speed of the printing paper 800 detected by the cue mark detection sensor 410. Encoder unit 42
The configuration of 0 will be described with reference to FIG. The encoder section 420 has an encoder 421, a counter 422, and a speed calculation section 423. The encoder 421 rotates integrally with, for example, the printing paper transport roller of the paper transport unit 110a and outputs a predetermined pulse corresponding to the rotation angle. The pulse is counted by the counter 422, and based on the count value within a predetermined time in the speed calculation unit 423,
The transport speed of the printing paper 800 is calculated.

The light irradiating section 430 is a means for giving an appropriate amount of light to an area on the printing paper for capturing an image with a CCD camera 440 described later. In the present embodiment,
The light of the halogen lamp provided in the housing is guided by the fiber cable to irradiate the imaging range of the CCD camera 440. When the CCD camera 440 captures an image, the amount of light required increases as the conveyance speed of the printing paper 800 increases. That is, the transport speed of the printing paper 800 and the required light amount are in a substantially proportional relationship. Therefore, the amount of light emitted by the light emitting unit 430 is equal to the encoder 42.
The control is performed on the basis of the transport speed of the printing paper detected in 1.

The CCD camera 440 reads the printed image and outputs it to the inspection image storage unit 460.
The configuration of the CCD camera 440 will be described with reference to FIGS. 9 and 10. FIG. 9 shows a CCD camera 440.
FIG. 10 is a block diagram showing the configuration of the inspection image storage unit 460, and FIG. 10 is a diagram further explaining the operation of the line sensor 441. The CCD camera 440 includes a line sensor 441, an output amplifier 442, an A / D converter 443,
It has a shift register 444, a line memory 445, and a bus switcher 446.

The line sensor 441 has a resolution of 16 dots / mm, has 2048 elements in the horizontal direction and 96 elements in the vertical direction.
TDI-CC with number of TDI (time delay integration) stages
D (charge coupled device) sensor. Therefore, the reading width Wc by one line sensor 441 is 128 mm. In the present embodiment, the two line sensors 441 _-1 , 441 _-2 are arranged so that their reading ranges partially overlap each other, as shown in FIG.
As a whole, the entire range of the print width Wp of the head 220 can be read. A 15 MHz clock is applied to the TDI-CCD sensor 441. Therefore, one line scan time is about 17 μs.

FIG. 1 shows the TDI-CCD sensor 441.
This will be described with reference to 0. In the TDI-CCD sensor 441, the optical image detected by the element (ROW1) in the first column is imaged on the front surface of the array, and the charges generated by photons are accumulated during the accumulation time corresponding to the scanning of one line.
Collected in the potential well. Then, in the vertical direction (T
The clock in the DI stage) vertically shifts the charge to the next column (ROW2). In the next row, if the same image as before is imaged, the charge generated in ROW2 will be added to the charge from the previous row, and the sensitivity or exposure time will be doubled. Become.

Therefore, if the vertical clock and the TDI transfer direction are synchronized with the motion of the image, TD
It will be integrated by the number of I stages. TD of this embodiment
The I-CCD sensor 441 has 96 TDI stages.
Since it is a step, the detected image is integrated 96 times.
Finally, the integrated data is serially output from the horizontal shift register of the TDI-CCD sensor 441. Also, the TDI-CCD sensor 441 is 2048
It has a horizontal resolution of bits and they are output from 8 taps. Therefore, from one tap, 256
Bit data is output.

The data output from each tap of the TDI-CCD sensor 441 are output amplifiers 442 _{-1 to} 442 _-8.
Are sequentially amplified by A / D converters 443 _{-1 to} 443 _-8
The data is D-converted and input to the shift registers 444 _{-1 to} 444 _-8 . Further, 256-bit data is stored in the line memories 445 _{-1 to} 445 _-8 , and the eight line memories 445 _{-1 to} 445 _-8 are sequentially selected by the bus switcher 446, and the page for each line data is paged. Memory 46
It is input to 0 _-1 .

The control unit 450 controls the image reading unit 40.
0 is controlled. In the control unit 450, the control signal from the control unit 600 and the cue mark detection sensor 41.
Cue mark detection information by 0, encoder unit 420
The control of the light amount of the light irradiation unit 430, the control of reading an image in the CCD camera 440, and the like are performed on the basis of the information of the printing paper conveyance speed by the. In the image reading unit 400, regardless of the size and area of the effective bitmap image printed by the printing unit 200, the printing paper 8
The image of the entire area of 00 is read.

The inspection image storage section 460 is a storage means for storing the image data read by the image reading section 400. In the present embodiment, the page memory 460 is the two page memories 4 corresponding to the two CCD cameras 440 ₋₁ and 440 ₋₂ as shown in FIG.
It is composed of 60 _-1 , 460 _-2 .

The monitor 470 has two CCD cameras 44.
It is a display device for displaying the image data read by 0 _-1 , 440 _{-2 as} it is, and two CCD cameras 440.
_-1 , 440 _-2 corresponding to two monitors 470 _-1 , 470
_-2 . The monitor 470 is usually used by an operator to visually grasp a rough situation, and is used to confirm a print result when an abnormality occurs.

The inspection unit 500 includes an inspection image storage unit 46.
Based on the inspection image data read from the printed matter stored in 0, it is determined whether the printing state is appropriate, and the determination result is output to the control unit 600. The inspection unit 500 sequentially performs three inspections, that is, an inspection of a non-printed area, an inspection based on format information, and an inspection based on matching with original image data, and determines whether or not the printing state is appropriate. The configuration and operation of the inspection unit 500 will be described with reference to FIG. The inspection unit 500 includes a first address counter 501, a second address counter 502,
It has a first compressor 503, a second compressor 504, a matching circuit 505, an error number counter 506, a format information storage unit 507 and a CPU 508.

The first address counter 501 is a counter that controls the address of the print image data stored in the print image storage unit 240 that is read out to the inspection unit 500. In addition, the second address counter 50
2 is an inspection image storage unit 46 to be read out to the inspection unit 500.
It is a counter that controls the address of the inspection image data stored in 0. The image data of the addresses designated by these address counters 501 and 502 is read from the print image storage unit 240 and the inspection image storage unit 460 and input to the inspection unit 500. Note that these address counters 501, 50
2 is controlled by signals such as initial value setting and count up / down input from the CPU 508.

The first compressor 503 and the second compressor 5
Reference numeral 04 compresses the print image data read from the print image storage unit 240 and the inspection image data read from the inspection image storage unit 460 when collating the image data with compressed image data. To do. This compression can be, for example, 2x2 or 3x
The image is divided into 3 pixels, and when the total pixel value of each element is equal to or more than a predetermined value, the corresponding pixel is set to 1, and the original image is compressed to 1/4 or 1/9. Further, when performing collation using the original image data without compression, the first compressor 503 and the second compressor 504 output the input image data as they are. The first compressor 503 and the second compressor 5
04 is enabled and the matching is performed with a compressed image, or the setting of the mode to perform the matching with the image of the original magnification, and the setting of the magnification when performing the matching with the compressed image are controlled externally. It is input by a control signal (not shown) via the unit 600.

The matching circuit 505 includes the first compressor 5
Pixels corresponding to the print image data input from 03 and the inspection image data input from the second compressor 504 are sequentially compared and collated, and the result is output to the error number counter 506. In this matching, the difference between the pixel values of the corresponding pixels is obtained, and if the difference is less than a predetermined value, it is determined that both pixels match, and if the difference is more than the predetermined value, it is determined that the pixels are different. . Error counter 506
Accumulates the number of pixels determined as different pixels in the matching result for each pixel performed by the matching circuit 505, and outputs the accumulated result to the CPU 508 as the number of error pixels.

The format information storage unit 507 stores common format information of print image data input via the control unit 600. This common format information is, for example, data such as a print area of address information, a table position, a mark position, a character position, and other ruled line positions. The information stored in the format information storage unit 507 is read by the CPU 508,
It is used to check the read image data stored in the inspection image storage unit 460.

The CPU 508 controls each unit of the inspection unit 500 to perform the above-described inspection of the non-printing area, the inspection based on the format information, and the inspection by matching with the original image data. The CPU 508 first controls the second address counter 502 based on the non-printing area information extracted and input by the non-printing area extracting unit 260, and the inspection image data stored in the inspection image storage unit 460 is concerned. The non-print area is sequentially accessed in the sub-scanning direction. Then, it is inspected whether or not there is a continuous black pixel of a predetermined length or longer in the non-printing area. If there is such a series of black pixels as a result of the inspection,
It is determined that a black band stripe is generated, and the inspection result indicating that the print result is defective is output to the control unit 600.

The CPU 508 also inspects the image data stored in the inspection image storage unit 460 based on the format information stored in the format information storage unit 507 by a structural analysis method. The check of the inspection image data by the structure analysis method means that the structural features of the print image data are extracted based on the format information of the print image data stored in the format information storage unit 507, and the inspection image data is extracted. Is a process of checking whether or not the print image data is properly printed by checking whether or not it has the same characteristics.

For example, the format information storage unit 507
The information on the position of the blank area having a certain area in the print image data is acquired from the information stored in the check image data, and the corresponding location of the inspection image data stored in the inspection image storage unit 460 is similarly changed to the blank area. Check whether or not. If the area is properly a blank area, move to the next check, and if black pixels above noise are detected in that area, end the check and control the inspection result indicating that the print result is defective. It is output to the unit 600. Further, for example, the ruled line information stored in the format information storage unit 507 is acquired, and the inspection image storage unit 4 is acquired.
The vertical or horizontal black pixel histogram of the corresponding area is obtained from the inspection image data stored in 60, and it is checked whether or not there is a ruled line at that position.

Further, when a region where characters are printed is scanned in the direction of the character string, black pixels and white pixels frequently change, so that it is possible to detect that characters are printed there. By such a method, it is checked whether the character is printed in the area where the character should be printed. In addition, check whether the table is in the proper position on the table and whether the mark is appropriate. During the inspection by the structural analysis method, the inspection result indicating that the print result is defective is output to the control unit 600 immediately when the contradiction is detected, and the subsequent processing is ended.

Further, the CPU 508 controls the first address counter 501, the second address counter 502, and the first compressor 503 to the error number counter 506 to be stored in the print image storage section 240. Matching processing between the original image data and the inspection image data stored in the inspection image storage unit 460 is performed.
Then, the error pixel number input from the error number counter 506 is compared with the threshold value THL, and the error pixel number is determined by the threshold value T.
If it becomes larger than HL, defective printing is judged, and if matching is completed without exceeding the threshold value THL, normal printing is judged.

Before performing these inspections, the CPU 5
In 08, the print image data and the inspection image data are aligned. This alignment is a process of detecting the corresponding position of the image data on each image memory of the print image storage unit 240 and the inspection image storage unit 460. For example, the pixel on the upper side where the cue mark of both image data is detected. Take measures based on
The center of gravity point of both black pixels is detected, and the corresponding pixel is determined based on that point. By the operation of the CPU 508, the inspection unit 500 inspects the print image data stored in the inspection image storage unit 460.

The control section 600 controls each section constituting the printer apparatus 1 to perform a desired operation. To the control unit 600, via the Ethernet I / F in the control unit 600,
Printing conditions and control conditions are input from the host computer of the upper level. Based on the input data, the control unit 600 sets operating conditions of the paper transport unit 110a, the printing unit 200, the image reading unit 400, and the like, transports the print paper, prints on the print paper, and prints the printed image. Make sure the reads are synced properly. Also,
The control unit 600 controls the sheet conveyance unit 110a, the printing unit 200, and the like so as to immediately stop the printing work when the signal indicating the printing failure is input from the inspection unit 500 during the printing work. .

The operation unit 610 is an operation terminal for performing relatively simple operations such as setting work conditions and print parameters on the printer device 1 and notifying the operator of the data notified from the printer device 1. is there. In this embodiment, a general-purpose personal computer is a RS23.
It is used by connecting with a 2C interface. A log file of the inspection result of the printing state and the like are also output to the operation unit 610.

Next, the operation of the printer device 1 will be described with reference to FIG.
2 will be described. FIG. 12 is a diagram showing a state where image data is printed on the printing paper 800, which is continuous paper, by the printer device 1. The print target shown in FIG. 12 is
For example, an invoice for telephone charges, a printing paper 800
Billing address 801, billing of various information 802, the item 803 _-1 ～803 _-3 according contents printed on. Also,
A cue mark 804 is printed on the upper right of the first page of each bill. With this cue mark, 1 from continuous paper
You can know the delimiter position of each invoice. Note that, although FIG. 12 is a diagram showing a printing state on one surface of the printing paper 800, similar printing is performed on the back surface.

Hereinafter, such a bill will be sent to the printer device 1.
The operation of the printer device 1 will be described for the case of printing with. First, with respect to the printer device 1, the operation unit 610,
Alternatively, print contents, print conditions, etc. are input via a host computer of a higher rank. As a result, the control unit (not shown) sets operating conditions for the front printer unit 1a, the back printer unit 1b, the paper transport unit 110, and the like. When the condition setting is completed, the actual printing work can be started. As the print paper 800 is sequentially supplied from the roll paper supply unit 110 _-1 to the front printer unit 1a, print bitmap image data is sequentially input to the front printer unit 1a via the interface unit 250, and the print image is printed. It is stored in the storage unit 240. Then, the image data stored in the print image storage unit 240 is transferred to the print unit 2
00 is read and printing is performed on the supplied printing paper 800. As a result, the billing address 80 as shown in FIG.
1, various billing information 802 and bill details 803
Invoices having items of _{-1 to} 803 _-3 are sequentially printed.

Further, at this time, the non-print area extracting section 260
Reads the image data stored in the print image storage unit 240 and detects a non-printing area that is not covered by the bitmap data in the area on the printing paper 800. As a result, in the example shown in FIG. 12, for example, the non-printing including the margin 808 _-1 between the first and second pages and the margin 808 _-2 between the second and third pages. Area 808 is extracted.

The image printed on the printing paper 800 is read by the image reading section 400 and stored in the inspection image storage section 460. Inspection image storage unit 46
The image data stored in 0 is used for the inspection of the print state in the inspection unit 500, and at the same time, is sequentially monitored by the monitor 47.
Output to 0.

In the inspection section 500, first, printing paper is used.
Non-printing detected by the non-printing area extraction unit 260 on 800
There is a black belt stripe in the area corresponding to the area 808.
Check whether or not Specifically, the inspection image storage unit
Non-printing of inspection image data stored in 460
The area corresponding to the area is sequentially arranged in the sub-scanning direction of the printing paper 800.
Scan. Then, in the area where black pixels are predetermined
A black belt streaker is present when it continues for more than a certain threshold.
It is present, and it is determined that the print head is above. What
Note that this threshold takes into consideration the amount of noise that can occur.
And decide. And it was decided that there was a black belt striker.
If it is set, it immediately indicates that the printing status is not appropriate.
Signal is output to the control unit 600, and the control unit 600 immediately
Stop the printing process. In the example shown in FIG. 12, 2
Black striped streakers 810 occur in the middle of the page
I have. In this case, the second and third pages
White space 808 _-2This black belt striker 8 when scanning
10 is detected and a signal indicating that the printing status is not appropriate is controlled
The output is output to the unit 600, and the printing process is ended.

If the black band stripes are not present in the non-printing area, the inspection image data stored in the inspection image storage unit 460 is stored in the format information storage unit 507 as the next stage inspection. Whether or not it has structural features that are compatible with the format information, that is, as described above, a predetermined blank area, a character string,
Inspect whether ruled lines are properly present. Also during this inspection, if it is determined that the characteristics of the inspection image data are not appropriate, a signal indicating that the printing state is not appropriate is immediately output to the control unit 600, and the control unit 600 immediately stops the printing process.

Then, as the final inspection, the print image data stored in the print image storage unit 240,
Matching with the inspection image data stored in the inspection image storage unit 460 is performed. Both images are sequentially compared with each other by the compressed image or the original image, and when there are a predetermined number or more of different pixels, the two images do not match,
That is, it is determined that the printing state is not appropriate for some reason, and a signal to that effect is input to the control unit 600. In the control unit 600, as in the case of other inspections up to now, the sheet conveyance unit 110 and the printing unit 200 are instructed to stop the processing, and the printing operation is immediately stopped. When all of these three stages of inspection are cleared, it is determined that the printing has been properly performed, and the printing is continued.

[0058] passes through the table printer unit 1a, the printing paper 800 the desired image data is printed on the surface, both sides are reversed by the sheet reversing unit 110 _-7, back printer unit 1
b. The back printer unit 1b is the front printer unit 1
By the same operation as a, desired image data is printed on the back surface of the printing paper 800 and an inspection is performed. As a result, when it is determined that the printing is not properly performed, the printing operation is immediately stopped. Then, the printing paper 800 printed on both sides has been performed is taken up successively in the roll paper take-up unit 110 _-6 5.

As described above, in the printer device 1 of the present embodiment, the blank area not covered by the print image data is set as the non-printing area, and the black stripe striker is detected by scanning this area in the sub-scanning direction. are doing. Therefore, it is possible to first detect the black band streaker by a simple process to detect an abnormality in the print head, and to quickly detect defective printing. In particular, such a black band streaker often occurs in an inkjet type printer device such as the printer device 1, and thus is more effective in such a printing type printer device. Further, since the non-printing area is extracted by the non-printing area extracting unit based on the input image data, the control for the printer device 1 does not become complicated and the scanning does not become complicated. It can be used with the same operability as a printer device.

Further, in the printer device 1, after the inspection based on the non-print area, the structural characteristics thereof are further extracted based on the format information of the print image data to inspect the print state. As a result, for example, a streaker or a blank area that occurs in the print area is effectively detected, and the print state can be effectively inspected. Then, in the printer device 1, after the inspection based on the structural characteristics, template matching between the print image data and the inspection image data is further performed to inspect the print state. As a result, small differences such as differences in print contents are accumulated and extracted, and the print state can be more effectively and accurately inspected. In this way, since the printer device 1 performs the three-step inspection on each printed matter,
It is possible to inspect the printing state from various aspects, appropriately detect and eliminate defective printed matter, and output accurate and high-quality printed matter.

Further, in the printer device 1, when the defective printing is found, the operation of the printer device 1 is immediately stopped, so that the generation of the defective printed material can be suppressed to the minimum, and the time and printing resources can be reduced. It is possible to minimize waste such as.

The present invention is not limited to this embodiment, but various modifications can be made. For example, in the inspection unit 500 according to the present embodiment, the first inspection using the information of the non-print area and the second inspection using the format information.
And the third inspection by matching are performed to check the printing state. But,
Such an inspection is not essential, and an arbitrary method may be used for the inspection other than the first inspection using the information of the non-printed area according to the present invention. The second inspection and the third inspection may be omitted or a new inspection may be performed based on the experience of the reliability of the print head and the resulting defects. Further, as the format information of interest and the matching method, any information and method may be used.

Also, in the first inspection method based on the information of the non-printing area performed by the inspection unit 500, in the present embodiment, the image data is scanned in the sub-scanning direction of the printing paper 800 to obtain black. The pixels are continuously arranged. This method is very effective for detecting black band streakers that often occur in inkjet type heads,
This is also not limited to this method. For example, the same streaker detection may be performed in the main scanning direction, or scanning in an arbitrary direction may be performed to extract blocks of black pixels that are continuous in a predetermined number or more. By doing so, it is possible to detect, for example, a drop of ink that has dropped in spots, and it is possible to detect more than a wider range of print heads.

The printing medium to be printed by the printer device 1 is not limited to the continuous paper as shown in this embodiment, but may be cut paper, or a printing medium made of a material other than paper. May be. Even when the print medium is a cut sheet as shown in FIG. 13, the non-print area extraction unit 260 extracts the same non-print area as in the case of continuous paper. For example, as shown in FIG.
A blank area 808b other than the print image data 801b and 802b in b is detected as a non-print area.

Further, in the present embodiment, the non-printing area extracting section 260 detects an area on the printing paper 800 which is not covered by the bitmap data stored in the printing image storing section 240, and the non-printing area is detected. The area was. However, the content of the bit map data may be further analyzed, a blank area may be extracted from the content, and the blank area may also be extracted as a non-print area.

A specific description will be given with reference to FIG. In FIG. 14, the print image storage unit 240 has an area 8
Bit map data for each of 01 to 803 is stored, and in the above-described embodiment, the area other than these areas is extracted as the non-print area 808. But,
Further analyzing the contents of each bitmap data,
For example, area 803 _-2 is made up of a series of character blocks 809 _-2 and 809 _-3 , with a blank area 8 between them.
The presence of 08 _-3 can be extracted. Therefore,
The non-printing area extraction unit 260 may analyze the contents of the bitmap data to extract these blank areas, and set them as the non-printing areas that can be referred to by the inspection unit 500. With such a configuration, it is possible to detect the black band stripes with higher accuracy, and it is possible to quickly find the black band stripes that have occurred in the area covered by the image data.

Further, in the printer device 1 of the present embodiment, the printable width is 8 inches by using two print heads 220 and two CCD cameras 440 each. However, the print width may be set to 16 inches by using, for example, four print heads 220 and CCD cameras 440.
The number of cameras 440 and the print width may be arbitrary according to the print target. Further, in the printer device 1 of the present embodiment, the front printer unit 1a and the back printer unit 1
Double-sided printing is performed in which printing is performed on both the front and back sides of the printing paper 800 using b. However, it is clear that the present invention can be applied to simplex printing. In that case, the paper reversing unit 110 _-7 and the back printer unit 1b are unnecessary, and the configuration becomes simpler.

Further, in the present embodiment, the printer device 1 is stopped immediately when the defective printing is detected, but the procedure after the defective printing is detected may be arbitrarily determined. For example, the printer device 1 may be stopped when defective printing occurs continuously for some time. A black belt streaker or the like that is temporarily generated by the inkjet head may recover naturally after a while. If recovery from such a printing defect can be expected, and if the process until restarting the printer device once is complicated and takes time, for example, even if a printing defect is detected, operation is not stopped and the device is not stopped. Printing may be performed more efficiently if continued. In such a case, the printer device may not be immediately stopped but may be continuously operated as much as possible. At that time, the conditions for stopping the printer device 1 and the like may be arbitrarily determined.

If such a printer device is not stopped immediately, the defective printed matter is identified, or
In order to properly eliminate the defective printed matter, it is necessary to easily identify the printed matter determined to be defective in printing later. For that purpose, for example, it is desirable to display the identification code, bill number, etc. on the monitor 470 or the like.

Further, it is also possible to adopt a structure in which some kind of marking is made on the printed matter which is judged to be defective in printing.
FIG. 15 shows a schematic external view of the printer device 1b having such a configuration. The printer device 1b shown in FIG. 15 is a printer device having a print width of 16 inches using four print heads 220 and four CCD cameras 440 and performing only one-sided printing. In this printer device 1b, a defective print marking unit having a filling print head 631 and a defective display mark print head 632 is provided at the subsequent stage of the unit of the inspection unit 500. The defective printing marking unit operates under the control of the control unit 600 based on the inspection result of the inspection unit 500, and prints a mark as shown in FIG. 16 on the printed matter determined to be defective printing.

That is, the defective display mark print head 63
2 is used to print an error code 822 consisting of a predetermined character string that makes it possible to understand the cause of the defective printing, and the print head 631 for filling is used to print the address 801 of the printed matter.
The filling pattern 821 for invalidating is printed. The error code 822 is a bar code,
OCR characters or arbitrary figures may be used. In addition, for the explanation that clearly states that the printed matter is not effective in advance, by marking that the explanation is valid, it is possible to exclude the printed matter as a defective printed matter. Good. As described above, any method may be used as the treatment after detecting the print defect.

Further, the printer device 1 of the present embodiment is
The non-print area extraction unit 260 is configured to extract the non-print area by referring to the image data stored in the print image storage unit 240. However, the data indicating the non-print area is external, that is, Alternatively, it may be input together with print image data from a host computer or the like. With such a configuration, a storage unit for storing the input data indicating the non-printing area is required, but the non-printing area extracting unit 260 is not required,
The device configuration is simplified. It is obvious that the printer device 1 having such a configuration is also within the scope of the present invention which examines the existence of the black band stripes in the non-printing area.

Further, in the present embodiment, the inspection unit 5
The inspection result of 00 is once input to the control unit 600, and based on a control signal from the control unit 600, for example, processing such as stopping the printing operation is performed in the paper transport unit 110 or the printing unit 200. However, when processing is concentrated on the control unit 600, there may be a case in which a signal is transmitted via the control unit 600, which causes a time lag and the device cannot be stopped immediately. In such a case, the inspection unit 500 to the sheet conveying unit 110 or the head 220
A signal for stopping the process may be directly sent to the related components such as when a print defect is detected.

Further, the present invention is not limited to the printer device which performs printing in two colors of black and white like the printer device of the present embodiment, but performs multi-value printing, multi-color printing, full-color printing or the like. It can also be applied to a printer device. Further, it may be a printer device that performs front and back printing. Other signal processing, signal transmission paths, etc. may be arbitrarily modified within the scope of the present invention.

[0075]

According to the printer device of the present invention, a printing defect can be detected easily and accurately at high speed. Therefore, when a printing defect occurs, it is possible to immediately take measures such as stopping the printer device. . As a result, it is possible to prevent a decrease in efficiency such as generation of a large number of defective printed materials, efficiently perform normal printing, and provide a highly reliable printer device capable of performing accurate and high-quality printing at high speed. .

[Brief description of drawings]

FIG. 1 is a schematic external view of a printer apparatus main body according to an embodiment of the present invention, (A) is a side view of the main body, and (B) is a top view of the main body.

FIG. 2 is a block diagram showing a configuration of a front printer unit of the printer device shown in FIG.

FIG. 3 is a block diagram showing a configuration of a printing unit of the front printer unit shown in FIG.

4A and 4B are diagrams showing an arrangement state of a print head and a CCD camera of the front printer section shown in FIG. 2, FIG. 4A showing an arrangement state of the print head, and FIG. 4B showing an arrangement state of the CCD camera. FIG.

5A and 5B are diagrams illustrating a structure and an operating principle of the head of the printing unit illustrated in FIG.

6 is a diagram showing a printing state by the head shown in FIG.

7 is a diagram showing a configuration of an image reading unit of the front printer unit shown in FIG.

8 is a diagram showing a configuration of an encoder unit of the image reading unit shown in FIG.

9 is a diagram showing a configuration of a CCD camera of the image reading unit shown in FIG.

10 is a diagram illustrating the configuration and operation of a TDI-CCD sensor used as a line sensor of the CCD camera shown in FIG.

11 is a block diagram showing a configuration of an inspection unit of the front printer unit shown in FIG.

FIG. 12 is a diagram showing image data printed on printing paper which is continuous paper by the printer device shown in FIG.

13 is a diagram showing image data printed on a print sheet which is a cut sheet by the printer device shown in FIG.

FIG. 14 is a diagram showing a print image for illustrating a modified example of the operation of the non-print area extraction unit of the front printer unit shown in FIG. 2.

15A and 15B are external views for explaining a printer device according to a modified example of the present embodiment, in which FIG. 15A is a side view and FIG. 15B is a top view.

FIG. 16 is a diagram for explaining marking on a printed matter, which is a modified example of the treatment when a print defect is detected.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printer device, 110 ... Paper conveyance part, 200 ... Printing part, 240 ... Print image storage part, 250 ... Interface part, 260 ... Non-print area extraction part, 400 ... Image reading part, 460 ... Inspection image storage part, 470 …
Monitor, 500 ... Inspection section, 600 ... Control section, 610 ... Operation section, 800 ... Printing paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taizo Otani 3-18-5 Takaidohigashi, Suginami-ku, Tokyo (72) Inventor Tsutomu Yoneda 1-2-4-102 Shirayama, Aso-ku, Kawasaki-shi, Kanagawa

Claims (9)

[Claims] 1. A printer device for high-speed printing of sequentially input data, comprising: printing means for printing input image data on a print medium; and an image sensor for reading an image on the printed print medium. Means and an image data of the read image data in an area corresponding to a non-printing area of the printing medium, the print state is inspected, and whether the printing is appropriately performed or not is determined. A printer device having an inspection means for judging. 2. The printer device according to claim 1, wherein the printing means has an inkjet head, and performs the printing by an inkjet method. 3. A non-print area extracting means for extracting a blank area from the print medium as the non-print area based on the input image data.
Or the printer device according to 2. 4. The printer according to claim 3, wherein the non-print area extracting means further detects a blank area in the input image data and extracts the blank area and the blank area as the non-print area. apparatus. 5. The inspecting means inspects whether or not black pixels are continuous in a sub-scanning direction by a predetermined value or more in the read image data in an area corresponding to the non-print area, 5. The printer device according to claim 1, wherein the printing state is determined to be inappropriate when a series of black pixels exists. 6. The inspection means further extracts structural features from the read image data, and refers to the format information of the input image data to determine whether or not the extracted features are appropriate. 6. The printer device according to claim 1, wherein the printer device is inspected to determine whether the printing is properly performed. 7. The inspecting means further performs template matching between the input image data and the read image data, and detects a difference between them.
7. The printer device according to claim 1, wherein it is determined whether or not the printing has been appropriately performed based on the amount of the difference. 8. The printer device according to claim 1, wherein the printing unit stops the printing when the inspection unit determines that the printing state is inappropriate. 9. The printing apparatus further comprises a second printing unit that further prints a print that substantially invalidates the printing on the printing medium when the printing unit determines that the printing state is inappropriate. Item 9. A printer device according to any one of items 1 to 8.