JP2994257B2 - Printer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a method of recording predetermined information on a medium such as paper so as to be visually recognizable, a method of recording the same contents in a printing machine at high speed and in a large amount by using a printing plate, and a method of using a computer. There is known a method of printing arbitrary data on a relatively small number of media at a low speed by a printer or the like used as a terminal device. In addition, there is also a demand for printing documents that are large in volume and have to be printed with different numbers and contents, such as stock certificates, various kinds of vouchers, and a large number of bills for a large number of customers. There is a high-speed printer for this purpose.

[0003] Such a printer apparatus for printing variable data at a high speed includes a conveying means for conveying a print medium at a high speed, a printing means for recording an image at high speed on a sheet conveyed by the conveying means, and a printing means for sequentially inputting. It is composed of control means for appropriately controlling data so that the data is appropriately printed on paper. As the printing means, for example, a method of performing printing by an inkjet method using an inkjet head is applied. As such a high-speed printer device that performs printing by the ink jet method, for example, a device that performs printing at a speed of 15 sheets per second or more for A4 size printing paper at 5 m / s has been put to practical use.

[0004] By the way, in such a printer device of the ink jet system, although high-speed printing is possible, there is a problem that printing defects called streaker such as ink drips and white spots are apt to occur. Since these are inherently difficult to solve because of the problems inherent in the ink jet system, the state of the print head in such a printer apparatus substantially determines the print quality. Therefore, in order to prevent defective printed materials from being output to the outside in such a printer device,
It is necessary to check the print result by some method.

[0005]

However, in such a conventional printer device, an inspection can only be performed by an operator by visual inspection or by using a cue mark or the like to check a printing misalignment. There has been no means for properly and automatically inspecting the print result. Therefore, especially in the high-speed printer device described above, if the operator notices the occurrence of a printing failure late, an enormous amount of defective printed matter is created, a large amount of printing resources are wasted, and time is reduced. In addition, there has been a problem in that a huge loss is caused in terms of cost and the printing cost is increased. Further, in such a printer device, it is difficult to distinguish between a black band streaker and a ruled line because the printed content is different for each printed matter, and the inspection must be performed as fast as printing. Due to problems, it was difficult to provide an appropriate automatic inspection method.

Accordingly, an object of the present invention is to detect printing defects caused by a print head such as a black band streaker in an appropriate and simple manner at a high speed, thereby eliminating defective printed materials and performing accurate and high-quality printing. It is an object of the present invention to provide a highly reliable printer device.

[0007]

In order to solve the above problems, an image printed on a printing medium is read by a sensor, and a non-printing area where an original print image does not exist is scanned to print a black band streaker or the like. Detect defects .

Accordingly printer apparatus of the present invention, sequentially
A printer device for printing input data.
Printing means for printing the input image data on a print medium, and reading the printed image on the print medium
And non-image sensor means, the loaded image data
Of the area corresponding to the non-print area of the printing medium
Effective print pixels in the sub-scanning direction
Inspect whether it is more than a constant and check if the print is valid
When there is a continuation of pixels, the printing state is inappropriate.
By judging, the state of the printing is inspected and the printing
Inspection means for determining whether or not the inspection is properly performed .

Preferably , the inspection means further comprises:
Extract structural features from the loaded image data,
Refer to the format information of the input image data.
Whether the extracted features are appropriate or not, and
It is determined whether the printing has been properly performed .

[0010] good applicable, the test unit further template matching and image data read and inputted image data, to detect the difference between them,
Determine whether or not printing is performed appropriately based on the amount of the difference
Set .

[0011] In particular, in the printer apparatus of the present invention stops the printing if the print state is determined to be inappropriate by the inspection means. Also, specifically,
Printer equipment of the present invention, when the state of the printing is determined to be inappropriate by said inspecting means, a second printing means further prints the printing of substantially disabling the printing on the printing medium Have more .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a printer according to the present invention will be described with reference to FIGS. The printer according to the present embodiment is a large-scale printing system that prints print data input from a host computer at a high speed using a plurality of inkjet heads. This makes it possible to detect defective printing.

FIG. 1 shows a printer 1 according to the present embodiment.
It is a schematic external view of a main body, (A) is a side view, (B) is an upper side.
FIG. As shown in FIG. 1, the printer 1
Printer unit 1a, back printer unit 1b, and paper transport
It has a unit 110. Also, the paper transport unit 110 is provided with a roll
Paper supply unit 110_-1, Table mark included in table printer section 1a
Printing unit paper transport unit 110 _-2And paper transport in front inspection section
Unit 110_-3, Paper reversing unit 110_-7, Back pre
Back printing section paper transport unit 11 contained in printer section 1b
0_-FourAnd paper inspection unit 110_-Five, And
And roll paper take-up unit 110_-6It is composed of

[0014] In the printer apparatus 1 configured as described above, continuous printing paper 800 is fed from the roll paper supply unit 110 _-1, printed on the surface of the sheet 800 in the table the printer unit 1a is performed, the sheet reversing unit 110 _-7 and that paper 8
00 is reversed, the back printer unit 1b prints on the back surface of the paper 800, and prints on both sides of the paper 811
0 _-7 is wound around the roll paper take-up unit 110 _-6. The printer device 1 includes a control unit and an operation unit (not shown) housed in a separate housing separately from a main body whose appearance is shown in FIG. Have.

Hereinafter, the configuration of each part of the printer 1 will be described. First, the paper transport unit 110 is a paper feed mechanism for stably transporting the printing paper 800 as a medium to be printed at a high speed and at a predetermined speed. The printing apparatus 1 according to the present embodiment has a printing paper 80 in which continuous paper is wound in a roll shape.
0 is printed on both sides. Therefore, the paper transport unit 1
10 is a roll paper supply unit 110 _-1 for supplying roll paper,
Print heads 220a- ₁ and 220a- _{2 of the} front printer section 1a
Front printing unit paper transport unit 11 that transports print paper below
0 _-2 , CCD cameras 440a _-1 and 4 of the front printer unit 1a
40a _-2 table check section sheet conveying unit 110 _-3 for conveying the printing paper under the paper reversing unit 110 _-7 to reverse the sides of the printing paper 800, print head 220b of the back printer unit 1b _-1, 220b _-2 under The back printing section paper transport unit _110-4 for transporting the printing paper, and the CC of the back printer section 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 are integrally connected.

Each unit includes 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 transport / stop of the printing paper, Adjust the speed.
Further, as shown in FIG. 1B, an encoder 111 is provided on a paper feed roller near the head of the front printing unit paper transport unit 110 _-2 , and a pulse from the encoder 111 determines the timing of printing. The signal to be generated is used in each unit of the printer device 1. Further, a cue mark is printed on the printing paper 800 supplied from the roll paper supply unit _110-1 by a cue mark printing unit (not shown) immediately after being supplied to the printing unit 200. Thereafter, each of the heads and cameras, which will be described later, detect the cue mark by a cue mark detection sensor provided in the vicinity thereof, and perform positioning in the sub-scanning direction on the printing paper 800. Note that the paper transport unit 110 of the present embodiment has a
The printing paper 800 is conveyed in about s.

Front printer section 1a and back printer section 1b
Prints on the front surface or the back surface of the printing paper 800, respectively. 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 illustrating the configuration of the front printer unit 1a. The front printer unit 1a includes a sheet 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 section 200 receives an input from the control section 600.
Is stored in the print image storage unit 240 based on the control signal
The stored image data is printed 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 illustrating a configuration of the printing unit 200.
It is. FIG. 4A shows the head 220 of the printing unit 200._-1,
220_-2FIG. 4B is a view showing the arrangement of
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 image storage unit 240
Is read. In addition, the above-described paper transport unit 110a
The signal from the encoder 111 is transmitted to all the printing units 20.
0_-1, 200_-2Is input in common.

Each printing unit 200_-i(I = 1,2) means print
Control unit 210_-iAnd head 220 _-iHaving. Printing system
The control unit 210 includes a control signal input from the control unit 600,
And input from the encoder 111 of the paper transport unit 110a.
Based on the input signal,
The operation timing of the head 220 and the
The ink drop speed described later is controlled. Head 220
Means that the dot density is 240 dpi and the print width Wh is 4 inches.
Print control unit 210
Read from the print image storage unit 240 in accordance with the control from
The detected image data is sequentially recorded. This embodiment
In the two heads 220_-1, 220_-2But FIG.
As shown in (A), the print dots of each head are continuous.
8 inches (4 inches)
× 2) printing on printing paper with a printing width Wp.
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 operation principle of the head 220. Head 220
In the above, 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. If the position of the printing paper 800 being conveyed below the nozzles 222 is a position to be printed in black for each of the inks 224, the ink 224 is directly dropped on the printing paper 800. , The position of the printing paper 800 is blackened. If the position is a blank position where printing should not be performed, an electric field is applied by an electric field applying means (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.

According to such a method, the head 220
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, and a desired image is printed. In addition, in the head 220, a plurality of inks 224 can be dropped at the same position, and the printer device 1 expresses a pseudo gradation by this. In the present embodiment, a 240 dpi / 4 inch inkjet head manufactured by Scitex Digital Printing Co., Ltd. is used as the inkjet head.

The print image storage section 240 stores the print section 20
0 is a memory for storing image data to be 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. The print image storage unit 2
The image data stored in the inspection unit 500
An arbitrary location is accessed by the non-print area extracting unit 260. The print image storage unit 240 has a capacity capable of accommodating a plurality of image data, and is configured by a dual-port RAM that can simultaneously 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. In the present embodiment, the interface section 250 is a dedicated serial interface. The print image data is transferred at a high speed by the interface unit 250 according to the printing speed.

The non-print area extracting section 260 extracts a 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-printing area is an area where the bitmap format image data is not stored in the print image storage unit 240 in the entire area of the printing paper 800.
The print image storage unit 240 stores image data of a substantially effective area for each page of the printing paper 800, for example, as 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, a peripheral area for each page, a gap area between the divided areas, and the like. Further, if the recording medium is continuous paper, a non-printing area which is somewhat large exists between pages. The non-print area extracting section 260 extracts the non-print area.

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

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

The encoder section 420 is provided near the CCD camera 440 of the image reading section 400, and detects the transport speed of the printing paper 800 detected by the cue mark detection sensor 410. Encoder section 42
0 will be described with reference to FIG. The encoder unit 420 includes an encoder 421, a counter 422, and a speed calculation unit 423. The encoder 421, for example, rotates integrally with the print 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 the speed calculation unit 423 calculates the pulse based on the counted value within a predetermined time.
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 a printing sheet for capturing an image by a CCD camera 440 described later. In the present embodiment,
Light from a halogen lamp provided in the housing is guided by a fiber cable and is applied to an imaging range of the CCD camera 440. When capturing an image with the CCD camera 440, the required light amount increases as the transport speed of the printing paper 800 increases. That is, the transport speed of the printing paper 800 and the required light amount are substantially proportional. Therefore, the amount of light irradiated by the light irradiating section 430 is
The control is performed based on 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. FIG. 9 shows a CCD camera 440.
10 is a block diagram illustrating a configuration of the inspection image storage unit 460. FIG. 10 is a diagram further illustrating an operation of the line sensor 441. The CCD camera 440 includes a line sensor 441, an output amplifier 442, an A / D converter 443,
A shift register 444, a line memory 445, and a bus switcher 446 are provided.

The line sensor 441 has a resolution of 16 dots / mm, 2048 elements in the horizontal direction, and 96 pixels in the vertical direction.
TDI-CC with TDI (time delay integration) number of stages
This is a D (charge coupled device) sensor. Therefore, the reading width Wc of one line sensor 441 is 128 mm. In the present embodiment, the two line sensors 441 _-1 and 441 _-2 are arranged with their reading ranges partially overlapping 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.
0 will be described. In the TDI-CCD sensor 441, the optical image detected by the element (ROW1) in the first column forms an image on the front surface of the array, and the charge generated by the photons is stored during the accumulation time corresponding to one line scan.
Collected in a potential well. Then, in the vertical direction (T
With the clock in the DI stage direction, the charges are vertically shifted to the next column (ROW2). In the next column, if the same image as before was formed, the charge generated in ROW2 would be added to the charge from the previous column, doubling the sensitivity or exposure time. Become.

Therefore, if the clock in the vertical direction and the TDI transfer direction are synchronized with the movement of the image, TD
It will be integrated by the number of I stages. TD of the present embodiment
In the I-CCD sensor 441, the number of TDI stages is 96
As a step, the detected image is integrated by a factor of 96.
The integrated data is finally output serially from the horizontal shift register of the TDI-CCD sensor 441. The TDI-CCD sensor 441 is 2048
It has a horizontal resolution of bits, which are output from eight taps. Therefore, from one tap, 256
Bit data is output.

The data output from the respective taps of the TDI-CCD sensor 441, an output amplifier 442 _-1 ～442 _-8
Are sequentially amplified by A / D converters 443 _{-1 to} 443 _-8 .
It is D-converted and input to the shift registers 444 _{-1 to} 444 _-8 . Further, 256 bits of data are 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 a page is set for each line of data. Memory 46
It is input to the 0 _-1.

The control unit 450 includes an image reading unit 40
0 is controlled. The control unit 450 includes a control signal from the control unit 600 and the cue mark detection sensor 41.
Information of cue mark detection by 0, encoder section 420
The control of the light amount of the light irradiation unit 430 and the control of image reading by the CCD camera 440 are performed based on the information of the printing paper conveyance speed by the printer. 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 storage means for storing the image data read by the image reading section 400. In the present embodiment, the page memory 460 includes two page memories 4 corresponding to the two CCD cameras 440 _-1 and 440 _-2 as shown in FIG.
60 _-1 and 460 _-2 .

The monitor 470 has two CCD cameras 44
A display device for directly displaying image data read by 0 _-1 and 440 _-2 , and two CCD cameras 440
_-1 , 470 _-2 corresponding to two monitors 470 _-1 , 470 _-2
-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 section 500 includes an inspection image storage section 46
Based on the inspection image data read from the printed matter stored in “0”, it is determined whether or not the printing state is appropriate, and the determination result is output to the control unit 600. The inspection unit 500 sequentially performs three types of inspections: an inspection of a non-print area, an inspection based on format information, and an inspection based on matching with original image data, and determines whether 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 counter 506, a format information storage unit 507, and a CPU 508.

The first address counter 501 is a counter for controlling the address of the print image data stored in the print image storage unit 240 to be read out to the inspection unit 500. Also, the second address counter 50
2 is an inspection image storage unit 46 to be read out to the inspection unit 500
This is a counter for controlling the address of the inspection image data stored in 0. The image data at the addresses designated by the address counters 501 and 502 are read out from the print image storage unit 240 and the inspection image storage unit 460 and input to the inspection unit 500. These address counters 501, 50
2 is controlled by signals such as initial value setting and count up / down input from the CPU 508.

First compressor 503 and second compressor 5
Reference numeral 04 denotes a case where the collation of the image data is performed using the compressed image data, 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 are each compressed. I do. This compression is, for example, 2 × 2 or 3 ×
The image is divided into three pixels, and when the total pixel value of each element is equal to or more than a predetermined value, a process of setting the corresponding pixel to 1 is performed, and the original image is compressed to 1/4 or 1/9. When collation is performed using original image data without performing compression, the first compressor 503 and the second compressor 504 each output the input image data as it is. Note that the first compressor 503 and the second compressor 5
The setting of the mode of whether the comparison is performed with the compressed image or the comparison with the image of the original magnification and the setting of the magnification when the comparison is performed with the compressed image, etc. is externally controlled. A control signal (not shown) is input through the unit 600.

The matching circuit 505 includes the first compressor 5
Corresponding pixels of the print image data input from the input unit 03 and the inspection image data input from the second compressor 504 are sequentially compared and collated, and the result is output to an error counter 506. In this comparison, the difference between the pixel values of the corresponding pixels is determined. If the difference is less than a predetermined value, the pixels are determined to be the same, and if the difference is equal to or greater than the predetermined value, the pixels are determined to be different. . Error counter 506
Accumulates the number of pixels determined as different pixels in the result of the matching performed for each pixel 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. The 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. Information stored in the format information storage unit 507 is read by the CPU 508,
It is used for checking 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. First, the CPU 508 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 controls the second address counter 502 of the inspection image data stored in the inspection image storing unit 460. The non-print area is sequentially accessed in the sub-scanning direction. Then, it is checked whether or not there is a continuation of black pixels longer than a predetermined length in the non-printing area. If such a sequence of black pixels exists as a result of the inspection,
It is determined that a black band streaker has occurred, and an inspection result indicating that the printing result is defective is output to the control unit 600.

The CPU 508 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 structural analysis method is to extract the structural features of the print image data based on the format information of the print image data stored in the format information storage unit 507, Is a process for checking whether or not the print image data is appropriately printed by checking whether or not the print image data has the same characteristics.

For example, format information storage unit 507
The information of the position of the blank area having a certain area in the print image data is obtained from the information stored in the print image data, and the corresponding location of the inspection image data stored in the inspection image storage unit 460 is similarly stored in the blank area. Check if it is. If the area is properly a blank area, proceed to the next check, and if a black pixel with noise or more is detected from that area, end the check and control the inspection result that the printing result is bad Output to the unit 600. Also, for example, the ruled line information stored in the format information storage unit 507 is obtained, and the inspection image storage unit 4
A 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 an area where characters are printed is scanned in the character string direction, black and white pixels frequently change. Therefore, it can be detected that characters are printed there. By such a method, it is checked whether or not the character is printed in the area where the character should be printed. In addition, a check is made to see if the table is properly located where the table should be, and if the mark is properly located. At the time of inspection using this structural analysis method, an inspection result indicating that the printing result is defective is output to the control unit 600 immediately after the inconsistency is detected, and the subsequent processing ends.

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, and is stored in the print image storage unit 240. The matching process between the original image data and the inspection image data stored in the inspection image storage unit 460 is performed.
Then, the number of error pixels input from the error number counter 506 is compared with the threshold value THL, and the number of error pixels is
If it is larger than HL, it is determined that the printing is defective, and if the matching is completed without exceeding the threshold value THL, it is determined that the printing is normal.

Before performing these inspections, the CPU 5
At 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 upper pixel where the cue mark of both image data is detected Or take action based on
Processing such as detecting the center of gravity of both black pixels and determining the corresponding pixel based on the point is performed. 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. The control unit 600 has an Ethernet I / F in the control unit 600,
Printing conditions and control conditions are input from an upper host computer. 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 based on the input data, transports the print paper, prints on the print paper, and prints the printed image. Make sure that loading is synchronized and appropriate. Also,
The control unit 600 controls the paper transport unit 110a and the printing unit 200 so as to immediately stop the printing operation when a signal indicating a printing failure is input from the inspection unit 500 during the printing operation. .

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

Next, the operation of the printer 1 will be described with reference to FIG.
This will be described with reference to FIG. FIG. 12 is a diagram illustrating a state in which image data is printed on printing paper 800 that is continuous paper by the printer device 1. The print target shown in FIG.
For example, it is a bill such as a telephone charge, and the 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
You can know the break position of each invoice. FIG. 12 is a diagram illustrating a printing state of one surface of the printing paper 800, but the same printing is performed on the back surface.

Hereinafter, such an invoice is sent to the printer 1
The operation of the printer 1 will be described for the case of printing with. First, the operation unit 610,
Alternatively, the user inputs print contents, print conditions, and the like via the host computer. Accordingly, the control unit (not shown) sets the operating conditions of the front printer unit 1a, the back printer unit 1b, the paper transport unit 110, and the like. When the setting of the conditions is completed, the actual printing operation can be started. Printing paper 800 from the paper roll feed unit 110 _-1 with the being sequentially supplied in Table printer unit 1a, are input sequentially printing bitmapped image data via the interface unit 250 in Table printer unit 1a, print image It is stored in the storage unit 240. Then, the image data stored in the print image storage unit 240 is
00 is read and printed on the supplied printing paper 800. As a result, as shown in FIG.
1. Billing information 802 and billing details 803
Invoices having items of _{-1 to} 803 _-3 are sequentially printed.

At this time, the non-print area extracting unit 260
Reads out the image data stored in the print image storage unit 240 and detects a non-printing area not covered by the bitmap data in the area on the printing paper 800. Thus, in the example shown in FIG. 12, for example, including margins 808 _-2 between the first page and the margins 808 _-1 and 2 pages and third page between the second page, unprinted An area 808 is extracted.

The image printed on the printing paper 800 is read by the image reading unit 400 and stored in the inspection image storage unit 460. Inspection image storage unit 46
The image data stored in the monitor 47 is supplied to the inspection unit 500 for inspection of the printing state,
Output to 0.

In the inspection section 500, first, the printing paper
Non-printing detected by non-printing area extraction unit 260 on 800
In a region corresponding to the region 808, a black band streaker exists.
Inspect 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 printed in the sub-scanning direction of the printing paper 800.
Scan. Then, in the area where the black pixel is predetermined
If the black band streaker is
And it is determined that the number of print heads is equal to or more than that. What
Note that this threshold takes into account the magnitude of noise that can occur
To decide. And it is judged that there is a black belt streamer.
If specified, immediately indicates that the print status is not appropriate.
Is output to the control unit 600, and the control unit 600
The printing process is stopped. In the example shown in FIG.
Black belt streaker 810 occurs after the middle of the page
I have. In such a case, the second and third pages
Margin 808 between _-2Scans the black band streaker 8
10 is detected and the signal indicating that the printing status is not appropriate is controlled
The output is output to the unit 600, and the printing process ends.

If no black band streaker exists in the non-print 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 inspection. Whether it has structural features consistent with the format information, that is, as described above, a predetermined blank area, a character string,
It is checked whether ruled lines and the like exist properly. At the time of 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 last inspection, the print image data stored in the print image storage unit 240 and
The matching with the inspection image data stored in the inspection image storage unit 460 is performed. Both images are collated sequentially with the compressed image or the original image, and if there are more than a predetermined number 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. The control unit 600 instructs the sheet conveying unit 110 and the printing unit 200 to stop the processing, and immediately stops the printing operation, as in the other inspections so far. If all of these three stages of inspection are cleared, it is determined that printing has been properly performed, and printing is continued.

The printing paper 800 that has passed through the front printer unit 1a and has the desired image data printed on the front surface is turned upside down by the paper reversing unit _110-7 , and the back printer unit 1
b. The back printer unit 1b includes the front printer unit 1
The desired image data is printed on the back surface of the printing paper 800 by the same operation as in a, and the inspection is performed. As a result, if 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 apparatus 1 of the present embodiment, the blank area not covered by the print image data is set as the non-print area, and this area is scanned in the sub-scanning direction to detect the black band streaker. doing. Therefore, the black belt streaker can be detected by simple processing to detect an abnormality of the print head, and defective printing can be detected quickly. In particular, such a black band streaker often occurs in an ink jet printer such as the printer 1 and is more effective in such a printer. Further, since the non-printing area is extracted by the non-printing area extracting unit based on the input image data, the control of the printer device 1 and the scanning are not complicated. It can be used with the same operability as a printer device.

In the printer 1, after the inspection based on the non-print area, the printing state is inspected by further extracting the structural features of the printer image data based on the format information of the print image data. As a result, for example, a streaker or a white spot generated in the print area is effectively detected, and the inspection of the print state can be effectively performed. Then, in the printer device 1, after the inspection based on the structural characteristics, the printing state is further inspected by performing template matching between the print image data and the inspection image data. As a result, small differences such as differences in print contents are also accumulated and extracted, and the printing state can be inspected more effectively and accurately. As described above, in the printer device 1, the three-stage inspection is performed on each printed matter,
The printing state can be inspected from various aspects, and defective prints can be appropriately detected and eliminated, and accurate and high-quality prints can be output.

Further, in the printer device 1, when a defective print is found, the operation of the printer device 1 is immediately stopped, so that the occurrence of defective prints can be minimized, and time and printing resources can be reduced. Such waste as possible can be reduced as much as possible.

The present invention is not limited to the present embodiment, and various modifications are possible. 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 a third inspection by matching to check the printing state. But,
Such an inspection is not essential, and any method other than the first inspection using the information on the non-printing area according to the present invention may be used. The second inspection and the third inspection may be omitted, or a new inspection may be performed, based on experience such as reliability of the print head and a problem that occurs. Also, arbitrary information and method may be used as the format information of interest and the matching method.

In the first inspection method based on the information of the non-printing area performed by the inspection section 500, in the present embodiment, the image data is scanned in the sub-scanning direction of the printing paper 800, and the black image is scanned. The continuation of pixels was performed. This method is very effective for detecting black band streakers that often occur in ink jet type heads, etc.
This is not limited to this method either. For example, similar streaker detection may be performed in the main scanning direction, or scanning may be performed in an arbitrary direction to extract blocks of a predetermined number or more of black pixels. By doing so, it is possible to detect, for example, a drop of ink that has dropped in a dot-like manner, and it is possible to detect more than a wider range of print heads.

The printing medium on which printing is performed in the printer 1 is not limited to continuous paper as shown in the present embodiment, but may be cut paper or a printing medium of a material other than paper. You may. Even when the print medium is cut paper as shown in FIG. 13, the non-print area extraction unit 260 extracts a non-print area similar to 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.

In this embodiment, the non-print area extracting section 260 detects an area on the printing paper 800 which is not covered by the bitmap data stored in the print image storage section 240, and Area. However, the contents of the bitmap data may be further analyzed, a margin area may be extracted from the data, and the margin area may 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 stores an area 8
Bitmap data for each of 01 to 803 is stored, and in the above-described embodiment, an area other than these areas is extracted as the non-print area 808. But,
Further analyzing the contents of each bitmap data,
For example region 803 _-2 it is composed of a series of character blocks 809 _-2 and 809 _-3, margin areas 8 therebetween
It can be extracted that _08-3 exists. Therefore,
The non-printing area extracting unit 260 may analyze up to the contents of the bitmap data to extract these blank areas, and may set them as non-printing areas that can be referred to by the inspection unit 500. With such a configuration, the detection of the black band streaker can be performed with higher accuracy, and the black band streaker generated in the area covered by the image data can be quickly found.

Further, in the printer 1 of the present embodiment, the printable width is substantially 8 inches by using two print heads 220 and two CCD cameras 440 respectively. However, the print width may be set to 16 inches using, for example, four print heads 220 and the CCD camera 440, and the print head 220 and the CCD camera 440 may be used.
The number and print width of the cameras 440 may be in any form according to the printing target. In the printer 1 of the present embodiment, the front printer 1a and the back printer 1
The two-sided printing that prints on both the front and back sides of the printing paper 800 was performed using b. However, it is clear that the present invention can be applied to single-sided printing. In that case, the sheet reversing unit _110-7 and the back printer unit 1b become unnecessary, and the configuration becomes simpler.

Further, in this embodiment, the printer 1 is stopped immediately when a defective print is detected, but a measure after the detection of the defective print may be arbitrarily determined. For example, the printer device 1 may be stopped when defective printing occurs to some extent continuously. A black band streaker temporarily generated by the inkjet head may be naturally restored after a while. If recovery of such printing failures is expected, and once the printer device is stopped, the process of restarting the printer is complicated and takes a long time. In some cases, printing can be performed more efficiently if the printing is continued. In such a case, the configuration may be such that the printer is not stopped immediately and the printer is continuously operated as much as possible. At this time, the conditions for stopping the printer device 1 and the like may be arbitrarily determined.

If such a printer is not stopped immediately, a defective print is identified or
In order to appropriately eliminate defective prints, it is necessary to be able to easily identify a print determined to be defective afterwards. For this purpose, it is desirable to display the identification code, the bill number, and the like on the monitor 470, for example.

Further, a configuration may be employed in which some marking is performed on a printed matter determined to be defective.
FIG. 15 shows a schematic external view of the printer 1b having such a configuration. A printer device 1b shown in FIG. 15 has a print width of 16 inches using four print heads 220 and four CCD cameras 440, and is a printer device for performing only one-sided printing. In the printer device 1b, a defective printing marking unit having a printing head 631 for filling and a printing head 632 for a defective display mark is provided at a stage subsequent to 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 a printed material determined to be defective printing.

That is, the defective display mark print head 63
2 prints an error code 822 consisting of a predetermined character string so that the cause of the defective printing can be understood, or prints the address 801 of the printed matter by the printing head 631 for filling.
Or a fill pattern 821 that invalidates. The error code 822 is a bar code,
OCR characters and arbitrary figures may be used. In addition, in contrast to the description clearly indicating that the printed matter has no effect described in advance, by marking and indicating that the description is valid, the printed matter is excluded as a defective printed matter. Is also good. As described above, the treatment after detecting the printing failure may be performed by any method.

Further, the printer 1 of the present embodiment
The non-print area extracting 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 from a host computer or the like together with print image data. With such a configuration, a storage unit for storing the input data indicating the non-printing area is required, but the non-printing area extraction unit 260 is not required.
The device configuration is simplified. It is clear that the printer 1 having such a configuration is also within the gist of the present invention which examines the presence of the black band streaker in the non-printing area.

In this embodiment, the inspection unit 5
The inspection result of “00” was once input to the control unit 600, and based on a control signal from the control unit 600, for example, a process such as a stop of a printing operation was performed in the sheet conveying unit 110 or the printing unit 200. However, when processing is concentrated on the control unit 600, a time lag may occur if a signal is transmitted via the control unit 600, and the device may not be able to be stopped immediately. In such a case, the inspection section 500 sends the sheet to the sheet transport section 110 or the head 220.
A signal for directly stopping the processing when a printing failure is detected may be sent to a related component such as the above.

Further, the present invention is not limited to a printer which prints in two black and white colors, such as the printer of the present embodiment, and performs multi-value printing, multi-color printing, or full-color printing. The present invention is also applicable to a printer device. Further, a printer device that performs front and back printing may be used. Other signal processing, signal transmission paths, and the like may be arbitrarily and suitably modified within the scope of the present invention.

[0075]

According to the printer apparatus of the present invention, a print defect can be detected easily, quickly and accurately, and when a print defect occurs, for example, measures such as stopping the printer apparatus can be taken immediately. . As a result, it is possible to prevent a decrease in efficiency such as the occurrence of a large number of defective prints, to efficiently perform normal printing, and to provide a highly reliable printer capable of performing accurate and high-quality printing at high speed. .

[Brief description of the drawings]

FIG. 1 is a schematic external view of a printer apparatus main body according to an embodiment of the present invention, in which (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 illustrating a configuration of a printing unit of the front printer unit illustrated in FIG. 2;

4A and 4B are diagrams showing the arrangement of the print head and the CCD camera of the front printer unit shown in FIG. 2, wherein FIG. 4A shows the arrangement of the print head and FIG. 4B shows the arrangement of the CCD camera; FIG.

FIG. 5 is a diagram illustrating the structure and operation principle of a head of a printing unit illustrated in FIG. 3;

FIG. 6 is a diagram showing a printing state by the head shown in FIG. 5;

7 is a diagram illustrating a configuration of an image reading unit of the front printer unit illustrated in FIG. 2;

FIG. 8 is a diagram illustrating a configuration of an encoder unit of the image reading unit illustrated in FIG. 7;

FIG. 9 is a diagram illustrating a configuration of a CCD camera of the image reading unit illustrated in FIG. 7;

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 illustrating a configuration of an inspection unit of the front printer unit illustrated in FIG. 2;

FIG. 12 is a diagram illustrating image data printed on printing paper that is continuous paper by the printer device illustrated in FIG. 1;

13 is a diagram illustrating image data printed on a printing sheet, which is a cut sheet, by the printer illustrated in FIG. 1;

FIG. 14 is a view showing a print image for illustrating a modification of the operation of the non-print area extracting unit of the front printer unit shown in FIG. 2;

15A and 15B are external views for describing a printer device according to a modification of the present embodiment, where FIG. 15A is a side view and FIG. 15B is a top view.

FIG. 16 is a view for explaining marking on a printed material as a modification of the treatment when a printing failure is detected.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printer apparatus, 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 unit, 600: control unit, 610: operation unit, 800: printing paper

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tsutomu Yoneda 1-2-4-102 Hakusan, Aso-ku, Kawasaki City, Kanagawa Prefecture (56) References JP-A-4-319471 (JP, A) JP-A-6- 286275 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/01 B41J 29/46 G06F 3/12

Claims (5)

(57) [Claims] 1. A printer for printing sequentially input data.
An apparatus for printing input image data on a printing medium
Means for reading an image on the printed medium to be printed
Sensor means, and the read image data,
For image data in the area corresponding to the non-print area,
Valid print pixels in the sub-scanning direction are continuous for a predetermined number or more.
Check if there is a sequence of valid print pixels
In such a case, by determining that the printing state is inappropriate,
Inspect the status of the printing and make sure the printing is done properly
A printer device having an inspection unit for determining whether or not the printing is performed . 2. The apparatus according to claim 1, wherein said inspection means further comprises:
Structural features are extracted from the image data
Refer to the format information of the
Check whether the extracted features are appropriate, and check that the printing is appropriate.
The printer according to claim 1, wherein it is determined whether or not the printing has been performed.
apparatus. 3. The inspection means further comprises:
Image data, and the read image data
Template matching, detect their differences,
Whether the printing was properly performed based on the amount of the difference
The printer device according to claim 1 , wherein the determination is made . 4. The printing means prints by the inspection means.
Stop printing when it is determined that the status is inappropriate
The printer device according to claim 1. 5. The printer according to claim 1, wherein said inspection means determines that the printing state is inappropriate.
Printing that, if determined, substantially disables the printing
And a second printing means for further printing on the printing medium.
The printer device according to any one of claims 1 to 4, further comprising:
Place.