JP2003145734A - Bar code recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that when a bar code label, or the like, is printed at a relatively high speed, a sheet is passed below a recording head wider than the print width of a recording medium and the image is recorded by single scanning and when an unsound or failed nozzle occurs in a recording head comprising a large number of nozzles, an error may occur at the time of reading out a bar code and such a phenomenon inherent to a specific nozzle has a trend of occurring continuously. SOLUTION: When an unsound or failed nozzle exists, the number of a failed nozzle is specified by test print using an incorporated scanner and the recording position of a bar code is shifted. Alternatively, error is prevented at the time of reading out a bar code by rotating the bar code by 90 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for recording an image on a recording medium using a recording head.

[0002]

2. Description of the Related Art FIG. 9 shows an example of white stripes generated when a bar code is printed when an unhealthy nozzle is present in the prior art. Usually, in the case of this type of printing, a bar code or the like is printed by scanning only once by passing a sheet under a recording head having a width larger than a printing width of a recording medium. Therefore, if an unhealthy nozzle or a defective nozzle occurs in the recording head composed of a large number of nozzles, white streaks as shown in FIG. 9 occur. Such a phenomenon is often a problem specific to a particular nozzle, and tends to occur continuously.

[0003]

When an unhealthy nozzle or a defective nozzle occurs in a recording head of an ink jet recording system, it usually causes a white stripe, but if it overlaps with the recording position of a bar code, it is a recorded matter. It may cause an error when reading with a barcode reader.

[0004]

When the next printing operation is performed, it is judged whether or not the defective nozzle # and the portion such as the bar code overlap each other. If they do, the bar code By shifting the printing position or rotating it by 90 degrees, it is possible to avoid printing defects such as white stripes in advance. In order to solve the problem, the present invention carried out the means described in (1) to (4) below. (1) A recording head having a plurality of nozzles, a paper feeding unit for supplying a recording medium and a conveying unit for conveying the recording medium, a judgment unit for judging an unhealthy nozzle number of the recording head, the judgment unit A printer having a storage unit for storing a sound nozzle number and a unit for changing the print content based on the contents of the storage unit. (2) The printer according to (1) is characterized in that the recording position of the bar code is shifted to change the recording content. (3) The printer according to (1) is characterized in that the change of the recorded contents is to rotate the bar code by 90 degrees. (4) The printer according to (1) is characterized in that the change of the recorded contents is that the bar code is rotated by 90 degrees and further shifted.

[0005]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic front view of a color printer embodying the present invention. A long roll paper 11 to which recording media 16 are attached at equal intervals is set in the paper feed unit 10 and sent to the printer body 12.

A recording head 89 is arranged in the printer main body 12 in a direction perpendicular to the sheet advancing direction. In this embodiment, the black, cyan, magenta and yellow heads are arranged in parallel. The sheet is conveyed by the conveyor belt 14 by the driving force of the conveyor roller 13. Recording head 8
Each of the nozzles 9 is connected to an independent ink cartridge 15 through a tube (not shown) or the like, and a large number of nozzles of the recording head 89 are selectively heated based on a recording signal to eject ink to perform color recording. .

A scanner 92 is provided downstream of the recording head 89.
Is used as an input means for identifying a defective nozzle by detecting a density drop after recording.

FIG. 2 shows the positional relationship between the recording medium 16, the recording head 89, and the scanner 92 when viewed from above the recording unit. If there is a defective nozzle, it can be identified by stopping the non-ejection detection pattern 17 under the scanner 92. FIG. 8 and FIG. 9 show examples that appear in an image when a non-ejection nozzle is present. As an inkjet nozzle characteristic, unhealthy nozzles and non-ejection nozzles tend to continuously occur as shown in the figure.

FIG. 3 is a block diagram showing the control unit 80 of the recording apparatus embodying the present invention. CPU 81 of control unit 80
Receives and reads recording data from the host computer 82 through the interface 83, and the work RAM 8
5. Temporarily expand and store in 5. In the case of recording data including characters and bar code, the CPU 81 receives the code data, the recording start position, etc., and then, from the character / bar code character generator CGROM 86, the bitmap data. The data may be read out and expanded in the recording buffer area of the work RAM 85.

When the expansion is completed, the CPU 81 drives an actuator (not shown) such as a motor through the output port 90 and the driver circuit 91 to start the recording operation. The CPU 81 temporarily starts the reading of the recording data stored in the work RAM 85 and stores it, and starts the recording control circuit 8.
The recording data is sequentially transferred to the recording head 89 via 8 and color recording is performed on the recording medium. In the case of the present invention, the recording head 8
9 is composed of four independent heads (black, cyan, magenta, yellow). Each head is capable of recording wider than the maximum recording width of the recording medium. These series of operations are executed by the CPU 81 based on the program stored in the program ROM 84. The CPU 81 also uses another area of the work RAM 85 as a work memory required for execution.

The characteristic determination of the unhealthy nozzle # of the present invention will be described mainly based on FIGS. 3 to 6. Eg 1
Before the first recording operation of the day or before a special large amount of recording operation, the printer receives a test pattern recording command in order to identify the presence or absence of defective nozzles and the defective nozzle #. Then, the operation of the flow chart of FIG. 5 is started, and the recording of the test pattern is executed (S101). The recording portion of the non-ejection detection pattern 17, which is a test pattern, is controlled to stop below the scanner 92. Next, the CPU 81 in FIG. 3 outputs the output port 90,
Turn on the light source for the scanner 92 via the driver circuit 91.
Yes (S102). Continuing, the CPU 81 is the scanner 92
To send a scan command to the test pattern unit (103). The scanner 92 outputs the measured density data for each scanning position via the AD converter 93 shown in FIG. 3, and the CPU 81 sequentially reads the converted digital value (S104).

As a result, when there is a defective nozzle or an unhealthy nozzle, for example, as shown in FIG. 4, a point having a value equal to or lower than the predetermined recording density is detected for each position in the print width (recording width) direction. (S105), the CPU 81 causes the defective nozzle #
Is specified and stored in the work RAM 85 (S106). Figure 4
In the example of, one nozzle is detected. The detection result is not always limited to one nozzle, and a plurality of detection results may occur simultaneously. The defective nozzle may be stored in the recording head 89 or a non-volatile memory (not shown) in the control unit 80 in order to keep a history. In order to inform the operator of the presence of the defective nozzle, the CPU 81 outputs an alarm (S
107) The determination operation ends. Due to the output alarm, the operator is in the process of starting recording from the bar code.
Know in advance that the printer may automatically change the recording position such as the code. When it is troublesome to change the recording position, the operator may interrupt the next operation instruction.

[0013]

[Embodiment 1] FIG. 6 shows a flow chart of a recording operation on the premise that the existence of the defective nozzle is detected in advance. When a print job is started (S20
1) The CPU 81 checks whether the recorded contents include a bar code, and if the bar code is included (S202), the bar code is recorded.
It is determined whether or not the bad portion and the defective nozzle # overlap, and if they overlap (S203), the horizontal shift amount of the bar code is calculated (S204). The outline of the calculation method is shown in FIG. For example, if the nozzle # corresponding to the left end of the bar is γ and the defective nozzle # is αi, the shift amount is to the right (αi-γ),
Alternatively, if the bar width is β, the nozzle # corresponding to the right end of the bar may be shifted to the left by (γ + β)-(γ + β) -αi. The CPU 81 selects one of the two methods with the smaller absolute value of the shift amount, shifts the buffer address of the corresponding bar code area in the print buffer of the work RAM 85, and updates the print buffer. (S20
5).

[0014]

[Embodiment 2] In Embodiment 1, the direction in which the image is displaced is the direction perpendicular to the carrying direction, but the entire bar code area is 90 degrees (or -90 degrees is acceptable) as shown in FIG. You may rotate. In the first embodiment, the bar code position shift amount is calculated (S204) by the flow chart of FIG. 6, but in the present embodiment, instead, the bar code 90 degrees (or -9).
The print buffer may be updated after the rotation processing (0 degree) (S205). It is preferable to rotate the image so that the bar code is not placed at the location of the discharge nozzle, but in this method, even the bar code containing white lines as shown in FIG. 11 is compensated by the function of the reader at the time of reading. It can be functionally sufficient.

[0015]

[Other Embodiments] The rotation method of the second embodiment may be combined with the first embodiment in which the position of the bar code is displaced so that the non-ejection nozzle does not overlap the bar portion.

[0016]

As described above, in the case of recording a bar code with a line head having a defective nozzle or an unhealthy nozzle, a method of shifting the recording position in the lateral direction of the bar code or rotating by 90 degrees By performing the method described above and the method combining the two methods, a reliable bar code recording can be obtained.

[0017]

[Brief description of drawings]

FIG. 1 is a schematic view of a printer showing an embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship among a recording medium, a recording head, and a scanner of the present invention.

FIG. 3 is a block diagram of a control unit of the present invention.

FIG. 4 is an example showing a scanner reading result of a non-ejection detection pattern.

FIG. 5 is an operation flowchart for identifying and storing a defective nozzle #.

FIG. 6 is an operation flow chart for calculating a bar code shift amount in the first embodiment of the invention.

FIG. 7 is a diagram showing a positional relationship between a bar code and a defective nozzle # and a shift method.

FIG. 8 is an example of an image when ejection failure occurs.

FIG. 9 is an example of an image when ejection failure occurs in a barcode recording portion.

FIG. 10 is a recording example in which rotation processing is performed in the second embodiment of the invention.

FIG. 11 is a recording example in which a non-ejection portion appears after rotation processing in the second embodiment of the invention.

[Explanation of symbols]

10 Paper feeder 11 roll paper 12 Printer body 13 Transport roller 14 Conveyor belt 15 ink cartridge 16 recording media 17 Non-discharge detection pattern 80 Control unit 81 CPU 82 Host PC 89 recording head 92 Scanner 93 AD converter (A / DC)

Claims (4)

[Claims] 1. A recording head having a plurality of nozzles for ejecting ink, a paper feeding portion for supplying a recording medium, a conveying portion for conveying the recording medium, and a judgment means for judging an unhealthy nozzle number of the recording head. A printer having a storage unit that stores the determined nozzle number and a unit that changes the print content based on the content of the storage unit. 2. The printer according to claim 1, wherein the change of the print contents is to shift the print position of the bar code. 3. A bar code is used to change the recorded contents.
The printer according to claim 1, wherein the printer rotates once. 4. The change of the recorded contents is a bar code 90.
The printer according to claim 1, wherein the printer rotates once and then shifts.