JP4123775B2 - Printing apparatus and dot formation determination method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing apparatus, a dot formation determination method, a computer program, a recording medium, a computer system, a test pattern area, and a test pattern area printing method.
[0002]
[Background]
A color inkjet printer, which is a typical printing apparatus, is already well known. This color ink jet printer includes an ink jet print head that ejects ink from nozzles, and is configured to record images, characters, and the like by landing ink droplets on printing paper as an example of a printing medium. Yes.
[0003]
The print head is supported by the carriage with the nozzle surface on which the nozzles are formed facing the print paper, and moves (main scan) in the width direction of the print paper along the guide member. Ink droplets are ejected in synchronization with.
[0004]
By the way, there are cases where the nozzles formed on the print head are clogged and ink droplets cannot be ejected due to an increase in the viscosity of the ink or mixing of bubbles. When the nozzles are clogged, so-called dot dropout occurs in the image, causing deterioration in image quality.
[0005]
Therefore, a function for inspecting whether or not dots are formed normally by ejecting ink droplets is required.
[0006]
Several methods have been proposed to realize this function, but light is emitted from a light-emitting device that forms dots on a printing sheet and prints a test pattern, and the test pattern includes a light-emitting diode or the like. The reflected light reflected by the test pattern is received by a light receiving sensor such as a photodiode (hereinafter also referred to as a light receiving unit), and the output value of the light receiving sensor corresponding to the intensity of the received reflected light is compared with a threshold value. There is a method for determining whether or not the dot formation has been normally performed. In other words, even if the same intensity of light is applied, it is possible to utilize the fact that the intensity of the reflected light received is different between the location where the dot formation is normally performed on the printing paper and the location where the dot formation is not performed normally. It is determined whether or not dot formation has been performed normally.
[0007]
By the way, in order to determine whether or not the dot formation has been normally performed with high accuracy, the irradiation area of the light emitted to the test pattern is individually determined by the test pattern formed for each nozzle as an example of the dot forming means. It is desirable that the region be irradiated. However, in order to realize such an irradiation region, the cost of the light emitting device becomes high due to factors such as the need for a high-performance lens for narrowing the irradiation beam. Therefore, in order to realize cost reduction, a light emitting device having an irradiation region that spans several test patterns is used.
[0008]
Reference is now made to FIG. FIG. 14 is a conceptual diagram showing a test pattern formed for each nozzle and a light irradiation area by a light emitting device. The 8 × 8 squares partitioned on the drawing schematically represent the test pattern formed for each nozzle. Further, the three circles shown in the drawing schematically represent the light irradiation area and its position by the light emitting device.
[0009]
Problems that arise when using FIG. 14 to determine whether or not dots are formed normally by applying light to a test pattern formed for each nozzle by a light emitting device having an irradiation area that spans several test patterns. Is described below.
[0010]
As described above, the light emitted from the light emitting device is applied to the test pattern, the reflected light reflected by the test pattern is received by the light receiving sensor, and the output value of the light receiving sensor corresponding to the intensity of the received reflected light is set as a threshold value. In general, the threshold value is determined based on the light receiving sensor output value when the dot formation is performed normally and the light reception when the dot formation is not performed normally. It is set to be between the sensor output values.
[0011]
When the determination is performed by a light emitting device having an irradiation region that individually irradiates a test pattern formed for each nozzle, the threshold value may be a constant value for each test pattern to be determined. On the other hand, in the case where the determination is performed by a light emitting device having an irradiation area that spans several test patterns, whether the dot formation is normal in the upper left, lower left, and lower right test patterns shown in FIG. Regardless, the output value of the light receiving sensor differs depending on the intensity of the reflected light. Therefore, if a determination is to be made accurately, it is necessary to provide a separate threshold value for each test pattern.
[0012]
In other words, while the lower right test pattern is completely filled with other test patterns, the upper left and lower left test patterns are adjacent to the so-called paper background, so that a portion of the paper background is formed in the irradiation area. Will be included. Accordingly, since the output value of the light receiving sensor differs for each test pattern, there is a trouble that the threshold value must be set in detail in consideration of this point.
[0013]
In addition, if each test pattern is made sufficiently large so that a relatively large irradiation area by the light emitting device realized at low cost is within the area of the test pattern, the above problem is solved, but in this case, Another disadvantage is that the entire area of the test pattern becomes large and the time for inspecting the presence or absence of missing dots becomes long.
[0014]
[Problems to be solved by the invention]
The present invention has been made in view of such problems, and the object of the present invention is to provide a printing apparatus, a dot formation determination method, a computer program, and a recording that accurately determine whether or not dot formation has been performed normally. To realize a medium, a computer system, a test pattern area, and a test pattern area printing method.
[0015]
[Means for Solving the Problems]
The main present invention has a print head provided with a plurality of dot forming means for forming dots, and prints a test pattern by forming dots on a printing medium for each of the dot forming means. The light receiving sensor emits the light reflected by the printing medium, and the dot forming means determines the output based on the output value of the light receiving sensor according to the intensity of the received reflected light. In a printing apparatus that determines whether or not dot formation has been performed normally, among the test patterns, when the dot formation is performed normally, the front side and the rear side in the main scanning direction and the sub-scanning direction are different. The printing apparatus is characterized in that the determination is performed only on a test pattern on which the test pattern is printed.
[0016]
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
=== Summary of disclosure ===
At least the following will be made clear by the description of the present specification and the accompanying drawings.
[0018]
A printing head having a plurality of dot forming means for forming dots, forming a dot on a substrate to be printed for each dot forming means, printing a test pattern, and emitting light toward the test pattern; The reflected light of the emitted light is received by the light receiving sensor, and the dot formation by each dot forming means is normal based on the output value of the light receiving sensor according to the intensity of the received reflected light. In the printing apparatus that determines whether or not the test has been performed, when the dots are formed normally among the test patterns, other test patterns are printed on the front side and the rear side in the main scanning direction and the sub-scanning direction. The above-described determination is performed only on the test pattern to be printed.
[0019]
Of the test patterns, the determination is performed only for test patterns in which other test patterns are printed on the front side and the back side in the main scanning direction and the sub-scanning direction when the dot formation is performed normally. As a result, it is possible to accurately determine whether or not dots are formed normally without necessarily providing separate threshold values for each test pattern.
[0020]
In addition, a first region configured by a predetermined test pattern array and a second region configured by a test pattern array similar to the first region at a position adjacent to the first region in the sub-scanning direction A third region constituted by an array of test patterns similar to the first region at a position adjacent to the first region in the main scanning direction, adjacent to the second region in the main scanning direction, and A fourth area constituted by a test pattern array similar to that of the first area is printed at a position adjacent to the third area in the sub-scanning direction by forming dots on the substrate to be printed. Among the test patterns in one region to the fourth region, a test pattern in which other test patterns are printed on the front side and the rear side in the main scanning direction and the sub-scanning direction when the dots are formed normally. Only it is also possible to perform the determination as target.
[0021]
In this way, a test pattern for achieving the above-described effect that it is possible to accurately determine whether or not dot formation has been normally performed without necessarily providing a separate threshold for each test pattern. Can be easily realized.
[0022]
A fifth area configured by a predetermined test pattern arrangement; and a test pattern arrangement similar to an upstream portion of the fifth area in the sub-scanning direction, and the downstream of the fifth area in the sub-scanning direction. A sixth region configured to overlap the portion, and an array of test patterns similar to the region of the fifth region excluding the upstream portion, and overlapping the region of the fifth region excluding the downstream portion. A seventh region configured in the same manner; an eighth region configured by an array of test patterns similar to the fifth region at a position adjacent to the fifth region in the main scanning direction; and sub-scanning of the eighth region A ninth region having the same test pattern arrangement as that of the upstream portion in the direction and overlapping the downstream portion of the eighth region in the sub-scanning direction, and a region excluding the upstream portion of the eighth region the same as A tenth area having a test pattern arrangement and overlapping with an area excluding the downstream portion of the eighth area, and forming dots on the substrate to be printed; Of test patterns in the tenth region, only test patterns in which other test patterns are printed on the front side and the back side in the main scanning direction and the sub-scanning direction when the dot formation is performed normally The determination may be performed as follows.
[0023]
In this way, since the entire area of the test pattern to be inspected is further reduced, in addition to the above two effects, there is a merit that the time for inspecting the presence / absence of dot omission becomes shorter.
[0024]
Alternatively, two or more dots may be formed in the sub-scanning direction and the test pattern may be printed on the substrate.
[0025]
In this way, since the density of the test pattern when dots are formed normally is higher, the light receiving sensor output value when dots are formed normally and the light reception when dots are not formed normally The difference from the sensor output value becomes larger, so that it is possible to accurately determine the presence or absence of missing dots.
[0026]
The test pattern printed for each dot forming unit may be printed in the same color.
[0027]
In this way, it is possible to eliminate the non-uniform density of each test pattern due to different colors for each test pattern, and therefore, it is not always necessary to provide a separate threshold for each test pattern. It is possible to accurately determine whether or not dot formation has been performed normally.
[0028]
The dot forming means may be a nozzle for ejecting ink to form dots.
[0029]
In a so-called ink jet printing apparatus that performs printing by ejecting ink from a print head, a high image quality of the printing result is particularly required, so that the merit of the above means is further increased.
[0030]
A step of printing a test pattern by forming dots on a printing medium for each of a plurality of dot forming means for forming dots provided on a print head, and a step of emitting light toward the test pattern. Receiving the reflected light of the received light by the printing medium with a light receiving sensor, and forming dots normally by each dot forming means based on the output value of the light receiving sensor according to the intensity of the received reflected light And a step of determining whether or not it has been performed, and a dot formation determination method comprising: a front side and a back side in the main scanning direction and the sub-scanning direction of the test pattern when the dot formation is performed normally. A dot formation determination method, wherein the determination is performed only on a test pattern on which another test pattern is printed.
[0031]
Of the test patterns, the determination is performed only for test patterns in which other test patterns are printed on the front side and the back side in the main scanning direction and the sub-scanning direction when the dot formation is performed normally. As a result, it is possible to accurately determine whether or not dots are formed normally without necessarily providing separate threshold values for each test pattern.
[0032]
It is also possible to realize a computer program for causing the printing apparatus to execute the above dot formation determination method.
[0033]
It is also possible to realize a computer-readable recording medium on which a computer program for causing the printing apparatus to execute the above dot formation determination method is recorded.
[0034]
It is also possible to realize a computer system having a computer apparatus main body and the above-described printing apparatus connectable to the computer apparatus main body.
[0035]
In addition, the first region is configured in a first region configured by a predetermined array of test patterns formed by ejecting ink from a predetermined nozzle, and at a position adjacent to the first region in the sub-scanning direction. A second region configured by an array similar to the first region of the test pattern formed by ejecting ink from a nozzle similar to the nozzle for forming the test pattern, and the first region and the main scanning direction Is formed by an arrangement similar to the first area of the test pattern formed by ejecting ink from the same nozzle as the nozzle for forming the test pattern constituting the first area at a position adjacent to the first area. The test pattern constituting the first area is formed at a position adjacent to the third area, the second area in the main scanning direction, and adjacent to the third area in the sub-scanning direction. A fourth area constituted by the same arrangement as the first area of the test pattern formed by ejecting ink from the same nozzle as the nozzle for printing is printed by ejecting ink on the printing medium. It is also possible to realize a test pattern area.
[0036]
In addition, a test pattern for each nozzle may be formed by ejecting ink from all nozzles provided in the print head, and the test pattern for each nozzle may be included in the first region.
[0037]
In this way, it is possible to realize a test pattern area for performing determination on whether or not ink ejection has been normally performed for all the nozzles.
[0038]
In order to form a fifth area constituted by a predetermined arrangement of test patterns formed by ejecting ink from predetermined nozzles and the test pattern constituting an upstream portion of the fifth area in the sub-scanning direction. The sixth area having the same arrangement as the upstream part of the test pattern formed by ejecting ink from the same nozzle as the nozzles of the fifth area and overlapping the downstream part in the sub-scanning direction of the fifth area And the test pattern formed by ejecting ink from a nozzle similar to the nozzle for forming the test pattern constituting the region excluding the upstream portion of the fifth region, excluding the upstream portion. A seventh region having the same arrangement as the region and configured to overlap the region excluding the downstream portion of the fifth region, and a position adjacent to the fifth region in the main scanning direction An eighth region configured by an array similar to the fifth region of the test pattern formed by ejecting ink from a nozzle similar to the nozzle for forming the test pattern configuring the fifth region; The test pattern formed by ejecting ink from the same nozzle as the nozzle for forming the test pattern constituting the upstream portion in the sub-scanning direction of the eighth region has the same arrangement as the upstream portion. , The ninth region configured to overlap with the downstream portion in the sub-scanning direction of the eighth region, and the nozzle for forming the test pattern constituting the region excluding the upstream portion of the eighth region The test pattern formed by ejecting ink from the nozzles has the same arrangement as the region except for the upstream portion, and excludes the downstream portion of the eighth region. A tenth region constituted overlaps the region, but it is also possible to realize a test pattern area printed by ejecting ink onto a printing substrate.
[0039]
In addition, a test pattern for each nozzle may be formed by ejecting ink from all nozzles provided in the print head, and the test pattern for each nozzle may be included in the fifth region.
[0040]
In this way, it is possible to realize a test pattern area for performing determination on whether or not ink ejection has been normally performed for all the nozzles.
[0041]
It is also possible to realize a test pattern area printing method for printing the test pattern area by ejecting ink onto a substrate.
[0042]
=== Example of Overall Configuration of Apparatus ===
FIG. 1 is a block diagram showing a configuration of a printing system as an example of the present invention. This printing system includes a computer 90 and a color inkjet printer 20 as an example of a printing apparatus. The printing system including the color inkjet printer 20 and the computer 90 can also be called a “printing apparatus” in a broad sense. Although not shown, from the computer 90, the color inkjet printer 20, a display device such as a CRT 21 or a liquid crystal display device, an input device such as a keyboard or a mouse, a drive device such as a flexible drive device or a CD-ROM drive device, or the like. A computer system has been built.
[0043]
In the computer 90, an application program 95 operates under a predetermined operating system. A video driver 91 and a printer driver 96 are incorporated in the operating system, and print data PD to be transferred to the color inkjet printer 20 is output from the application program 95 via these drivers. The application program 95 that performs image retouching or the like performs desired processing on the image to be processed, and displays an image on the CRT 21 via the video driver 91.
[0044]
When the application program 95 issues a print command, the printer driver 96 of the computer 90 receives the image data from the application program 95 and converts it into print data PD to be supplied to the color inkjet printer 20. The printer driver 96 includes a resolution conversion module 97, a color conversion module 98, a halftone module 99, a rasterizer 100, a user interface display module 101, a UI printer interface module 102, and a color conversion lookup table LUT. And are provided.
[0045]
The resolution conversion module 97 plays a role of converting the resolution of the color image data formed by the application program 95 into the print resolution. The image data thus converted in resolution is still image information composed of three color components of RGB. The color conversion module 98 converts RGB image data into multi-gradation data of a plurality of ink colors that can be used by the color inkjet printer 20 for each pixel while referring to the color conversion lookup table LUT.
[0046]
The color-converted multi-gradation data has, for example, 256 gradation values. The halftone module 99 performs so-called halftone processing to generate halftone image data. The halftone image data is rearranged in the order of data to be transferred to the color inkjet printer 20 by the rasterizer 100, and is output as final print data PD. The print data PD includes raster data indicating the dot formation state during each main scan and data indicating the sub-scan feed amount.
[0047]
The user interface display module 101 has a function of displaying various user interface windows related to printing, and a function of receiving user input in these windows.
[0048]
The UI printer interface module 102 has a function of interfacing between a user interface (UI) and a color inkjet printer. Interpret the command instructed by the user through the user interface and send various commands COM to the color inkjet printer, or conversely interpret the command COM received from the color inkjet printer and perform various displays on the user interface . Further, it has a function of reading a test pattern print signal TPS relating to a test pattern, which will be described later, from the hard disk 92 and supplying it to the color inkjet printer 20.
[0049]
The printer driver 96 realizes a function of transmitting / receiving various commands COM, a function of supplying the print data PD and the test pattern print signal TPS to the color inkjet printer 20, and the like. A program for realizing the function of the printer driver 96 is supplied in a form recorded on a computer-readable recording medium. Such recording media include flexible disks, CD-ROMs, magneto-optical disks, IC cards, ROM cartridges, punch cards, printed matter on which codes such as bar codes are printed, computer internal storage devices (such as RAM and ROM). A variety of computer-readable media such as a memory) and an external storage device can be used. It is also possible to download such a computer program to the computer 90 via the Internet.
[0050]
FIG. 2 is a schematic perspective view illustrating an example of a main configuration of the color inkjet printer 20. This color inkjet printer 20 includes a paper stacker 22, a paper feed roller 24 driven by a step motor (not shown), a platen 26, a carriage 28, a carriage motor 30, and a traction belt 32 driven by the carriage motor 30. And a guide rail 34 for the carriage 28. In addition, a print head 36 having a large number of nozzles and a reflective optical sensor 29 described in detail later are mounted on the carriage 28.
[0051]
The printing paper P is taken up by the paper feed roller 24 from the paper stacker 22 and fed on the surface of the platen 26 in the sub-scanning direction. The carriage 28 is pulled by a pulling belt 32 driven by a carriage motor 30 and moves in the main scanning direction along the guide rail 34.
[0052]
The main scanning direction refers to both directions of reciprocation in which the carriage 28 moves along the guide rail 34, while the sub-scanning direction refers to only one direction in which the printing paper P is fed on the surface of the platen 26. The main scanning direction is perpendicular to the sub-scanning direction.
[0053]
The paper feeding roller 24 also performs a paper feeding operation for supplying the printing paper P to the color ink jet printer 20 and a paper discharging operation for discharging the printing paper P from the color ink jet printer 20.
[0054]
=== Configuration Example of Reflective Optical Sensor ===
FIG. 3 is a schematic diagram for explaining an example of the reflective optical sensor 29. The reflective optical sensor 29 is attached to the carriage 28, and includes a light emitting unit 38 made of, for example, a light emitting diode and a light receiving unit 40 made of, for example, a phototransistor. Light emitted from the light emitting unit 38, that is, incident light is reflected by the printing paper P, and the reflected light is received by the light receiving unit 40 and converted into an electrical signal. And the magnitude | size of an electrical signal is measured as an output value of the light receiving sensor according to the intensity of the received reflected light.
[0055]
In the above description, as shown in the drawing, the light emitting unit 38 and the light receiving unit 40 are integrated to form a device called the reflective optical sensor 29. However, like the light emitting device and the light receiving device, respectively. A separate device may be configured.
[0056]
In the above, in order to obtain the intensity of the received reflected light, the magnitude of the electric signal is measured after converting the reflected light into an electric signal. However, the present invention is not limited to this. It is only necessary to measure the output value of the light receiving sensor according to the intensity of the reflected light.
[0057]
=== Example of an electrical configuration of a color inkjet printer ===
FIG. 4 is a block diagram illustrating an example of an electrical configuration of the color inkjet printer 20. The color inkjet printer 20 includes a buffer memory 50 that receives a signal supplied from a computer 90, an image buffer 52 that stores print data, a system controller 54 that controls the overall operation of the color inkjet printer 20, and a main memory 56. And an EEPROM 58. The system controller 54 further includes a main scanning drive circuit 61 that drives the carriage motor 30, a sub-scanning drive circuit 62 that drives the paper feed motor 31, a head drive circuit 63 that drives the print head 36, and reflective optics. A light emitting unit 38 of the sensor 29 and a reflection type optical sensor control circuit 65 for controlling the light receiving unit 40 are connected. The reflection type optical sensor control circuit 65 includes an electric signal measurement unit 66 for measuring an electric signal converted from the reflected light received by the light receiving unit 40.
[0058]
The print data transferred from the computer 90 is temporarily stored in the buffer memory 50. In the color ink jet printer 20, the system controller 54 reads necessary information from the print data from the buffer memory 50, and based on this, the main scanning drive circuit 61, the sub-scanning drive circuit 62, and the head drive circuit 63 are read. Send a control signal.
[0059]
The image buffer 52 stores print data of a plurality of color components received by the buffer memory 50. The head drive circuit 63 reads the print data of each color component from the image buffer 52 in accordance with a control signal from the system controller 54 and drives the nozzle array of each color provided in the print head 36 in response to this.
[0060]
=== Example of print head nozzle arrangement ===
FIG. 5 is an explanatory diagram showing the nozzle arrangement on the lower surface of the print head 36. First, paying attention to FIG. 5A, the print head 36 has a black nozzle row and a color nozzle row respectively arranged on a straight line along the sub-scanning direction SS. In this specification, the “nozzle row” is also referred to as “nozzle group”.
[0061]
The black nozzle row (indicated by white circles) has 180 nozzles # 1 to # 180. These nozzles # 1 to # 180 are arranged at a constant nozzle pitch k · D along the sub-scanning direction. Here, D is the dot pitch in the sub-scanning direction SS, and k is an integer. The dot pitch D in the sub-scanning direction is equal to the pitch of the main scanning line (raster line). Hereinafter, the integer k representing the nozzle pitch k · D is simply referred to as “nozzle pitch k”. The unit of the nozzle pitch k is “dot”, which means the dot pitch in the sub-scanning direction.
[0062]
In the example of FIG. 5, the nozzle pitch k is 1 dot. However, the nozzle pitch k can be set to an arbitrary integer.
[0063]
The color nozzle array includes a yellow nozzle group Y (indicated by white triangles), a magenta nozzle group M (indicated by white squares), and a cyan nozzle group C (indicated by white rhombuses). In this specification, the nozzle group for chromatic ink is also referred to as a “chromatic nozzle group”. Each chromatic nozzle group has 60 nozzles # 1 to # 60. Further, the nozzle pitch of the chromatic nozzle group is the same as the nozzle pitch k of the black nozzle row. The nozzles of the chromatic color nozzle group are arranged at the same sub-scanning position as the nozzles of the black nozzle row.
[0064]
During printing, ink droplets are ejected from each nozzle while the print head 36 is moving in the main scanning direction together with the carriage 28. However, depending on the printing method, not all nozzles are always used, and only some nozzles may be used.
[0065]
Note that FIG. 5B will be described later.
[0066]
=== First Embodiment ===
Next, a first embodiment of the present invention will be described with reference to FIG. FIG. 6 is a flowchart for explaining the first embodiment.
[0067]
First, when the user senses an abnormality in missing dots, an instruction is given from the UI window to perform a missing dot inspection to determine whether or not dot formation has been performed normally (step S2). .
[0068]
FIG. 7 is a schematic diagram illustrating an example of a UI window for a user to instruct a missing dot inspection. A screen for instructing such inspection exists in the printer property utility, etc., and the user clicks a button corresponding to dot missing inspection (the square button shown in the upper left of the figure) with the mouse to perform dot missing inspection. Let it begin.
[0069]
A user's instruction for dot dropout inspection is received by the user interface display module 101 and sent to the UI printer interface module 102. The UI printer interface module 102 interprets the instructed command and transmits a command COM to the color inkjet printer 20. The color inkjet printer 20 receives the command COM by the buffer memory 50 and then transmits it to the system controller 54.
[0070]
Based on the command transmitted to the system controller 54, the color inkjet printer 20 feeds the printing paper by driving the paper feed motor 31 by the sub-scanning drive circuit 62 (step S4).
[0071]
Further, the color inkjet printer 20 uses the main scanning drive circuit 61, the sub-scanning drive circuit 62, and the head drive circuit 63 based on the command transmitted to the system controller 54, so that the carriage motor 30, the paper feed motor 31, and the print head 36. And a predetermined test pattern is printed on the fed printing paper (step S6).
[0072]
Here, an example of the test pattern will be described with reference to FIGS.
[0073]
FIG. 5B shows the print head 36 having a simplified black nozzle array for explaining the test pattern and the procedure for creating the test pattern. That is, this simplified black nozzle row is obtained by reducing the number of black nozzles, which is 180 in FIG. 5A, to 12.
[0074]
FIG. 8 is a diagram showing an example of the test pattern and a procedure for creating the test pattern.
[0075]
The test pattern is printed as follows by the print head 36 having the nozzle arrangement shown in FIG. First, out of the 12 black nozzles, ink is ejected from the nozzles indicated by # 1, # 5, and # 9 to form three dots arranged in the sub-scanning direction. This is repeated twice while moving the carriage in the main scanning direction. (FIG. 8 (a)). In the following description, the black nozzles denoted by # 1 to # 12 are simply referred to as No. 1 nozzle to No. 12 nozzle.
[0076]
Further, while moving the carriage in the main scanning direction, ink is ejected from the second nozzle, the sixth nozzle, and the tenth nozzle to form three dots arranged in the sub-scanning direction, and this is repeated twice. Next, the same operation is performed with the combination of No. 3, No. 7, and No. 11 nozzles, and the combination of No. 4, No. 8, No. 12 and No. 12 nozzles (FIG. 8B).
[0077]
Next, the above-described series of operations is repeated again while moving the carriage in the main scanning direction. In other words, the 24 dots shown in FIG. 8B are formed again while moving the carriage in the main scanning direction (FIG. 8C).
[0078]
Next, 1-dot paper feeding is performed, and the same procedure is repeated (FIG. 8D). Further, this procedure is repeated two more times (FIG. 8 (e)).
[0079]
Next, 9-dot paper feeding is performed, and the procedure from FIG. 8A to FIG. 8C is repeated (FIG. 8F). Further, by repeating the procedure from FIG. 8D to FIG. 8E, a test pattern for each nozzle is completed (FIG. 8G).
[0080]
As can be understood from FIG. 8G, 8 dots (2 × 4 dots) are formed for each of the 12 black nozzles. In the present specification, a pattern configured as one dot or a set of a plurality of dots for each nozzle is referred to as a “test pattern” for each nozzle.
[0081]
In FIG. 5B, the numbers 1 to 12 indicating the nozzles of the print head 36 correspond to the numbers 1 to 12 represented in white circles indicating the dots formed in FIG.
[0082]
Attention is now directed to FIG. FIG. 9 is an explanatory diagram schematically showing a plurality of completed test patterns shown in FIG.
[0083]
FIG. 9A schematically shows a test pattern for each nozzle. That is, the area indicated by the rectangle represents the test pattern for each nozzle, and the symbol indicated in the area, for example, TP1a, indicates the test pattern for the first nozzle. The symbol “a” is a symbol given to distinguish each test pattern because there are a plurality of test patterns for the first nozzle. In FIG. 9A, since there are four test patterns for each nozzle, the symbols include “b”, “c”, and “d” in addition to “a”.
[0084]
FIG. 9B is a diagram schematically showing FIG. 9A. In FIG. 9A, the twelve test patterns located in the upper left part are each formed by the first nozzle to the twelfth nozzle, and the same applies to the twelve test patterns located in the upper right part. It is. Further, the arrangement of the 12 test patterns located in the upper left part is the same as the arrangement of the 12 test patterns located in the upper right part. The same applies to the 12 test patterns located in the lower left and the 12 test patterns located in the lower right.
[0085]
That is, an area composed of 12 test patterns located at the upper left is a first area, an area composed of 12 test patterns located at the lower left is a second area, and 12 areas located at the upper right 9A is simplified as shown in FIG. 9B, assuming that the area composed of test patterns is the third area and the area composed of 12 test patterns located in the lower right is the fourth area. Furthermore, the arrangement of the test patterns included in each region is the same.
[0086]
In other words, a first area constituted by a predetermined test pattern arrangement, and a second area constituted by a test pattern arrangement similar to the first area at a position adjacent to the first area in the sub-scanning direction; A third region composed of a test pattern arrangement similar to that of the first region at a position adjacent to the first region in the main scanning direction; a second region adjacent to the second region in the main scanning direction; and a third region The fourth area constituted by the same test pattern arrangement as that of the first area is printed on the printing paper at a position adjacent to the sub-scanning direction.
[0087]
Then, irradiating the test pattern with light, receiving the reflected light, and comparing the light receiving sensor output value according to the intensity of the reflected light with a threshold value to determine whether or not the dot has been formed normally. However, the details of this case will be described later.
[0088]
Here, for the sake of convenience, the simplified nozzle arrangement of the print head 36 shown in FIG. 5B has been described as an example, but the same applies to the more complicated nozzle arrangement shown in FIG. It is possible to create a test pattern with this idea.
[0089]
In this example, one test pattern is formed by 8 dots, but the number of dots in one test pattern is completely arbitrary.
[0090]
Further, although the color nozzle row is omitted in FIG. 5B, the test pattern shown in FIG. Light can be applied to the test pattern to determine whether dot formation has been performed normally.
[0091]
Again, returning to the flowchart shown in FIG. After the printing of the test pattern is completed, the color inkjet printer 20 drives the paper feed motor 31 by the sub-scanning drive circuit 62 based on the command transmitted from the computer 90 to the system controller 54, and the like. The paper is discharged (step S8).
[0092]
Next, in order to display a message prompting the user to set again the printing paper on which the test pattern is printed, the system controller 54 transmits a command to that effect to the buffer memory 50, and the buffer memory 50 (Command COM) is transmitted to the computer 90. The computer 90 receives the command by the UI printer interface module 102, and causes the user interface display module 101 to display a message for prompting the user to set again the printing paper on which the test pattern is printed (step S10).
[0093]
The user who sees the message prints the test pattern and sets the discharged printing paper on the color inkjet printer again (step S12). This printing paper is fed by the same method as described above (step S14).
[0094]
Next, light is applied to the test pattern on the printing paper, and the intensity of the reflected light is measured (step S16), thereby determining whether or not the dots have been formed normally (step S24).
[0095]
This procedure will be described below with reference to FIG. FIG. 10 is an explanatory diagram for explaining a procedure for determining whether or not dot formation has been normally performed based on the test pattern shown in FIG.
[0096]
After the printing paper is fed, the color inkjet printer 20 emits light toward the printing paper by controlling the light emitting unit 38 by the reflection type optical sensor control circuit 65 based on a command from the system controller 54. The carriage 28 is moved in the main scanning direction by driving the carriage motor 30 by the main scanning drive circuit 61 and the paper feed motor 31 is driven by the sub-scanning driving circuit 62. Feed.
[0097]
Then, for example, at the timing when the central portion of the irradiation area of the light emitted from the reflective optical sensor 29 provided on the carriage 28 coincides with the central portion of each test pattern, the reflected light by the test pattern of the emitted light is emitted. Light is received by the light receiving unit 40. The relative position of the reflective optical sensor with respect to the printing paper required for determining whether the center of the light irradiation area matches the center of each test pattern is not shown. Calculation is performed based on the output of the encoder.
[0098]
In this embodiment, among the plurality of test patterns shown in FIG. 10, only a test pattern surrounded by a thick line is set as a target test pattern for dot dropout inspection. At this time, it is not always necessary to perform dot dropout inspection for all 24 test patterns surrounded by a thick line. For example, 12 test patterns (symbols TP7a, TP7a, Even if it is limited to TP11a, TP3b, TP8a, TP12a, TP4b, TP9c, TP1d, TP5d, TP10c, TP2d, TP6d), all test patterns corresponding to the 1st to 12th nozzles are included. That ’s enough. Also, all test patterns corresponding to the 1st to 12th nozzles are included, such as selecting test patterns indicated by the symbols TP6a, TP10a, and TP2b instead of the test patterns indicated by the symbols TP10c, TP2d, and TP6d. There are a plurality of ways of selecting test patterns for doing so, and any selection method may be adopted as a method of selecting a test pattern to be subjected to dot dropout inspection. Further, as a matter of course, the dot dropout inspection may be performed for all of the 24 test patterns surrounded by thick lines in FIG.
[0099]
The test pattern surrounded by the bold line is a test pattern in which other test patterns are printed on the front side and the rear side in the main scanning direction and the sub-scanning direction when dots are formed normally. is there.
[0100]
For example, the test pattern indicated by the symbol TP6a has TP3a and TP7a on the front side in the main scanning direction, TP5a and TP9a on the rear side, TP10a on the front side in the sub-scanning direction, and TP2a on the rear side. Since the test pattern shown is printed, it is a target test pattern for dot dropout inspection.
[0101]
On the other hand, the test pattern indicated by symbol TP1a is printed with a test pattern indicated by TP2a on the front side in the main scanning direction and TP5a on the front side in the sub-scanning direction. Since a test pattern is not printed on the rear side in the sub-scanning direction, it is not a target test pattern for dot dropout inspection. The test pattern indicated by symbol TP3a is also printed with TP4a on the front side in the main scanning direction, TP2a and TP6a on the rear side, and TP7a on the front side in the sub-scanning direction. However, since a test pattern is not printed on the rear side in the sub-scanning direction, it is not a target test pattern for dot dropout inspection.
[0102]
The light reflected by the test pattern of the emitted light is received by the light receiving unit 40 and converted into an electrical signal by the reflective optical sensor control circuit 65.
[0103]
Then, as the output value of the light receiving sensor corresponding to the intensity of the received reflected light, the magnitude of the electric signal is measured by the electric signal measuring unit 66 provided in the reflective optical sensor control circuit 65.
[0104]
The measurement result is sent to the UI printer interface module 102 provided in the printer driver 96 via the system controller 54 and the buffer memory 50. In the UI printer interface module 102, the measurement result is compared with a preset threshold value, and it is determined whether or not dot formation has been performed normally. Then, the result of the determination is sent to the user interface display module 101, and the result of the missing dot inspection is displayed in the UI interface window (step S24). The determination may be performed in the color inkjet printer 20 such as the system controller 54.
[0105]
In parallel with step S24, the printing paper on which the test pattern is printed is discharged (step S18). Note that when an abnormality in dot formation is recognized, the print head may be cleaned, or a dot dropout inspection may be performed once again for reconfirmation.
[0106]
Thus, among the test patterns formed for each nozzle, a test pattern in which other test patterns are printed on the front side and the rear side in the main scanning direction and the sub-scanning direction when dot formation is performed normally, By determining whether or not the dot formation has been normally performed only for the target, the determination can be performed with high accuracy without necessarily providing a separate threshold for each test pattern.
[0107]
A more detailed description will be added with reference to FIG. As described in the background art section, in order to realize a reduction in cost, it is desirable to use a reflective optical sensor including a light emitting unit having an irradiation region extending over several test patterns.
[0108]
However, when the determination is performed by the reflective optical sensor, in each test pattern indicated by the symbols TP1a, TP1b, TP1c, and TP1d in FIG. 10, regardless of whether the dot formation is normal or not, Since the light receiving sensor output value differs according to the intensity of the reflected light, it is necessary to provide a separate threshold value for each test pattern in order to make an accurate determination.
[0109]
In other words, the test pattern indicated by the symbol TP1d is completely filled with other test patterns, while the test patterns indicated by the symbols TP1a, TP1b, and TP1c are adjacent to the so-called paper background. A portion of paper is included in the irradiation area. Accordingly, since the output value of the light receiving sensor differs for each test pattern, there is a trouble that the threshold value must be set in detail in consideration of this point.
[0110]
Therefore, only the test pattern whose surroundings are filled with other test patterns, such as the test pattern indicated by the symbol TP1d, that is, only the test pattern surrounded by the thick line in FIG. Thus, the determination can be performed with high accuracy without providing a separate threshold for each test pattern.
[0111]
In the present embodiment, a first area configured by a predetermined test pattern array, and a test pattern array similar to the first area are arranged at positions adjacent to the first area in the sub-scanning direction. The second region, the first region adjacent to the first region in the main scanning direction, the third region constituted by the same test pattern arrangement as the first region, the second region adjacent to the main scanning direction, and The fourth area constituted by the same test pattern arrangement as the first area at a position adjacent to the third area in the sub-scanning direction is printed on the printing paper, and among the test patterns included in each area, Although only test patterns in which other test patterns are printed on the front side and rear side in the main scanning direction and the sub-scanning direction when dots are formed normally are printed on the printing paper. For the area, it is not limited to the above-mentioned regions. For example, a region that is not subject to inspection may be provided so as to surround the test pattern that is subject to inspection by ejecting ink from a single nozzle.
[0112]
However, as understood from FIG. 9B, the first, second, third, and fourth areas were printed, and the dots were formed normally among the test patterns included in each area. In this case, the examples shown in the first embodiment in which only test patterns on which other test patterns are printed on the front side and the rear side in the main scanning direction and the sub-scanning direction are the inspection targets are the first, second, If the test pattern arrangement of the third and fourth areas is the same, for example, near the center of all four areas (ie, near the lower right part of the first area, near the upper right part of the second area, near the lower left part of the third area) Test pattern corresponding to all nozzles while excluding test patterns adjacent to paper so as to be inspected by making test patterns located near the upper left of the fourth area) Easy to inspect More desirable in that it is Rukoto.
[0113]
In addition, the test pattern arrangement in each area is arbitrary, and it is not always necessary that each area includes a test pattern based on all nozzles of the print head, and a plurality of test patterns based on the same nozzle are included in each area. It may be included.
[0114]
=== Second Embodiment ===
Next, a second embodiment of the present invention will be described.
[0115]
The procedure for determining the presence or absence of missing dots in the present embodiment is the same as that already described in the first embodiment based on FIG. 6, but the test pattern printed on the printing paper in step S6. And the step of measuring the intensity of reflected light by applying light to the test pattern performed in step S16 is slightly different from that described in the first embodiment.
[0116]
First, an example of the test pattern will be described with reference to FIGS.
[0117]
FIG. 5B shows the print head 36 having a simplified black nozzle array in order to explain the test pattern and the test pattern creation procedure, as described above. FIG. 11 is a diagram illustrating an example of the test pattern and a procedure for creating the test pattern.
[0118]
The test pattern is printed as follows by the print head 36 having the nozzle arrangement shown in FIG.
[0119]
First, of the 12 black nozzles, ink is ejected from the 9th nozzle to form one dot. This is repeated twice while moving the carriage in the main scanning direction. Further, while moving the carriage in the main scanning direction, ink is ejected from the 10th nozzle to form one dot, and this is repeated twice. Next, the same operation is performed for the 11th and 12th nozzles. Next, the above-described series of operations is repeated again while moving the carriage in the main scanning direction. Next, 1-dot paper feeding is performed, and the same procedure is repeated (FIG. 11A).
[0120]
5B, the numbers 1 to 12 indicating the nozzles of the print head 36 correspond to the numbers 1 to 12 indicating the dots formed in FIG. It is the same as the form. Further, in FIG. 11, numbers surrounded by white circles and numbers not surrounded by white circles are shown, but the former shows dots formed by actually ejecting ink, The latter is a dot that is not actually formed, but is shown in FIG. 11 for easy understanding of the drawing.
[0121]
Next, five-dot paper feed is performed, and among the 12 black nozzles, ink is ejected from the first nozzle, the fifth nozzle, and the ninth nozzle to form three dots arranged in the sub-scanning direction. This is repeated twice while moving the carriage in the main scanning direction. Further, while moving the carriage in the main scanning direction, ink is ejected from the second nozzle, the sixth nozzle, and the tenth nozzle to form three dots arranged in the sub-scanning direction, and this is repeated twice. Next, the same operation is performed with a combination of No. 3, No. 7, and No. 11 nozzles, and a combination of No. 4, No. 8, No. 12 and No. 12 nozzles. Next, the above series of operations is repeated again while moving the carriage further in the main scanning direction (FIG. 11B). Next, 1-dot paper feeding is performed, and the same procedure is repeated (FIG. 11C).
[0122]
Next, a 5-dot paper feed is performed, and ink is ejected from the 1st nozzle and the 5th nozzle among the 12 black nozzles to form two dots arranged in the sub-scanning direction. This is repeated twice while moving the carriage in the main scanning direction. Further, while moving the carriage in the main scanning direction, ink is ejected from the second and sixth nozzles to form two dots arranged in the sub-scanning direction, and this is repeated twice. Next, the same operation is performed with the combination of No. 3 nozzle and No. 7 nozzle, and the combination of No. 4 nozzle and No. 8 nozzle. Next, the above series of operations is repeated again while moving the carriage further in the main scanning direction (FIG. 11D).
[0123]
Next, 1-dot paper feed is performed, and the same procedure is repeated to complete a test pattern for each nozzle (FIG. 11E).
As can be understood from FIG. 11E, 4 dots (2 × 2 dots) are formed for each of the 12 black nozzles.
[0124]
Attention is now directed to FIG. FIG. 12 is an explanatory diagram schematically showing a plurality of completed test patterns shown in FIG. FIG. 12A schematically shows a test pattern for each nozzle. That is, the area indicated by the rectangle represents the test pattern for each nozzle, and the symbol indicated in the area, for example, TP1a, indicates the test pattern for the first nozzle. The symbol “a” is a symbol given to distinguish each test pattern because there are a plurality of test patterns for the first nozzle. In FIG. 12A, since there are four test patterns for each nozzle, the symbols include “b”, “c”, and “d” in addition to “a”.
[0125]
FIG. 12B is a diagram schematically showing FIG. 12A. A region composed of twelve test patterns indicated by symbols TP1a, TP2a, TP3a, TP4a, TP5a, TP6a, TP7a, TP8a, TP9a, TP10a, TP11a, and TP12a is a fifth region, and symbols TP9b, TP10b, TP11b, and TP12b A region composed of four test patterns indicated by the sixth region, and a region constituted by eight test patterns indicated by symbols TP1b, TP2b, TP3b, TP4b, TP5b, TP6b, TP7b, and TP8b. The area composed of 12 test patterns indicated by the area, symbols TP1c, TP2c, TP3c, TP4c, TP5c, TP6c, TP7c, TP8c, TP9c, TP10c, TP11c, TP12c is the eighth area, symbols TP9d, TP10d, TP11d , TP1 An area composed of four test patterns indicated by d is a ninth area, and an area constituted by eight test patterns indicated by symbols TP1d, TP2d, TP3d, TP4d, TP5d, TP6d, TP7d, and TP8d Assuming that there are ten regions, FIG. 12A can be simplified as shown in FIG.
[0126]
Furthermore, the arrangement of the test pattern of the upstream area and the sixth area in the sub-scanning direction of the fifth area is the same, and the arrangement of the test pattern of the area excluding the upstream part of the fifth area and the test pattern of the seventh area is The same. The same applies to the eighth, ninth, and tenth regions.
[0127]
In other words, a fifth area configured by a predetermined test pattern arrangement and a test pattern arrangement similar to the upstream area of the fifth area in the sub-scanning direction have a downstream area in the sub-scanning direction of the fifth area. A sixth region configured to overlap, and a fifth region configured to overlap the region excluding the downstream portion of the fifth region having the same test pattern arrangement as the region excluding the upstream portion of the fifth region. Seven areas, an eighth area composed of test patterns similar to the fifth area at positions adjacent to the fifth area in the main scanning direction, and a test pattern similar to the upstream portion of the eighth area in the sub-scanning direction A ninth region configured to overlap the downstream portion of the eighth region in the sub-scanning direction, and an eighth test region having the same test pattern as the region excluding the upstream portion of the eighth region. Area A tenth region configured to overlap the serial excluding the downstream partial region, and that are printed on the printing paper.
[0128]
Then, irradiating the test pattern with light, receiving the reflected light, and comparing the light receiving sensor output value according to the intensity of the reflected light with a threshold value to determine whether or not the dot has been formed normally. However, the details of this case will be described later.
[0129]
Here, for the sake of convenience, the simplified nozzle arrangement of the print head 36 shown in FIG. 5B has been described as an example, but the same applies to the more complicated nozzle arrangement shown in FIG. Test patterns can be created with the idea.
[0130]
In this example, one test pattern is formed by 4 dots, but the number of dots of one test pattern is completely arbitrary.
[0131]
Further, although the color nozzle row is omitted in FIG. 5B, the test pattern shown in FIG. 11E is printed on the printing paper according to the procedure described above for the black nozzle, Light can be applied to the test pattern to determine whether dot formation has been performed normally.
[0132]
Next, the light is applied to the test pattern on the printing paper and the intensity of the reflected light is measured (step S16), thereby determining whether or not the dot has been formed normally (step S24). This will be described below with reference to FIG. FIG. 13 is an explanatory diagram for explaining a procedure for determining whether or not dot formation has been normally performed based on the test pattern shown in FIG.
[0133]
After the printing paper is fed, the color inkjet printer 20 moves the carriage 28 in the main scanning direction while emitting light toward the printing paper, and the first point is that the printing paper is fed. This is the same as the embodiment. For example, the first point is that the light receiving unit 40 receives the reflected light at the timing when the center of the irradiation area of the light emitted from the reflective optical sensor 29 coincides with the center of each test pattern. This is the same as the embodiment.
[0134]
Further, among the plurality of test patterns shown in FIG. 13, only the test pattern surrounded by a thick line is set as a target test pattern for dot dropout inspection. At this time, it is not always necessary to perform dot dropout inspection for all 24 test patterns surrounded by bold lines. For example, 12 test patterns (symbols TP11b, TP11b, Even if it is limited to TP12b, TP7a, TP8a, TP3b, TP4b, TP5c, TP6c, TP1d, TP2d, TP9c, TP10c), all the test patterns corresponding to the 1st to 12th nozzles are included. That ’s enough. Also, all test patterns corresponding to the 1st nozzle to the 12th nozzle are included, such as selecting a test pattern indicated by the symbols TP11d, TP7c, TP3d instead of the test patterns indicated by the symbols TP11b, TP7a, TP3b. There are a plurality of ways of selecting test patterns for doing so, and any selection method may be adopted as a method of selecting a test pattern to be subjected to dot dropout inspection. Further, as a matter of course, the dot dropout inspection may be performed for all 24 test patterns surrounded by a thick line in FIG.
[0135]
As in the first embodiment, the test pattern surrounded by a thick line is a pattern in which other test patterns are arranged on the front side and the rear side in the main scanning direction and the sub-scanning direction when dots are formed normally. Is a test pattern to be printed.
[0136]
Then, the reflected light by the test pattern of the emitted light is received by the light receiving unit 40, converted into an electrical signal by the reflective optical sensor control circuit 65, and the output value of the light receiving sensor according to the intensity of the received reflected light. As described above, the magnitude of the electric signal is measured by the electric signal measuring unit 66 provided in the reflective optical sensor control circuit 65. The subsequent procedure is the same as that of the first embodiment.
[0137]
In this way, the fifth, sixth, seventh, eighth, ninth, and tenth areas were printed on the printing paper, and the dots were formed normally among the test patterns included in these areas. In this case, if the above determination is performed only for test patterns in which other test patterns are printed on the front side and the rear side in the main scanning direction and the sub-scanning direction, the entire area of the test pattern to be inspected is further reduced. Therefore, there is a merit that the time for inspecting the presence or absence of missing dots becomes shorter.
[0138]
That is, as understood from FIG. 12B, the fifth, sixth, seventh, eighth, ninth, and tenth areas are printed, and dots are formed among the test patterns included in each area. The example shown in the second embodiment in which only test patterns on which other test patterns are printed on the front side and the rear side in the main scanning direction and the sub-scanning direction when the inspection is normally performed For example, near the center of all six areas (ie, near the right center of the fifth area, near the lower right part of the sixth area, near the upper right part of the seventh area, near the left center of the eighth area, near the lower left part of the ninth area) Test pattern corresponding to all nozzles while excluding the test pattern adjacent to the so-called paper surface by subjecting the test pattern located near the upper left of the tenth area) Make it easy to inspect More desirable in that it can be. Furthermore, in the first embodiment, each region is arranged so as not to overlap with each other, whereas in the present embodiment, the fifth region and the sixth region, the fifth region and the seventh region, Since the 8th and 9th areas and the 8th and 10th areas are placed one on top of the other, the test corresponding to all nozzles while excluding test patterns adjacent to the so-called paper background There is an advantage that the area for inspecting the pattern is narrowed, and the time for inspecting the presence or absence of missing dots is shortened.
[0139]
Note that the test pattern arrangement in each area is not limited to the example shown in the embodiment, and it is not always necessary that each area includes a test pattern of all nozzles of the print head. A plurality of test patterns by the same nozzle may be included in each region.
[0140]
Further, as a matter common to the first and second embodiments, each test pattern has two or more dots in the sub-scanning direction (4 dots in the first embodiment, in the second embodiment). 2 dots) is printed, but this may be 1 dot.
[0141]
However, when each test pattern is printed with two or more dots formed in the sub-scanning direction, the density of the test pattern is higher when dots are formed normally. The difference between the output value of the light receiving sensor and the output value of the light receiving sensor when it is not normally performed becomes larger, and therefore it is possible to accurately determine the presence or absence of missing dots. In this respect, it is desirable to print each test pattern by forming two or more dots in the sub-scanning direction.
[0142]
=== Modification ===
As described above, the printing apparatus and the like according to the present invention have been described based on one embodiment. However, the above-described embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. Absent. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.
[0143]
Moreover, although the printing paper has been described as an example of the printing material, a film, a cloth, a thin metal plate, or the like may be used as the printing material.
[0144]
Further, a computer main body, a display device connected to the computer main body, a printer according to the above-described embodiment connected to the computer main body, an input device such as a mouse and a keyboard provided as necessary, a flexible disk drive A computer system having a device and a CD-ROM drive device can also be realized, and the computer system realized in this way is an overall system superior to the conventional system.
[0145]
The printer according to the above-described embodiment may have a part of functions or mechanisms respectively included in the computer main body, the display device, the input device, the flexible disk drive device, and the CD-ROM drive device. For example, the printer includes an image processing unit that performs image processing, a display unit that performs various displays, and a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. Also good.
[0146]
In the above embodiment, a color ink jet printer has been described. However, the present invention can be applied to a monochrome ink jet printer, and can also be applied to printers other than the ink jet system. The present invention is generally applicable to a printing apparatus that prints on a printing medium, and can also be applied to, for example, a facsimile machine and a copier. However, in a so-called ink jet type printing apparatus that performs printing by discharging ink from the print head, a high image quality of the printing result is particularly required, so that the merit of the above-described means is further increased.
[0147]
In the above description, each test pattern printed for each dot forming unit is printed in the same color, but may be printed in a different color. For example, some of the 12 test patterns included in the first area in the first embodiment may be printed by a yellow nozzle, a magenta nozzle, a cyan nozzle, or the like.
[0148]
However, if the colors differ for each test pattern, the density of each test pattern becomes non-uniform.Therefore, a separate threshold value is set for each test pattern in order to accurately determine whether or not dots are formed normally. Since there is a possibility that a problem arises that it is necessary to provide the test patterns, it is preferable to print the test patterns printed for each dot forming unit in the same color.
[0149]
In the above, the color inkjet printer 20 moves the carriage 28 in the main scanning direction while emitting light toward the printing paper, and feeds the printing paper, and the light emitted from the reflective optical sensor 29. Although the reflected light is received by the light receiving unit 40 at the timing when the center of the irradiation region coincides with the center of each test pattern, the center of the irradiation region of the light emitted from the reflective optical sensor 29 However, light may be emitted to the printing paper at a timing that coincides with the center of each test pattern. While the light is emitted toward the printing paper, the light receiving unit 40 always receives the reflected light, and the central part of the irradiation area of the light emitted from the reflective optical sensor 29 is the central part of each test pattern. It is possible to use only the data of the timing that matches In addition, when it is not necessary to specify the nozzles where dot formation was not normal, the presence / absence of missing dots is determined not only from the timing data matching the center of each test pattern but also from all data. It is good to do.
[0150]
In the above description, the dot dropout inspection is performed according to the user's instruction, but may be automatically performed without the user's instruction. Further, the inspection may be performed before the printing apparatus reaches the user's hand, for example, at the time of shipment.
[0151]
In the above, the test pattern is printed on the printing paper (step S6), the printing paper is discharged (step S8), and the printing paper is set again on the color inkjet printer by the user (step S12). The printing paper is fed (step S14), and light is applied to the test pattern of the printing paper and the intensity of the reflected light is measured (step S16). The test pattern is printed and the intensity of the reflected light is measured. It is also possible to omit steps S8, S12, and S14 by continuously performing the measurement.
[0152]
【The invention's effect】
According to the present invention, a printing apparatus, a dot formation determination method, a computer program, a recording medium, a computer system, a test pattern area, and a test pattern area printing method that accurately determine whether or not dot formation has been normally performed. Can be realized.
[0153]
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a printing system as an example of the present invention.
FIG. 2 is a schematic perspective view illustrating an example of a main configuration of the color inkjet printer 20;
FIG. 3 is a schematic diagram for explaining an example of a reflective optical sensor 29;
4 is a block diagram illustrating an example of an electrical configuration of the color inkjet printer 20. FIG.
FIG. 5 is an explanatory diagram showing a nozzle arrangement on the lower surface of the print head.
FIG. 6 is a flowchart for explaining the first embodiment;
FIG. 7 is a schematic diagram illustrating an example of a UI window for a user to instruct dot drop inspection.
FIG. 8 is a diagram illustrating an example of a test pattern and a procedure for creating the test pattern.
FIG. 9 is an explanatory view schematically showing a plurality of completed test patterns shown in FIG. 8 (g).
FIG. 10 is an explanatory diagram for explaining a procedure for determining whether or not dot formation has been performed normally based on the test pattern shown in FIG.
FIG. 11 is a diagram showing an example of the test pattern and a procedure for creating the test pattern.
12 is an explanatory view schematically showing a plurality of completed test patterns shown in FIG. 11 (e).
FIG. 13 is an explanatory diagram for explaining a procedure for determining whether or not dot formation has been normally performed based on the test pattern shown in FIG.
FIG. 14 is a conceptual diagram showing a test pattern formed for each nozzle and a light irradiation area by a light emitting device.
[Explanation of symbols]
20 ... Color inkjet printer
21 ... CRT
22: Paper stacker
24 ... paper feed roller
26 ... Platen
28 ... Carriage
29 ... Reflective optical sensor
30 ... Carriage motor
31 ... Paper feed motor
32 ... Traction belt
34 ... Guide rail
36... Print head
38 ... Light emitting part
40: Light receiving part
50 ... Buffer memory
52 ... Image buffer
54 ... System controller
56 ... Main memory
58 ・ ・ ・ EEPROM
61 ... Main scanning drive circuit
62... Sub-scanning drive circuit
63... Head drive circuit
65... Reflective optical sensor control circuit
66 ... Electric signal measuring unit
90 ... Computer
91 ... Video driver
92 ... Hard disk
95 ... Application program
96 ... Printer driver
97 ... Resolution conversion module
98 ... color conversion module
99 ・ ・ ・ Halftone module
100 ... Rasterizer
101 ... User interface display module
102: UI printer interface module

Claims (7)

A print head having a plurality of dot forming means for forming dots, forming a dot on a substrate to be printed for each of the dot forming means, printing a test pattern, The light receiving sensor emits light by a light emitting device having an irradiation area extending over the test pattern, and receives light reflected by the printing body of the emitted light by a light receiving sensor, and the light receiving sensor according to the intensity of the received reflected light A printing apparatus that determines whether or not the dot formation by each dot forming unit is normally performed based on the output value of
The printing apparatus prints a test pattern for each dot forming unit in a sub-scanning direction, which is a direction in which the printing medium is fed, and a main scanning direction, which is a direction intersecting the sub-scanning direction,
The test pattern printed adjacent to the main scanning direction of the test pattern printed by one of the dot forming means is a test pattern printed by another dot forming means, and among the test patterns, A test pattern in which other test patterns are printed on the front side and the back side in the main scanning direction, the sub-scanning direction, and the oblique direction between the main scanning direction and the sub-scanning direction when the formation is performed normally. The printing apparatus according to claim 1, wherein the determination is performed only for a test pattern in which the other test pattern is printed without the ground of the printing body being adjacent to the entire periphery of the pattern. 2. The printing apparatus according to claim 1, wherein a test pattern similar to the first area is formed at a position adjacent to the first area in the sub-scanning direction and the first area constituted by the predetermined test pattern arrangement. A second region configured by an array, a third region configured by an array of test patterns similar to the first region at a position adjacent to the first region in the main scanning direction, the second region and the main region A fourth area constituted by an array of test patterns similar to the first area at a position adjacent to the third direction and adjacent to the third area in the sub-scanning direction is provided with dots on the substrate. Forming and printing,
Among the test patterns of the first region to the fourth region, the front side in the main scanning direction and the sub-scanning direction and the diagonal direction between the main scanning direction and the sub-scanning direction when the dot formation is performed normally, and Only a test pattern in which another test pattern is printed on the rear side and the other test pattern is printed without the ground of the substrate being adjacent to the entire periphery of the test pattern. A printing apparatus that performs the determination as an object. The printing apparatus according to claim 1, further comprising: a fifth area configured by a predetermined test pattern arrangement; and a test pattern arrangement similar to an upstream portion of the fifth area in the sub-scanning direction. A sixth region configured to overlap a downstream portion in the sub-scanning direction of the five regions, and an array of test patterns similar to the region excluding the upstream portion of the fifth region, and the fifth region A seventh region configured to overlap the region excluding the downstream portion, and an eighth region configured by an arrangement of test patterns similar to the fifth region at a position adjacent to the fifth region in the main scanning direction; A ninth region having the same test pattern arrangement as the upstream portion of the eighth region in the sub-scanning direction and overlapping the downstream portion of the eighth region in the sub-scanning direction; and Before The tenth area having the same test pattern arrangement as the area excluding the upstream part and overlapping the area excluding the downstream part of the eighth area is formed with dots on the substrate. Print
Of the test patterns of the fifth to tenth regions, when the dots are formed normally, the front side in the main scanning direction and the sub-scanning direction and the diagonal direction between the main scanning direction and the sub-scanning direction, and Only a test pattern in which another test pattern is printed on the rear side and the other test pattern is printed without the ground of the substrate being adjacent to the entire periphery of the test pattern. A printing apparatus that performs the determination as an object.   4. The printing apparatus according to claim 1, wherein two or more dots are formed in a sub-scanning direction and the test pattern is printed on a printing medium. 5.   5. The printing apparatus according to claim 1, wherein a test pattern printed for each dot forming unit is printed in the same color. 6.   6. The printing apparatus according to claim 1, wherein the dot forming means is a nozzle for discharging ink to form dots. A step of printing a test pattern by forming dots on a printing medium for each of a plurality of dot forming means for forming dots provided on a print head, and irradiation over several test patterns toward the test pattern A step of emitting light by a light emitting device having a region, a step of receiving reflected light of the emitted light by the printing medium by a light receiving sensor, and an output of the light receiving sensor according to the intensity of the received reflected light A step of determining whether or not the dot formation by each dot forming means has been normally performed based on the value, and a dot formation determination method comprising:
The printing step prints a test pattern for each dot forming unit in a sub-scanning direction, which is a direction in which the printing medium is fed, and a main scanning direction, which is a direction intersecting the sub-scanning direction. The test pattern printed adjacent to the main scanning direction of the test pattern printed by one of the dot forming means is a test pattern printed by another dot forming means, and the step of performing the determination includes Among the test patterns, when the dots are formed normally, other test patterns are printed on the front side and the back side in the main scanning direction, the sub-scanning direction, and the diagonal direction between the main scanning direction and the sub-scanning direction. A test pattern in which the ground of the substrate to be printed is not adjacent to the periphery of the test pattern and the other test pattern is printed. The dot formation determination method, wherein the determination is performed only on the target.

Images