Patent Grant
11305551
The present disclosure relates to a control device for a printing execution unit including a printing head having a plurality of nozzles and a movement unit configured to move a printing medium relative to the printing head.
Related art discloses a printing apparatus configured to cause a printing head to scan so as to perform printing in a band unit. The printing apparatus is configured to execute an overlap printing of printing dot rows in a main scanning direction by using two or three nozzles so as to suppress banding. At this time, when an edge forming pixel of a character region is included in a dot row to be printed using the three nozzles, the printing apparatus prints the dot row by using the two nozzles.
However, according to the above technology, it may not be possible to sufficiently suppress a defect that a character is to be thickened due to the printing of the character using the two or more nozzles during the overlap printing.
An aspect of the present disclosure provides a technology capable of suppressing a character from being thickened in a print image.
According to an aspect of the disclosure, there is provided a control device for a printing execution unit including: a printing head including a plurality of nozzles configured to discharge ink; a head drive unit configured to cause the printing head to discharge the ink and to form dots on a printing medium; and a movement unit configured to move the printing medium relative to the printing head in a moving direction, the control device including: a controller configured to perform: acquiring target image data; specifying a character region indicative of a character in a print image based on the target image data, and a non-character object region indicative of an object different from the character in the print image; and causing the printing execution unit to print the print image by using the target image data, the print image being printed by alternately executing, for a plurality of times, (i) a partial printing in which dots are formed by the printing head and (ii) moving of the printing medium by the movement unit, and the plurality of times of the partial printings including a first partial printing and a second partial printing, wherein, in a case where a first condition including a condition that the non-character object region is located at an upstream end, in the moving direction, of a partial region which is configured to be printed by the first partial printing is met, the printing execution unit is caused to print the print image by: executing the first partial printing; moving the printing medium by a first movement amount after the first partial printing has been executed; and executing the second partial printing after the printing medium has been moved by the first movement amount, wherein dots are formed in a first overlap region by both the first partial printing and the second partial printing, the first overlap region including the upstream end of the partial region, wherein, in a case where a second condition including a condition that the character region is located at the upstream end of the partial region is met, the printing execution unit is caused to print the print image by: executing the first partial printing; moving the printing medium by a second movement amount greater than the first movement amount after the first partial printing has been executed; and executing the second partial printing after the printing medium has been moved by the second movement amount, wherein dots are formed in a second overlap region by both the first partial printing and the second partial printing, the second overlap region including the upstream end of the partial region, and wherein a length of the second overlap region in the moving direction is shorter than a length of the first overlap region in the moving direction.
According to the above configuration, in a case where the second condition including the condition that the character region is located at the upstream end of the partial region is met, the length of the second overlap region in which the dots are formed by both the first partial printing and the second partial printing becomes shorter than the length of the first overlap region. As a result, it is possible to suppress the character from being thickened. Also, in this case, since the printing medium is moved by the second movement amount greater than the first movement amount after the first partial printing has been executed, it is possible to increase the printing speed.
According to another aspect of the disclosure, there is provided a control device for a printing execution unit including: a printing head including a plurality of nozzles configured to discharge ink; a head drive unit configured to cause the printing head to discharge the ink and to form dots on a printing medium; and a movement unit configured to move the printing medium relative to the printing head in a moving direction, the control device including: a controller configured to perform: acquiring target image data; specifying a character region indicative of a character in a print image based on the target image data, and a non-character object region indicative of an object different from the character in the print image; and causing the printing execution unit to print the print image by using the target image data, the print image being printed by alternately executing, for a plurality of times, (i) a partial printing in which dots are formed by the printing head and (ii) moving of the printing medium by the movement unit, and the plurality of times of the partial printings including a first partial printing and a second partial printing, wherein, in a case where a first condition including a condition that the non-character object region is located at an upstream end, in the moving direction, of a partial region which is configured to be printed by the first partial printing is met, the printing execution unit is caused to print the print image by: executing the first partial printing; moving the printing medium by a first movement amount after the first partial printing has been executed; and executing the second partial printing after the printing medium has been moved by the first movement amount, wherein dots are formed in a first overlap region by both the first partial printing and the second partial printing, the first overlap region including the upstream end of the partial region, wherein, in a case where a second condition including a condition that the character region is located at the upstream end of the partial region is met, the printing execution unit is caused to print the print image by: executing the first partial printing; moving the printing medium by a second movement amount greater than the first movement amount after the first partial printing has been executed; and executing the second partial printing after the printing medium has been moved by the second movement amount, wherein the dots are formed in the partial region by the first partial printing and the dots are not formed in the partial region by the second partial printing.
According to the above configuration, in a case where the second condition including the condition that the character region is located at the upstream end of the partial region is met, the dots are not formed in the partial region during the second partial printing. As a result, it is possible to suppress the character from being thickened. Also, in this case, since the printing medium is moved by the second movement amount greater than the first movement amount after the first partial printing has been executed, it is possible to increase the printing speed.
In the meantime, the technology of the present disclosure can be implemented in a variety of forms, such as a printing apparatus, a control method of the printing execution unit, a printing method, a storage medium having a computer program for implementing functions of the apparatus and method recorded therein, and the like.
A-1: Configuration of Printer 200
Hereinafter, an illustrative embodiment will be described.
A printer 200 includes a printing mechanism 100, a CPU 210 as a control device for the printing mechanism 100, a non-volatile storage device 220 such as a hard disk drive, a volatile storage device 230 such as a hard disk and a flash memory, an operation unit 260 such as button and a touch panel for acquiring a user's operation, a display unit 270 such as a liquid crystal monitor, and a communication unit 280, for example. The printer 200 is communicatively connected to an external device, for example, a terminal device (not shown) of a user via the communication unit 280.
The volatile storage device 230 provides a buffer area 231 for temporarily storing therein a variety of intermediate data that are generated when the CPU 210 performs processing. In the non-volatile storage device 220, a computer program CP is stored. In the first illustrative embodiment, the computer program CP is a control program for controlling the printer 200, and can be provided with being stored in the non-volatile storage device 220 upon shipment of the printer 200. Also, the computer program CP is provided to be downloaded from a server. Instead of this configuration, the computer program CP may be provided with being stored in a DVD-ROM or the like. The CPU 210 is configured to execute the computer program CP, thereby controlling the printing mechanism 100 to execute printing processing (which will be described later), for example.
The printing mechanism 100 is configured to perform printing by discharging respective inks (liquid droplets) of cyan (C), magenta (M), yellow (Y) and black (K). The printing mechanism 100 includes a printing head 110, a head drive unit 120, a main scanning unit 130 and a conveyance unit 140.
The conveyance unit 140 is configured to convey the sheet S along a conveyance path NR from the sheet feeding tray 20 to the sheet discharge tray 21 through a space between the printing head 110 and the platen 50. The conveyance path NR includes a curved path VR, which is a curved part, as seen in an X direction of
The conveyance unit 140 includes an outer guide member 18 and an inner guide member 19 configured to guide the sheet S along the conveyance path NR, and a pickup roller 143, a pair of upstream-side rollers 141 and a pair of downstream-side rollers 142 provided on the conveyance path NR.
The outer guide member 18 and the inner guide member 19 are arranged on the curved path VR. The outer guide member 18 is a member configured to support the sheet S from an outer surface (printing surface) with the sheet S being curved on the curved path VR. The inner guide member 19 is a member configured to support the sheet S from an inner surface (a surface opposite to the printing surface) with the sheet S being curved on the curved path VR.
The pickup roller 143 is mounted to a leading end of an arm 16 configured to be rotatable about a shaft AX1, and is configured to hold the sheet S by sandwiching the sheet S between the pickup roller and the sheet feeding tray 20. In other words, the pickup roller 143 is provided at a more upstream side of the conveyance path NR than the pair of upstream-side rollers 141, and is configured to hold the sheet S. The pickup roller 143 is configured to separate one sheet S from the plurality of sheets S accommodated in the sheet feeding tray 20 and to deliver the same onto the conveyance path NR.
The pair of upstream-side rollers 141 includes a drive roller 141a configured to be drive by a motor (not shown) and a driven roller 141b configured to rotate in association with rotation of the drive roller 141a. Likewise, the pair of downstream-side rollers 142 includes a drive roller 142a and a driven roller 142b. The driven roller 142b of the pair of downstream-side rollers 142 is a roller having a plurality of thin plate-shaped spurs concentrically arranged. This is not to damage a print image printed on the sheet S. The drive roller 141a, the driven roller 141b and the drive roller 142a are cylindrical rollers, for example.
The pair of upstream-side rollers 141 is configured to hold the sheet S at a more upstream side than the printing head 110. The pair of downstream-side rollers 142 is configured to hold the sheet S at a more downstream side than the printing head 110. In the meantime, the conveying direction AR of
The main scanning unit 130 includes a carriage 133 configured to mount thereto the printing head 110 and a slide shaft 134 configured to hold the carriage 133 to be reciprocally moveable in a main scanning direction (X-axis direction). The main scanning unit 130 is configured to reciprocally move the carriage 133 along the slide shaft 134 by using power of a main scanning motor (not shown). Thereby, a main scanning of reciprocally moving the printing head 110 in the main scanning direction is implemented.
The head drive unit 120 is configured to drive the printing head 110, which is configured to reciprocally move by the main scanning unit 130, on the sheet S to be conveyed by the conveyance unit 140. That is, the printing head 110 is configured to discharge the inks from the plurality of nozzles NZ of the printing head 110, thereby forming dots on the sheet S. Thereby, an image is printed on the sheet S.
A-2. Printing Processing
The CPU 210 (
In S20, the CPU 210 executes rasterization processing for the acquired image data to generate RGB image data to express colors of respective pixels by RGB values. Thereby, RGB image data is acquired as target image data of the first illustrative embodiment. The RGB values including three component values of red (R), green (G) and blue (B), for example.
In S30, the CPU 210 executes region specifying processing for the RGB image data (target image data). The region specifying processing is processing of specifying a character region and a non-character object region in an RGB image RI to be indicated by the RGB image data. The character region is a region indicative of a character, and the non-character object region is a region indicative of an object different from the character. The object different from the character means a part, which is different from a character, of parts (parts to be drawn by dots during the printing) having colors different from a background color (generally, white) corresponding to a ground color of the sheet S. The object different from the character includes a photograph, a drawing, and a background different from white.
In S40, the CPU 210 executes color conversion processing for the RGB image data to generate CMYK image data to express colors of respective pixels by CMYK values. The CMYK values are color values including component values (component values of C, M, Y, K) corresponding to color materials to be used for printing. The color conversion processing is executed by referring to a well-known look-up table, for example.
In S50, the CPU 210 executes halftone processing for the CMYK image data to generate dot data which expresses a dot formation state of each pixel for each color component of CMYK. Each pixel value of the dot data indicates the dot formation states of two gradations “there is no dot” and “there is a dot” or the dot formation states of four gradations “there is no dot”, “small”, “medium” and “large”. The halftone processing is executed using a well-known method such as a dithering method, an error diffusion method or the like. The dot data is image data indicative of the print image PI (
In S60, the CPU 410 executes pass data output processing by using the dot data. Specifically, the CPU 210 generates data (pass data), which corresponds to a single partial printing SP (which will be described later), of the dot data, adds a variety of control data to the pass data, and outputs the same to the printing mechanism 100. In the control data, data designating a conveyance amount of conveyance of the sheet S to be executed after the partial printing SP is included. As described in detail later, in the pass data output processing, the processing result of the region specifying processing in S30 is used.
Thereby, the CPU 210 can cause the printing mechanism 100 to print a print image. Specifically, the CPU 210 controls the head drive unit 120, the main scanning unit 130 and the conveyance unit 140 to alternately execute, a plurality of times, the partial printing SP and sheet conveyance T, repetitively, thereby performing the printing. In the single partial printing SP, while the single main scanning is performed with the sheet S being stationary on the platen 50, the inks are discharged from the nozzles NZ of the printing head 110 onto the sheet S, so that a part of an image to be printed is printed on the sheet S. The single sheet conveyance T is conveyance of moving the sheet S in the conveying direction AR by a predetermined conveyance amount. In the first illustrative embodiment, the CPU 210 causes the printing mechanism 100 to execute m (m: an integer of 3 or larger) partial printings SPm.
Here, in
Each of the 1-pass partial images NA1 to NA6 is formed by the single partial printing. Specifically, the 1-pass partial image NAk is formed only with the kth partial printing SPk, i.e., the partial printing SPk to be performed at the head position Pk.
The 2-pass partial images SA1 to SA3 are formed by the two partial printings. Specifically, the 2-pass partial image SAk is formed by the kth partial printing SPk and the (k+1)th partial printing SP(k+1). That is, the 2-pass partial image SAk is formed by the partial printing SPk to be performed at the head position Pk and the partial printing SP(k+1) to be performed at the head position P(k+1). A region in which the 2-pass partial image SAk is to be printed is a region in which dots are to be formed by both the two partial printings SPk and SP(k+1), and is referred to as an overlap region, too.
In the example of
In S110, the CPU 210 executes labeling processing for the object specifying data to specify a plurality of objects. Specifically, the CPU 210 allots one identifier to one region including one or more continuous object pixels, as one object. Then, the CPU 210 allots different identifiers to a plurality of objects spaced from each other. By the labeling processing, the plurality of objects is specified. In the example of
In S120, the CPU 210 selects one notice object from the plurality of specified objects.
In S130, the CPU 210 calculates an occupation rate PR of the object pixels for the notice object. The occupation rate PR is a ratio of the object pixels occupying a total number of pixels in a rectangle circumscribing the notice object. For example, when the character TX of
In S140, the CPU 210 determines whether the occupation rate PR is less than a threshold value TH1. The threshold value TH1 is empirically determined in advance by using an image including a character or a photograph. The threshold value TH1 is for example, 40% to 60%.
In the rectangle circumscribing the character, a thin line and a background (white background, in the first illustrative embodiment) exist, and an occupation ratio of the thin line including the object pixels is lower, as compared to the non-character object such as a photograph. The non-character object, particularly, the photograph has the higher occupation rate PR, as compared to the character, for example. For example, since the photograph is generally rectangular and the substantially entirety thereof consists of the object pixels, the occupation rate PR may be 80% or higher. For this reason, when the occupation rate PR is less than the threshold value TH1 (S140: YES), the CPU 210 determines the region circumscribing the notice object, as the character region, in S150. When the occupation rate PR is equal to or higher than the threshold value TH1 (S140: NO), the CPU 210 determines the region circumscribing the notice object, as the non-character region, in S160.
In S170, the CPU 210 determines whether all the specified objects have been processed as the notice object. When there is a not-processed object (S170: NO), the CPU 210 returns to S120 and selects the not-processed object. When all the objects have been processed (S170: YES), the CPU 210 ends the region specifying processing.
Subsequently, the pass data output processing in S60 of
In S205, the CPU 210 executes overlap region setting processing. The overlap region setting processing is processing of setting an overlap region in which a 2-pass partial image is to be formed by both the notice partial printing and the partial printing to be subsequently executed. For example, it is determined whether or not to set the overlap region. When the overlap region is to be set, a length thereof in the conveying direction (also referred to as ‘overlap length’) is determined. It can be said that the overlap length is a length in the conveying direction of a 2-pass partial image to be printed. For example, when the raster lines RL1 and RL2 of
In S210, the CPU 210 determines whether the notice raster line is located in the overlap region in which a 2-pass partial region is to be printed. Since the overlap length is determined in S205, the CPU 210 can determine whether the current notice raster line is located in the overlap region.
When the notice raster line is located in the overlap region (S210: YES), the CPU 210 acquires distribution pattern data PD corresponding to the notice raster line, in S215.
Here, the recording rates R2, R3 and R4 of
In a range in the conveying direction AR corresponding to the 2-pass partial image SA2 (
In the meantime,
The distribution pattern data PD is generated so that the above-described recording rates are to be implemented in correspondence to the positions in the conveying direction AR in the overlap region in which the 2-pass partial image is to be printed.
In S220, the CPU 210 distributes and saves data (referred to as notice raster data, too), which corresponds to the notice raster line, of the dot data in the output buffer and the primary save buffer, in accordance with the distribution pattern data PD. That is, data, which indicates dots to be formed by the notice partial printing, of the notice raster data is saved in the output buffer, and data, which indicates dots to be formed by the subsequent partial printing of the notice partial printing, is saved in the primary save buffer.
When the notice raster line is not located in the overlap region (S210: NO), the dots corresponding to the plurality of pixels included in the notice raster line should be all formed by the notice partial printing. Therefore, in this case, the CPU 210 saves the notice raster data of the dot data in the output buffer, in S225.
In S230, the CPU 210 determines whether the raster lines of the notice partial printing have been all processed as the notice raster line. For example, in the case where the partial printing SP1 performed at the head position P1 of
When the raster lines of the notice partial printing have been all processed (S230: YES), the dot data of the notice partial printing has been saved in the output buffer at that point in time. Therefore, in this case, in S235, the CPU 210 outputs the dot data of the notice partial printing to the printing mechanism 100, as the pass data. At this time, the pass data to be output is added with control data indicative of a conveyance amount of the sheet conveyance that is to be performed after the notice partial printing. The conveyance amount of the sheet conveyance that is to be performed after the notice partial printing is a value that is to be determined in correspondence to the overlap length to be determined in the overlap region setting processing (which will be described later) of S205. For example, when the overlap length is determined to be Ha, the CPU 210 calculates a value obtained by subtracting the overlap length Ha from the nozzle length D, as a conveyance amount TV of the sheet conveyance T, adds control data indicative of the conveyance amount TV to the pass data, and outputs the same.
In S240, the CPU 210 deletes the output pass data from the output buffer, and copies the data saved in the primary save buffer to the output buffer. For example, at a point in time at which the final raster line RL3 corresponding to the head position P1 of
When there is a not-processed raster line of the notice partial printing (S230: NO), the CPU 210 skips over S235 and S240.
In S245, the CPU 210 determines whether all the raster lines in the print image PI have been processed as the notice raster line. When there is a not-processed raster line (S245: NO), the CPU 210 returns to S200, and selects the not-processed raster line as the notice raster line. When all the raster lines have been processed (S245: YES), the CPU 210 ends the pass data output processing.
The overlap region setting processing in S205 of
In S310, the CPU 210 determines whether the non-character object region PA is located at an upstream end (i.e., an opposite end in the conveying direction AR, a lower end in
When the non-character object region PA is located at the upstream end of the notice partial region (S310: YES), the CPU 210 sets an overlap region having the overlap length Ha, as an overlap region in which a 2-pass partial image is to be formed by both the notice partial printing and the subsequent partial printing of the notice partial printing, in S320. The overlap region is a region including the upstream end of the notice partial region. For example, the conveyance amount TV of the sheet conveyance T that is to be performed after the notice partial printing is set as a value obtained by subtracting the length Ha from the nozzle length D (TV=D−Ha). As a result, for example, the conveyance amounts of the sheet conveyances T1 and T2 of
When the non-character object region PA is not located at the upstream end of the notice partial region (S310: NO), the CPU 210 determines whether the character region TA is located at the upstream end of the notice partial region, in S330. In the example of
When the character region TA is located at the upstream end of the notice partial region (S330: YES), the CPU 210 determines whether a size of the character located at the upstream end of the notice partial region is equal to or larger than a reference value, in S340. Specifically, the CPU 210 calculates lengths (the number of pixels) in the conveying direction AR of one or more character regions TA (refer to
When the size of the character located at the upstream end of the notice partial region is equal to or larger than the reference value (S340: YES), the CPU 210 sets an overlap region having an overlap length Hb, as the overlap region in which the 2-pass partial image is to be printed by both the notice partial printing and the subsequent partial printing of the notice partial printing, in S350. The overlap length Hb is shorter than the overlap length Ha (Ha>Hb). For example, the conveyance length TV of the sheet conveyance T to be performed after the notice partial printing is set to a value obtained by subtracting the overlap length Hb from the nozzle length D (TV=D−Hb). As a result, for example, the conveyance amount of the sheet conveyance T3 of
When the character region TA is not located at the upstream end of the notice partial region (S330: NO), the CPU 210 does not set an overlap region, in S360. In this case, neither the non-character region PA nor the character region TA is located at the upstream end of the notice partial region. Therefore, the conveyance amount TV of the sheet conveyance T to be performed after the notice partial printing is set to a value greater than the nozzle length D so that the downstream end (upper end in
When the size of the character located at the upstream end of the notice partial region is smaller than the reference value (S340: NO), the CPU 210 does not set an overlap region, in S360. In this case, a relatively small character is located at the upstream end of the notice partial region. Therefore, the conveyance amount TV of the sheet conveyance T to be performed after the notice partial printing is set to the nozzle length D (TV=D). For example, the conveyance amount of the sheet conveyance T4 in
The print image PI that is printed on the sheet S in accordance with the first illustrative embodiment is further described with reference to
In the print image PI, the non-character object region PA is located at the upstream end of the partial region RA1 that is to be printed by the partial printing SP1. For this reason, a 2-pass partial image SA1 having a length Ha is printed between the 1-pass partial image NA1 to be printed only by the partial printing SP1 and the 1-pass partial image NA2 to be printed only by the partial printing SP2.
Likewise, the non-character object region PA is located at the upstream end of the partial region RA2 that is to be printed by the partial printing SP2. For this reason, a 2-pass partial image SA2 having a length Ha is printed between the 1-pass partial image NA2 to be printed only by the partial printing SP2 and the 1-pass partial image NA3 to be printed only by the partial printing SP3. Meanwhile, in the example of
The non-character object region PA is not located at the upstream end of the partial region RA3 that is to be printed by the partial printing SP3, and a character region TA including relatively large characters TX3 is located. For this reason, a 2-pass partial image SA3 having a length Hb shorter than the length Ha is printed between the 1-pass partial image NA3 to be printed only by the partial printing SP3 and the 1-pass partial image NA4 to be printed only by the partial printing SP4.
The non-character object region PA is not located at the upstream end of the partial region RA4 that is to be printed by the partial printing SP4, and a character region TA including relatively small characters TX4 is located. For this reason, a 2-pass partial image is not printed between the 1-pass partial image NA4 to be printed only by the partial printing SP4 and the 1-pass partial image NA5 to be printed only by the partial printing SP5.
Neither the non-character object region PA nor the character region TA is located at the upstream end of the partial region RA5 that is to be printed by the partial printing SP5. For this reason, a 2-pass partial image is not printed between the 1-pass partial image NA5 to be printed only by the partial printing SP5 and the 1-pass partial image NA6 to be printed only by the partial printing SP6.
According to the first illustrative embodiment as described above, when the non-character object region PA is located at the upstream end of the notice partial region (for example, the partial region RA1) (YES in S310 of
Also, when the non-character object region PA is not located at the upstream end of the notice partial region (for example, the partial region RA4) (NO in S310 of
As a result, when the non-character object region PA is not located at the upstream end of the partial region RA4 and the character region TA including the characters TX4 is located, the region including the upstream end of the partial region RA4 is not set as the overlap region. That is, the dots of the region including the upper end of the partial region RA4 are formed only by the partial printing SP4 and are not formed by the partial printing SP5. Therefore, it is possible to suppress the character TX4 from being thickened. Also, in this case, since the sheet S is conveyed by the conveyance amount D greater than the conveyance amount (D−Ha) after the partial printing SP4, it is possible to increase the printing speed. Also, when the non-character object region PA is located at the upstream end of the partial region RA1, the region including the upper end of the partial region RA1 is set as the overlap region. Therefore, it is possible to suppress the banding from being noticeable in the print image PI.
More specifically, it is assumed that the print image is configured only by the 1-pass partial images. In this case, due to a deviation of the conveyance amount of the sheet S, a white stripe or a black stripe may occur at a boundary of the two 1-pass partial images adjacent to each other in the conveying direction AR. That is, a defect referred to as banding may be caused. The banding is difficult to be noticeable even when it appears on the thin line configuring the character, and is easily-noticeable when it appears in a relatively wide region such as a photograph. Also, in general, when the deviation of the conveyance amount of the sheet S occurs, the conveyance unit 190 is adjusted so that the two 1-pass partial images adjacent to each other in the conveying direction AR are to be superimposed. Thereby, the white stripe is suppressed and the black stripe is permitted. Since the black stripe is a phenomenon that a density of a stripe-shaped part increases, the black stripe is difficult to be noticeable even when it is generated in an image having a relatively high density, and is easily-noticeable when it is generated in an image having a relatively low density. Here, in general, a character has a color having a high density, in many cases, and a photograph may include a color having a low density. Like this, the banding is more difficult to be noticeable in the character than in the non-character object such as a photograph.
Here, when a 2-pass partial image is provided between the two 1-pass partial images, it is possible to suppress the defect referred to as banding. That is, in the case of the 2-pass partial image, since the dots on one raster line are formed by the two partial printings, it is possible to suppress all the dots on one raster line from deviating in the same manner with respect to all the dots on the other raster lines. Meanwhile, in the case of the 2-pass partial image, the thin line is likely to be thickened. The reason is that the dots formed by one partial printing of the 2-pass partial image may deviate with respect to the dots formed by the other partial printing in the main scanning direction or the conveying direction. For this reason, in the case of the 2-pass partial image, a defect that a character configured by the thin line is thickened is likely to occur. In the meantime, in the case of the non-character object such as a photograph, the defect is difficult to occur even though it is the 2-pass partial image.
Also, when the 2-pass partial image is provided, the printing speed decreases, as compared to a case where the 2-pass partial image is not provided, because the conveyance amount (for example, D−Ha) of one sheet conveyance T is decreased, as compared to the conveyance amount (for example, D) when the 2-pass partial image is not provided, as described above.
In the first illustrative embodiment, as shown in
Also, in the first illustrative embodiment, when the non-character object region PA is not located at the upstream end of the notice partial region (for example, the partial region RA3) (NO in S310 of
Also, in the first illustrative embodiment, in the region specifying processing (
As can be seen from the above descriptions, the conveying direction AR of the first illustrative embodiment is an example of the moving direction, the conveyance amount (D−Ha) is an example of the first movement amount, the conveyance amount D is an example of the second movement amount, and the conveyance amount (D−Hb) is an example of the third movement amount.
In a second illustrative embodiment, the content of the overlap region setting processing in S205 of
In S300 of
When the density of the character located at the upstream end of the notice partial region is less than the reference value (S340B: YES), the CPU 210 sets an overlap region having an overlap length Hb, as the overlap region in which a 2-pass partial image is to be printed by both the notice partial printing and the subsequent partial printing of the notice partial printing, in S350, like the case of
When the density of the character located at the upstream end of the notice partial region is equal to or higher than the reference value (S340B: NO), the CPU 210 sets an overlap region having an overlap length Hc, as the overlap region in which a 2-pass partial image is to be printed by both the notice partial printing and the subsequent partial printing of the notice partial printing, in S355B. The overlap length Hc is shorter than the overlap lengths Ha and Hb (Ha>Hb>Hc). For example, the conveyance amount TV of the sheet conveyance T to be printed after the notice partial printing is set to a value obtained by subtracting the overlap length Hc from the nozzle length D (TV=D−Hc). As a result, for example, the conveyance amount of the sheet conveyance T4b of
According to the second illustrative embodiment as described above, like the first illustrative embodiment, when the non-character object region PA is located at the upstream end of the notice partial region (for example, the partial region RA1) (YES in S310 of
Therefore, in the example of
Also, according to the second illustrative embodiment, when the non-character object region PA is not located at the upstream end of the notice partial region (for example, the partial region RA3 in
Also, according to the second illustrative embodiment, when the non-character object region PA is not located at the upstream end of the notice partial region (for example, the partial region RA5 in
As can be seen from the above descriptions, the conveying direction AR of the second illustrative embodiment is an example of the moving direction, the conveyance amount (D−Ha) is an example of the first movement amount, the conveyance amount (D−Hc) is an example of the second movement amount, and the conveyance amount (D−Hb) is an example of the third movement amount.
(1) The overlap region setting processing (
In this modified embodiment, when it is assumed that the print image PI of
(2) In the first illustrative embodiment, when the non-character object region PA is located at the upstream end of the notice partial region, the overlap region having the overlap length Ha is set, irrespective of whether the character region TA is located at the upstream end of the notice partial region (YES in S310 of
When the character region TA is not located at the upstream end of the notice partial region (S510: NO), the CPU 210 determines whether the non-character object region PA is located at the upstream end of the notice partial region, in S530. When the non-character object region PA is located at the upstream end of the notice partial region (S530: YES), the CPU 210 sets an overlap region, as the overlap region in which a 2-pass partial image is to be printed by both the notice partial printing and the subsequent partial printing, in S540. When the non-character object region PA is not located at the upstream end of the notice partial region (S530: NO), the CPU 210 does not set an overlap region, in S520.
As can be seen from the above descriptions, in this modified embodiment, when the character region TA is located at the upstream end of the notice partial region, the overlap region is not set, irrespective of whether the non-character object region PA is located at the upstream end of the notice partial region. When the character region TA is not located at the upstream end of the notice partial region and the non-character object region PA is located at the upstream end of the notice partial region, the overlap region is set.
(3) In the second illustrative embodiment, when the non-character object region PA is located at the upstream end of the notice partial region, the overlap region having the overlap length Ha is set (YES in S310 of
For example, in the overlap region setting processing of
(4) In the first illustrative embodiment, when the character region is located at the upstream end of the notice partial region (S330: YES, in
Also, the switching condition of the first illustrative embodiment may be other conditions. For example, when the size of the character is equal to or greater than the reference value or the density of the character is less than the reference value, the overlap region may be set, and when the size of the character is smaller than the reference value and the density of the character is equal to or greater than the reference value, the overlap region may not be set. Alternatively, when the color of the character is a specific color (for example, yellow, blue) in which the banding is easily-noticeable, the overlap region may be set, and when the color of the character is different from the specific color, the overlap region may not be set. The specific color may be determined in advance by a test, for example.
In the second illustrative embodiment, the overlap length of the overlap region is set to Hb or Hc, depending on whether the density of the character in the character region is less than the reference value. Instead of this configuration, also in the second illustrative embodiment, like the first illustrative embodiment, the overlap length of the overlap region may be set to Hb or Hc, depending on whether the size of the character in the character region is equal to or greater than the reference value. Also, the switching condition of the second illustrative embodiment may be other conditions, like the switching condition of the first illustrative embodiment.
(5) The region specifying processing (
Also, in the region specifying processing, for example, when the target image data before the rasterization processing of S20 is described by a predetermined page description language (for example, PostScript), the target image data includes a drawing command including character information indicative of an arrangement position (for example, coordinates) and a size of a character in the RGB image RI and a drawing command including non-character information indicative of an arrangement position and a size of a non-character object. In this case, the CPU 210 may specify the character region and the non-character region in the RGB image RI and the print image PI by using the character information and non-character information included in the target image data.
(6) In the illustrative embodiments, when setting the overlap region having the overlap length Ha (for example, S320 in
(7) As the printing medium, a film for OHP, a CD-ROM or a DVD-ROM may be adopted, instead of the sheet S, for example.
(8) In the illustrative embodiments, the printing mechanism 100 is a serial printer including the main scanning unit 130 and configured to drive the printing head 240 for partial printing during the main scanning. Instead of this configuration, the printing mechanism 100 may be a so-called line printer for which the main scanning unit 130 is not provided and a printing head having a plurality of nozzles aligned side by side over the substantially same length as a width of the sheet S in a direction perpendicular to the conveying direction and provided in multiple rows in the conveying direction is instead provided. In the line printer, the printing is executed without executing the main scanning. Also in this case, it is preferable that the partial printing for forming dots by the printing head and the conveyance of the sheet S by the conveyance unit are alternately executed multiple times for printing.
(9) In the printing mechanism 100 of the first illustrative embodiment, the conveyance unit 140 is configured to convey the sheet S, thereby moving the sheet S relative to the printing head 110 in the conveying direction AR. Instead of this configuration, the printing head 110 may be moved relative to the fixed sheet S in an opposite direction to the conveying direction AR, so that the sheet S may be moved relative to the printing head 110 in the conveying direction AR.
(10) In the respective illustrative embodiments, a device functioning as the control device for causing the printing mechanism 100 as the printing execution unit to execute the printing processing of
As can be seen from the above descriptions, in the illustrative embodiments, the printing mechanism 100 is an example of the printing execution unit, and when the terminal device executes the printing processing, the whole printer configured to execute the printing is an example of the printing execution unit.
Also, the control device for causing the printer to execute the printing processing of
(11) In the respective illustrative embodiments, a part of the configurations implemented by the hardware may be replaced with software, and a part or all of the configurations implemented by the software may be replaced with hardware. For example, a part of the processing that is to be executed by the CPU 210 of the printer 200 of
Although the present disclosure has been described with reference to the illustrative embodiments and the modified embodiments thereof, the embodiments are provided so as to easily understand the present disclosure, not to limit the present disclosure. The present disclosure can be changed and improved without departing from the gist and the claims, and the equivalents thereof are included in the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2018-066869 | Mar 2018 | JP | national |
This application is a Divisional of U.S. patent application Ser. No. 16/353,605, filed Mar. 14, 2019, which claims priority from Japanese Patent Application No. 2018-066869 filed on Mar. 30, 2018, the entire contents of both of which are incorporated herein by reference.
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| Notice of Reasons for Refusal issued in related Japanese patent application No. 2018-066869, dated Feb. 22, 2022. |
| Number | Date | Country | |
|---|---|---|---|
| 20210114380 A1 | Apr 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16353605 | Mar 2019 | US |
| Child | 17138075 | US |
