JP7069879B2 - Image forming device, image forming method, and program - Google Patents

Description

The present invention relates to an image forming apparatus, an image forming method, and a program.

An inkjet image forming apparatus capable of printing an image on an uneven recording medium such as clothes is used. In such an image forming apparatus, a mechanism for adjusting the gap (interval) between the ejection portion and the recording medium is required so that the ejection portion for ejecting ink does not come into contact with the convex portion of the recording medium.

For example, the unevenness information of the recording medium is acquired based on the amount of shaking generated by bringing the free swinging end of the swinging flap into contact with the unevenness of the recording medium, and the ejection unit and the recording medium are subjected to the acquired unevenness information. An image forming apparatus for adjusting an intervening gap is disclosed (Patent Document 1).

In order to avoid contact between the ejection part and the recording medium, the convex portion of the recording medium is detected, and the relative between the ejection portion and the recording medium so that a predetermined gap is formed between the ejection portion and the convex portion. It is necessary to adjust the target position. However, if the gap is set based only on the convex portion, the quality of the image printed on the concave portion may be impaired. Further, if the sequential gap is adjusted according to all the uneven shapes, the printing speed is greatly reduced. Therefore, in an inkjet image processing device that prints an image on an uneven recording medium, the print quality is improved without reducing the certainty of avoiding contact between the ejection unit and the recording medium and reducing the printing speed. It was difficult. Such a problem cannot be solved by the prior art.

The present invention has been made in view of the above, and an object of the present invention is to improve print quality without reducing the certainty of avoiding contact between the ejection unit and the recording medium and reducing the printing speed. ..

In order to solve the above-mentioned problems and achieve the object, the image forming apparatus according to the present invention includes a detection unit for detecting the uneven shape of the recording medium, a discharge unit for discharging liquid to the recording medium, and a discharge unit. Selection to select a gap candidate value that can avoid contact between the ejection unit and the recording medium from a plurality of gap candidate values registered as values that can guarantee print quality based on the information indicating the uneven shape. The unit includes an adjustment unit that adjusts the relative position between the discharge unit and the recording medium so that the gap between the discharge unit and the recording medium becomes the selected gap candidate value. The selection unit is the first gap when the virtual gap value, which is the sum of the height of the convex portion on the recording medium and the first margin for avoiding contact, is equal to or less than the first gap candidate value. When a candidate value is selected and the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap candidate value and a second margin for guaranteeing print quality. If it is less than or equal to the sum of, the first gap candidate value is selected, and if the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap candidate value. When it is larger than the sum of the second margin and the second gap, a second gap candidate value larger than the first gap candidate value is selected .

According to the present invention, it is possible to improve the print quality without causing a decrease in the certainty of avoiding contact between the ejection portion and the recording medium and a decrease in the printing speed.

FIG. 1 is a front view showing a configuration example of an image forming apparatus according to a first embodiment. FIG. 2 is a block diagram showing a configuration example of a control unit of the image forming apparatus according to the first embodiment. FIG. 3 is a front view showing an example of a method for detecting an uneven shape of a recording medium according to the first embodiment. FIG. 4 is a side view showing an example of a method for detecting an uneven shape of a recording medium according to the first embodiment. FIG. 5 is a block diagram showing a software configuration example of the control unit according to the first embodiment. FIG. 6 is a block diagram showing a functional configuration example of the plotter control unit according to the first embodiment. FIG. 7 is a block diagram showing a functional configuration example of the gap adjustment control unit according to the first embodiment. FIG. 8 is a side view showing an example of a gap between the recording medium and the carriage according to the comparative example. FIG. 9 is a diagram showing an example in which the virtual gap value according to the first embodiment is equal to or less than the first gap candidate value. FIG. 10 is a diagram showing an example in which the virtual gap value according to the first embodiment is larger than the first gap candidate value and equal to or less than the second gap candidate value. FIG. 11 is a flowchart showing an example of gap setting processing according to the first embodiment. FIG. 12 is a diagram showing an example of setting a gap in the image forming apparatus according to the second embodiment. FIG. 13 is a flowchart showing an example of gap setting processing according to the second embodiment. FIG. 14 is a block diagram showing a functional configuration example of the gap adjustment control unit according to the third embodiment. FIG. 15 is a diagram showing an example in the case where the convex portion and the print area according to the third embodiment overlap. FIG. 16 is a diagram showing an example in the case where the convex portion and the print area according to the third embodiment overlap. FIG. 17 is a flowchart showing an example of gap setting processing according to the third embodiment. FIG. 18 is a side view showing an example of a method for detecting an uneven shape of a recording medium according to a fourth embodiment. FIG. 19 is a side view showing an example of a method for detecting an uneven shape of a recording medium according to a fifth embodiment.

The image forming apparatus, the image forming method, and the embodiment of the program will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments, and the components in the following embodiments include those easily conceived by those skilled in the art, substantially the same, and so-called equal ranges. .. Various omissions, substitutions, changes, and combinations of components can be made without departing from the gist of the following embodiments.

(First Embodiment)
FIG. 1 is a front view showing a configuration example of the image forming apparatus 1 according to the first embodiment. The image forming apparatus 1 is an apparatus capable of printing on a recording medium 10 having irregularities such as clothes and cloth by an inkjet printing mechanism. The image forming apparatus 1 may be a printing-only machine or a multifunction device having a function other than printing (for example, a copying function, a scanner function, a facsimile function, etc.). In the figure, the X-axis corresponds to the main scanning direction (main moving direction of the carriage 12), the Y-axis corresponds to the sub-scanning direction (main moving direction of the recording medium 10), and the Z-axis corresponds to the vertical (vertical) direction. Corresponds to. The "front view" is a view when the main scanning direction is the left-right direction of the drawing.

The image forming apparatus 1 includes a platen 11, a carriage 12 (discharging portion), a light emitting element 13, and a light receiving element 14. The platen 11 is mounted with the recording medium 10 and is displaced at least in the sub-scanning direction and the vertical direction by an appropriate driving mechanism. The carriage 12 has a built-in ejection head that ejects ink (liquid), and is displaced at least in the main scanning direction by an appropriate drive mechanism. The light emitting element 13 is a device that emits a laser beam 15, and may be configured by using, for example, an LED or the like. The light emitting element 13 according to the present embodiment emits the laser beam 15 in the horizontal direction, that is, in the direction parallel to the main surface of the recording medium 10. The light receiving element 14 is a device that receives the laser light 15 emitted from the light emitting element 13 to generate an electric current, and may be configured by using a photoelectric conversion element or the like.

FIG. 2 is a block diagram showing a configuration example of the control unit 101 of the image forming apparatus 1 according to the first embodiment. The control unit 101 is an electronic control unit that controls the entire image forming apparatus 1, and in this example, the CPU (Central Processing Unit) 111, the ROM (Read Only Memory) 112, the RAM (Random Access Memory) 113, and the NVRAM ( Non-volatile Random Access Memory) 114, ASIC (Application Specific Integrated Circuit) 115, Host I / F (Interface) 116, I / O (Input / Output) Port 117, Print Control Unit 121, Main Scan Motor Drive Unit 122, The sub-scanning motor drive unit 123 and the gap adjusting unit 124 are included.

The CPU 111 executes various arithmetic processes for realizing the functions of the image forming apparatus 1 according to a program stored in the ROM 112 or the like. The ROM 112 stores programs, other fixed data, and the like. The RAM 113 is used as a storage area for temporarily holding the work area of the CPU 111, image data, and the like. The NVRAM 114 holds data even while the power is cut off, and is used as a rewritable storage area. The ASIC 115 is a circuit that performs image processing (for example, various signal processing for image data, sorting, etc.), other input / output signal processing, and the like. The host I / F 116 sends / receives data and signals to / from a printer driver 51 provided in a host such as an information processing device such as a personal computer, an image reading device such as an image scanner, and an image pickup device such as a digital camera. The I / O port 117 includes a detection signal from the main scanning encoder 55 that detects the position of the carriage 12 in the main scanning direction, a detection signal from the sub-scanning encoder 57 that detects the position of the recording medium 10 in the sub-scanning direction, and light receiving. The detection signal from the element 14 is received. The control unit 101 is connected to an operation panel 52 that enables input / output of various information with the user.

The print control unit 121 outputs a drive waveform composed of one or a plurality of drive pulses to the head driver 53 that controls the discharge head 21. The print control unit 121 may be configured by using a D / A converter, an amplifier, or the like that D / A-converts the pattern data of the drive pulse stored in the ROM 112 and read out by the CPU 111. The head driver 53 outputs a drive pulse generated based on image data (dot pattern data) corresponding to one line of the ejection head 21 serially input to the ejection head 21. The head driver 53 is, for example, a shift register for inputting a clock signal and serial data, a latch circuit for latching the resist value of the shift register with a latch signal, a level conversion circuit (level shifter) for changing the level of the output value of the latch circuit, and a level shifter. The drive pulse included in the drive waveform is selectively applied to the pressure generating means of the discharge head by controlling the on / off of the analog switch array, including the analog switch array whose on / off is controlled. The control unit 101 receives the print data or the like generated by the printer driver 51 via the network and the host I / F 116. The CPU 111 reads and analyzes the print data in the receive buffer included in the host I / F 116. The ASIC 115 performs necessary image processing, data rearrangement processing, and the like, and transfers the processed data to the print control unit 121. The print control unit 121 outputs image data, a drive waveform, and the like to the discharge head 21 in the carriage 12 at a timing based on the data received from the ASIC 115. Note that the dot pattern data for outputting the image data or the like may be generated using, for example, the font data stored in the ROM 112, or the image data may be expanded into bitmap data by the printer driver 51. May be good. Here, an example in which the dot pattern data is generated by the printer driver 51 is shown.

The main scanning motor drive unit 122 outputs a drive waveform that controls the main scanning motor 54 that displaces the carriage 12 in the main scanning direction. The main scanning motor 54 drives according to the drive waveform received from the main scanning motor drive unit 122, and displaces the carriage 12 in the main scanning direction. The main scanning encoder 55 outputs a detection signal indicating the position of the carriage 22 in the main scanning direction to the I / O port 117.

The sub-scanning motor drive unit 123 outputs a drive waveform that controls the sub-scanning motor 56 that displaces a member (platen 11 or the like) that displaces the recording medium 10 in the sub-scanning direction. The sub-scanning motor 56 drives according to the drive waveform received from the sub-scanning motor drive unit 123, and displaces the recording medium 10 in the sub-scanning direction. The sub-scanning encoder 57 outputs a detection signal indicating the position of the recording medium 10 in the sub-scanning direction to the I / O port 117.

The gap adjusting unit 124 outputs a drive waveform that controls the platen motor 58 that raises and lowers (displaces in the vertical direction) the platen 11 on which the recording medium 10 is placed. The platen motor 58 is driven according to the drive waveform received from the gap adjusting unit 124, changes the relative position between the recording medium 10 and the carriage 12, and changes the gap between the recording medium 10 and the carriage 12. Further, the gap adjusting unit 124 drives the light emitting element driver 59 that supplies the driving current to the light emitting element 13 while moving the platen 11 up and down. During this time, the detection signal detected by the light receiving element 14 is output to the I / O port 117. The gap adjusting unit 124 generates shape information indicating the uneven shape of the surface of the recording medium 10 based on the detection signal from the light receiving element 14, and creates a gap between the recording medium 10 and the carriage 12 based on the shape information. adjust.

FIG. 3 is a front view showing an example of a method for detecting an uneven shape of the recording medium 10 according to the first embodiment. As shown in FIG. 3, when the uneven shape of the recording medium 10 is detected, the platen 11 on which the recording medium 10 is placed is raised while the light emitting element 13 is emitting the laser beam 15, and the laser beam 15 is emitted. Is blocked by the recording medium 10 (when the light receiving element 14 no longer detects the laser beam 15), the platen 11 is stopped. The position of the platen 11 (recording medium 10) at this time corresponds to the height of the convex portion of the recording medium 10.

FIG. 4 is a side view showing an example of a method for detecting an uneven shape of the recording medium 10 according to the first embodiment. The "side view" is a view when the sub-scanning direction is the left-right direction of the drawing. As shown in FIG. 4, the platen 11 is shifted in the sub-scanning direction at predetermined detection intervals, and the convex portion 71 and the concave portion 72 are detected by the method shown in FIG. As a result, the heights of the convex portions 71 and the concave portions 72 can be detected at a plurality of locations of the recording medium 10, and the overall uneven shape of the recording medium 10 can be grasped.

FIG. 5 is a block diagram showing a software configuration example of the control unit 101 according to the first embodiment. The control unit 101 includes a printer unit 201, a panel control unit 202, a memory management unit 203, a system management unit 204, a communication control unit 205, a plotter control unit 206, and an OS (Operating System) 207.

The printer unit 201 controls the printing function. The panel control unit 202 controls the output to the operation panel 52, the input from the operation panel 52, and the like. The memory management unit 203 manages the RAM 113 and the like. The system management unit 204 manages non-volatile set values using the NVRAM 114. The communication control unit 205 controls the host I / F 116. The plotter control unit 206 controls the hardware related to printing. The operating system 207 performs basic processes for operating each of the above units 201 to 206, such as data input / output processing, hardware management processing, and process management processing.

FIG. 6 is a block diagram showing a functional configuration example of the plotter control unit 206 according to the first embodiment. The plotter control unit 206 includes a print processing unit 221, a gap adjustment control unit 222, a main scanning motor drive control unit 223, and a sub-scanning motor drive control unit 224.

The print processing unit 221 performs processing by the print control unit 121, that is, processing for controlling the head driver 53 based on image data and the like. The gap adjustment control unit 222 performs processing by the gap adjustment unit 124, that is, a process of raising and lowering the platen 11 so as to secure an appropriate gap between the recording medium 10 and the carriage 12. The main scanning motor drive control unit 223 performs processing by the main scanning motor drive unit 122, that is, processing for displacing the carriage 12 in the main scanning direction and the like. The sub-scanning motor drive control unit 224 performs processing by the sub-scanning motor drive unit 123, that is, processing for displacing a member (platen 11 or the like) that displaces the recording medium 10 in the sub-scanning direction.

FIG. 7 is a block diagram showing a functional configuration example of the gap adjustment control unit 222 according to the first embodiment. The gap adjustment control unit 222 includes a shape detection unit 241, a shape storage unit 242, a gap candidate value management unit 243, and a selection unit 244.

The shape detection unit 241 performs a process for detecting the uneven shape of the recording medium 10 by, for example, a detection method as shown in FIGS. 3 and 4. The shape storage unit 242 performs a process for storing shape information indicating the uneven shape of the storage medium 10 detected by the shape detection unit 241.

The gap candidate value management unit 243 manages (reads, writes, updates, etc.) a plurality of gap candidate values used when setting a gap between the recording medium 10 and the carriage 12. The gap candidate value is a plurality of fixed values registered as gap values that can guarantee print quality. The gap candidate value is based on, for example, experimental results and simulation results of an experiment in which the gap between the recording medium 10 and the carriage 12 is variously changed for printing, and the relationship between each gap and the image quality of the printed matter is investigated. It can be a derived value. The selection unit 244 selects one gap candidate value from a plurality of gap candidate values managed by the gap candidate value management unit 243 based on the shape information stored in the shape storage unit 242.

FIG. 8 is a side view showing an example of the gap G between the recording medium 10 and the carriage 12 according to the comparative example. The recording medium 10 includes a convex portion (for example, a shirt pocket portion or the like) 71 and a concave portion (for example, a portion serving as a base of the shirt pocket) 72. The gap G according to this example is the distance from the concave portion 72, which is the main printing surface, to the carriage 12, and is the height H of the convex portion 71 and the non-contact guarantee margin α (first) for guaranteeing contact avoidance. It is the sum of the margin). That is, the gap G according to the comparative example is set with reference to the height H of the convex portion 71, and does not consider the relationship with the concave portion 72. According to such a method, it is possible to prevent the carriage 12 from coming into contact with the convex portion 71, but there is a high possibility that the quality of printing made on the concave portion 72 will be impaired.

Therefore, the selection unit 244 of the gap adjustment control unit 222 according to the present embodiment can avoid contact between the carriage 12 and the recording medium 10 (convex portion 71) from among a plurality of gap candidate values that can guarantee print quality. Select a suitable gap candidate value. Then, the selected gap candidate value is set as the gap G between the print surface (for example, the recess 72) of the recording medium 10 and the carriage 12. The following shows an example in which two gap candidate values G1 and G2 (G1 <G2) are registered.

FIG. 9 is a diagram showing an example in which the virtual gap value Gp according to the first embodiment is equal to or less than the first gap candidate value G1. As shown in FIG. 9, when the virtual gap value Gp (H + α) is equal to or less than the first gap candidate value G1, the first gap candidate value G1 is set as the gap G.

FIG. 10 is a diagram showing an example in which the virtual gap value Gp according to the first embodiment is larger than the first gap candidate value G1 and equal to or less than the second gap candidate value G2. As shown in FIG. 10, when the virtual gap value Gp (H + α) is larger than the first gap candidate value G1 and equal to or less than the second gap candidate value G2, the second gap candidate value G2 is regarded as the gap G. Set.

FIG. 11 is a flowchart showing an example of setting processing of the gap G according to the first embodiment. First, the gap adjustment control unit 222 (selection unit 244) sets the sum of the height H of the convex portion and the non-contact guarantee margin α as the virtual gap value Gp (S101), and the virtual gap value Gp is the first gap candidate value. It is determined whether or not it is G1 or less (S102). When the virtual gap value Gp is equal to or less than the first gap candidate value G1 (Gp ≦ G1) (S102: Yes), the gap adjustment control unit 222 sets the first gap candidate value G1 to the gap G (S103). ..

On the other hand, when the virtual gap value Gp is not equal to or less than the first gap candidate value G1 (Gp> G1) (S102: No), the gap adjustment control unit 222 has the virtual gap value Gp equal to or less than the second gap candidate value G2. It is determined whether or not (Gp ≦ G2) (S104). When the virtual gap value Gp is equal to or less than the second gap candidate value G2 (Gp> G1 and Gp ≦ G2) (S104: Yes), the gap adjustment control unit 222 sets the second gap candidate value G2 to the gap G. (S105).

On the other hand, when the virtual gap value Gp is not equal to or less than the second gap candidate value G2 (Gp> G2) (S104: No), the gap adjustment control unit 222 sets the virtual gap value Gp to the gap G (S106). ..

In the above embodiment, an example of using two gap candidate values G1 and G2 is shown, but two or more gap candidate values may be used.

Further, in the above embodiment, the configuration in which the gap G between the recording medium 10 and the carriage 12 is adjusted by raising and lowering the platen 11 is exemplified, but the mechanism for adjusting the gap G is not limited to this. For example, a mechanism or the like that displaces the carriage 12 in the vertical direction may be used.

The program that realizes the function of the image forming apparatus 1 is a file in an installable format or an executable format that can be read by a computer such as a CD-ROM, a memory card, a CD-R, or a DVD (Digital Versatile Disk). It is stored on a medium and provided as a computer program product.

Further, the program may be stored on a computer connected to a network such as the Internet and provided by downloading via the network. Further, the program may be configured to be provided via a network such as the Internet without being downloaded. Further, the program may be configured to be provided by incorporating it into an appropriate storage medium of the image forming apparatus 1 in advance. Further, the program may have a modular configuration including functions that can be realized by the program among the functional units included in the image forming apparatus 1. The function realized by the program is loaded into the main storage device (RAM 113 or the like) by reading the program from the storage medium and executing the program. That is, the functions realized by the program are generated on the main memory.

As described above, according to the present embodiment, a gap candidate value that can avoid contact between the carriage 12 and the recording medium 10 is selected from a plurality of gap candidate values G1 and G2 that can guarantee print quality, and is selected. The set gap candidate value is set in the gap G between the print surface of the recording medium 10 and the carriage 12. This makes it possible to improve the print quality without reducing the certainty of avoiding contact between the carriage 12 and the recording medium 10 and the printing speed.

Hereinafter, other embodiments will be described with reference to the drawings, but the same reference numerals may be given to parts that have the same or similar effects as those of the first embodiment, and the description thereof may be omitted.

(Second embodiment)
The second embodiment is different from the first embodiment in that a quality assurance margin is set for the gap candidate values G1 and G2.

FIG. 12 is a diagram showing a setting example of the gap G in the image forming apparatus 1 according to the second embodiment. The virtual gap value Gp (sum of the height H of the convex portion and the non-contact guarantee margin α) according to this example is larger than the first gap candidate value G1, but the first gap candidate value G1 and the quality guarantee margin β. It is less than the sum of. In such a case, the gap G from the printed surface (recessed portion 72) to the carriage 12 is set to the first gap candidate value G1.

FIG. 13 is a flowchart showing an example of setting processing of the gap G according to the second embodiment. First, the gap adjustment control unit 222 (selection unit 244) sets the sum of the height H of the convex portion and the non-contact guarantee margin α as the virtual gap value Gp (S201), and the virtual gap value Gp is the first gap candidate value. It is determined whether or not it is G1 or less (S202). When the virtual gap value Gp is equal to or less than the first gap candidate value G1 (Gp ≦ G1) (S202: Yes), the gap adjustment control unit 222 sets the first gap candidate value G1 as the gap G (S203). ..

On the other hand, when the virtual gap value Gp is not equal to or less than the first gap candidate value G1 (Gp> G1) (S202: No), the gap adjustment control unit 222 has the virtual gap value Gp as the first gap candidate value G1. It is determined whether or not it is equal to or less than the sum of the quality assurance margin β (Gp ≦ G1 + β) (S204). When the virtual gap value Gp is equal to or less than the sum of the first gap candidate value G1 and the quality assurance margin β (Gp ≦ G1 + β) (S204: Yes), the gap adjustment control unit 222 sets the first gap candidate value G1. It is set as the gap G (S203).

On the other hand, when the virtual gap value Gp is not less than or equal to the sum of the first gap candidate value G1 and the quality assurance margin β (Gp> G1 + β) (S204: No), the gap adjustment control unit 222 uses the virtual gap value. It is determined whether or not Gp is equal to or less than the second gap candidate value G2 (Gp ≦ G2) (S205). When the virtual gap value Gp is equal to or less than the second gap candidate value G2 (Gp ≦ G2) (S205: Yes), the gap adjustment control unit 222 sets the second gap candidate value G2 as the gap G (S206). ..

On the other hand, when the virtual gap value Gp is not equal to or less than the second gap candidate value G2 (Gp> G2) (S205: No), the gap adjustment control unit 222 sets the virtual gap value Gp to the gap G (S207). ..

In the above, the case where the quality assurance margin is not set for the second gap candidate value G2 is illustrated, but as with the first gap candidate value G1, the quality assurance for the second gap candidate value G2 is also performed. The margin β may be set. In this case, even when Gp> G2, the second gap candidate value G2 is set in the gap G when Gp ≦ G2 + β is satisfied.

According to this embodiment, in addition to the effect of the first embodiment, it is possible to carry out an operation with a high priority of quality assurance.

(Third embodiment)
The third embodiment is different from the first embodiment in that a gap is set in consideration of the overlap between the convex portion 71 on the recording medium 10 and the print area.

FIG. 14 is a block diagram showing a functional configuration example of the gap adjustment control unit 301 according to the third embodiment. The gap adjustment control unit 301 according to the present embodiment includes a shape detection unit 241, a shape storage unit 242, a gap candidate value management unit 243, a selection unit 244, an image data acquisition unit 311, and an overlap determination unit 312.

The image data acquisition unit 311 acquires image data indicating the configuration of an image printed on the recording medium 10. The overlap determination unit 312 overlaps the uneven shape of the recording medium 10 with the print area on which the image is printed, based on the shape information stored in the shape storage unit 242 and the image data acquired by the image data acquisition unit 311. Is determined. The selection unit 244 can avoid contact between the carriage 12 and the recording medium 10 from among a plurality of gap candidate values based on the shape information and the overlap information (information indicating the overlap between the uneven shape and the print area). At the same time, select a gap candidate value that matches the uneven shape of the print area.

FIG. 15 is a diagram showing an example in which the convex portion 71 and the print area 81 according to the third embodiment overlap. In this example, the image is printed not only on the concave portion 72 of the recording medium 10 but also on the convex portion 71.

FIG. 16 is a diagram showing an example in the case where the convex portion 71 and the print area 81 according to the third embodiment do not overlap. In this example, the image is printed only on the concave portion 72 of the recording medium 10 and not on the convex portion 71.

FIG. 17 is a flowchart showing an example of setting processing of the gap G according to the third embodiment. When the image data acquisition unit 311 acquires the image data (S301), the overlap determination unit 312 has the convex portion 71 and the print area based on the shape information stored in the shape storage unit 242 and the acquired image data. It is determined whether or not they overlap (S302).

When the convex portion 71 and the print area overlap (S302: Yes), the selection unit 244 selects the gap candidate value with the convex portion 71 as a reference (S303). On the other hand, when the convex portion 71 and the print area do not overlap (S302: No), the selection unit 244 selects the gap candidate value with the concave portion 72 as a reference (S304).

According to the present embodiment, when an image is printed on the convex portion 71, a gap is set in consideration of the print quality on the convex portion 71. This makes it possible to further improve the print quality.

(Fourth Embodiment)
The fourth embodiment is different from the first embodiment in the method of detecting the uneven shape of the recording medium 10.

FIG. 18 is a side view showing an example of a method for detecting an uneven shape of the recording medium 10 according to the fourth embodiment. FIG. 18 shows a change in the positional relationship between the light emitting element 13 and the recording medium 10 (platen 11) in the detection method according to the present embodiment.

First, the platen 11 is raised while the light emitting element 13 is located at the end of the recording medium 10 (state 401), and when the recording medium 10 is detected by the laser beam 15 from the light emitting element 13 (the light receiving element 14 is used). The platen 11 is stopped (state 402) (when the laser beam 15 is no longer received). After that, the platen 11 is lowered, and when the recording medium 10 is no longer detected by the laser beam 15 from the light emitting element 13 (when the light receiving element 14 receives the laser beam 15), the platen 11 is stopped (state 403). .. After that, the platen 11 is moved in the sub-scanning direction, and when the recording medium 10 is detected by the laser beam 15 from the light emitting element 13, the platen 11 is stopped (state 404). After that, the platen 11 is lowered, and when the recording medium 10 is no longer detected by the laser beam 15 from the light emitting element 13, the platen 11 is stopped (state 405). After that, the platen 11 is moved in the sub-scanning direction (state 406).

According to the uneven shape detection method according to the present embodiment, the total vertical movement distance of the platen 11 is shorter than that of the detection method according to the first embodiment (see FIG. 4), so that it is necessary to detect the uneven shape. It is possible to shorten the time. Further, in the detection method of raising and lowering the platen 11 at predetermined detection intervals as in the first embodiment, if the detection interval is widened, the detection omission of the convex portion 71 may occur. By sliding the platen 11 in the horizontal direction (sub-scanning direction) with respect to the height of the concave portion 72 as described above, it is possible to prevent the detection omission of the convex portion 71.

(Fifth Embodiment)
The fifth embodiment is different from the first and fourth embodiments in the method of detecting the uneven shape of the recording medium 10.

FIG. 19 is a side view showing an example of a method for detecting an uneven shape of the recording medium 10 according to the fifth embodiment. The detection method according to the present embodiment uses two light emitting elements 13A and 13B arranged along the vertical direction. Two light receiving elements 14 are also arranged so as to correspond to these light emitting elements 13A and 13B. FIG. 19 shows a change in the positional relationship between the light emitting element 13 and the recording medium 10 (platen 11) in the detection method according to the present embodiment.

First, the platen 11 is raised in a state where the light emitting elements 13A and 13B are located at the end of the recording medium 10 (state 501), and the recording medium is generated by the laser light 15 from the first light emitting element 13A arranged at the upper part. When 10 is detected, the platen 11 is stopped (state 502). After that, the platen 11 is lowered, and when the recording medium 10 is no longer detected by the laser beam 15 from the first light emitting element 13A, the platen 11 is stopped (state 503). After that, the platen 11 is moved in the sub-scanning direction, and when the recording medium 10 is detected by the laser beam 15 from the first light emitting element 13A, the platen 11 is stopped (state 504). After that, the platen 11 is lowered, and when the recording medium 10 is no longer detected by the laser beam 15 from the first light emitting element 13A, the platen 11 is stopped (state 505). After that, the platen 11 is moved in the sub-scanning direction (state 506), and the platen 11 is stopped when the recording medium 10 is no longer detected by the laser beam 15 from the second light emitting element 13B arranged at the bottom (state 507). .. After that, the platen 11 is lowered, and when the recording medium 10 is detected by the laser beam 15 from the first light emitting element 13A, the platen is stopped (state 508).

As described above, according to the present embodiment, the start end (right end in FIG. 19) of the convex portion 71 is detected by the first light emitting element 13A arranged at the upper part, and the second light emitting element 13B arranged at the lower part is detected. The end of the convex portion 71 (the left end in FIG. 19) is detected by the above. In the method for detecting the uneven shape according to the fourth embodiment, the height of the concave portion 72 existing behind the convex portion 71 (left side in FIG. 18) cannot be detected, but the uneven shape according to the present embodiment cannot be detected. According to the detection method of, it is possible to detect the height of the concave portion 72 existing behind the convex portion 71. This makes it possible to shorten the detection time and improve the detection accuracy.

Although the embodiments of the present invention have been described above, the above embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other embodiments, and various omissions, replacements, changes, and combinations can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

1 Image forming device 10 Recording medium 11 Platen 12 Carriage 13 Light emitting element 14 Light receiving element 15 Laser light 21 Discharge head 51 Printer driver 52 Operation panel 53 Head driver 54 Main scanning motor 55 Main scanning encoder 56 Sub scanning motor 57 Sub scanning encoder 58 Platen Motor 59 Light emitting element driver 71 Convex part 72 Concave part 81 Printing area 101 Control unit 111 CPU
112 ROM
113 RAM
114 NVRAM
115 ASIC
116 Host I / F
117 I / O port 121 Print control unit 122 Main scan motor drive unit 123 Sub scan motor drive unit 124 Gap adjustment unit 201 Printer unit 202 Panel control unit 203 Memory management unit 204 System management unit 205 Communication control unit 206 Plotter control unit 207 OS
221 Print processing unit 222,301 Gap adjustment control unit 223 Main scanning motor drive control unit 224 Sub-scanning motor drive control unit 241 Shape detection unit 242 Shape storage unit 243 Gap candidate value management unit 244 Selection unit 311 Image data acquisition unit 312 Overlap judgment Part 401 to 406, 501 to 508 State G Gap G1 First gap candidate value G2 Second gap candidate value Gp Virtual gap value H Height α Non-contact guarantee margin β Quality guarantee margin

Japanese Unexamined Patent Publication No. 2013-128916

Claims (6)

A detector that detects the uneven shape of the recording medium,
A discharge unit that discharges liquid to the recording medium,
Selection to select a gap candidate value that can avoid contact between the ejection unit and the recording medium from a plurality of gap candidate values registered as values that can guarantee print quality based on the information indicating the uneven shape. Department and
An adjusting unit that adjusts the relative position between the discharging unit and the recording medium so that the gap between the discharging unit and the recording medium becomes the selected gap candidate value.
Equipped with
The selection unit is the first when the virtual gap value, which is the sum of the height of the convex portion on the recording medium and the first margin for avoiding contact, is equal to or less than the first gap candidate value. When a gap candidate value is selected and the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap candidate value and a second margin for guaranteeing print quality. If it is less than or equal to the sum of, the first gap candidate value is selected, and if the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap candidate. An image forming apparatus that selects a second gap candidate value larger than the first gap candidate value when the value is larger than the sum of the second margin . A detector that detects the uneven shape of the recording medium,
A discharge unit that discharges liquid to the recording medium,
Selection to select a gap candidate value that can avoid contact between the ejection unit and the recording medium from a plurality of gap candidate values registered as values that can guarantee print quality based on the information indicating the uneven shape. Department and
An adjusting unit that adjusts the relative position between the discharging unit and the recording medium so that the gap between the discharging unit and the recording medium becomes the selected gap candidate value.
An overlap determination unit that determines the overlap between the uneven shape and the print area,
Equipped with
When the convex portion on the recording medium and the print area overlap with each other, the selection portion can avoid contact between the ejection portion and the convex portion from the plurality of gap candidate values, and the selection portion can avoid contact with the convex portion. An image forming apparatus that selects the gap candidate value that can guarantee the print quality for printing on a convex portion. A detector that detects the uneven shape of the recording medium,
A discharge unit that discharges liquid to the recording medium,
Selection to select a gap candidate value that can avoid contact between the ejection unit and the recording medium from a plurality of gap candidate values registered as values that can guarantee print quality based on the information indicating the uneven shape. Department and
An adjusting unit that adjusts the relative position between the discharging unit and the recording medium so that the gap between the discharging unit and the recording medium becomes the selected gap candidate value.
Equipped with
The detector is
It includes a light emitting element that emits light in the horizontal direction for detecting the presence of the recording medium, and a mechanism that displaces the recording medium in the horizontal and vertical directions.
An image forming apparatus that detects a convex portion of the recording medium by displacing the recording medium in the vertical direction to detect a concave portion on the recording medium and then displacing the recording medium in the horizontal direction. The detector is
It comprises a plurality of said light emitting elements arranged along the vertical direction, and includes a plurality of the light emitting elements.
The first light emitting element arranged at the upper part detects the start end of the convex portion, and the second light emitting element arranged at the lower part detects the end of the convex portion.
The image forming apparatus according to claim 3 . Steps to detect the uneven shape of the recording medium,
Based on the information indicating the uneven shape, it is possible to avoid contact between the ejection unit that ejects the liquid to the recording medium and the recording medium from among a plurality of gap candidate values registered as values that can guarantee the print quality. Steps to select gap candidate values and
A step of adjusting the relative position between the ejection unit and the recording medium so that the gap between the ejection unit and the recording medium becomes the selected gap candidate value.
Including
In the selection step, when the virtual gap value, which is the sum of the height of the convex portion on the recording medium and the first margin for avoiding contact, is equal to or less than the first gap candidate value, the first When the gap candidate value is selected and the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap candidate value and a second gap for guaranteeing print quality. If it is less than or equal to the sum of the margins, the first gap candidate value is selected, and if the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap. An image forming method in which a second gap candidate value larger than the first gap candidate value is selected when the sum of the candidate value and the second margin is larger . On the computer
Processing to detect the uneven shape of the recording medium and
Based on the information indicating the uneven shape, it is possible to avoid contact between the ejection unit that ejects the liquid to the recording medium and the recording medium from among a plurality of gap candidate values registered as values that can guarantee the print quality. The process of selecting gap candidate values and
A process of adjusting the relative position between the ejection unit and the recording medium so that the gap between the ejection unit and the recording medium becomes the selected gap candidate value.
To execute ,
In the selected process, when the virtual gap value, which is the sum of the height of the convex portion on the recording medium and the first margin for avoiding contact, is equal to or less than the first gap candidate value, the first When the gap candidate value is selected and the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap candidate value and a second gap for guaranteeing print quality. If it is less than or equal to the sum of the margins, the first gap candidate value is selected, and if the virtual gap value is larger than the first gap candidate value, and the virtual gap value is the first gap. A program that selects a second gap candidate value that is larger than the first gap candidate value if it is larger than the sum of the candidate value and the second margin .

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