Printing apparatus

Abstract

To inhibit occurrence of mist.SOLUTION: A printing apparatus comprises: a head 10 that discharges liquid to a cloth 400; a platen 40 that holds the cloth 400; and height detection means 80 that detects the cloth 400 on the platen 40. The height detection means 80 has a light-emitting unit 80A and a light-receiving unit 80B. The light-emitting unit 80A emits emission light L1 at a first height h1 and second emission light L2 at a second height h2 lower than the first height h1. The light-receiving unit 80B receives the emission-light L1 at the first height h1 and the emission light L2 at the second height h2. The cloth 400 is detected at the first height h1 and the second height h2, and printing is performed when the cloth 400 is lower than the first height h1 and higher than the second height h2.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a printing apparatus.

Background Art

[0002] As a printing apparatus, there is a printing device that prints on a fabric such as a T-shirt.

[0003] Conventionally, there is known a device that includes a flexible detection plate on a carriage equipped with a recording head that discharges ink, and stops the carriage when it detects that the detection plate has contacted and flexed against a recording medium (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration disclosed in Patent Document 1, although it is possible to avoid contact when the distance between the head and the printing target is too close, there is a problem that it cannot detect a case where mist scatters when the distance between the head and the printing target is too far.

[0006] The present invention has been made in view of the above problems, and an object thereof is to suppress the generation of mist.

Means for Solving the Problems

[0007] To solve the above problems, a liquid ejection device according to the present invention includes: liquid ejection means for ejecting liquid onto a liquid ejection target; a holding member for holding the liquid ejection target; height detection means for detecting the liquid ejection target on the holding member, and is provided with: The height detection means detects the liquid discharge target at a first height and a second height lower than the first height. If the height detection means detects the liquid discharge target at the second height and does not detect the liquid discharge target at the first height, the liquid discharge means discharges liquid to the liquid discharge target. If, before the liquid dispensing means dispenses liquid onto the liquid dispensing target, and while the holding member holding the liquid dispensing target is being moved, the height detection means detects the liquid dispensing target at the first height, the detection operation by the height detection means is temporarily stopped, and after a predetermined time has elapsed, the height detection means performs the operation to detect the liquid dispensing target at the first height again at the stopped position. the result, If the height detection means detects the liquid discharge target at the first height, the movement of the holding member is stopped, or the holding member is moved toward the position where the liquid discharge target is set. If, before the liquid dispensing means dispenses liquid to the liquid dispensing target, and while the holding member holding the liquid dispensing target is being moved, the height detection means does not detect the liquid dispensing target at the first height and the second height, then the movement of the holding member is stopped, or the holding member is moved toward the position where the liquid dispensing target is set. This was the structure. [Effects of the Invention]

[0008] According to the present invention, the generation of mist can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view illustrating a printing apparatus according to a first embodiment of the present invention. [Figure 2] This is also a plan view diagram. [Figure 3] This is also a front view diagram. [Figure 4] This is a front explanatory view illustrating the height detection means in the first embodiment of the present invention. [Figure 5] This is a front view diagram illustrating the height detection operation and detection results using the height detection means. [Figure 6] This is also a front view diagram. [Figure 7] This is a block diagram illustrating the parts related to height detection and printing operation control in the same embodiment. [Figure 8] It is a flowchart for explaining the control of the printing operation by the printing control means in the same embodiment. [Figure 9] It is a flowchart for explaining the movement control to the printing standby position of the fabric (platen) including the control of the height detection operation by the printing control means in the same embodiment. [Figure 10] It is a flowchart for explaining the movement control to the printing standby position of the fabric (platen) including the control of the height detection operation by the printing control means in the second embodiment of the present invention. [Figure 11] It is a flowchart for explaining the movement control to the printing standby position of the fabric (platen) including the control of the height detection operation by the printing control means in the third embodiment of the present invention. [Figure 12] It is a perspective explanatory view of the main part for explaining the height adjustment mechanism of the height detection means in the fourth embodiment of the present invention. [Figure 13] It is also an enlarged perspective explanatory view. [Figure 14] It is also a front explanatory view.

Embodiments for Carrying out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The printing apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective explanatory view of the printing apparatus, FIG. 2 is a plan explanatory view thereof, and FIG. 3 is a front explanatory view thereof.

[0011] The printing apparatus 1 includes a carriage 11 mounted with a head 10 which is a liquid discharging means for discharging a liquid. Guide members 12 and 13 hold the carriage 11 so as to be reciprocally movable in the main scanning direction X. The carriage 11 is connected to a timing belt 17 wound around a driving pulley 15 rotated by a main scanning motor 14 and a driven pulley 16, and the carriage 11 is reciprocally moved in the main scanning direction X by driving the main scanning motor 14.

[0012] The encoder sheet 18 is arranged along the main scanning direction X. The encoder sheet 18 is provided with periodic slits. The carriage 11 has a reading sensor for reading the slits of the encoder sheet 18, and the position of the carriage 11 in the main scanning direction X can be detected from the reading result of the reading sensor.

[0013] The controller board 50 performs control to eject ink, which is a liquid, from the head 10 by timing according to the carriage position obtained from the reading result of the reading sensor of the carriage 11 at the ejection position.

[0014] Four heads 10 are mounted on the carriage 11. Each head 10 has two nozzle rows in which nozzles for ejecting liquid are arranged. The carriage 11 is also equipped with a sub-tank for temporarily storing the liquid supplied to the head 10. Liquid of the required color is sent from the main tank 21 to the sub-tank by a liquid feed pump via a supply tube.

[0015] The printing apparatus 1 includes a platen 40 which is a holding member for holding a fabric 400 as a printing target. The platen 40 is mounted on an elevating mechanism 41 so that its height in the vertical direction Z can be adjusted. The elevating mechanism 41 of the platen 40 is mounted on a slider 42. The slider 42 is movably placed on a slide rail 43 extending in the sub-scanning direction Y orthogonal to the main scanning direction X.

[0016] The slider 42 is reciprocated in the sub-scanning direction Y by a sub-scanning drive mechanism via a timing belt 45. When the slider 42 is reciprocated in the sub-scanning direction Y, the platen 40 is also reciprocated in the sub-scanning direction Y.

[0017] A maintenance unit 60 for maintaining and restoring the head 10 is located at one end in the main scanning direction. The maintenance unit 60 includes a suction cap 61 for capping the nozzle surface of the head 10, a moisturizing cap 62 for capping the nozzle surface of the head 10 for moisturizing, and a wiping member 63 for wiping the nozzle surface of the head 10. A suction pump is connected to the suction cap 61.

[0018] An ejection receiver 66 is located on the other end of the main scanning direction. The controller board 50 maintains and restores the head 10 by ejecting liquid from the head 10 to the ejection receiver 66 during printing.

[0019] Furthermore, at one end and the other end of the main scanning direction, a light-emitting section 80A and a light-receiving section 80B of a height detection means 80 for detecting the fabric 400 on the platen 40 are arranged. The height detection means 80 is attached to the frame 2.

[0020] Alternatively, a distance measuring sensor may be placed on the upper side of the platen 40 to perform height detection.

[0021] The printing device 1 also includes a power button 70, an operating unit 71, a power supply unit 72, and the like.

[0022] In this printing apparatus 1, when printing on fabric (the object to be printed), such as a T-shirt, the fabric 400 is set on the platen 40. Then, by operating the control unit 71, the platen 40 is pulled completely to the rear of the apparatus via the slider 42.

[0023] When the platen 40 is retracted, the height detection means 80 detects whether the fabric 400 on the platen 40 interferes with the head 10. If the head 10 and the fabric 400 collide, the retraction of the platen 40 is stopped, or the platen 40 is returned to the position where the fabric 400 is set.

[0024] When the platen 40 has been fully retracted, the printer enters a print data standby state. At this point, printing begins when the printer 1 receives print data from an external information processing device. Alternatively, if print data has been stored in the controller board 50 beforehand, printing begins when the printer selects the print data using the operation unit 71.

[0025] When controlling the printing process from a standby state, this control includes actions such as initiating printing, granting permission to print, moving to the next step in the workflow, and notifying the operator that printing is ready to begin.

[0026] When printing starts, the platen 40 is moved to the printing start position via the slider 42. Then, the carriage 11 moves and liquid is ejected from the head 10 to print one line. Once one line is printed, the platen 40 is moved one line via the slider 42. By repeatedly performing one scan of the carriage 11 and intermittent movement of the slider 42, printing is performed on the desired area of ​​the fabric 400. After printing is complete, the platen 40 is returned to the front of the device and printing ends.

[0027] Next, the height detection means in the first embodiment of the present invention will be described with reference to Figure 4. Figure 4 is a front explanatory view for the height detection means.

[0028] The height detection means 80 includes a first detection means 81 and a second detection means 82. The first detection means 81 detects the fabric 400 to be printed at a first height h1. The second detection means 82 detects the fabric 400 to be printed at a second height h2 which is lower than the first height h1.

[0029] The first detection means 81 has a light-emitting unit 81A and a light-receiving unit 81B. The light-emitting unit 81A emits light L1 at a first height h1, and the light-receiving unit 81B receives the emitted light L1 at the first height h1. When the emitted light L1 is incident on the light-receiving unit 81B, the state is such that the fabric 400 is not detected at the first height h1. When the emitted light L1 is not incident on the light-receiving unit 81B, the state is such that the fabric 400 is detected at the first height h1.

[0030] The second detection means 82 has a light-emitting unit 82A and a light-receiving unit 82B. The light-emitting unit 82A emits light L2 at a second height h2, and the light-receiving unit 82B receives the emitted light L2 at the second height h2. When the emitted light L2 is incident on the light-receiving unit 82B, the state is such that the fabric 400 is not detected at the second height h2. When the emitted light L2 is not incident on the light-receiving unit 82B, the state is such that the fabric 400 is detected at the second height h2.

[0031] Furthermore, the light-emitting section 81A of the first detection means 81 and the light-emitting section 82A of the second detection means 82 are combined to form the light-emitting section 80A of the height detection means 80, and the light-receiving section 81B of the first detection means 81 and the light-receiving section 82B of the second detection means 82 are combined to form the light-receiving section 80B of the height detection means 80.

[0032] Here, the first height h1 is the height at which the nozzle surface 10a of the head 10 does not come into contact with the fabric 400 to be printed on. The second height h2 is a predetermined distance at which the gap (spacing) between the nozzle surface (discharge surface) 10a of the head 10 and the surface of the fabric 400 is within an acceptable range when liquid is discharged from the head 10. Both the first height h1 and the second height h2 are located between the nozzle surface 10a of the head 10 and the platen 40.

[0033] When the height detection means 80 performs a detection operation to detect the height (surface height) of the fabric 400, the platen 40 is moved in the sub-scanning direction Y to scan a predetermined area of ​​the fabric 400. The predetermined area includes part or all of the area to be printed.

[0034] Here, the height detection operation and detection results by the height detection means will be explained with reference to Figures 5 and 6. Figures 5 and 6 are front explanatory views for the same explanation.

[0035] In the example shown in Figure 4, the emitted light L2 at the second height h2 is blocked by the fabric 400, while the emitted light L1 at the first height h1 is not blocked by the fabric 400. Therefore, the surface of the fabric 400 is higher than the second height h2 and lower than the second height h1.

[0036] At this time, the surface height of the fabric 400 is such that the head 10 and the fabric 400 do not interfere with each other, and the amount of mist generated remains within an acceptable range. In other words, if the surface of the fabric 400 is higher than the second height h2 and lower than the second height h1, there is no risk of the head 10 and the fabric 400 rubbing against each other during printing, and the scattering of mist is suppressed. Therefore, printing is performed in this state.

[0037] In the example shown in Figure 5, both the emitted light L2 at the second height h2 and the emitted light L1 at the first height h1 are blocked by the fabric 400, so the surface of the fabric 400 is higher than the first height h1.

[0038] At this time, the surface height of the fabric 400 is the height at which the head 10 and the fabric 400 come into contact, making it impossible to move the head 10 and perform printing.

[0039] In the example shown in Figure 6, since neither the emitted light L2 at the second height h2 nor the emitted light L1 at the first height h1 is blocked by the fabric 400, the surface of the fabric 400 is lower than the second height h2.

[0040] At this time, the surface height of the fabric 400 is so wide that the distance between the head 10 and the fabric 400 exceeds the mist's diameter range. When printing is performed, the liquid is scattered into fine particles, generating a large amount of mist. This mist can lead to device malfunctions, such as contamination of the encoder sheet 18 and reading sensor, preventing accurate detection of the carriage position. Therefore, printing cannot be performed at this time either.

[0041] Next, the parts of this embodiment related to height detection and control of printing operations will be explained with reference to the block diagram in Figure 7.

[0042] The printing control means 801 drives the head 10 via the head drive control unit 802. The printing control means 801 drives the main scanning motor 14 via the main scanning drive unit 803 to move the carriage 11 back and forth in the main scanning direction X. The printing control means 801 drives the sub-scanning motor 44 via the sub-scanning drive unit 804 to move the platen 40 back and forth in the sub-scanning direction Y.

[0043] The printing control means 801 receives the detection results of the first detection means 81 and the second detection means 82 of the height detection means 80 and determines whether the fabric 400 on the platen 40 has been detected at a first height h1 and a second height h2.

[0044] When the printing control means 801 performs a height detection operation of the fabric 400 on the platen 40, it drives the sub-scanning motor 44 via the sub-scanning drive unit 804 to move the platen 40 in the sub-scanning direction Y, and while doing so, it takes in the detection results of the first detection means 81 and the second detection means 82 of the height detection means 80 to determine whether or not the fabric 400 on the platen 40 has been detected at a first height h1 and a second height h2.

[0045] The print control means 801 then detects the fabric 400 at the second height h2 and controls the printing operation on the fabric 400 when it does not detect the fabric 400 at the first height h1.

[0046] Next, the control of the printing operation by the printing control means in the first embodiment of the present invention will be described with reference to the flowchart in Figure 8.

[0047] The printing control means 801 moves the platen 40 on which the fabric 400 is set to the retraction position at the rear of the device (which is also the printing standby position) (step S101, hereafter simply referred to as "S101").

[0048] Then, the printing operation begins (S102).

[0049] Next, the control of moving the fabric (platen) to the printing standby position, including the control of height detection operation by the printing control means, will be explained with reference to the flowchart in Figure 9.

[0050] Next, the control of moving the fabric (platen) to the printing standby position, including the control of the height detection operation by the printing control means in the first embodiment of the present invention, will be explained with reference to the flowchart in Figure 9.

[0051] First, set the variable S2 to "0" (step S1, hereafter referred to simply as "S1").

[0052] Next, a retraction operation is started to move the platen 40, on which the fabric 400 is set, to the rear of the device (S2).

[0053] Then, the first detection means 81 determines whether or not it has detected the fabric 400 at the first height h (SS3).

[0054] At this time, if the first detection means 81 has not detected the fabric 400 at the first height h, the second detection means 82 determines whether or not it has detected the fabric 400 at the second height h (S4).

[0055] Here, when the second detection means 82 detects the fabric 400 at the second height h, the variable S2 is set to "1" (S5).

[0056] Subsequently, if the second detection means 82 has not detected the fabric 400 at the second height h, it determines whether or not the platen 40 has reached the retraction end position (printing standby position) (S6).

[0057] If the platen 40 has not yet reached the end of its retraction position (printing standby position), the process returns to step S3 and is repeated.

[0058] In contrast, when the platen 40 reaches the end of its retraction position (printing standby position), the retraction operation is terminated (S8).

[0059] Then, it is determined whether the variable S2 is "1" or not (S9). If the variable S2 is "1", the process ends, indicating that the movement of the fabric 400 to the print waiting position was successful. If the variable S2 is not "1", the process ends, indicating that the movement of the fabric 400 to the print waiting position was unsuccessful.

[0060] On the other hand, in step S3, when the first detection means 81 detects the fabric 400 at a first height h1, the retraction operation of the platen 40 is terminated (S10), and the process is terminated as a failure to move the fabric 400 to the print standby position.

[0061] In other words, when the height detection means 80 detects the fabric 400 at a first height h1, the fabric 400 and the head 10 come into contact, so the detection operation is terminated and considered a failure.

[0062] Furthermore, if the fabric 400 is not detected by the height detection means 80 at either the first height h1 or the second height h2, and the print standby position (retraction end position) is reached, the gap between the head 10 and the fabric 400 will be too wide, which will lead to problems such as the generation of a large amount of mist, and the print will be considered a failure.

[0063] In contrast, if the height detection means 80 does not detect the fabric 400 at the first height h1, but detects the fabric 400 at the second height h2, the distance between the head 10 and the fabric 400 is appropriate, and the operation is considered successful.

[0064] The height detection control of the fabric 400 by moving the platen 40 to the print standby position is more effective in preventing contact between the head 10 and the fabric 400 and in preventing the generation of large amounts of mist if the scanning is performed across the entire sub-scanning direction of the platen 40.

[0065] Next, the control of moving the fabric (platen) to the printing standby position, including the control of the height detection operation by the printing control means in the second embodiment of the present invention, will be explained with reference to the flowchart in Figure 10.

[0066] First, steps S11 to S19 are the same processes as steps S1 to S19 in the first embodiment, so their explanation will be omitted.

[0067] In this embodiment, in step S13, when the first detection means 81 detects the fabric 400 at a first height h1, the retraction operation (relative movement) of the platen 40 is temporarily stopped (S20). Then, a predetermined time is waited (S21). After the predetermined time has elapsed, at the stopping position where the retraction operation of the platen 40 was stopped, it is determined again whether or not the first detection means 81 has detected the fabric 400 at the first height h1 (S22).

[0068] If the first detection means 81 has not detected the fabric 400 at the first height h1, the retraction operation of the platen 40 is resumed (S21), and the process returns to step 13 to continue the detection operation.

[0069] In response to this, if the first detection means 81 detects the fabric 400 again at the first height h1, the process is terminated as a failure to move the fabric 400 to the print standby position.

[0070] In other words, when the platen 40 is moved in the sub-scanning direction Y to perform the retraction operation, minute vibrations may occur in the platen 40. When the platen 40 vibrates, the fabric 400 resting on the platen 40 also vibrates. At this time, if the surface of the fabric 400 is near the detection limit of the first height h1 by the height detection means 80, the height fluctuation due to the vibration of the fabric 400 may be detected as the first height h1.

[0071] Therefore, when the height detection means 80 detects the fabric 400 at a first height h1, the movement of the platen 40 is temporarily stopped, and the system waits for a predetermined time until the vibration subsides. After the predetermined time has elapsed, the height detection means 80 is again checked to determine whether the fabric 400 is detected at the first height h1.

[0072] Then, in the subsequent detection by the height detection means 80, if the fabric 400 is not detected at the first height h1, the retraction operation of the platen 40 is restarted and the detection operation is resumed.

[0073] This eliminates the effects of vibrations in the platen 40, allowing for more accurate detection and preventing unnecessary printing.

[0074] In addition, when the height detection means 80 detects the fabric 400 at a second height h2, a second detection is not performed (S15), but a second detection can be performed in the same manner as described above.

[0075] Next, the control of moving the fabric (platen) to the printing standby position, including the control of the height detection operation by the printing control means in the third embodiment of the present invention, will be explained with reference to the flowchart in Figure 11.

[0076] First, steps S31 to S39 are the same processes as steps S1 to S19 in the first embodiment, so their explanation will be omitted.

[0077] In this embodiment, in step S33, when the first detection means 81 detects the fabric 400 at a first height h1, the retraction operation of the platen 40 is stopped (S40), and the platen 40 is moved back to the set position (initial position) where the fabric 400 is set (S41).

[0078] Then, the platen height is displayed as NG (faulty) on the control unit 71, and a restart button is also displayed to instruct the operator to resume operation after adjusting the height of the platen 40 (S42).

[0079] Subsequently, the user adjusts the height of the platen 40 (S43), and when the user presses the restart button, the process proceeds to step S31, and the detection operation is restarted from the beginning.

[0080] Furthermore, if the variable S2 is not equal to 1 in step S39, the process proceeds to step S41 to readjust the height of the platen 40.

[0081] This allows the height of the platen 40 to be adjusted and the operation to be resumed if the height of the fabric 400 is too high. Furthermore, the detection operation will resume even if the fabric 400 is reset and the operation restart button is pressed.

[0082] Furthermore, it includes a cancel button to instruct the system to cancel the detection operation and restart the operation from the beginning.

[0083] Next, a fourth embodiment of the present invention will be described with reference to Figures 12 to 14. Figure 12 is a perspective view illustrating the height adjustment mechanism of the height detection means in this embodiment, Figure 13 is an enlarged perspective view, and Figure 14 is a front view.

[0084] In this embodiment, the height detection means 80 includes a first detection means 81 and a second detection means 82. The first detection means 81 detects the fabric 400 at a first height h1. The second detection means 82 detects the fabric 400 at a second height h2.

[0085] The first detection means 81 consists of a light-emitting unit 81A that emits light in the main scanning direction and a light-receiving unit 81B that receives the emitted light. Similarly, the second detection means 82 consists of a light-emitting unit that emits light in the main scanning direction and a light-receiving unit 82B that receives the emitted light.

[0086] Furthermore, the light-receiving unit 81B of the first detection means 81 is height-adjustable by a height adjustment mechanism 90. The height adjustment mechanism 90 has an L-shaped bracket 91 to which the light-receiving unit 81B is attached. The height of the L-shaped bracket 91 can be adjusted by an adjustment screw 92 suspended from the frame 9 of the main body. The spring 93 applies pressure between the adjustment screw 92 and the L-shaped bracket 91 to maintain the distance specified by the adjustment screw 92 at all times. The light-emitting unit 81A of the first detection means 81 is also provided with a height adjustment mechanism 90.

[0087] In other words, since the fabric 400 has various thicknesses, if the first height h1 is fixed, it will not be able to accommodate when the fabric 400 becomes thicker. Therefore, by providing a height adjustment mechanism 90, which is a height adjustment means for adjusting the height of the first detection means 81, the first height h1 can be changed in response to changes in the thickness of the fabric 40.

[0088] In this embodiment, the first height h1, which is the detection height by the first detection means 81, can be changed, but the second height h2, which is the detection height by the second detection means 82, can also be changed in the same manner.

[0089] In this case, the first detection means 81 and the second detection means 82 can be height-adjustable independently, or the first detection means 81 and the second detection means 82 can be height-adjustable as a single unit.

[0090] Furthermore, for example, the height detection means can consist of a light-emitting means with multiple light-emitting units arranged in a row and a light-receiving means with multiple light-receiving units arranged in a row. By using such a height detection means, it is possible to adjust (change) the first height and the second height by selecting the light-emitting and light-receiving units to be used. In other words, the height detection means is not limited to being composed of separate first and second detection means.

[0091] In the above embodiment, the holding member is described as a tray, but it can also be a cassette or the like.

[0092] Furthermore, although the above embodiment describes the case where the printing target is fabric, the present invention is not limited to this. The present invention can also be applied similarly when printing is performed on a printing target other than fabric, by setting it in the holding member.

[0093] "A device for dispensing liquid" includes devices that have a liquid dispensing head or liquid dispensing unit and drive the liquid dispensing head to dispense liquid. A device for dispensing liquid includes not only devices that can dispense liquid onto surfaces to which liquid can adhere, but also devices that dispense liquid into air or into liquid.

[0094] This "liquid dispensing device" may also include means for feeding, transporting, and dispensing paper onto materials to which liquid can adhere, as well as pre-treatment devices, post-treatment devices, etc.

[0095] For example, "devices that dispense liquids" include image forming machines, which dispense ink to form images on paper, and three-dimensional molding machines, which dispense molding liquid into a powder layer formed in layers to create three-dimensional objects.

[0096] Furthermore, "devices that dispense liquid" are not limited to those that visualize meaningful images such as letters or figures through the dispensed liquid. For example, devices that form patterns that do not have meaning in themselves, or devices that create three-dimensional images, are also included.

[0097] The term "materials to which liquid can adhere" above refers to materials to which liquid can adhere, at least temporarily, including materials that adhere and solidify, or materials that adhere and penetrate. Specific examples include recording media such as paper, recording paper, film, and cloth; electronic components such as electronic circuit boards and piezoelectric elements; powder layers; organ models; and inspection cells. Unless otherwise specified, it includes all materials to which liquid can adhere.

[0098] The materials referred to as "materials to which liquid can adhere" above include paper, thread, fibers, fabrics, leather, metal, plastic, glass, wood, ceramics, etc., as long as liquid can adhere to them, even temporarily.

[0099] Furthermore, "liquid dispensing devices" include devices in which the liquid dispensing head and the surface to which the liquid can adhere move relative to each other, but are not limited to these. Specific examples include serial-type devices in which the liquid dispensing head moves, and line-type devices in which the liquid dispensing head does not move.

[0100] Other examples of "devices that dispense liquids" include processing liquid coating devices that dispense processing liquid onto the surface of paper for purposes such as modifying the surface of the paper, and injection granulation devices that granulate fine particles of raw materials by spraying a compositional solution, in which raw materials are dispersed in a solution, through a nozzle.

[0101] In this application, the terms image formation, recording, printing, copying, printing, and shaping are all considered synonymous.

[0102] The present invention is suitably used in a printing apparatus that dispenses a liquid containing pigment.

[0103] When using fabric as the printing surface, pigments are preferred because they exhibit minimal bleeding, good color development and lightfastness, and eliminate the need for post-printing cleaning. However, pigments are hard and can adhere to the nozzle surface, potentially damaging it through friction and causing poor ink discharge.

[0104] Therefore, if pigment adheres to the nozzle surface due to mist or other factors, it can damage the nozzle surface during subsequent nozzle surface cleaning operations, or the nozzle surface may be damaged by direct contact between the pigment adhering to the printing object and the nozzle surface.

[0105] Therefore, the present invention, which suppresses mist and provides stable printing operation without contact between the printing target and the nozzle surface, is preferably used when using a liquid (ink) containing pigment. [Explanation of Symbols]

[0106] 1 Printing device 10 Head (liquid dispensing means) 11 Carriage 40 Platen 80 Height detection means 81 First height detection means 82 Second height detection means 90 Height adjustment mechanism 400 fabrics 801 Printing control means

Claims

1. A liquid dispensing means for dispensing liquid to a target for liquid dispensing, A holding member for holding the liquid to be dispensed, The holding member includes a height detection means for detecting the liquid to be discharged, The height detection means detects the liquid discharge target at a first height and a second height lower than the first height. If the height detection means detects the liquid discharge target at the second height and does not detect the liquid discharge target at the first height, the liquid discharge means discharges liquid to the liquid discharge target. If, before the liquid dispensing means dispenses liquid onto the liquid dispensing target, and while the holding member holding the liquid dispensing target is being moved, the height detection means detects the liquid dispensing target at the first height, the detection operation by the height detection means is temporarily stopped, and after a predetermined time has elapsed, the height detection means performs the operation to detect the liquid dispensing target at the first height again at the stopped position. As a result, if the height detection means detects the liquid discharge target at the first height, the movement of the holding member is stopped, or the holding member is moved toward the position where the liquid discharge target is set. If, before the liquid dispensing means dispenses liquid to the liquid dispensing target, and while the holding member holding the liquid dispensing target is being moved, the height detection means does not detect the liquid dispensing target at the first height and the second height, then the movement of the holding member is stopped, or the holding member is moved toward the position where the liquid dispensing target is set. A liquid dispensing device characterized by the following features.

2. If, before the liquid dispensing means dispenses liquid to the liquid dispensing target, and while the holding member holding the liquid dispensing target is being moved, the height detection means does not detect the liquid dispensing target at the first height and the second height, then the liquid dispensing means will not dispense liquid to the liquid dispensing target. The liquid dispensing device according to feature 1.

3. The first height is such that the liquid to be dispensed does not come into contact with the dispensing surface of the liquid dispensing means. The second height is a height such that the distance between the liquid to be discharged and the discharge surface of the liquid discharge means is within a predetermined distance. The liquid dispensing device according to claim 1 or 2.

4. The height detection means is A first detection means for detecting the liquid discharge target at the first height, The system includes a second detection means for detecting the liquid discharge target at the second height, The first detection means and the second detection means are height-adjustable, either independently or as a single unit. A liquid dispensing device according to any one of the features 1 to 3.

5. The height detection means performs an operation to detect a predetermined area of ​​the liquid to be discharged. A liquid dispensing device according to any one of features 1 to 4.

6. After moving the holding member that holds the liquid discharge target from the position where the liquid discharge target is set to the liquid discharge standby position, The movement of the holding member and the discharge of liquid to the liquid discharge target by the liquid discharge means are repeated. After the liquid has been dispensed to the liquid-dispensing target by the liquid dispensing means, the holding member is moved to the position where the liquid-dispensing target is set. A liquid dispensing device according to any one of claims 1 to 5.

7. When the liquid dispensing means has not yet dispensed liquid to the liquid dispensing target, and the holding member holding the liquid dispensing target is being moved, the height detection means detects the liquid dispensing target at the first height, or if it does not detect the liquid dispensing target at either the first or second height, it shall report an error. A liquid dispensing device according to any one of features 1 to 6.

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