Plate making apparatus

Abstract

To remove accumulated dust while vibrating a protective cover.SOLUTION: A thermal head 23 having a plurality of heat generating elements on an upper portion thereof, a platen roller 31 provided so as to be movable between a pressure contact position where the platen roller 31 is brought into pressure contact with the thermal head 23 through intermediation of the thermal gauze and a separation position where the platen roller 31 is separated from the thermal head 23, the printer includes a protective cover 47 provided so as to move to a retracted position retracted to a side of a thermal head 23 in a substantially vertical state in conjunction with movement of a platen roller 31 to a press-contact position, and a holder 41 for guiding the protective cover 47 while being in contact with an inner wall so as to move to a protective position or the retracted position while being bent, and the inner wall of the holder 41 has a plurality of protrusions.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a platemaking device in which the printing surface of a TPH (Thermal Print Head) is positioned facing upward, and in particular to the mechanism that operates from the time the user places the screen frame facing the printing surface of the TPH until the platen roller clamps the screen section with the TPH, making it ready for platemaking. [Background technology]

[0002] Generally, screen printing machines that make screen plates by moving a gauze and a thermal head relative to each other and using the thermal head to heat and perforate the gauze are widely used because of their simple structure and easy plate-making process.

[0003] For example, Patent Document 1 discloses a technology relating to a screen platemaking device that moves a gauze frame, which is detachably mounted on the device housing and has a thermal gauze stretched over it, relative to a thermal head having multiple heating elements, and heats and perforates image data onto the thermal gauze using the multiple heating elements to create a perforated image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-1720 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the technology of Patent Document 1, the thermal head is installed above the thermal gauze with the heating elements facing downward. When the thermal gauze is installed below the thermal gauze, fine dust particles adhering to the gauze frame may fall onto the printing surface when the user installs the gauze frame. If a plate is made in this state, the fine dust particles may scratch the printing surface of the thermal head as the platen unit slides, damaging the conductors and heating elements of the thermal head and resulting in open dots.

[0006] Furthermore, if the thermal head is installed below the thermal gauze, the above-mentioned work will have already been completed just before plate making, and the printing surface of the thermal head will be covered by the thermal gauze, making it difficult to remove dust that has fallen onto the printing surface of the thermal head.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a plate-making device that, even when the thermal head is installed below the thermal gauze, removes accumulated dust by vibrating the protective cover after the gauze frame is installed. [Means for solving the problem]

[0008] In order to achieve the above object, a first feature of the plate making apparatus according to the present invention is to a gauze frame detachably mounted on the device housing and having a thermal gauze stretched thereon; a thermal head provided below the thermal gauze and having a plurality of heating elements on the upper part; a platen roller disposed above the thermal gauze and movable between a pressure contact position where the platen roller presses against the thermal head via the thermal gauze and a spaced position where the platen roller is spaced from the thermal head; a protective cover that moves to a protection position covering an upper portion of the thermal head in conjunction with the movement of the platen roller to the separated position, and moves to a retracted position in which the protective cover is retracted to a side of the thermal head so as to be in a substantially vertical state in conjunction with the movement of the platen roller to the pressure contact position; a holder that guides the protective cover while contacting an inner wall so that the protective cover moves to the protection position or the retracted position while bending the protective cover, The inner wall of the holder has a plurality of convex shapes at least at positions where the protective cover comes into contact with the inner wall and vibrates while moving to the retracted position. [Effects of the Invention]

[0009] In the plate making device according to the present invention, even if the thermal head is installed below the thermal gauze, the protective cover is in a protective position covering the top of the thermal head to catch dust while the gauze frame is being installed. After the gauze frame is installed, the protective cover is vibrated as it moves to the retracted position in conjunction with the operation of closing the head unit, thereby removing accumulated dust. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of an entire plate-making apparatus according to an embodiment of the present invention. [Figure 2] 1A to 1C are three-sided views of the periphery of a thermal head provided in a plate making apparatus according to one embodiment of the present invention. [Figure 3] 10A and 10B are explanatory views illustrating an operation when a head cover is opened in the plate making apparatus according to one embodiment of the present invention. [Figure 4] 10A and 10B are explanatory views illustrating an operation when closing a head cover in the plate making apparatus according to one embodiment of the present invention. [Figure 5] FIG. 2 is a state transition diagram of the plate making apparatus according to one embodiment of the present invention. [Figure 6] 4 is a flowchart showing the processing contents in the plate making apparatus according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are designated by the same or equivalent reference numerals throughout the drawings. However, it should be noted that the drawings are schematic and may differ from the actual product. Furthermore, the drawings may include parts with different dimensional relationships and ratios. Furthermore, the embodiments shown below are merely examples of devices and the like that embody the technical concept of this invention, and the technical concept of this invention does not limit the arrangement of each component to that shown below. Various modifications can be made to the technical concept of this invention within the scope of the claims.

[0012] FIG. 1 is an overall cross-sectional view of a plate making apparatus 10A according to one embodiment of the present invention, and FIG. 2 is a three-view diagram of the periphery of a thermal head 23 provided in the plate making apparatus according to one embodiment of the present invention.

[0013] As shown in FIGS. 1 and 2, an opening 11b is formed on the top surface 11a of the device housing 11 in a large rectangular shape.

[0014] A gauze frame 13 on which a heat-sensitive gauze 12 is stretched is positioned and detachably mounted above the opening 11b of the device housing 11.

[0015] In this case, the heat-sensitive gauze 12 is formed in a rectangular shape corresponding to a sheet of paper (not shown), such as A3 size paper, with a heat-melting film attached with an adhesive to a gauze having multiple meshes woven from warp and weft threads.

[0016] On the other hand, the gauze frame 13 is formed as a rectangular frame with a hollow interior, using a metal material such as aluminum that is rigid and has good thermal conductivity.

[0017] When the thermosensitive gauze 12 is attached to the gauze frame 13 with a predetermined tension applied, the heat-meltable film side of the thermosensitive gauze 12 is positioned on the lower side, facing the thermal head 23 described later, while the gauze side of the thermosensitive gauze 12 is positioned on the upper side, facing the platen roller 31 described later.

[0018] A head unit 20 is provided in the opening 11b of the device housing 11 so as to be reciprocable in the directions of arrows X1 and X2 along a pair of left and right guide rails 17L and 17R.

[0019] The head section 20 has a head cover 21 provided above each of the pair of left and right moving plates 18L, 18R so that it can be opened and closed around a platen rotation shaft 22. When the head cover 21 is opened, the gauze frame 13 on which the heat-sensitive gauze 12 is stretched can be detachably mounted inside the device housing 11.

[0020] A platen unit 30 is provided inside the head cover 21. In the platen unit 30, a platen roller 31 is supported rotatably about a rotation shaft 32 via a platen roller drive mechanism (not shown).

[0021] The platen roller 31 is rotatably fixed and supported in the head cover 21 so that when the head cover 21 is open, the platen roller 31 is in a spaced position away from the thermosensitive gauze 12, and when the head cover 21 is closed, the platen roller 31 is in a contact position in contact with the thermosensitive gauze 12.

[0022] On the other hand, a thermal head 23 is attached between the pair of left and right movable plates 18L, 18R so as to be movable integrally with both the movable plates 18L, 18R, and this thermal head 23 is provided below the heat-sensitive gauze 12 stretched on the gauze frame 13.

[0023] The thermal head 23 has a plurality of heating elements 23a arranged in a row at a predetermined pitch (e.g., 600 dpi) along the left-right direction, which is the main scanning direction, and this thermal head 23 has a head drive circuit 23b built in that selectively drives and heats the plurality of heating elements 23a.

[0024] Then, a plurality of heating elements 23 a provided in the thermal head 23 come into contact with the heat-meltable film of the heat-sensitive gauze 12 .

[0025] Furthermore, a control unit 40 is installed at an appropriate location within the apparatus housing 11, and serves as a control means for overall control of the plate making apparatus 10A of the first embodiment.

[0026] When the plate-making device 10A of the first embodiment is configured as described above, the pair of left and right movable plates 18L, 18R move to the top side, and the thermal head 23 and platen roller 31 wait together with both movable plates 18L, 18R at the HP (home position).

[0027] At this HP (home position), the head cover 21 of the head unit 20 is closed, so that the platen roller 31 is in contact with the thermal gauze 12.

[0028] After this, in response to a platemaking start command from the control unit 40, the thermal head 23 and the platen roller 31 are moved together with the pair of left and right moving plates 18L, 18R from the HP (home position) in the direction of arrow X1, which is the sub-scanning direction, and the platen roller 31 is pressed toward the thermal head 23 via the thermal gauze 12 by a pair of pressing spring mechanisms 34, 34.

[0029] A plurality of heating elements 23a provided in the thermal head 23 are selectively driven to heat in accordance with image data, and a perforation image is made on the heat-melting film of the thermosensitive gauze 12 by heat perforation.

[0030] As shown in FIGS. 2 to 4, plate making apparatus 10A according to one embodiment of the present invention includes protective cover 47 that covers thermal head 23 and holder 41 that guides protective cover 47 while bending it.

[0031] The protective cover 47 is arranged to move to a protective position covering the upper part of the thermal head 23 in conjunction with the movement of the platen roller 31 to the separated position, and to move to a retracted position retracted to the side of the thermal head 23 so as to be in a substantially vertical state in conjunction with the movement of the platen roller 31 to the pressure contact position.

[0032] The holder 41 guides the protective cover 47 while contacting the inner wall so that the protective cover 47 moves to the protection position or the retracted position while bending the protective cover 47. The inner wall of the holder 41 has a plurality of convex shapes 41a at least at positions where the protective cover 47 vibrates due to contact with the inner wall while moving to the retracted position.

[0033] In order to remove dust and the like adhering to the protective cover 47 by moving the protective cover 47, the cleaning device is provided with a coaxial gear 42, a clutch 43, a drive gear 44, a cleaning brush 45, a gear belt 46, belts 48, 53, gears 49, 51, and a fan gear 52.

[0034] When the head cover 21 is opened, the platen roller 31 moves to the separated position. At this time, the sector gear 52 rotates in the opening direction, as shown in Figure 3. In conjunction with this, the gear 51, the belt 53, and the gear 49 also rotate in the opening direction.

[0035] As a result, the protective cover 47, which is provided with the gear belt 46 in contact with the gear 49, moves in the opening direction. In this way, the protective cover 47 moves to the protection position where it covers the upper part of the thermal head 23 in conjunction with the movement of the platen roller 31 to the separated position.

[0036] On the other hand, when the head cover 21 is closed, the platen roller 31 moves to the pressure contact position. At this time, the sector gear 52 rotates in the closing direction, as shown in Figure 4. In conjunction with this, the gear 51, the belt 53, and the gear 49 also rotate in the closing direction.

[0037] As a result, the protective cover 47, which is provided with the gear belt 46 in contact with the gear 49, moves in the closing direction. In this way, the protective cover 47 moves to a retracted position where it is retracted to a position approximately perpendicular to the side of the thermal head 23 in conjunction with the movement of the platen roller 31 to the pressing position. Here, when the protective cover 47 moves to the retracted position, the cleaning brush 45 moves at a peripheral speed faster than the moving speed of the protective cover 47. This increases the effectiveness of the cleaning brush 45 in scraping off dust.

[0038] Since the inner wall of the holder 41 is provided with a plurality of convex shapes 41a, when the protective cover 47 moves to a retracted position so as to be substantially perpendicular to the side of the thermal head 23, the tip of the protective cover 47 comes into contact with the convex shapes 41a and moves to the retracted position while vibrating. This allows dust accumulated on the protective cover 47 to be removed.

[0039] FIG. 5 is a state transition diagram of a plate making apparatus 10A according to one embodiment of the present invention.

[0040] As shown in FIG. 5, in state ST11, which is the maintenance mode, the head cover 21 is open, the protective cover 47 is open, and the clutch 43 is off. When the power is turned on in this state and the state transitions to state ST12, an error message is issued (state ST13) because the head cover 21 is open.

[0041] When the head cover 21 is closed, the state shifts to state ST14, where the machine is in a normal standby state. When the master making is started, the state shifts to state ST15, where the master making is carried out.

[0042] Furthermore, when the head cover is opened in the normal standby state ST14, the state transitions to state ST16, in which the user removes and installs the screen frame.

[0043] When the power is turned off in the normal standby state ST14, the state transitions to state ST17.

[0044] FIG. 6 is a flowchart showing the processing performed by the plate making apparatus 10A according to one embodiment of the present invention.

[0045] In step S101, when an opening / closing sensor (not shown) detects that the head cover 21 is open, in step S103, the clutch 43 is turned off and the drive is released.

[0046] In step S105, since the head cover 21 is open, an error message is issued.

[0047] If the master presence / absence sensor (not shown) does not detect the gauze frame 13 (step S107; NO), the control unit 40 shifts to the maintenance mode (step S109).

[0048] On the other hand, if the master presence / absence sensor detects the gauze frame 13 (step S107; present), the control unit 40 waits until the head cover 21 is closed based on the detection result of the open / close sensor, and if the head cover 21 is closed (step S111; closed), initialization is performed in step S113.

[0049] In step S115, the control unit 40 turns on the clutch 43 to connect the drive. (Addendum)

[0050] The present application discloses the following inventions.

[0051] (Appendix 1) a gauze frame detachably mounted on the device housing and having a thermal gauze stretched thereon; a thermal head provided below the thermal gauze and having a plurality of heating elements on the upper part; a platen roller disposed above the thermal gauze and movable between a pressure contact position where the platen roller presses against the thermal head via the thermal gauze and a spaced position where the platen roller is spaced from the thermal head; a protective cover that moves to a protection position covering an upper portion of the thermal head in conjunction with the movement of the platen roller to the separated position, and moves to a retracted position in which the protective cover is retracted to a side of the thermal head so as to be in a substantially vertical state in conjunction with the movement of the platen roller to the pressure contact position; a holder that guides the protective cover while contacting an inner wall so that the protective cover moves to the protection position or the retracted position while bending the protective cover, The inner wall of the holder has a plurality of convex shapes at least at a position where the protective cover comes into contact with the inner wall and vibrates while moving to the retracted position. A plate-making apparatus characterized by:

[0052] Since the inner wall of the holder has multiple convex shapes, when the protective cover moves to a retracted position where it is retracted so that it is approximately perpendicular to the side of the thermal head, the tip of the protective cover comes into contact with the convex shapes and moves to the retracted position while vibrating. This vibration helps to remove dust that has accumulated on the protective cover. [Explanation of symbols]

[0053] 10A plate making device 11 Device housing 12 Heat-sensitive gauze 13 Gauze Frame 17L, 17R guide rail 18L,18R moving plate 20 Head 21 Headcover 23 Thermal head 23a Heating element 23b Head drive circuit 30 Platen 31 Platen roller 32 Rotation axis 34 Pressing spring mechanism 40 Control Unit 41 Holder 41a Convex shape 42 Coaxial Gear 43 Clutch 44 Drive gear 45 Cleaning Brush 46 Gear Belt 47 Protective Cover 48 Belt 49 gears 51 gears 52 Fan Gear 53 Belt

Claims

[Claim 1] a gauze frame detachably mounted on the device housing and having a thermal gauze stretched thereon; a thermal head provided below the thermal gauze and having a plurality of heating elements on the upper part; a platen roller disposed above the thermal gauze and movable between a pressure contact position where the platen roller presses against the thermal head via the thermal gauze and a spaced position where the platen roller is spaced from the thermal head; a protective cover that moves to a protection position covering an upper portion of the thermal head in conjunction with the movement of the platen roller to the separated position, and moves to a retracted position in which the protective cover is retracted to a side of the thermal head so as to be in a substantially vertical state in conjunction with the movement of the platen roller to the pressure contact position; a holder that guides the protective cover while contacting an inner wall so that the protective cover moves to the protection position or the retracted position while bending the protective cover, The inner wall of the holder has a plurality of convex shapes at least at a position where the protective cover comes into contact with the inner wall and vibrates while moving to the retracted position. A plate-making apparatus characterized by:

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