Conveyance object detection device

Abstract

To prevent dust from being determined as a sheet only by a single sensor.SOLUTION: A detection result storage part 51 stores a detection result that passing of a sheet PA has been detected by a detection part 41. A paper dust detection determination part 52, when the detection part 41 becomes a detection state, shifts to a dust detection state. The paper dust detection determination part 52, when the detection part 41 shifts from the detection state to a non-detection state, shifts to a dust detection suspending state. The paper dust detection determination part 52, when a detection result history of the detection result storage part 51 continues the non-detection state for a predetermined time, shifts to a dust non-detection state. A medium detection determination part 53, when the detection part becomes the detection state, shifts to a medium detection suspending state. The medium detection determination part 53, when the detection result history of the detection result storage part 51 continues the detection state for a predetermined time, shifts to a medium detection state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a transported object detection device that detects a transported sheet. [Background technology]

[0002] There is a line-type inkjet recording apparatus that performs printing by ejecting ink onto paper being transported. In the line-type inkjet recording apparatus, a sensor or the like is used to detect the paper being transported to monitor the transport state of the paper.

[0003] At this time, dust particles such as paper powder or dirt may cause the sensor to react incorrectly, leading to the printing device mistaking the reaction for paper, causing the printing device to stop at an unintended time.

[0004] Patent document 1 discloses a printing device equipped with a transmissive sensor and a reflective sensor that detect the edges of the printing medium while it is being transported, and a printing medium determination unit that determines the position of the printing medium based on printing medium detection information obtained by the transmissive sensor and the reflective sensor, and the amount of transportation of the printing medium between when the reflective sensor detects the printing medium and when the transmissive sensor detects the printing medium. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-261721 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, while the technology described in Patent Document 1 discloses a method for improving the detection accuracy of the print medium by using multiple detection means, the detection units themselves are costly and require installation space, making it difficult to adopt this method for all detection units of a printing device.

[0007] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a transported object detection device that prevents dust from being determined to be paper using only a single sensor. [Means for solving the problem]

[0008] In order to achieve the above object, the transported object detection device according to the present invention is characterized by: The device includes a transport unit that transports a medium, a detection unit that detects that the medium transported by the transport unit has passed through, a detection result storage unit that stores the detection result of the detection unit as a history, a dust detection determination unit, and a medium detection determination unit, When the detection unit is in a detection state, the dust detection determination unit transitions to a dust detection state, and the medium detection determination unit transitions to a medium detection pending state; When the detection unit changes from the detection state to a non-detection state, the dust detection determination unit transitions to a dust detection pending state, When the detection result history of the detection result storage unit continues a non-detection state for a predetermined period of time, the dust detection determination unit transitions to a dust non-detection state, When the detection result history of the detection result storage unit continues a detection state for a predetermined period of time, the medium detection determination unit transitions to a medium detection state. The point is... Effect of the Invention

[0009] According to the feature of the transported object detection device of the present invention, it is possible to prevent dust from being determined to be paper by using only a single sensor. [Brief description of the drawings]

[0010] [Figure 1] 1 is a configuration diagram of an inkjet printing apparatus according to an embodiment of the present invention. [Diagram 2] 5 is a state transition diagram showing state transitions caused by a paper dust detection determination unit included in the inkjet printing apparatus according to the embodiment of the present invention. FIG. [Diagram 3] 5 is a timing chart showing paper dust detection by a paper dust detection determination unit included in the inkjet printing apparatus according to the embodiment of the present invention. [Figure 4] 5 is a state transition diagram showing state transitions caused by a medium detection determination unit included in the inkjet printing apparatus according to the embodiment of the present invention. FIG. [Diagram 5] 5 is a timing chart showing medium detection by a medium detection determination unit included in the inkjet printing apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment 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. In addition, the drawings may include parts with different dimensional relationships and ratios.

[0012] The embodiments described below are merely examples of devices for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the arrangement of each component part as described below. Various modifications can be made to the technical idea of ​​the present invention within the scope of the claims.

[0013] <Configuration of Inkjet Printing Device 1> DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an inkjet printing apparatus 1 to which a transported object detection device according to the present invention is applied will be described in detail below with reference to the accompanying drawings.

[0014] FIG. 1 is a diagram showing the configuration of an inkjet printing apparatus 1 according to an embodiment of the present invention.

[0015] As shown in FIG. 1, the inkjet printing apparatus 1 includes a suction transport unit 2, a printing unit 3, a transported object detection unit 4, and a control unit 5.

[0016] The suction conveyance unit 2 conveys the paper PA conveyed from a paper feed unit (not shown) toward the printing unit 3 and the conveyed object detection unit 4. The suction conveyance unit 2 includes a conveyor belt 21, a drive roller 22, and driven rollers 23-25.

[0017] The conveyor belt 21 is a circular endless belt stretched around a drive roller 22 and driven rollers 23 to 25. The conveyor belt 21 has intake holes, which are through holes for attracting and holding the paper sheet PA, formed at predetermined intervals along the conveying direction of the conveyor belt 21. The conveyor belt 21 attracts and holds the paper sheet PA on the conveyor belt 21 by a negative pressure (adsorption force) generated in the intake holes by driving a suction fan (not shown).

[0018] 1 by being rotated by the driving roller 22. As a result, the conveyor belt 21 moves endlessly to convey the paper PA to the right.

[0019] The drive roller 22 and the driven rollers 23 to 25 are disposed around which the conveyor belt 21 is stretched. The drive roller 22 is rotated by a belt drive motor to rotate the conveyor belt 21. The driven rollers 23 to 25 are driven by the drive roller 22 via the conveyor belt 21. The driven roller 23 is disposed at substantially the same height as the drive roller 22 and spaced a predetermined distance from the drive roller 22 in the left-right direction. The driven rollers 24 and 25 are disposed below the drive roller 22 and the driven roller 23, spaced a predetermined distance from each other in the left-right direction, and at substantially the same height.

[0020] The printing unit 3 prints on the paper PA transported by the suction transport unit 2. The printing unit 3 is provided above the suction transport unit 2. The printing unit 3 is fixed inside a housing (not shown) of the inkjet printing device 1. The printing unit 3 is equipped with inkjet heads for black (K), cyan (C), magenta (M) and yellow (Y).

[0021] The inkjet head has multiple nozzles at the bottom, and prints by ejecting ink from the nozzles onto the paper PA that is transported while being sucked by the suction transport unit 2. The nozzles form a nozzle row that is linearly arranged in the left-right direction (main scanning direction).

[0022] The conveyed object detection unit 4 detects the printed paper PA conveyed by the conveyor belt 21 while conveying the paper PA. The conveyed object detection unit 4 includes a conveyor belt 41, a drive roller 42, and a driven roller 43.

[0023] 1 by the rotational drive of the drive roller 42. As a result, the conveyor belt 41 moves endlessly to convey the paper PA to the right.

[0024] The conveyor belt 41 is stretched around the drive roller 42 and the driven roller 43. The drive roller 42 is rotated by a belt drive motor to rotate the conveyor belt 41. The driven roller 43 is driven by the drive roller 42 via the conveyor belt 41. The driven roller 43 is disposed at approximately the same height as the drive roller 42 and spaced a predetermined distance from the drive roller 42 in the left-right direction.

[0025] The detection unit 41 has an optical sensor and detects that the paper PA transported by the transport belt 41 has passed through it.

[0026] The control unit 5 is configured with, for example, a CPU, RAM, ROM, hard disk, etc., and executes printing processing by controlling the operations of the suction and conveyance unit 2, the printing unit 3, and the conveyed object detection unit 4. The control unit 5 functionally has a detection result storage unit 51, a paper dust detection judgment unit 52, and a medium detection judgment unit 53.

[0027] The detection result storage unit 51 stores the detection result of the detection unit 41 detecting that the sheet PA has passed through.

[0028] The paper dust detection determination unit 52 transitions to a dust detection state when the detection unit 41 enters a detection state. Also, the paper dust detection determination unit 52 transitions to a dust detection pending state when the detection unit 41 goes from a detection state to a non-detection state. Also, the paper dust detection determination unit 52 transitions to a dust non-detection state when the detection result history in the detection result storage unit 51 continues to show a non-detection state for a predetermined period of time.

[0029] The medium detection determination unit 53 transitions to a medium detection pending state when the detection unit enters a detection state. Also, the medium detection determination unit 53 transitions to a medium detection state when the detection result history in the detection result storage unit 51 indicates that the detection state has continued for a predetermined period of time.

[0030] 2 is a state transition diagram showing state transitions by the paper dust detection determination unit 52 included in the inkjet printing apparatus 1 according to the embodiment of the present invention. Here, the dust will be described as paper dust, but dust or pieces (dirt) other than paper dust that may cause the sensor of the detection unit 41 to make a false detection may also be used.

[0031] 2, when the detection unit 41 enters a detection state in the non-detection state of state S101, the state transitions to state S103, which is a dust detection state. When the detection unit 41 enters a non-detection state from the detection state, the state transitions to state S105, which is a dust detection pending state.

[0032] The state transitions to state S105, and if the non-detection state does not continue for a predetermined period of time based on the detection result history stored in the detection result memory unit 51, the state transitions to state S107, and the paper dust detection judgment unit 52 counts the paper dust detections.

[0033] On the other hand, if the state transitions to state S105 and the non-detection state continues for a predetermined period of time based on the detection result history stored in the detection result memory unit 51, the state transitions from state S109, which is a fixed non-detection state, to state S109, which is a fixed non-detection state, and then transitions to state S101.

[0034] FIG. 3 is a timing chart showing paper dust detection by the paper dust detection determination unit 52 included in the inkjet printing apparatus 1 according to the embodiment of the present invention.

[0035] 3, at time t1, the detection unit 41 goes into a detection state, but immediately thereafter goes into a non-detection state, and therefore, at time t1, the state transitions to a dust detection pending state.

[0036] Then, at time t3, the paper dust detection judgment unit 52 judges that the detection result history in the detection result memory unit 51 has continued the non-detection state for a predetermined period of time, and the paper dust detection transitions to a non-detection state, i.e., a dust non-detection state.

[0037] 4 is a state transition diagram showing state transitions by the medium detection determination unit 53 included in the inkjet printing apparatus 1 according to the embodiment of the present invention. Here, the medium is described as paper PA, but is not limited to this and may be any sheet-like medium.

[0038] As shown in FIG. 4, when the detection unit 41 enters a detection state in the non-detection state of state S201, the state transitions to state S203, which is a medium detection pending state.

[0039] Furthermore, if the detection result history in the detection result storage unit 51 indicates that the detection state has continued for a predetermined period of time, the state transitions to state S205, which is a medium detection state.

[0040] Furthermore, if the detection unit 41 goes into a non-detection state during the medium detection state of state S205, the state transitions to state S203, which is a medium detection pending state.

[0041] Then, when the detection result history in the detection result storage unit 51 indicates that the non-detection state continues for a predetermined period of time, the state transitions to state S201, which is the non-detection state.

[0042] FIG. 5 is a timing chart showing medium detection by the medium detection determination unit 53 included in the inkjet printing apparatus 1 according to the embodiment of the present invention.

[0043] As shown in FIG. 5, at time t11, the detection unit 41 goes into a detecting state, and medium detection transitions to a detection pending state, that is, a medium detection pending state.

[0044] At time t13, the medium detection determiner 53 determines that the detection result history in the detection result storage unit 51 indicates that the detection state has continued for a predetermined time, and the medium detection state transitions to a detection state, that is, a medium detection state.

[0045] At time t15, the detection unit 41 goes into a non-detection state, and medium detection transitions to a detection pending state, that is, a medium detection pending state.

[0046] At time t17, the medium detection determiner 53 determines that the detection result history in the detection result storage unit 51 indicates that the non-detection state has continued for a predetermined time, and the medium detection transitions to a non-detection state.

[0047] (Additional Note) This application discloses the following inventions.

[0048] (Appendix 1) The device includes a transport unit that transports a medium, a detection unit that detects that the medium transported by the transport unit has passed through, a detection result storage unit that stores the detection result of the detection unit as a history, a dust detection determination unit, and a medium detection determination unit, When the detection unit is in a detection state, the dust detection determination unit transitions to a dust detection state, and the medium detection determination unit transitions to a medium detection pending state; When the detection unit changes from the detection state to a non-detection state, the dust detection determination unit transitions to a dust detection pending state, When the detection result history of the detection result storage unit continues a non-detection state for a predetermined period of time, the dust detection determination unit transitions to a dust non-detection state, When the detection result history of the detection result storage unit continues a detection state for a predetermined period of time, the medium detection determination unit transitions to a medium detection state. A transported object detection device.

[0049] This allows the sensor to distinguish between paper dust or debris if the detection unit continues to detect nothing during the pending state, and paper if the detection unit continues to detect something during the pending state, by temporarily inserting a "pending state" such as dust detection pending state or media detection pending state. This makes it possible to prevent dust from being identified as paper by a single sensor alone. [Explanation of symbols]

[0050] 1 Inkjet printing device 2. Suction and transport section 3 Printing Department 4. Transported object detection section 5. Control section 41 Detection unit 41 Conveyor belt 42 Drive roller 43 Driven roller 51 Detection result storage unit 52 Paper dust detection and judgment unit 53 Media detection judgement unit

Claims

[Claim 1] The device includes a transport unit that transports a medium, a detection unit that detects that the medium transported by the transport unit has passed through, a detection result storage unit that stores the detection result of the detection unit as a history, a dust detection determination unit, and a medium detection determination unit, When the detection unit is in a detection state, the dust detection determination unit transitions to a dust detection state, and the medium detection determination unit transitions to a medium detection pending state; When the detection unit changes from the detection state to a non-detection state, the dust detection determination unit transitions to a dust detection pending state, When the detection result history of the detection result storage unit continues a non-detection state for a predetermined period of time, the dust detection determination unit transitions to a dust non-detection state, When the detection result history of the detection result storage unit continues a detection state for a predetermined period of time, the medium detection determination unit transitions to a medium detection state. A transported object detection device.

Images