JP2008238797A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an image of good precision on a thick paper, in an image forming device with an inexpensive structure. <P>SOLUTION: The image forming device is constituted of a paper feed tray 2 for holding a thick paper P, a transfer mechanism 3 for transferring the thick paper P held in the paper feed tray 2, an image forming part 4 for forming an image on the thick paper P, a lift motor 8 for vertically moving a platen 34 supporting the thick paper P in transfer, an infrared sensor 7 and a control unit 9 or the like for controlling each part. The infrared sensor 7 outputs to the control unit 9 the time taken after infrared light is irradiated onto the thick paper P held in the paper feed tray 2 until the infrared light reflected from the thick paper P is received. When an image is formed on the thick paper P, the control unit 9 uses the time output from the infrared sensor 7 to measure the thickness of the thick paper P, driving the lift motor 8 based on the thickness of the paper P to vertically move the platen 34 so that the distance between the print head 43 in the image forming position and the thick paper 43 comes within a fixed range. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of forming an accurate image on a thick paper.

  In recent years, an ink jet type image forming apparatus (hereinafter referred to as an ink jet printer) that forms an image on recording paper by applying ink droplets from a print head has been widely used. The inkjet printer includes a paper feed tray that holds recording paper, a paper feed roller that transports the recording paper to a position facing the print head, and a paper discharge roller that transports the recording paper on which an image is formed downstream. . A paper feed roller is provided on the upstream side of the print head and a paper discharge roller is provided on the downstream side along the recording paper conveyance direction.

The recording paper is conveyed to a position facing the print head by a paper feed roller. After an image is formed on the recording paper by the print head, the recording paper is conveyed downstream by a paper discharge roller. In this type of ink jet printer, in order to maintain the accuracy of the image formed on the recording paper, the distance between the print head and the recording paper at the image forming position must be kept within a certain range. For this reason, this type of ink jet printer cannot maintain the distance between the print head and the thick paper within a certain range when an image is formed on a recording paper having a predetermined thickness or more (hereinafter, thick paper). In some cases, an image with high accuracy cannot be formed.
JP 2006-103949 A JP 2004-202704 A

  On the other hand, Patent Document 1 discloses an ink jet printer including a paper feed tray that can move up and down. However, in this ink jet printer, the paper feed tray cannot be moved up and down based on the thickness of the cardboard, so the distance between the print head and the cardboard cannot be kept within a certain range, and the accuracy of the ink jet printer on the cardboard is high. A good image may not be formed.

  Patent Document 2 discloses an ink jet printer that includes a thickness measurement sensor that measures the thickness of a cardboard and a print head that can move up and down based on the thickness of the cardboard detected by the thickness measurement sensor. However, in this ink jet printer, it is necessary to move the print head up and down and to reciprocate the print head in a direction perpendicular to the transport direction of the cardboard, so a complicated mechanism is required, and the manufacturing cost of the ink jet printer cannot be suppressed. There is a problem.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can form an accurate image on cardboard with an inexpensive configuration.

  In order to achieve the above object, the invention of claim 1 includes a paper feed tray that holds thick paper having a thickness of 1 to 3 mm, first transport means for transporting the thick paper held in the paper feed tray into the apparatus, An image forming unit that forms an image on the cardboard transported by the first transport unit, a second transport unit that transports the cardboard on which the image is formed by the image forming unit to the outside of the apparatus, and a transport by the second transport unit A paper discharge tray on which the used thick paper is deposited, a platen that supports the thick paper transported into the apparatus by the first transport means, driving means for driving the first transport means and the second transport means, and the first And a control unit for controlling the driving unit. The image forming unit includes an ink cartridge filled with ink, and the ink cartridge is mounted to transport the cardboard. A carrier that reciprocates in a direction perpendicular to the direction and a carrier driving unit that drives the carrier, and forms an image by applying ink droplets on the cardboard transported by the first transport unit; The first transport unit includes a pick roller that feeds the thick paper held in the paper feed tray to the inside of the apparatus, and a paper feed roller that transports the thick paper sent by the pick roller to an image forming position by the image forming unit. And the second transport means radiates infrared rays to the thick paper held in the paper feed tray in an image forming apparatus having a paper discharge roller for transporting the thick paper on which the image is formed to the downstream side. And an infrared sensor that outputs a time until the infrared light reflected from the cardboard is received; and a lift motor that moves the platen up and down. The paper feeding roller, the paper discharge roller, and the driving unit are connected to the platen, and the control unit further controls the lift motor based on the output of the infrared sensor to form an image on the cardboard. Then, using the output of the infrared sensor, the thickness of the thick paper held in the paper feed tray is measured, and the lift motor is driven based on the measured thickness to drive the image forming means and the thick paper at the image forming position. The platen is moved up and down so that the distance between the platen and the sheet is within a certain range, and then the drive unit is controlled to transport the cardboard inside the apparatus, and the image forming unit forms an image on the cardboard. Thus, it is possible to form an accurate image on a cardboard.

  According to a second aspect of the present invention, a first transport unit that transports cardboard into the apparatus, an image forming unit that forms an image on the cardboard transported by the first transport unit, and an image is formed by the image forming unit. Controls each part of the apparatus, a second conveying means for conveying the cardboard to the outside of the apparatus, a conveying path for supporting the cardboard conveyed inside the apparatus, a driving means for driving the first conveying means and the second conveying means, and the like. Control means, and the image forming means forms an image by applying ink droplets on the cardboard transported by the first transporting means, and the first transporting means forms an image on the cardboard by the image forming means. The second conveying means measures and outputs the thickness of the thick paper in an image forming apparatus having a paper discharge roller that conveys the thick paper on which the image is formed to the downstream side. Thickness measurement sensor And a lift motor that moves the transport path up and down, wherein the paper feed roller, the paper discharge roller, and the driving unit are connected to the transport path, and the control unit forms an image on the cardboard. When the lift motor is driven based on the output of the thickness measurement sensor to move the transport path up and down, the drive means is controlled to transport the cardboard inside the apparatus.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the image forming apparatus further includes a paper feed tray that holds cardboard, and the first transport unit transports the cardboard held in the paper feed tray into the apparatus. The transport path is further connected to the paper feed tray.

  According to the invention of claim 1, the control means drives the lift motor based on the measured thickness to move the platen up and down so that the distance between the image forming means and the cardboard at the image forming position is within a certain range. After that, the thick paper is conveyed inside the apparatus, and an image is formed on the thick paper by the image forming means. Therefore, an accurate image can be formed on the cardboard. Compared with the configuration in which the print head is moved up and down as described in Patent Document 2, it is only necessary to move the platen up and down, the structure is simple, and the manufacturing cost of the image forming apparatus is suppressed. Can do.

  According to the second aspect of the present invention, the control means drives the lift motor based on the output of the thickness measurement sensor to move the transport path up and down, and then controls the drive means to transport the cardboard inside the apparatus. For this reason, the distance between the image forming means and the cardboard at the image forming position can be within a certain range, so that an accurate image can be formed on the cardboard. Further, as compared with the configuration in which the print head is moved up and down as described in Patent Document 2, it is only necessary to move the plate running path in the vertical direction, the structure is simple, and the manufacturing cost of the image forming apparatus is suppressed. be able to.

  According to the invention of claim 3, the same effect as that of the invention of claim 2 can be obtained.

  Hereinafter, an ink jet printer as an example of an image forming apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an ink jet printer. The ink jet printer 1 includes a paper feed tray 2 that holds cardboard or drawing paper having a thickness of about 1 to 3 mm, a transport mechanism 3 that transports the thick paper P held in the paper feed tray 2, and this transport An image forming unit (image forming unit) 4 that forms an image on the thick paper P transported by the mechanism 3, a paper discharge tray 5 on which the thick paper P on which an image is formed by the image forming unit 4, and the transport mechanism 3 and A lift motor 8 that moves up and down a casing 6 that accommodates the image forming unit 4, an infrared sensor (thickness measurement sensor) 7 that emits and receives infrared rays, and a platen (conveyance path) 34 that supports the cardboard P being conveyed. And a control unit (control means) 9 for controlling the transport mechanism 3, the image forming unit 4, and the lift motor 8.

  In the transport mechanism 3, an image is formed by the first transport mechanism (first transport unit) 3 a that transports the thick paper P held on the paper feed tray 2 to an image forming position by the image forming unit 4 and the image forming unit 4. A second transport mechanism (second transport means) 3b that transports the thick paper P to the paper discharge tray 5, a platen 34 that supports the thick paper P transported into the housing 6 by the first transport mechanism 3a, and a first transport mechanism 3a and a feed motor (driving means) 30 for driving the second transport mechanism 3b. The thick paper P is held by the platen 34 when positioned at the image forming position.

  The image forming unit 4 includes an ink cartridge 40 filled with ink, a carrier 41 that reciprocates in the main scanning direction orthogonal to the transport direction A (sub-scanning direction) of the thick paper P while supporting the ink cartridge 40, and the carrier A carrier driving motor (carrier driving means) 42 for driving 41 is configured.

  On the lower surface of the ink cartridge 40, a print head 43 for ejecting ink onto the thick paper P is provided. The carrier 41 is supported by a shaft 44 disposed in parallel to the main scanning direction so as to be reciprocally movable, and is driven by the carrier drive motor 42 to move. The output of the carrier drive motor 42 is transmitted to the carrier 41 via a belt or the like. The carrier 41 is ejected from the print head 43 in synchronization with the drive of the feed motor 30 and the carrier drive motor 42 under the control of the control unit 9, and thereby onto the cardboard P that is transported by the first transport mechanism 3 a. An image is formed by applying ink droplets. When forming an image by applying ink droplets, that is, when the thick paper P is positioned at the image forming position, if the distance between the print head 43 and the thick paper P is not within a certain range, a highly accurate image on the thick paper P Can not form.

  The infrared sensor 7 is provided above the opening 6 a for carrying the thick paper P held in the paper feed tray 2 into the housing 6, and receives infrared radiation and reflected light. The infrared sensor 7 emits infrared rays to the thick paper P held on the paper feed tray 2 and then outputs to the control unit 9 the time until the infrared light reflected from the thick paper P is received. The controller 9 measures the thickness of the thick paper P held on the paper feed tray 2 based on the time output from the infrared sensor 7, and drives and controls the lift motor 8 based on the measured thickness.

  FIG. 2 shows a schematic configuration of the first transport mechanism 3 a, the second transport mechanism 3 b, the feed motor 30, and the lift motor 8. The first transport mechanism 3 a is provided on the upstream side of the print roller 43 and a pick roller 31 (see FIG. 1) that sends the thick paper P held in the paper feed tray 2 into the housing 6, and is sent by the pick roller 31. The thick paper P is composed of a paper feed roller 32 that sends the thick paper P to the downstream side of the print head 43, a pressure roller 33 that presses the recording paper P against the paper feed roller 32, and the like. The second transport mechanism 3b includes a paper discharge roller 38 that transports the thick paper P on which an image is formed to the paper discharge tray 5, a star wheel 39 that presses the thick paper P against the paper discharge roller 38, and the like.

  The paper feed roller 32, the paper discharge roller 38, and the feed motor 30 are connected to the platen 34, and when the platen 34 is moved up and down by the lift motor 8, the paper feed roller 32, the paper discharge roller 38, and the feed motor 30 is moved up and down similarly to the platen 34.

  When forming an image on the thick paper P, the control unit 9 measures the thickness of the thick paper P held on the paper feed tray 2 by using the time output from the infrared sensor 7. Then, the lift motor 8 is driven based on the measured thickness of the thick paper P, the platen 34 is moved up and down so that the distance between the print head 43 and the thick paper P at the image forming position is within a certain range, and then the feed is performed. The motor 30 is controlled to transport the cardboard P into the housing 6. Then, the print head 43 applies ink on the thick paper P to form an image.

  As described above, according to the ink jet printer 1 according to the present embodiment, the control unit 9 moves the platen 34 up and down based on the thickness of the thick paper P, whereby the print head 43 and the thick paper P at the image forming position are moved. The distance can be within a certain range. Then, the image forming unit 4 forms an image on the thick paper P. Therefore, an accurate image can be formed on the thick paper P. Compared to a configuration in which the print head is moved up and down like a conventional ink jet printer, the ink jet printer 1 according to the present embodiment only needs to move the platen 34 in the up and down direction, and has a simple structure. The manufacturing cost can be suppressed.

  Next, an ink jet which is an example of an image forming apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 shows a schematic configuration of the ink jet printer 1. In FIG. 3, members denoted by the same reference numerals indicate the same members as those in the first embodiment, and description thereof is omitted.

  The inkjet printer 1 of the second embodiment is the same as that of the first embodiment except that the paper feed roller 32, the paper discharge roller 38, the feed motor 30, and the paper feed tray 2 are connected to the platen 34. The configuration is the same as that of the inkjet printer 1.

  When the platen 34 is moved up and down by the lift motor 8, the paper feed roller 32, the paper discharge roller 38, the feed motor 30 and the paper feed tray 2 are also moved up and down in the same manner as the platen 34. Therefore, when the controller 9 forms an image on the thick paper P, the distance between the print head 43 and the thick paper P at the image forming position is within a certain range based on the thickness of the thick paper P held on the paper feed tray 2. The platen 34 can be moved up and down so that

  As described above, according to the ink jet printer 1 according to the present embodiment, the same effects as those of the ink jet printer 1 according to the first embodiment can be obtained.

  The present invention is not limited to the configuration of each of the above embodiments. For example, the infrared sensor 7 is used to measure the thickness of the thick paper P held on the paper feed tray 2, but the present invention is not limited to this. A distance measuring mechanism for extending the measuring rod toward the thick paper P held in the paper feeding tray 2 is provided above the paper tray 2, and the length until the extended measuring rod hits the thick paper P is measured to thereby feed the paper. The thickness of the cardboard P held on the tray 2 may be measured.

  In the inkjet printer 1 according to each of the embodiments described above, an example in which an image is formed on the thick paper P having a thickness of about 1 to 3 mm is shown, but the present invention is not limited thereto, and an arbitrary thickness of 1 mm or less and 3 mm or more. An image may be formed on the thick paper.

1 is a diagram illustrating a configuration of an ink jet printer that is an example of an image forming apparatus according to a first embodiment of the present invention. FIG. FIG. 2 is a side view illustrating a schematic configuration of a transport mechanism and a lift motor of the printer. FIG. 6 is a diagram illustrating a configuration of an ink jet printer that is an example of an image forming apparatus according to a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Paper feed tray 3 Conveyance mechanism 3a First conveyance mechanism (first conveyance means)
3b Second transport mechanism (second transport means)
4 Image forming unit (image forming means)
5 Discharge tray 6 Case 7 Infrared sensor (thickness measurement sensor)
8 Lift motor 9 Control unit (control means)
30 Feed motor (drive means)
31 Pick roller 32 Paper feed roller 33 Press roller 34 Platen (conveyance path)
38 Paper discharge roller 39 Star wheel 40 Ink cartridge 41 Carrier 42 Carrier drive motor (carrier drive means)
43 Printhead

Claims (3)

An image is formed on the paper feed tray that holds the thick paper having a thickness of 1 to 3 mm, the first transport means that transports the thick paper held in the paper feed tray into the apparatus, and the thick paper transported by the first transport means. Image forming means, second transport means for transporting the cardboard on which the image is formed by the image forming means to the outside of the apparatus, a paper discharge tray on which the thick paper transported by the second transport means is deposited, A platen that supports the cardboard conveyed inside the apparatus by the conveying means, a driving means for driving the first conveying means and the second conveying means, the first conveying means, the second conveying means, and the driving means Control means for controlling
The image forming unit includes an ink cartridge filled with ink, a carrier in which the ink cartridge is mounted and reciprocating in a direction perpendicular to the transport direction of the cardboard, and a carrier driving unit that drives the carrier. And applying ink droplets on the cardboard transported by the first transport means to form an image,
The first transport unit includes a pick roller that feeds the thick paper held in the paper feed tray to the inside of the apparatus, and a paper feed roller that transports the thick paper sent by the pick roller to an image forming position by the image forming unit. And
In the image forming apparatus, the second conveying unit includes a discharge roller that conveys the cardboard on which the image is formed to the downstream side.
An infrared sensor that outputs the time until the infrared light reflected from the thick paper is received after radiating infrared light to the thick paper held in the paper feed tray;
A lift motor that moves the platen up and down;
The paper feed tray, the paper feed roller, the paper discharge roller, and the driving means are coupled to the platen,
The control means includes
Further controlling the lift motor based on the output of the infrared sensor;
When forming an image on cardboard, the output of the infrared sensor is used to measure the thickness of the cardboard held in the paper feed tray, and the lift motor is driven based on the measured thickness to form an image formation position. The platen is moved up and down so that the distance between the image forming unit and the cardboard is within a certain range, and then the driving unit is controlled to transport the cardboard inside the apparatus, and the image forming unit places the cardboard on the cardboard. An image forming apparatus, wherein an image can be formed on a cardboard with high accuracy by forming an image. A first conveying unit that conveys the cardboard into the apparatus, an image forming unit that forms an image on the thick sheet conveyed by the first conveying unit, and a cardboard on which an image is formed by the image forming unit is conveyed outside the apparatus. A second conveying means, a conveying path for supporting the cardboard conveyed inside the apparatus, a driving means for driving the first conveying means and the second conveying means, and a control means for controlling each part of the apparatus,
The image forming unit forms an image by applying ink droplets on a cardboard transported by the first transport unit;
The first transport unit includes a paper feed roller that transports thick paper to an image forming position by the image forming unit,
In the image forming apparatus, the second conveying unit includes a discharge roller that conveys the cardboard on which the image is formed to the downstream side.
A thickness measurement sensor that measures and outputs the thickness of the cardboard;
A lift motor that moves the transport path up and down;
The paper feed roller, the paper discharge roller, and the driving means are coupled to the transport path,
When forming an image on cardboard, the control unit drives the lift motor based on the output of the thickness measurement sensor to move the transport path up and down, and then controls the drive unit to control the inside of the apparatus. An image forming apparatus for transporting cardboard. A paper tray that holds cardboard
The first transport means transports the cardboard held in the paper feed tray into the apparatus,
The image forming apparatus according to claim 2, wherein the conveyance path is further connected to the paper feed tray.

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