JP4817878B2 - Recording device - Google Patents

Description

  The present invention relates to a recording apparatus that records an image on a recording sheet with a recording head based on image information, and more particularly to a recording apparatus that includes guide means having a suction port at a position facing the recording head.

  A recording apparatus having a function such as a printer, a copying machine, or a facsimile uses a recording head based on image information to print an image (characters, symbols, etc.) on a recording medium made of a sheet material such as paper, cloth, a plastic sheet, and an OHP sheet. Are included). Also, various types of recording apparatuses have been proposed as means for printing image information from a personal computer or digital camera. There are a serial type and a line type as a recording method in the recording apparatus. The serial type is a system in which an image is recorded while alternately repeating main scanning for moving the recording head along the sheet material and sub-scanning for feeding the sheet material at a predetermined pitch. The line type is a method in which an image is recorded only by sheet feeding (sub-scanning) of a sheet material while recording one line at a time. The recording apparatus can be classified into an ink jet type, a thermal transfer type, a laser beam type, a thermal type, a wire dot type, and the like depending on the recording method.

  In the recording apparatus, a platen serving as guide means for guiding and supporting the recording sheet at a position facing the recording head is provided. The recording sheet supplied into the apparatus is conveyed to the recording start position on the platen by the conveying roller, and from there, image recording is performed on the entire recording sheet while repeating the recording operation by the recording head and the paper feeding by the conveying roller. On the downstream side of the platen conveyance, a paper discharge roller that is driven in synchronization with the conveyance roller is disposed. The recorded recording sheet is conveyed by the conveyance roller and the paper discharge roller and finally discharged from the apparatus main body by the paper discharge roller. In a recording apparatus, in order to maintain good image recording quality, it is required to maintain the recording sheet on the platen at a certain position and posture with respect to the recording head. This is strictly required in an ink jet recording apparatus that records by ejecting ink droplets from opposing recording heads at a certain distance compared to other recording apparatuses.

  For this purpose, it is necessary to prevent the recording sheet from floating from the platen surface when passing over the platen. Further, it is necessary to convey the recording head (for example, an ink ejection surface in the case of inkjet recording) and the recording sheet while keeping the distance between them constant. For example, in a recording apparatus that uses roll paper as the recording sheet, it is necessary to prevent the distance between the recording head and the recording sheet from becoming uneven due to curling at the leading edge of the roll paper. In order to cope with such a problem, a technique is adopted in which a suction portion for sucking the recording sheet is provided on the upper surface (platen surface) of the platen which is a guide means for guiding and supporting the recording sheet. This suction part is usually composed of a plurality of suction ports formed on the platen surface and a fan for sucking outside air from each suction port.

  In such a configuration in which a plurality of suction ports are provided in order to suck the recording sheet to the platen surface, there is a problem that the suction ability is lowered when the leading edge of the recording sheet passes over the platen. When the leading edge of the recording sheet passes, it is covered with the leading edge of the recording sheet in order from the suction opening on the upstream side in the conveying direction among the plurality of suction openings arranged in the conveying direction (sub-scanning direction). That is, while the leading edge of the recording sheet is conveyed, the suction operation is performed in a state where the suction port near the paper discharge side is not yet covered with the recording sheet. For this reason, compared with the state in which the entire suction port is covered with the recording sheet, the suction capability is lowered. Accordingly, it becomes difficult to keep the distance between the recording head and the recording sheet appropriate, for example, it is difficult to correct the curl shape at the tip. Furthermore, there is a problem that noise is generated by the passage of outside air through a suction port that is not covered with a recording sheet, and noise is increased.

As means for solving such a problem, the recording port is configured such that the suction port is closed when the leading edge of the recording sheet has not been conveyed, and the suction port is sequentially opened according to the conveyance of the leading edge when the recording sheet has been conveyed. The apparatus is disclosed in FIG.
JP 2002-205855 A

  However, the conventional example disclosed in Patent Document 1 has the following problems. That is, in the conventional example, the suction port is sequentially opened in the transport direction, but no consideration is given to the recording sheet width direction. In general, the recording apparatus can record on recording sheets having different widths such as A2 width and A4 width. In a recording apparatus having a suction port on a platen, the suction port is arranged up to a position corresponding to the maximum width so that a recording sheet having the maximum width can be sucked to the platen. In such a configuration, for example, when recording is performed on a recording sheet having an A4 width in a recording apparatus in which the suction port is disposed up to a position corresponding to the A2 width, suction is also performed from the suction port that does not cover the recording sheet. For this reason, compared with the case where all the suction ports are covered with the recording sheet, there arises a disadvantage that wasteful energy consumption occurs and the suction ability is lowered. Furthermore, there is a disadvantage that noise is generated when the outside air is sucked from the suction port not covered with the recording sheet, and the noise increases.

  Recently, a recording apparatus that can use either cut paper or roll paper as a recording sheet has been used. In the case of recording by feeding a cut sheet, a better image can be recorded by carrying and recording while sucking the recording sheet on the platen, similarly to the case of recording on the roll sheet. However, in the recording apparatus provided with the conventional suction platen, there are the following problems when using cut paper. That is, when the trailing edge of the recording sheet is conveyed on the platen, the plurality of suction ports provided in the conveyance direction are sequentially opened from the suction port on the upstream side in the conveyance direction. Accordingly, the suction operation is performed in a state where the suction port on the upstream side in the transport direction is not covered with the recording sheet. For this reason, compared with the case where all the suction ports are covered with the recording sheet, there is a disadvantage in that wasteful energy consumption occurs, the suction capability is reduced, and the trailing edge of the recording sheet tends to be insufficiently sucked. . Furthermore, there is a disadvantage that noise is generated when the outside air is sucked from the suction port not covered with the recording sheet, and the noise increases.

  The present invention has been made in view of such technical problems. An object of the present invention is to provide a recording apparatus that can prevent a reduction in suction capability at the leading and trailing ends of a recording sheet. It is another object of the present invention to provide a recording apparatus capable of preventing a reduction in suction capability by eliminating suction from a suction port not covered with a recording sheet even in the width direction of the recording sheet.

  The present invention provides a recording head for recording on a recording sheet based on image information, guide means for guiding the recording sheet to a position facing the recording head, a plurality of suction ports arranged in the guide means, and the suction In a recording apparatus provided with suction means for sucking from the mouth, comprising a rotatable suction duct having at least one duct opening for opening and closing the suction mouth in a range corresponding to the width of the recording sheet to be recorded, As the leading end of the moving recording sheet covers the suction port, the suction duct is rotated so that the suction port is sequentially opened corresponding to the suction port being sequentially covered with the suction port. Configured.

  ADVANTAGE OF THE INVENTION According to this invention, the recording apparatus which can prevent the fall of the suction capability in the front-end | tip and rear end of a recording sheet is provided. In addition, a recording apparatus that can prevent a reduction in suction capability by eliminating suction from a suction port not covered by the recording sheet also in the width direction of the recording sheet is provided. Furthermore, noise caused by useless air suction from the suction port can be eliminated.

  Embodiments of the present invention will be specifically described below with reference to the drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings. FIG. 1 is a longitudinal sectional view of a recording apparatus suitable for applying the present invention. FIG. 2 is a perspective view of the recording apparatus of FIG. 1 as viewed from the front right. FIG. 3 is a perspective view of the recording apparatus shown in FIG. 1 to 3, the recording apparatus includes a paper feeding unit 100 that feeds cut paper, a roll paper feeding unit 200 that feeds roll paper, and the recording sheet while conveying the fed recording sheet. And a recording unit 300 for recording an image. The recording apparatus also includes an exterior part (not shown) that covers the entire apparatus, a control part (not shown) that controls the operation of the entire recording apparatus, and a power supply part (not shown). The paper feeding unit 100 separates the recording sheets that are stacked cut sheets one by one and feeds them to the recording unit 300. The roll paper feeding unit 200 feeds a recording sheet, which is a set roll paper, to the recording unit 300. The recording unit 300 records an image on the recording sheet based on image information while conveying the conveyed recording sheet.

  1 to 3, reference numeral 1 denotes a cassette for storing a recording sheet P as a recording medium, and reference numerals 2 and 3 denote an upper cover and a rear cover that constitute a part of the exterior portion. Reference numeral 4 denotes a paper discharge tray on which recording sheets to be recorded and discharged are stacked. Reference numeral 5 denotes a roll paper which is a rolled continuous paper. Reference numeral 6 denotes a roll paper setting unit. First, the flow of the recording sheet will be described. An arrow G in FIG. 1 indicates the conveyance path of the recording sheet P. The sheet feeding unit 100 includes a sheet feeding mechanism including a cassette 1, a pickup roller 11, a feed roller 12, and a retard roller 13 disposed at the lower part of the apparatus. The paper feed mechanism picks up the recording sheets stacked in the cassette 1 one by one and feeds them to the recording unit 300. The sent recording sheet passes between the intermediate roller 14 and the intermediate roller 15 and is fed to the recording unit 300.

  The recording sheet fed to the recording unit is conveyed through the recording unit by the conveying roller 16 and the pinch roller 17 and is recorded by the recording head 42 as recording means. The recording sheet is conveyed by the paper discharge roller 18 and the spur 19 after being conveyed by a certain distance in the recording unit. In the present embodiment, the recording head 42 is mounted on a carriage 41 that can reciprocate in the width direction of the recording sheet. By alternately repeating recording for one line in which recording based on image information is performed by the recording head in synchronization with the movement of the carriage (main scanning) and sub-scanning in which the recording sheet is conveyed by a predetermined pitch by the conveyance roller 16, The entire recording sheet is recorded. The recorded recording sheets are sequentially discharged to the paper discharge tray 4 and stacked there.

  Next, the sheet feeding operation of the sheet feeding unit 100 will be described. The pickup roller 11 and the feed roller 12 are driven by a conveyance motor (not shown) that is a driving unit for the conveyance roller 16. The drive transmission unit is provided with transmission means for transmitting the driving force and release means for releasing the driving force. The driving force from the conveyance motor is transmitted to the pickup roller 11 and the feed roller 12 at the same time, and the rotation of these rollers starts at the same time and stops at the same time. The retard roller 13 can be controlled so as to be urged against the feed roller 12 by the elastic means with a constant pressing force and to be separated from the feed roller 12 by the releasing means. The feed roller 12 is driven in the direction of arrow 12a, and the retard roller 13 is driven to rotate in the direction of arrow 13b. When the recording sheet is separated, it is pressed by the feed roller 12. A torque limiter is attached to the shaft support portion of the retard roller 13.

  When a certain torque is applied to the retard roller 13 in the direction of the arrow 13b, the torque limiter slips, and the retard roller 13 rotates in the direction of the arrow 13b. The retard roller 13 remains stopped if the applied torque is below a certain value. When a certain torque or more is applied in the transport direction, the motor rotates in the transport direction. This constant torque is hereinafter referred to as torque T. When there is no recording sheet between the feed roller 12 and the retard roller 13 or when one recording sheet is nipped, the torque T of the retard roller compared to the torque applied from the feed roller 12 to the retard roller 13. Is set small. For this reason, the retard roller 13 is driven by the feed roller 12 and rotates in the transport direction.

  When two or more recording sheets enter the nip, the torque due to friction between the plurality of recording sheets is smaller than the torque T of the retard roller 13, so the retard roller 13 does not rotate and remains stopped. For this reason, the recording sheet on the side in contact with the retard roller 13 is not conveyed, and only the recording sheet in contact with the feed roller 12 is conveyed. By the above operation, only the uppermost layer of the recording sheet sent out by the pickup roller 11 is separated and fed to the recording unit. The recording sheet fed by the feed roller 12 is guided and conveyed by the inner and outer U-turn guides 31 and 32.

  An intermediate roller 14 is disposed at a position where the recording sheet conveyance direction changes in the direction toward the front of the apparatus. The intermediate roller 14 is driven by a transport motor that is a drive source of the transport roller 16. The intermediate roller 15 is pressed against the intermediate roller 14 by elastic means so as to be driven to rotate. A jam sensor 21 is disposed between the intermediate roller 14 and the feed roller 12. The recording sheet conveyed from the lower part to the upper part at the back of the apparatus from the feed roller 12 and the intermediate roller 14 along the U-turn guides 31 and 32 is turned in the horizontal direction toward the front of the apparatus. As a result, the recording sheet P is turned upside down between the stacked state in the cassette 1 and the transported state in the recording unit 300.

  On the other hand, when the recording sheet is fed from the roll paper feeding unit 200, the roll paper 5 wound around the roll paper setting unit 6 is pulled out through the roll paper guide 7, and the leading ends of the intermediate roller 14 and the intermediate roller 15 are pulled out. Hold between. Then, the intermediate roller 14 is driven by the conveyance motor, and the sheet is fed between the conveyance roller 16 and the pinch roller 17. Next, the roll paper is conveyed through the recording unit 300 by driving the conveyance roller, and an image is recorded on the roll paper by the recording head 42.

  An edge sensor 22 that detects the leading edge and the trailing edge of the recording sheet is disposed downstream of the intermediate roller 14 in the conveyance direction. Further downstream, a conveying means including a conveying roller 16 and a pinch roller 17 for conveying the recording sheet in the recording unit 300 is disposed. The conveyance roller 16 is driven by a conveyance motor (not shown) via a transmission mechanism (not shown). The pinch roller 17 is pressed against the transport roller 16 by elastic means so as to be driven to rotate, and applies a transport force to the recording sheet entering the nip.

  Here, the conveyance speed of the conveyance roller 16 is set to be slightly higher than the conveyance speed of the intermediate roller 14. The reason for this is as follows. That is, when the conveyance speed of the intermediate roller 14 is higher, a recording sheet loop is generated as the recording sheet is conveyed. When this loop becomes large, the load acting on the transport roller 16 in contact with the U-turn guides 31, 32, etc. fluctuates, and the transport amount tends to become unstable. In order to prevent such inconvenience, the conveying speed of the conveying roller 16 is set to be slightly higher than that of the intermediate roller 14. Further, the conveying force of the conveying roller 16 is set to be larger than the conveying force of the intermediate roller 14. As a result, the recording sheet is conveyed by the conveying roller 16 while slightly sliding with respect to the intermediate roller 14.

  Next, the recording unit 300 will be described. The recording head 42 of the present embodiment is composed of a replaceable cartridge and is detachably mounted on the carriage 41. In the present embodiment, an ink jet recording apparatus using an ink jet recording head is illustrated. A plurality of ejection port arrays for ejecting different inks are formed on the ejection surface of the inkjet recording head 42 facing the recording sheet. Each discharge port array is configured by arranging a plurality of fine discharge ports in one row. Further, the recording head 42 of the present embodiment selectively drives the electrothermal conversion element provided in each ejection port based on the image information, and the ink is ejected from the ejection port by the film boiling pressure generated in the ink due to heat generation. Is discharged.

  The carriage 41 on which the recording head 42 is mounted is guided and supported so as to be capable of reciprocating in the direction of arrow H along a guide shaft 43 and a guide rail (not shown) provided in the left-right direction of the apparatus main body. The reciprocating movement of the carriage 41 is performed via a timing belt 46 that is stretched around a pulley 45 by a carriage motor (not shown). A platen 33 serving as guide means for guiding and supporting a recording sheet to be recorded is disposed at a position facing the ejection surface of the recording head 42. On the downstream side of the platen 33 in the recording sheet conveyance direction, a paper discharge roller 18 that is driven in synchronization with the conveyance roller 16 is disposed. A spur 19 for applying a conveyance force to the recording sheet is pressed against the discharge roller by an elastic force. The conveyance of the recording sheet during the recording operation and the discharge of the recorded recording sheet are performed by a conveyance roller 16 and a discharge roller 18 that are driven synchronously.

  Signal transmission and power supply from the electric circuit of the apparatus main body to the recording head 42 are performed by a flexible cable 47. One end of the flexible cable 47 is connected to a substrate disposed on the carriage 41, and the recording head 42 and the carriage 41 are connected via electrical contacts. An encoder sensor 48 is attached to the carriage 41, and a scale 49 is stretched on the apparatus main body side. By reading the scale 49 with the encoder sensor 48, the position and speed of the recording head 42 in the main scanning direction are detected.

  A recovery mechanism for maintaining and recovering the ink ejection performance of the recording head 42 is provided at a predetermined position (usually the carriage home position) within the range of reciprocation of the carriage 41 and out of the recording area. . The recovery mechanism portion is provided with a cap that covers the ejection port of the recording head to prevent ink evaporation and dust adhesion. This cap is also used to receive ink discharged from the discharge port. The cap is connected to negative pressure generating means such as a suction pump for applying a negative pressure in the cap. By operating the negative pressure generating means in the capping state, a suction recovery process is performed in which ink is sucked from the discharge port and the ink in the discharge port is refreshed. The recovery mechanism section also includes suction recovery means for performing such suction recovery processing. Further, wiping means is provided for wiping and removing ink, dust and the like adhering to the ejection surface of the recording head with a wiper.

  The spur 19 that is pressed by the paper discharge roller 18 is made of a highly water-repellent material, and is in contact with the recording surface of the recording sheet only at the blade-shaped circumferential portion, even if it contacts an unfixed image immediately after recording. It is configured not to affect the image. Further, the spurs 19 are arranged at a plurality of locations at predetermined positions in the main scanning direction by bearing members at positions facing the paper discharge rollers 18. Between the conveying roller 16 and the paper discharge roller 18, a platen 33 that constitutes a guide unit for guiding the recording sheet P to a predetermined position facing the recording head 42 is disposed. The platen 33 of the present embodiment is provided with a suction unit 500 for restricting the recording surface of the recording sheet to the recording head 42 to a predetermined position by attracting the conveyed recording sheet P to the upper surface of the platen.

  4A and 4B are diagrams showing a guide unit (platen) and a suction unit of the recording apparatus according to the first embodiment of the invention, wherein FIG. 4A is an external perspective view, and FIG. 4B is an exploded perspective view. 5 is a view showing a suction duct of the suction unit of FIG. 4, wherein (a) is a perspective view showing a state in which the duct opening corresponding to the maximum width recording sheet is located at the upper part, and (b) is a minimum width. It is a perspective view which shows the state which the duct opening corresponding to the recording sheet of this is located in the upper part. 4 and 5, the suction unit 500 is integrally provided below the platen 33. The suction unit 500 includes a duct case 50 formed of a cylindrical housing that is integrally attached to the lower side of the platen 33. Inside the duct case 50, a suction duct 51 made of a concentric cylindrical casing is fitted and mounted so as to be rotatable.

  A shaft 51a serving as a rotation center is provided at one end portion (left end portion in the drawing) of the suction duct 51. The shaft 51a is rotatably supported on the end face wall on the same side of the duct case 50, and from the end wall. It protrudes outward. A duct motor 53 for rotationally driving the suction duct 51 is connected to the protruding portion of the shaft 51a so as to be able to transmit the drive. In the present embodiment, the suction duct 51 is rotated by driving a motor pulley 53a of the duct motor 53, a driven pulley (not shown) fixed to the shaft 51a of the suction duct 51, and a timing belt 54 wound around these pulleys. Done through. A circular code scale 55 is attached to the shaft 51a of the suction duct. By reading the scale of the scale 55 with the encoder sensor 56, the rotation position (rotation angle) of the suction duct 51 is detected. This detection result is transmitted to the control unit of the recording apparatus.

  The other end portion (right end portion in the drawing) of the duct case 50 is an open end, and a platen fan 52 as a suction means is attached to the case open end 50b. The platen fan 52 constitutes suction means for sucking the recording sheet P onto the platen by suction from a suction port 33 a formed in the platen 33. The platen fan 52 is provided with a fan discharge port 52a and a fan suction port 52b. The end surface (the end surface on the right side of the drawing) of the suction duct 51 on the platen fan side is open, and this open end is a duct discharge port 51b. The suction duct 51 is rotatably connected to the fan suction port 52b of the platen fan at the duct discharge port 51b. Thus, the suction duct 51 is rotatably fitted and supported inside the duct case 50, and the inside of the suction duct 51 is connected to the platen fan 52 so as to be suckable.

  A case opening 50 a is formed in the duct case 50 that is positioned and fixed to the platen 33. The case opening 50a is formed at a position corresponding to a plurality of suction ports 33a formed in a predetermined arrangement on the platen, and has a size that covers all the suction ports 33a. In the present embodiment, as shown in FIG. 6, two duct openings 51 c and 51 d are formed on the cylindrical surface of the suction duct 51. These two duct openings have the same dimension in the recording sheet conveyance direction (rotation direction of the suction duct), and have different dimensions in the width direction of the recording sheet. The dimensions of the duct openings 51c and 51d in the recording sheet conveyance direction are selected to be longer than the arrangement length of the suction ports 33a formed in the platen 33 in the recording sheet conveyance direction.

  The positions of the duct openings 51c and 51d in the recording sheet width direction are aligned with the same reference position at one end thereof (the right end in the figure). Therefore, the length A of the duct opening 51c in the recording sheet width direction is a length corresponding to the width dimension of the maximum width recording sheet to be used. For example, the length A2 is the maximum width recording sheet. It corresponds. On the other hand, the length B of the duct opening 51d in the width direction of the recording sheet is a length corresponding to the width dimension of the minimum width recording sheet to be used, for example, the width of A4 size which is the minimum width recording sheet. It corresponds. The suction duct 51 in which such a duct opening is formed constitutes an opening / closing means that opens and closes a predetermined range of suction ports 33a arranged on the platen 33 in accordance with the rotational position.

  When a recording sheet having an A2 width (maximum width) is conveyed onto the platen 33, when recording is performed on the recording sheet having an A2 width, the following operation is performed. At this time, the duct motor 53 as the driving means is driven to rotate the suction duct 51 as the opening / closing means so that the duct opening 51c is positioned corresponding to the suction port 33a of the platen 33. Then, air is sucked from the suction port 33a of the platen 33 through the suction duct 51 by driving the platen fan 52 as suction means. That is, by driving the platen fan 52, the suction is performed from the fan suction port 52b through the suction port 33a, the duct opening 51c, the inside of the suction duct 51, the duct discharge port 51b, and the case open end 50b. Air sucked from the fan suction port 52b is discharged from the fan discharge port 52a. By such suction operation, the A2 width (maximum width) recording sheet conveyed onto the platen serving as the guide means is sucked and sucked onto the platen.

  On the other hand, when a recording sheet having an A4 width (minimum width) is conveyed on the platen 33, when recording on the recording sheet having an A4 width, the following operation is performed. At this time, the duct motor 53 is driven to rotate the suction duct 51 serving as the opening / closing means so that the duct opening 51d is located at a position corresponding to the suction port 33a of the platen 33. Then, by driving the suction fan 52, air is sucked from the suction port 33 a of the platen 33 through the suction duct 51. That is, by driving the platen fan 52, the suction is performed from the fan suction port 52b through the suction port 33a, the duct opening 51d, the inside of the suction duct 51, the duct discharge port 51b, and the case open end 50b. Air sucked from the fan suction port 52b is discharged from the fan discharge port 52a. By such a suction operation, the A4 width recording sheet conveyed on the platen is adsorbed on the platen.

  According to the above suction operation, when a recording sheet having an A4 width (minimum width) is sucked, it can be sucked only from the suction port at a position corresponding to the A4 width in the suction port 33a of the platen. In other words, since all the suction ports not covered by the recording sheet are closed, no suction is made from the suction ports that are opened unnecessarily. For this reason, the fall of suction capability can be prevented. In addition, since there is no suction port left unnecessarily open, it is possible to prevent an increase in noise due to outside air passing through the suction port.

  The control unit for controlling the suction operation is provided as a part of the main control unit for controlling the entire recording apparatus. The main control unit includes a CPU such as a microprocessor, a ROM that records CPU control programs and various data, and a RAM that is used as a work area for the CPU and temporarily stores various data. Is provided. A drive circuit and various sensors of each motor such as a carriage motor (not shown), a conveyance motor (not shown), a platen fan 52, and a duct motor 53 are connected to the main control unit. As a part of these various sensors, the edge sensor 22 (FIG. 1) for detecting the front and rear ends of the recording sheet, the encoder sensor 48 (FIG. 1) for detecting the position of the carriage 41, and the rotational position and amount of the suction duct 51 are detected. An encoder sensor 56 (FIG. 4) is provided. Each motor is driven according to a command from the control unit.

  FIG. 6 is a view showing a suction operation in the platen of the recording apparatus according to the first embodiment of the present invention, and (a) to (e) are cross-sectional views of each operation sequence. Next, a suction operation in the platen 33 when recording on a recording sheet will be described with reference to FIG. First, the operation of the suction duct 51 when transporting A4 size cut paper will be described. When a recording command for recording an image on an A4 width recording sheet is received from the connected computer to the recording apparatus, the CPU constituting the control unit drives the conveyance motor. By driving the conveyance motor, the pickup roller 11 rotates, and the roller surface comes into contact with the upper surface of the recording sheet stacked on the cassette 1. At this time, simultaneously with the rotation of the pickup roller 11, the feed roller 12, the intermediate roller 14, the transport roller 16 and the paper discharge roller 18 also start to rotate.

  By the feed roller 12 and the retard roller 13, one of the uppermost layers of the recording sheets fed out by the pickup roller 11 is separated and fed. When the leading edge of the recording sheet is detected by the jam sensor 21 and nipped between the intermediate roller 14 and the intermediate roller 15, the driving of the feed roller 12 is released. Further, the elastic means that pressurizes the retard roller 13 is also released. When the recording sheet is conveyed by the intermediate roller 14 and the intermediate roller 15 and the leading edge of the sheet is detected by the edge sensor 22, the platen fan 52 as a suction unit is driven. At this time, as shown in FIG. 6A, all the suction ports 33a of the platen are closed.

  When the recording sheet is further conveyed, the leading end thereof is nipped between the conveying roller 16 and the pinch roller 17. And it is conveyed by the conveyance roller 16 on the platen 33 which is a guide means. When the leading edge of the recording sheet P is conveyed on the platen 33, the suction duct 51 is rotated in the arrow R direction by driving the duct motor 53 as driving means in accordance with the movement of the leading edge (in the arrow J direction). Go. As the leading edge of the sheet reaches the suction port 33a on the upstream side in the transport direction, as shown in FIG. 6B, the duct opening 51d corresponds (matches) with the suction port 33a on the upstream side in the transport direction. The suction duct 51 as the opening / closing means is rotated. At this time, only the suction port 33a covered with the recording sheet P on the upstream side in the conveyance direction is opened, that is, the recording sheet is sucked.

  As the recording sheet is further conveyed and the leading edge of the recording sheet covers the suction port 33a, the suction duct 51 is rotated in the direction of the arrow R so that the covered suction ports 33a are sequentially opened. When the recording sheet covers all the suction ports 33a in the transport direction, the suction duct 51 is rotated so that the duct openings 51d correspond to (combine with) all the suction ports. After all the suction ports in the transport direction are covered in this way, the drive of the duct motor 53 is stopped and the rotation of the suction duct 51 is stopped. When the recording sheet is conveyed to the image forming position, the conveyance motor is stopped to stop conveyance of the recording sheet. Therefore, the carriage motor is driven to move the carriage 41 and the recording head 42 in the main scanning direction, and the recording head 42 is driven based on the image information in synchronization with this movement. Thereby, recording for one line is performed on the recording sheet. In an ink jet recording apparatus, recording is performed by ejecting ink from ejection ports arranged on the ejection surface of a recording head.

  When the recording for one line is completed, the conveying motor is driven again to rotate the conveying roller 16 by a predetermined amount, and the recording sheet is conveyed by a predetermined pitch. When the sheet is conveyed by a predetermined pitch, the conveyance motor is stopped, and the next one line is recorded while moving the carriage. An image is recorded on a recording sheet by alternately repeating the recording for one line and the paper feeding at a predetermined pitch. FIG. 6C shows a state when an image is recorded on the recording sheet.

  While the recording sheet is conveyed, the trailing edge of the recording sheet is detected by the edge sensor 22. When the trailing edge of the recording sheet passes through the nip between the conveyance roller 16 and the pinch roller 17, the duct motor 53 is driven to rotate the suction duct 51 in the direction of the arrow R. As the rear end of the recording sheet moves on the platen 33 and passes over the suction port 33a covered with the recording sheet, the suction opening 33a is sequentially closed by rotating the suction duct 51. Move. FIG. 6D shows a state when the suction port 33a is sequentially closed. The suction duct 51 is rotated to move the duct opening 51d so that all the suction ports are closed when the trailing edge of the recording sheet passes through all the suction ports 33a in the transport direction. After all the suction ports are closed, the drive of the duct motor 53 is stopped and the rotation of the suction duct 51 is stopped. FIG. 6E shows the state at this time. Next, the driving of the platen fan 52, which is a suction unit, is stopped, and a series of suction operations is finished.

  Next, the operation of the suction duct 51 when transporting A2 size cut paper will be described. In this case, a recording command for recording an image on an A2 width recording sheet comes from the connected computer to the recording apparatus. When a recording command is received, the CPU constituting the control unit drives the transport motor, and the same transport operation as described above is performed. When the recording sheet is conveyed onto the platen 33, a suction operation by the suction unit 500 is performed. In this case, the suction duct 51 is rotated so that the duct opening 51c for the A2 width (maximum width) moves to a position corresponding to the suction port 33a of the platen instead of the duct opening 51d in the case of the A4 width described above. I will let you. The suction operation in the case of the A2 width is different from the above-described suction operation in the case of the A4 width, and is the same in other points.

  When the A2 width recording sheet is conveyed, the A2 width duct opening 51c corresponds to the suction port 33a in the transport direction so that the suction port 33a is sequentially opened corresponding to the position of the front end of the sheet on the platen 33. The suction duct 51 is rotated so as to reach the position. That is, the suction ports are sequentially opened as the leading edge of the sheet covers the suction port 33a from the upstream in the transport direction. When the trailing edge of the sheet is conveyed on the platen at the end of the recording operation, the suction duct 51 is rotated so that the suction opening 33a is sequentially closed in the conveying direction according to the position of the trailing edge of the sheet, thereby opening the duct opening 51c. I will move it. Accordingly, in the case of the A2 width, as in the case of the A4 width, when the leading edge and the trailing edge of the recording sheet are conveyed on the platen 33, all the suction ports 33a in the range not covered with the recording sheet are closed. Then, the suction operation is performed in a state where only the suction port 33a in the range covered with the recording sheet is opened. For this reason, the suction capability does not decrease when the leading edge and the trailing edge of the recording sheet pass.

  When a recording sheet having a small width such as A4 size is conveyed, the suction operation is performed in the width direction with the suction port 33a not covered with the recording sheet being closed. For this reason, it is possible to prevent a reduction in suction capability regardless of the width of the conveyed recording sheet. Further, since the suction operation can be performed in the sub-scanning direction and the main scanning direction with all the suction ports not covered by the recording sheet closed, noise caused by the outside air being sucked from the waste suction ports Generation or noise increase can be prevented. Further, since the suction duct 51 has a cylindrical shape and the suction duct opening / closing means for opening and closing the suction opening 33a of the platen by rotating the suction duct 51 is configured, the recording sheet can be efficiently transferred to the platen without increasing the size of the apparatus. 33 can be adsorbed.

  FIG. 7 is a view showing a suction duct of the suction unit of the recording apparatus according to the second embodiment of the present invention. FIG. 7A is a perspective view showing a state in which the duct opening corresponding to the maximum width recording sheet is located at the top. FIG. 7B is a perspective view showing a state in which the duct opening corresponding to the intermediate width recording sheet is located at the upper part. FIG. 7C is a perspective view showing a state in which the duct opening corresponding to the recording sheet having the minimum width is located at the top. The second embodiment is different from the first embodiment in that the number and size of duct openings formed in the suction duct 51 are different, and has the same configuration in other respects. The duct opening of the suction duct 51 will be described with reference to FIG. In FIG. 7, a duct opening 51c, a duct opening 51d, and a duct opening 51e are formed at three locations in the circumferential direction of the peripheral wall of the cylindrical suction duct 51. These three duct openings have the same dimensions in the transport direction as in the above-described embodiment, but have different dimensions (lengths) in the recording sheet width direction. Further, the length of the three duct openings 51c, 51d and 51e in the transport direction is larger than the transport direction arrangement length of the suction port 33a on the platen 33, and is selected to a value that covers the transport direction arrangement range of the suction port. Yes.

  The length A in the recording sheet width direction of the duct opening 51c is a length corresponding to the width of the maximum recording sheet, and corresponds to the A2 width in this embodiment. The length B of the duct opening 51d corresponds to the width of the minimum width recording sheet, and corresponds to the A4 width in this embodiment. The length C of the duct opening 51e corresponds to the A3 width which is an intermediate width in the present embodiment. When transporting and recording an A2 width recording sheet on the platen 33, the duct motor 53 is driven to rotate the suction duct 51 so that the duct opening 51c is located at a position corresponding to the suction port 33a. Then, the platen fan 52 is driven. Thus, outside air is sucked into the fan suction port 52b of the platen fan through the suction port 33a, the case opening 50a, the duct opening 51c, the inside of the suction duct 51, the duct discharge port 51b, and the case open end 50b. The air sucked by the platen fan is discharged from the fan discharge port 52a. By this operation, the A2 width recording sheet conveyed on the platen is sucked and adsorbed by the platen 33.

  When transporting and recording an A4 width recording sheet on the platen 33, the duct motor 53 is driven to rotate the suction duct 51 so that the duct opening 51d is at a position corresponding to the suction port 33a. Then, the platen fan 52 is driven. Thus, the outside air is sucked into the fan suction port 52b of the platen fan through the suction port 33a, the case opening 50a, the duct opening 51d, the inside of the suction duct 51, the duct discharge port 51b, and the case open end 50b. The air sucked into the platen fan is discharged from the fan discharge port 52a. By this operation, the A4 width recording sheet conveyed on the platen is sucked and adsorbed by the platen 33.

  When a recording sheet having an A3 width is conveyed, the duct motor 53 is driven to rotate the suction duct 51 so that the duct opening 51e is at a position corresponding to the suction port 33a. Then, the platen fan 52 is driven. Thereby, outside air is sucked into the fan suction port 52b of the platen fan through the suction port 33a, the case opening 50a, the duct opening 51e, the inside of the suction duct 51, the duct discharge port 51b, and the case open end 50b. The air sucked into the platen fan is discharged from the fan discharge port 52a. By this operation, the A3-width recording sheet conveyed on the platen is sucked and adsorbed by the platen 33.

In the first embodiment described above, only two types of recording sheets of A2 width and A4 width are supported. On the other hand, in this embodiment, by adding the duct opening 51e, the suction operation using only the suction port at the position corresponding to the A3 width of the suction ports 33a when recording on the A3 width recording sheet is performed. It can be carried out. Accordingly, it is possible to cope with a total of three types of recording sheets obtained by adding the A3 width to the A2 width and the A4 width.
In the first embodiment, two duct openings are provided, and in the second embodiment, three duct openings are provided to correspond to two recording sheet widths or three recording sheet widths. However, in carrying out the present invention, the suction duct 51 is provided with a number of duct openings corresponding to a larger number of recording sheet widths, thereby eliminating a decrease in suction capability when using recording sheets having a larger number of different widths. Is possible. Further, in these cases, it is possible to prevent the generation of noise from the suction port 33a that has been opened unnecessarily.

  FIG. 8 is a view showing a suction duct of the suction unit of the recording apparatus according to the third embodiment of the present invention. FIG. 8A is a perspective view showing a state in which the duct opening corresponding to the maximum width recording sheet is located at the top. FIG. 8B is a perspective view showing a state in which the duct opening corresponding to the recording sheet having the intermediate width is positioned at the upper part. FIG. 8C is a perspective view showing a state in which the duct opening corresponding to the recording sheet having the minimum width is located at the top. This embodiment differs from the first and second embodiments described above only in the shape structure of each duct opening of the suction duct 51, and is substantially the same in other respects. The third embodiment of FIG. 8 is the same as the second embodiment in that three duct openings 51c, 51d, 51e are provided in accordance with the width of the recording sheet.

  However, in the third embodiment, each of the duct openings 51c, 51d, and 51e is not formed by one opening, but includes a plurality of small openings (through holes) arranged in the width direction of the recording sheet. It consists of a group of through holes. The position of each through hole group and the width in the conveyance direction correspond to the range in the conveyance direction of the suction port 33a of the platen 33. According to the third embodiment, in addition to the effects of the first and second embodiments described above, duct openings corresponding to recording sheets of various sizes can be appropriately formed while maintaining the strength of the suction duct 51. There is an effect that it can be added.

  The recording apparatus according to the embodiment described above includes the recording head 42 that records on a recording sheet based on image information, and the platen 33 that is guide means for guiding the recording sheet to a position facing the recording head. . Furthermore, a plurality of suction ports 33a arranged in the guide means and a platen fan 52 which is a suction means for sucking from the suction ports are provided. In such a recording apparatus, a suction duct 51 is provided as opening / closing means having duct openings 51c and 51d for opening and closing the suction port 33a. The opening / closing range of the suction port 33a is changed by changing the rotational position of the opening / closing means 51 in accordance with the conveyance direction position of the recording sheet guided by the guide means 33 and the width of the recording sheet. .

  According to the embodiment described above, since suction is performed by opening only the suction port covered with the recording sheet, it is possible to prevent a reduction in suction capability at the leading and trailing ends of the recording sheet. Also, in the width direction of the recording sheet, it is possible to prevent a reduction in suction capability by eliminating suction from the suction port not covered with the recording sheet. Furthermore, noise caused by useless air suction from the suction port can be eliminated. Further, since the opening / closing means is formed by the cylindrical suction duct 51 and the suction duct 33 is rotated to open and close the suction port 33a, the suction port 33a in a predetermined range can be accurately set without increasing the size of the apparatus. Can be opened and closed.

  In the above embodiment, two or more duct openings are provided in the suction duct 51 according to the width of the recording sheet to be recorded. However, in the practice of the present invention, depending on the type of recording sheet to be recorded, only one duct opening may be provided in the suction duct 51 which is an opening / closing means, and the same effect can be obtained. Further, as for the number of duct openings of the opening / closing means 51, four or more of different lengths may be provided according to the necessity such as the number of types of recording sheets.

  In the above embodiment, the serial recording apparatus that performs recording with the recording head mounted on the carriage has been described as an example. However, the present invention can be similarly applied to other recording methods such as a line recording apparatus that records only one line at a time while recording only by paper feed (sub-scan). In addition, the present invention can be applied regardless of the number and arrangement of the recording heads. Furthermore, the present invention can be applied regardless of the recording method and size of the apparatus, such as an inkjet recording apparatus, a thermal transfer recording apparatus, a laser recording apparatus, a thermal recording apparatus, and a wire dot recording apparatus.

1 is a longitudinal sectional view of a recording apparatus suitable for applying the present invention. It is the perspective view seen from the right front of the recording device of FIG. FIG. 2 is a perspective view of the recording apparatus of FIG. 2A and 2B are diagrams illustrating a guide unit (platen) and a suction unit of the recording apparatus according to the first embodiment of the invention, in which FIG. 1A is an external perspective view, and FIG. 2B is an exploded perspective view. 5A and 5B are views showing a suction duct of the suction unit of FIG. 4, wherein FIG. 5A is a perspective view showing a state in which a duct opening corresponding to the maximum width recording sheet is located at an upper portion, and FIG. 5B is a minimum width recording sheet. It is a perspective view which shows the state in which the duct opening corresponding to is located in the upper part. 2A and 2B are diagrams illustrating a suction operation in the platen of the recording apparatus according to the first exemplary embodiment of the present invention, and FIGS. It is a figure which shows the suction duct of the suction unit of the recording device which concerns on the 2nd Embodiment of this invention. FIG. 7A is a perspective view showing a state in which the duct opening corresponding to the maximum width recording sheet is located at the top. FIG. 7B is a perspective view showing a state in which the duct opening corresponding to the intermediate width recording sheet is located at the upper part. FIG. 7C is a perspective view showing a state in which the duct opening corresponding to the recording sheet having the minimum width is located at the top. It is a figure which shows the suction duct of the suction unit of the recording device which concerns on the 3rd Embodiment of this invention. FIG. 8A is a perspective view showing a state in which the duct opening corresponding to the maximum width recording sheet is located at the top. FIG. 8B is a perspective view showing a state in which the duct opening corresponding to the recording sheet having the intermediate width is positioned at the upper part. FIG. 8C is a perspective view showing a state in which the duct opening corresponding to the recording sheet having the minimum width is located at the top.

Explanation of symbols

33 Guide means (platen)
33a Suction port 42 Recording head 50 Duct case 51 Opening / closing means (suction duct)
51c, 51d, 51e Duct opening 52 Suction means (platen fan)
500 suction unit

Claims (10)

A recording head for recording on a recording sheet based on image information, guide means for guiding the recording sheet to a position facing the recording head, a plurality of suction ports arranged in the guide means, and suction from the suction ports In a recording apparatus comprising suction means,
A rotatable suction duct having at least one duct opening for opening and closing the suction port in a range corresponding to the width of the recording sheet to be recorded, the leading end of the moving recording sheet covering the suction port The recording apparatus is characterized in that the suction duct is rotated so that the duct opening sequentially corresponds to the suction opening that is covered and the suction opening is sequentially opened. The suction duct is rotated so as to close the suction port according to the position of the rear end of the recording sheet as the rear end of the moving recording sheet passes through the suction port covered by the recording sheet. The recording apparatus according to claim 1, characterized in that: The recording apparatus according to claim 1, wherein the duct opening opens and closes the suction port in a range corresponding to a width of a recording sheet to be recorded. The recording apparatus according to claim 1, wherein the suction port in a range not covered with the recording sheet in the width direction of the recording sheet is kept closed. The duct opening is used to open and close the suction opening within a range corresponding to the maximum width of the recording sheet to be recorded, and to open and close the suction opening within a range corresponding to the minimum width of the recording sheet to be recorded. The recording apparatus according to claim 1, further comprising: a duct opening. When the width of the recording sheet is small , the suction duct has a position where the duct opening having a small width direction corresponds to the suction opening, and when the recording sheet has a large width, the duct opening having a large width direction is the suction opening. The recording apparatus according to claim 3, wherein the recording apparatus is rotationally driven so as to be in a position corresponding to the mouth. A recording head for recording on a recording sheet based on image information, a platen for guiding the recording sheet to a position facing the recording head, a plurality of suction ports for adsorbing the recording sheet provided on the platen, and In a recording apparatus comprising: a suction unit provided on the lower side of the platen for adsorbing a recording sheet through a suction port;
The suction unit includes a duct case having openings formed at positions corresponding to the plurality of suction ports, a suction duct rotatably accommodated in the duct case, and a platen communicating with the inside of the suction duct. With a fan,
The suction duct is provided with at least one duct opening having a length in the width direction corresponding to the width of the recording sheet to be recorded,
When the recording sheet is transported on the platen, the duct opening sequentially corresponds to the suction opening which is covered as the leading end of the transported recording sheet covers the suction opening. The recording apparatus is characterized in that the suction duct is rotated so that the two are sequentially opened. The trailing edge of the recording sheet being conveyed. 8. The suction duct is rotated so as to sequentially close the suction port according to the position of the rear end of the recording sheet as it passes through the suction port covered with the recording sheet. Recording device. The duct opening having a width width direction length corresponding to the recording sheet to be used, in claim 7, characterized in that it has one length corresponding to the width of the recording sheet of the maximum width of which The recording device described. The duct opening having a width width direction length corresponding to the recording sheet to be used, in claim 7, characterized in that it has one length corresponding to the width of the recording sheet of the minimum width of which The recording device described.

Images