JP2008068492A - Recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a highly precise conveyance, secured by controlling using an encoder sensor in the conveyance using a highly precise roller, makes it difficult to retain the conveyance precision with respect to the high speed because the controlling is carried out by using the highly precise roller and the encoder sensor and transmission of driving is interposed by an idler gear, and that a long head has to be used in order to secure the precision when a rear edge of a recording sheet is conveyed by a conveyance roller at a downstream side after passing through the highly precise roller. <P>SOLUTION: When one of a plurality of W encoders has a malfunction, controlling is carried out by using another normal encoder. At that time, controlling of printing is made different from that in the normal condition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording apparatus that controls a conveyance amount of a recording sheet using a plurality of conveyance units and a detection unit that detects a conveyance amount by the conveyance unit when printing on the recording sheet. In particular, the present invention relates to an abnormality handling control in the case where the plurality of transport amount detection means is as described above.

2. Description of the Related Art Conventionally, printing apparatuses such as printers are used not only for printing on plain paper but also for printing photographic images on photographic paper. In particular, ink jet printers have become smaller in size, resulting in images equivalent to or better than silver salt photographs. For this reason, high image quality is required for paper conveyance, and the main paper conveyance roller is a high-precision roller such as a roller with a metal shaft coated with a grindstone, and a DC motor is placed on the shaft. Controlled by the provided code wheel and encoder sensor, both high precision and high speed conveyance have been achieved. In case of borderless printing, an ink jet printer ejects ink from a recording head in a non-contact manner on a recording sheet to form an image, so that printing can be performed up to the rear end portion of the recording sheet with one conveying means. However, another conveying means is provided downstream of the recording head. However, at this time, when the trailing edge of the recording sheet is removed from the conveying means on the upstream side in the sheet conveying direction, the recording sheet conveying amount may change, thereby causing unevenness in the image. Therefore, as shown below, in order to ensure the conveyance accuracy of the trailing edge, the nozzles used at the time of printing at the trailing edge are throttled or the conveyance of the trailing edge is controlled, and the printing deviation is adjusted in conjunction with the shift of the nozzles used at the recording head. The invention which suppresses is proposed. Further, the conveyance accuracy on the downstream side is also ensured by increasing the mechanical accuracy (see Patent Document 1).
JP 2002-254736 A.

  However, in recent years, there has been a demand for not only high image quality but also high-speed printing. Serial recording heads are becoming longer, the number of passes for multi-pass printing is reduced, and the paper transport length is longer. It has become. Further, in order to further improve the image quality, the size of ink droplets has been reduced, and transport accuracy has been required more. In this case, in the conveyance using the high-precision roller, the high-precision conveyance could be secured by the encoder sensor control or the like. However, when the rear end passes through the roller and then is transported by the downstream transport roller, the control is performed by the encoder sensor at the high-precision transport roller. For this reason, drive transmission is also partway through idler gears, etc., making it difficult to ensure conveyance accuracy, and long heads must be squeezed to ensure accuracy, which is a major issue for speeding up. It was.

In order to achieve the above object, an invention according to the present invention is a recording apparatus that performs recording on a recording sheet by scanning the recording head, and is disposed upstream of the recording sheet conveyance direction with the scanning area of the recording head interposed therebetween. First conveying means, second conveying means arranged downstream in the recording sheet conveying direction,
Each of the first transport means and the second transport means is provided with a detection means for detecting the respective rotation amounts, and when the detection result of one of the detection means is determined to be abnormal, the detection result of the other detection means Is used to convey the recording sheet.

  When at least one of the multiple encoder sensors is abnormal, it is possible to perform good transport by performing transport control different from normal using a normal encoder sensor. Even if at least one of the above is abnormal, printing is possible without causing a failure.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view of a recording apparatus according to the first embodiment of the present invention, FIG. 2 is a perspective view of a mechanism portion of the recording apparatus according to the first embodiment of the present invention, and FIG. 3 is a first embodiment of the present invention. FIG. 4 is an explanatory view of a plurality of encoders in the first embodiment of the present invention, FIG. 5 is an explanatory view of a control area of the plurality of encoders in the first embodiment of the present invention, and FIG. 6 is a first embodiment of the present invention. FIG. 10 is a diagram illustrating a behavior when a sheet trailing edge is missing and a correction explanatory diagram in an example.

  The recording apparatus of the present invention includes a recording apparatus 1, a sheet feeding apparatus 2, a sheet feeding section 3, a carriage section 5, a sheet discharge section 4, a U-turn / automatic duplex conveying section 8, a cleaning section 6, a recording head 7, an exterior / electricity. Part 9. Then, these are divided into items and the outline is described sequentially.

(A) Paper Feed Unit The paper feed unit 2 returns the pressure plate 21 on which the sheet material P is stacked, the paper feed roller 28 that feeds the sheet material P, the separation roller 241 that separates the sheet material P, and the sheet material P back to the stacking position. Therefore, the return lever 22 and the like are attached to the base 20.

  A paper feed tray 26 for holding the stacked sheet materials P is attached to the base 20 or the exterior. The paper feed tray 26 is a multi-stage type and is pulled out for use.

  The paper feed roller 28 has a bar shape with a circular arc in cross section. One separation roller rubber is provided based on the sheet reference, and thereby the sheet material is fed. The drive to the paper feed roller 28 is transmitted by a drive transmission gear 271 and a planetary gear 272 from a motor (hereinafter referred to as an AP motor) 273 shared with a cleaning unit provided in the paper feed unit 2.

  A movable side guide 23 is movably provided on the pressure plate 21 to regulate the stacking position of the sheet material P. The pressure plate 21 can rotate about a rotation shaft coupled to the base 20 and is urged by the pressure plate spring 212 to the paper feed roller 28. A separation sheet 213 made of a material having a large coefficient of friction such as an artificial leather that prevents double feeding of the sheet material P near the end of the stack is provided at a portion of the pressure plate 21 that faces the sheet feeding roller 28. The pressure plate 21 is configured to be able to contact and separate from the paper feed roller 28 by a pressure plate cam 241.

  Further, a separation roller holder 24 attached with a separation roller 241 for separating the sheet material P one by one on the base 20 is rotatable about a rotation shaft provided on the separation base 20, and is separated by a separation roller spring 242. It is urged by the paper feed roller 28. The separation roller 241 has a configuration in which a clutch spring 243 is attached, and a portion to which the separation roller 241 is attached can rotate when a load exceeding a predetermined value is applied. The separation roller 241 can be brought into contact with and separated from the paper feed roller 28 by a separation roller release shaft 242 and a control cam 25. The positions of the pressure plate 21, the return lever 22, and the separation roller 241 are detected by the ASF sensor 29.

  A return lever 25 for returning the sheet material P to the stacking position is rotatably attached to the base 20 and is urged by a return lever spring 221 in the release direction. When returning the sheet material P, it is configured to rotate by the control cam 25.

  In a normal standby state, the pressure plate 28 is released by the pressure plate cam 214, the separation roller 241 is released by the control cam 25, and the return lever 22 returns the sheet material P so that the sheet material P does not enter the back during loading. It is provided at a loading position that closes the loading port. When paper feeding starts from this state, first, the separation roller 241 contacts the paper feeding roller 28 by driving the motor. Then, the return lever 22 is released, and the pressure plate 21 comes into contact with the paper feed roller 28. In this state, feeding of the sheet material P is started. The sheet material P is limited by the pre-stage separation unit 201 provided on the base 20, and only a predetermined number of the sheet material P is sent to the nip portion constituted by the paper feed roller 28 and the separation roller 241. The fed sheet material P is separated at the nip portion, and only the uppermost sheet material P is conveyed.

  When the sheet material P reaches a conveyance roller 36 and a pinch roller 37 described later, the pressure plate 21 is released by the pressure plate cam 213 and the separation roller 28 is released by the control cam 25. The return lever 22 is returned to the loading position by the control cam 25. At this time, the sheet material P that has reached the nip portion constituted by the paper feed roller 28 and the separation roller 241 can be returned to the stacking position.

(B) Paper feeding part The paper feeding part 3 is attached to the chassis 11 made of a bent metal sheet. The paper feeding unit 3 includes a conveyance roller 36 that conveys the sheet material P and a PE sensor 32. The transport roller 36 has a structure in which the surface of the metal shaft is coated with ceramic fine particles, and the metal portions of both shafts are received by the bearing 38 and attached to the chassis 11. A conveyance roller tension spring 381 is provided between the bearing 38 and the conveyance roller 36 in order to apply a load during rotation to the conveyance roller 36 to perform stable conveyance, and a predetermined load is applied by urging the conveyance roller 36. Giving.

  The conveyance roller 36 is provided with a plurality of driven pinch rollers 37 in contact therewith. The pinch roller 37 is held by the pinch roller holder 30 and is urged by the pinch roller spring 31, so that the pinch roller 37 is in pressure contact with the transport roller 36 and generates the transport force of the sheet material P. At this time, the rotating shaft of the pinch roller holder 30 is attached to the bearing of the chassis 8 and rotates around the shaft. Further, a paper guide flapper 33 and a platen 34 for guiding the sheet material P are disposed at the entrance of the sheet feeding unit 3 to which the sheet material P is conveyed. Further, the pinch roller holder 30 is provided with a PE sensor lever 321 that transmits detection of the leading edge and trailing edge of the sheet P to the PE sensor 32. The platen 34 is attached to the chassis 11 and positioned. The paper guide flapper 33 engages with the transport roller 36 and can rotate around a bearing portion 331 that slides, and is positioned by contacting the chassis 11.

  In the above configuration, the sheet material P sent to the paper feeding unit 3 is guided by the pinch roller holder 30 and the paper guide flapper 33, and sent to the roller pair of the transport roller 36 and the pinch roller 37. At this time, the leading edge of the sheet material P conveyed by the PE sensor lever 35 is detected, and thereby the printing position of the sheet material P is obtained. Further, the sheet material P is conveyed on the platen 34 by the roller pair 36 and 37 being rotated by the conveyance motor 35. On the platen 34, a rib serving as a conveyance reference surface is formed. The gap with the recording head 7 is managed, and the sheet material P is controlled in combination with a later-described paper discharge unit. And, it is configured so that the smashing does not become large.

  The drive to the transport roller 36 is transmitted by a timing belt 39 to a pulley 361 provided on the shaft of the transport roller 36 by a timing belt 39. Further, a code wheel 362 on which markings are formed at a pitch of 150 to 300 lpi for detecting a conveyance amount by the conveyance roller 36 is provided on the axis of the conveyance roller 36, and an encoder sensor 363 that reads the code wheel 362 is a code wheel. It is attached to the chassis 11 at the position 362 adjacent thereto.

  A recording head 7 that forms an image based on image information is provided on the downstream side of the conveying roller 36 in the sheet material conveying direction. As the recording head 7, an ink jet recording head equipped with a replaceable ink tank for each color ink tank is used. The recording head 7 can apply heat to the ink by a heater or the like. Then, the film of the ink is boiled by this heat, and the ink is ejected from the nozzle 70 of the recording head 7 by the pressure change caused by the growth or contraction of the bubbles due to the film boiling, and an image is formed on the sheet material P. At this time, the sheet material P is held by the platen 34, and the distance from the nozzle 70 to the printing surface of the sheet material P is maintained at a predetermined amount.

  Further, when full-surface printing (borderless printing) is performed, the ink that protrudes from the edge of the sheet material P is transferred from the edge of the sheet material P to the platen 34 that faces the ink discharge port of the head 7. A platen absorber 344 for absorbing is provided. All the ink that protrudes from the four side edges of the sheet material P is absorbed here.

(C) Carriage unit The carriage unit 5 includes a carriage 50 to which the recording head 7 is attached. The carriage 50 is held by a guide shaft 52 for reciprocating scanning in a direction perpendicular to the conveying direction of the sheet material P, and a guide rail 111 that maintains the gap between the recording head 7 and the sheet material P by holding the rear end of the carriage 50. It is supported. The guide shaft 52 is attached to the chassis 11. The guide rail 111 is formed integrally with the chassis 11.

  The carriage 50 is driven via a timing belt 541 by a carriage motor 54 attached to the chassis 11. The timing belt 541 is stretched and supported by an idle pulley 542. The timing belt 542 is coupled to the carriage 50 via a damper 55 made of rubber or the like, and reduces image unevenness by attenuating vibration of the carriage motor 54 or the like. A code strip 561 in which markings are formed at a pitch of 150 to 300 lpi for detecting the position of the carriage 50 is provided in parallel with the timing belt 541. In addition, an encoder sensor 56 for reading it is provided on a carriage substrate 92 mounted on the carriage 50. The carriage substrate 92 is also provided with contacts 921 for electrical connection with the recording head 7. Further, the carriage 50 is provided with a flexible substrate 57 for transmitting a recording head 7 head signal from the electric substrate 9.

  In order to fix the recording head 7 to the carriage 50, the carriage 50 is provided with pressing means 511 for pressing and fixing the abutting portion 501 for positioning. The pressing means 511 is mounted on the head set lever 51 and is configured to act on the recording head 7 when the head set lever 51 is turned around the rotation fulcrum and set.

  Further, eccentric cams 521 are provided at both ends of the guide shaft 52, and the guide shaft 52 is moved up and down by transmitting the drive to the eccentric cam 521 through the gear train 591 by the main cam 63 of the cleaning unit 6. be able to. As a result, the carriage 50 can be moved up and down to form an optimum gap even for the sheet material P having a different thickness.

  Further, an automatic registration adjustment sensor 59 for automatically correcting the landing deviation of the ink ejected from the recording head 7 on the recording sheet P is attached to the carriage 50. The sensor 59 is a reflection type optical sensor, and an optimal registration adjustment value can be obtained by emitting light from the light emitting element and receiving reflected light to a predetermined print pattern on the recording sheet P.

  In the above configuration, when an image is formed on the sheet material P, the roller pairs 36 and 37 convey the sheet material P to the row position (position in the conveyance direction of the sheet material P) where the image is formed and the carriage 50 is moved by the carriage motor 80. The recording head 7 is moved to the row position for image formation (a position perpendicular to the conveying direction of the sheet material P), and the recording head 7 is opposed to the image formation position. Thereafter, as described above, the recording head 7 ejects ink toward the sheet material P in accordance with a signal from the electric substrate 9 to form an image.

(D) Paper Discharge Unit The paper discharge unit 4 includes two paper discharge rollers 40 and 41, paper discharge rollers 40 and 41 that are configured to contact each other with a predetermined pressure, and can be rotated by being driven. Is composed of a gear train for transmitting the driving of the paper discharge rollers 40 and 41, and the like.

  The paper discharge rollers 40 and 41 are attached to the platen 34. The discharge roller 40 on the downstream side in the conveyance direction of the recording sheet P is provided with a plurality of rubber portions 401 on a metal shaft. The discharge roller 40 is driven by the drive from the transport roller 36 acting on the discharge roller gear 404 directly connected to the discharge roller 40 via the idler gear 45. The paper discharge roller 41 provided on the upstream side of the paper discharge roller 40 is made of resin. The drive to the paper discharge roller 41 is transmitted from the paper discharge roller 40 via another idler gear. A code wheel 402 on which markings are formed at a pitch of 150 to 300 lpi for detecting the transport amount by the paper discharge roller 40 is provided on the shaft of the paper discharge roller 40, and an encoder sensor 403 that reads the code wheel 402 is provided. It is attached to the chassis 11 at a position adjacent to the code wheel 402.

  The spur 42 is a SUS thin plate provided with a plurality of convex shapes around it, is integrally molded with the resin part, and is attached to a spur holder 43. A spur spring 44 provided with a coil spring in a rod shape causes the spur 42 to be attached to the spur holder 43 and pressed against the discharge rollers 40 and 41 and the like. A spur is provided at a position corresponding to the rubber part and the elastic part of the paper discharge rollers 40 and 41, and mainly serves to generate the conveying force of the sheet material P, and the rubber of the paper discharge rollers 40 and 41 therebetween. The portion 401 and the elastic body portion 411 are provided at positions where the sheet body P is not printed, and mainly serves to suppress lifting when the sheet material P is printed.

  With the above configuration, the sheet material P on which an image is formed by the carriage unit 5 is sandwiched by the nip between the paper discharge roller 41 and the spur 42, conveyed, and discharged to the paper discharge tray 46. The paper discharge tray 46 is configured to be housed in the front cover 95. When used, pull out. The sheet discharge tray 46 increases in height toward the leading end, and both ends thereof are configured to be high in height so that the stackability of the discharged sheet material P can be improved and the printing surface can be prevented from rubbing.

(E) U-turn / automatic double-sided portion Sheet material P is stored in a cassette 81 provided on the front surface of the apparatus. In order to separate and feed the sheet material P, a pressure plate 822 on which the sheet material P is stacked and brought into contact with the sheet feeding roller 821 is provided in the cassette 81. A sheet feeding roller 821 that feeds the sheet material P, a separation roller 831 that separates the sheet material P, a return lever 824 for returning the sheet material P to the stacking position, a pressurizing / controlling unit 825 for the pressure plate 822, and the like are main bodies. The UT base 84 is attached.

  The cassette 81 has a two-stage contraction configuration, and can be selectively used depending on the size of the recording sheet P. When the small size paper or the cassette is not used, the cassette 81 contracts and can be stored inside the main body exterior portion 9.

  The paper feed roller 821 has a bar shape with a circular arc in cross section. One separation roller rubber is provided based on the sheet reference, and thereby the sheet material is fed. The drive to the sheet feeding roller 821 is transmitted from a U-turn / automatic double-side motor 85 provided on the U-turn / automatic double-side unit 5 by a drive transmission gear 851, a planetary gear 852, and the like.

  A movable side guide 827 is movably provided on the pressure plate 822 to regulate the stacking position of the sheet material P. The pressure plate 822 is rotatable about a rotation shaft coupled to the cassette 81, and is urged against the paper feed roller 821 by a pressure / control means 825 including a pressure plate spring 828 provided on the UT base 84. A separation sheet 829 made of a material having a large coefficient of friction such as an artificial leather that prevents double feeding of the sheet material P near the end of the stack is provided at a portion of the pressure plate 822 that faces the paper feed roller 821. The pressure plate 822 can be brought into contact with and separated from the paper feed roller 821 by a pressure plate cam 836.

  Further, the UT base 83 has a separation roller holder 833 attached with a separation roller 831 for separating the sheet material P one by one, and can rotate around a rotation shaft provided on the separation base 83, and a separation roller spring 837. By this, the sheet feeding roller 821 is urged. The separation roller 831 has a configuration in which a clutch spring 834 is attached, and a portion to which the separation roller 831 is attached can rotate when a load greater than a predetermined value is applied. The separation roller 241 is configured to come into contact with and separate from the paper feed roller 821 by a separation roller release shaft 835 and a control cam 836. The positions of the pressure plate 822 and the return lever 824 separation roller 831 are detected by the UT sensor 841.

  A return lever 824 for returning the sheet material P to the stacking position is rotatably attached to the UT base 83 and is urged by a return lever spring 823 in the release direction. When the sheet material P is returned, it is configured to rotate by the control cam 836.

  In a normal standby state, the pressure plate 822 is released by the pressure plate cam 836, the separation roller 831 is released by the control cam 836, and the return lever 824 returns the sheet material P so that the sheet material P does not enter the back during loading. It is provided at a loading position that closes the loading port. When paper feeding starts from this state, the motor first drives to contact the separation roller 831 paper feeding roller 821. Then, the return lever 824 is released, and the pressure plate 822 comes into contact with the paper feed roller 821. In this state, feeding of the sheet material P is started. The sheet material P is limited by the front-stage restricting means 838 provided on the base 83, and only a predetermined number of the sheet material P is sent to the nip portion constituted by the sheet feed roller 821 separation roller 831. The fed sheet material P is separated at the nip portion, and only the uppermost sheet material P is conveyed.

  When the separated and conveyed sheet material P reaches a later-described U-turn intermediate roller (1) 86 and U-turn pinch roller 861, the pressure plate 822 is released by the pressure plate cam 836 and the separation roller 831 is released by the control cam 836. The return lever 824 is returned to the loading position by the control cam 836. At this time, the sheet material P that has reached the nip portion composed of the paper feed roller 821 and the separation roller 831 can be returned to the stacking position.

  On the downstream side of the sheet feeding portion, there are two conveying rollers, a U-turn intermediate roller (2) 87 and a U-turn intermediate roller (2) 87, for conveying the sheet material fed and conveyed. Yes. In these, EPDM having a rubber hardness of 40 to 80 ° is attached to 4 to 6 locations on the core of the metal shaft. U-turn pinch rollers 861 and 871 for sandwiching the sheet material P at positions corresponding to the rubber portions are attached to the spring shaft, and are attached to the U-turn intermediate roller (1) 86 and the U-turn intermediate roller (2) 87. Energized. In order to form a transport path, an inner guide 881 that forms the inner side and an outer guide 882 that forms the outer side are configured.

  The junction point of the paper path with the paper feed unit 2 described above is configured by a flapper 883 so that the mutual path merges smoothly. When the leading edge of the recording sheet P is fed to the above-described conveyance roller 36 and pinch roller 37, the recording sheet P is brought into contact with the nip of the stopped roller pair, and the registration operation is performed.

  While being transported by the transport roller 36 and the pinch roller 37 described above, the printed sheet material P passes through the transport roller 36 and the pinch roller 37. At the time of automatic double-sided printing, the rear end of the sheet material P is again sandwiched between the conveyance roller 36 and the pinch roller 37 and conveyed. At this time, the pinch roller 37 can be smoothly conveyed because the sheet material P is fed into the rising portion by the lifting mechanism 884.

  The sheet material P sent in again is sandwiched between the double-sided roller 891 and the pinch roller 892 and conveyed. The sheet material P is guided by the guide 893 and conveyed. The double-sided paper conveyance path is configured to merge with the paper path at the time of U-turn conveyance after a predetermined amount. Therefore, the subsequent configuration and operation of the paper path are the same as those described above.

(F) Cleaning unit The cleaning unit 6 includes a pump 60 for cleaning the recording head 7, a cap 61 for suppressing the drying of the recording head 7, a blade 62 for cleaning the face surface around the nozzles of the recording head 7, and the like. It is composed of
The main drive of the cleaning unit is transmitted from the aforementioned AP motor 273. Basically, the one-way clutch 691 is provided so that the pump operates by rotation in one direction, and the blade 62 operation and the cap 61 elevating operation act by rotation in another direction.

  The pump 60 is configured to generate a negative pressure by squeezing two tubes 67 with a pump roller 68, and is connected from the cap 61 to the pump 60 through a valve 65 or the like. When the pump 60 is operated with the cap 61 in close contact with the recording head 7, unnecessary ink or the like is sucked from the recording head 7. A cap absorber 611 is provided in the cap 61 portion in order to reduce the ink remaining on the face surface of the head 7 after suction. For this reason, the ink remaining in the cap 61 is sucked in a state where the cap 61 is opened so that the ink remains stuck and does not cause any harmful effects. The waste ink sucked by the pump 60 is absorbed and held in a waste ink absorber 991 provided in a lower case 99 described later.

  A series of operations such as the blade 62 operation and the cap 61 elevating operation are controlled by a main cam 63 provided with a plurality of cams on the shaft. The cam and arm of each part are acted on the main cam to perform a predetermined operation. The position of the main cam 63 can be detected by a position detection sensor 64 such as a photo interrupter. When the cap 61 descends, the blade 62 moves perpendicularly to the scanning direction of the carriage 5 to clean the face surface of the recording head 7. Plural blades 62 are provided for cleaning the vicinity of the nozzles of the recording head 7 and for cleaning the entire face surface. Then, when it moves to the innermost position, the ink adhered to the blade 62 itself can be removed by contacting the blade cleaner 66.

  The drive transmission and control for opening and closing the valve 65 are performed by the paper discharge roller 40. By selecting the valve 65, it is possible to perform collective suction for all colors and individual suction for each color as required. The valve 1 detection is performed by the valve position detection sensor 651.

(G) Exterior part Each of the above-described units is incorporated in the chassis 11 and forms a mechanism part of the printer. The exterior is attached so that the circumference may be covered. The exterior mainly includes a lower case 99, an upper case 98, an access cover 97, a connector cover 96, a front cover 95, and a side cover 96.

  The front cover 93 is configured to be able to store the paper discharge tray 46 and is configured to close the paper discharge port when not in use. The open / closed state of the front cover 95 can be detected by a sensor (not shown).

  An access cover 97 is attached to the upper case 98 and is configured to be rotatable. A part of the upper surface of the upper case has an opening, and the ink tank 71 and the recording head 7 are configured to be exchangeable at this position. Further, the upper case 98 is provided with a door switch lever 981 for detecting opening / closing of the access cover, an LED guide 982 for transmitting / displaying LED light, a key switch 983 for acting on the SW of the board, and the like. Further, the paper feed tray 26 is rotatably attached to the upper case 98. When the paper feed unit is not used, the paper feed tray 26 is configured to be a cover of the paper feed unit if it is stored.

  Further, the upper case 98 and the lower case 99 are attached with elastic fitting claws. A connector cover 96 covers a portion in which the connector portion is provided.

  The side cover 93 is attached so as to cover the upper case 98 and the lower case 99 from the left and right.

  Next, when at least one of a plurality of encoder sensors according to the present invention is abnormal, details of carrying out a different conveyance control using a normal encoder sensor will be described with reference to FIGS.

  As shown in FIG. 4, the drive to the transport roller 36 transmits the rotational force of the transport motor 35 formed of a DC motor to a pulley 361 provided on the shaft of the transport roller 36 by a timing belt 39. A code wheel 362 on which markings are formed with a pitch of 150 to 300 lpi for detecting the amount of conveyance by the conveyance roller 36 is directly connected to the axis of the conveyance roller 36, and an encoder sensor 363 that reads the code wheel 362 is provided. The code wheel 362 is attached to the chassis 11 at an adjacent position. Then, the drive from the transport roller 36 is transmitted through the idler gear 45, whereby the paper discharge roller 40 is driven. Further, a code wheel 402 on which markings are formed at a pitch of 150 to 300 lpi for detecting the transport amount by the paper discharge roller 40 is directly connected on the shaft of the paper discharge roller 40, and an encoder sensor 403 that reads the code wheel 402 is connected thereto. It is attached to the chassis 11 at a position adjacent to the code wheel 402.

  First, the case where all of the plurality of encoder sensors 363 and 403 are normal will be described with reference to FIG. FIG. 5A shows the control area of the plurality of encoder sensors. Depending on the position of the rear end of the sheet material P, the encoder sensors 363 and 403 are switched or jointly, the conveyance control of the sheet material P is performed. The back end position of the sheet material P is detected by the PE sensor-lever 35, and the rear end position of the sheet material P is approximately 10 mm before the nip position between the transport roller 36 and the pinch roller 37. (1) Transport roller encoder sensor 363 is a control area. In this region, only the transport roller encoder sensor 363 performs control, transports a predetermined amount, and stops at a predetermined position.

  In the range where the rear end position of the sheet material P is approximately within 10 mm before and after the nip position between the conveyance roller 36 and the pinch roller 37, (2) the joint control area of the conveyance roller encoder sensor 363 and the discharge roller encoder sensor 403 is set. During this period, the outputs of both encoder sensors 363 and 403 are read, and the stop position is calculated from both position data. At this time, since the encoders 363 and 403 are misaligned, the time is multiplied and the minimum resolution is increased to the point where there is no influence on printing, and the positions of both encoders are corrected.

  Thereafter, when the rear end position of the sheet material P has passed the nip position of about 10 mm between the conveyance roller 36 and the pinch roller 37, (3) a control region of the paper discharge roller encoder sensor 403 is set. In this area, only the paper discharge roller encoder sensor 403 performs control, carries a predetermined amount, and stops at a predetermined position. Since the paper discharge roller 40 that directly conveys the sheet material P is controlled by the code wheel 402 and the paper discharge roller encoder sensor 403 that are directly connected to the paper discharge roller 40, it is possible to ensure high-precision conveyance accuracy. is there.

  Further, printing control in the encoder control area will be described with reference to FIGS. In the first control area by the transport roller encoder sensor 363, the transport roller 36 has a structure in which the surface of the metal shaft is coated with fine ceramic particles, and the outer diameter, the deflection, and the like can be configured with high precision. All nozzles of the head 7 are used, and three-pass multi-pass printing is performed so that one feed is 1/3 of that. And, in the control area by the paper discharge roller encoder sensor 403, the paper discharge roller 40 provides a rubber part such as EPDM on the metal shaft and polishes it, so that accuracy such as outer diameter and runout is obtained. In terms of configuration, the configuration of the paper discharge roller 36 is inferior. Therefore, in order to compensate for the accuracy, 3/4 nozzles of the recording head 7 are used, and 3 pass multi-pass printing is performed so that one feed is 1/3 (1/4 of all nozzles). ing.

  Next, control when an abnormality occurs in the paper discharge roller encoder sensor 403 will be described with reference to FIG.

  The configuration is the same as shown in FIG. Even if an abnormality occurs in the discharge roller encoder sensor 403, the drive to the discharge roller 40 is transmitted from the transport roller 36 to the discharge roller 40 via the idler gear 45, so that the discharge roller 40 is driven. There is no problem in itself.

  At the time of initializing the operation, the outputs of both encoder sensors 363 and 403 are checked at the same time to check whether there is any abnormality. Here, when it is found that the paper discharge roller encoder sensor 403 is abnormal, the control areas are changed as shown in FIG. First, the first (1) transport roller encoder sensor-control area does not change. The PE sensor lever 35 detects the rear end position of the sheet material P, and the control of the conveyance roller encoder sensor 363 is performed until the rear end position of the sheet material P is approximately a predetermined position before the nip position between the conveyance roller 36 and the pinch roller 37. It is an area. In this region, only the transport roller encoder sensor 363 performs control, transports a predetermined amount, and stops at a predetermined position.

  In the range where the rear end position of the sheet material P is approximately within 10 mm before and after the nip position between the conveyance roller 36 and the pinch roller 37, the common control region of the conveyance roller encoder sensor 363 and the discharge roller encoder sensor 403 is in the normal state described above. However, (2) only the transport roller encoder sensor 363 is controlled (rear end processing area). And it becomes an area | region where control that the rear end of the sheet | seat material P does not stop at a nip position is integrated.

  Thereafter, only the paper discharge roller 40 is driven from the position where the rear end position of the sheet material P has passed the nip position between the conveyance roller 36 and the pinch roller 37, but the paper discharge roller encoder sensor 403 is abnormal. (3) is a control region of the transport roller encoder sensor 363. Therefore, since the mechanical configuration of the pulley 361, the idler gear 45, and the paper discharge roller gear 404 is interposed up to the paper discharge roller 40, that amount becomes a factor that deteriorates the conveyance accuracy.

  The printing control in the encoder control area at that time will be described with reference to FIGS. 6B and 6C. The first (1) control region by the transport roller encoder sensor 363 does not change from the normal state, so that all nozzles of the recording head 7 are used, and a three-pass multi-pass that makes one-third of the feed one time. It consists of pass printing. Then, after the recording sheet P passes through the nip between the conveying roller 36 and the pinch roller 37, (3) the control area of the conveying roller encoder sensor 363 is used, and the recording head is used to ensure the conveying accuracy of the recording sheet P. The nozzles are squeezed to ¼, and three pass multi-pass printing is performed so that one feed is 1/3 (1/12 of all nozzles).

  According to the above configuration, when the paper discharge encoder sensor 403 out of the transport roller encoder sensor 363 and the paper discharge encoder sensor 403 is abnormal, a failure is caused by using the normal transport roller encoder sensor 363 for transport. It becomes possible to print without making it. Furthermore, by narrowing down the nozzles used and reducing the transport amount at one time, it is possible to secure the same image as usual although the printing speed is reduced.

(Second Embodiment)
In the above-described embodiment, the case where the paper discharge encoder sensor 403 has failed has been described. However, when the transport roller encoder sensor 363 has failed, printing is performed using only the paper discharge encoder sensor 403, and print control is performed accordingly. May be performed.

  Control when an abnormality occurs in the transport roller encoder sensor 363 will be described with reference to FIG.

  The configuration is the same as shown in FIG. Even if an abnormality occurs in the transport roller encoder sensor 363, the position of the transport roller 36 can be detected using the paper discharge roller encoder sensor 403.

  At the time of initializing the operation, the outputs of both encoder sensors 363 and 403 are checked at the same time to check whether there is any abnormality. Here, when it is found that the transport roller encoder sensor 363 is abnormal, the control area in each is changed as shown in FIG. First, the first transport roller encoder sensor 363 control area is the paper discharge roller sensor 403 control area. The rear end position of the sheet material P is detected by the PE sensor lever 35, and (1) the discharge roller encoder until the rear end position of the sheet material P is approximately a predetermined position before the nip position between the conveying roller 36 and the pinch roller 37. This is a control area of the sensor 403. In this area, only the paper discharge roller encoder sensor 363 performs control, carries out a predetermined amount, and stops at a predetermined position.

  In the range where the rear end position of the sheet material P is approximately within 10 mm before and after the nip position between the conveyance roller 36 and the pinch roller 37, the common control region of the conveyance roller encoder sensor 363 and the discharge roller encoder sensor 403 is normal in the above-described case. However, (2) only the discharge roller encoder sensor 403 is controlled. And it becomes an area | region where control that the rear end of the sheet | seat material P does not stop at a nip position is integrated.

  Thereafter, from the point where the rear end position of the sheet material P has passed the nip position between the conveying roller 36 and the pinch roller 37, (3) a control region of the paper discharge roller encoder sensor 403 is set. From here, it becomes the same as when the encoder sensor is normal. In this area, only the paper discharge roller encoder sensor 403 performs control, carries a predetermined amount, and stops at a predetermined position. Since the paper discharge roller 40 that directly conveys the sheet material P is controlled by the code wheel 402 and the paper discharge roller encoder sensor 403 that are directly connected to the paper discharge roller 40, it is possible to ensure high-precision conveyance accuracy. is there.

  The printing control in the encoder control area at that time will be described with reference to FIGS. 7B and 7C.

  In the first (1) control region by the paper discharge roller encoder sensor 403, the mechanical configuration of the pulley 361, the idler gear 45, and the paper discharge roller gear 404 is passed from the transport roller 36 to the paper discharge roller 40. This deteriorates the detection accuracy, and as a result, deteriorates the conveyance accuracy. Therefore, in order to ensure the conveyance accuracy of the recording sheet P, the number of nozzles used in the recording head is reduced to 3/4, and 3 passes of 1 pass (1/4 of all nozzles) is performed. It consists of multi-pass printing.

  After passing through the nip between the transport roller 36 and the pinch roller 37, (3) the control area of the paper discharge roller encoder sensor 403 becomes the same as that when the encoder sensor is normal, so the transport accuracy of the recording sheet P is improved. In order to ensure this, the number of nozzles used in the recording head is reduced to 3/4, and it is configured by 3-pass multi-pass printing so that one feed is 1/3 (1/4 of all nozzles).

  According to the above configuration, when the transport encoder sensor 363 out of the transport roller encoder sensor 363 and the paper discharge encoder sensor 403 is abnormal, a failure is caused by transporting using the normal paper discharge roller encoder sensor 403. It becomes possible to print without making it. Furthermore, by narrowing down the nozzles used and reducing the transport amount at one time, it is possible to secure the same image as usual although the printing speed is reduced.

  Other configurations and operations are the same as those in the above-described embodiment.

1 is a perspective view of a recording apparatus according to a first embodiment of the present invention. FIG. 3 is a perspective view of a mechanism unit of the recording apparatus according to the first embodiment of the invention. 1 is a cross-sectional view of a recording apparatus according to a first embodiment of the present invention. Explanatory drawing of the several encoder in 1st Example of this invention. Explanatory drawing of the control area | region and printing control at the time of multiple encoder normal in 1st Example of this invention. Explanatory drawing of the control area | region and printing control at the time of abnormality of the paper discharge roller encoder in 1st Example of this invention. Explanatory drawing of the control area | region at the time of conveyance roller encoder abnormality in 2nd Example of this invention, and printing control.

Explanation of symbols

28 Feed roller 281 Feed roller rubber 29 ASF sensor 30 Pinch roller holder 31 Pinch roller spring 32 PE sensor 321 PE sensor lever 33 Paper guide flapper 331 Bearing portion 34 Platen 342 Transport roller attachment portion 343 Chassis attachment shaft 344 Platen absorber 35 Conveyance motor 36 Conveyor roller 361 Pulley 362 Code wheel 363 Encoder sensor 37 Pinch roller 38 Bearing 381 Roller tension spring 39 Conveyor roller drive belt 40 Discharge roller 1
401 Paper discharge roller 1 rubber part 402 Code wheel 403 Encoder sensor 404 Paper discharge roller gear 41 Paper discharge roller 2
42 Spur
43 spur holder 44 spur spring 45 idler gear 46 discharge tray

Claims (5)

A recording apparatus that scans a recording head and records on a recording sheet,
A first conveying means disposed on the upstream side in the recording sheet conveying direction across the scanning area of the recording head;
A second conveying means disposed downstream in the recording sheet conveying direction;
Each of the first transport means and the second transport means is provided with a detection means for detecting the amount of rotation of each of the first transport means and the detection result of one of the detection means. A recording apparatus for transporting a recording sheet using the recording apparatus.   2. The recording apparatus according to claim 1, wherein the driving source of the first conveying unit and the second conveying unit are the same, and the driving force is transmitted from the first conveying unit to the second conveying unit by the transmitting unit.   The recording apparatus according to claim 1, wherein when the abnormality is detected, the amount of conveyance at one time is made smaller than usual in the whole area or a part of the area.   When the detection result of the detection unit provided in the second conveyance unit is abnormal and the detection result of the detection unit provided in the first conveyance unit is normal, the trailing edge of the recording sheet is moved from the first conveyance unit. The recording apparatus according to claim 2, wherein the conveyance amount at one time is smaller than usual from the vicinity where the ink is removed.   If the detection result of the detection means provided in the first transport means is abnormal and the detection result of the detection means provided in the second transport means is normal, the transport amount of one time in all areas is less than normal. 4. The recording apparatus according to claim 2, wherein the recording apparatus is made small.

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