Source: http://www.google.com/patents/US7182336?dq=7,453,150
Timestamp: 2017-06-24 08:04:13
Document Index: 398136985

Matched Legal Cases: ['art 2', 'art 2', 'art 2', 'art 2', 'art 25', 'art 25', 'art 26', 'art 26', 'art 26', 'art 26', 'art 26', 'art 43', 'art 38', 'art 16', 'art 16', 'art 26', 'art 26']

Patent US7182336 - Paper feeder, recording apparatus, and method of detecting a position of a ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsA paper feed unit includes a hopper on which sheets are stacked and which is turned around a rotation shaft. The hopper is turned to move apart from or move to a paper feed roller. The paper feed unit has three modes: a large release mode in which the hopper is turned to be most apart from the paper...http://www.google.com/patents/US7182336?utm_source=gb-gplus-sharePatent US7182336 - Paper feeder, recording apparatus, and method of detecting a position of a terminal edge of a recording material in the recording apparatusAdvanced Patent SearchTry the new Google Patents, with machine-classified Google Scholar results, and Japanese and South Korean patents.Publication numberUS7182336 B2Publication typeGrantApplication numberUS 10/980,245Publication dateFeb 27, 2007Filing dateNov 4, 2004Priority dateAug 28, 2001Fee statusPaidAlso published asCN1220590C, CN1401499A, DE60212529D1, DE60212529T2, DE60225359D1, EP1288144A2, EP1288144A3, EP1288144B1, EP1621494A1, EP1621494B1, US6880822, US7182337, US20030057635, US20050062215, US20050062216Publication number10980245, 980245, US 7182336 B2, US 7182336B2, US-B2-7182336, US7182336 B2, US7182336B2InventorsToru Fukushima, Kazuhisa Kawakami, Masafumi Furuyama, Yoji Sasai, Norihiro Yamashita, Yoichi Kobayashi, Hirotomo TanakaOriginal AssigneeSeiko Epson CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (15), Referenced by (18), Classifications (28), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetPaper feeder, recording apparatus, and method of detecting a position of a terminal edge of a recording material in the recording apparatus
US 7182336 B2Abstract
A paper feed unit includes a hopper on which sheets are stacked and which is turned around a rotation shaft. The hopper is turned to move apart from or move to a paper feed roller. The paper feed unit has three modes: a large release mode in which the hopper is turned to be most apart from the paper feed roller, a non-release mode in which the printing sheet is abutted against the paper feed roller, and a small release mode in which the printing sheet is slightly separated from the paper feed roller, and is at a medium level between the above two modes. When a paper feeding job is still present, a state that the uppermost printing sheet is slightly separated from the paper feed roller is retained by the small release mode, whereby a swing range of the hopper is minimized.
1. A terminal edge position detecting method for detecting a terminal edge position of a recording sheet in a recording apparatus for recording an image on a recording sheet while the recording sheet is transported in a fixed direction at a predetermined transportation quantity, comprising the steps of:
computing the terminal edge position of the recording sheet by correcting the detected position of the terminal edge detected by the sheet detector with the detect delay error transportation quantity.
2. A terminal edge position detecting method according to claim 1, wherein the detect delay error transportation quantity is given by the following equation
y: detect delay error transportation quantity, and
3. A terminal edge position detecting method according to claim 1, wherein the transporting speed of the recording sheet at the time of the passage of the terminal edge is computed from an encoder signal output from an encoder device which detects a rotational displacement quantity of a transport drive roller for transporting the recording sheet.
4. A terminal edge position detecting method for detecting a terminal edge position of a sheet which is transported at a predetermined transportation quantity, comprising the steps of:
detecting a passage of the terminal edge of the sheet and obtaining a detected position of the terminal edge of the sheet by a sheet detector which detects the sheet by contacting therewith;
acquiring a transporting speed of the sheet at a time point of passage of the terminal edge of the sheet;
computing a detect delay error transportation quantity of the sheet which is generated during a detect delay time of the sheet detector based on the transporting speed of the sheet; and
computing the terminal edge position of the sheet by correcting the detected position of the terminal edge detected by the sheet detector with the detect delay error transportation quantity.
5. A terminal edge position detecting method according to claim 4, wherein the detect delay error transportation quantity is given by the following equation:
where x: transporting speed of the sheet at the time point that the sheet detector detects the passage of the terminal edge of the sheet,
6. A terminal edge position detecting method according to claim 4, wherein the transporting speed of the sheet at the time of the passage of the terminal edge is computed from an encoder signal output from an encoder device which detects a rotational displacement quantity of a transport drive roller for transporting the sheet.
7. A terminal edge position detecting method for detecting a terminal edge position of a sheet, the method comprising:
transporting the sheet in a fixed direction;
contacting a terminal edge of the sheet with a detector to detect a position of the sheet;
determining a speed of the sheet when the terminal edge of the sheet passes the detector;
computing a delay amount between an instant that the terminal edge of the sheet leaves the detector and an instant that the detector detects passage of the terminal edge of the sheet; and
computing an actual position of the sheet by adjusting the position which is detected by the detector with the delay amount which is computed.
8. A terminal edge position detecting method according to claim 7, wherein the delay amount is calculated with the following formula:
where x is a speed of the sheet when the detector detects the passage of the terminal edge of the sheet,
9. A terminal edge position detecting method according to claim 7, wherein the speed of the sheet when the terminal edge passes the detector is computed from an encoder signal output from an encoder device which detects a rotational displacement quantity of a transport drive roller for transporting the sheet.
This is a divisional of application Ser. No. 10/228,258 filed Aug. 27, 2002, now U.S. Pat. No. 6,880,822 which is hereby incorporated by reference, and which claims benefit of Japanese Application 2001-257406 filed Aug. 28, 2001; and Japanese Application 2001-261998 filed Aug. 30, 2001.
An overall construction of an ink jet printer according to a first embodiment of the present invention will be described with reference to FIGS. 1 through 4. FIG. 1 is a perspective view showing an outward appearance of a main body of the ink jet printer (referred to as a printer”. FIG. 2 is an exploded, perspective view showing the same. FIG. 3 is a sectional side elevation view showing the same. FIG. 4 is a front view showing the same.
Referring to FIGS. 1 and 2, a main body of a printer 100 is divided into a plurality of units. Those units are composed into the main body. In the figure, reference numeral 1 designates a paper feed unit as a sheet feeding device capable of feeding a printing sheet or paper sheet P (see FIG. 3) as a recording material or a rolled sheet (not shown). Reference numeral 120 designates a carriage unit 120 provided with a carriage having an ink jet recording head 124 (see FIG. 3). Reference numeral 160 designates a transport unit 160 for transporting a printing sheet P. Reference numeral 180 designates an ink system unit for doing maintenance of the ink jet recording head 124. The main body of the printer 100, as shown in FIG. 2, is divided into four units as shown in FIG. 2, and those four units are composed into the main body. In the present embodiment, a carriage unit 120 and an ink system unit 180 are coupled to the upper part and the right side part (the right side in FIG. 4) of the transport unit 160. The paper feed unit 1 is coupled to the rear side part of the carriage unit 120. As a result, the four units are composed into a single unit.
A sheet transporting path in the printer 100 will be described with reference to FIG. 3. In the description to be given hereunder, the left side (the rear side of the printer 100) in FIG. 3 will be “upstream side” of transportation, and the right side (the front side of the printer 100) in FIG. 3 will be referred to as “downstream side” of transportation. The printer 100 is equipped with the hopper 6. A stack of printing sheets P as cutform papers are put on the hopper 6, while being inclined. The hopper 6 is supported by a rotation shaft 6 a (see FIG. 7) located in an upper part, and rotatable around the rotation shaft clockwise and counterclockwise. When the hopper is rotated, its lower part moves to a paper feed roller 3 and to be pressed against the same, and moves apart from the paper feed roller. The hopper 6 includes a movable guide 4, which is slidable in the width direction of the printing sheet P (see FIG. 1), and cooperates with a fixed guide 5 (see FIG. 1) to guide the side ends of the printing sheets P stacked. The uppermost sheet of the stacked printing sheets P is fed to the downstream side in a manner that the hopper 6 is pressed against the paper feed roller 3 and in a pressing state, the paper feed roller 3 is rotated. The paper feed roller 3 is shaped like D when viewed from side. In a print mode of the recording apparatus, a flat part of the paper feed roller is put to face the printing sheet P (its state of FIG. 3). This state of the paper feed roller prevents a transport load to be imparted on the printing sheet P from being generated.
The hopper 6, movable guide 4, fixed guide 5 and paper feed roller 3 are contained in the paper feed unit 1 shown in FIGS. 1 and 2. A base of the paper feed unit 1 is constructed with a sheet feeding unit frame 2 having a column-like right mounting part 2 a and a column-like left mounting part 2 b, which stand erect on both sides of the hopper 6 as shown in FIG. 2. A paper feed roller shaft 3 a serving as the rotation shaft of the hopper 6 and the paper feed roller 3, and the like are provided on the sheet feeding unit frame 2. The paper feed unit 1 is coupled to the rear side of the carriage unit 120 at the upper parts of the right mounting part 2 a and the left mounting part 2 b. The further detail of the paper feed unit 1 will be described later.
In FIG. 2, the sheet-discharge frame 130 is mounted on the carriage unit 120. The sheet-discharge frame 130 may be mounted on the carriage unit 120, and if necessary may be mounted on the transport unit 160. That is, it may be contained in any of those units.
A variation range of a contact angle α in the embodiment, viz., a disposing position of the rotation shaft 6 a which determines a swing angle of the hopper 6 and a dimension of the hopper 6 in the feeding direction (a longitudinal size of the printing sheet P) are selected as below. An angle developed when the hopper 6 swings from a state that it is most apart from the paper feed roller 3 to a state that the uppermost printing sheet P is abutted on the paper feed roller 3, varies depending on an amount of the printing sheets P stacked on the hopper 6. As a result, a contact angle α at which the tip of the printing sheet P comes in contact with the separation pad 8, also varies. FIG. 9A shows a contact angle αmax when a maximum number of printing sheets P set on the hopper, and FIG. 9B shows a contact angle αmin when an approximately minimum number of printing sheets P set on the hopper. As seen from the figure, as the number of printing sheets P as set is larger, the contact angle α becomes larger. In FIGS. 9A and 9B, character P1 designates the uppermost printing sheet, and P2, a second printing sheet subsequent to the uppermost printing sheet P1.
When in FIG. 9A, the contact angle αmax is larger than a maximum value α1 of the contact angle allowing the uppermost printing sheet P1 to pass therethrough, the uppermost printing sheet P1 to be fed is caught by the separation pad 8 and there is a chance that it is not fed. Conversely, when the contact angle αmin is smaller than a minimum value of the contact angle capable of preventing the double feeding of the printing sheet P, the second printing sheet P2 (a plurality of printing sheets P including the second printing sheet P2 and the subsequent ones) is nipped between the uppermost printing sheet P1 to be fed and the separation pad 8, possibly causing the double feeding of the printing sheets. In the embodiment, the position at which the rotation shaft 6 a of the hopper 6 is disposed and the size of the hopper 6 in the paper feeding direction are selected so as to satisfy a relation of α2≦α≦α1 irrespective of the number of printing sheets P stacked on the hopper 6. Accordingly, the hopper is capable of always feeding the sheets since the contact angle αmax does not exceed the upper limit α1, and the αmin does not fall below the lower limit α2. In the embodiment, the length of the hopper 6 in the paper feeding direction is about 130 mm, and the swing angle of the hopper 6 is 10°. This swing angle does not contain a swing angle 2° of the hopper 6, which is developed till a maximum number of printing sheets P are set in the hopper, and the uppermost printing sheet P is abutted on the paper feed roller 3.
The paper feed auxiliary roller 15 is shaped like D when viewed from side, like the paper feed roller 3. A diameter of the paper feed auxiliary roller is equal to that of the paper feed roller 3. In the paper feed auxiliary roller, a flat part of the D shape is more cut than that in the paper-feed roller 3. This is best illustrated in FIG. 8A. As shown, the flat part of the paper feed auxiliary roller 15 is closer to the center of the rotation (viz., to the paper feed roller shaft 3 a) than that of the paper feed roller 3 (the diameter of the paper feed roller 3 is 48 mm, and that of the paper feed auxiliary roller 15 is 4 mm).
The reason for this will be described below. When the printing sheet P is transported (in a print mode), the flat part of the paper feed roller 3 (and paper feed auxiliary roller 15) is opposed to the printing sheet P as shown in FIG. 7 in order to lessen a sheet transport load (a rotation load of the transport drive roller 162 (see FIG. 3). A sheet return lever 12 is disposed under the paper feed roller 3 as shown in FIG. 8B (see also FIG. 7). The printing sheet P, as shown in FIG. 8B, is slightly bent when viewed in the width direction by the paper feed roller 3 and the sheet return lever 12. In this case, if a configuration of the paper feed auxiliary roller 15 is the same as of the paper feed roller 3, the printing sheet P is outward curved as indicated by a broken line in FIG. 8B. As a result, the sheet transport load disadvantageously increases by a rigidity of the printing sheet P and the friction associated with the paper feed roller 3, paper feed auxiliary roller 15 and sheet return lever 12. To cope with this, as described above, the configuration of the paper feed auxiliary roller 15 is different from that of the paper feed roller 3, whereby an unnecessary bending is not imparted to the printing sheet P and the sheet transport load increase is not caused.
A second function of the paper feed auxiliary roller 15 is a function as a “twist restricting member” for restricting a twist of the paper feed roller shaft 3 a. The paper feed roller shaft 3 a serves as a drive force transmission shaft which receives a rotational force from the transmission gear device 17 provided on the left side of the printer (the left side in FIG. 6) and transmits the drive force to the hopper release device to be given later, provided on the right side of the printer (the right side in FIG. 6). Accordingly, when the drive force is transmitted to the hopper release device or when the printing sheet is fed by the paper feed roller 3, a load is imparted to the paper feed roller shaft 3 a. As a result, a twist is caused in the paper feed roller shaft 3 a. When a twist is caused in the paper feed roller shaft 3 a, a phase shift occurs in the rotating operation of the paper feed roller 3 or in the operation of the hopper release device fed with the drive force. In this state, it is impossible to secure a normal paper feeding operation and a normal drive force transmission. Particularly, the paper feed roller 3 is located at a position on the paper feed roller shaft 3 a, which is deviated to the side remote from the shaft end (the left side in FIG. 6) which receives a rotational force. Accordingly, it more easily receives the influence of the twit.
As described above, the hopper release device is installed on the right side surface (this side in FIG. 5: the right side in FIG. 6) of the paper feed unit 1. A power transmission gear 11 is mounted on the right side end of the paper feed roller shaft 3 a in FIG. 5. The power transmission gear 11 is in mesh with a gear part 25 (see FIG. 12B) formed on the rear side of the rotary cam 20, which is rotatably supported on a rotation shaft 21, whereby the rotary cam 20 is driven to rotate. Exactly, the rotary cam 20 rotates with rotation of the paper feed roller 3. The hopper release device does not include a drive source, and hence, is low in cost. The power transmission gear 11 directly engages with the rotary cam 20, and the number of teeth of the power transmission gear 11 is equal to that of the gear part 25. Accordingly, the paper feed roller 3 is rotated clockwise by one turn, then the rotary cam 20 is rotated counterclockwise by one turn.
The guide slopes 24 a to 24 c function to guide the cam lever 30 located at a non-cam part 26 (to be described later) to the guide face 23 a and the fan-shaped guide faces 23 b to 23 e. The guide slope 24 a, as shown in FIG. 5, gradually rises while turning clockwise around the rotary cam 20; it has a height being uniform in the radial direction (in FIG. 12B the left side corresponds to a high side of it); it is connected at the inner side to the fan-shaped guide face 23 e at substantially the same level; it is connected at the central part as radially viewed to the guide slope 24 b inclined to the fan-shaped guide faces 23 b to 23 d, which is located at a position lower than the guide face 23 e; and it is connected at the outer periphery to the guide slope 24 c inclined to the guide face 23 a. The non-cam part 26 formed with a flat disc surface (within a region (3) in FIG. 12A) is provided adjacent to the fan-shaped cams 22 a to 22 e. The non-cam part 26 does not restrain the cam lever 30 in the radial direction of the rotary cam 20. Accordingly, when the rotary cam 20 is turned (counterclockwise in FIG. 12A) to enter the region of the non-cam part 26, the cam lever 30 being in engagement with the fan-shaped cam 22 a located on the radially outermost side, is displaced to the center of the rotation of the rotary cam 20 from its state till the uppermost printing sheet P is abutted against the paper feed roller 3 under the urging by the compression coiled spring 7 shown in FIG. 7. Conversely, when the rotary cam 20 is turned clockwise in FIG. 12A, the cam lever 30 which is in the area of the non-cam part 26 is guided from its state to the outer peripheral surface of the fan-shaped cam 22 a located on the radially outermost side while being guided by a cam surface smoothly continuous to the outer peripheral surface of the fan-shaped cam 22 a. Referring to FIGS. 13A and 13B, the cam lever holder 35 takes an arm-like form including an arm 39 a extended from a shaft hole 40 through which a rotation shaft 36 (see FIG. 5) is made to pass, and another arm 39 b extending from the arm 39 a in an upward direction. And it is mounted on the sheet feeding unit frame 2 in a state that it is turned around the center of the shaft hole 40. A spring hooking part 43 is provided on the cam lever holder 35. The sheet feeding unit frame 2 also includes a similar spring hooking part (not shown) A tension coil spring 37 is stretched between those spring hooking parts (see. FIG. 5). The tension coil spring 37 generates such a spring force as to turn the cam lever holder 35 clockwise in FIG. 13, and with provision of the tension coil spring, it is operated in a state that the protruded part 38 is always in contact with the release bar 16.
In FIG. 13A, when the cam lever holder 35 is turned clockwise in the figure, the release bar 16 (third shaft part 16 c) is turned counterclockwise, so that the hopper 6 is turned in such a direction as to move apart from the paper feed roller 3. At this time, the cam lever holder 35 turns the hopper 6 while resisting the spring force of the compression coiled spring 7 (see FIG. 7). When the cam lever holder 35 is turned counterclockwise in the figure, the release bar 16 (third shaft part 16 c) is turned clockwise, so that the hopper 6 is turned in such a direction as to be pressed against the paper feed roller 3. In this case, the release bar 16 and the cam lever holder 35 are turned by a spring force of compression coiled spring 7 (see FIG. 7).
Engaging operations of the rotary cam 20, cam lever 30 and cam lever holder 35 thus constructed will be described in brief. In FIG. 12A, as indicated by a phantom line and designated reference numeral 30, the cam lever is in pressing contact with the outer peripheral surface of the fan-shaped cam 22 a. A case where the rotary cam 20 is turned by one turn (360°) from this state will be described.
When the rotary cam 20 is further turned counterclockwise in FIG. 12A, the cam lever 30 enters the cam lever guide part (region (3)), and starts its engagement with the guide slope 24 a. At this time, the cam lever 30 swings in the axial direction of the rotary cam 20 (8 see FIG. 12B)), while it is not displaced in the radial direction of the rotary cam 20, and is guided to one of the fan-shaped guide face 23 e, guide slope 24 b (then, to the fan-shaped guide faces 23 b to 23 d), and guide slope 24 c (then, to the guide face 23 a).
As described above, a position as viewed in the radial direction of the rotary cam 20 at which the cam lever 30 is present varies depending on the amount of printing sheets P stacked on the hopper 6. The place where the cam lever 30 is to be guided, i.e., one of the fan-shaped guide face 23 e, guide slope 24 b (then, to the fan-shaped guide faces 23 b to 23 d), and guide slope 24 c (then, to the guide face 23 a), depends on the amount of stacked printing sheets P. Accordingly, when the amount of the stacked printing sheets P is small, the cam lever 30 is guided to the fan-shaped guide face 23 e. When the amount of the stacked printing sheets P is large, the cam lever 30 is guided to the guide slope 24 c (then, to the guide face 23 a).
When the rotary cam 20 is further turned, the cam lever 30 moves from one of the guided guide face 23 a and the fan-shaped guide face 23 b, viz., the current position as viewed in the radial direction on the rotary cam 20, and climbs on the outer periphery of the fan-shaped cam (fan-shaped cams 22 a to 22 e) which is closest to the outer periphery. In other words, the cam lever 30 is slightly displaced in the radial direction of the rotary cam 20 (from the center of rotation of the rotary cam 20 to the outer periphery), and the cam lever holder 35 is slightly turned clockwise in FIG. 13A. As a result, the hopper 6 is slightly swung in such a direction as to move apart from the paper feed roller 3. And, of the printing sheets P having been abutted on the paper feed roller 3, the uppermost printing sheet P is slightly separated from the paper feed roller 3 (in free state).
To being with, at the start of paper feeding, the cam lever 30 is put on the fan-shaped cam 22 a. The hopper 6 is at the largest distance from the paper feed roller 3 (FIG. 15A). The paper feed unit 1 is at a rest state allowing the printing sheet P to be set on the hopper in such a state of the hopper. When the paper feed roller 3 is normally rotated from that state for the purpose of paper feeding, the rotary cam 20 normally rotates counterclockwise in the figure. In turn, the cam lever 30 moves out of the fan-shaped cam 22 a, enters the region of the non-cam part 26 (region (3) (FIG. 16B), and the printing sheet P set on the hopper 6 is abutted against the paper feed roller 3 (FIG. 16A). In other words, the hopper release device executes the non-release mode (segment “a” in FIG. 14). And, with rotation of the paper feed roller 3, the feeding of the uppermost printing sheet P starts.
When the paper feed roller 3 is normally rotated, the cam lever 30 climbs from the guide face 23 c onto the outer periphery of the fan-shaped cam 22 c (FIG. 8B), and the hopper 6 slightly turns in such a direction as to move apart from the paper feed roller 3 (FIG. 18A). As a result, the printing sheet P is slightly separated from the paper feed roller 3 (FIG. 9A). In other word, the hopper release device executes the hopper release mode (segment “d” in FIG. 14).
And, the paper feed roller 3 rotates one turn (360°), and stops its rotation when the flat part of the paper feed roller, which is shaped like D when viewed from side, is opposed to the separation pad 8, to set up a state that no transport load is imparted to the printing sheet P which is under printing (transported). And, it waits till the feeding of the next printing sheet P starts (FIGS. 19A and 19B) (segment “e” in FIG. 14). Exactly, when a paper feeding job for the next printing sheet P and the subsequent ones is left, the hopper release device does not execute the large release mode which sets the hopper 6 at a position farthest from the paper feed roller 3, after the end of feeding of one printing sheet P, but executes the small release mode after the feeding operation of the printing sheet P. As a result, the uppermost printing sheet P is slightly separated from the paper feed roller 3. And, in feeding the next printing sheet P, the hopper 6 is able to abut the printing sheet P against the paper feed roller 3 by its slight turn.
When the printing operation completely ends, and a paper feeding job for the subsequent printing sheets P is not present, the hopper release device executes the large release mode and enters a rest mode. More exactly, after the segment “e” in FIG. 14 terminates (the printing operation ends), the hopper release device enters a control phase of a segment “f”. In the segment “f”, the paper feed roller 3 is normally rotated; the cam lever 30 is moved out of the fan-shaped cam 22 c, and it is guided to the non-cam part 26 (FIG. 20B); the paper feed roller 3 is reversely rotated from its state; the cam lever 30 is guided to the outer periphery surface of the fan-shaped cam 22 a (FIG. 21B); and the hopper 6 is turned to a position farthest from the paper feed roller 3. That is, the hopper release device executes the large release mode (FIGS. 22A and 22B).
A sheet-discharge drive roller 55 and a sheet-discharge follower roller 56 are provided for a device for discharging a recorded printing sheet P. The sheet-discharge drive roller 55 is rotated by a rotational drive force of a stepping motor or the like, and with rotation of the sheet-discharge drive roller 55, the printing sheet P is discharged in the sub-scan direction Y. A plurality of sheet-discharge follower rollers 56 are provided. Each sheet-discharge follower roller 56 has teeth formed around the periphery. The tip of each tooth is acute in shape so that it comes in point contact with the recording surface. Thus, each sheet-discharge follower roller 56 is a roller equipped with teeth. Those transport follower rollers are driven by a driving force, which is weaker than a drive force of the transport follower roller 54 by the sheet-discharge drive roller 55. When the printing sheet P is discharged with rotation of the sheet-discharge drive roller 55, those follower rollers come in contact with the printing sheet P and are rotated following the rotation of the printing sheet P.
FIG. 25 is a side view showing a key portion of an ink jet printer 50 of the present embodiment, in particular, a structure including an encoder 71 and its vicinal structure.
In the figure, an encoder period (μs) is computed using an encoder signal output from the sheet detector 63, and a transporting speed (ips) is computed using the computed encoder period. The computed transporting speed is rounded off in the unit of 1.5 ips. A detect delay error transportation quantity caused when the terminal edge of the printing sheet P passes the sheet detector 63 at the transporting speed in the unit of 1.5 ips, is expressed by a correction quantity (mm) corresponding to a detect offset of the terminal edge of the printing sheet P and a number of pulses (1/1440 dpi) of an encoder signal corresponding to the correction quantity of distance.
From the encoder period (μs) at a time point at which the sheet detector 63 detects passage of the terminal edge of the printing sheet P, the transporting speed (ips) of the printing sheet P at that time is calculated. A correction quantity for the transporting speed is computed by using the equation (1). The number of pulses of the encoder signal corresponding to the computed correction quantity (mm) are added to a transportation quantity of the printing sheet P stored in the recording control unit 101. In this way, the offset of the terminal edge of the printing sheet P as detected by the sheet detector 63 can be corrected exactly. The recording control unit 101 stores the table shown in FIG. 29, for example, as a data table. At a time point that the terminal edge of the printing sheet P passes the sheet detector 63, viz., the electrical contact of the sheet detector 63 is put to an off state, it computes an encoder period from the encoder signal output from the encoder device 71, and adds the computed one to a transportation quantity of the printing sheet P as a count of the number of pulses (1/1440 dpi) corresponding to the correction quantity (mm) corresponding to the encoder period (μs). By so doing, it can obtain a necessary correction quantity of the terminal edge of the printing sheet P.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS5186449 *Jan 13, 1992Feb 16, 1993Mita Industrial Co., Ltd.Sheet feeder unitUS5197726 *Jun 10, 1992Mar 30, 1993Fuji Xerox Co., Ltd.Sheet feederUS5582399 *Apr 14, 1995Dec 10, 1996Brother Kogyo Kabushiki KaishaSheet feeding device having sheet edge sensorUS5738348Dec 26, 1995Apr 14, 1998Seiko Epson CorporationSheet feederUS5848784 *Nov 28, 1997Dec 15, 1998Unisys Corp.Document separation apparatusUS5882130 *Oct 16, 1997Mar 16, 1999Seiko Epson CorporationPaper detection device for printerUS5893556Jun 6, 1996Apr 13, 1999Seiko Epson CorporationPrinter sheet feederUS5944430Sep 25, 1997Aug 31, 1999Samsung Electronics Co., Ltd.Automatic sheet feeder of an ink-jet printer and method for feeding a sheet of paperUS6095703Oct 31, 1997Aug 1, 2000Canon Kabushiki KaishaImage recording apparatus utilizing serial recording head and sheet feed and image recording method thereforUS6102392 *Aug 4, 1998Aug 15, 2000Bdt Buro - Und Datentechnik, Gmbh & Co. KgArrangement for the automatic and continuous adaptation of the document acceptance rate to the document output rate of document output devicesUS6142467Jan 12, 1998Nov 7, 2000Nec CorporationSheet feeder having an intermittent coupling memberUS6330424Nov 21, 2000Dec 11, 2001Lexmark International, Inc.Method and apparatus for minimizing the open loop paper positional error in a control system for an electrophotographic printing apparatusUS6354586Sep 1, 2000Mar 12, 2002Brother Kogyo Kabushiki KaishaSheet feederUS6755414 *Aug 24, 2001Jun 29, 2004Kabushiki Kaisha Nippon ConluxPaper sheet feederUS20010019192Feb 22, 2001Sep 6, 2001Wei-Feng YenAutomatic paper feeding system* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS7404558 *Jun 7, 2006Jul 29, 2008Canon Kabushiki KaishaSheet supplying device and sheet processing device using detecting leverUS7494120 *Jun 20, 2006Feb 24, 2009Funai Electric Co., Ltd.Image generating apparatusUS7556253 *Oct 5, 2007Jul 7, 2009Foxlink Image Technology Co., Ltd.Auto document feederUS7655830Aug 5, 2005Feb 2, 2010The Procter & Gamble Co.Superabsorbent polymer particles comprising functionalizers and method of making themUS8011657 *Jul 27, 2009Sep 6, 2011Kyocera Mita CorporationSheet transport device and image forming apparatus employing the sameUS8317193 *Jun 16, 2011Nov 27, 2012Canon Kabushiki KaishaSheet conveying apparatus and image forming apparatusUS8752829 *Jan 17, 2013Jun 17, 2014Hewlett-Packard Development Company, L.P.Rotatable and translatable mechanical flagUS9599171Mar 18, 2015Mar 21, 2017Canon Kabushiki KaishaOne-way clutch and sheet feeding rollerUS20060025734 *Jul 15, 2005Feb 2, 2006The Procter & Gamble CompanySuperabsorbent polymers comprising direct covalent bonds between polymer chain segments and method of making themUS20060030829 *Aug 5, 2005Feb 9, 2006The Procter & Gamble CompanySuperabsorbent polymer particles comprising functionalizers and method of making themUS20060175748 *Feb 3, 2006Aug 10, 2006Canon Denshi Kabushi KaishaSheet conveyance apparatus and image reading apparatusUS20060284362 *Jun 7, 2006Dec 21, 2006Canon Kabushiki KaishaSheet supplying device and sheet processing deviceUS20070040321 *Jun 20, 2006Feb 22, 2007Funai Electric Co., Ltd.Image generating apparatusUS20090043005 *Oct 3, 2008Feb 12, 2009The Procter & Gamble CompanySuperabsorbent Polymers Having Radiation Activatable Surface Cross-Linkers and Method of Making ThemUS20090091076 *Oct 5, 2007Apr 9, 2009Foxlink Image Technology Co., Ltd.Auto document feederUS20100019439 *Jul 27, 2009Jan 28, 2010Kyocera Mita CorporationSheet transport device and image forming apparatus employing the sameUS20120001382 *Jun 16, 2011Jan 5, 2012Canon Kabushiki KaishaSheet conveying apparatus and image forming apparatusUS20160272447 *Mar 14, 2016Sep 22, 2016Canon Kabushiki KaishaSheet detecting device and image forming apparatus* Cited by examinerClassifications U.S. Classification271/265.01, 271/264International ClassificationB65H1/08, B65H3/06, B65H1/14, B65H7/02Cooperative ClassificationB65H2511/24, B65H2513/10, B65H2557/20, B65H2553/61, B65H2301/42344, B65H3/0607, B65H2511/514, B65H2557/61, B65H2403/512, B65H2557/24, B65H3/0661, B65H2701/1313, B65H7/02, B65H2553/612, B65H2601/322, B65H2513/511, B65H2557/60, B65H1/022European ClassificationB65H1/02B, B65H3/06A, B65H7/02, B65H3/06LLegal EventsDateCodeEventDescriptionJul 28, 2010FPAYFee paymentYear of fee payment: 4Jul 30, 2014FPAYFee paymentYear of fee payment: 8RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services