Patent Grant
7959147
The present application claims priority from Japanese Patent Application No. 2006-352870, which was filed on Dec. 27, 2006, the disclosure of which is herein incorporated by reference in its entity.
1. Field of the Invention
The present invention relates to a sheet feeding apparatus that supplies a sheet from a sheet holding portion into a feed path, and particularly to a sheet feeding apparatus in which a feeder roller disposed in a feed path and a pickup roller disposed in a sheet holding portion are driven by a single driving source.
2. Description of Related Art
For instance, there is known a sheet feeding apparatus disposed in an inkjet printer and feeding a sheet from a sheet supply tray to a sheet catch tray along a feed path. The inkjet printer includes a recording head and records an image on the sheet supplied from the sheet supply tray by ejecting ink droplets from the recording head onto the sheet. The sheet is supplied from the sheet supply tray into the feed path and then fed along the feed path, by operation of two rollers that may be respectively called pickup roller and feeder roller. To the two rollers, a driving torque or a rotary motion of a motor as a driving source is transmitted. To transmit the driving torque from the motor to each of the two rollers, a transmission mechanism constituted by a combination of a gear, a timing belt, and/or others is employed.
The pickup roller operates to supply the sheet, that is, to feed out the sheet from the sheet supply tray into the feed path. The feeder roller operates to feed the sheet along the feed path. The required properties are different between the pickup roller and the feeder roller. For instance, a required precision in a speed at which the sheet is supplied or fed, and whether a deskew capability is required or not, are different between the pickup roller and the feeder roller. Hence, the pickup roller and the feeder roller are controlled to rotate differently from each other. There is known an arrangement for giving a driving force to each of the two rollers which are controlled to differently rotate, where a driving source is provided for each of the two rollers. There is also known an arrangement for a printer where a driving torque is transmitted from a single driving source to a plurality of driven portions, as disclosed in JP-A-3-272880. Further, JP-A-61-149379 and JP-A-60-145873 disclose an arrangement for rotating one of two rollers depending on a direction in which a driving source is rotated, by use of a one-way clutch or a planetary gear.
With respect to an image recording apparatus such as an inkjet printer, there is a demand for downsizing of the apparatus and speed-up of image recording. To meet the demand for downsizing, the sheet supply tray is downsized or reduced in thickness. Further, a guide is disposed on the sheet supply tray such that the position of the guide is variable on the sheet supply tray so that sheets in a variety of sizes, e.g., sheets in A4, B5 and legal sizes and postcard, can be selectively placed or set on the sheet supply tray. On the other hand, sometimes it is desired to include in an image recording apparatus another sheet supply tray on which a large stack of sheets of a kind that is frequently used, such as of A4 size, can be set. This sheet supply tray for holding a large stack of sheets will be hereinafter referred to as “sheet supply cassette”.
To meet the demand for the speed-up of image recording, there has been proposed an image recording apparatus in which the mode of sheet feeding is selectable, that is, one of a normal feeding mode and a high-speed feeding mode is selected. When the normal feeding mode is selected, image recording is performed to sheets that are one by one supplied into the feed path at a normal speed. When the high-speed feeding mode is selected, on the other hand, image recording is performed to sheets that are supplied into the feed path with a distance between each two sheets consecutively fed being reduced.
The image recording apparatus including the sheet supply cassette on which a large stack of sheets can be set necessarily further includes a transmission mechanism for transmitting a driving torque from a motor as a driving source to another pickup roller corresponding to the sheet supply cassette. On the other hand, the image recording apparatus capable of making a selection between the normal feeding mode and the high-speed feeding mode includes two transmission mechanisms for transmitting driving torques of two motors, respectively, namely, a first transmission mechanism for transmitting to the pickup roller a driving torque of a first motor that is for the normal feeding mode, and a second transmission mechanism for transmitting to the same pickup roller a driving torque of a second motor that is for the high-speed feeding mode.
It is often the case that an image recording apparatus of high-end model is equipped with the sheet supply cassette and the high-speed feeding mode as standard settings, but an image recording apparatus of popular model or entry model is not. Further, depending on preference of a user and irrespective of whether the model is high-end or entry, sometimes an image recording apparatus is equipped with further another sheet supply tray and/or is constructed such that a still higher-speed feeding mode is optionally settable. It is undesirable to enable these various settings by designing for each of the settings a transmission mechanism and a drive switching mechanism, and preparing components, such as a gear and a shaft, exclusively for each model, since it costs high. That is, to reduce the cost of an image recording apparatus, it is desirable to use as many components as possible commonly among various models.
In the image recording apparatus which can be optionally equipped with a sheet supply tray or cassette, and/or in which the high-speed or higher-speed feeding mode is settable, it is desired to transmit a driving torque from a motor to a pickup roller and a feeder roller by means of a simple arrangement, while reducing the cost of the components of the image recording apparatus as well as enhancing the efficiency of assembling of the image recording apparatus.
This invention has been developed in view of the above-described situations, and it is an object of the invention, therefore, to provide a sheet feeding apparatus which can economically transmit a driving torque from a driving source to a plurality of rollers, or simply enable optional settings, and an image recording apparatus including the sheet feeding apparatus.
To attain the above object, the invention provides a sheet feeding apparatus including: (a) a sheet holding portion which holds a sheet; (b) a feed path which guides the sheet supplied from the sheet holding portion; (c) a driving source which can rotate in two opposite directions; (d) a feeder roller which is disposed in the feed path and rotated by a driving torque of the driving source; (e) a pickup roller which can rotate in contact with the sheet held in the sheet holding portion; (f) a switchable transmission mechanism which is disposed between the pickup roller and the driving source, and is switchable at least between a first state for transmitting to the pickup roller a rotation of the driving source in a forward direction, and a second state for not transmitting a rotation of the driving source to the pickup roller, the forward direction in which the driving source is rotated in the first state being a direction opposite to a direction in which the driving source is rotated to rotate the feeder roller in a sheet feed direction which is a direction to feed the sheet; and (g) a control portion which (i) rotates the driving source in the forward direction to rotate the pickup roller in a sheet supply direction which is a direction to supply the sheet, and switches the switchable transmission mechanism to the first state, when the sheet is supplied from the sheet holding portion, and (ii) rotates the driving source in the direction opposite to the forward direction, and switches the switchable transmission mechanism to the second state, when the sheet is fed by the feeder roller.
The sheet held in the sheet holding portion is supplied into the feed path by the pickup roller, and then fed by the feeder roller. Each of the pickup roller and the feeder roller is rotated by a driving torque from the driving source. The driving torque of the driving source is transmitted to the pickup roller through the switchable transmission mechanism. When the control portion supplies the sheet from the sheet holding portion and then feeds the sheet along the feed path, the control portion (a) switches the switchable transmission mechanism to the first state, as well as rotates the driving source in a direction to rotate the pickup roller in the sheet supply direction to supply the sheet from the sheet holding portion (the direction in which the driving source is rotated when the sheet is supplied from the sheet holding portion is referred to as “forward direction” in this specification), and then (b) rotates the driving source in the direction opposite to the forward direction in order to feed the sheet by the feeder roller. The direction of rotation of the driving source opposite to the forward direction may be referred to as “reverse direction” in this specification. When the control portion switches the switchable transmission mechanism to the second state, a rotation of the driving source is not transmitted to the pickup roller.
It is noted that the forward and reverse directions with respect to rotation of the driving source are relatively defined, and thus either one of the two opposite rotation directions of the driving source may be referred to as forward direction as long as the other of the two opposite directions is referred to as reverse direction.
In a preferable form of the invention, while the switchable transmission mechanism is in the first state, the feeder roller and the pickup roller are rotated in respective directions that are opposite to each other, irrespective of whether the rotation direction of the driving source is forward or reverse. While the pickup roller is rotating in a direction to supply the sheet from the sheet holding portion on the basis of the forward rotation of the driving source, the feeder roller is rotating in order to deskew the sheet, namely, rotating in a direction opposite to a direction in which the feeder roller rotates while the feeder roller is feeding the sheet. While the feeder roller is rotating in the sheet feed direction on the basis of the reverse rotation of the driving source, the feeder roller is feeding the sheet along the feed path.
As described later, sometimes it does not cause any trouble to rotate, while the feeder roller rotates in the direction to feed the sheet, the pickup roller in a direction opposite to the direction in which the pickup roller rotates when supplying a sheet. However, it is desirable that the pickup roller is freely rotatable while the feeder roller rotates in the direction to feed the sheet. One advantage of enabling to establish the second state is to meet this demand, but there are further advantages thereof. For instance, it is possible to enable to transmit a rotation of the driving source to an operable device other than the pickup roller while the second state is established. One example of such a case is described below as one embodiment of the invention where a sheet supply cassette is optionally included and a rotation of the driving source is transmitted to another pickup roller that is disposed to supply a sheet from the sheet supply cassette.
The above and other objects, features, advantages and technical and industrial significance of the present invention will be better understood by reading the following detailed description of preferred embodiments of the invention, when considered in connection with the accompanying drawings, in which:
Hereinafter, there will be described one presently preferred embodiment of the invention, by referring to the accompanying drawings.
In
The printer portion 2 operates to record an image or a document, on a recording sheet. Data of the image or document recorded on the recording sheet 9 is transmitted from an external information apparatus, which may be a computer or a digital camera, for instance. It is also possible to read image data from a storage medium inserted in the multifunction apparatus 1, and record an image on a recording sheet based on the image data by operating the printer portion 2. As the storage medium, various kinds of memory cards can be used. Further, it is also possible to read image data by the scanner portion 3, and record an image on a recording sheet based on the thus read image data by operating the printer portion 2.
The printer portion 2 has a sheet feeding apparatus according to the invention. At a front side of the multifunction apparatus 1 and in the printer portion 2, an opening 10 is formed. Inside the opening 10, a sheet supply tray 20 and a sheet catch tray 21 are disposed in vertical relation to each other, namely, the sheet catch tray 21 is over the sheet supply tray 20. The sheet supply tray 20 is one form of a first sheet holding portion according to the invention. The sheet supply tray 20 holds a recoding sheet. More specifically, the sheet supply tray 20 can hold a plurality of recording sheets 9 (shown in FIGS. 2 and 24-28) that are stacked and in various sizes not larger than A4 size, for instance, recording sheets of B5 size or postcards. The sheet supply tray 20 has an extension tray 17, which can be pulled to the front side of the multifunction apparatus 1 in order to enlarge a sheet supporting area of the sheet supply tray 20. By the provision of such an extension tray 17, the sheet supply tray 20 can hold a recording sheet of legal size. The recording sheet 9 held in the sheet supply tray 20 is supplied or fed out into the inside of the printer portion 2. A desired image is recorded on the thus supplied recording sheet 9, and then the recording sheet 9 is ejected onto the sheet catch tray 21.
Under the sheet supply tray 20, there is disposed a sheet supply cassette 11. The sheet supply cassette 11 is one form of a second sheet holding portion according to the invention. The multifunction apparatus 1 has housings 12, 13 that are vertically arranged. The housing 13 has an opening at its front side into which the sheet supply cassette 11 is extractably insertable, but the front opening of the housing 13 is not shown in
The scanner portion 3 constituting an upper portion of the multifunction apparatus 1 includes a flatbed scanner and an auto document feeder 4 that is an automatic document feeding mechanism. Since the scanner portion 3 is not directly relevant to the invention, detailed description thereof is omitted.
At a front side of the upper portion of the multifunction apparatus 1, an operation panel 5 is disposed. In the operation panel 5, various kinds of manual operation buttons and a liquid crystal display are disposed. The manual operation buttons include, for instance, a power button operated to turn on and off the multifunction apparatus 1, a start button operated to input an instruction to start reading or recording an image, a stop button operated to input an instruction to stop an operation, a mode selector button operated to selectively establish one of a plurality of modes, such as copy mode, scanner mode, and facsimile mode, and a numeric keypad operated to make various kinds of settings such as conditions of image recording or image reading and to input a facsimile number. The multifunction apparatus 1 operates in accordance with instructions inputted through the operation panel 5. In the case where the multifunction apparatus 1 is connected with an external information apparatus, the multifunction apparatus 1 can operate in accordance with an instruction received from the external information apparatus through software such as a printer driver or a scanner driver.
At the front side of the multifunction apparatus 1, a slot portion 6 is disposed. Into the slot portion 6, a plurality of kinds of small memory cards are insertable. Data of a plurality of images stored in a small memory card inserted in the slot portion 6 is read out when a predetermined instruction is inputted through the operation panel 5. Information related to the data of the images thus read is presented on the liquid crystal display in the operation panel 5. Based on the presented information, a desired one of the images can be recorded by the printer portion 2 on the recording sheet 9.
There will be now described an internal structure of the multifunction apparatus 1.
The first feed path 23 extends from the first separator plate 22 initially upward and then frontward, and ends at the sheet catch tray 21. On the upstream side of the sheet catch tray 21 with respect to a direction in which the recording sheet 9 is fed (which direction will be hereinafter referred to as “feeding direction”), an image recording unit 24 is disposed. The recording sheet 9 supplied into the first feed path 23 from the sheet supply tray 20 is then guided upward from a lower side by and along the first feed path 23 to a position corresponding to the image recording unit 24, during which the recording sheet 9 is turned over. At the position corresponding to the image recording unit 24, the recording sheet 9 is subjected to image recording, that is, an image is recorded on the recording sheet 9 by the image recording unit 24. Then, the recording sheet 9 is ejected onto the sheet catch tray 21.
Over the sheet supply tray 20, a first pickup roller 25 is disposed. The first pickup roller 25 is supported at a distal end of a first swing arm 26 such that the first pickup roller 25 is rotatable. A pivot point of the first swing arm 26 is provided by a pivot shaft 30, that is, the first swing arm 26 is pivotable around the pivot shaft 30 and thus vertically movable such that the first pickup roller 25 can be brought into contact with, and separated away from, the sheet supply tray 20. The first swing arm 26 is held biased downward, that is, in a direction to contact the sheet supply tray 20, by its own weight or by a force from a spring or others. The first swing arm 26 retracts upward when the sheet supply tray 20 is inserted and pulled out. When the first swing arm 26 moves downward, the first pickup roller 25 at the distal end of the first swing arm 26 is brought into contact with the topmost one of the recording sheets 9 on the sheet supply tray 20.
The first pickup roller 25 receives a driving torque from a LF motor 107 (Line Feed Motor) shown in
The first feed path 23 is defined between an outer guide surface and an inner guide surface that are opposed to each other with a spacing therebetween, except a part where the image recording unit 24 is disposed. For instance, a portion of the first feed path 23 at the rear side of the multifunction apparatus 1 where the first feed path 23 is curved is defined between first and second guide members 18, 19 that are opposed to each other with a spacing therebetween and are fixed to a frame of the multifunction apparatus 1. Although not shown in
On the downstream side, in the feeding direction, of the curved portion of the first feed path 23, the image recording unit 24 is disposed. The image recording unit 24 includes a carriage 38 and a recording head 39 mounted on the carriage 38. The carriage 38 reciprocates in a main scanning direction, which is a direction intersecting the feeding direction. In this specific example, the main scanning direction is perpendicular to the feeding direction. To the recording head 39, cyan (C), magenta (M), yellow (Y), and black (Bk) inks are supplied from respective ink cartridges via ink tubes 41 shown in
The guide rail 43 is one of the two guide rails 43, 44 that is disposed on the upperstream side than the other guide rail 44 with respect to the feeding direction. The guide rail 43 is an elongate plate member, a length or a dimension of which in the lateral direction of the first feed path 23 (i.e., the lateral direction as seen in
On an upper surface of the guide rail 44, a belt drive mechanism 46 is disposed. The belt drive mechanism 46 includes a drive pulley 47, a driven pulley 48, and a timing belt 49. The drive pulley 47 and the driven pulley 48 are respectively disposed at two longitudinal end portions of the guide rail 44 to be rotatable around respective rotation shafts extending in a vertical direction of the multifunction apparatus 1, which is perpendicular to a surface of the sheet on which
The carriage 38 is coupled at its bottom side to the timing belt 49. The circulation of the timing belt 49 reciprocates the carriage 38 in sliding contact with the guide rails 43, 44. The recording head 39 reciprocates with the carriage 38 in the lateral direction of the first feed path 23 that corresponds to the main scanning direction.
On the guide rail 44, an encoder strip 50 of a linear encoder 113 (shown in
On the encoder strip 50 is put a pattern such that a light-blocking portion where light can not pass through and a light-transmissive portion where light is allowed to pass through are alternately arranged at a constant pitch along the longitudinal direction of the encoder strip 50. On an upper surface of the carriage 38 and at a position corresponding to the encoder strip 50, an optical sensor 35 is disposed. The optical sensor 35 is a light-transmission sensor that has a light emitting element and a light receiving element. The optical sensor 35 reciprocates with the carriage 38 along the longitudinal direction of the encoder strip 50. During this reciprocation, the optical sensor 35 detects the pattern of the encoder strip 50. Although not shown in
As
As
The purge mechanism 51 sucks and removes bubbles and foreign matter from nozzles formed in the recording head 39. As
The nozzle cap 52 is formed of rubber and can establish a sealing engagement with the nozzle surface of the recording head 39 around the nozzles. A space inside the nozzle cap 52 is divided into two smaller spaces, one of which corresponds to nozzles for the color (CMY) inks, and the other of which corresponds to nozzles for the black (Bk) ink. At positions on an inner surface of the nozzle cap 52 corresponding to the two smaller spaces, respectively, support members 57, 58 are fitted. The support members 57, 58 function to prevent buckling or inclination of a lip portion of the nozzle cap 52. Although not shown in
The air-outlet cap 53 is formed of rubber and can establish a sealing engagement with the nozzle surface of the recording head 39 around the air outlets. Inside the air-outlet cap 53, four push rods 60 extend vertically upward to correspond to the respective air outlets for the C, M, Y, and Bk inks. When each push rod 60 is inserted into the corresponding air outlet, a check valve of the air outlet opens. The push rods 60 are disposed to be able to upward advance out of the air-outlet cap 53. For instance, among the four push rods 60, three of them 60 for the color (C, M, and Y) inks are together advanced upward out of the air-outlet cap 53, and the other push rod 60 for the black (Bk) ink is advanced upward out of the air-outlet cap 53 independently of the other three push rods 60. When the three push rods 60 for the CMY inks or the push rod 60 for the Bk ink, or all of the push rods 60, are upward advanced out of the air-outlet cap 53, the push rod(s) 60 are/is inserted into the corresponding air outlet(s) formed in the recording head 39. At a bottom of the air-outlet cap 53, there opens an air inlet 61, which is connectable to the pump 54 via the port switching mechanism 59.
The port switching mechanism 59 selectively makes a switch between (a) a state where a suction passage in communication with the air inlets of the nozzle cap 52 is connected to the pump 54, and a suction passage in communication with the air inlet 61 of the air-outlet cap 53 is disconnected from the pump 54, and (b) a state where the suction passage in communication with the air inlets of the nozzle cap 52 is disconnected from the pump 54, and the suction passage in communication with the air inlet 61 of the air-outlet cap 53 is connected to the pump 54.
The pump 54 is of so-called rotary type and has a pump gear that is rotated when the pump 54 is operated to suck bubbles and foreign matter. To the pump gear, a driving torque is transmitted via a bevel gear 62. In
The lifting mechanism 55 translates a holder 63 between a standby position and a contact position by a pair of isometric links 64 disposed at the right-hand side and the left-hand side, respectively.
The wiper blade 56 is disposed on a wiper holder 68 such that the wiper blade 56 can protrude from and retract into the wiper holder 68. The wiper blade 56 is formed of rubber and has a length corresponding to that of the nozzle surface of the recording head 39. When the wiper blade 56 is made to protrude from the wiper holder 68, a tip or an upper end of the wiper blade 56 contacts the nozzle surface of the recording head 39 across the entire length thereof in the feeding direction. As the recording head 39 is laterally moved with the carriage 38 with the wiper blade 56 in contact with the nozzle surface of the recording head 39, the wiper blade 56 wipes off inks adhering to the nozzle surface. The wiper blade 56 is protruded and retracted by a cam mechanism not shown. The cam mechanism makes the wiper blade 56 protrude when the recording head 39 is to be slid toward the image recording range after purging has been implemented.
When bubbles and others are to be removed from the recording head 39 by sucking them, the recording head 39 is moved in order that the carriage 38 is located over the nozzle cap 52 and the air-outlet cap 53, whereby the contact lever 65 is pushed by the carriage 38 and thus the nozzle cap 52 and the air-outlet cap 53 are moved to the contact position by the operation of the lifting mechanism 55 and brought into contact with the recording head 39. Thus, a sealing engagement is established between the nozzle cap 52 and the recording head 39 around the nozzles, and between the air-outlet cap 53 and the recording head 39 around the air outlets. The port switching mechanism 59 switches the connecting/disconnecting state of the nozzle cap 52 and the air-outlet cap 53 with/from the pump 54 in a predetermined manner. For instance, when the inks are to be sucked from the nozzles of the recording head 39, the nozzle cap 52 is connected to the pump 54 and the air-outlet cap 53 is disconnected from the pump 54. In this state, a driving torque is transmitted from the LF motor 107 to the bevel gear 62 of the pump 54, whereby the pump 54 performs a sucking operation. By the sucking operation of the pump 54, a negative pressure is produced inside the nozzle cap 52, thereby sucking the inks from the nozzles of the recording head 39. The bubbles and foreign matter in the nozzles are sucked together with the inks and removed thereby. Thereafter, as the carriage 38 is moved off from the contact lever 65, the nozzle cap 52 and the air-outlet cap 53 are moved to the standby position by the operation of the lifting mechanism 55. Further, the wiper blade 56 is brought into contact with the nozzle surface of the recording head 39 that is being slid with the carriage 38 on which the recording head 39 is mounted, in order to wipe off the inks adhering to the nozzle surface of the recording head 39.
As
On the downstream side of the image recording unit 24, a pair of rollers, namely, an ejection roller 80 and a gear roller 81, are disposed. The ejection roller 80 and the gear roller 81 nip therebetween the recording sheet 9 on which an image has been recorded, and feed the recording sheet 9 to the sheet catch tray 21. The feeder roller 78 and the ejection roller 80 are intermittently driven at the constant pitch corresponding to the line feed width, by a driving torque from the LF motor 107. The rotations of the feeder roller 78 and the ejection roller 80 are synchronized. The feeder roller 78 is provided with a rotary encoder 112 (shown in
Since the gear roller 81 contacts the recording sheet 9 on which an image has been recorded, teeth like those of a spur are formed on a circumferential surface of the gear roller 81 so as not to degrade the image recorded on the recording sheet 9 by the contact of the gear roller 81 with the recording sheet 9. The gear roller 81 is movable toward and away from the ejection roller 80, and held biased by a coil spring in a direction to contact the ejection roller 80. When a recording sheet 9 is fed into the nip between the ejection roller 80 and the gear roller 81, the gear roller 81 presses the recording sheet 9 onto the ejection roller 80 while retracting by an amount corresponding to a thickness of the recording sheet 9 against the biasing force of the coil spring. Hence, the recording sheet 9 can be fed with stability.
As
From the second separator plate 82, a second feed path 83 extends upward. The second feed path 83 then turns to the front side of the multifunction apparatus 1, and is connected with the first feed path 23 at a position upstream of the feeder roller 78 with respect to the feeding direction. The second feed path 83 is defined between the second guide member 19 and a third guide member 28 disposed on the outer or rear side of the second guide member 19. That is, an inner guide surface of the second feed path 83 is provided by a rear surface of the second guide member 19, a front surface of which provides the outer guide surface of the first feed path 23. Each of the recording sheets 9 accommodated in the sheet supply cassette 11 is guided upward in a U-turn manner by and along the second feed path 83 into the first feed path 23. Then, an image is recorded on the recording sheet 9 by the image recording unit 24, after which the recording sheet 9 is ejected onto the sheet catch tray 21.
In the first feed path 23, a registration sensor 27 is disposed, at a position between a point where the first and second feed paths 23, 83 join and a point where the feeder roller 78 and the pinch roller 79 are disposed. Although details are not shown in
Over the sheet supply cassette 11, a second pickup roller 89 is disposed to supply recording sheets 9 stacked on the sheet supply cassette 11 into the second feed path 83. A rotation shaft of the second pickup roller 89 is supported at a distal end of a second swing arm 90. To the second pickup roller 89, a driving torque of the LF motor 107 (shown in
The second swing arm 90 is pivotable around a pivot shaft 95 to be vertically movable toward and away from an inner bottom surface of the sheet supply cassette 11. The second swing arm 90 is held biased by its own weight or a biasing force of a spring or others in a direction to contact the sheet supply cassette 11. The second swing arm 90 retracts upward when the sheet supply cassette 11 is inserted and pulled out. When the second swing arm 90 moves downward, the second pickup roller 89 at the distal end of the second swing arm 90 is brought into contact with the stack of recording sheets 9 accommodated in the sheet supply cassette 11. When the second pickup roller 89 is rotated in this state, a topmost one of the stacked recording sheets 9 is supplied or fed out toward the second separator plate 82 by friction between a circumferential surface of the second pickup roller 89 and the topmost recording sheet. The recording sheet 9 fed out comes to contact at its leading edge with the second separator plate 82 and is thereby guided upward into the second feed path 83. At this time, multi-feeding sometimes occurs, that is, when the topmost recording sheet 9 is fed out by the second pickup roller 89, the next recording sheet 9 immediately under the topmost recording sheet 9 may be together fed out due to friction or an electrostatic force. However, the next recording sheet 9 inhibited from further proceed by its contact with the second separator plate 82.
The ROM 102 stores programs for controlling various operations of the multifunction apparatus 1, and others. The RAM 103 is used as a storage area or a work area for temporarily storing various kinds of data that are used when the CPU 101 executes the programs. The EEPROM 104 stores settings, flags, and others that should be held even after the multifunction apparatus is turned off.
In the printer portion 2, each recording sheet 9 supplied from the sheet supply tray 20 is fed in a selected one of two feeding modes, namely, a normal feeding mode and a high-speed feeding mode. That is, when the printer portion 2 is in the normal feeding mode, recording sheets 9 are one by one supplied from the sheet supply tray 20 into the first feed path 23 and then each recording sheet is subjected to deskewing by the feeder roller 78 and the pinch roller 79. Thereafter, the recording sheet 9 is fed to a position over the platen 42 where image recording is performed, after which the image recording sheet 9 is ejected onto the sheet catch tray 21. Then, the next recording sheet 9 is supplied from the sheet supply tray 20, and the same processing is repeated for the next recording sheet 9. When the printer portion 2 is in the high-speed feeding mode, recording sheets 9 are consecutively supplied from the sheet supply tray 20 into the first feed path 23. That is, as soon as a first recording sheet 9 has been supplied from the sheet supply tray 20, the next recording sheet 9 is supplied from the sheet supply tray 20. Since a speed of rotation of the feeder roller 78 is set higher than that of the first pickup roller 25, the first recording sheet nipped between the feeder roller 78 and the pinch roller 79 is fed in the first feed path 23 at a speed higher than a speed at which the next recording sheet 9 is fed, thereby producing a predetermined distance between the first and next recording sheets 9. It is noted that in the high-speed feeding mode, the feeder roller 78 and the pinch roller 79 do not operate to deskew the recording sheets. Images are consecutively recorded on the recording sheets 9 that are sequentially fed with each two recording sheets 9 consecutively fed being separated from each other by the predetermined distance.
Programs for controlling operations of the LF motor 107 and other members in the normal and high-speed feeding modes are respectively stored in the ROM 102. A program for controlling feeding of recording sheets 9 from the sheet supply cassette 11 and a program for controlling a purging operation are also stored in the ROM 102. When image recording is to be performed, the user sets recording conditions that are held in the RAM 103 for a predetermined time period. Thereafter when an instruction to start the image recording is inputted, the CPU 101 operates the printer portion 2 to perform the image recording, that is, controls the operations of the LF motor 107 and other members on the basis of the recording conditions held in the RAM 103. The recording conditions include: which one of the sheet supply tray 20 and the sheet supply cassette 11 is selected as the sheet holding portion from which recording sheets 9 are to be supplied; which one of the normal feeding mode and the high-speed feeding mode is selected as the feeding mode in which the recording sheets 9 are to be fed; and a resolution at which images are to be recorded.
The ASIC 106 generates, for instance, a phase excitation signal for energizing the LF motor 107 in accordance with an instruction from the CPU 101, and outputs the signal to a drive circuit 108 of the LF motor 107 to control rotation of the LF motor 107. The LF motor 107 is rotatable in two opposite directions, namely, in a forward direction and a reverse direction.
The drive circuit 108 is for driving the LF motor 107, by receiving the signal outputted from the ASIC 106, and generating an electrical signal based on which the LF motor 107 is rotated. The LF motor 107 receives the electrical signal and accordingly rotates. The torque of the LF motor 107 is transmitted to the first pickup roller 25, the purge mechanism 51, the feeder roller 78, the ejection roller 80, and the second pickup roller 89, via a drive switching mechanism and transmission assemblies. The drive switching mechanism and transmission assemblies will be described later.
The ASIC 106 generates a phase excitation signal for energizing the CR motor 109 in accordance with an instruction from the CPU 101, and outputs the signal to a drive circuit 110 of the CR motor 109, thereby controlling rotation of the CR motor 109.
The drive circuit 110 is for driving the CR motor 109. The drive circuit 110 receives the signal outputted from the ASIC 106 and generates an electrical signal based on which the CR motor 109 is rotated. The CR motor 109 receives the electrical signal and accordingly rotates. The torque of the CR motor 109 is transmitted to the carriage 38 via the belt drive mechanism 46, thereby reciprocating the carriage 38. In this way, reciprocation of the carriage 38 is controlled by the control portion 100.
A drive circuit 111 is for selectively ejecting droplets of the four inks of respective colors from the recording head 39 onto a recording sheet at predetermined timings. More specifically, the ASIC 106 generates a signal on the basis of a drive control procedure outputted from the CPU 101, and outputs the signal to the drive circuit 111 which accordingly controls an operation of the recording head 39. The drive circuit 111 is mounted on the head control board. The signal is transmitted from the mainboard constituting the control portion 100 to the head control board, through the flat cable 85.
To the ASIC 106 are connected the registration sensor 27 that detects a recording sheet 9 in the first feed path 23, the rotary encoder 112 that detects an amount of rotation of the feeder roller 78, and the linear encoder 113 that detects the position of the carriage 38. When the multifunction apparatus 1 is turned on, the carriage 38 is moved to one of two longitudinal ends of the guide rails 43, 44, and the position of the carriage 38 as detected by the linear encoder 113 and stored is initialized or reset to an initial position. When the carriage 38 moves in sliding contact with the guide rails 43, 44 from the initial position, the optical sensor 35 disposed in the carriage 38 detects the pattern of the encoder strip 50, and the control portion 100 counts pulse signals corresponding to the detected pattern. The count of the pulse signals represents an amount of movement of the carriage 38. Based on the amount of movement of the carriage 38, the control portion 100 controls the operation of the CR motor 109 so as to control the reciprocation of the carriage 38.
To the ASIC 106 are also connected the scanner portion 3, the operation panel 5 through which instructions related to operations of the multifunction apparatus 1 are inputted, the slot portion 6 in which various kinds of small memory cards are inserted, and a parallel interface 114 and a USB interface 115 for enabling data communication with an external information apparatus such as personal computer via a parallel cable and a USB cable, respectively, and others. Further, a NCU (Network Control Unit) 116 and a modem 117 are connected to the ASIC 106 in order to enable the facsimile function.
There will be now described the drive switching mechanism for switching an object to which a driving torque of the LF motor 107 is transmitted, among the first pickup roller 25, the purge mechanism 51, and the second pickup roller 89. A state where a driving torque of the LF motor 107 is transmittable to the first pickup roller 25 corresponds to a first state according to the invention, and a state where a driving torque of the LF motor 107 is transmittable to the second pickup roller 89 corresponds to a second state according to the invention. In the second state, a driving torque of the LF motor 107 is not transmitted to the first pickup roller 25.
On the rear side of the drive gear 120, a switch gear 121 is disposed. The switch gear 121 is one form of a third gear according to the invention. The switch gear 121 is normally in engagement with the drive gear 120. An axis of the switch gear 121 is parallel with that of the drive gear 120, and the switch gear 121 can be translated relative to the drive gear 120. A length of the drive gear 120 in a direction of its axis corresponds to a range of translation of the switch gear 121, and the drive gear 120 and the switch gear 121 are held engaged with each other across the entire range of translation of the switch gear 121.
Obliquely under the drive gear 120, the first to fourth transmission gears 123-126 arranged in a row are mounted on the shaft 122 that extends parallel to the axis of the drive gear 120. The shaft 122 is disposed in the purge mechanism 51, as shown in
The transmission gears 123-126 transmit a driving force to respective driven portions. More specifically, the first transmission gear 123 and the second transmission gear 124 transmit a driving torque of the LF motor 107 to the first pickup roller 25 in the normal feeding mode and in the high-speed feeding mode, respectively. The third transmission gear 125 transmits a driving torque of the LF motor 107 to the second pickup roller 89. The fourth transmission gear 126 transmits a driving torque of the LF motor 107 to the purge mechanism 51. The transmission gears 123-126 have a same diameter, and the switch gear 121 is selectively meshed with one of the transmission gears 123-126. That is, the switch gear 121 is engageable with and disengageable from the transmission gears 123-126. The first transmission gear 123 is one form of a second gear according to the invention. The third transmission gear 125 is one form of the fourth gear according to the invention. The state where the switch gear 121 is in meshing engagement with the first transmission gear 123 corresponds to the first state according to the invention. The state where the switch gear 121 is in meshing engagement with the third transmission gear 125 corresponds to the second state according to the invention.
As
As
As
As
The transmission gear 175 is mounted on a rotation shaft 176 of the first pickup roller 25 such that the transmission gear 175 is rotatable relative to the rotation shaft 176. From the rotation shaft 176, keys 177 protrude radially outward. On an inner circumferential surface of the transmission gear 175, recesses 178 are formed to positionally correspond to the keys 177. A length or a dimension of each of the recesses 178 in a circumferential direction of the transmission gear 175 is sufficiently large with respect to that of each of the keys 177. That is, the keys 177 are fitted in the respective recesses 178 with a play in the circumferential direction. When the transmission gear 175 rotates, each key 177 comes to contact with a wall at a circumferential end of the corresponding recess 178, and thus a rotation of the transmission gear 175 is transmitted to the rotation shaft 176. Thus, when the transmission gear 175 rotates, the first pickup roller 25 also rotates. A direction in which the first pickup roller 25 rotates is opposite, with respect to the feeding direction, to a direction in which the feeder roller 78 rotates. That is, when the first pickup roller 25 rotates in a sheet supply direction (counterclockwise as seen in
As
The transmission gear 188 is mounted on a rotation shaft 189 of the second pickup roller 89 such that the transmission gear 188 is rotatable relative to the rotation shaft 189. From the rotation shaft 189, keys 190 protrude radially outward. On an inner circumferential surface of the transmission gear 188, recesses 191 are formed to positionally correspond to the keys 190. A length or a dimension of each of the recesses 191 in a circumferential direction of the transmission gear 188 is sufficiently large with respect to that of each of the keys 190. That is, the keys 190 are fitted in the respective recesses 191 with a play in the circumferential direction. When the transmission gear 188 rotates, each key 190 comes to contact with a wall at a circumferential end of the corresponding recess 191, and thus a rotation of the transmission gear 188 is transmitted to the rotation shaft 189. Hence, when the transmission gear 188 rotates, the second pickup roller 89 also rotates. A direction in which the second pickup roller 89 rotates is opposite, with respect to the feeding direction, to a direction in which the feeder roller 78 rotates. That is, when the second pickup roller 89 rotates in the sheet supply direction (counterclockwise as seen in
There will be described the drive switching mechanism in more detail. The drive switching mechanism is mainly composed of the switch gear 121, the first to fourth transmission gears 123-126, an input lever 138, a biasing member 139, and a lever guide 150.
As shown in
As
The biasing member 139 includes a boss portion 143 and a slide guide 144. The boss portion 143 is a hollow cylindrical portion, and fitted on the hollow cylinder portion 140 of the input lever 138. The slide guide 144 protrudes radially outward from the boss portion 143 in a Y-like shape, that is, the slide guide 144 includes two arm portions at its upper side. As shown in
By receiving the biasing forces in the directions of the arrows 147, 148, the switch gear 121, the input lever 138, and the biasing member 139 are together movable in contact with one another, on the support shaft 137. The biasing force exerted on the biasing member 139 in the direction of the arrow 147 by the compression coil spring 147a is set to be larger than the biasing force exerted on the switch gear 121 in the direction of the arrow 148 by the compression coil spring 148a. Hence, while receiving no external forces, the switch gear 121, the input lever 138, and the biasing member 139 are held at a leftmost position as seen in
As shown in
First to fourth guide positions 152-155 are set or defined along the edge of the guide hole 151 such that the guide positions 152-155 are arranged along the axial direction of the support shaft 137 and in an ascending order of the reference numerals in the direction of the arrow 148. The second guide position 153 is defined by a cutout, or a portion of the guide hole 151 where the guide hole 151 is enlarged in a direction indicated by an arrow 149 as compared with the first guide position 152. Similarly, the third guide position 154 is defined by another cutout or another portion of the guide hole 151 where the guide hole 151 is enlarged in the direction of the arrow 149 as compared to the first guide position 152. That is, the second and third guide positions 153, 154 are defined on opposite sides of a protrusion as a part of the lever guide 150. This protrusion provides a slant surface for guiding and smoothing a movement of the arm 141 from the second guide position 153 to the third guide position 154. When located at either of the second and third guide positions 153, 154, the arm 141 of the input lever 138 is engaged with the cutout or enlarged portion of the guide hole 151, and thereby inhibited from further being rotated in the direction of the arrow 149 due to the rotation torque produced by the slant guide surface 145 the compression coil spring 147a and further being moved in the direction of the arrow 147 due to the difference between the biasing forces of the compression coil springs 147a, 148a. As shown in
The fourth guide position 155 is spaced from the third guide position 154 in the direction of the arrow 148 much more widely than between the guide positions 152 and 153, and between the guide positions 153 and 154. The fourth guide position 155 is formed at an end of the guide hole 151 in the axial direction of the support shaft 137 on the side opposite to the first guide position 152. At the fourth guide position 155, the guide hole 150 is narrowed in a direction opposite to the direction of the arrow 149, such that a slant surface is provided between the third and fourth guide positions 154, 155. Guided by this slant surface, the arm 141 is smoothly movable from the third guide position 154 to the fourth guide position 155. When located at the fourth guide position 155, the arm 141 is not engaged with respect to the direction of the arrow 147, that is, not inhibited from moving due to the biasing force that is exerted on the input lever 138 in the direction of the arrow 147 based on the elastic force of the compression coil spring 147a. Hence, in order to hold the arm 141 at the fourth guide position 155, a guide plate 92 (described later) is used. As shown in
At another edge 158 of the guide hole 151 that is opposed to the second and third guide positions 153, 154, a return guide 157 is formed. The return guide 157 has a hook-like shape that includes a first vertical portion extending vertically upward from the edge 158 of the guide hole 151, a horizontal portion that extends horizontally from an upper end of the first vertical portion to a position corresponding to a middle portion of the guide hole 151, and a second vertical portion that extends vertically downward from an end of the horizontal portion on the side opposite to the upper end of the first vertical portion, to a vertical position lower than an upper end of the arm 141. The return guide 157 guides the arm 141 returning from the fourth guide position 155 to the first guide position 152 in order to prevent the arm 141 from engaging with the cutouts of the second and third guide positions 153, 154. A width of the return guide 157 corresponds to a range between the second guide position 153 and a position slightly to the left (as seen in
As shown in
The oblique surface 93 is brought into contact with the arm 141 when the arm 141 is located at one of the first to third guide positions 152-154. The oblique surface 93 is inclined in a direction to push the arm 141 to the side of the first to third guide positions 152-154, that is, in a direction to further rotate or turn the input lever 138 as rotated in the direction of the arrow 149 by being guided by and along the guide surface 145 of the biasing member 139. Hence, when the guide plate 92 is moved with the carriage 38 in the direction indicated by an arrow 159 (shown in
As
There will be described an operation of the printer portion 2. The printer portion 2 records an image on a recording sheet 9 that is fed in a selected one of the following three ways: (i) fed from the sheet supply tray 20 and in the normal feeding mode, (ii) fed from the sheet supply tray 20 and in the high-speed feeding mode, and (iii) fed from the sheet supply cassette 11 and in the normal feeding mode. In addition, the printer portion 20 performs a maintenance operation for the recording head 39. Among these, the image recording with a recording sheet 9 fed from the sheet supply tray 20 and in the normal feeding mode will be described first.
Upon receiving the instruction, the control portion 100 starts executing the control routine, which begins with step S1, in which the control portion 100 operates the CR motor 109 to move the carriage 38 in order to locate the arm 141 of the input lever 138 at the first guide position 152, as shown in
As
When an affirmative decision (YES) is made in step S3, that is, when the control portion 100 determines that the registration sensor 27 detects the leading edge of the recording sheet 9 and outputs an ON signal, the control flow goes to step S6 in which the control portion 100 rotates the LF motor 107 in the forward direction by a predetermined amount, and then to step S7 in which the control portion 100 stops the LF motor 107. After passing by the registration sensor 27, the leading edge of the recording sheet 9 comes to contact the feeder roller 78 and the pinch roller 79, as shown in
After the LF motor 107 is stopped in step S7, the control routine goes to step S8 in which the control portion 100 rotates the LF motor 107 in the reverse direction by a predetermined amount, in order that the reverse rotation of the LF motor 107 is transmitted to the feeder roller 78 and the pinch roller 79 that accordingly rotate in the sheet feed direction, i.e., a direction indicated by an arrow 163, as shown in
After the stop of the reverse rotation of the LF motor 107 in step S10, the control flow goes to step S11 in which the control portion 100 operates the CR motor 109 in order to move the carriage 38 to locate the arm 141 of the input lever 138 at the third guide position 154, as shown in
Then, the control flow goes to step S12 in which the control portion 100 implements an adjusting operation. The adjusting operation is implemented to stably move the switch gear 121 to one of four positions to engage with one of the first to fourth transmission gears 123-126. For instance, as described above, when the arm 141 of the input lever 138 is moved from the first guide position 152 to the third guide position 154, the switch gear 121 is biased by the compression coil spring 148a in the direction of the arrow 148 as seen in
As
The above-described operation of the printer portion 2 is implemented in a case where it is desired that the first pickup roller 25 is rotated by the recording sheet 9 that is being fed in contact with the first pickup roller 25 during the recording processing. However, depending on the conditions such as the material of the recording sheet 9, there is a case where such a demand does not exist. In the latter case, the embodiment may be modified such that in response to an instruction inputted through the operation panel 5, the control portion 100 skips switching of the drive switching mechanism to the second state and the adjusting operation. That is, after stopping the LF motor 107 in step S10, the control portion 100 skips steps S11 and S12 and directly proceeds to step S13 for implementing the recording processing. When the recording processing is started in this way, the recording sheet 9 is fed by the feeder roller 78 and the pinch roller 79 in the feeding direction, while the first pickup roller 25 is rotated in the direction opposite to the sheet feed direction. Hence, due to frictional resistance between the recording sheet 9 and the first pickup roller 25, a torque to upward move the first swing arm 26 occurs, whereby the first swing arm 26 jumps up to get off of the recording sheet 9 and then falls to contact the recording sheet 9, and this vertical movement (or jumping and falling) is repeated thereafter. As long as this vertical movement of the swing arm 26 substantially does not adversely affect the image recording on the recording sheet 9, the recording processing is preferably implemented in this modified manner since according to this modification the switching to the second state and the adjusting operation are omitted and the efficiency of recording is thus improved.
When an affirmative decision is made in step S14, that is, when it is determined that recording of one page is complete, the control flow goes to step S15 in which the control portion 100 reversely and consecutively rotates the LF motor 107 in order to eject the recording sheet 9 onto the sheet catch tray 21, as shown in
Then, the control flow goes to step S16 in which the control portion 100 determines whether recording of all the pages is complete. When a negative decision (NO) is made in step S16, that is, when it is determined that recording of all the pages is not complete, the control flow returns to step S1, namely, the control portion 100 operates the CR motor 109 to move the carriage 38 in order to locate the arm 141 of the input lever 138 at the first guide position 152, as shown in
On the other hand, when an affirmative decision (YES) is made in step S16, that is, when it is determined that recording of all the pages is complete, the control flow goes to step S17 in which the control portion 100 operates the CR motor 109 to move the carriage 38 in order to locate the arm 141 of the input lever 138 at the fourth guide position 155, as shown in
There will be now described the image recording with a recording sheet 9 fed from the sheet supply tray 20 and in the high-speed feeding mode. Upon receiving an instruction to perform image recording in the high-speed feeding mode, the control portion 100 operates the CR motor 109 to move the carriage 38 in order to locate the arm 141 of the input lever 138 at the second guide position 153, as shown in
When the switch gear 121 is in meshing engagement with the second transmission gear 124, a rotation of the drive gear 120 in synchronization with a rotation of the feeder roller in the sheet feed direction is transmitted to the first pickup roller 25 as a rotation thereof in the sheet supply direction. Hence, the topmost recording sheet 9 in the sheet supply tray 20 is supplied into the first feed path 23. A leading edge of the thus supplied recording sheet 9 is detected by the registration sensor 27, and then reaches the feeder roller 78 and the pinch roller 79. Since at this time the feeder roller 78 and the pinch roller 79 are rotating in the sheet feed direction, the leading edge of the recording sheet 9 is immediately nipped between the feeder roller 78 and the pinch roller 79 and fed to the position over the platen 42. That is, the recording sheet 9 is not deskewed.
A rotation speed of the feeder roller 78 is higher than that of the first pickup roller 25. Hence, the recording sheet 9 is fed by a combination of the feeder roller 78 and the pinch roller 79 at a speed higher than the rotation speed of the first pickup roller 25. A nip force with which the feeder roller 78 and the pinch roller 79 nips the recording sheet 9 therebetween is sufficiently larger than a contact force between the first pickup roller 25 and the recording sheet 9. Hence, a force rotating the first pickup roller 25 in the sheet supply direction is overcome by a forward force from the recording sheet 9 as being fed by the combination of the feeder roller 78 and the pinch roller 79, and the first swing arm 26 vertically moves, or alternately jumps up and falls. When a rear edge of the recording sheet 9 has passed a position of contact with the first pickup roller 25, the next recording sheet contacts the first pickup roller 25, whereby the next recording sheet is supplied from the sheet supply tray 20 into the first feed path 23. Since the rotation speed of the feeder roller 78 is higher than that of the first pickup roller 25, as described above, the rear edge of the recording sheet 9 and a leading edge of the next recording sheet are gradually separated from each other by a distance corresponding to a difference of the rotation speeds of the feeder roller 78 and the first pickup roller 25. Thus, it is prevented that two recording sheets are together fed one on another.
When the recording sheet 9 has been fed by the feeder roller 78 and the pinch roller 79 to the position over the platen 42 from which recording is initiated, the same recording processing as described above with respect to the image recording in the normal feeding mode is performed. Since when recording of a first page is complete, the next recording sheet for a second page is already supplied, the control portion 100 can immediately start recording the second page. Hence, in the high-speed feeding mode, the printer portion 2 performs image recording at a higher speed than in the normal feeding mode.
There will be next described the image recording with a recording sheet 9 fed from the sheet supply cassette 11 and in the normal feeding mode. Upon receiving an instruction to perform image recording with a recording sheet fed from the sheet supply cassette 11, the control portion 100 operates the CR motor 109 to move the carriage 38 in order to locate the arm 141 of the input lever 138 at the third guide position 154, as shown in
The recording sheet 9 supplied into the second feed path 83 then proceeds into the first feed path 23 in which the recording sheet 9 is detected by the registration sensor 27. Then, a leading edge of the recording sheet 9 comes to contact the feeder roller 78 and the pinch roller 79. The recording sheet 9 is deskewed in the same way as described above with respect to the case where image recording is performed with a recording sheet fed from the sheet supply tray 20 in the normal feeding mode. Thereafter, the control portion 100 reversely rotates the LF motor 107. The reverse rotation of the LF motor 107 rotates the feeder roller 78 and the pinch roller 79 in the sheet feed direction. The reverse rotation of the LF motor 107 transmitted to the feeder roller 78 is further transmitted sequentially to the drive gear 120, the switch gear 121, the third transmission gear 125, and the second transmission assembly 180. However, at the second transmission assembly 180, the transmission of the driving torque is disconnected by a movement of the planetary gear 182, and not transmitted to the second pickup roller 89. Hence, the second pickup roller 89 is rotated in the sheet supply direction by the recording sheet 9 being fed. When the recording sheet 9 has been fed, by the combination of the feeder roller 78 and the pinch roller 79, to the position over the platen 42 from which recording is initiated, the same recording processing as described above with respect to the case of the image recording with a recording sheet fed from the sheet supply tray 20 and in the normal feeding mode.
In the maintenance operation, the control portion 100 operates the CR motor 109 to move the carriage 38 in order to locate the arm 141 of the input lever 138 at the fourth guide position 155, as shown in
According to the present embodiment, the printer portion 2 of the multifunction apparatus 1 includes the sheet supply tray 20 and the sheet supply cassette 11, and a recording sheet is supplied selectively from one of the sheet supply tray 20 and the sheet supply cassette 11 by use of the drive switching mechanism including the four transmission gears 123-126. However, the sheet supply cassette 11, the second pickup roller 89, the second swing arm 90, and the second transmission assembly 180 are not essential for the multifunction apparatus 1, but the multifunction apparatus 1 may be such that these 11, 89, 90, 180 are optionally settable therein.
The structure of the transmission gears 123-126 of the drive switching mechanism may be modified in accordance with the option settings or the model of the multifunction apparatus 1. For instance, in the multifunction apparatus 1, the high-speed feeding mode in which the first pickup roller 25 is used, and the sheet supply cassette 11, are optionally includable, depending on the option settings and model. In other words, feeding from the sheet supply tray 20 in the normal feeding mode, and the purge mechanism 51, are normally and commonly included in all the models. That is, the first and third transmission gears 123, 125 are essential for the multifunction apparatus 1, but the second transmission gear 124 for transmitting a driving torque to the first pickup roller 25 in the image recording with a recording sheet fed from the sheet supply tray 20 in the high-speed feeding mode, and the third transmission gear 125 for transmitting a driving torque to the second pickup roller 89 in the recording with a recording sheet fed from the sheet supply cassette 11, are included if desired, depending on the option settings and other conditions. In a case where a driving torque is transmitted to the purge mechanism 51 along another transmission path that is not described above, the fourth transmission gear 126 may be omitted.
As shown in
As shown in
It is noted that even in the modification of the embodiment where the third transmission gear 125 is not disposed, engaging the switch gear 121 with the first transmission gear 123 establishes the first state where a rotation of a LF motor 107 is transmitted to a first pickup roller 25, and a rotation of the LF motor 107 is not transmitted to the first pickup roller 25 in a second state identical with that in the above-described embodiment. However, in the second state of the above-described embodiment, a driving torque is transmittable to the second pickup roller 89 by engaging the switch gear 121 with the third transmission gear 125 (although only a reverse rotation of the LF motor 107 is actually transmittable due to presence of the planetary gear and arm). In the multifunction apparatus of the modification contrast, on the other hand, the second state is established when the switch gear 121 is located at the position corresponding to the spacer 200, and thus simply and merely a rotation of the LF motor 107 is not transmitted to the first pickup roller 25.
According to the multifunction apparatus 1 of the embodiment and its modification, there is provided a simple arrangement for supplying a recording sheet 9 from the sheet supply tray 20 by the first pickup roller 25 on the basis of a forward rotation of the LF motor 107, and feeding the recording sheet 9 by the feeder roller 78 and the pinch roller 79 on the basis of a reverse rotation of the LF motor 107. Further, in the case where the multifunction apparatus 1 is designed to be able to optionally include the sheet supply cassette 11 and others, it is not necessary to modify the control routine depending on whether the optionally includable members are actually included or not.
Although there has been described one embodiment of the invention and its modification, it is to be understood that the invention is not limited to the details thereof but may be otherwise embodied with various other modifications and improvements that may occur to those skilled in the art, without departing from the scope and spirit of the invention defined in the appended claims.
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| 2006-352870 | Dec 2006 | JP | national |
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