1. Field of the Invention
The present invention relates to a feeding apparatus for feeding a recording medium such as a sheet material, a film material or a cut paper sheet one by one, and a recording apparatus equipped with such feeding apparatus.
2. Related Background Art
As a recording apparatus for recording a character or an image on a recording medium such as a cut paper sheet, there have conventionally been known an ink jet recording apparatus, a thermal transfer recording apparatus, an electrophotographic recording apparatus etc.
Among these, a smaller configuration of the entire recording apparatus and a lower production cost are requested for the ink jet recording apparatus and the thermal transfer recording apparatus as they are often used in personal applications.
Referring to
A configuration executing such elevation and lowering of the pressure plate in synchronization with a rotating operation of the feeding roller shaft is disclosed for example in Japanese Registered Patent No. 3090161.
In an initial operation state of the ASF 201, the feeding roller shaft 203 is in such a rotational position that the sensor masking portion 204 masks the transimission photosensor 205. In such state the pressure plate 210 is separated from the feeding rubber 206. In case it is in a non-masking position, an initializing operation is executed by an initialization signal from the main body of the ink jet recording apparatus. In case it is in a masking position, after the entry of a recording signal, the feeding roller shaft 203 starts rotation and the pressure plate 210 approaches the feeding rubber 206, whereby the feeding rubber 206 comes into contact with the recording medium 200 thereby executing a feeding thereof. The recording medium 200 thus fed is separated into a sheet in a separating portion 208 and conveyed to the recording portion.
However, the prior recording apparatus described above has been associated with following drawbacks.
Firstly, in the prior recording apparatus, it is necessary to establish an initial position for the feeding operation, in order to prevent a frictional contact between the recording medium and the feeding roller rubber, and a position sensor is provided for this purpose. Therefore the prior recording apparatus requires a complex electrical structure with an increased production cost. Also since a drive control is executed for stopping a motor in response to a detection signal from the sensor, it is necessary to secure a precision in the stopping position of the motor. Therefore, a highly precise motor is required, leading to an increase in the production cost.
By forming the feeding roller rubber in a circular shape instead of the D-shape, it is no longer necessary to initialize the rotational position of the feeding roller rubber, but the position of the pressure plate needs to be initialized. In the prior configuration, a sensor is still required to initialize the pressure plate, thereby elevating the production cost as in the above-described configuration.
Secondly, in case the distance from the feeding roller rubber to the recording portion is made long, the feeding roller rubber is required to have a circumferential length at least equal to the feeding distance to the recording portion, so that it has to have a large diameter, thus increasing the dimension of the entire recording apparatus.
Particularly in an ASF of so-called cassette feeding type in which the recording media are set horizontally, instead of the above-described ASF which is provided in the conventional recording apparatus and in which the recording media are placed on a pressure plate in a state inclined from the horizontal direction, the diameter of the feeding roller directly influences the height of the entire recording apparatus. Therefore, such ASF is difficult to employ in realizing a recording apparatus of a reduced height, thus resulting in a large installation space.
Also, together with an increase in the size of the entire recording apparatus, an external casing, such as a cover, for the entire apparatus also becomes larger, thus resulting in an increase in the cost of the material for forming the external casing etc. and elevating the production cost.
Particularly in case of employing a feeding roller rubber of a D-shaped cross section for preventing frictional contact between the recording medium and the feeding roller rubber as in the prior recording apparatus described above, the circumferential length of the arched portion of the feeding roller rubber, other than the straight portion thereof, has to be made longer than the feeding distance to the recording portion. Therefore, an even larger diameter is required than in the feeding roller rubber of the circular shape, thus being difficult to use in realizing a recording apparatus of a reduced height.
Thirdly, the prior recording apparatus utilizes the biasing force of a compression coil spring provided at the rear side of the pressure plate, as pressurizing means for pressing the pressure plate to the feeding roller rubber. For this reason, a medium stacking portion for stacking the recording media becomes thicker by the length of such compression coil spring, thereby leading to an increase in the dimension of the entire apparatus. This drawback becomes more conspicuous, as in the case of the roller diameter mentioned above, in so-called cassette feeding in which the recording media are stacked horizontally.
In consideration of the foregoing, an object of the present invention is to provide a feeding apparatus, capable of reducing the dimension of the entire apparatus and the production cost thereof, and a recording apparatus utilizing the same.
The aforementioned object can be attained, according to the present invention, by a feeding apparatus including a feeding roller for feeding a recording medium, a pressure plate provided movably between a contact position pressed to the feeding roller and a separated position separated from the feeding roller, pressure plate pressing means which provides the pressure plate with a pressing load for contacting the pressure plate with the feeding roller, and a motor for generating a driving power for moving the pressure plate to the contact position and to the separated position and a driving power for rotating the feeding roller. The feeding apparatus of the present invention also includes first drive transmission means which rotates the motor in a forward direction to contact and separate the pressure plate with and from the feeding roller, then shifts the driving power to the pressure plate to a non-transmission state, rotates the motor in a reverse direction to again transmit the driving power to the pressure plate thereby returning the pressure plate to an initial separated state prior to the rotation in the forward direction and shifts the driving power to the pressure plate to a non-transmission state, and second drive transmission means which transmits the driving power from the motor to the feeding roller. Further, the feeding apparatus of the present invention includes medium separation means which is provided in a downstream side of a contact position between the pressure plate and the feeding roller in a conveying direction of the recording medium and which separates the recording media one by one, conveying means which is provided in a downstream side of the medium separation means, for conveying the recording medium, and control means which includes detection means for detecting arrival of a leading end of the recording medium at the conveying means and which reverses the motor after the detection of the leading end of the recording medium by the detection means.
The feeding apparatus of the present invention having the aforementioned configuration allows to dispense with phase detection means for detecting a rotational phase of the feeding roller and is capable of securely controlling the drive of the feeding roller.
Also the second drive transmission means provided in the feeding apparatus of the present invention transmits a driving power from the motor to the feeding roller through the first drive transmission means, and the feeding roller is rotated and stopped in synchronization with a transmission state and a non-transmission state of the driving power to the pressure plate. The feeding roller can therefore be rotated only during a period necessary for feeding. Consequently it is possible to securely control the rotational phase of the feeding roller without employing phase detection means, even in case the feeding roller has a non-circular cross-sectional shape, such as a D-shape.
The feeding apparatus of the present invention further includes a transfer roller positioned at a downstream side of the medium separation means and at an upstream side of the conveying means and serving to convey the recording medium, a pinch roller pressed to the transfer roller, and third drive transmission means for transmitting a rotary driving power from the motor to the transfer roller. The recording medium, fed by the feeding roller, can thus be transferred to the conveying means by means of the transfer roller and the pinch roller.
The third drive transmission means provided in the feeding apparatus of the present invention rotates the transfer roller in a direction for transferring the recording medium toward the conveying means, regardless whether the motor is rotated in the forward direction or in the reverse direction. Thus, even when the motor is reversed for transmitting the driving power so as to return the pressure plate to the separated position (initial position), the transfer roller does not rotate in the reverse direction but advances the recording medium in the feeding direction.
Also the third drive transmission means provided in the feeding apparatus of the present invention transmits the driving power from the motor to the transfer roller in a forward rotation state of the motor, and attains a non-transmission state of interrupting the transmission of the driving power in a reverse rotation state of the motor. In this manner, the transfer roller can be rotated by the conveying means when the motor is rotated in the reverse direction.
The feeding apparatus of the present invention further includes contact/separation means which contacts the transfer roller and the pinch roller when the motor is rotated in the forward direction and separates the transfer roller and the pinch roller when the motor is rotated in the reverse direction. Thus, the transfer roller and the recording medium can be maintained in a non-contact state after the leading end of the recording medium reaches the conveying means.
Also the pressure plate pressing means provided in the feeding apparatus of the present invention includes a spring for generating a contact load, and direction converting means which changes a direction of load substantially perpendicularly from a biasing direction of the spring to contact direction of the pressure plate to the feeding roller. Therefore, a length of the spring, in a direction of elastic deformation thereof, requires a smaller space in the stacking direction of the recording media (a direction perpendicular to the principal plane of the recording medium), thereby allowing to reduce the dimension of the feeding apparatus in the direction parallel to the stacking direction of the recording media and to reduce the dimension of the recording apparatus.
Also the pressure plate pressing means provided in the feeding apparatus of the present invention includes a first movable plate for moving the pressure plate, and a second movable plate for moving the first movable plate. The first and second movable plates are positioned parallel to the pressure plate when it is moved to the separated position. Therefore, the first and second movable plates for moving the pressure plate require a smaller space in the stacking direction of the recording media, thereby allowing to reduce the dimension of the feeding apparatus in the direction parallel to the stacking direction of the recording media and to reduce the dimension of the recording apparatus.
Further, the recording apparatus of the present invention includes recording means which executes a recording on the recording medium fed by the feeding apparatus of the present invention.
As explained in the foregoing, the feeding apparatus of the present invention includes a feeding roller for feeding a recording medium, a pressure plate provided movably between a contact position pressed to the feeding roller and a separated position separated from the feeding roller, pressure plate pressing means which provides the pressure plate with a pressing load for contacting the pressure plate with the feeding roller, a motor for generating a driving power for moving the pressure plate to the contact position and to the separated position and a driving power for rotating the feeding roller, first drive transmission means which rotates the motor in a forward direction to contact and separate the pressure plate with and from the feeding roller, then shifts the driving power to the pressure plate to a non-transmission state, rotates the motor in a reverse direction to again transmit the driving power to the pressure plate thereby returning the pressure plate to an initial separated state prior to the rotation in the forward direction and shifts the driving power to the pressure plate to a non-transmission state, second drive transmission means which transmits the driving power from the motor to the feeding roller, medium separation means which is provided in a downstream side of a contact position between the pressure plate and the feeding roller in a conveying direction of the recording medium and which separates the recording media one by one, conveying means which is provided in a downstream side of the medium separation means, for conveying the recording medium, and control means which includes detection means for detecting arrival of a leading end of the recording medium at the conveying means and which reverses the motor after the detection of the leading end of the recording medium by the detection means, and can thus dispense with a position sensor required for detecting an initial position of the pressure roller and a high-precision motor and can achieve an automatic initialization of the pressure plate by merely repeating the forward and reverse drives of the motor, to enable a next feeding operation, thereby realizing a reduction in the production cost.
Also the second drive transmission means provided in the feeding apparatus of the present invention transmits a driving power from the motor to the feeding roller through the first drive transmission means, and rotates and stops the feeding roller in synchronization with a transmission state and a non-transmission state of the driving power to the pressure plate, thereby rotating the feeding roller only during a period necessary for feeding. Therefore the feeding apparatus of the present invention can dispense with a position sensor for detecting the initial position of the pressure plate and the feeding roller and a high-precision motor and can achieve an automatic initialization of the pressure plate and the feeding roller by merely repeating the forward and reverse drives of the motor, to enable a next feeding operation, thereby realizing a reduction in the production cost.
The feeding apparatus of the present invention also includes a transfer roller positioned at a downstream side of the medium separation means and at an upstream side of the conveying means and serving to convey the recording medium, a pinch roller pressed to the transfer roller, and third drive transmission means for transmitting a rotary driving power from the motor to the transfer roller, and can thus set a feeding amount by the feeding roller at a feeding distance for the recording medium to reach the transfer roller, thereby allowing to reduce the diameter of the feeding roller and realizing reductions in the dimension and the production cost of the feeding apparatus.
The third drive transmission means provided in the feeding apparatus of the present invention rotates the transfer roller in a direction for transferring the recording medium toward the conveying means, regardless whether the motor is rotated in the forward direction or in the reverse direction, whereby, even when the motor is reversed for transmitting the driving power so as to return the pressure plate to the separated position, the transfer roller does not rotate in the reverse direction but advances the recording medium in the feeding direction. Therefore, in the reverse rotation state of the transfer roller, the recording medium is prevented from being pulled to the upstream side and being rubbed, whereby a recording apparatus of an excellent recording quality can be realized without a fluctuation in a recording start position or a damage of the recording medium.
Also the third drive transmission means provided in the feeding apparatus of the present invention transmits the driving power from the motor to the transfer roller in a forward rotation state of the motor, and attains a non-transmission state of interrupting the transmission of the driving power in a reverse rotation state of the motor, thereby rotating the transfer roller by the conveying operation of the conveying means when the motor is rotated in the reverse direction, whereby a recording apparatus of an excellent recording quality can be realized without a fluctuation in a recording start position or a damage of the recording medium.
The feeding apparatus of the present invention further includes contact/separation means which contacts the transfer roller and the pinch roller when the motor is rotated in the forward direction and separates the transfer roller and the pinch roller when the motor is rotated in the reverse direction, thereby maintaining the transfer roller and the recording medium in a non-contact state after the leading end of the recording medium reaches the conveying means, and preventing the conveying means from a load in an intermittent conveying the conveying means. Thus a recording apparatus of an excellent recording quality can be realized without white streaks or black streaks generated by a low feeding precision.
Also the pressure plate pressing means provided in the feeding apparatus of the present invention includes a spring for generating a contact load, and direction converting means which changes a direction of load substantially perpendicularly from a biasing direction of the spring to a contact direction of the pressure plate to the feeding roller, thereby allowing to reduce the dimension of the feeding apparatus in the direction parallel to the stacking direction of the recording media and to reduce the dimension of the recording apparatus.
Also the pressure plate pressing means provided in the feeding apparatus of the present invention includes a first movable plate for moving the pressure plate, and a second movable plate for moving the first movable plate. The first and second movable plates are positioned parallel to the pressure plate when it is moved to the separated position, thereby allowing to reduce the dimension of the feeding apparatus in the direction parallel to the stacking direction of the recording media and to reduce the dimension of the recording apparatus.
In the following, the present invention will be explained by specific embodiments thereof, with reference to the accompanying drawings.
(First Embodiment)
The cassette feeding unit 1, when the main body 100 of the recording apparatus is mounted by positioning thereon as shown in
As shown in
As shown in
On a bottom face of the cassette tray 4, a pressure plate 8 is rotatably provided. The pressure plate 8 is rendered rotatable, about a rotary center provided at an end and formed by rotary supporting portions 8a, 8b on a same axis, between a contact position contacted with a feeding roller rubber 29 to be explained later and a separated position separated from the feeding roller rubber 29.
On the pressure plate 8, a separating sheet 9 is fixed for example with a both-side adhesive tape. The separating sheet 9 is formed for example by a cork material and provides a frictional force to a recording medium positioned closest to bottom side of the cassette tray 4, thereby preventing so-called superposed feeding in which plural recording media are erroneously advanced. After plural recording media are stacked, the feeding cassette 3 is inserted and mounted in a main body portion 2 of the feeding unit to be explained later.
As shown in
On the separation base 17, there stand positioning pins 21, 22 by which the main body 100 of the recording apparatus is positioned relative to the cassette feeding unit 1, when the main body 100 of the recording apparatus is placed and mounted thereon. Also on the separation base 17, there are provided movable hooks 23, 24 which are biased in the illustrated positions by springs (not shown) and are rotated to engage with the main body 100 of the recording apparatus when it is placed. A rear button (not shown), when pressed in, rotates and unlocks the movable hooks 23, 24 against the elastic force of the springs, whereupon the main body 100 of the recording apparatus can be lifted and separated from the cassette feeding unit 1.
The separation base 17 is provided with a female connector 47, which engages and is connected with a male connector on a bottom face of the main body 100 of the recording apparatus when it is placed, whereby a power supply and a motor drive signal to be explained later are entered from the main body 100 of the recording apparatus to a circuit board (not shown).
As shown in
On the base plate 25, a grounding spring 28, to be contacted with a chassis portion to be explained later of the main body 100 of the recording apparatus, is fixed on the left-side cover 16 which is omitted in the drawing. A feeding roller rubber (feeding roller) 29 is pressed into a part of the axial direction of a feeding roller shaft 33. A transfer roller 32 is positioned at a downstream side of the feeding roller rubber 29 in a feeding direction of the recording medium 51, and is formed by two rubber roller portions integrally fixed on a metal rotary shaft. Pinch rollers 38 are provided in positions corresponding to the roller portions of the transfer roller 32, and are pressed to the roller portions by a spring shaft (not shown) under a pressing force of about 100 gf. The transfer roller 32 is rocked by a transfer roller rocking mechanism to be explained later, and is switched between a contact state and a non-contact state to the pinch rollers 38.
The unit main body portion 2 is provided with a feeding mechanism for feeding the recording medium 41 and a separating mechanism for separating the recording medium one by one. In the following, configurations of the feeding mechanism and the separating mechanism will be explained with reference to FIGS. 4 to 7.
The feeding mechanism provided in the unit main body portion 2 includes, as shown in
The separating mechanism constituting medium separating means provided in the unit main body portion 2 includes a separating pad 37 to be contacted with the recording medium 41, a separating pad holder 36 capable of rotating the separating pad 37 between a contact position contacted with the recording medium and a non-contact position separated therefrom, and a rocking plate 31 for rotating the separating pad holder 36.
The separating pad 37 is formed by a foamed urethane material having a friction coefficient of 1.1 or higher to the recording medium 41. The separating pad 37 is adhered, for example with a double-side adhesive tape, on the separating pad holder 36. The separating pad holder 36 is provided rotatably about a rotary shaft 40 provided on the separation base 17. In an initial state (
Below the separating pad holder 36, a separating pad shaft 35 is fitted in a hole provided in the separation base 17 and is rendered movable in a vertical direction in
The rocking plate 31 is provided rotatably about a rotary shaft 42 supported by the base plate 25. In a state shown in
The second pressure plate pressing plate 39 is supported, at a base end thereof, rotatably about a rotary shaft 43 provided on the base plate 25, and is maintained, at a front end portion 44, in contact with the first pressure plate pressing plate 30 as shown in
The first pressure plate pressing plate 30 is inserted, at a bent portion 45 formed at an end, into a hole in the base plate 25 and is rendered rotatable about such bent portion 45. Therefore, an upward rotation of the second pressure plate pressing plate 39 causes an upward rotation of the first pressure plate pressing plate 30. Since the first pressure plate pressing plate 30 is contacted with the pressure plate 8 as described above, the pressure plate 8 can be moved vertically between the contact position and the separated position by the rotation of the second pressure plate pressing plate 39.
Then, reference is made again to
As shown in
The control circuit portion 130 also controls an LF motor 131, a carriage 106 and a recording head 106a to be explained later.
An idler gear 51 meshes with a drive gear (not shown) on a rotary shaft of the stepping motor 50. As shown in
At first the first pendulum gear unit 53 will be explained with reference to
In the initial state, as shown in
The first pendulum gear unit 53 is rendered capable of a rocking motion about a rotation center of a solar gear 55, and rotatably supports planet gears 56, 65 meshing with the solar gear 55. Also in a position adjacent to the first pendulum gear unit 53, there is provided a rocking cam gear 58, which is provided at an end of a cam shaft 98 (cf.
In the initial position of the first pendulum gear unit 53, the planet gear 56 meshes with the rocking cam gear 58 through the solar gear 55. In the first pendulum gear unit 53, the rocking cam gear 58 is rotated by the rotation of the planet gear 56, and, when the rocking cam gear 58 is rotated to a position where the toothless portion thereof corresponds to the planet gear 56, the meshing state of the planet gear 56 and the rocking cam gear 58 is released. Therefore, even when the stepping motor 50 continues to be driven in the reverse direction, the driving power transmitted to the planet gear 56 is not transmitted to the rocking cam gear 58 to attain a power non-transmitting state, whereby the rocking cam gear 58 is stopped in a state shown in
In feeding the recording medium 41 by a forward rotation of the stepping motor 50 from the state shown in
In the first pendulum gear unit 53, as in the case where the stepping motor 50 is rotated in the reverse direction, the rocking cam gear 58 is rotated by the rotation of the planet gear 65, and, when the rocking cam gear 58 is rotated to a position where the toothless portion 64 thereof corresponds to the planet gear 65, the meshing state of the planet gear 65 and the rocking cam gear 58 is released. Therefore, even when the stepping motor 50 continues to be driven in the forward direction, the driving power transmitted to the planet gear 65 is not transmitted to the rocking cam gear 58 to attain a power non-transmitting state, whereby the rocking cam gear 58 is stopped in a state shown in
Thus, by rotating the stopping motor 50 in the forward direction and in the reverse direction, the planet gear 65 is reciprocated within a range of a rotation angle of 110°, and the rocking lever 61 is also reciprocated within a range of a rotation angle of 7.5°. The width of such rocking motion is determined by a mechanical configuration and does not require a precision in the stopping position of the stepping motor 50.
As shown in
As shown in
Therefore, the transfer roller 32, supported by the rocking levers 61, 96 respectively provided in the right-side chassis 48 and the left-side chassis 49, executes a rocking motion in a direction of approaching to and being separated from the pinch roller 38 by the rocking motion of the rocking levers 61, 96. The rocking lever 61, the rocking lever 96, the idler gear 51, the idler gear train 52, the first pendulum gear unit 53, the rocking cam gear 58 and the cam portion 60 constitute contact/separating means which contacts and separates the transfer roller 32 and the pinch roller 38.
Then, the other second pendulum gear unit 54 will be explained with reference to
The second pendulum gear unit 54 has a rocking center coaxial with the rocking center of the rocking lever 61. During a feeding operation in which the stepping motor 50 is rotated in the forward direction, the second pendulum gear unit 54 is rocked in a direction g1 in
When the stepping motor 50 is rotated in the reverse direction, the second pendulum gear unit 54 rocks in a direction g2 in
Thus, regardless of the rotating direction of the stepping motor 50 in the forward or reverse direction, the transfer roller gear 67 is constantly rotated in a direction (clockwise in
In the following, there will be explained the driving power transmission by the second pressure plate pressing plate 39 and the feeding roller shaft 33.
As shown in
As shown in
In the state shown in
As shown in
In this manner, the second pressure plate pressing plate 39 is given a load of about 1.3 kg by the pressure plate coil spring 90 through the wire 88, and, as explained in
When a feeding operation is initiated from the state shown in
In this state, the pressure plate cam gear 80 tends to rotate by the load of the spring, and, in order to avoid a situation where such load is transmitted to the pressure plate pendulum gear unit 75 to separate the planet gear 77 from the pressure plate cam gear 80 and to interrupt the transmission of the driving power, the pressure plate cam gear 80 is provided with a cam portion 80 also on a rear side thereof as shown in
The cam portion 85 is required only in a section in the contracting direction of the pressure plate coil spring 90, namely a section in which the pressure plate 8 is elevated to contact the feeding roller rubber 29, so that the cam portion 85 is provided corresponding to such section. In response to the continued rotation of the pressure plate cam gear 80, the second pressure plate pressing plate 39 is once elevated and is then lowered again. When the pressure plate cam gear 80 is rotated to a rotational position shown in
Within a period from the initial state shown in
In the following, there will be explained a schematic configuration when the main body 100 of the recording apparatus is mounted on the cassette feeding unit 1.
The main body 100 of the recording apparatus includes a recording portion for recording on the recording medium 41, a conveying portion for conveying the recording medium, fed from the cassette feeding unit 1, to the recording portion, and a discharge portion for discharging the recording medium 41, recorded in the recording portion, to the exterior of the apparatus.
As shown in
In the conveying path of the recording medium 41, for detecting a leading end and a trailing end thereof in the conveying direction, a PE (paper end) sensor lever 104 constituting detection means is provided rotatably. A lower end of the PE sensor lever 104 is rocked when a leading end or a trailing end of the recording medium 41 passes, and a transmissive photosensor 104a detects a movement of an upper end of the PE sensor lever 104, thereby detecting the passing time of the recording medium 41.
The recording medium 41 extracted by the feeding roller rubber 29 as explained in the foregoing, after separation into a single sheet, is transferred by the transfer roller 32 along a direction j in
In the following, there will be explained, with reference to
The operation starts from a step S0, and at first a step S1 causes the control means 130 to rotate the stepping motor 50 in the forward direction.
The forward rotation of the stepping motor 50 is transmitted, through the idler gears 51, 73 to the idler gear 74. The rotation of the idler gear 74 is transmitted through the solar gear 76 band the planet gear 77 of the pressure plate pendulum gear unit 75, to the pressure plate cam gear 80, which in response starts to rotate clockwise in
The forward rotation of the stepping motor 50 is also transmitted, through the internal gear portion 84 of the pressure plate cam gear 80 and the feeding idler gear 99, to the gear portion 33a of the feeding roller shaft 33, thereby rotating the feeding roller 29 and feeding the recording medium 41.
The forward rotation of the stepping motor 50 is also transmitted, through the idler gear 51 and the idler gear train 52, to the solar gear 55 of the first pendulum gear unit 53. The rotation of the solar gear 55 is transmitted to the planet gear 65 and the rocking cam gear 58, and the rotation of the cam portion 60 rotating integrally with the rocking cam gear 58 rotates the rocking lever 61 clockwise (
The forward rotation of the stepping motor 50 is also transmitted, through the idler gear 51 and the idler gear train 52, to the solar gear 54a of the second pendulum gear unit 54. The second pendulum gear unit 54 rotates in a direction g1 (
The recording medium 41 fed by the feeding roller 29 is conveyed, by the transfer roller 32 rotating in contact with the pinch roller 38, along a direction j in
After the recording medium 41 reaches the transfer roller 32, the cam portion 92 of the pressure plate cam gear 80 in rotation presses down the second pressure plate pressing plate 39, whereby the pressure plate 8 is lowered and the recording medium 41 is separated from the feeding roller rubber 29. The recording medium 41 is conveyed, by the transfer roller 32, toward the LF roller 102 along a curved conveying path 120 in the main body of the recording apparatus. The pressure plate cam gear 80 rotates and stops at a position where the toothless portion 81 is opposed to the planet gear 77. In this state, the pressure plate 8 is in a lowest position.
In a step S2, after the leading end of the recording medium 41 is detected by the PE sensor lever 104, the transfer roller 32 advances the recording medium 41 by a distance from the PE sensor lever 104 to the LF roller 102 plus 10 mm. In this state, the recording medium 41 impinges on a contact portion between the LF roller 102 and the pinch roller 103 and then forms a loop, thereby securely maintaining the leading end of the recording medium 41 parallel to the LF roller 102 and preventing so-called skewed recording. The recording medium 41 is conveyed by 300 mm at maximum, until the leading end is detected by the PE sensor.
A step S3 discriminates whether the leading end of the recording medium 41 is detected by the PE sensor, and, if not, the flow proceeds to a step S4 to restore the initial state by reversing the stepping motor 50 by the control circuit portion 130. Then a step S5 discriminates whether the feeding operation is of second time, and, if so, a step S13 displays an error message for absence of the recording medium on a display panel (not shown) provided on the recording apparatus. In case the feeding operation is not of second time, the stepping motor 50 is rotated in the forward direction again to start the feeding operation from the step S1.
On the other hand, in case the step S3 identifies that the leading end of the recording medium 41 is detected by the PE sensor, the transfer roller 32 conveys the recording medium 41 by a distance to the LF roller 102 plus 10 mm, and then a step S6 causes the control circuit portion 130 to rotate the stepping motor 50 in the forward direction and also to drive an LF motor 13 for rotating the LF roller 102. In this manner the LF roller 102 is matched with the transfer speed of the transfer roller 102 and the recording medium 41 is conveyed for 12 mm in synchronization by the transfer roller 32 and the LF roller 102.
A step S7 causes the LF roller 102 to convey the recording medium 41 further to a recording start position, then steps the LF roller 102 and simultaneously reverses the stepping motor 50 whereupon the pressure plate cam gear 80 is rotated by an angle of 40° thereby returning to the initial position and is thus stopped. In such initial state, the transfer roller 32 is separated from the pinch roller 38, and, because of absence of a pulling resistance from the upstream side to the intermittent conveying operation by the LF roller 102, the LF roller 102 can maintain a satisfactory accuracy of conveying. Then a step S8 repeats a conveying operation by the LF roller 102 and a recording operation by the recording head 106a associated with the scanning motion of the carriage 106, thereby executing a recording on the recording medium 41.
A step S9 discriminates whether the recording is terminated in one page, and, if not, the flow returns to the step S8 to continue the recording operation. In case the recording is to be terminated, after the trailing end of the recording medium 41 is detected by the PE sensor lever 104, a step S10 conveys the recording medium by 120 mm, thereby discharging the recording medium 41 from the recording apparatus. The conveying is executed for 600 mm at maximum, until the trailing end of the recording medium 41 is detected by the PE sensor. A step S11 discriminates whether the trailing end of the recording medium 41 is detected by the PE sensor, and, if not, a step S12 displays a jam error for a paper jamming, but, if detected, the recording medium is discharged by conveying over 120 mm, and the sequence is terminated in a step S14.
(Second Embodiment)
In the foregoing first embodiment, the rocking levers 61, 96 are used to rock the transfer roller 32 thereby avoiding a detrimental influence on the conveying operation by the LF roller 102, but it is not essential to completely rock the transfer roller 32 for removing the load of the transfer roller 32 as in the first embodiment.
In the right-side chassis 302, there is also provided a pendulum gear unit (third drive transmission means) 303 for transmitting the driving power to the transfer roller gear 300. The transfer roller gear 300 meshes with a planet gear 304 of the pendulum gear unit 303.
When the leading end of the recording medium 41 reaches the LF roller 107 and the stepping motor 307 is rotated in the reverse direction, the pendulum gear unit 202 is rocked in a direction k in
Therefore, during an intermittent conveying operation by the LF roller 107, the transfer roller 301 is driven by the LF roller 107. The transfer roller 301 can be driven satisfactorily, though an inertial load at such drive and a dynamic frictional load at the bearings in the left- and right-side chassis are added, since such additional loads are small.
Thus, in comparison with the first embodiment, the second embodiment allows to dispense with the rocking lever, the cam gear, the idler gear etc. for rocking the transfer roller thereby simplifying the entire configuration of the cassette feeding unit and the recording apparatus and reducing the production cost.
This application claims priority from Japanese Patent Application No. 2003-306413 filed Aug. 29, 2003, which is hereby incorporated by reference herein.
Number | Date | Country | Kind |
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2003-306413 (PAT. | Aug 2003 | JP | national |