Sheet feeding apparatus and image reading and recording apparatus provided with the same

A first sheet feeding device and a second sheet feeding device for feeding sheets stacked on a first stacking portion and a second stacking portion, respectively, are driven by a driving force generated by a drive source. A controller controls the drive source so that the magnitude of the driving force may differ between a case where the first sheet feeding device is driven and a case where the second sheet feeding device is driven.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a sheet feeding apparatus and an image reading and recording apparatus provided with the same, and particularly to a sheet feeding apparatus provided with first sheet stacking means and second sheet stacking means for stacking sheets thereon.

2. Related Background Art

There has heretofore been a sheet feeding apparatus for feeding a sheet provided with first stacking means and second stacking means for stacking sheets such as recording paper and originals thereon, and as such a sheet feeding apparatus, there is one provided, for example, in a printer enabling manual sheet feeding to be effected, and adapted to feed sheets stacked on the first stacking means and sheets manually stacked on the second stacking means to an image recording portion by an automatic sheet feeding mechanism and a manual sheet feeding mechanism, respectively.

Also, as another example, there is one provided in an image reading and recording apparatus integrally provided with an image reading portion for reading the image of an original and an image recording portion for recording (forming) an image on recording paper.

FIG. 19of the accompanying drawings schematically shows the construction of a facsimile apparatus adapted to record an image on a sheet by an ink jet recording process, which is an example of an image reading and recording apparatus provided with such a conventional sheet feeding apparatus, and in this facsimile apparatus, when an image is to be recorded on recording paper301which is a sheet, sheets of recording paper301placed on a first recording paper holding member303which is first stacking means are first separated and fed out one by one by a recording paper feeding roller304which is first sheet feeding means connected to a recording paper transporting motor (not shown) and a separating mechanism (not shown), thereafter the recording paper301is transported to an image recording portion306by feeding rollers305.

Next, in this image recording portion306, ink is discharged while an ink cartridge which is image recording means, not shown, is moved in a scanning direction, whereby an image is recorded on the recording paper. After the image has been thus recorded, the recording paper301is delivered out of the apparatus by delivery rollers307as indicated by the arrow B0.

On the other hand, when the image of a document302is to be read, documents302are first set a document holding member308which is second stacking means in a form rammed in a wedge shape formed by a document separating roller309and a separating piece313driven by a document separating and transporting motor (not shown), next, in this state, among the documents302stopped by the wedge shape, only the document which is in contact with the document separating roller309is separated and transported by friction from the original separating roller309which is second sheet feeding means rotated on the basis of an image reading command.

Next, the thus separated and transported document302is passed above a contact image sensor311which is reading means provided in an image reading portion while being nipped between document feeding rollers310and between a delivery roller312and a runner312aopposed thereto, whereby image information is read. After the image information has been thus read by the contact image sensor311, the document302is delivered out of the apparatus as indicated by the arrow A0.

In the facsimile apparatus of such a construction, in order to realize the downsizing and lower cost of the apparatus, a transport path for use in common as an original transporting path and a recording paper transporting path is shown in Japanese Patent Application Laid-Open No. H07-183990.

However, in the conventional sheet feeding apparatus and a facsimile apparatus (image reading and recording apparatus) provided with the same, when design is made such that document transport and recording paper transport are effected by one and the same drive source, if there is a difference between torque necessary to effect the document transport and torque necessary to effect the recording paper transport, there arises the problem that the noise and step-out by overtorque occur.

SUMMARY OF THE INVENTION

So, the present invention has been made in view of such circumstances, and an object thereof is to provide a sheet feeding apparatus in which noise and step-out can be prevented from occurring even when a single drive source is used, and an image reading and recording apparatus provided with the same.

Another object of the present invention is to provide a sheet feeding apparatus provided with first stacking means and second stacking means, first sheet feeding means and second sheet feeding means for feeding sheets stacked on the first stacking means and the second stacking means, respectively, a single drive source for generating a driving force for driving the first sheet feeding means and the second sheet feeding means, and controlling means for controlling the single drive source, wherein the controlling means controls the single drive source so that the magnitude of the driving force may differ between a case where the first sheet feeding means is driven and a case where the second sheet feeding means is driven.

Another object of the present invention is to provide an image reading and recording apparatus provided with first stacking means for stacking sheets thereon, first sheet feeding means for feeding the sheets stacked on the first stacking means, an image recording portion for recording images on the sheets fed by the first sheet feeding means, second stacking means for stacking documents thereon, second sheet feeding means for feeding the documents stacked on the second stacking means, an image reading portion for reading the images of the documents fed by the second sheet feeding means, a single drive source for generating a driving force for driving the first sheet feeding means and the second sheet feeding means, and controlling means for controlling the single drive source, wherein the controlling means controls the single drive source so that the magnitude of the driving force may differ between a case where the first sheet feeding means is driven and a case where the second sheet feeding means is driven.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

However, the dimensions, materials and shapes of constituent parts and the relative arrangement thereof or the like described in this embodiment is not intended to restrict the scope of the present invention thereto unless particularly specified.

FIG. 1is a cross-sectional view showing the construction of a facsimile apparatus which is an example of an image reading and recording apparatus provided with a sheet feeding apparatus according to the embodiment of the present invention.

InFIG. 1, the reference numeral100designates a facsimile apparatus which is provided with an image recording apparatus portion101provided with an image recording portion1A for recording an image on recording paper2which is a sheet, an image reading apparatus portion102provided with an image reading portion28for reading the image of a document12, a recording paper transport path R1which is a first transport path along which the recording paper2passes, a document transport path R2which is a second transport path along which the document12passes, and a common transport path49provided downstream of the recording paper transport path R1and the document transport path R2with respect to a transport direction.

On the common transport path49, there are provided a transport roller10which is common feeding means for transporting the document12and the recording paper2, and a delivery roller17which is common delivery means.

The construction of the image recording apparatus portion101will now be described.

The image recording apparatus portion101is provided with the image recording portion1A which will be described later, and in addition, a recording paper supply tray8which is first stacking means capable of plural sheets of recording paper2stacking and containing thereon, and a recording paper feeding portion600having a recording paper separating roller19rotated in the direction indicated by the arrow A as shown inFIG. 2, a pressure plate9located between the recording paper separating roller19and a base member35and pivotally supported on the base member35, a separating pawl31, etc.

The pressure plate9is designed to be pivotally moved in a vertical direction with the rotation of the recording paper separating roller19, by a cam (not shown) formed integrally with the recording paper separating roller19, to thereby bring the recording paper2into contact with, or space the recording paper2apart from the outer peripheral surface of the recording paper separating roller19.

Also, the separating pawl31serves to intercept the sheets of recording paper2stacked on the recording paper supply tray8. When the recording paper separating roller19is rotated, the uppermost recording paper2abeing in contact with the recording paper separating roller19is adapted to be transported over the separating pawl31by the friction thereof with the recording paper separating roller19.

The recording paper separating roller19which is first sheet feeding means is constituted by attaching a frictional elastic material, e.g. rubber, to two cylindrical portions formed on a shaft member formed of plastics so as to have a diameter larger than that of the shaft, and as shown inFIG. 3, the opposite end portions of the shaft member19care journalled to the opposite side portions35aand35bof the base member35, and one end thereof is connected to a drive motor20which is a single drive source shown inFIG. 4via recording drive transmitting means603shown inFIG. 4.

Also, the recording paper separating roller19is adapted to be stopped when in a standby state so that as shown inFIG. 5, the D-shaped cut-away portion19A thereof may be opposed to the recording paper, and to form a gap G for passing the document12therethrough between itself and a document lower guide member23for guiding the document12to the common transport path49as will be described later. When the recording paper2is to be transported, the recording paper separating roller19is adapted to be rotated so that the circumferential portion19B thereof may clear a cut-away50formed in the document lower guide member23which is shown inFIG. 6and protrude downwardly of the document lower guide member23, and contact with the uppermost recording paper2a(seeFIG. 5) of the recording paper stack placed on the pressure plate9.

Further, this recording paper separating roller19makes one full revolution, whereafter the cut-away portion19A becomes again opposed to the recording paper2and is returned to the standby state shown inFIG. 5wherein the pressure plate9has been depressed by a cam. Thus, when the transporting roller10is transporting the uppermost recording paper2a, the second and subsequent recording paper2does not contact with the recording paper separating roller19, and it becomes possible to effect the stable transport of the recording paper2.

Downstream of the recording paper separating roller19, as shown inFIG. 1, there is provided a paper edge sensor (PES) lever21for detecting the transport of the recording paper2(or the document12), and design is made such that if a PES215does not detect the passage of the recording paper2(or the document12) through the PES lever21even when the paper feeding operation is started, a paper refeeding operation is performed, and if the PES21does not yet detect the passage of the recording paper2(or the document12), the transporting operation is error-stopped and an error is displayed on a display portion509.

On the other hand, the common transport path49provided downstream of the recording paper transport path R1along which the recording paper2fed out by the recording paper separating roller19passes with respect to the transport direction is provided with a platen3functioning as a supporting surface for transporting the recording paper2, and an auxiliary platen member3aprovided downstream of the platen3and functioning as a supporting surface for the underside of the recording paper2subsequently to the platen3.

A plurality of ribs38(seeFIG. 8) are formed on the recording paper supporting surface of the platen3in the widthwise direction of the recording paper so that during the transport of the recording paper, the recording paper2may pass over the upper surfaces of these ribs38.

Also, the auxiliary platen member3acooperating with the platen3which is a supporting member to constitute a supporting portion for supporting the recording paper2is held on the platen3for pivotal movement in a vertical direction through a shaft3a1disposed in a recess (not shown) formed in the recording paper supporting surface of the platen3, and formed upstream of the opposite sides thereof with respect to the recording paper transport direction, and also is normally resiliently biased as by a spring58, and is held in a position in which the upper recording paper supporting surface thereof becomes flush with a recording paper supporting surface constituted by the upper surface of the platen3.

This auxiliary platen member3a, when pushed from above it by a CS holder26or the like beyond the biasing force of the spring58as will be described later, is adapted to pivotally move in a direction to sink by the order of 5 mm relative to the recording paper supporting surface of the platen3.

Further, the common transport path49, as shown inFIGS. 7 and 8, is provided with the transporting roller10journalled to the platen3, and the delivery roller17integrally molded with plastic and elastomer, and in addition, four pinch rollers16juxtaposed in the widthwise direction of the recording paper and being in contact with the transporting roller10, a pinch roller guide36for journalling the pinch rollers16thereto so as to bring the pinch rollers16into pressure contact with the transporting roller10, a plurality of spurs18being in contact with the delivery roller17, and a spur holder55shown inFIG. 9for journalling the spurs18thereto so as to bring the spurs into pressure contact with the delivery roller17.

The transport direction of the recording paper2by the transporting roller10and the pinch rollers16is set so as to be obliquely downward from the upstream side to the downstream side of the rollers, and the transport direction of the recording paper2by the delivery roller17and the spurs18is set so as to be obliquely upward from the upstream side to the downstream side of the rollers. Thus, in the common transport path49, the recording paper2is transported in the direction indicated by the arrow P while contacting with the upper surfaces of the platen3and the auxiliary platen member3a.

A recording paper transporting force F generated by the transporting roller10and the pinch rollers16is of such a degree of magnitude that the frictional resistance force between the back of an original lower guide member23shown inFIG. 5and the recording paper2can be neglected, but when recording paper feeding accuracy is affected thereby, a low-friction member such as a high molecular sheet may be stuck on the back of the original lower guide member23.

Also, inFIGS. 8 and 9, the reference numeral1designates an ink cartridge which is image recording means, and the image recording portion1A for recording an ink image on the recording material transported by the recording paper separating roller19, the transporting roller10or the delivery roller17is of an ink jet recording type which discharges ink from this ink cartridge1to thereby effect recording. This ink cartridge1is provided with a minute liquid discharge port (orifice), a liquid path, an energy acting portion provided in a portion of the liquid path, and energy generating means for generating liquid droplet forming energy made to act on liquid present in the acting portion.

The reference numeral4denotes a carriage carrying the ink cartridge1thereon and scanning in the widthwise direction orthogonal to the transport direction of the recording paper2, and this carriage4has connected thereto an endless timing belt6passed over a drive pulley, not shown, and a driven pulley5, and the carriage4can be reciprocally moved along a guide rail7provided in the upper portion of a chassis24by the drive pulley being rotatively driven by a carriage driving motor33shown inFIG. 4. When the carriage4is thus reciprocally moved, the ink is discharged from the ink cartridge1in conformity with image information, whereby an image is recorded on the recording paper2.

Now, this carriage4normally stands by in a standby position at one end (right end) of the guide rail7shown inFIG. 8, and when the carriage4is in such a standby position, the printing head, not shown, of the ink cartridge1is protected by a rubber member, not shown, so as not to dry. Also during an original image reading operation which will be described later, the carriage4stays in the standby position. Further., when the ink in the ink cartridge1has become exhausted, the ink cartridge1is removed toward this side in the position shown inFIG. 8to thereby effect the interchange thereof.

In the ink jet recording process, there may occur a state in which the ink cartridge1becomes incapable of discharging the ink due to the mixing of bubbles or dust with the inward part of the minute discharge port, or increased viscosity or the like resulting from the evaporation of an ink solvent, or a state in which the ink becomes unsuitable for recording, but in such case, a head recovery operation for refreshing the ink is performed to thereby eliminate the factors for faulty discharge.

On the other hand, inFIGS. 1 and 10, the reference numeral500designates a control substrate attached to the back of the chassis24for effecting the control of an entire system, and this control substrate500is connected to a drive motor20, a carriage driving motor33, a speaker, not shown, an operating portion508and the image reading portion28by a cable, not shown. This control substrate500is disposed in a V-shaped space surrounded by an inclined base member35and the chassis24and therefore, the space in the facsimile apparatus100is effectively utilized and the downsizing of the entire apparatus becomes possible.

Further, this control substrate500is connected to an electric power supply505shown inFIGS. 10 and 11for rectifying a primary voltage (AC commercial power supply), and an NCU substrate504to which a telephone line is connected and having a primary voltage portion before dropped in voltage, by a cable, not shown. The NCU substrate504and the electric power supply505are disposed in a space behind the inclined base member35and therefore, the space in the facsimile apparatus100is effectively utilized and the downsizing of the entire apparatus becomes possible.

The reference numeral503designates a shield metal plate covering the electric power supply505and the NCU substrate504disposed in the space S behind the base member35, and a noise the control substrate500receives from the electric power supply505and the NCU substrate504can be mitigated by this shield metal plate503. This shield metal plate503is fastened to a lower cover100A by a screw or the like and therefor, even if the apparatus should fall and a gap is formed above the lower cover10A, it will never happen that a user touches the NCU substrate504and the electric power supply505.

Now, in the present embodiment, this control substrate500, as shown inFIG. 2, is provided between a document tray11, the recording paper supply tray8and the image reading portion28, the image recording portion1A, and the recording paper transport path R1and the document transport path R2are adapted to join each other upstream of this control substrate500.

As described above, the control substrate500is provided between the original tray11, the recording paper supply tray8and the image reading portion28, the image recording portion1A, and the recording paper transport path R1and the document transport path R2are adapted to join each other upstream of the control substrate500, whereby the document12can be transported without interfering with the control substrate500and the movement area of the ink cartridge1. In other words, the document transport path R2can be provided without interfering with the control substrate500and the movement area of the ink cartridge1, whereby the downsizing of the facsimile apparatus100becomes possible.

FIG. 12is a control block diagram of the facsimile apparatus100according to the present embodiment. InFIG. 12, the reference character500adenotes a control portion mounted chiefly on the control substrate500, and this control portion is connected to the already described electric power supply505, the NCU substrate504to which a telephone506and its line are connected, the display portion509for displaying a substance or the like inputted from the operating portion508, the image reading portion28, the drive motor20, the carriage driving motor33and the PES21S for detecting the leading edge and trailing edge of the recording paper2, and to a roller position sensor (RPS)119for detecting the rotational phase of the recording paper separating roller19, a document sensor (DS)120for detecting the presence or absence of the document12, etc. A module (not shown) is mounted on the NCU substrate504.

Also, this control portion500ahas a CPU500nfor effecting the control of the entire apparatus, a ROM500fstoring various programs and various data therein, a RAM500gused as the work area of the CPU500nand also effecting the temporary preservation of various data including the number of recorded sheets, etc., a buffer memory500dstoring therein transmitted and received encoded image data, an encoding/decoding portion500cfor encoding image information to be transmitted by MH encoding or the like, and decoding the received encoded image data and converting it into image data, a line memory500bstoring therein the image of each line of the image data, etc.

This line memory500bare designed such that in the case of the transmission or copying of the document, image data corresponding to one line from the image reading portion28is stored therein, and in the case of the reception of image data, decoded image data corresponding to one line is stored therein, and design is made such that the various data stored in this line memory500bare outputted to the image recording portion1A, whereby image recording is effected.

In the present embodiment, a constant current type pulse motor is used as the drive motor20, and the driving of this drive motor20is effected by a signal outputted from the output port of the CPU500nbeing converted into a phase signal through a motor driver500j, and transmitted to the drive motor20.

In the present embodiment, design is made such that the transporting operation for the recording paper2, the already described head recovery operation, and the image reading operation of feeding and transporting the document12and at the same time, moving the image reading portion28as will be described later are performed by this drive motor20, thereby achieving a reduction in cost.

The control portion500awhich is controlling means for controlling the drive motor20so that the transporting operation for the recording paper2, etc. can be performed by a single drive motor20as described above is adapted to changeover-control drive changing-over means (not shown) to thereby selectively transmit the drive of the drive motor20to one of reading drive transmitting means604, recording drive transmitting means603and head recovery means605.

However, as will be described later, the transport of the recording paper2requires the feeding accuracy for each one line, and the necessary torque differs between the image reading operation and the recording operation/recovery operation. So, the control portion500a, when it enters the image reading operation, sends a changeover signal from the port of the CPU500nto a changing-over circuit500ihaving a circuit construction shown inFIG. 14which will be described later, and changes a reference current value to a driver500jto thereby change over the peak current of the driving current of the drive motor20.

Description will now be made of the image recording operation of the image recording apparatus portion101constructed as described above.

When an image signal is inputted from an external device, not shown, the recording paper separating roller19is rotated in the direction indicated by the arrow shown inFIG. 9, and along therewith, the pressure plate9is moved up by the action of a cam, not shown, formed integrally with the recording paper separating roller19, and the recording paper2comes into contact with the outer peripheral surface of the recording paper separating roller19. Thereby, the uppermost recording paper2aon the recording paper supply tray8which is in contact with the recording paper separating roller19is transported over the separating pawl31and to the common transport path49by the friction thereof with the recording paper separating roller19.

Next, the recording paper2athus transported to the common transport path49is nipped between the transporting roller10journalled to the platen3and the four pinch rollers16, as shown inFIG. 9, and passes a recording paper supporting surface which is the upper surface of a supporting portion constituted by the platen3and the auxiliary platen member3a.

When the recording paper2athus passes the recording paper supporting surface, the ink is discharged from the ink jet cartridge1carried on the carriage4scanning (reciprocally moved) in the widthwise direction of the recording paper2a, in conformity with image information, whereby an image is recorded on the recording paper. After the image has been thus recorded, the recording paper2ais delivered out of the apparatus by the delivery roller17, as indicated by the arrow P.

Now, when the image is thus recorded in the image recording portion1A, when recording of one line is terminated on the recording paper2, the recording operation (ink discharge) is interrupted and the recording paper2is fed by a predetermined amount in a direction (sub-scanning direction) perpendicular to the direction of movement of the carriage4, and the image of the next line is recorded while the carriage4is again moved (caused to main-scan).

The feeding (transport) of the recording paper2is effected by the transporting roller10connected to the drive motor20being rotated by a predetermined amount, but if the amount of rotation of the transporting roller10becomes unstable due to a cause such as the faultiness of the motor and for example, the amount of rotation becomes excessive, a white blank portion will form in an image, and if the amount of rotation is deficient, the inconvenience of the overlap with the preceding line (black streak) will occur. Therefore, as already described, the amount of rotation of the transporting roller10requires high accuracy.

In the present embodiment, the printing operation for the recording paper2uses one side portion (right side portion)35bof the base member35inFIG. 3as the recording reference. Also, a first recording paper separating roller portion19aof the recording paper separating roller19is disposed at a location near this one side portion35b, e.g. distant by about 43 mm from the one side portion35b, and a second recording paper separating roller portion19bthereof is disposed at a location distant by about 189 mm from the one side portion35bso as to sandwich the document separating roller15. By thus disposing the first recording paper separating roller portion19aand the second recording paper separating roller portion19, it is possible to cope with the recording paper2of various sizes from postcard size to A4 size.

The image reading apparatus portion102will now be described.

The image reading apparatus portion102is provided with the image reading portion28which will be described later, and in addition, a document tray11which is second stacking means capable of containing a plurality of documents12, and a document feeding portion40for transporting the documents12set on the document tray11to the image reading portion28, as shown inFIGS. 1 and 10, and this document feeding portion40is disposed upstream of the recording paper feeding portion600with respect to the transport direction of the document, and has a document separating roller15which is second sheet feeding means, and a document feeding runner52, a document transporting roller S, a document upper guide14, etc. for transporting the separated document further downstream.

A sheet feeding apparatus103for feeding the document12and the recording paper2to the image reading portion28and the image recording portion1A is constituted by the document tray11, the document separating roller15, etc. and the already described recording paper supply tray8, the recording paper separating roller19, etc.

InFIG. 10, the reference numeral501designates a runner supporting metal plate provided between the control substrate500and the document feeding portion40for supporting the document feeding runner52for contacting with a document transporting roller51which is the sheet transporting roller of the present invention to thereby transport the document12separated by the document feeding portion40further downstream, and this runner supporting metal plate501is disposed so as to have its opposite ends supported by the base member35. Also, this runner supporting metal plate501serves to hide the document separating roller15and the document transporting roller51having rubber of low flame retardancy from the control substrate500.

The document transporting roller51is disposed between the document separating roller15and the transporting roller10, has a cylindrical frictional elastic member mounted on a shaft member formed of a metal, and is rotatably journalled to the base member35, and one end of the shaft is connected to the reading drive transmitting means604(seeFIG. 12). That is, the document transporting roller51is driven by the drive motor20. Also, the document feeding runner52is biased toward the document transporting roller51by a document feeding runner spring (not shown) and gives birth to a document transporting force.

The document feeding portion40uses one side of the document12as the reference, and in the present embodiment, as shown inFIG. 13, the inner wall of the left side plate11aof the document tray11is the document reference.

The document separating roller15is formed with a cylindrical frictional elastic member mounted on a shaft member15aformed of a metal, and is rotatably journalled to the opposite side portions35aand35bof the base member35, as shown inFIG. 3. One end of the shaft15aof this document separating roller15is connected to the drive motor20(seeFIG. 4) through the reading drive transmitting means604(seeFIG. 12) and drive changing-over means (not shown).

This drive changing-over means, as already described, is adapted to be changed over by the control portion500a(seeFIG. 12), and in the case of the image recording operation, transmit the drive of the drive motor20to the recording drive transmitting means603to thereby drive the recording paper separating roller19, and in the case of the image reading operation, transmit the drive of the drive motor20to the document separating roller15and the image reading portion28through the reading drive transmitting means604.

Further, the document separating roller15, as already described, is disposed between the roller portions19aand19bof the recording paper separating roller19(seeFIG. 3), and in the present embodiment, substantially centrally in the widthwise direction of the document, and by the document separating roller15being disposed at such a location, the skew feed of the document12can be mitigated.

InFIG. 5, the reference numeral13designates a separating piece brought into pressure contact with the document separating roller15by a separating spring37a, and this separating piece13is formed of a material of a high coefficient of friction such as rubber, and is held by a separating piece supporting member37pivotally supported on a document lower guide member23for directing the document12fed out by the document separating roller15toward the common transport path49. Also, the reference numeral27denotes an auxiliary document transporting member for urging the document12against the document separating roller15to thereby perform an auxiliary operation for the separation of the document.

When the documents12are set on the document tray11provided with such a separating piece13, etc., the documents12have their leading edges stopped by a wedge shape formed by the separating piece13and the document separating roller15, and when the document separating roller15is thereafter rotated, only the uppermost document12aof the documents12stopped by the wedge shape is transported by the friction thereof with the document separating roller15.

Now, the separating piece13is biased against the document separating roller15by the separating spring37aand therefore, the document12is transported while receiving the load by the document separating roller15and the separating piece13. When the document12is thus transported while receiving the load, load torque increases and a stretched image will come to occur.

So, in the present embodiment, a document transporting roller51which is intermediate feeding means is disposed between the document separating roller15and the transporting roller10, as shown inFIG. 10, and as already described, during the image recording operation, for example, a changeover signal is changed over from High to Low to thereby drive the drive motor20by motor torque higher than during the recording paper transport, whereby the transporting force of the document transporting roller51is adapted to become higher than the load.

As described above, the document transporting roller51is disposed between the document separating roller15and the transporting roller10, and the transporting force of the document transporting roller51is made greater than the load, whereby the stretched image can be prevented.

Now,FIG. 14shows the construction of the changing-over circuit500idisposed between the CPU500n(seeFIG. 12) and the drive motor to effect the changeover of the peak current (value) of the driving current of such a drive motor20, and as shown inFIG. 14, the changing-over circuit500iis comprised of a transistor Q1and three resistors R1-R3.

In the present embodiment, the resistor R1is set to 1.5 kΩ, the resistor R2is set to 2.2 kΩ, and the resistor R3is set to 1.5 kΩ. Also, Rs designates a current value detecting resistor connected to the driver500j, and this current value detecting resistor Rs is set to 0.51 kΩ.

Here, a peak current value PA, i.e., a motor current value (A), applied to the drive motor20is represented by the following expression, for example, in the present embodiment when a reference voltage to the driver500jis defined as Vref.
PA=Vref/(10×Rs) . . . (10 is a constant)

Also, during the recording operation and during the recovery operation, the changeover signal from the port in the CPU is High as already described, whereby the transistor Q1is in its ON state.

When in this state, it is assumed that R0=(R2×R3)/(R2+R3), Vref is 1.86V[=5V×R0/(R0+R1)] and therefore, the motor current value PA is about 0.36 mA from the foregoing expression.

On the other hand, during the reading operation, the CPU500nrenders the changeover signal from the port Low, and renders the transistor Q1OFF. Vref at this time is 2.5V[=5V×R3/(R1+R3)] and therefore, the motor current value PA is about 0.49 mA.

As described above, the changeover signal from the CPU500nis rendered High during the recording operation and during the recovery operation, and is rendered Low during the image reading operation, and the reference voltage to the driver500jis changed to thereby change over the peak current value of the drive motor20. By effecting such current control conforming to the necessary torque, silencing becomes possible and also, the step-out of the drive motor20can be prevented.

Also, a document upper guide14is disposed above the document lower guide member23which is a lower guide member and constitutes the upper surface of the document transport path R2, and this document upper guide14which is an upper guide member is formed into a strip shape, and has its upper end pivotally supported on the shaft portion15aof the document separating roller15, as shown inFIG. 5, and hangs down onto the document lower guide23from gravity and constitutes the upper surface of the document transport path R2.

This document upper guide14is formed of resin or the like having good slidability and is light in weight, and is pivotally movable about the shaft portion15aof the document separating roller15with a light force and therefore, when the document12is being transported between the document upper guide14and the document lower guide member23by the document transporting roller51or the transporting roller10, the document upper guide14is adapted to be pushed upwardly with the document separating roller15as the center of rotation by the stiffness of the document12and the fluttering of the leading edge or the trailing edge thereof. By the document upper guide14being thus pushed up, the document transport path R2is secured.

When the document upper guide14is thus pushed up, the document upper guide14is upwardly flexed (deformed) and the upper surface of the lower portion thereof comes into contact with the shaft portion19cof the recording paper separating roller19, but design is made such that even in a state in which the document upper guide14is thus in contact with the shaft portion19cof the recording paper separating roller19, the guide surface of the document upper guide14is located more toward the document transport path R2than the cut-away portion19A of the recording paper separating roller19.

That is, even if the document upper guide14is pushed up by the document12when the document12is transported, the document upper guide14comes to be positioned at a location whereat the recording paper separating roller19does not contact with the document12, by (the shaft portion19cof) the recording paper separating roller19. Thus, when the document12is transported, the recording paper separating roller19does not contact with the document12and does not hamper the transport of the document12.

Also, the recording paper separating roller19, as already described, has its shaft portion.19cformed of a flexible material such as plastic and therefore, the recording paper separating roller19may sometimes be downwardly flexed by its own weight, but even in such a case, the document upper guide14contacts with the shaft portion19cof the recording paper separating roller19in its flexed state and therefore, the relative positional relation between the recording paper separating roller19and the document upper guide14is maintained, and it never happens that the cut-away portion19A of the recording paper separating roller19protrudes into the document transport path R2. Thereby, the document12is fed reliably and stably without contacting with the recording paper separating roller19.

Further, as already described, the roller guide63formed of a low-friction material is attached to the cut-away portion19A of the recording paper separating roller19and therefore, faulty transport can be prevented even when the document12contacts with the roller portion19aof the recording paper separating roller19.

A document slider30which is regulating means for effecting the position regulation of the document12in the widthwise direction thereof orthogonal to the document transport (feed) direction, and preventing the skew feed of the document12is provided on the document tray11for movement in accordance with the width of the document, as shown inFIG. 15. Also, inFIG. 15, the reference character11A designates the document stacking portion of the document tray11, and the reference character11B denotes a document supporting portion provided on the document tray11to support the upper portion of the document, and the document stacking surface of the document tray11is constituted by the document stacking portion11A and the document supporting portion11B.

The image reading portion28, as shown inFIG. 7, is disposed between the transporting roller10and the delivery roller17and in the movement route of the carriage4so as to be opposed to the platen3, and is adapted to read the upper surface of the document12being transported, and by the image reading portion28being thus provided in the movement route of the carriage4, the downsizing of the facsimile apparatus100can be achieved.

In other words, the image reading portion28and the image recording portion1A are juxtaposed, and during the reading operation, the image reading portion28is moved into the movement area of the carriage4(image recording portion1A), and during the image recording operation, the image reading portion28is moved to a standby position outside the movement area of the carriage4, whereby the movement space of the carriage4can be effectively used not only during recording but also during image reading, whereby the downsizing of the apparatus can be achieved.

This image reading portion28is provided with a contact image sensor (hereinafter referred to as a CS)22which is image reading means, a CS holder26which is a holding member for holding the CS22, and a white reference member25held by the CS holder26while being opposed to the CS22.

The CS22is contained in a recess formed in the CS holder26so that the sensor surface thereof may be outer, and is fixed by a screw (fastening member) (not shown). Also, the white reference member25is formed by a white sheet attached to a metal plate, which is provided with a flat surface to which the white sheet is attached, and bent portions formed on the lengthwisely opposite end portions thereof.

These bent portions are formed with apertures, and a shaft formed in the CS holder26is engaged with these apertures to thereby support the white reference member25for pivotal movement relative to the CS holder26and the CS22. This white reference member25is biased toward the CS side by a torsion coil spring (not shown).

Also, this white reference member25has, on the outer side thereof in the widthwise direction of the document, a projection (not shown) abutting against the CS22while being biased against the CS22, and by this projection, a gap G1(reading transport path) enabling at least one document to pass therethrough is adapted to be formed between the sensor surface of the CS22and the white sheet of the white reference member25.

Now, the white reference member25cooperating with the CS22to form the reading transport path can assume a normal position in which it is biased by the torsion coil spring to thereby form the gap G1enabling at least one document to pass therethrough, and a cleaning position in which against the torsion coil spring, the white reference member25has been pivotally moved away from the CS22.

When the white sheet of the white reference member25or the reading surface of the CS22is stained with the ink of the image recording portion1A, the user can move the white reference member25to the cleaning position to thereby simply clean the stained portion.

A hollow boss26ais formed on one side wall surface of the CS holder26in the lengthwise direction thereof, and a boss68bis formed on the other side wall surface of the CS holder26, and a boss68aformed on a CS holder supporting member68mounted on the platen3as shown inFIG. 16is engaged with the hollow boss26aon the one side wall surface, and a bearing portion69formed on the platen3is engaged with the boss68bformed on the other side wall surface.

These right and left engaging portions are on the same shaft, whereby when in the case of image recording shown inFIG. 9, the carriage4has been moved in the scanning direction, the CS holder26is adapted to be movable from a first position (standby position) in which it does not contact with the carriage4to a second position (reading position) shown inFIG. 2wherein a document reading transport path formed in the movement space of the carriage4by the gap between the reading surface of the CS22and the white reference member25and the recording paper supporting surface formed by the platen3are flush with each other.

Further, the horizontal position of the CS holder26is designed such that in a state in which, when viewed from the delivery direction, the ink cartridge1is in the capping position (seeFIG. 8) at one end (right end) within the movement range of the carriage, the CS holder26can be moved to the second position.

Also, the upstream side of the metal plate of the white reference member25with respect to the document transport direction is of a comb-tooth shape, and the ribs38of the platen are adapted to come into among the comb teeth, and a bent portion for increasing the strength in the lengthwise direction is formed on the downstream side of the metal plate of the white reference member25with respect to the document transport direction.

When the CS holder26is to be moved to the second position, this bent portion pushes down the auxiliary platen member3apivotally supported as already described, whereby the CS holder26can be moved to the second position. Thereby, during document reading, the reading transport path formed between the transporting roller10and the delivery roller17by the white reference member25and the CS22and the recording paper supporting surface formed by the platen3become flush with each other.

Also, on one end portion (widthwisely left end portion) of the CS holder26, there is disposed CS driving means609connected to the drive motor20through drive changing-over means (not shown) and CS drive transmitting means608shown inFIG. 17, and the CS holder26can be moved to the first position or the second position by the drive of the drive motor20through the CS driving means609.

For example, the CS holder26is biased in a counter-clockwise direction as viewed inFIG. 1by a CS push-up spring (resilient member) so as to be held in the first position in the standby state of the apparatus, but when the image reading operation is started, the drive of the drive motor20is transmitted to the reading drive transmitting means604by the drive changing-over means, whereby the document transport driving means609rotates the document separating roller15to thereby perform the document feeding operation, and also the CS drive transmitting means608rotates a push-down spring610provided on the shaft of the CS driving means609in a clockwise direction as viewed inFIG. 1, and moves the image reading portion28to the second position by such torque as overcomes the reaction force of the CS push-up spring.

The CS driving means609utilizes the sliding torque of a spring clutch and therefore, when a certain phase is reached, the clutch is disconnected so that the image reading portion28may be pushed in a clockwise direction as viewed inFIG. 1by constant torque. By the gear ratio between the document transport transmitting means607and the CS drive transmitting means608and the roller diameter being adjusted, the CS holder is set so as to be moved to the CS holder second position (reading position) before the document12arrives at the transporting roller10.

Description will now be made of the image reading operation of the image reading apparatus portion102constructed as described above.

When the reading operation is started with the document12set on the document tray11, the drive changing-over means is first changed over by the control portion (seeFIG. 12) to thereby transmit the drive of the drive motor20to the document separating roller15and the document transporting roller51through the reading drive transmitting means604. Thereby, the document separating roller15and the document transporting roller51are rotated in the direction indicated by the arrow shown inFIG. 2, and the documents12set on the document tray11are separated and fed out one by one by the thus rotated document transporting roller51and document separating roller15and the separating piece13.

At this time, the phase of the recording paper separating roller19disposed downstream of the document separating roller15with respect to the feeding direction as already described in the rotational direction thereof is in its initial state, and the gap G sufficient to pass a document therethrough is formed between the cut-away portion19A of the roller portion19aof the recording paper separating roller19and the document lower guide member23(seeFIG. 5).

Also, the document separating roller15is thus rotated and also the CS driving means609is operated through the CS drive transmitting means608, and the CS holder26held in the first position (standby position) as shown inFIG. 9in the standby state of the apparatus is pivotally moved in the direction indicated by the arrow.

When the CS holder26is thus moved to the second position, the clutch connecting the CS driving means609and the CS drive transmitting means608together is disconnected and the CS holder26is stopped, and also is biased in that position by the CS push-down spring610. Also, at the same time, the CS holder26pushes down the auxiliary platen member3a, whereby a reading transport path flush with the recording paper supporting surface constituted by the platen3is formed between the transporting roller10and the delivery roller17.

Next, the document12separated and fed out one by one, like the recording paper2, is guided by the platen3, the pinch roller guide36and the upper guide42with the underside thereof supported by the document lower guide member23, and is transported to the nip between the transporting roller10and the pinch rollers16while depressing the PE sensor lever21.

When the PES lever21is thus depressed, a detection signal is inputted from the PES21S to the control portion, which in turn detects the leading edge of the document12on the basis of this detection signal, and finds the reading position on the document12.

Next, the document12transported to the transporting roller10and the pinch rollers16is nipped by the transporting roller10and the four pinch rollers16, and passes the reading transport path formed by the CS22and the white reference member25and has its image data read by the CS22during this passage. When the most trailing edge of the document12is read, the document12is delivered out of the apparatus by the delivery roller17.

When the document12is thus delivered, the drive motor20is reversely rotated, whereby the CS driving means609and the CS drive transmitting means608are connected together by the clutch, and the CS holder25is moved to the first position by the already described CS push-up spring.

Also, with the movement of this CS holder26to the first position, the auxiliary platen member3ais pushed up by the biasing force of the spring58, whereby a flush recording paper supporting surface is formed by the recording paper supporting surface of the auxiliary platen member3aand the recording paper supporting surface of the platen3. Lastly, the drive of the drive motor20is changed over to a recording mode by the drive changing-over means, and the apparatus assumes a standby state.

Now, in the present embodiment, the separating piece13cooperating with the document separating roller15to separate and feed out the documents12set on the document tray11one by one is disposed in a space avoiding the interference with the document lower guide member23, the recording paper separating roller19and the control substrate500fixed to the back of the printer chassis, as shown inFIG. 1.

Moreover, to prevent the document12from protruding from the apparatus as much as possible, it is preferable for this separating piece13to be disposed at the lowest possible position in this space. When the separating piece13is disposed at such a position, the angle of the separating piece13becomes nearly parallel to the stacked recording paper2, as shown inFIG. 18. In the present embodiment, the separating piece13is disposed so as to form an angle of about 60° with respect to a horizontal plane.

On the other hand, when the separating piece13is disposed at such an angle, to prevent the double feed or the like of the document12, it is necessary that the entry angle of the leading edge of the document be an angle sharper by 10° to 30° than the angle of the separating piece13, i.e., 70° to 90° with respect to the horizontal plane. When the entry angle of the leading edge of the document is such a sharp angle, there is the possibility that the load of the document itself concentrates in the leading edge portion of the document12, whereby the document12is outwardly flexed and buckled on the document tray11from gravity or the upper end portion thereof is inclined forwardly (toward the document separating roller side).

So, in the present embodiment, the document stacking surface of the document tray11constituted by a document stacking portion11A and a document supporting portion11B shown inFIG. 15is formed so that an angle A1formed with respect to the vertical direction by the upper end of the document stacking surface (document supporting portion11B) may be greater than an angle A2formed with respect to the vertical direction by the lower end of the document stacking surface (document stacking portion11A).

As described above, the document stacking surface of the document tray11is made into such a round (curved) shape that for example, the angle gradually becomes from the angle A2to the angle A1so that the upper end portion side may be greater in the angle formed with respect to the vertical direction than the lower end portion side, whereby it never happens that the load of the document itself concentrates in the leading edge portion of the document12. Thereby, the possibility that the document12is buckled or is inclined forwardly becomes null, and as the result, the stacking performance for the documents12can be maintained and the documents12can be fed reliably.

This effect arises if the angle difference (A1−A2) between the angle A1of the lower end of the document stacking surface near the separating portion and the angle A2of the upper end of the document stacking surface is 20° or greater, but if this angle different is 70° or greater, the smooth feeding of the document12becomes difficult. Therefore, in the present embodiment, this angle difference (A1−A2) is about 50°, whereby the document12can be smoothly fed.

Even when as described above, the separating piece13is disposed at an angle of about 60° with respect to the horizontal plane and the document tray11is disposed so that the angle difference (A1−A2) may be about 50°, as shown inFIG. 18, the angle formed with respect to the vertical direction by the lower end portion of the document stacking surface of the document tray11is made smaller than the angle formed with respect to the vertical direction by the lower end portion of the sheet stacking surface of the recording paper supply tray8. Thereby, the documents12can be set on the document tray11without being hindered by the recording paper2stacked on the recording paper supply tray8, and also the downsizing of the apparatus becomes possible.

Now, in the present embodiment, the document tray11is formed of a transparent material, whereby the presence or absence of the recording paper2can be confirmed without the document tray11being removed. Even if the document tray is formed by a wire or the like instead of the transparent material, a similar effect can be obtained.

Also, this document tray11is detachably mounted on the facsimile apparatus100, and as shown inFIG. 15, a mounting projection301is provided on the lower end of the document tray11. This projection301is inserted into an insertion port provided in an outer cover (not shown), whereby the document tray11can be simply mounted on the facsimile apparatus100.

Further, as described above, the document tray11can be simply mounted on the facsimile apparatus100, whereby when the absence of the recording paper2is confirmed, it becomes possible to effect the loading of the recording paper2easily.

Now, as shown inFIGS. 15 and 16, a buckle preventing portion300awhich is a suppressing portion for suppressing the documents12stacked on the document stacking surface from being buckled is provided in opposed relationship with the document stacking surface, and a buckle preventing portion300bwhich is a suppressing portion for preventing the documents12from being buckled is provided on the slider30in opposed relationship with the document stacking surface. The documents12are prevented by these buckle preventing portions300aand300bfrom being buckled, whereby the stacking performance for the documents can be maintained.

Also, in the present embodiment, the upper end portion11aof the document stacking surface (document supporting portion11B) is designed such that the position of the upper end12a1of the lowermost one of the stacked documents12can secure a sufficient distance L so as not to interfere with the recording paper2stacked up to a maximum number of stackable sheets, whereby the documents12and the recording paper2can be stably separated and fed.

The upper end portion11aitself of the document stacking surface is also designed to be capable of securing a sufficient distance L1 so as not to interfere with the recording paper2stacked on the recording paper supply tray8up to the maximum number of stackable sheets, whereby the documents12and the recording paper2can be stably separated and fed.

As described above, the upper end11a(of the document stacking surface) of the document tray11disposed above the recording paper supply tray8, or the documents12stacked on the document tray11are positioned so as not to interfere with the recording paper2stacked on the recording paper supply tray8, and also the document stacking surface of the document tray11is formed so that the angle formed with respect to the vertical direction by the document stacking surface may be greater on the upper end portion side than on the lower end portion side, whereby the recording paper2and the documents12can be reliably separated and fed.

As described above, as in the present embodiment, the auxiliary platen member3aconstituting the supporting portion for supporting the recording paper2is retractably provided in the common transport path49, and when the image of the document is to be read, (the CS22held by) the CS holder26is moved to a position in which a document transport path is formed in the common transport path and the reading of the image of the document is possible while the auxiliary platen member3ais retracted from the common transport path, whereby the downsizing and the recording and reading accuracy of the apparatus are maintained, and yet the contamination of the image reading portion28by the ink can be prevented.

Also, as already described, the separated recording paper2and document12are transported by the common transporting roller10and delivery roller17, whereby there is not the necessity of discretely providing a reading drive motor and a document transporting mechanism and thus, a reduction in cost is realized and the downsizing of the entire apparatus can be achieved.

Further, even when there is adopted the image recording portion1A of a construction using the ink jet recording process advantageous in such points as downsizing and running cost, the CS22is designed to be retracted from the common transport path49during the image recording operation as in the present embodiment, whereby the contamination by ink mist and ink leakage during the recording operation can be prevented and also, limitations in layout become less and the degree of freedom during design can be increased.

Furthermore, during the image recording operation, the CS22is adapted to be retracted from the common transport path49, whereby even if the jam or the like of the recording paper occurs in the image recording portion1A, it is possible to prevent the occurrence of the trouble that unfixed ink adheres to the reading surface of the CS22or the white reference member25. Also, by covering the reading surface of the CS22with the white reference member25, it is possible to greatly mitigate the contamination of the reading surface of the CS22by ink mist.

Also, when the document12is to be fed, the recording paper separating roller19is stopped at a position in which the cut-away portion19A faces the document lower guide member23, that is, does not come into between the document upper guide14and the document lower guide member23, whereby even if for example, the document12is being fed, it becomes possible to suitably feed the recording paper2.

Further, when the document12is to be fed, even if the document upper guide14provided above the document lower guide member23is pressed by the document12and is upwardly pivotally moved, this document upper guide14is made to abut against the shaft portion19cof the recording paper separating roller19and is positioned so that the cut-away portion19A of the recording paper separating roller19may not protrude into the document transport path R2, whereby the document12can be fed reliably and stably without contacting with the recording paper separating roller19.

Further, as in the present embodiment, the driving force is made greater when the drive motor20is controlled by (the CPU500nof) the control portion500ato thereby drive the document separating roller15than when the recording paper separating roller19is driven, that is, the driving force is made greater when the document12is fed than when the recording paper2is fed, whereby even when the transport of the document and the transport of the recording paper between which there is a difference in necessary torque are effected by the use of the single drive motor20, such inconveniences as noise and step-out can be prevented from occurring.

While in the present embodiment, description has been made of a case where the document tray11is disposed above the recording paper supply tray8and along therewith, the document separating roller51is provided upstream of the recording paper separating roller19, the present invention is not restricted thereto, but the recording paper supply tray8may be disposed above the document tray11and along therewith, the recording paper separating roller19may be provided upstream of the document separating roller51.

Further, while in the description hitherto made, description has been made of a case where the sheet feeding apparatus according to the present invention is provided in the facsimile apparatus, the present invention is not restricted thereto, but the sheet feeding apparatus may of course be provided for example, in a printer having an automatic paper feeding mechanism and a manual paper feeding mechanism. In such case, documents are not stacked on the second sheet stacking means as in the present embodiment, but recording paper in stacked on the second sheet stacking means.