JP2000255804A - Sheet feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device capable of reducing manufacturing cost and downsizing. SOLUTION: Absorbing disks 60a, 60b forming sheet supplying portions are connected to a three port type solenoid valve 74 through pipes 70, 72, respectively. A vacuum pump 78 is connected to the solenoid valve 74 through a pipe 76. When a recording sheet is absorbed on only one of the absorbing disks 60a, 60b, the solenoid valve 74 is turned on/turned off two or more times, which causes the recording sheet to be released from the absorbing disks 60a, 60b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for taking out a recording medium from a sheet accommodating means accommodating a sheet-like recording medium.

[0002]

2. Description of the Related Art For example, in an image recording apparatus for recording an image on a recording sheet, a magazine accommodating the recording sheet can be loaded in order to sequentially record images on recording sheets of different sizes. A configuration having two loading portions is widely adopted. In this case, the image recording apparatus is provided with two sheets for taking out recording sheets from the two magazines.

[0003] Each of these sheets is provided with a suction disk for sucking a recording sheet, and these suction disks are connected to one vacuum pump. In addition, between these suction disks and the vacuum pump,
An electromagnetic valve is interposed as a switching valve.

[0004]

However, in the above-described image recording apparatus, since two solenoid valves are provided between the two suction plates and the vacuum pump, the manufacturing cost is increased and the apparatus is not easily operated. There has been an inconvenience of increasing the size.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned disadvantages, and has as its object to provide a sheet feeding apparatus capable of reducing the manufacturing cost and reducing the size of the apparatus.

[0006]

According to the present invention, there is provided a sheet feeding apparatus comprising:
And second sheet storage means, first and second suction means for taking out the recording medium from the first and second sheet storage means, respectively, and the first and second suction means. , Each having a three-way valve connected via first and second pipes, and a negative pressure supply source connected via the three-way valve and a third pipe. The invention according to claim 1).

[0007] In a state where the recording medium is adsorbed to only one of the first adsorbing means and the second adsorbing means, the three-way valve is switched to switch the first and second pipes. And the third tube are alternately communicated to gradually increase the pressure of the first tube or the second tube, and the first suction means or the second suction means The recording medium adsorbed on the recording medium is released (the invention according to claim 2).

As described above, by forming the sheet feeding apparatus using one three-way valve for two suction means, it is possible to reduce the manufacturing cost and reduce the size of the apparatus.

[0009] The three-way valve is constituted by an electromagnetic valve (the invention according to claim 3).

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With respect to a sheet feeding apparatus according to the present invention, an image recording apparatus to which the sheet feeding apparatus is applied will be described as a preferred embodiment, and will be described in detail below with reference to the accompanying drawings.

[0011] In the image recording apparatus of the present embodiment,
A dry system is employed in which an image recording medium on which a latent image is formed by irradiating a laser beam is developed (developed) into the latent image by using a dry developing method without using a processing liquid. .

The dry developing method includes the following (1) to
It is possible to adopt the method (4).

(1) A method of transferring a latent image onto an image receiving material by superposing the photosensitive material on which the latent image has been formed on the image receiving material and heating (pressing simultaneously, if necessary) (for example, Japanese Patent Laid-Open No. JP-A-5-113629, JP-A 8-
No. 62803, JP-A-9-152705, JP-A-9-258404, JP-A-9-61978, JP-A-10-71740, Japanese Patent Application No. 10-9
0181, Japanese Patent Application No. 10-13326, and Japanese Patent Application No. 10-18172).

(2) A system in which a latent image is visualized by superposing a photosensitive material on which a latent image is formed with a processing material and heating the same (for example, Japanese Patent Application Laid-Open No. 9-274295, Japanese Patent Application No. 10-1998) No. 17192).

(3) After forming a latent image on a photosensitive material having a photosensitive layer in which silver halide acting as a photocatalyst, silver salt acting as an image forming substance, a reducing agent for silver ions, and the like are dispersed in a binder, A method of visualizing a latent image by heating this photosensitive material to a predetermined temperature {for example,
"The heat-processed silver system (Thermally Proces
sed Silver Systems) "[B. By Shely,
Imaging Processes and Materials Neblette 8
Plate, Sturge, V.E. Walwor
th), A. Edited by Shepp, page 2, 1996
Year], Research Disclosure 17029 (1978
Year), EP803764A1, EP803765A1
No., JP-A-8-212521.

(4) Photosensitivity comprising a thermoresponsive microcapsule containing a colorless electron-donating dye, a compound having an electron acceptor and a polymerizable vinyl monomer in the same molecule, and a photopolymerization initiator. A method using a light- and heat-sensitive recording material provided with a heat-sensitive recording layer (see, for example, JP-A-4-249251), or a heat-responsive microcapsule containing a colorless electron-donating dye, an electron-accepting compound, A method using a light and heat sensitive recording material provided with a light and heat sensitive recording layer containing a polymerizable vinyl monomer and a photopolymerization initiator (see, for example, JP-A-4-21252).

In the methods (1) and (2), a small amount of water may be added to the photosensitive material in order to promote the visualization of the latent image formed on the photosensitive material.

In the present embodiment, the above (1) to (1)
The light-sensitive material and the light- and heat-sensitive recording material used in the method (4) are collectively referred to as a heat-developable light-sensitive material.

FIG. 1 is a perspective view showing an image recording apparatus 10 to which an embodiment of the present invention is applied.

In the upper left portion of the front (operation surface) of the apparatus main body 12 of the image recording apparatus 10, a touch panel 14 having an operation section for operating the image recording apparatus 10 and a monitor function is provided. A door 16 is provided below the touch panel 14 on the front of the apparatus main body 12. By opening the door 16, a sheet supply unit 22, which will be described later, which is disposed inside the apparatus main body 12,
Maintenance can be performed on the front transport unit 24, the image recording unit 26, the transfer unit 28, the heat development unit 30, and the discharge unit 34.

FIG. 2 is an explanatory diagram showing a schematic configuration of the image recording apparatus 10.

The image recording apparatus 10 includes a sheet supply unit 22, a pre-conveyance unit 24, an image recording unit 26, and a transfer unit provided in the order of the conveyance path of a recording sheet 20 as an image recording medium made of a photothermographic material. 28, a thermal developing unit 30, and a discharging unit 34. The image recording apparatus 10 includes a sheet supply unit 22, a front conveyance unit 24, an image recording unit 26, a transfer unit 28, a heat development unit 30, and a discharge unit 3.
4 has a control unit 36 for controlling the operation.

A chamber 42 is formed at a substantially central portion inside the apparatus main body 12 using light shielding plates 40a to 40c.
The sheet supply unit 22 is provided in the chamber 42. The chamber 42 is divided into an upper chamber 42a and a lower chamber 42b by a light shielding plate 40b.
The lower chamber 42b is provided with a lower loading portion 44b and a lower sheet portion 46b.

A magazine (first sheet accommodating means) 48a and a magazine (second sheet accommodating means) 48b are provided in the upper loading section 44a and the lower loading section 44b, respectively.
These magazines 48a, 4
A plurality of recording sheets 20 are stored in each of the recording sheets 8b.

Usually, the recording sheets 20 of different sizes are stored in the magazines 48a and 48b, respectively. For example, the magazine 48a has an H-cut (half-cut) size (3
The recording sheet 20 of 5.4 cm × 43.0 cm) or B4 size is accommodated, and the magazine 48 b accommodates the recording sheet 20 of 6 pieces (20.3 cm × 25.4 cm).

As shown in FIG. 1, the door 16 provided on the front of the apparatus main body 12 has magazine mounting holes 50a, 50b.
Are formed, and these magazine mounting holes 50a, 50
The magazines 48a and 48b are attached to and detached from the upper loading section 44a and the lower loading section 44b via the b.

On the front side of the magazines 48a and 48b, shutter insertion holes 52a and 52b are formed, respectively. Through these shutter insertion holes 52a and 52b, light-shielding shutters 54a and 54b shown in FIG. Are mounted on the upper surfaces of the magazines 48a and 48b, respectively. As described above, the magazines 48a and 48b are provided with the shutters 54a and 5b.
When the door 16 is opened, the recording sheet 20 stored in the magazines 48a and 48b is prevented from being exposed when the door 16 is opened.

The upper sheet portion 46a and the lower sheet portion 46b provided at the upper right portion of the upper chamber 42a and the lower chamber 42b respectively have an adsorber (the first disc) which can freely enter the magazines 48a and 48b. (A suction means) 60a and a suction board (a second suction means) 60b. Suction cup 60
Displacement means (not shown) for displacing the suction disks 60a, 60b are connected to the suction plates 60a, 60b.

As shown in FIG. 3, the suction disks 60a, 60b
Are connected to a three-port solenoid valve (three-way valve) 74 via a pipe (first pipe) 70 and a pipe (second pipe) 72, respectively. Further, a vacuum pump (negative pressure supply source) 78 is connected to the electromagnetic valve 74 via a tube (third tube) 76. In this case, the pipe 70 has
A of the solenoid valve 74 communicating with the tube 76 in the FF state.
The pipe 72 is connected to a port 74a, while the pipe 72 is connected to a B port 74b of the solenoid valve 74 which communicates with the pipe 76 when the solenoid valve 74 is in the ON state. A pressure gauge 80 for detecting the pressure inside the pipe 76 is connected to the pipe 76.

As described above, these suction disks 60a, 60
b, the pipes 70 and 72, the electromagnetic valve 74, the pipe 76, the vacuum pump 78 and the pressure gauge 80 constitute a suction mechanism for the recording sheet 20 in the sheet supply unit 22.

As shown in FIG. 2, a roller pair 90 is disposed downstream of the suction plate 60a in the upper sheet leaf portion 46a, and a roller pair 92 is disposed downstream of the roller pair 90. . A passage hole 94 communicating with the lower chamber 42b is formed near the downstream side of the roller pair 92 in the light shielding plate 40b.

The light shielding plate 40c is formed with a passage hole 98 communicating with the outside of the lower chamber 42b. In FIG. 2, guide plates 102a and 102b provided so as to extend from the vicinity of the right side of the passage hole 94 of the light shielding plate 40b to the vicinity of the right side of the passage hole 98 of the light shielding plate 40c.
The recording sheet 20 is formed by guide plates 104a and 104b provided so as to extend from near the left side of the passage hole 94 at 0b to near the left side of the passage hole 98 at the light shielding plate 40c.
Are formed so as to form a bulged space.

The guide plates 102a and 102b are directly connected, and the guide plates 104a and 104b are
6 are provided continuously. That is, the roller pair 106
Is arranged downstream of the suction plate 60b in the lower sheet portion 46b.

In this case, the roller pair 92 is configured as a light blocking roller for preventing light from entering the upper chamber 42a through the passage hole 94. The roller pair 106
The guide plate 10 passes through the passage hole 94 or the passage hole 98.
The light that has entered the expanded space formed by the guide plates 104a and 104b and the guide plates 104a and 104b further
The lower chamber 42b is configured as a light blocking roller that prevents the lower chamber 42b from entering the lower loading portion 44b.

On the downstream side of the sheet supply unit 22, that is, at the lower right part inside the apparatus main body 12, the front transport unit 24 is provided.
Is provided. The front transport unit 24 includes a roller pair 130 disposed near the passage hole 98 and a roller pair 130.
The roller pair 132 disposed downstream of the roller pair 130, and a width-shifting claw 134 disposed between the roller pairs 130 and 132. A displacement mechanism 136 for displacing the width shifting claw 134 in the width direction of the recording sheet 20 is provided on the width shifting claw 134.
Are connected. Further, a plate 138 is arranged in the front conveyance section 24 along the conveyance path of the recording sheet 20.

In the vicinity of the roller pair 132 on the downstream side of the roller pair 132, a correction roller 194 for correcting the transport direction of the recording sheet 20 is disposed. The correction roller 194 is rotatable about an axis in a plane orthogonal to the recording sheet 20, and is fixed using a fixing unit (not shown) so that the axis has a predetermined inclination angle. In this case, the inclination angle of the correction roller 194 is set to an angle such that the conveyance direction of the recording sheet 20 after passing through the correction roller 194 is corrected in a predetermined direction.

An image recording section 26 for forming a latent image on the recording sheet 20 is provided on the downstream side of the front transport section 24, that is, on the lower left portion inside the apparatus main body 12. The image recording unit 26 includes a first roller pair 200 and a second roller pair 202 that are driven to rotate in synchronization with each other.
202 is openable and closable. In this case, the first and second roller pairs 200 and 202 form a sub-scanning mechanism 204 that conveys the recording sheet 20 in the sub-scanning direction (the direction of arrow A in FIG. 2).

First and second roller pairs 200 and 202
Between them, a guide plate 206 and a pressing roller 208 for pressing the recording sheet 20 against the guide plate 206 are arranged. The pressing roller 208 is configured to be vertically displaceable so as to press the recording sheet 20 by its own weight. Such a pressing roller 2
By providing 08, it is possible to prevent the recording sheet 20 from becoming loose or the like.

Above the sub-scanning mechanism 204, an optical system 210 for irradiating the recording sheet 20 conveyed in the sub-scanning direction with a laser beam L in the main scanning direction (a direction substantially orthogonal to the sub-scanning direction). Is provided. In this case, the optical system 2
10, the second roller pair 202 and the pressing roller 20
8 is irradiated with the laser light L.

The optical system 210 has a wavelength of 66 as a light source.
It has two semiconductor lasers of 0 nm and an output of 30 mW. The laser lights output from these semiconductor lasers are multiplexed and further deflected by a rotary polygon mirror, and then converted as laser light L via an fθ lens. Scanning is performed on the recording sheet 20. In this case, the beam diameter of the laser light L is set to 100 μm, and the pitch in the sub-scanning direction is 25 μm.
Is set to Then, the laser light L is applied four times,
Scanning is performed on the recording sheet 20 based on the same image information. That is, an image (latent image) having a width of one pixel is formed on the recording sheet 20 by scanning the laser light L four times in the main scanning direction while shifting the position in the sub-scanning direction by 25 μm.

On the back side of the recording sheet 20 viewed from the optical system 210, a sensor 212 for detecting the position of the leading end of the recording sheet 20 is provided. A lens 214 for correcting a shift in the irradiation direction of the laser light L is disposed above the sensor 212 along the irradiation direction of the laser light L.

A transfer section 28 is provided on the downstream side of the image recording section 26, that is, on the left side inside the apparatus main body 12. The transfer unit 28 is provided near the downstream side of the second roller pair 202 in the image recording unit 26.
A pair of guide plates 220a and 220b are provided. Of the guide plates 220a and 220b, the guide plate 220a disposed outside is openable and closable about the rotation shaft 220c as a fulcrum. Therefore, even when the recording sheet 20 is jammed between the guide plates 220a and 220b, the recording sheet 2
0 can be easily taken out.

A roller pair 221 is disposed downstream of the guide plates 220a and 220b, and a pair of guide plates 222a and 222b is disposed further downstream. Of the guide plates 222a and 222b, the guide plate 222a disposed outside is freely openable and closable about the rotation shaft 222c as a fulcrum. For this reason, the guide plates 222a, 22
Even when the recording sheet 20 is jammed during 2b, the recording sheet 20 can be easily taken out.

Two pairs of rollers 223 and 224 are arranged downstream of the guide plates 222a and 222b. A one-way clutch (not shown) for restricting rotation of the roller pairs 223 and 224 is connected to a rotation shaft (not shown) of the roller pairs 223 and 224. Roller pair 2
A cleaning roller 225 is disposed downstream of the cleaning roller 24.

On the downstream side of the transfer section 28, that is, on the upper left portion inside the apparatus main body 12, heat for developing the latent image on the recording sheet on which the latent image is formed (thermal development) is used. A developing unit 30 is provided. This heat developing section 30
Are four plate heaters 230 arranged on the same circumference.
a to 230d. These plate heaters 23
The inner surfaces 232a to 232d of Oa to 230d are formed in a substantially circular arc shape in cross section, and the conveying path of the recording sheet 20 is configured to be circumferential along the inner surfaces 232a to 232d.

Three pressing rollers 234 are in contact with the inner surfaces 232a to 232d of the plate heaters 230a to 230d, respectively. Also, the plate heater 230
A pair of rollers 236 is arranged near the upstream side of a, and a pair of rollers 238 is arranged near the downstream side of the plate heater 230d. Further, a roller pair 240 is disposed downstream of the roller pair 238.

A sensor unit 242 for measuring the density of an image recorded on the recording sheet 20 is disposed at a position spaced a predetermined distance downstream from the roller pair 240.
The sensor unit 242 includes a light emitting element 242a and a light receiving element 242b. Further, the sensor unit 242 is connected to a displacement mechanism (not shown), and it is possible to change an arrangement position of the recording sheet 20 along the conveyance path by the displacement mechanism. In this case, the position of the sensor unit 242 can be adjusted so that the density of the image is measured after the recording sheet 20 is sufficiently cooled.

An exhaust fan 243 is provided in the heat developing section 30.
Is arranged. A fan is not provided in an area where the sheet supply unit 22, the front conveyance unit 24, the image recording unit 26, and the transfer unit 28 are arranged. For this reason,
Generation of dust and the like is avoided.

Further, a heat insulating material 244 is provided on the inner wall surface of the apparatus main body 12 so as to surround the heat developing section 30.
By providing the heat insulating material 244 in this manner, heat from the plate heaters 230a to 230d can
Is not transmitted to the recording sheet 20 discharged onto the discharge tray 292.

A discharge section 34 is provided on the downstream side of the heat development section 30, that is, on the upper right portion inside the apparatus main body 12.

The discharge section 34 has a pair of rollers 250 and a movable guide plate 252 disposed downstream of the pair of rollers 250 for switching the transport path. The movable guide plate 252 is connected to a drive device (not shown) such as a solenoid, and is driven to rotate within a predetermined range around the rotation shaft 253 by the drive device.

On the downstream side of the movable guide plate 252, a first guide plate 254 constituting one transport path (lower transport path) of the recording sheet 20 and the other transport path (upper transport path) of the recording sheet 20 are provided. A second guide plate 256 that constitutes a (conveyance path) is disposed.

A roller pair 260 is disposed at a position downstream of the first guide plate 254 and close to a first discharge port 258 formed on the right side wall of the apparatus main body 12. Hereinafter, the direction from the roller pair 260 to the later-described first discharge tray 290 via the first discharge port 258 is referred to as a first discharge direction a.

The second guide plate 256 is formed in a curved shape, and its downstream end is located in a protruding portion 262 formed in the upper right corner of the apparatus main body 12. At a position on the downstream side of the second guide plate 256 and close to a second discharge port 266 formed on the left side wall of the protrusion 262,
A roller pair 268 is provided. Hereinafter, the roller pair 268
From the second discharge tray 292 through the second discharge port 266.
Is referred to as a second discharge direction b.

As shown in FIG. 1 and FIG.
The recording sheet 2 discharged from the first discharge port 258 is located at a position below the first discharge port 258 on the right side wall of the recording sheet 2.
A first discharge tray 290 that accommodates 0 is attached. Further, a second discharge tray 292 is formed integrally with the apparatus main body 12 on the upper surface of the apparatus main body 12 on the downstream side of the second discharge port 266.

As shown in FIG. 2, a control section 36 is provided at the bottom inside the apparatus main body 12. This control unit 3
6 includes a control device 310 and a power supply device 312. In addition, the control unit 36 supplies the power supply device 312 with:
A cooling fan 314 is provided.

The image recording apparatus 10 according to the present embodiment
Basically, it is configured as above,
The operation and effect will be described.

First, the magazines 48a and 48b containing the recording sheets 20 are mounted on the upper loading section 44a and the lower loading section 44b, respectively (see FIG. 2). Then, based on the instruction to the touch panel 14, the magazine 48
The recording sheet 20 is taken out from either one of the recording sheets 20a and 48b.

Magazine 48 mounted on upper loading section 44a
In a, by driving a displacement means (not shown) connected to the suction disk 60a, the suction disk 60a enters the magazine 48a. At this time, as shown in FIG. 3, by turning off the electromagnetic valve 74, the suction plate 60a is communicated with the vacuum pump 78, and the suction plate 60a
The recording sheet 20 is sucked.

Then, the recording sheet 20 is supplied to the roller pair 90 by driving the displacement means.

At this time, the recording sheet 20 adsorbed on the suction disk 60a is stopped by stopping the vacuum pump 78 and turning on / off the electromagnetic valve 74 a plurality of times (for example, five times). To be released.

More specifically, as shown in FIGS. 3 and 4, the recording sheet 20 is adsorbed on the suction disk 60a.
When the solenoid valve 74 is switched from OFF to ON at time t0 when the pressure P in the pipe 70 is P = P0, the pressure P in the pipe 70 is maintained at P = P0, Reference numeral 76 denotes a suction disk 60 on which the recording sheet 20 is not suctioned.
As a result, the pressure P 'in the tube 76 becomes the atmospheric pressure (P' = 0). Next, the solenoid valve 74 is turned ON from ON.
When the mode is switched to FF (time t1), the inside of the pipe 70 and the pipe 7
6, the pressure P in the pipe 70 rises to P = P1.

Similarly, at times t2 to t9, by repeatedly turning ON / OFF the solenoid valve 74, the pressure P in the pipe 70 gradually increases to P2 to P4, and finally P = 0. And the recording sheet 20 is released from the suction disk 60a.

The number of ON / OFF operations of the solenoid valve 74 required until the recording sheet 20 is released from the suction disk 60a depends on the volume ratio between the tube 70 and the tube 76.

The recording sheet 20 is conveyed by a pair of rollers 90 and is supplied to a pair of rollers 92. Further, the recording sheet 20 is conveyed by the roller pair 92,
Through the guide plates 102a, 10a in the lower chamber 42b.
2b and the guide plates 104a and 104b.

On the other hand, in the magazine 48b mounted on the lower loading section 44b, by driving a displacement means (not shown) connected to the suction disk 60b,
b enters the magazine 48b and sucks the recording sheet 20. Then, the recording sheet 20 is supplied to the roller pair 106 by driving the displacement unit, and is sent downward between the guide plates 102a and 102b and the guide plates 104a and 104b by the roller pair 106.

In this case, for the suction disk 60b, the reverse processing (the electromagnetic valve 74) is performed for the suction disk 60a.
(Switching process in which ON and OFF are reversed), the recording sheet 20 is attracted and released.

Guide plates 102a, 102b and guide plate 1
04a, 104b, the recording sheet 20 sent between
The toner is supplied to the roller pair 130 constituting the front transport unit 24 through the passage hole 98.

The recording sheet 20 is sent to the roller pair 132 by the roller pair 130, and at that time, the position in the width direction is adjusted by the width shifting claw 134 disposed between the roller pairs 130 and 132.

The recording sheet 20 has a pair of rollers 132
When the paper passes through the correction roller 194 provided on the downstream side of the printer, the transport direction is corrected in a predetermined direction according to the inclination angle of the correction roller 194. And the correction roller 19
The recording sheet 20 that has passed through 4 is supplied to a first roller pair 200 that forms the sub-scanning mechanism 204 of the image recording unit 26.

The recording sheet 20 supplied to the first roller pair 200 is further sent to the second roller pair 202,
The first and second roller pairs 200 and 202, which are driven in synchronization with each other, rotate in the sub-scanning direction (FIG. 2).
(In the direction of arrow A). At this time, the recording sheet 20 is pressed against the guide plate 206 by the pressing roller 208.

When the recording sheet 20 is conveyed in the sub-scanning direction by the first and second roller pairs 200 and 202, the laser light L from the optical system 210 emits the recording sheet 20.
Is irradiated in the main scanning direction to form a latent image on the recording sheet 20. At this time, the position of the leading end of the recording sheet 20 is confirmed by the sensor 212 that detects the laser light L from the optical system 210 via the lens 214.

The recording sheet 20 on which the latent image has been formed in the image recording section 26 is conveyed by the second pair of rollers 202, and guide plates 220a and 220 constituting the transfer section 28.
The roller is sent to the roller pair 221 via b. Further, the recording sheet 20 is conveyed by a roller pair 221 and passes through guide plates 222a and 222b to form two roller pairs 223 and 22.
4 sequentially.

A one-way clutch is connected to a rotating shaft (not shown) of the pair of rollers 223 and 224, and the rotation of the pair of rollers 223 and 224 is regulated by the one-way clutch.

The recording sheet 20 that has passed through the pair of rollers 223 and 224 is sent to the heat developing unit 30 after dust and the like are removed by the cleaning roller 225.

The recording sheet 20 is sequentially supplied to the plate heaters 230a to 230d by the roller pair 236. At this time, the recording sheet 20 is
Is pressed down by the plate heaters 230a to 230d, and is thermally developed by the heat from the plate heaters 230a to 230d. Then, the recording sheet 20 after the heat development is conveyed to the downstream side via the roller pairs 238 and 240.

In this case, the conveying speed of the recording sheet 20 by the pressing roller 234 is adjusted to be higher than the conveying speed by the pair of rollers 223 and 224. This is because the recording sheet 20 has a plate heater 230a.
This is for avoiding being pushed between the pressing roller 234 and the holding roller 234. The roller pair 223, 2
A one-way clutch (not shown) is connected to the recording sheet 24 and the recording sheet 20 from the pair of rollers 223 and 224 to the heat developing unit 30 is operated by the operation of the one-way clutch.
Delivery is carried out smoothly.

A sensor unit 242 is provided downstream of the roller pair 240. The light emitting element 242a and the light receiving element 242b constituting the sensor unit 242 measure the density of the image recorded on the recording sheet 20. You. Then, the recording sheet 2 that has passed through the sensor unit 242
“0” is sent to the discharge unit 34.

While the recording sheet 20 supplied to the roller pair 250 of the discharge section 34 is conveyed by the roller pair 250, the conveyance path is switched by a movable guide plate 252 provided downstream thereof. When the movable guide plate 252 is shifted downward, the recording sheet 20 is in the first position.
When the movable guide plate 252 is shifted upward, the recording sheet 20 is sent to the upper transport path along the second guide plate 256. Can be

The recording sheet 20 sent to the lower conveying path
Is supplied to the roller pair 260 via the first guide plate 254, and the first discharge port 258 is supplied by the roller pair 260.
Sent to Then, the first discharge port 258
Are discharged along the discharge direction a of the first discharge port 258.
Is stored in a first discharge tray 290 provided below the printer.

On the other hand, the recording sheet 20 sent to the upper conveyance path is moved along a second guide plate 256 by a pair of rollers 268.
Supplied to Then, the sheet is sent to the second discharge port 266 by the roller pair 268, and is discharged onto the second discharge tray 292 from the second discharge port 266 in the second discharge direction b.

As described above, in the present embodiment, the two suction plates 60a and 60b
One solenoid valve 74 of a three-way switching type (3 ports)
Is connected to the vacuum pump 78 via the. For this reason,
It is possible to reduce the manufacturing cost and reduce the size of the image recording apparatus 10 to which the sheet supply unit 22 is applied.

[0083]

In the sheet feeding apparatus according to the present invention, the first and second sheets for taking out the recording medium from the first and second sheet accommodating means respectively accommodating the sheet-shaped recording medium are provided. Is connected to a negative pressure supply via one three-way valve. Therefore, it is possible to reduce the manufacturing cost of the sheet feeding device and to reduce the size of the device.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an image recording apparatus to which an embodiment of the present invention has been applied.

FIG. 2 is an explanatory longitudinal sectional view schematically showing the configuration of the image recording apparatus shown in FIG.

FIG. 3 is a circuit diagram schematically illustrating a suction mechanism in a sheet supply unit included in the image recording apparatus illustrated in FIG. 2;

FIG. 4 is an explanatory view showing a process for releasing a recording sheet sucked by a suction disk in the suction mechanism shown in FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Image recording apparatus 20 ... Recording sheet 22 ... Sheet supply part 48a, 48b ... Magazine 60a, 60b ... Suction board 70, 72, 76 ... Tube 74 ... Electromagnetic valve 78 ... Vacuum pump

Claims (3)

[Claims] A first sheet accommodating means for accommodating a sheet-shaped recording medium, and a first sheet accommodating means for accommodating the sheet-shaped recording medium.
First and second suction means for removing the recording medium, the first and second suction means, a three-way valve connected via first and second pipes, respectively, A sheet supply device, comprising: a valve and a negative pressure supply connected via a third tube. 2. The apparatus according to claim 1, wherein the three-way valve is switched by switching the three-way valve in a state where the recording medium is attracted only to one of the first attracting means and the second attracting means. By alternately connecting the first and second tubes and the third tube, the pressure of the first tube or the second tube is gradually increased, and the first adsorption is performed. A sheet feeding device for releasing the recording medium sucked by the first suction means or the second suction means. 3. The sheet feeding device according to claim 1, wherein the three-way valve is constituted by a solenoid valve.