JP2901334B2 - Manual paper feeder - Google Patents

Description

The present invention relates to a manual paper feeder used in, for example, a laser printer, a facsimile machine, a PPC copier, and the like.
In particular, the present invention relates to a manual sheet feeding device capable of improving initial sheet feeding performance in manual sheet feeding.

[Conventional technology]

Conventionally, in an image forming apparatus such as a laser printer,
In addition to an automatic paper feeder using a paper feed cassette or the like, a manual paper feeder that feeds a single sheet material (paper) is often used. This manual paper feeder is provided, for example, to cope with diversifying paper sizes or types.

Various configurations of this type of conventional manual paper feeder have been proposed, such as a configuration using an upper surface portion of an automatic paper feed cassette and a configuration in which a manual paper feeder is separately provided.

By the way, recent image forming apparatuses have been miniaturized, and the number of sheet cassettes in automatic sheet feeding apparatuses that are completely housed in the main body of the image forming apparatus has increased. For this reason, the manual paper feeder using the upper surface of the paper cassette is
There is a decreasing trend.

Further, as the size of the main body of the image forming apparatus is reduced, the size of the manual sheet feeder is naturally required. For this reason, the paper mounting area (paper feed tray) of the manual paper feeder tends to be reduced. Further, according to a recent manual paper feeder, a paper feed tray having only a manual paper feed opening opening in the outer cover of the apparatus without a paper feed tray has appeared.

[Problems to be solved by the invention]

However, in such a conventional manual paper feeder, it is becoming impossible to cope with all paper sizes due to the reduction of the paper mounting area. That is, in the manual paper feeder having the above configuration, for example, the rear end of the paper of B4 or A3 size hangs outside the manual paper feeder, and the moment the hand is released, the paper drops due to its own weight. was there.

[Object of the invention]

Therefore, according to the present invention, by rotating the pair of conveying rollers for a short time before the regular conveyance, the leading end of the sheet material inserted from the manual sheet feeding port is sandwiched between the nip portions of the pair of conveying rollers, and the sheet material is dropped. The purpose of the present invention is to realize reliable sheet feeding and conveyance by preventing the occurrence of a sheet.

Further, in the present invention, in the rising rotation region before the drive motor reaches a certain rotation speed, the short-time rotation operation of the conveyance roller pair in the previous conveyance performs the leading end portion of the sheet material in the nip of the conveyance roller pair. The purpose of the operation is to make the operation of the pinching gentle.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a manual paper feed port through which a sheet material is fed, and a conveying roller pair disposed at a position where the leading end of the sheet material inserted from the manual paper feed port abuts. A manual feeder having a sensor provided just before the pair of conveying rollers for detecting the front end of the sheet material, and a drive motor for driving the pair of conveying rollers, wherein the front end of the manually fed sheet material is And before the start of the sheet conveyance by the conveyance roller pair, the conveyance before rotating the conveyance roller pair for a predetermined short time so that the leading end portion of the sheet material is sandwiched between the nip portions of the conveyance roller pair. A control means is provided for performing a pre-conveying operation by short-time rotation of the conveying roller pair so that the drive motor reaches a constant rotational speed after a predetermined time has elapsed from the detection of the leading edge of the sheet material by the sensor. It is characterized in that performed at the rising rotation region before that.

 Hereinafter, the present invention will be described based on examples.

 1 to 5 are views showing one embodiment of the present invention.

 First, the configuration will be described.

FIG. 3 is an overall internal configuration diagram of a laser printer to which the manual sheet feeder according to the present invention is applied. In the figure,
Reference numeral 10 denotes a printer main body divided into an upper unit 10a and a lower unit 10b. The upper unit 10a is supported rotatably about the pin 11 with respect to the lower unit 10b. Reference numeral 12 denotes a paper feed cassette detachably attached to a lower portion of the printer main body 10. The paper 14 fed from the paper feed cassette 12 by the paper feed roller 13 is transported by the transport roller pair in the present invention.
The sheet is conveyed to the lower side of the belt-shaped photoconductor 16 at a predetermined timing by a pair of registration rollers 15 via 101.

The photoreceptor 16 is driven to rotate in the direction of the arrow, and the surface of the photoreceptor 16 is uniformly charged by a charger 17, and an electrostatic latent image is formed on the photoreceptor 16 based on an optical signal from the optical unit 18. Is done. This latent image is visualized by toner in the developing device 19, and this visible image is transferred by the transfer charger 20 onto the conveyed paper 14.

The sheet 14 is conveyed to a heat fixing device 21 and a visible image is fixed thereon. Then, the paper 14 exiting the heat fixing device 21 is switched immediately after passing between the lower paper discharge roller pair 23 of the paper discharge device 22.
24 allows the paper ejection direction to be switched up and down. And
When it is switched upward, it is guided by the paper discharge guides 25 and 26, and the upper surface paper discharge roller 27 and the pinch roller 28 from the upper paper discharge port 29 to the stack unit 30 on the upper surface of the upper unit 10a with the image side down. Is discharged. When the sheet 14 is switched downward, the sheet 14 is discharged rearward from the lower discharge port 31 by the lower discharge roller 23 with the image surface facing upward.

On the other hand, the photosensitive member 16 after the transfer of the visible image is
The residual toner is removed by 32, and the charge is further reduced by the light from the charge reduction device 33 to prepare for the next image forming cycle.

An air intake fan 34 is arranged below the transfer charger 20, and an air intake port 35 provided at the bottom of the lower unit 10b.
After cooling the power supply unit 36 with air taken in from the printer, the power supply unit 36 is blown around the transfer charger 20 to discharge ozone outside the apparatus.

FIG. 4 is a schematic view of the inside with the upper unit 10a opened, and FIG. 5 is a perspective view of the appearance. The photoconductor 16 and the cleaning device 32 are unitized to form the upper unit 10a.
It can be attached to and detached from. Optical unit 18,
The charging device 33 and the charging charger 17 are also provided in the upper unit 10a.
Attached to the side.

On the other hand, an operation panel 38 is provided on the upper cover 37 on the lower unit 10b side, and a front door 39 is attached to the lower side so as to be openable and closable. The front door 39 is provided with a paper feed port 40 for a manual feed tray and an optional paper feed tray.
A paper feed guide 41 for guiding the paper 14 fed by the paper feed roller 13 is provided on the inner surface of the paper feed roller 13. Developing device 19 is a front door
Open 39 and replace. In FIG. 5, reference numeral 42 denotes a controller, and 43 denotes a card insertion slot for inserting an IC card.

FIG. 1 is a schematic diagram showing the configuration of a manual paper feeder according to the present invention applied to the laser printer.

In the figure, reference numeral 101 denotes a pair of transport rollers (a pair of grip rollers), which is disposed at a position where the leading end of the paper 14 inserted from the paper feed port 40 abuts, and the paper 14 is synchronized with the operation of the laser printer. Carry inside the printer. Reference numeral 102 denotes a sensor provided immediately before the conveying roller pair 101, and detects a leading end of the sheet 14 inserted from the sheet feeding port 40. Reference numeral 103 denotes, for example, a pre-transport control means provided in the controller 42 shown in FIG. 5, for example, for one second after the detection of the leading end of the sheet 14 by the sensor 102, and for rotating the transport roller pair 101 for 0.2 seconds, for example.

Reference numeral 104 denotes a DC motor serving as a main drive motor, which rotationally drives the transport roller pair 101 in a direction indicated by an arrow in FIG. In the present invention, the short-time rotation operation of the transport roller pair 101 in the previous transport is performed in a rising rotation region before the DC motor 104 reaches a certain rotation speed.

Next, the operation will be described with reference to FIG. 1 and FIG.

FIG. 2 is a timing chart showing the operation of the DC motor 104 in the manual sheet feeder according to the present invention.

First, the paper 14 inserted manually from the paper feed port 40
When the tip of the sensor passes the sensor installation position, the sensor 102
N Then, the leading end of the sheet 14 is inserted until it comes into contact with the nip of the conveying roller pair 101.

One second after receiving the ON signal of the sensor 102, the pre-transport control means 103 sends a drive command to the DC motor 104 to rotate the pair of transport rollers 101. This drive command is
As is apparent from the figure, the sheet is sent at the timing when the pair of conveying rollers 101 is rotated for 0.2 seconds. The drive command is controlled so that the rotation speed of the DC motor 104 falls within a rising rotation region that is lower than a certain rotation speed v in the printing operation.

Thus, in the present embodiment, the conveying roller pair 101
Is rotated for 0.2 seconds and pre-conveyed before regular conveyance, whereby the leading end portion of the paper 14 is sandwiched between the nips of the conveyance roller pair 101 and fixed. As a result, even if the paper that hangs long outside the apparatus is manually fed, the paper does not drop.

In addition, in the rising rotation area before the DC motor reaches a certain rotation speed, by performing a short-time rotation operation of the conveyance roller pair 101 in the previous conveyance, when the leading end portion of the sheet material is pinched in the nip of the conveyance roller pair 101. Can be moderated.

Then, in response to the print start signal from the controller 42 shown in FIG. 5, the printer starts the printing operation in the above-described process.

FIG. 6 is a schematic configuration diagram showing another embodiment of a laser printer to which the manual paper feeder according to the present invention is applied.

In the figure, reference numeral 201 denotes a manual paper feed tray, which rotates around a shaft 202. When manual paper feed is not performed, the manual paper feed tray is integrally stored on the side surface of the upper cover 37. The state shown in the figure shows the state of manual feed use. In this state, the manual paper feed tray 201 inserts paper toward the paper feed port 40. Reference numeral 203 denotes an optional postcard feeder, which inserts a postcard toward the paper feed port 40 similarly to the manual paper feed tray 201.

As is clear from the present embodiment, the manual paper feeder according to the present invention is applicable to image forming apparatuses such as laser printers, facsimile machines, and PPC copiers, regardless of the presence or absence of the manual paper feed tray 201. is there.

Note that the configuration and operation of this embodiment are the same as those of the above-described embodiment, and a description thereof will be omitted.

In the above-described embodiment, the time from the detection of the leading edge of the sheet material to the previous conveyance is 1 second, and the time for the previous conveyance is
Although exemplified as 0.2 seconds, the present invention is not limited to these numerical values, and appropriately sets an optimal value according to the transport distance on the apparatus configuration or the rising rotation area characteristic of the main drive motor. .

〔effect〕

According to the present invention, by rotating the conveying roller pair for a short time before the regular conveying, the leading end portion of the sheet material inserted from the manual paper feed port is sandwiched in the nip of the conveying roller pair, and the falling of the sheet material is prevented. As a result, the sheet can be reliably fed and conveyed.

In addition, in the rising rotation area before the DC motor reaches a certain rotation speed, by performing a short-time rotation operation of the conveyance roller pair in the previous conveyance, the operation when the leading end portion of the sheet material is pinched in the nip of the conveyance roller pair. Can be moderated.

[Brief description of the drawings]

1 to 5 are diagrams showing an embodiment of a manual paper feeder according to the present invention, FIG. 1 is a schematic diagram showing the outline thereof, and FIG. 2 is a DC motor in the manual paper feeder according to the present invention. FIG. 3 is an overall internal configuration diagram of a laser printer to which the manual paper feeder according to the present invention is applied, and FIG. 4 is an internal view of the laser printer with the upper unit shown in FIG. 3 open. FIG. 5 is an external perspective view of the laser printer shown in FIG. 4, and FIG. 6 is a schematic configuration diagram showing another embodiment of the laser printer to which the manual sheet feeder according to the present invention is applied. 40: paper feed port, 42: controller, 101: transport roller pair, 102: sensor, 103: front transport control means, 104: DC motor.

Claims (1)

(57) [Claims] A sheet feeder through which a sheet material is fed; a pair of conveying rollers disposed at a position where the leading end of the sheet material inserted from the manual sheet feeder comes into contact; and a position immediately before the pair of conveying rollers. A manual feeder having a sensor for detecting the leading edge of the sheet material and a drive motor for driving a pair of transport rollers, wherein when the leading edge of the manually fed sheet material is detected by the sensor, the transport is performed. A pre-conveyance control unit that rotates the conveyance roller pair for a predetermined short time so that the leading end portion of the sheet material is sandwiched between the nip portions of the conveyance roller pair before the start of sheet conveyance by the roller pair; The pre-conveying operation by the pair of short-time rotations is performed after a lapse of a predetermined time from the detection of the leading edge of the sheet material by the sensor, and the rising rotation before the drive motor reaches a certain rotation speed. Manual sheet feeder, which comprises carrying out in-band.