JPH08301487A - Paper feeder in image forming device - Google Patents

Abstract

PURPOSE: To facilitate removal of paper when paper passing through between two sheets of guide plates is jammed and, to simplify a constitution for mounting a sensing means for detecting a contact piece or the like for sensing passing through of paper. CONSTITUTION: A guide plate 19 is turned to separate from an oppositely facing fixed guide plate 18 with a pivotal support shaft 20 serving as the center. A contact piece 28 is secured to a turn shaft 25 supported turnably to a bracket protrusively provided in a reverse surface of the guide plate 19, also to provide a detected member 30 through a supporter 31 in a lower end of an arm 29 secured to the turn shaft 25, and to protrude a tip end of the contact piece 28 from a window hole 26 of the guide plate 19 toward a surface of the fixed guide plate 18. In a condition without paper 5, the detected member 30 in the lower end of the arm 29 is constituted so as to approach a sensor 33 on a base board 32. When a paper jam is generated, when the guide plate 19 is separated from the fixed guide plate 18, also the contact piece 28 is separated, consequently to easily remove paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction of a paper feeding device for feeding paper to an image forming section in an image forming apparatus such as a copying machine, a printer, a facsimile machine or the like.

[0002]

2. Description of the Related Art Conventionally, as an image forming unit in this type of image forming apparatus, there is a print head such as a thermal head or a dot pin, or an electrophotographic image forming unit such as a photosensitive drum. As disclosed in Japanese Patent Laid-Open No. 35244/1993, the sheets stacked and stored in the sheet cassette are rolled one by one by a sheet feeding roller and sent out between two conveying guide plates on the upstream side of the conveying to convey the sheet. A sheet feeding device is known in which a sheet is supplied to the image forming apparatus by a pair of conveying rollers arranged in the middle of the guide plate, and a sheet feeding device is provided between the sheet feeding roller and the image forming section. When a so-called paper jam occurs where paper cannot be fed due to jammed paper, open the upper cover of the image forming apparatus and remove the jammed paper, as disclosed in the above publication. Which was.

[0003]

However, in the image forming apparatus as described above, when the two conveyance guide plates in the paper feed path are fixed, the paper jammed from the narrow gap between the guide plates is removed. It was difficult to remove. In addition, in the paper feed path between the paper feed roller and the image forming unit, an image is formed so that the leading end of the fed paper is sensed and printing (image formation) is performed at a predetermined position of the leading end of the paper. Although a paper detection sensor is provided for adjusting the timing of starting printing in each section, if the two conveyance guide plates in the paper feed path are fixed, the jammed paper may be caught by the paper detection sensor. Becomes more difficult to remove.

Further, when a paper detection sensor is fixedly provided on the conveyance guide plate, the wiring from the paper detection sensor to the control board must be arranged in a hollow portion in the image forming apparatus, and the wiring is swayed. There was a problem that it was easy.
The present invention has been made to solve these conventional technical problems, and it is possible to easily remove a jammed sheet and to easily configure a structure for mounting a sheet sensing unit. An object of the present invention is to provide a sheet feeding device in a forming apparatus.

[0005]

In order to achieve the above object, a sheet feeding device in an image forming apparatus according to a first aspect of the present invention has a sheet feeding path for guiding and feeding a sheet to an image forming section. A sheet feeding device in an image forming apparatus, which comprises two guide plates facing each other on the front and back sides, and one of the guide plates is provided with a sensing means for detecting whether or not a sheet has passed. This guide plate is provided so as to be separable from the other guide plate, and the sensing means is provided on one guide plate.

The invention described in claim 2 is the same as claim 1
In the paper feeding device of the image forming apparatus described in (1) above, a sensing unit rotatably attached to the one guide plate,
A contact piece projecting to the surface side of the other guide plate, and a detected part for sensing the displacement of the fixed sensing part in conjunction with the movement of the contact piece. is there.

Further, in the invention described in claim 3, in the sheet feeding device in the image forming apparatus according to claim 1 or 2, the contact piece and the detected portion in the sensing means are guided to the one side. It is attached so as to rotate integrally with a rotation shaft provided on the back side of the plate.

[0008]

Next, an embodiment of the present invention will be described. FIG. 1 is a schematic side sectional view of a paper feeding device 1 in a facsimile apparatus to which the present invention is applied, and FIG. 2 is a side sectional view of a main part of the paper feeding device 1. Paper feed cassette box 3 placed under the main frame (not shown) of the facsimile machine
The sheets 5 stacked on the receiving tray 4 are wound one by one by a sheet feeding roller 6 which is intermittently rotated above the sheet receiving sheet 4, and includes a line type thermal head 8 and a platen roller 9 through a sheet feeding passage 7. It is sent to the image forming unit 10. This image forming unit 10
Wide sheet-shaped ink sheet 1
A reel 12 wound around 1 and a take-up reel 13 are arranged. The ink sheet 11 passes from the front guide reel 14 between the thermal head 8 and the platen roller 9, and then winds via a rear guide roller 15. It is wound on the take-up reel 13. The printed sheet 5 is discharged by the image forming unit 10 to a sheet receiving tray (not shown) via the two rear guide plates 16 and 17.

As shown in FIGS. 1 to 3, the paper feed passage 7 has a fixed guide plate 18 which is curved in a side view from the paper feed roller 6 to the platen roller 9, and a circle of the fixed guide plate 18. A guide plate 19 that faces the outer side of the arcuate curved portion and is rotatable about a pivot shaft 20 is provided. On the upstream side of conveyance of the fixed guide plate 18, a pair of conveyance rollers 21 and 22 are provided. .

Then, the sheet 5 passing through the sheet feeding passage 7
The detecting means for detecting the presence or absence of the rotating shaft 25 rotatably supports a rotating shaft 25 on a bracket 24 projecting from the back surface of the one guide plate 19, and the rotating shaft 25 pierces the guide plate 19. An arm fixed so that a contact piece 28 having a substantially arcuate shape in a side view that protrudes from the provided window hole 26 to face the window hole 27 of the other fixed guide plate 18 is fixed while extending downward from the rotation shaft 25. A member to be detected 30 is attached to the lower end of 29 via a support 31 having an L shape facing downward in a side view.

When a paper jam occurs, etc.,
As shown in FIG. 4, the guide plate 19 is fixed to the fixed guide plate 18 by a handle 34 protruding from the rotatable guide plate 19.
It can be rotated so as to move away from it. As shown in FIGS. 2 and 4, the detected member 30 is a substrate 32.
A reflection plate 3 for reflecting the light from the light emitting portion of the light reflection type sensor 33 provided on the surface of
0a, semicircular control pieces 30b and 30b projecting downward from the left and right sides of the reflection plate 30a, a guide pin 30c protruding from the upper surface of the reflection plate 30a, and the guide pin 30c.
The guide pin 30c is inserted into a guide boss 31a provided on the support body 31 so as to be slidable up and down.
The pair of locking claws 30d and 30d are connected to the locking holes 31 of the support 31.
b, 31b. As a result, the detected member 30 is supported so as to be vertically movable with respect to the support 31 and not to fall off. When the arm 29 stands in a substantially vertical state, the tip of the contact piece 28 is placed in the both window holes 2.
6 and 27, the member to be detected 30 protrudes toward the back surface of the fixed guide plate 18 while the substrate 3 to which the control device is fixed.
2 is configured to approach the upper surface of the sensor 33 as a sensing unit fixed to the upper surface of the sensor 2 (see FIG. 2), and when the arm 29 rotates, the detected member 30 moves away from the upper surface of the sensor 33 (FIG. 2). 3).

The irradiation light from the light emitting portion of the sensor 33 is reflected by the lower surface of the reflecting plate 30a of the member 30 to be detected at the approaching position, and then is received by the light receiving portion to turn on the detection signal. . Next, the sheet feeding device 1 configured as described above
The operation of will be described. First, when the rotatable guide plate 19 approaches the fixed guide plate 18 and the sheet 5 does not pass between the guide plates 18 and 19, as shown in FIG. The tip of 28 passes through the window holes 26 and 27 from the back side of the guide plate 19 and the fixed guide plate 1
8 to the back side. In this state, the weight of the arm 29 and the detection target member 30 is reduced by the weight of the arm 2.
Since 9 stands substantially vertically, the detection signal of the sensor 33 is turned on from the positional relationship between the detected member 30 and the sensor 33 described above, and it is determined that there is no sheet 5 being conveyed by the control device (not shown). It

On the other hand, the sheet fed by the sheet feeding roller 6
The sheet of paper 5 is nipped by the pair of transport rollers 21 and 22,
After passing between the fixed guide plate 18 and the guide plate 19, the leading edge of the sheet 5 is conveyed to the vicinity of the platen roller 9, and in this state, the sheet is temporarily stopped. , 22 are driven to control the sheet 5 to pass through the image forming unit 10. When the sheet 5 is present between the window holes 26 and 27, the contact piece 28 is pushed away by the surface of the sheet 5 as shown by the solid line in FIG.
5, the arm 29 is rotated clockwise in FIG. 3, the detected member 30 at the lower end of the arm 29 is separated from the sensor 33 on the substrate 32, and the detection signal of the sensor 33 is turned off.
Becomes

When the sheet 5 passing between the fixed guide plate 18 and the guide plate 19 is jammed, the guide plate 19 is removed by the handle 34 in order to remove the sheet 5 as shown in FIG.
As indicated by the alternate long and short dash line, the fixed guide plate 18 is rotated away from the surface. In this state, the jammed paper 5 may be removed. When the guide plate 19 rotates about the pivot shaft 20, the guide plate 19 is located above the pivot shaft 20 and the guide plate 1
Arm 2 which rotates around a rotation shaft 25 on the back side of 9
9 tends to be vertical due to its own weight, but the lower surface of the contact piece 28 fixed to the rotating shaft 25 is the guide plate 1.
Since it is restrained by the lower end edge of the window hole 26 in 9, the arm 29 fixed to the rotating shaft 25 also rotates clockwise,
The detected member 30 at the lower end of the arm 29 is held at a position apart from the sensor 33 on the substrate 32, and the detection signal is turned off.

In this way, the guide plate 19 is fixed to the fixed guide plate 18
When it is rotated so as to move away from, the gap of the paper feed passage 7 becomes wider, so that the jammed paper 5 can be removed extremely easily. Also, with this rotating guide plate 19,
On the back surface side, the contact piece 2 rotates in a direction away from the fixed guide plate 18, so that the contact piece 28 does not interfere with the removal of the jammed paper 5.

Further, the detected member 30 at the lower end of the arm 29
Since it is not necessary to provide electrical wiring to the sensor 33 and the sensor 33 as a paper detection unit can be mounted on the substrate 32 fixed at a position away from the paper feed path 7, a harness or the like is not required for the wiring for the sensor 33. It is necessary and has the effect that the structure is extremely simple. The present invention can be variously modified without changing the gist thereof, and the contact piece 28 and the arm 29 may be integrally formed, or the image forming unit 10 may be formed.
This configuration may also be configured by inkjet printing.

[0017]

As described above, claim 1
In the sheet feeding device in the image forming apparatus of the invention described in (1), the sheet feeding path for guiding the sheet to the image forming section is configured by two guide plates facing the front and back surfaces of the sheet, and one of the two guide plates is provided. A sheet feeding device in an image forming apparatus, wherein a guide plate is provided with a sensing unit for detecting whether or not a sheet has passed, wherein one guide plate is provided so as to be separable from the other guide plate. The plate is provided with sensing means.

Therefore, when a paper jam occurs, in order to remove the paper, the one guide plate is simply moved away from the surface of the other fixed guide plate to widen the gap of the paper feeding path, and jam the jam. The effect is that the scraped paper can be easily removed. At this time, since the sensing means is provided on the separating guide plate, there is no inconvenience that the jammed paper is stuck to the sensing means.

The invention described in claim 2 is the same as claim 1.
In the paper feeding device of the image forming apparatus described in (1) above, a sensing unit rotatably attached to the one guide plate,
A contact piece projecting to the surface side of the other guide plate, and a detected part for sensing the displacement of the fixed sensing part in conjunction with the movement of the contact piece. is there.

The sensing means for sensing the presence or absence of paper is
The guide piece is composed of a contact piece and a detected part, is rotatable on the back side of the one guide plate, and the contact piece projects from the one guide plate toward the surface of the other guide plate. By moving the guide plate away from each other, the contact piece can be reliably moved away from the other guide plate. Further, the detected part is interlocked with the movement of the contact piece, and the distance from the fixed position of the sensing part varies, so that the sensing part can detect the presence or absence of the paper. Since the sensing unit can be provided at a position distant from the position, the degree of freedom in setting the location where the sensing unit is installed is increased.

Further, in the invention described in claim 3, in the sheet feeding device in the image forming apparatus described in claim 1 or 2, the contact piece and the detected portion in the sensing means are guided by the one guide. It is attached so as to rotate integrally with a rotation shaft provided on the back side of the plate. As described above, since the contact piece and the detected portion are provided so as to rotate integrally with the rotation shaft, a proportional relationship between the movement of the contact piece and the detected portion is established, and the detected portion and the sensed portion are sensed. There is also an effect that it is possible to reliably detect the presence / absence of the sheet due to the change in the distance from the unit.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a sheet feeding device.

FIG. 2 is a side cross-sectional view of a main part of the configuration of a paper feed path in a state in which paper does not pass.

FIG. 3 is a side cross-sectional view of a main part of a configuration of a paper feed path when a sheet passes and when one guide plate rotates.

FIG. 4 is a perspective view of a rotating guide plate, a contact piece, an arm, and a detected member.

[Explanation of symbols]

 1 Paper Feeding Device 5 Paper 7 Paper Feeding Path 10 Image Forming Section 18 Fixed Guide Plate 19 Guide Plate 20 Pivot Shaft 25 Rotating Shaft 26, 27 Window Hole 28 Contact Piece 29 Arm 30 Detected Member 31 Support 32 Substrate 33 Sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 1/00 108 H04N 1/00 108J

Claims (3)

[Claims] 1. A paper feed path for guiding and feeding a sheet to an image forming section is constituted by two guide plates facing the front and back surfaces of the sheet, and one of the guide plates is used to determine whether or not the sheet passes. In a sheet feeding device in an image forming apparatus provided with sensing means for detecting, the one guide plate is provided so as to be separable from the other guide plate, and the sensing means is provided on one guide plate. A sheet feeding device in a characteristic image forming apparatus. 2. A sensing means mounted rotatably with respect to the one guide plate is fixed in contact with a contact piece projecting to the surface side of the other guide plate and in conjunction with the movement of the contact piece. The sheet feeding device in the image forming apparatus according to claim 1, wherein the sheet feeding device is configured by a detected part for sensing by a displacement of a distance from the sensing part. 3. The contact piece and the detected portion of the sensing means are attached so as to rotate integrally with a rotary shaft provided on the back surface side of the one guide plate. 1
Alternatively, the sheet feeding device in the image forming apparatus according to claim 2.