JP2001151367A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that vibration of a separation pad can be sufficiently suppressed because rigidity of a part for supporting the separation pad is weak. SOLUTION: A metal plate 19 arranged between an image forming portion C and a paper feeding cassette 2 for storing a sheet S supports the separation pad 2b for separating the sheet fed from the paper feeding cassette 2. Thus, the vibration of the separation pad 2b when the sheets are separated one by one can be suppressed, and uncomfortable noise occurrence can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile and the like.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing the construction of a facsimile apparatus as an example of a conventional image forming apparatus, which will be described.

In this facsimile apparatus, an original reading device A is arranged at the upper left in the figure, and an image forming apparatus B is arranged at the lower right in the figure. Then, information such as a document read by the reading device A is transmitted to a facsimile device of another machine in the case of the facsimile mode, and is recorded on a recording medium (hereinafter referred to as recording paper) by the image forming device B in the case of the copy mode. .

An original reading apparatus A reads information written on an original, and includes an original mounting table 114a and an auxiliary mounting table 1a.
The document O stacked on the sheet 14b is separated one by one by a separation roller 114c and a separation piece 114d pressed against the separation roller 114c, the document O is transported by a pair of transport rollers 114e, and the document O is read by a pressing means 114f. The information of the original O is read while being pressed against and brought into close contact. The read original O is discharged out of the reading device A by the discharge roller pair 114g.

The image forming apparatus B irradiates a photosensitive drum 107 as a rotating image carrier with a light image based on image information read from an external device or the like from the optical system 101, and the surface of the photosensitive drum 107 is illuminated. Is selectively exposed to form a latent image corresponding to the image information. Then, a toner image is formed on the photosensitive drum 107 in the image forming unit formed as a process cartridge C.

On the other hand, below the image forming apparatus B, a sheet feeding section D
Is disposed, and the uppermost sheet of the recording paper S loaded in the paper feed cassette 102 which is detachably mounted from one end of the paper feed unit D is fed to the paper feed roller 102 b and the separation pad 10.
2c, the sheets are separated and fed one by one,
And conveys it to the transfer means 104 of the image forming apparatus B after being reversed through the U-turn path.

Then, the toner on the photosensitive drum 107 is transferred to the recording paper S by applying a voltage having a polarity opposite to that of the toner image formed on the photosensitive drum 107 by the transfer means 104. Thereafter, the recording paper S is conveyed to the fixing unit 105, and heat and pressure are applied to fix the toner on the recording paper S to the recording paper S.

The recording paper S after fixing passes through the face-down paper discharge guide 108 when the paper is discharged face-down, and the recording paper S is inverted and discharged to the face-down tray 106a when the paper is face-up, and is discharged to the face-up tray 106b when the paper is face-up. . Face-up discharge and face-down discharge can be selected by switching the flapper 109.

In order to separate the sheet cassette 102 from the image forming section B, a metal plate 110 is provided on substantially the entire upper surface of the sheet cassette 102 so as to escape the sheet feed roller 102b. Is fixed to a circuit board 111 having a control circuit.

[0010] The separation pad 102c is a paper guide section 102d.
The center of rotation 102e is dropped into a U-shaped groove (not shown) of the cassette frame 112, and fixed by a pressing member (not shown) from above to be rotatably supported. The recording paper S that is urged in the direction of the arrow by the separation spring 102f and pressed against the paper feed roller 102b to be sent out can be separated and separated.

[0011]

However, in the above-described conventional example, the cassette frame 112 is made of a resin material also serving as an exterior, and the rigidity of the portion supporting the separation pad 102c is reduced. I have. As a result, when the recording paper S is separated, the recording paper S and the separation pad 102c are separated.
Pad 102c generated by sticking
It is extremely difficult to suppress the vibration of the recording paper S and the cassette frame 112, and the noise generated by the vibration of the separation pad 102c may be unpleasant.

The present invention has been made in view of the above problems, and has as its object to remarkably enhance the rigidity of a support portion of a separation pad and suppress vibration of the separation pad during a sheet feeding operation. Another object of the present invention is to prevent generation of unpleasant noise generated by vibration of the separation pad.

[0013]

According to a first aspect of the present invention, there is provided an image forming apparatus including a sheet feeding device for supplying a sheet to an image forming unit, wherein the image forming unit is disposed. An apparatus main body, a paper feed cassette detachably provided in the apparatus main body and containing sheets to be supplied, and a paper feed cassette provided in the apparatus main body at a front side in a mounting direction of the paper feed cassette and mounted on the apparatus main body. Paper feeding means for feeding out sheets from a paper feeding cassette, a separation pad provided for separating the sheets fed by the paper feeding means one by one, and a space between the image forming section and the paper feeding cassette. And a metal plate disposed on the metal plate, and the separation pad is supported by the metal plate.

Further, the present invention is characterized in that a bent portion for reinforcement is formed in the metal plate.

In the present invention, the sheet cassette may be mounted below the image forming section, and the metal plate may be disposed above the sheet cassette mounted on the apparatus main body and the sheet cassette. Provided so as to cover substantially the entire upper surface of the paper feed cassette to separate from the image forming unit, and provided a passing hole for guiding the sheet sent out by the paper feeding unit to the image forming unit on the metal plate, The separation pad is supported on the front side of the passage hole in the mounting direction of the sheet cassette.

The present invention is characterized in that a reinforcing bent portion is formed on a front side of the support position of the separation pad in the mounting direction of the sheet feeding cassette on the metal plate.

The present invention is characterized in that the separation pad is supported by the metal plate via a support member that movably supports the separation pad so that the separation pad can contact the sheet feeding means.

The present invention is characterized in that a pressing spring for pressing the separation pad against the paper feeding means is interposed between the separation pad and the apparatus main body.

According to the present invention, the apparatus main body is composed of a main body frame having the image forming section and a cassette frame for accommodating the paper feed cassette, and the metal frame is formed by the main body frame and the cassette frame. The plate is sandwiched and fixed.

[0020] The present invention is characterized in that the separation pad is supported on the metal plate by screws which are inserted through the metal plate and fastened to the cassette frame.

The present invention is characterized in that an image reading section for reading an image of a document is mounted on the apparatus main body.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which a paper feeder according to a first embodiment of the present invention is applied to a facsimile machine will be specifically described with reference to the drawings. Here, the description will be made in the following order. Overall configuration of facsimile machine Configuration of reader for reading images Configuration of image forming apparatus for recording information Configuration of cassette paper feed unit

<< Overall Configuration of Facsimile Apparatus >> FIG. 1 is an explanatory view showing the configuration of a facsimile apparatus having an image forming apparatus equipped with a process cartridge according to the present invention, and FIG.
FIG.

In this facsimile apparatus, as shown in FIG. 1, an image reading apparatus A is arranged on the near side of the apparatus (upper left in the figure), and an image forming apparatus B is arranged in the lower part (lower right in the figure). ing. Then, information such as a document read by the reading device A is transmitted to a facsimile device of another machine in the case of the facsimile mode, and is recorded on recording paper by the image forming device B in the case of the copy mode.

As shown in FIG. 1, the image forming apparatus B irradiates a light image based on image information from an optical system 1 to form a toner image on a photosensitive drum 7 as an image carrier. Then, in synchronization with the formation of the toner image, the recording paper S is fed from either the cassette paper feeding unit D arranged at the bottom of the main body or the multi paper feeding unit E arranged at the upper part on the back side of the main body, and is conveyed by the conveying means 3. Then, the toner image formed on the photosensitive drum 7 is transferred to the recording paper S by the transfer means 4 in the image forming unit formed as a process cartridge C, and the recording paper S is conveyed to the fixing means 5 and transferred. The toner image is fixed and discharged onto the tray 6a or 6b.

{Reading Device} The reading device A is for reading the written information of the document O. As shown in FIG. 1, the original O stacked on the original placing table 14a and the auxiliary placing table 14b is separated one by one by a separating piece 14d pressed against a separating roller 14c, and the original O is transported by a conveying roller pair 14e. And the information of the original O is read while the original O is pressed against and brought into close contact with the contact type sensor of the reading means 15 by the pressing means 14f. After reading, the original O is discharged out of the reading device A by the discharge roller pair 14g.

The reading means 15 includes an LED as a light source.
Irradiates the information writing surface of the original O with light, forms an image of the reflected light on a photoelectric conversion element via a short focus imaging lens, and reads the information.

The document table 14a is provided with a slider 14h slidable in a direction perpendicular to the direction of transport of the document O (width direction of the document O).
The document table 14 by sliding the
By aligning both sides of the document O stacked on the document a, it is possible to prevent skew of the conveyed document.

{Image Forming Apparatus} Next, the configuration of each part of the image forming apparatus B that forms an image in accordance with a recording signal will be described.
Optical system, recording paper conveying means, transfer means, fixing means,
The paper discharging means and the process cartridge mounting means will be described in this order.

(Optical System) The optical system 1 irradiates a light image on the photosensitive drum 7 by irradiating light based on image information read from an external device or the like. As shown in FIG. A laser diode 1b in 1a,
A polygon mirror 1c, a scanner motor 1d, an imaging lens 1e, and a reflection mirror 1f are housed therein.

For example, when an image signal is sent from a facsimile machine of another machine, the laser diode 1b emits light in accordance with the image signal and irradiates the polygon mirror 1c as image light. The polygon mirror 1c is rotated at high speed by a scanner motor 1d, and the image light reflected by the polygon mirror 1c irradiates the rotating photosensitive drum 7 via the imaging lens 1e and the reflection mirror 1f, and the surface of the drum 7 is irradiated. The latent image is selectively exposed to form a latent image corresponding to the image information.

(Recording Paper Conveying Means) In the case of the facsimile apparatus according to the present embodiment, a cassette paper feeding section D having a paper feeding cassette 2 disposed at the bottom of the apparatus and detachable from the front side of the apparatus (left side in FIG. 1). And a multi-sheet feeding unit E provided vertically in the upper part on the back side of the apparatus (right side in FIG. 1).

The cassette paper feeding section D is a paper feeding section limited to supplying recording paper S of a standard paper size of A4 or letter. A pickup roller 2a for sending out recording paper S from the paper supply cassette 2 and a pressing spring 2
c and is pressed against the pickup roller 2a,
A separation pad 2b for separating the recording paper S one by one between them is provided. Note that a high friction member is attached to the separation pad 2b at a portion where the separation pad 2b is pressed against the pickup roller 2a.

The multi-sheet feeding section E includes a recording sheet loading table 13 for supporting the recording sheet S, and a multi-slider slidably provided in a direction perpendicular to the conveying direction of the recording sheet S (in the width direction of the recording sheet S). Reference numeral 13a is provided so that recording paper of an irregular size, such as a postcard or an envelope, as well as a standard size, can be supported and fed with both sides aligned. A pickup roller 13b for sending out the recording paper S supported by the recording paper loading table 13 is provided to the multi paper feeding unit E.
And a separation pad 13c that is urged by a pressing spring 13d to press against the pickup roller 13b and separate the recording paper S one by one between the pressing rollers 13b.

The conveying means 3 for conveying the recording paper S includes
An auxiliary roller pair 3a that is disposed on the right side of the image forming apparatus B in FIG. 1 and conveys the recording paper S sent from the cassette paper feeding unit D, and a transfer unit that transfers the recording paper S conveyed by the auxiliary roller pair 3a, which will be described later. And a transport roller pair 3b for transporting the paper toward the roller. The recording sheet S sent from the multi sheet feeding unit E is directly delivered to the pair of conveying rollers 3b. The recording sheet S is conveyed to the image transfer section so that the conveying roller pair 3b synchronizes with the image forming operation. Then, the recording sheet S after the image transfer is conveyed to the fixing unit 5 by the guide member 3c, and the recording sheet S after the fixing by the fixing unit 5 is discharged by the discharging unit.

(Transfer Unit) The transfer unit 4 transfers the toner image formed on the photosensitive drum 7 in the image forming unit to the recording paper S. The transfer unit 4 of the present embodiment is as shown in FIG. And a transfer roller 4a. That is,
The recording paper S is pressed against the photosensitive drum 7 of the mounted process cartridge C by the transfer roller 4a, and a voltage having a polarity opposite to that of the toner image formed on the photosensitive drum 7 is applied to the transfer roller 4a. The toner on the drum 7 is transferred to the recording paper S.

(Fixing Means) The fixing means 5 fixes the toner image transferred onto the recording paper S by applying a voltage to the transfer roller 4. As shown in FIG. 1, the configuration includes a driving roller 5a that is driven and rotated, and a fixing member 5c that has a heater 5b inside and has a sheet member that is pressed against the driving roller 5a and is driven to rotate. That is, the recording paper S on which the toner image has been transferred by the image forming unit is
When the toner passes through the space between the fixing member 5a and the fixing member 5c, pressure is applied by the pressing of the two members 5a and 5c, and heat is applied by the heat generated by the heater 5b, so that the toner on the recording paper S is fixed to the recording paper S.

(Paper Discharge Means) The recording paper S on which the toner image is fixed is stacked on the face-down tray 6a or the face-up tray 6b.

In the case of face-down discharge, the flapper 6d is set to the position indicated by the solid line in the figure by a lever (not shown), and the recording paper S is discharged face-down with the upper surface of the flapper 6d by the fixing discharge roller pair 6c. Guide 6
e is guided and transported by the face down roller pair 6
By f, the sheets are stacked on the face down tray 6a in the page order with the print surface facing down.

In the case of face-up discharge, the recording paper S is set to the position indicated by the broken line in FIG.
The paper is conveyed while being guided by the lower surface of the flapper 6d, and is stacked on the face-up tray 6b with the printing surface facing upward.

In order to facilitate the jam clearance, the face-down discharge guide 6e is rotatably supported by the main body about a rotation center 6g, and is normally urged clockwise by a spring (not shown). A reverse transport path is formed so that it can be opened in the counterclockwise direction during jam processing (see FIG. 3).

(Process Cartridge Mounting Means) A cartridge mounting means for mounting the process cartridge C is provided in the image forming apparatus B. The mounting and dismounting of the process cartridge C with respect to the apparatus main body is performed from the front side by opening the opening / closing cover 16 integrated with the image reading unit A in the front direction toward the apparatus as shown in FIG. As described above, the apparatus main body is configured to open only the opening / closing cover 16, so that the user does not feel complicated.

The original table 14a and the auxiliary table 1
Since the transport path for the document O is integrated with the transport path 4b, a step and a gap at a joint portion of the path for sending the document are minimized. As shown in FIG. 3, a rotation center 17 is provided at a lower front portion of the apparatus main body.
When a is released by a lever (not shown), the opening / closing cover 16 is configured to rotate with respect to the apparatus main body and open in the front direction.

When the opening / closing cover 16 is opened, a cartridge mounting space is provided in the apparatus main body, and guide grooves 18 are provided on the left and right wall surfaces of the space.
The process cartridge C can be mounted on the image forming apparatus B by inserting the process cartridge C along the drum shaft along the guide groove 18 and closing the opening / closing cover 16.

{Structure of Cassette Paper Feeding Unit} As shown in FIGS. 1 and 4, the paper feeding cassette 2 covers almost the entire upper surface of the paper feeding cassette 2 to separate the image forming unit B from the paper feeding cassette 2. A metal plate 19 is provided along the upper surface of the sheet cassette 2. The width of the recording paper S is set on the metal plate 19 at the leading end of the recording paper S placed in the paper feed cassette 2 in order to arrange the pickup roller 2a and the separation pad 2b and to allow the recording paper S to pass through. Passage hole 19a having the above size
Is provided. In forming the passage hole 19a, a bent portion 19b is provided above the metal plate 19.

The circuit board 20 having the control circuit is a metal plate 1
9 and the metal plate 21, and is fixed to the metal plate 19 in a substantially horizontal state on the front side of the device between the passage hole 19a and the bent portion 19b, and the circuit board 20 is bent by the bent portion 19b.
And a sheet feeding section D including the pickup roller 2a. Further, the rigidity of the metal plate 19 is increased by the bent and raised portion 19b.

The support member 2d for rotatably supporting the separation pad 2b is formed on the upper surface of the metal plate 19 and the passage hole 19a.
At the back of the device. In order to secure the mounting strength of the support member 2d to the main body, a screw hole 22b is provided in the pedestal portion 22a of the cassette frame 22, so that the metal plate 19 is sandwiched between the pedestal portion 22a of the cassette frame 22 and the support member 2d. Screw 2e
The strength of this portion is secured by a configuration in which the support member 2d, the metal plate 19, and the pedestal portion 22a of the cassette frame 22 are integrated.

Further, a downward bent portion 19c is formed in substantially the entire width of the metal plate 19 on the back side of the apparatus from the position where the support member 2d of the metal plate 19 is fixed, and the support member is formed. The structure is such that the strength of the portion where 2d is fixed can be significantly increased.

Further, the metal plate 19 is connected to the cassette frame 2.
2 and a main body frame provided with an image forming portion B is placed thereon, and the cassette frame 2 is placed at a predetermined position.
2 are screwed and fixed to a plurality of screw holes provided in the screw 2. In this way, the metal plate 19 is sandwiched between the cassette frame 22 and the main body frame having the image forming portion B to be integrally formed, so that the rigidity of the entire apparatus including the support portion of the separation pad 2b is improved. .

As described above, by increasing the rigidity of the support structure of the separation pad 2b, the vibration of the separation pad 2b generated when separating the recording paper S can be suppressed, and unpleasant noise can be reliably prevented. be able to.

[0051]

As described above, according to the present invention,
By supporting the separation pad on a metal plate located between the image forming unit and the paper feed cassette, the rigidity of the support portion of the separation pad can be strengthened, and the vibration of the separation pad during the paper feeding operation can be suppressed. In addition, unpleasant noise generated by the vibration of the separation pad can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view for explaining a configuration of a facsimile apparatus having a sheet feeding device according to the present invention.

FIG. 2 is an external perspective view of the facsimile apparatus shown in FIG.

FIG. 3 is a diagram illustrating a configuration when an image reading unit of the facsimile apparatus illustrated in FIG. 1 is opened.

FIG. 4 is an exploded perspective view illustrating a configuration of a cassette sheet feeding unit of the facsimile apparatus shown in FIG.

FIG. 5 is a longitudinal sectional view showing an example of a conventional facsimile machine.

[Explanation of symbols]

 Reference Signs List A reading device B image forming device C process cartridge D cassette feeding unit E multi-feeding unit O original S recording paper (sheet) 1 optical system 1a optical unit 1b laser diode 1c polygon mirror 1d scanner motor 1e imaging lens 1f reflection mirror Reference Signs List 2 paper feed cassette 2a pickup roller 2b separation pad 2c pressing spring 2d support member 3 transport means 3a auxiliary roller pair 3b transport roller pair 3c guide member 4 transfer means 4a transfer roller 5 fixing means 5a drive roller 5b heater 5c fixing member 6a face down Tray 6b Face-up tray 6c Fixing discharge roller pair 6d Flapper 6e Face-down discharge guide 6f Face-down roller pair 6g Rotation center 7 Photoconductor drum 13 Recording paper loading table 13a Multi-slider 1 b Pickup roller 13c Separation pad 13d Pressing spring 14a Document table 14b Auxiliary table 14c Separation roller 14d Separator piece 14e Transport roller pair 14f Pressing means 14g Discharge roller pair 14h Slider 15 Reading means 16 Opening / closing cover 16a Lock section 17 Rotating center 18 Guide Groove 19 Metal plate 19a Passing hole 19b Bend-up portion 19c Bend portion 20 Circuit board 22 Cassette frame 22a Base portion 22b Screw hole

Claims (9)

[Claims] 1. An image forming apparatus including a sheet feeding device for feeding a sheet to an image forming unit, wherein: an apparatus main body in which the image forming unit is disposed; A sheet feeding cassette for storing sheets, a sheet feeding unit provided at a front side of the sheet feeding cassette in the apparatus main body in the mounting direction of the sheet feeding unit, and feeding sheets from the sheet feeding cassette mounted on the apparatus main body; A separation pad provided for separating the sheets sent one by one, and a metal plate disposed between the image forming unit and the paper feed cassette, wherein the separation pad is provided on the metal plate. An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein a reinforcing bent portion is formed on the metal plate. 3. The image forming apparatus according to claim 1, wherein the sheet cassette is mounted below the image forming unit so that the metal plate can be attached to the image forming unit. The sheet feeding cassette is provided so as to cover substantially the entire upper surface of the sheet feeding cassette so as to be separated therefrom, and a passing hole for guiding the sheet fed by the sheet feeding means to the image forming section is provided in the metal plate. The image forming apparatus according to claim 1, wherein the separation pad is supported on a front side of the passage hole in a paper cassette mounting direction. 4. The image forming apparatus according to claim 3, wherein a bent portion for reinforcement is formed on a front side of the support position of the separation pad in the mounting direction of the sheet feeding cassette on the metal plate. 5. The apparatus according to claim 3, wherein the separation pad is supported on the metal plate via a support member that movably supports the separation pad so that the separation pad can contact the sheet feeding unit. The image forming apparatus as described in the above. 6. An image forming apparatus according to claim 5, wherein a pressing spring for pressing said separation pad against said sheet feeding means is interposed between said separation pad and said apparatus main body. 7. The apparatus main body includes a main body frame having the image forming unit and a cassette frame for storing the paper feed cassette, and the metal plate is formed by the main body frame and the cassette frame. 7. The fixing device according to claim 1, wherein the fixing device is sandwiched and fixed.
Item 10. The image forming apparatus according to item 1. 8. The image forming apparatus according to claim 7, wherein the separation pad is supported on the metal plate by a screw inserted into the metal plate and fastened to the cassette frame. 9. The image forming apparatus according to claim 1, wherein an image reading unit for reading an image of a document is mounted on the apparatus main body.