JPH0423863Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a paper feeding mechanism, particularly for feeding paper one sheet at a time using a self-weighted paper feeding roller, such as in electronic copying machines and printers. Regarding the paper feeding mechanism.

(Prior art) An example of a paper feeding mechanism using a self-weight paper feeding roller is
For example, it is disclosed in Japanese Utility Model Publication No. 58-48279.

(Problem to be solved by the invention) In the paper feed mechanism with such a self-weight paper feed roller, when the paper feed cassette is not installed,
The paper feed roller descends until it touches the bottom of the main body. When you next try to install the paper feed cassette in this condition, the paper feed roller has descended too far and its upward movement is obstructed for some reason. When installing the paper feed cassette, there were cases where the paper feed cassette could not be inserted smoothly.

Therefore, the main purpose of this invention is to provide a paper feeding mechanism in which the paper feeding cassette can be easily installed and removed.

(Means for Solving the Problems) Simply put, this invention consists of a paper feed cassette, a support plate provided at the bottom of the paper feed cassette, and a support plate for holding paper in an accumulated manner on the paper feed cassette. A paper feed roller is provided above the leading edge of the supported paper and uses its own weight to contact the top layer of paper to take out the paper, a notch formed in the leading edge of the support plate, and a feeding roller. Provided on the main body below the paper cassette,
This paper feeding mechanism includes a stopper member that faces the paper feeding roller through a notch and prevents the paper feeding roller from descending beyond a certain level.

(Function) When the paper feed cassette is attached, the paper feed roller is pushed up by the paper stored in the paper feed cassette and takes out the paper normally. When the paper feed cassette is removed, the paper feed roller descends due to its own weight. Then, the peripheral side of the paper feed roller comes into contact with a corresponding stopper member provided below. Therefore, the paper feed roller does not descend below a certain height.

(Effect of the invention) According to this invention, the paper feed roller does not descend below a certain height even when the paper feed cassette is removed, which means that the vertical movement of the paper feed roller changes when the paper feed cassette is installed or removed. Since the amount can be reduced, the next time the paper feed cassette is installed, it can be easily installed.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIG. 1 is a structural diagram showing an example of an electronic copying machine as an embodiment of this invention. It should be pointed out in advance that this invention can be used not only for such electronic copying machines but also as a paper feeding mechanism for printers and other devices.

The electronic copying machine 10 includes a main body 12, and a document table 14 made of, for example, a transparent glass plate is supported on the upper surface of the main body 12 so as to be movable in the left-right direction. A document cover 16 is attached to the upper surface of the document table 14 so as to be openable and closable.

Inside the main body 12 is a photosensitive drum 18 whose circumferential surface is coated with a photoconductive layer, that is, a photosensitive material, such as amorphous silicon.
It is provided so as to be rotatable in the direction of the arrow. A short focus lens array 20 is mounted on the top of the photoreceptor drum 18.
is fixedly mounted so that its optical axis is oriented almost vertically. This short focus lens array 20
A document image formed by the document placed on the document table 14 is formed on the circumferential surface of the photosensitive drum 18 .

A charging corotron 2 is provided on the upstream side of the short focus lens array 20 in the rotational direction of the photoreceptor drum 18 for uniformly charging the photoreceptor drum 18 to a predetermined polarity.
2 is provided. An exposure lamp 24 made of a halogen lamp or the like is provided above the charging corotron 22 to expose the surface of the document placed on the document table 14 . The light from the exposure lamp 24 is reflected by a reflecting mirror 26 to subject the above-mentioned original to slit exposure.

An electrostatic latent image of the original is formed on the photoreceptor drum 18 by the charging corotron 22, the exposure lamp 24, the short focus lens array 20, and the original placed on the original platen 14.

A developing device 28 for developing the electrostatic latent image as described above with toner is provided near the circumferential side of the photosensitive drum 18 and downstream of the short focus lens array 20. A mixture of toner and carrier, that is, a developer is stored in the developing device 28 , and this developer is conveyed toward the photoreceptor drum 18 by a magnetic roller 30 . A spike of developer is formed on the portion of the magnetic roller that faces the photoreceptor drum 18, and when the tip of the spike comes into contact with the photoreceptor drum 18, static electricity formed by, for example, a positive charge is generated. For example, negatively charged toner is attached to the latent image. In such a developing device, from a toner box 32 provided above the developing device, as necessary,
Toner is supplied.

A paper feeding mechanism 34 is formed at the bottom of the main body 12, and a paper 36 is taken out from the paper feeding mechanism 34 as will be described later, and the paper is brought to the vicinity of the circumference of the photosensitive drum 18. A transfer corotron 38 for transferring the toner image developed by the developing device 28 onto the paper 36 is located near the circumferential side of the photosensitive drum 18 and in a portion where the paper 36 is supplied.
will be provided. A separation claw 40 is provided downstream of the transfer corotron 38, and the paper to which the toner image has been transferred is separated from the photoreceptor drum 18 by the separation claw 40.
and is brought to a fixing device 44 by a transport conveyor 42. The fixing device 44 fixes the toner image formed on the paper by applying heat and pressure using, for example, a pair of rollers. The fixed paper is discharged onto the paper discharge tray 46.

Note that toner remaining on the photoreceptor drum 18 without being completely transferred onto the paper 36 by the transfer corotron 38 is scraped off by a cleaning device 47 provided at the most downstream position in the rotational direction of the photoreceptor drum 18 .

Next, the paper feed mechanism 34 will be described in detail with reference to FIGS. 1 and 2. Paper feeding mechanism 34 includes a paper feeding cassette 48. This paper feed cassette 48
is removably attached to an insertion opening provided at the bottom of the main body 12. Inside the paper feed cassette 48,
A support plate 50 for holding or supporting the paper 36 in a stacked manner is provided thereon with its tip (rightward in FIG. 1) lifted upward and inclined. A notch 5 is provided at the tip of the support plate 50.
0a is formed, and the main body 1 below the paper feed cassette 48
2, a stopper member 52 is provided at the position of the notch 50a.

A roller shaft 54 is provided above the front end of the paper 36 stored in the paper feed cassette 48, and a portion of the roller shaft 54 has a driving pulley 56 (a third drive pulley 56) driven by a motor (not shown). 2
) is installed. Another roller shaft 58 is provided in front of the roller shaft 54, and a driven pulley 60 is fixed to this roller shaft 58. A drive belt 62 is stretched between the driving pulley 56 and the driven pulley 60. The roller shafts 54 and 58 are connected by a roller arm 64, and paper feed rollers 66 are fixed to both ends of the roller shaft 58, with the roller arm 64 in between. Therefore, rotational force is applied to the paper feed roller 66 by the motor, that is, the driving pulley 56 via the roller shaft 58.

A paper feed roller lifter 68 is rotatably supported at a portion of the roller shaft 58 sandwiched between the roller arms 64. A sleeve shaft 70 is held at the tip of the paper feed roller lifter 68, and this sleeve shaft 70 is bent into a crank shape and both ends thereof are rotatably supported outside the main body 12. A lift roller or sleeve 72 is located on the sleeve shaft 70 at a position corresponding to the paper feed roller 66.
It is held freely rotatable with respect to 0.

Both ends of the sleeve shaft 70 pass through the body 12 but are not in a supporting relationship with the body 12, and are coupled to a solenoid (not shown) via a hook 74. Also, the push-up lever 76 is connected to the lever shaft 78.
By rotating around , the sleeve shaft 70 is actuated in the direction of arrow A in FIG.

In front of the paper feed roller 66, an independent sub-roller 78 and a jam lid 80 are further provided. When a jam occurs therein, the jam lid 80
This is so that the jammed paper can be removed by removing the paper. The inner wall of the jam lid 80 is folded back into a U-shape, and a pair of conveying rollers 82a and 82b are provided in the folded portion. A shutter 84 is provided in front of the transport rollers 82a and 82b in the paper feeding direction so as to be rotatable about a shaft 83, that is, to be freely retractable from the bottom to the top. This shutter 84 is for determining the timing of supplying paper in the direction of the photosensitive drum 18, that is, to the transfer section. The previous conveyance roller (driven roller) 82b is interlocked with this shutter 84.

When the paper feed cassette 48 is attached, the front end of the paper 36 is supported by the stopper member 52 through the notch 50a of the support plate 50, as shown in FIG. Then, the paper feeding roller 66 descends due to its own weight and comes into contact with the top layer of paper, and as the paper feed roller 66 rotates, the paper 36 is pushed forward and taken out. In this state, the taken out paper 36 is held between the driving roller 82b and the spring provided in relation to it. Therefore, the conveyance force by the roller 82b is not very strong, and the paper 36 slips and stops with the leading edge of the paper 36 in contact with the shutter 84.

Thereafter, when the sleeve shaft 70 is rotated at a predetermined timing in the direction of the arrow A shown in FIG. Since the distance between the sleeve 72 and the paper feed roller 66 is kept constant by the paper feed roller lifter 68, the paper feed roller 66 is pushed upward around the roller shaft 54, and the paper feed roller 66 is moved to the position shown in FIG. The contact between the paper roller 66 and the paper 36 is released. At this time, the shutter solenoid (not shown)
is operated, the shutter 84 is rotated around the shaft 83 and opened, and the driven roller 8 is opened accordingly.
2a strongly contacts the driving roller 82b. Therefore, by the rotation of the two rollers 82a and 82b, the previously stopped paper 36 is transferred toward the photosensitive drum 18.

When the paper feed cassette 48 is removed, the paper feed roller 66 descends due to its own weight, and the surface of the roller 66 comes into contact with the stopper member 52, as shown in FIG. The height of this stopper member 52 is set approximately equal to the height of the support plate 50 of the paper feed cassette 48 at that position. Therefore,
The paper feed roller 66 does not descend below that height, and the amount of vertical displacement of the paper feed roller 66 when the paper feed cassette 48 is attached and removed is not so large as in the conventional case. That is, even if the paper feed cassette 48 is removed, the paper feed roller 66 does not descend until it comes into contact with the bottom of the main body, as shown in FIG. The paper feed cassette 48 can be installed smoothly without being obstructed in its upward movement.

Since the stopper member 52 has a simple structure, it does not require much space, and therefore the paper feeding cassette can be easily installed and removed without increasing the size of the entire paper feeding mechanism.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing an example of an electronic copying machine as an embodiment of this invention. FIG. 2 is a partially cutaway perspective view showing the main parts of the embodiment shown in FIG. Third
4 and 5 are state diagrams in different states for explaining the operation of this embodiment, respectively. FIGS. 3 and 4 show the paper feeding state, and FIG. 5 shows the paper feeding state. Shows the state with the paper cassette removed. In the figure, 34 is a paper feed mechanism, 36 is paper, and 48
is a paper feed cassette, 50 is a support plate, 50a is a notch,
52 is a stopper member, 66 is a paper feed roller, and 72 is a sleeve.

Claims (1)

[Claims for Utility Model Registration] 1. A paper feed cassette, a support plate provided at the bottom of the paper feed cassette for holding paper in a piled manner thereon, and a leading end of the paper supported by the support plate. A paper feed roller provided above the paper feed cassette and used to contact the top layer of paper under its own weight to take out the paper, a notch formed at the tip of the support plate, and a main body below the paper feed cassette. A paper feed mechanism, comprising a stopper member that faces the paper feed roller through the notch and prevents the paper feed roller from lowering beyond a certain level. 2. The support plate is inclined so that the leading end of the paper is upward, and the height of the stopper member is equivalent to the corresponding portion of the support plate, Claim 1 of the Utility Model Registration Claim. Paper feeding mechanism as described.