JPH0676147B2 - Paper feeder for electrophotographic printer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device of an electrophotographic printer.

2. Description of the Related Art Conventionally, in an electrophotographic printer, as shown in FIG. 9, an upper frame 102 is vertically rotatably connected to a lower frame 101 to form a main body 103.
03 is provided with a photoconductor, a developing unit for developing the electrostatic latent image formed on the photoconductor, a transfer unit, and a fixing unit.
The paper 105 of the paper feed cassette 104 attached to the paper is pulled out by the pick up roller 106, and further fed by the feed roller 107 toward the photoconductor along the paper feed guide plate 108 and the front cover 109. .

However, since the paper 105 is pulled out from the front edge of the paper feed cassette 104, is turned into a U-shape, and is sent to the photoconductor, the paper feed guide plate 108 and the front cover are not provided. Easily clogged with 109. For this reason, the front cover 109 is detachably attached to the lower frame 101, and the front cover 109 is removed during the jam treatment. However, a mistake occurs in driving without forgetting to attach the front cover 109. Generally, a detector 110 for detecting the open state of the upper frame 102 is provided, but in addition to this detector 110, a detector for notifying the operator of the unattached state of the front cover 109 must be separately provided.

Also, although not shown in the drawing, the U-paper is fed from the front edge of the paper feed cassette.
There is also one in which the direction is changed to a letter shape and is supplied to the photoconductor, and a guide portion protruding from the front surface of the main body 103 is provided at the front portion of the sheet feeding cassette. Since it protrudes to the front of the main body 103, it is easy to perform a jam treatment, but the size of the paper feed cassette is increased. This is
Since it is necessary to prepare a plurality of paper cassettes according to the size of the paper, the number of packing packages increases and a large storage space is required, which is disadvantageous.

Means for Solving the Problems A main body in which an upper frame is vertically rotatably connected to a lower frame is provided, and a photosensitive member and a developing unit for developing an electrostatic latent image formed on the photosensitive member are provided in the main body. A sheet feeding cassette provided with a transfer section and a fixing section and stacking and storing a large number of sheets, a pickup roller facing the front upper part of the sheet feeding cassette, and rising from the front edge of the sheet feeding cassette upwardly of the pickup roller. The lower frame is provided with a binding guide plate which is curved rearward with the periphery thereof toward the developing unit, and a guide surface facing the curved surface of the paper feed guide plate and a manual connection joining the upper part of the paper feed guide plate. An upper part of a front cover having a section is attached to a front part of the lower frame so as to be vertically rotatable so as to rotate upward from an installation position, and the upper frame is interfered with by the front cover rotated upward. Kou Watari,
The front chrysanthemum front cover is provided with a locking piece that elastically engages with the lower frame or a mounting portion of the lower frame to lock the front cover with the lower frame.

Therefore, the locking piece is usually engaged with the lower frame or the mounting portion of the lower frame to stabilize the front cover. During the jam treatment between the paper feed guide plate and the front cover, the front cover is rotated upwards to separate from the paper feed guide plate, but the manual cover interferes with the interference part of the upper frame, so the front cover is The upward rotation operation is allowed only when the upper frame is rotated upward. Therefore, when the upper frame is closed, the interference portion presses the front cover in the closing direction, thereby preventing an erroneous operation of driving the front cover in the open state.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 5. Reference numeral 1 denotes a main body, which is composed of a lower frame 2 and an upper frame 3 which are rotatably connected by a support shaft 4, and a mounting plate 6 for mounting a large number of sheets 5 on the lower frame 2. The feeding cassette 8 biased upward by the spring 7, the pick up roller 9 facing the front upper part of the paper feeding cassette 4 and the circumference of the picking up roller 9 rising upward from the front edge of the paper feeding cassette. A paper feed guide plate 11 having a curved surface 10 that curves rearward, and feed rollers 12, 13, 14, 15, 16, 17 along the paper feed guide plate 11,
Pinch rollers 18, 19, 20 are provided. Further, the lower frame 2 is provided with a photoconductor 21, a developing section 22, a transfer charger 23 as a transfer section, and a fixing roller 24 as a fixing section. The upper frame 3 is provided with a charging charger 25, a light source unit 26, and a pinch roller 27 facing the feed roller 13.

Next, a detector 28 that interferes with a part 3a of the upper frame 3 is attached to the lower frame 2. Further, a paper discharge path 29 and a paper receiver 30 are formed in the upper frame 2. In addition, a front cover 31 is provided on the front surface of the lower frame 2.
Is provided. The front cover 31 is made of an elastic synthetic resin, and has a guide surface 32 that faces the curved surface 10 of the sheet feed guide plate 11 and a manual portion 33 that joins the upper portion of the sheet feed guide plate 11. Have Then, the paper feed guide plate 11
The protruding pieces 34 bent on both sides of the front cover 31 are rotatably attached to the bending pieces 33a bent on both sides of the front cover 31 by a support shaft 35. Further, a pinch roller 36 that contacts the feed roller 12 is rotatably held on the front cover 31. Further, as shown in FIG. 5, the front cover 31
A locking piece 39 is elastically formed integrally with the lower part of a bearing 38 that supports the support shaft 37 of the feed roller 12. Further, in front of the upper frame 3, there is provided a manual guide plate 40 which is an interference portion that interferes with the upward rotation of the front cover 31.

In such a configuration, in the process of rotating the photoconductor 21 once, a charging layer is formed on the photoconductor 21 by the charging charger 25, and the charging layer is scanned with a laser beam based on a printing signal from the light source 26 to electrostatic latent image. An image is formed, and the electrostatic latent image is developed by the developing unit 22, and the transfer charger 23 transfers the image on the photoconductor 21 to the paper 5 fed from the paper feed cassette 8 along the paper feed guide plate 11. After the transfer, the fixing roller 24 holds the paper 5 to fix the transferred image. The fixed sheet 5 is sent out to the sheet receiver 30 via the discharge path 29.

Then, when the paper 5 is jammed on the upper part of the paper feed guide plate 11, the upper frame 3 is rotated around the support shaft 4 to remove the paper 5. When the paper 5 is jammed at the entrance of the paper feed guide plate 11, as shown in FIG. 4, the upper frame 3 is rotated upward and the manual guide plate 40 is retracted upward, and the bearing
While removing the locking piece 39 from the 38, the front cover 31 is pivoted upward about the support shaft 35, and the paper feed guide plate 11 and the front cover are rotated.
The paper 5 is removed by widening the gap between the guide surface 32 of 31 and the guide surface 32. The state in which the upper frame 3 is rotated upward is detected by the detector 28, and the power supply is cut off by the detection signal of the detector 28. Although the paper 5 is removed and the front cover 31 is returned to the lower position, if the user forgets to return it, the detection signal of the detector 28 continues to be output unless the upper frame 3 is returned to the lower position, so that the urging is prompted. Even if you forget to return the front cover 31 to the lower position, the manual guide plate 40 pushes down the front cover 31 when the frame 3 is rotated downward.
It is possible to avoid an erroneous operation in which the vehicle is driven while rotating upward. Further, in order to position the front cover 31 at the upper position, it is necessary to maintain the upper frame 3 in a state of being rotated upward. Therefore, the detector 28 for detecting the rotating operation of the upper frame 3 is used. The open / closed state of the front cover 31 can be detected. Further, since the locking piece 39 elastically engages with the bearing 38 of the support shaft 37 of the feed roller 12 and presses the pinch roller 36 against the feed roller 12, the followability of the pinch roller 36 with respect to the feed roller 12 can be enhanced. .

As shown in FIG. 6, holes 41 are formed outside the both side edges of the paper 5 on both sides of the paper feed guide plate 11, and hooks 42 engaging with these holes 41 are formed on the front cover 31. The front cover 31 may be formed on both sides and the front cover 31 may be rotated around the engaging portion of the hole 41 and the hook 42 as a fulcrum.

Further, as shown in FIG. 7, the front cover 31 may be provided with a holding portion 44 that supports the plate spring 43 that supports the lower surface of the locking piece 39. As a result, the engaging force between the locking piece 39 and the shaft support 38 can be strengthened, and the locking piece 39 can be reinforced. As shown in FIG. 8, a locking piece that elastically engages with the lower surface of the bearing 38.
Even if the spring 45 is urged by the spring 46 and is rotatably attached to the front cover 31, the same or higher effect can be obtained.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, when the paper feed guide plate is jammed, the front cover is pivoted upward away from the paper feed guide plate, but the manual part is the interference part of the upper frame. Therefore, the front cover is allowed to rotate upward only when the upper frame is rotated upward, so that when the upper frame is closed, the interference portion closes the front cover in the closing direction. It is possible to prevent the erroneous operation of pressing with the front cover open while operating the front cover, and with this, if a detector for detecting the opening / closing operation of the upper frame is provided, this detector can be used. The rotation of the front cover can be detected, which contributes to simplification of the structure.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a vertical sectional side view, and FIG. 2 is a vertical sectional side view showing a state in which an upper frame and a front cover are rotated upward.
The figure shows a partially enlarged vertical side view, FIG. 4 shows a partially enlarged vertical side view showing a state in which the front cover is rotated upward, and FIG. 5 shows an enlarged side view of the front cover. FIG. 8 to FIG. 8 are side views showing a modification by enlarging the front cover, and FIG. 9 is a side view showing a conventional example with a part cut away. 1 ... Main body, 2 ... Lower frame, 3 ... Upper frame, 5 ... Paper, 8 ... Paper feeding cassette, 9 ... Pickup roller, 10 ... Curved surface, 11 ... Paper feeding guide plate, 21 ......
Photoreceptor, 22 ... Developing section, 23 ... Transfer charger (transfer section), 24 ... Fixing roller (fixing section), 31 ... Front cover, 32 ... Guide surface, 33 ... Manual section, 38 ... … Bearing (mounting part of lower frame), 39 …… Locking piece, 40 …… Manual guide plate (interference part), 45 …… Locking piece

Claims (2)

[Claims] 1. A lower frame is provided with a main body in which an upper frame is rotatably connected vertically, and a main body is provided with a photoconductor, a developing unit for developing an electrostatic latent image formed on the photoconductor, and a transfer unit. A sheet feeding cassette provided with a fixing unit for stacking and storing a large number of sheets, a pick-up roller facing the upper side of the sheet feeding side of the sheet feeding cassette, and rising from the edge of the sheet feeding side of the sheet feeding cassette. A paper feed guide plate that curves along the periphery of the pick-up roller and extends toward the developing portion provided in a substantially central portion is provided in the lower frame, and is located outside the paper feed guide plate. A front cover having a guide surface formed to face the curved surface of the paper feed guide plate at a predetermined interval, and a manual portion formed on the upper surface so as to join the upstream portion of the paper feed guide plate. Is provided with the main body of this front cover The front cover is rotatably attached to the lower frame so that the outer side is rotated upward from the installation position with the inner side being a fulcrum, and the front cover is provided outside the fulcrum of the front cover which is rotated upward on the upper frame. An interference part that returns the front cover to the installation position when the upper frame is located at the installation position by abutting on the upper surface on one side is provided, and the front cover is resilient to the lower frame or a mounting part of the lower frame. And a locking piece for locking the front cover to the lower frame by mechanically engaging with the lower frame. 2. The lock piece is formed separately from the front cover, and the lock piece is rotatably attached to the front cover by being biased by a spring. Paper feeding device for the described electrophotographic printer.