JPH05173263A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate such troublesomeness as a press plate is opened and closed after movement of a document table is stopped, in a document movement type image forming device. CONSTITUTION:A press plate rotary shaft is pivotally supported to a document table 6 and lever members 18 pivotally mounted respectively on a lever member 19 and a shaft 22 are engaged together by means of a notch. A cam follower 17 is arranged to the tip of the lever member 18 and a cam part 24 fixed to a body and the cam follower 17 are engaged together. Through reciprocation of the document table 6, the cam follower 17 is progressed, in order, to cam grooves 25, 26, 28, 30, 31, and 25. A check claw 27 prohibits the progress of the cam follower 17, in order, to 28 and 26, and a regulating member 32 is designed such that it is prevented from reversing in the cam groove 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automatic opening and closing of a pressure plate in an image forming apparatus such as a copying machine of a platen moving type.

[0002]

2. Description of the Related Art Conventionally, when setting a document on a copying machine or the like, a user manually opens the pressure plate, sets the document, then closes the pressure plate to perform a copying operation, and when the copying of the document is completed, the plate is manually pressed. I opened it up and took out the original.

[0003]

When a document is moved continuously in a machine of a platen moving type, the above document replacement work must be started after the operation is stopped. Further, even if the manuscript pocket is attached to the pressure plate, the manuscript replacement work is complicated.

The present invention has been made in view of the above problems, and an object thereof is to provide an apparatus having a simple structure and capable of performing a copying operation without a user manually opening and closing the pressure plate.

[0005]

A first aspect of the present invention is a movable document table, a pressure plate that is rotatably supported by the document table and holds a document, and a pressure plate is opened / closed as the document table moves. The image forming apparatus is provided with an opening / closing device that operates.

A second aspect of the present invention is characterized in that the opening / closing device has a regulating member which engages with the pressure plate and regulates the movement of the pressure plate, and the regulating member is fixed to the main body of the apparatus. 1
The image forming apparatus according to the invention.

According to a third aspect of the present invention, the image forming apparatus according to the first or second aspect is characterized in that the pressure plate is opened and closed by the movement of the document table moved by the means for driving the document table. It is a device.

According to a fourth aspect of the present invention, the image forming method according to any one of the first to third aspects is characterized in that the driving direction of the platen and the opening / closing direction of the pressure plate are in the same order. It is a device.

[0009]

EXAMPLES The present invention will be described below with reference to specific examples.

[First Embodiment] FIG. 1 is a longitudinal sectional view of a copying machine according to an embodiment of the present invention. The sheet 2 stacked in the sheet feeding cassette 1 is sent out by the sheet feeding roller 3, conveyed by the slip roller 4, and reaches the registration roller 5. The registration roller 5 makes the sheet 2 stand by for a certain period of time, and conveys the sheet 2 in synchronism with document exposure. The document table 6 is configured to be movable in the left-right direction.
The original document placed on it is illuminated by an illumination lamp 7 and projected onto a photosensitive drum 9 through a self-occ lens 8. Around the photosensitive drum 9, known charging means, developing means, and cleaning means (not shown) are provided, and after the latent image is formed, transfer is performed on the sheet 2 conveyed from the resist roller 5 by known transfer means. The transferred sheet 2 is guided by the fixing inlet guide 11 via the conveying unit 10 and is conveyed to the fixing device 12. The sheet 2 fixed by the fixing device 12 passes through the paper discharge roller 13 and is discharged to the outside of the machine.

FIG. 2 is a rear view of FIG. 1 showing a drive system of a copying machine which is a specific example of the present invention. A part of the document table 6 for placing the document has a rack 6a, and the rack 6a
Engages with the pinion gear 14 to transmit drive. The pinion gear 14 is driven by the main motor 15 via a plurality of gears.

Further, by providing a clutch mechanism (not shown) in the intermediate path from the output gear fixed to the main motor 15 to the pinion gear 14, the pinion gear 14 can be rotated normally or reversely. .. Therefore,
The document table 6 can be moved rightward or leftward by rotating the pinion gear 14.

The original table 6 is provided with cams A, B and C,
Document position detecting means a and b operated by these cams are provided on the main body side. The detection means a, b and the cam A,
Arms d and e are provided between B and C, respectively. These arms d and e are in the form of arms pivotally attached to the main body by a pin 41, the middle of the arms are in contact with the actuators attached to the detection means a and b, and at the tips of the arms are roller followers that engage with cams A, B and C. 42 are provided. Therefore, the document table 6
When the cams A, B, and C move due to the movement of the roller, the roller follower 42 is pushed, and the arms d and e rotate around the pin 41 and move down to operate the detection means a and b. When the copy button is turned on while the rack 6a and the pinion gear 14 are in mesh with each other, the original table 6 turns on the original position detecting means a with the cam A and the original position detecting means b with the cam B from the state of FIG. After moving to the right so as to be in the state, it is synchronized with the fed sheet 2. At this time, by switching a clutch (not shown), the pinion gear 14 reversely rotates, and the document table 6 moves leftward to start exposure of the document. When the document C is exposed and the cam C turns on the document position detecting means a,
The original platen 6 is reversed by a clutch (not shown), moves rightward again, and returns to the state of FIG. 2 to stop.

Next, the pressure plate 1 for pressing the document on the document table 6
The switchgear 6 will be described.

A pressure plate rotating shaft 22 fixed to the edge of the pressure plate 16.
Is rotatably supported on the document table 6. As shown in FIGS. 3 and 4, one end of the pressure plate rotating shaft 22 is provided with a lever member (a) 18 which is rotatable with respect to the shaft 22. A lever member (b) 19 fixed by a shaft 22 and a spring pin 23 is provided. The tip end member of the lever member (a) 18 is the cam follower 17, and the cam follower 17 moves by being guided by the cam portion 24 fixed to the main body (details will be described later). Considering this, the angle with respect to the pressure plate rotating shaft 22 changes with the movement of the document table 6. The lever member (b) 19 is engaged with a V groove 18a of the lever member (a) 18 (a V groove perpendicular to the lever member (a) 18) via a notch 20 pressed by a spring 21. Interlocking with the movement of the cam follower 17, the lever member (a) 18 and the lever member (b) 19 integrally swing to rotate the pressure plate 16. That is, when the cam follower 17 is raised, the lever plate (a) 18 and the lever member (b) 19 are engaged with the notch 20 and the pressure plate rotating shaft 22 is rotated in the direction in which the pressure plate 16 moves away from the document table 6 to press the pressure plate. 16 opens, and when the cam follower 17 descends, the pressure plate 16 closes contrary to the above.

If the pressure plate 16 is forcibly closed by hand when the pressure plate 16 is in the open state, the pressure plate rotating shaft 22 rotates and the V groove 18a of the lever member (a) 18 pushes the notch 20 and the notch 20 springs. By compressing 21 (see FIG. 4), the lever member (a) 18 is disengaged, and the pressure plate 16 can be manually opened and closed at any position.

The movements of the cam portion 24 and the cam follower 17 fixed to the main body will be described. The cam portion 24 is the pressure plate 1.
It is a regulating member that regulates the movement of No. 6.

When the document table 6 of FIG. 1 is in the original position and is moved to the left copying start position, the cam follower 17 is engaged with the cam groove 24 of the cam groove 24.
To reach the flat portion 26. Cam follower 1 at this time
By raising 7, the pressure plate 16 is opened at a predetermined angle, and the original can be set. When a copy button (not shown) is turned on in this state, the cam follower 17 is pivotally attached to the cam portion 24 by a pin 29, gets over the non-return pawl 27 biased by the spring force in the clockwise direction, reaches the flat portion 28, and then is conveyed. The sheet 2 is instantaneously stopped to synchronize with the sheet 2. Thereafter, the document table 6 is reversed and moves rightward, so that the cam follower 17 is guided by the check claw 27 and slides down the inclined portion 30. The check claw 27 is made of resin and is rotatable about a pin 29. The rear part of the check claw 27 is shaped like a leaf spring 27a. The pin 27b planted in the cam portion 24 prevents the check claw 27 from rotating. Spring force is applied.

When the cam follower 17 slides down the inclined portion 30, the pressure plate 16 is closed and the original is pressed against the original table 6. When the cam follower 17 reaches the flat portion 31, the illumination lamp 7 is turned on, and the exposure of the original document on the already exposed photosensitive drum 9 is started. The cam follower 17 moves to the right of the document table 6 and the flat portion 3
1 is moved to the right, and document exposure is continued. The cam follower 17 that has moved to the right on the flat portion 31 further moves to the right while pushing up the switching cam member 32 pivotally attached to the cam portion 24 by the pin 33. The switching cam member 32, like the check claw 27, has a resin-integrated shape and is rotatable about a pin 33, and its rear end is a leaf spring 32.
In the shape of a, the leaf spring 32 is stopped by a pin 32b implanted in the cam portion 24, and the switching cam member 32 is biased clockwise by a spring force so that the cam follower 17 can move smoothly. There is. When the document exposure is completed and the document table 6 is reversed and moves leftward, the cam follower 17 goes up the inclined portion 25 and stops at the flat portion 26. Along with this, cam follower 1
7 rises, and the pressure plate 16 opens by rotating the pressure plate 16 around the pressure plate rotation shaft 22. At this time, since the pressure plate 16 is in the open state, it is possible to replace or set the original document as it is. In the case of the present embodiment, the process cartridge system in which the photosensitive drum, the developing means and the cleaning means are integrated is adopted, and when the process cartridge is replaced or the jam processing is performed, the document table 6 is set to the left end. It is configured to move and open the upper side of the machine in an alligator shape. It is a so-called clam shell type.

When the original table 6 is manually moved to the left end, it is guided by the cam member 35 from the flat portion 28, goes down the inclined portion 34, and reaches the flat portion 36. When the document table 6 is moved to the right from this state, the cam follower 17 moves the flat portions 37, 3
It smoothly returns to the state of Fig. 1 through 1.

As described above, it is possible to set a document and perform a copying operation without manually opening and closing the pressure plate by the regulating member that engages with the pressure plate as the platen moves.

[Other Embodiments] As shown in FIG. 5, when the platen 6 is biased by the spring member 43 in the direction of opening the platen in advance and the document table 6 moves rightward to perform image exposure, as shown in FIG. The height of the upper part of the pressure plate 16 is regulated by the roll 39 rotatably fixed to the main body side.

For the spring member 43, any means such as a compression spring, a tension spring, a torsion spring, a leaf spring or the like may be selected as long as it can be biased in the direction of opening the pressure plate 16.

Although the roll 39 is rotatable and absorbs the impact at the time of contact, the pressure plate 16 may be pressed by a non-rotating member.

As another example, as shown in FIGS. 7 and 8, one end of a link member 38 having a guide groove 38a in the longitudinal direction is pivotally attached to the pressure plate 16, and a pin-shaped stopping member fixed to the guide groove 38a is provided. 40 is fitted. When the document table 6 moves to the right from the state of FIG. 7, the end portion of the guide groove 38a hits the stopper member 40, so that the pressure plate 16 held in the open state is held.
Since the position of the stop member 40 moves from the end portion of the guide groove 38a to the middle portion, the position is closed, and the state of FIG. In this case, it is possible to change the shape of the link member depending on the moving distance of the document table and the opening angle of the pressure plate, and it is also possible to use another link mechanism having a plurality of links.

In the embodiment, the opening / closing device of the pressure plate is driven by the movement of the platen as a driving source. It is possible to open and close the pressure plate by rotating the pressure plate rotating shaft by controlling the driving source.

[0027]

As described above, since the present invention is provided with the opening / closing device for opening and closing the pressure plate as the platen moves, the user does not need to wait for the platen to operate the pressure plate. There is an effect that the manuscript can be removed by simply waiting for the document to be automatically opened and then set, and the operation becomes easy.

If a regulating member that engages with the pressure plate is provided on the apparatus main body side, the pressure plate itself, a cam follower, a link, or the like may be used as the driven member on the pressure plate side, so that the operation required for achieving the above-mentioned effect is simplified. ..

When the platen opening / closing device is driven by moving the platen, a separate drive source is not required.

If the driving direction of the platen and the opening / closing direction of the pressure plate are in the same order, the opening / closing device can be almost grouped on the side of the platen, and even if the platen is manually opened / closed, the opening / closing device hinders the operation. Don't

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a rear view of FIG.

FIG. 3 is a horizontal sectional view showing the structure of a pressure plate.

FIG. 4 is a horizontal sectional view showing the operation of FIG.

FIG. 5 is a side view of another embodiment.

FIG. 6 is a side view showing the operation of FIG.

FIG. 7 is a side view of still another embodiment.

8 is a side view showing the operation of FIG. 7. FIG.

[Explanation of symbols]

 6 platen 16 pressure plate 17 cam follower 24 cam section

Claims (4)

[Claims] 1. An image comprising a movable manuscript table, a pressure plate rotatably supported by the manuscript table to hold a manuscript, and an opening / closing device for opening and closing the pressure plate as the manuscript table moves. Forming equipment. 2. The image according to claim 1, wherein the opening / closing device has a regulating member that engages with the pressure plate and regulates the movement of the pressure plate, and the regulating member is fixed to the main body of the device. Forming equipment. 3. The image forming apparatus according to claim 1, wherein the pressure plate is opened / closed by the movement of the document table which is moved by the means for driving the document table. 4. The image forming apparatus according to claim 1, wherein the driving direction of the document table and the opening / closing direction of the pressure plate are in the same order.