JPH0346941A - Manual paper feed device - Google Patents

Abstract

PURPOSE:To prevent multiple feed at the same time by disposing integratedly a thin plate member with the approximately same coefficient of friction as a sheet of record paper at the sliding surface of a raising-up plate coming into contact with the bottom surface of the record paper. CONSTITUTION:A plastic thin plate member 12 with mat-shaped surface of high coefficient of friction is applied to the top surface of the end 3a of a raising-up plate 3 coming into contact with a sheet of paper 10. It is thus possible to eliminate no feed phenomenon for the paper 10 with a wide variety of properties and prevent multiple feed at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to stabilizing feeding of recording paper from a manual paper feeder in an image recording apparatus.

[Conventional technology]

A conventional manual paper feeding device for conveying recording paper will be explained with reference to the sectional view of FIG.

A manual stacker l (hereinafter referred to as a stacker) is fixedly attached to a paper feed casing 9 and is provided with guides 2a and 2b for loading recording paper 10 (hereinafter referred to as a paper) at the extended rear of the stacker. A manual feed stand 2 is integrally provided, and the back flap of the nuclide feed stand 2 is configured to protrude from the outer periphery of the main body 16 so that its upper surface is open. The paper 10 is loaded along the inclined surface 2b of the manual feed table 2 with the front end surface 1a of the stacker 1 as a reference, one end is fixedly attached to the bottom rear of the stacker 1, and the other end is a lifter that acts as an elastic body. A first plate 3 is provided with the paper 10 lifted from the bottom surface by the tip of the plate 3 and fixed to the paper feed housing 9.
The paper 10 is pressed against the roller surface of the paper feed roller 6 from above. The first paper feed roller 6 rotates in the clockwise direction shown by the arrow due to the loaded operation, and one of the top sheets of paper 10 is fed out by the frictional force generated by the pressure contact between the roller 6 and the paper 10. The paper is then conveyed along the paper guide 7 disposed in the paper feed case 9 to the second paper feed roller pair 8.8a. The paper lO is further conveyed to the photoreceptor 20 located in the traveling direction shown by the arrow by the nipping and rotation of the pair of second paper feeding rollers 8, 8a which continuously rotate at a constant speed in the direction shown by the arrow. The motor 18 repeatedly rotates and stops according to the paper feeding timing controlled by the CPU, and this intermittent rotational drive is transmitted to the first paper feed roller, so that the paper lO is kept at a constant distance from the stacker l. They are sent out one by one.

[Problem to be solved by the invention]

Generally, among the paper feeding mechanisms that transport the paper 10, the first paper feeding mechanism is considered to be the most important part. That is, in order to reliably convey the large number of sheets of paper 10 loaded on the stacker 1 one by one, various factors such as the type of paper 10, thickness, surface roughness, curl direction, and the influence of environmental conditions must be taken into account. The material, surface quality, conveyance position, pressure contact force with the paper IO, etc. of the first paper feed roller 6 must be set in consideration of physical properties.

According to the experimental data during the trial production process regarding the conveyance mechanism and the results of the long-run depack test immediately before mass production, although there are some conveyance jams in each mechanism, most of them are due to no-feeding of the paper 10 in the first paper feeding mechanism or Concentrates on problems with multiple feeds. Moreover, these two phenomena occur due to the setting conditions of mechanisms that are contradictory to each other. For example, if the physical properties of the paper IO are kept constant and the pressure force of the paper IO against the first paper feed roller 6 is reduced, no feed will occur and the opposite will occur. If the pressure welding force is increased, a multiple feeding phenomenon will occur.

Therefore, it is said to be extremely difficult to simultaneously satisfy these problematic phenomena for the paper lO having many different characteristic factors as described above. In the case of this device, the contact pressure of the lifting plate 3 is set high in order to suppress the no-feed phenomenon, and the friction coefficient of the sliding surface of the lifting plate 3 having a metal plate surface is as low as 0.1 or less. the said paper 10 between
The last two to three sheets of paper to be conveyed, or sometimes about 20 sheets, may be fed multiple times due to slipping.

The no-feed phenomenon is considered to be a serious defect in the device because it involves loss of recording opportunity and automatic stop of the paper feeding device, and to prevent this, the pressure applied to the first paper feeding roller 6 is usually set to be high. are doing. On the other hand, the pressing force of the lifting plate is adjusted to prevent the occurrence of multiple feeds as much as possible. In general, this pressure contact force has a very small tolerance with respect to the set value, so it takes a lot of man-hours to adjust it, and a detonation test for confirmation has the drawback of requiring a large amount of cost and man-hours. It is an object of the present invention to provide a manual paper feeding device which solves the above problems and eliminates the no-feed phenomenon even for the paper 10 having many different physical properties, and prevents multiple feeding at the same time.

[Means to solve the problem]

The purpose of this is to use a manual paper feeder in which a large number of recording sheets loaded in a stacker are transported by a first paper feed roller that is driven by a motor. A lifting board lifts the paper from below so that the uppermost surface of the recording paper on which a large number of sheets are mounted is brought into pressure contact with the first paper feed roller located at a fixed position with respect to the paper feed casing. The sheet is intermittently conveyed one sheet at a time to the downstream sheet feeding roller by driving the sheet feeding roller repeatedly rotating and stopping, and the lifting plate contacts the lowermost surface of the recording sheet. This is achieved by a manual paper feeding device characterized in that a thin plate member having a friction coefficient equal to or equal to that of the paper is integrally disposed on a surface thereof to convey the recording paper.

〔Example〕

FIG. 1(a) is a side sectional view of a mechanism in which a thin plate member is arranged on a lifting plate according to an embodiment of the present invention, FIG. 1(b) is a side sectional view showing the structure of the thin plate member, and FIG. 3(a) and a side sectional view of the manual paper feeder of FIG.

This will be explained with reference to a side view of the temporary lifting mechanism shown in (b). FIG. 4 is a side view showing a state in which the manual feed tray is housed on the outer periphery of the main body. However, the present invention is not limited to this example. Items that have the same functions as conventional items are represented by the same symbols.

To explain in detail the paper feed conveyance mechanism of the manual paper feeder according to the present invention, the stacker l is fixedly disposed on both sides of the paper feed case 9; The rear end 1 of the stacker 1 is mounted so as to abut against each other.
The manual feed tray 2 extending rearward with the boundary b is connected to the paper feed casing 9.
The sliding surfaces of the stacker 1 and the sheets 10 are configured so that there is no step between them. The manual feed table 2 has a guide 2a and an inclined surface 2b on both sides, and when loading the paper 10, the paper is inserted along the inclined surface, aligned with the abutment surface 1a of the stacker, and then loaded. .

The lifting plate 3 is fixedly attached by screws 4a to a lifting plate shaft 4 that fits into bearings provided on both sides of the paper feed casing 9, and the shaft 4 is rotatable. It protrudes from the bottom of the stacker and comes into contact with the lower surface of the paper 10. A lifting plate spring 5 is hung on the other end 3b, and one end of the lifting plate spring 5 is hung on the paper feed casing 9, so that the lifting plate is moved in the direction shown by the arrow. The upper surface of the paper 10 is rotated and the upper surface of the paper 10 is placed on the surface of the first paper feed roller 6 by the biasing force of the spring 5, so that the lifting plate tip 3a acts to lift the paper 10 mounted thereon from the lower surface. Welded at a pressure of The first paper feed roller 6 is fixedly attached to a shaft 6a that fits into a bearing provided on the side surface of the paper feed casing 9, and is linked to the rotational drive of the motor 18 to feed the paper 10.
It is located in the center about 10 mm behind the tip of the. The first paper feed roller 6 is constituted by a cylindrical rubber roller whose surface is provided with fine sawtooth steps in the direction of rotation on the circumference in order to have a large coefficient of friction. Rotates according to paper feeding timing controlled by the CPU-U.

Since the drive that repeats stopping is transmitted by the motor I8, the first paper feed roller is also driven to rotate intermittently, and the paper IO loaded in large numbers is sequentially separated one by one and sent out at regular intervals. It is. At this time, the number of rotations of the roller 6 is relatively high at 160 rpm, and the number of rotations of the roller 6 is relatively high.
In order to make this paper feed transportation more stable and reliable, the lifting plate 3 repeatedly presses and releases the paper 10 mounted thereon in synchronization with the rotation of the first paper feed row 26. ing. That is, its operation is shown in Figures 3 (a) and (b).
) as shown in the side view of the rear end 3b of the lifting plate 3.
The other end of the cam lever spring 5 is hung on the bent portion of the cam lever 13, and the lower end of the cam lever 13, which is rotatable about the pivot shaft 15, is hooked on the lower end of the cam lever 13. , are in pressure contact with the cam 14 whose phases are matched to synchronize with the stop. When the first paper feed roller 6 is stopped, the cam lever protrusion 13a is located at the lower stage 14b of the cam 14, so the biasing force of the cam lever spring 5 is weak and the pressing force of the lifting plate 3 against the paper 10 is released. and when the cam 14 is in the upper stage, the cam lever 13 is rotated clockwise by this cam stroke,
The tip 3a of the lifting plate 3 also rotates in the same direction via the lever spring 5, and the lever spring is extended to a predetermined pressing force, so that the paper IO is applied to the first paper feed roller 6 with a set pressure. Forced. Therefore, the paper IO is pressed against the first paper feed roller 6 at a set pressure before the rotation starts, and when the roller 6 stops, the pressure contact is released by the lower cam stage 14b. Note that there is no problem even if the lifting plate 3 always presses the sheet 10 against the first paper feed roller 6 with the constant pressure of the spring 5 without repeating the application and release of the set pressure as described above. . The paper lO fed out from the first paper feed roller 6 in this way is transferred to the paper guide 7.
along the multiple feed prevention roller 11. Transported to lla.

The multiple feed prevention roller 11. When the paper 10 is normally fed one by one, the paper 10 passes through the rollers If and lla as it is, but when the paper 10 is repeatedly fed at intervals, the paper 10 passes through the rollers If and lla. The paper IO is transferred to the roller 11. It is detected by the torque limit applied to lla. The roller lla is arranged in such a way that the roller lla is slightly reversed to separate the multi-fed sheets 10 and normally convey only the upper sheet. The multiple feed prevention roller 11. The paper IO that has passed through the second paper feed rollers 8, 8a along the vapor guide 7a
The upper roller 28 is rotated clockwise and the lower roller 8a is rotated counterclockwise, and the paper 10 is conveyed while being pressed against each other so as to sandwich the paper 10, so that the second paper feed roller 8.8a Even when the paper feed roller 6 and the multiple feed prevention roller 11.11a are in operation, the paper lO is conveyed while being pulled and sent to the photoreceptor 20.

Since the rear end of the manual feed table 2 protrudes from the outer periphery of the main body 16, it can be separated from the joint surface with the rear end 1b of the stacker 1 about the pivot shaft 2c as shown in FIG. The main body 16 is folded vertically into the manual feed tray 2.
It is also possible to store it so that it is in contact with the outer peripheral surface of. The series of conveyance mechanisms described above are constructed as a unit in the paper feed casing 9 along with other trays and conveyance mechanisms (not shown), and are fixedly attached to the main body 16. The present invention has the structure of such a manual sheet feeding device, and unlike the conventional method of contacting the metal surface of the lifting plate 3 that contacts the lower surface of the paper 10, as shown in FIGS. 1(a) and 1(b), A plastic thin plate member 12 having a matte surface with a high coefficient of friction is pasted on the upper surface of the lifting plate tip 3a where the lifting plate 3 contacts the paper lO. The thin plate member 12 has a thickness of 0.2 to 0.3
It is a member that has a surface friction coefficient of approximately 2 to 3 times higher than that of a metal surface, and has excellent wear resistance.

The thin plate member 12 has double-sided tape 12a and top paper 1 on the back side.
2b is integrally formed into a sheet-like member, which is punched out into a predetermined shape to form individual members, and when pasting them onto the lifting plate 3, the upper paper 12b may be peeled off and pasted at a predetermined position.

〔Effect of the invention〕

Since the present invention is configured as described above, the no-feed phenomenon can be eliminated even when a large number of sheets of paper 10 loaded on the manual stacker 1 are conveyed at high speed by the first paper feed roller 6 with a simple structure. Needless to say, multiple feeds 6 caused by slipping with the lifting plate 3 can be prevented at the same time, which increases the reliability of the paper feeder and also improves the long run for adjusting and checking the pressure contact force on the paper lO. The savings in pack costs are significant.

[Brief explanation of drawings]

FIG. 1(a) is a side sectional view showing a mechanism of a lifting plate provided with a thin plate member according to an embodiment of the present invention. FIG. 1(b) is a side sectional view showing the structure of the thin plate member. FIG. 2 is a side sectional view of the manual paper feeder. FIGS. 3(a) and 3(b) are side views of the temporary lifting mechanism. FIG. 4 is a side sectional view of the manual feed stand housed on the outer periphery of the main body. FIG. 5 is a side sectional view of a conventional manual paper feeder. ■...Stacker la...Paper abutment surface 1
b... Rear end of stacker 2... Manual feed stand 2a...
Manual feed base guide 2b...Manual feed base inclined surface 2c...
Manual feed table rotation support shaft 3...Lifting plate 3a...Lifting plate tip 3b...Lifting plate rear end 4...Lifting plate shaft 4a...Temporary lifting screw 5...Lifting plate Spring 6・
...First paper feed roller 6a...First paper feed roller shaft 7...First paper guide 7a...Second paper guide 8.8a...Second paper feed roller 9...Paper feed Housing 10...Recording paper (paper) 11, lla...Multiple feed prevention roller 12...Thin plate member 12a...Double-sided tape 12b...
Top page 13...Cam lever 13a...Cam lever protrusion

Claims (1)

[Claims] In a manual paper feed device in which a large number of recording sheets loaded in a stacker are conveyed by a first paper feed roller rotated by a motor, a lifting plate is rotated by the biasing force of a spring disposed in a paper feed housing. Lift the paper from below so that the uppermost surface of a large number of recording sheets is brought into pressure contact with the first paper feed roller, which is located at a fixed position with respect to the paper feed housing, and press the first paper feed roller. The sheet is intermittently conveyed one sheet at a time to the paper feed roller side on the downstream side by a drive that repeats rotation and stopping, and a sliding surface of the lifting plate that is in contact with the bottom surface of the recording sheet is A manual sheet feeding device characterized in that the recording paper is conveyed by integrally disposing a thin plate member having a friction coefficient around the same as that of the paper.