JP3305402B2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to printing, copying, transferring,
The present invention can be applied to printers, copiers, facsimile machines, electronic blackboards, printing machines, and the like that perform printing and the like. More specifically, in such a printer or the like, the present invention relates to a sheet feeding device in which a sheet feeding cassette is inserted, a sheet feeding roller is rotated, and sheets in the sheet feeding cassette are sequentially fed from the top.

[0002]

2. Description of the Related Art Conventionally, for example, in a printer, when a paper feed cassette 1 shown in FIG. 15 is inserted into a printer main body (not shown) from the direction of arrow D shown in FIG. 16, a cam member 2 provided integrally with the cassette main body 1A. The displacement member 4 is displaced in the direction indicated by the arrow in FIG.
The lifter 6 is turned in the direction of the arrow against the first urging member 7, and the lifter 6 pushes up the sheet feeding plate in the sheet feeding cassette 1. Then, the uppermost sheet on the sheet feeding plate is pressed against the sheet feeding roller, and the sheet is fed in order from the top by the rotation of the sheet feeding roller.

[0003]

However, in the conventional printer, the paper feed cassette 1 is
A is made of a cheap and relatively strong material in a box shape with the upper side opened, and the cam member 2 is integrally formed of the same material. Therefore, there are the following problems. If the paper cassette is made of a relatively inexpensive and relatively strong material in order to reduce the cost of the paper cassette, the slidability of the cam member is poor. If the paper feed cassette is made of a material having good slidability, such as polyacetal, for example, in order to reduce the operation force, the cost will increase. When the cam member breaks, the entire cassette must be replaced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper feeder which uses a paper feed cassette which is inexpensive, has good operability, and can be replaced only with a cam member.

[0005]

Accordingly, the present invention provides
For example, as shown in the illustrated embodiment below,
0 is inserted, and the cam member 31 of the sheet cassette 20 pushes and rotates the rotation lever 45 as a displacement member .
And the displacement is transmitted to the lifter 40 via a first biasing member such as a lift spring 48, and the lifter 4
0 is rotated against a second biasing member such as a return spring 44, the sheet S in the sheet cassette 20 is lifted by the lifter 40, and the sheet S is rotated from above by the rotation of the sheet feeding roller 19. In the sheet feeding device 18 that sequentially feeds the sheet, the cam member 31 is made of a material having good slidability.
The 0 of the cassette body 20A is formed separately, the cassette
The paper feed cassette 20 is provided on the side wall 20f of the main body 20A.
A plurality of mounting positions such as a mounting hole 20h for selectively mounting the cam member 31 in accordance with the type of the sheet S such as a sheet size and a weight in the sheet feeding cassette 20 in the mounting / removing direction. It is characterized by being provided.

According to a second aspect of the present invention, as shown in the following embodiment, for example, in the sheet feeding cassette 18 according to the first aspect, both side walls 20 of the cassette main body 20A are provided.
f, a plurality of mounting holes are provided, and a plurality of mounting positions are provided.
The cam member is screwed into one of the mounting holes 20h with a screw 32.
31 is selectively attached .

According to a third aspect of the present invention, as shown in the following embodiment, for example, the sheet feeding device 18 according to the second aspect is provided.
In the above, for example, a reflection sensor 50 or a push switch 51 for detecting the type of sheet in the sheet cassette 20 is used.
Sheet detecting means, a cam member detecting means such as a push switch 52 for detecting the mounting position of the cam member 31, and a warning means for issuing a warning by comparing the detection results of the detecting means. It is characterized by becoming.

[0008]

According to the present invention, the mounting position is selected in accordance with the type of the sheet S in the sheet feeding cassette 20, and the cam member 3 is selected.
1 is attached to the side wall portion 20f of the cassette body 20A , and when the sheet cassette 20 is inserted, the cam member 31
Is displaced by pushing and rotating the turning lever 45, which is transmitted to the lifter 40 via the first urging member, and the lifter 40 is turned against the second urging member, The sheet S in the sheet cassette 20 is lifted by the lifter 40. Then, the sheet S is sent out from the top by rotating the sheet feeding roller 19. Thus, the cam member 31
When is damaged, only the cam member 31 is replaced.

According to the second aspect of the present invention, the cassette body is provided.
A plurality of mounting holes 20h provided on both side wall portions 20f of 20A are provided.
A plurality of mounting positions are provided, and one of the mounting holes 20h has a screw 3
2, the cam member 31 is selectively attached.

According to the third aspect of the present invention, when the sheet cassette is inserted, the type of the sheet in the sheet cassette is detected by the sheet detecting means, and the cam member is moved.
1 is detected by the cam member detecting means. And
When the type of the sheet S does not match the mounting position of the cam member 31 based on the comparison of the detection results of the detection units, a warning is issued by the warning unit.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 13 shows a schematic configuration of an internal mechanism of a laser printer having a paper feeding device according to an embodiment of the present invention.

The reference numeral 10 in the drawing denotes a printer main body. The printer body 10 includes an upper body 10a and a lower body 1
0b, and the upper main body 10a can be freely opened and closed about the rotation fulcrum 11 on the lower main body 10b. In the printer main body 10, a belt-shaped photoconductor 12 is provided substantially at the center.

Around the photoreceptor 12, a charging device 13, a developing device 14, a transfer device 1 are arranged in a driving direction indicated by an arrow in FIG.
5. Arrange the cleaning device 16. Those chargers 13
On the upper side of the cleaning unit 16 and the optical writing unit 17, on the lower side of the transfer unit 15 and the photoconductor 12,
The paper feeding device 18 according to the present invention is arranged. The sheet feeding device 18 includes a sheet feeding roller 19 and a sheet feeding cassette 20.

When recording is performed using the illustrated laser printer, the sheet S stored in the sheet cassette 20 is fed in the direction of arrow A by rotating the sheet feeding roller 19, and the sheet S is moved between the registration roller pair 21. And stop. Thereafter, the sheet S is conveyed to the lower side of the photoconductor 12 at a timing by the registration roller pair 21.

The photosensitive member 12 is driven in a clockwise direction as indicated by an arrow. At this time, the surface of the photosensitive member 12 is uniformly charged by a charger 13 and is irradiated with a laser beam from an optical writer 17.
2 to form an electrostatic latent image. Then, when passing through the position of the developing device 14, the electrostatic latent image is visualized by toner, and the visible image is conveyed to the lower side of the photoconductor 12 by the sheet S.
Is transferred onto the upper surface of the substrate by the transfer device 15.

After the image transfer, the sheet S is conveyed to the fixing device 24, and the transferred image on the sheet S is fixed by the fixing device 24. The sheet S that has exited the fixing device 24 is further conveyed by a pair of paper discharge rollers 25 and selectively discharged as appropriate in the direction of arrow B or C in the figure.

On the other hand, the photoreceptor 12 after image transfer removes residual toner by a cleaning device 16 and then removes the residual toner.
At 6, the charge is removed.

The lower main body 10b has a mounting port 30a on the right side in the figure, from which the paper feed cassette 20 can be detachably attached to the paper feed apparatus 18.

As shown in FIG. 3, the cassette body 20A is formed in a box shape having an upper side opened with an inexpensive and relatively strong material, and the left side in FIG. The right side in the figure is the mounting-side rear end 20b.
At the bottom plate portion 20c of the cassette body 20A, a mounting end 2 is provided.
A light path window hole 20e is provided near 0a, and a rear end 20b on the mounting side is provided.
A lifter window hole 20d is provided nearer. As shown in FIG. 4, recesses 20g are provided in the side walls 20f of the cassette body 20A in a laterally long position near the mounting-side tip 20a.
h is provided in plurality. The mounting holes 20h are appropriately arranged at predetermined intervals in the length direction of the recess 20g in accordance with the type of sheet size stored in the sheet cassette 20. For example, the mounting hole at the right end in the drawing is of a sheet size B5 length. As shown in FIG. 3, the cam member 31 is attached to one of the attachment holes 20h with a screw 32.

As shown in FIG. 5, the cam member 31 is formed in a block shape, and is formed to be slightly laterally long with a material having good slidability such as polyacetal, and a concave portion 31a is provided on one side to press against the outer edge. The portion 31c is provided in a frame shape, and is provided substantially at the center of the inside through a screw hole 31b. The pressing portion 31c is inclined forward and upward in the left direction in the figure. On the right side of the cam member 31 in the figure, a plurality of ribs 31d and 31e are provided in parallel in a direction perpendicular to the length direction thereof.

The bottom plate 20c in the cassette body 20A
As shown in FIG. 6, a paper feed plate 35, a pair of side fences 36, and an end fence 37 are provided on the upper side. The sheet supply plate 35 is provided so as to cover the lifter window hole 20d, and the distal end side is provided so as to be vertically rotatable with the base end as a fulcrum. The pair of side fences 36 are provided movably in a direction E perpendicular to the sheet feeding direction indicated by an arrow F, and a protrusion 36 a is provided at an upper end of one side fence 36. The end fence 37 is provided movably in the F direction.

On the other hand, in the lower body 10b shown in FIG.
A lifter 40 is provided near the mounting opening 30a of the paper cassette 20 as shown in FIG. The lifter 40 has a lift arm 42 attached to a rotating shaft 41 supported by a side plate (not shown).
And the lift lever 43 are fixedly provided. The lift arm 42 has an arc-shaped pressing portion 42 a formed at the end, and the other end is fixed to the center of the rotating shaft 41. The lower ends of the lift levers 43 are fixed to both ends of the rotation shaft 41, and the lift lever 43 is rotatable with the lift arm 42 via the rotation shaft 41. Then, one end of a return spring 44, which is a second biasing member, is hung on the upper end of the lift lever 43 . The other end of the return spring 44 is connected to the lower body 10.
Hook in b.

A rotating lever 45, which is a displacement member, is provided at a predetermined interval between the lifter 40 and the inside of the lower body 10b. The rotating lever 45 has a lower end rotatably attached to a rotating shaft 46 supported by a side plate (not shown). The rotating lever 45 is provided with an abutting member 47. The abutting member 47 is formed by bending a lower end 47a at a right angle to the lifter 40 side.

Between the rotation lever 45 and the lift lever 43, one end is hooked on the lift lever 43, and the other end is hooked on the rotation lever 45, so that the lift as the first urging member is lifted. Hang the spring 48. The urging force of the lift spring 48 is weaker than the urging force of the return spring 44 when the sheet cassette 20 is not attached. And the return spring 44
With the urging force of the above, the lifter 40 is rotationally urged clockwise, the lift arm 42 is depressed, the pressing portion 42a is pressed against the bottom plate portion 10c of the lower main body 10b, and the lift lever 43 is held in the upright position. The lower end 47a of the abutting member 47 of the rotating lever 45 is pressed against the bottom plate portion 10c to rotate the rotating lever 45.
In the standing position.

A sheet detecting means for detecting a sheet size is provided in the lower main body 10b. The sheet detecting means includes a reflection sensor 50 and a push switch 5 shown in FIG.
It is composed of 1. A plurality of the push switches 51 are arranged on the one side fence 36 in the moving direction. Further, the cam member 3 is provided in the lower main body 10b.
1 is provided. The cam member detecting means is constituted by a push switch 52 as shown in FIG. 8, and is arranged side by side in the figure. Then, as shown in FIG. 9, the sheet detecting means and the cam member detecting means are electrically connected to the electric control means, and the electric control means is provided with a warning means for issuing a warning by voice or display. Connection.

For example, when a B5 vertical sheet size is used, as shown in FIG. 6, a B5 size sheet S is placed on the paper feed plate 35 in the F direction and stored in the cassette body 20A. The pair of side fences 36
The sheet S the end fence 37 is moved, respectively it with
Regulate movement. Then, the mounting hole 20 for B5 vertical
g (shown in FIG. 4), a screw 32 is attached through the screw hole 31 b of the cam member 31, and the cam member 3 is attached to the sheet cassette 20.
Fix 1

[0027] Then, inserted through mounting opening 30a of the cassette body 20A in FIG. 7 from an arrow G direction. Then
When the pressing portion 31c of the cam member 31 of the paper feed cassette 20 hits against the abutting member 47 of the rotating lever 45, and further pushes the paper feeding cassette 20, the rotating lever 45
Rotates counterclockwise against the lift spring 48,
Tilt as shown in FIG. As a result, the urging force of the lift spring 48 becomes stronger than the urging force of the return spring 44. Then, the urging force of the lift spring 48 rotates and lifts the lift lever 43 counterclockwise,
The lift arm 42 also rotates to gradually lift the pressing portion 42a through the lift window hole 20d (shown in FIG. 3). Then, the pressing portion 42a is gently applied to the rear surface of the paper feed plate 35 to push up the paper feed plate 35.

However, as shown in FIG.
The sheet S stacked thereon is pressed against the sheet feeding roller 19 with an appropriate pressing force. After the sheet cassette 20 is attached, the rotating lever 45 is pressed by the cam member 31 to the rotating position, and the lifter 40 is held in the pushed up state.

By the way, as described above, the sheet feeding cassette 2
When 0 is inserted, as shown in FIG. 10, the sheet feeding cassette 20 is detected by detecting means (not shown).
When one of the push switches 51 is pressed by the convex portion 36a of the side fence 36 to detect the sheet width, and when the sheet S interrupts the optical path, the reflection sensor 50 detects the sheet length and the sheet size in the sheet cassette 20. Detect and store it. On the other hand, when the push button 52 is pressed by the rib 31e of the cam member 31, the mounting position of the cam member 31 is detected and stored. Then, it is determined whether or not the stored sheet size matches the stored mounting position of the cam member 31.
If they do not match, a warning is issued by the warning means to inform the user and correct the error. And the paper feed roller 19
An appropriate pressing force for pressing the sheet S against the sheet is surely obtained.

Thereafter, when changing the sheet size from B5 length to, for example, A3 size, the sheet cassette 20 is pulled out to the right in FIG. 1 and removed. At this time, since the pressing of the rotating lever 45 by the cam member 31 is released, the return spring 44 eventually becomes stronger than the urging force of the lift spring 48, and the return spring 44
And the rotating lever 45 by the urging force of the lift spring 48.
Is turned from the turning position to the original standing position. Further, the lift lever 43 also rotates to return to the original standing position indicated by the chain line, and the lift arm 42 also rotates together to return to the original retracted position.

Then, the sheet S of B5 length is taken out of the removed sheet feeding cassette 20 and is replaced with an A3 size sheet. At this time, the cam member 31 is simultaneously changed to the mounting hole 20h (shown in FIG. 4) of the A3 size sheet.

When the sheet feeding cassette 20 is inserted into the sheet feeding device main body 30 again, the inclination angle of the rotating lever 45 is increased to increase the urging force of the lift spring 48 as compared with the case of B5 horizontal. And A3 size sheet S
Is pressed against the paper feed roller 19 with an appropriate pressing force.

By the way, for example, if the cam member 31 is fixed and the pressing force is set according to the A3 size,
Since the sheet weight applied to the sheet feeding plate 35 in the case of the 5-size vertical or the A4-size vertical is small, as shown in FIG. 12, when the number of stacked sheets increases to 400 sheets, the sheet pressing force exceeds an appropriate range, and as a result, Then, the pressing force against the sheet feeding roller 19 becomes too large, and the sheet S is double fed. However, when the mounting position of the cam member 31 is changed as described above, the urging force of the lift spring 48 changes accordingly, and therefore, as shown in FIG. The sheet pressing force can be kept in an appropriate range.

In the illustrated embodiment described above, when the sheet cassette 20 is inserted, the rotary lever 45 is rotated to rotate the lifter 40 to the push-up position. Alternatively, a sliding means 55 may be provided, and the lifter 40 may be rotated to the push-up position by sliding the sliding means 55.

[0035]

Therefore, according to the present invention, since the cam member is formed separately from the cassette main body, the paper feed cassette can be formed at low cost, and the operability can be improved. When the cam member is damaged, only the cam member can be replaced and the sheet cassette can be reused, so that the maintenance cost can be reduced.

[0036] In addition, after storing sheets in the paper feed cassette,
Since the mounting position is selected according to the type of the sheet and the cam member is mounted on the cassette body, an appropriate sheet pressing force according to the type of the sheet can be obtained.

According to the third aspect of the present invention, when the sheet cassette is inserted, when the type of sheet and the mounting position of the cam member do not match according to the comparison of the detection results of the sheet detecting means and the cam member detecting means. Since a warning is issued by the warning means, an error can be corrected and an appropriate pressing force of the sheet pressed against the paper feeding roller can be reliably obtained, thereby preventing a paper feeding malfunction such as double feeding or non-feeding. be able to.

[Brief description of the drawings]

FIG. 1 is a state diagram showing a state in which a paper feed cassette is mounted in a paper feed device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation state when the sheet cassette is attached.

FIG. 3 is a perspective view in which the inside of the sheet cassette is omitted.

FIG. 4 is an enlarged perspective view of a part thereof.

FIG. 5 is a perspective view of a cam member attached to the sheet cassette.

FIG. 6 is a perspective view of a part of the inside of the paper feed cassette.

FIG. 7 is a schematic configuration diagram of a sheet feeding device showing a state where the sheet cassette is not attached.

FIG. 8 is an explanatory view of a state of a cam member detecting means provided in the sheet feeding device.

FIG. 9 is a block diagram showing a sheet detecting unit / cam member detecting unit and an electric control unit, and a connection relationship between the electric control unit and the warning unit;

FIG. 10 is a flowchart when the sheet cassette is attached.

FIG. 11 is a graph showing a relationship between a sheet pressing force and a total number of stacked sheets when a cam member is changed according to various sheet sizes of B5 length, A4 length, and A3 length.

FIG. 12 is a graph showing the relationship between the sheet pressing force and the total number of stacked sheets when the cam member is fixed and the sheet pressing force is adjusted to A3 size.

FIG. 13 is a schematic configuration diagram of the entire internal mechanism of a laser printer including the sheet feeding device of the present invention.

FIG. 14 is a schematic configuration diagram showing a main part of a paper feeding device main body side of a paper feeding device according to another embodiment of the present invention.

FIG. 15 is a perspective view of a paper feed cassette used in a conventional paper feed device.

FIG. 16 is a schematic configuration diagram of a sheet feeding device in a state where the sheet cassette is not attached.

[Explanation of symbols]

 18 paper feeder 19 paper feed roller 20 paper feed cassette 20A cassette body20f Side wall 20h Mounting hole (mounting position)  31 Cam member32 screws 40 Lifter  44 Return spring (No.2Biasing member) 45 Rotating lever (displacement member) 48 Lift spring (No.1Urging member) S sheet

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 1/26 314 B65H 1/00 501 B65H 1/12 310 B65H 1/24

Claims (3)

(57) [Claims] 1. A paper feed cassette is inserted, and a cam member of the paper feed cassette pushes a rotation lever, which is a displacement member , to rotate.
Displaced by Rukoto, transmitted to the lifter the displacement through the first urging member, and rotates against the lifter to the second biasing member, lift the sheet of the paper feed cassette in the lifter In a paper feeder for feeding the sheets in order from the top by rotation of a paper feed roller, the cam member is formed of a material having good slidability separately from a cassette main body of the paper feed cassette, and a side wall of the cassette main body is formed. in part, the selectively attaching the mounting position of the cam member, formed by a plurality in the detachable direction of the sheet feed cassette according to the type of sheet of the paper feed cassette, the paper feeding device. 2. A mounting hole is provided on both side walls of the cassette body.
A plurality of mounting positions are provided, and one of the mounting holes is provided.
2. The paper feed cassette according to claim 1 , wherein said cam member is selectively attached to said cam member by screws . 3. A sheet detecting means for detecting the type of sheet in the sheet cassette, a cam member detecting means for detecting the mounting position of the cam member, and a warning is issued by comparing the detection results of the detecting means. The sheet feeding device according to claim 2, further comprising a warning unit that issues a warning.