JPH02198949A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce the sheet transport resistance by shifting a detecting means which detects the existence of a sheet in a sheet accommodating device and can be shifted by freely in a detecting position, accompanied with the shift of the sheet transporting device. CONSTITUTION:A detecting means consisting of a sensor arm 81 and a sheet existence sensor 85 detects the existence of a sheet S accommodated in a sheet storage device 1 from the contact of the top edge 81C of the sensor arm 81 which can be swung around a shaft 80. The detecting means 81 and 85 are positioned at a retreat position separated from the sheet accommodating device 1, interlocked with the turn of a releasing arm, when the sheet accommodating device 1 is mounted and demounted for a guide block 86 for forming a paper feeding passage 82 with a guide plate 83, and when the sheet accommodating device 1 is mounted into the machine body, the detecting means 81 and 85 are returned to the sheet S detecting position in interlocking. Thus, the transport resistance in sheet transport is reduced, and the troubles of aslant traveling of sheet and paper transport disorder can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an image forming apparatus such as a copying machine or a laser beam printer. It is installed in an image forming apparatus (hereinafter referred to as a copying machine) equipped with a sheet storage device (hereinafter referred to as a cassette) which is detachably attached in the direction of the image forming apparatus.

(B) Conventional technology Conventionally, a copying machine is known which is equipped with a cassette that stores a large number of sheets inside the machine and is detachably mounted in a direction perpendicular to the sheet conveyance direction. teeth,
When the cassette is installed in the machine, a sheet presence/absence sensor detects the presence or absence of a sheet stored in the cassette.

However, in this copying machine, when the cassette is installed or removed, the sensor lever of the sensor that detects the presence or absence of sheets stored in the cassette may come into contact with the cassette, which may damage the sensor arm.

To overcome this drawback, the applicant has devised a copying machine equipped with a sensor whose sensor arm moves up and down as the cassette is attached and detached. The copying machine 10 is shown in FIG.
As shown in FIG. 7 (not publicly known), it has a cassette 1 detachably attached to the fuselage 11, and the cassette 1
can be pulled out toward the front side of the fuselage 11. Further, a pressure bonding plate 13 is supported on the upper part of the body 11 so as to be openable and closable. A handle 4 is provided on the front side of the cassette 1.
4, and handles 45 for lifting the cassette 1 are provided on the left and right sides of the cassette 1. Further, the cassette 1 has an intermediate plate 2 on which a large number of sheets S are loaded, and a regulating plate 3 that regulates the lateral movement of the sheets S. A plurality of long holes 4.4 are opened in the sheet width direction in the middle plate 2, and the regulating plate 3 is configured to be able to move into these long holes 4.4 according to the sheet size. and protrudes from the elongated hole 4. Further, a separating claw 5 for separating the sheets S one by one is provided at the upper part of the downstream end of the regulating plate 3, and a separating claw 5 for separating the sheets S one by one is also provided at the upper part of the downstream end of the side plate 8 on the right side of the middle plate 2. A claw 5 is provided. And cassette 2
A shaft 6 connected to a motor (not shown) is rotatably supported on the upper part of the paper sheet, and a plurality of paper feed rollers 7 are fixed to the shaft 6 so as to correspond to various sheet sizes. Further, the middle plate 2 is urged upward by a spring 9, and the sheets S stacked on the middle plate 2 are pressed against the paper feed rollers 7.

A mounting plate 66 is attached to the body 11 above the cassette 1.
A light-transmissive sheet presence/absence sensor 67 is attached through the sensor 67, and a shaft 69 is supported by a body frame (not shown) facing the sensor 67. Further, on the shaft 69, there is provided a sensor lever 7 whose one end 70a is wide and shaped like a letter when viewed from the side.
0 is swingably supported, and a detection roller 71 is supported at the other end of the lever 70 so as to be rotatable in the cassette 1 attachment/detachment direction. Further, a receiver member 68 is provided on the back side of the portion where the recesses 35 are located, and the receiver is a member 68.
8 uniformly transmits the biasing force of the spring 9 to the intermediate plate 2. Further, the spring 9 is adapted to move together with the regulating plate 3.

Then, by installing the cassette 1, the detection roller 71 is moved from the solid line position by the sheet S stored in the cassette 1.
Move to the dotted chain line position (see Figure 13) and press sensor lever 7.
The sensor 67 is turned off when the one end 70a of the sheet sensor 67 blocks the light emitting part and the light receiving part of the sheet presence/absence sensor 67.

Then, the control unit that receives the OFF signal from the sensor 67 determines that there is a sheet S in the cassette 1. Then, when the stacker key is pressed, the paper feed roller 7 is moved from the cassette 1 to the paper feed roller 7.
The sheet S is fed, the image is copied, and the sheet S is ejected from the machine body 11. Through the same operation, the copying operation is repeated, and when there is no more sheet S in the cassette 1, the detection roller 71 is activated. , falls into the hole 48 formed in the middle plate 2, and moves from the position indicated by the two-dot chain line to the position indicated by the solid line. As a result, one end 70a of the sensor lever 70 also moves from the two-dot chain line position where it blocks the light emitting part and the light receiving part of the sheet presence/absence sensor 67 to the actual position where it does not block the space between them, and the sensor 67 is turned on. Furthermore, the control unit that receives the ON signal from the sensor 67 determines that there is no sheet S in the cassette 1, and issues an alarm on the display unit. Then, the operator who confirms the alarm pulls out the cassette 1 and inserts the sheet S into the cassette 1.
is loaded and attached to the aircraft body 11.

(C) Problems to be Solved by the Invention By the way, in the above-described copying machine, since the detection roller 71 rotates only in the cassette attachment/detachment direction, it causes conveyance resistance when feeding the sheet S, causing skewing and feeding of the sheet S. There was a problem that paper defects could occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus that eliminates the above-mentioned problems by preventing conveyance resistance from occurring during sheet feeding.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and as illustrated with reference to, for example, FIGS. , inside the fuselage (11), there are many seats (
In an image forming apparatus (10) comprising a sheet storage device (1) that stores a sheet S) and is detachably attached in a direction perpendicular to the sheet conveyance direction, the sheet storage device (1)
A detection means (81, 85) is provided for detecting the presence or absence of a seat (S) stored in the seat storage device, and the detection means (81, 85) is connected to the seat storage device (1) when the seat storage device (1) is attached or removed. (1); a detection position for detecting the seat (S) stored in the seat storage device (1) when the seat storage device (1) is installed in the aircraft body (11); It is characterized in that it is configured to move as the storage device (1) moves.

Further, the sheet storage device (1) and the detection means (8
1, 85).

(N) Function Based on the above configuration, the detection means (81, 8
5) is located at a retracted position away from the seat storage device (1) when the seat storage device (1) is attached or removed, and when the seat storage device is installed in the aircraft body (11), the seat The storage device (1) is located at a detection position for detecting the sheets (S) stored therein.

Note that the above-mentioned symbols in parentheses are shown for reference and do not limit the configuration in any way.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 2, the cassette 1 is removably mounted in the body 11 of the copying machine 10, and is mounted on guides 12.12.
The sheet can be pulled out in a direction perpendicular to the sheet conveyance direction. Then, the body 11 is attached to the crimp plate 1
3, platen 15, light source 16, mirrors 17, 18, 19
, 20, 21, 22, and a lens 23, and a pair of transport rollers 25 and a pair of register rollers 26 are provided downstream of the cassette 1. Further, an image forming section 27 is arranged downstream of the roller pair 26, and a conveyor belt 29 and a fixing device 30 are arranged downstream of the image forming section 27. A pair of paper discharge rollers 31 is provided downstream of the fixing device 30, and a paper discharge tray 32 is provided downstream of the pair of paper discharge rollers 31.

Further, the cassette 1 is shown in FIGS. 3, 4, and 5 (
As shown in a) and (b), a block 33 for sheet size detection is detachably attached to the back side in the cassette insertion direction C, and the block 33 is disposed on the body 11 side, which will be described later. Sheet size detection switch 83a, 6
3b and 63c are operated by pressing, and the blocks 33 can be replaced depending on the sheet size.

Furthermore, recesses 35 are formed in the middle plate 2 as relief portions at positions facing the third and subsequent paper feed rollers 7a and 7b from the right side in the paper feed direction, and these rollers 7a and 7
When feeding a narrow sheet S that is not located in the portion b, these paper feed rollers 7a and 7b are configured not to contact the middle plate 2. Note that the reference numeral 36 in the figure is a regulation plate that regulates the backward movement of the sheet S, and the regulation plate 36
There are holes 40 and 40 in the main body of the cassette corresponding to the sheet size.
...and a hole 4 that restricts the movement of the vertically long sheet S to the back side
It can be moved and attached to 1... In addition, a recessed portion 42 as a first engaging portion is carved in the upper part of the rear side of the cassette 1, and a recessed part 42 as a first engaging part is carved in the lower part of the rear side of the cassette 1. A protrusion 43 is protrudingly provided on the cassette 1 as a second engaging portion that fits into the recess 42 of the lower cassette 1 to position the cassette 1. Stoppers 46 made of resin are disposed at both ends of the rear side of the cassette 1.
is composed of a stopper receiving part 47, a stepped part 49, a slope 50, and a spring part 51 (see FIG. 6), and the stopper 46 is elastically deformed when the cassette 1 is attached to the body 11. The amount of protrusion and the elastic limit are set so that the upper surface of the cassette 1 is flush with the upper surface of the cassette 1.

Note that 48 in FIG. 4 is a hole for detecting the presence or absence of a sheet. 1(a) near the paper feed roller 7.
), As shown in (b), a shaft 80 is supported substantially horizontally, and a sensor arm 81 is swingably supported by the shaft 80. Also, one end 81a of the arm 81
A sheet presence/absence sensor 85 is provided on the guide plate 83 constituting the upper part of the paper feed path 1a82 near the sheet feed path 1a82, and the sensor 85 is turned on or off by one end 81a of the sensor arm 81. Furthermore, the paper feed path 82
is composed of a guide plate 83 and a guide block 86 provided opposite to the guide plate 83, and the tip of the block 86 is rib-shaped. and,
A shaft 87 is supported on the front side of the block 86,
A release arm 89 is swingably supported by the shaft 87. Further, the arm 89 is urged to swing counterclockwise by a coil spring 90, and one end 89 of the arm 89
A is adapted to contact the tip 81b of the horizontally extended portion of the sensor arm 81 to urge the arm 81 to swing clockwise. Note that the sheet presence/absence sensor 8
5 is connected to a control section 91. When the cassette is not attached, the arm 81 is in the position shown by the broken line in FIG. 1(a), and the sensor 85 is in the OFF state.

In addition, on the upper part of the body 11 where the cassette 1 is installed,
As shown in FIG. 7(a), a groove 51 into which the stopper 46 fits, a stepped portion 52 into which the stopper 46 engages, and an inclined surface 53 on the front side of the stepped portion 52 are formed.

Furthermore, as shown in FIG. 8, in the center of the front side of the cassette 1, a positioning plate 55 made of a steel plate is fixed with screws or the like.
It is adapted to be attracted to a magnetic catch 57 provided on the side via a mounting plate 56. And the mounting plate 5
6 can be moved and adjusted several meters in the direction of the arrow with respect to the fuselage 11, and as a result, the magnetic catch 5
It is designed to adjust the position of 7.

Further, as shown in FIGS. 9(a) and 9(b), a mounting plate 59 is disposed in a portion of the fuselage 11 facing the block 33, and the mounting plate 59 is fixed to the fuselage 11. A pin 61 with a bulged tip protrudes from the bracket 60.
A spring 62 is compressed between the tip of the bottle 61 and the mounting plate 59. Furthermore, the mounting plate 59 is provided with switches 83a, 63b, and 63c for detecting the sheet size based on the position of the pushbutton 33, and a switch 63d for detecting the presence or absence of the cassette 1. , these switches 83
A positioning protrusion 65 for ensuring a distance between the mounting plate 59 and the cassette 1 body is provided at a position sandwiching the cassette 1 body.

In addition, when the sheet S is located up to the paper feed rollers 7a and 7b, as shown in FIG. 10 and FIG. The plate auxiliary member 37 is configured to be attached to the recess 35, thereby ensuring the pressing force of the sheet S against the paper feed rollers 7a, 7b.

As shown in detail in FIG. 12, the intermediate plate auxiliary member 37 has claws 37a at both ends.
It is supported by being inserted into slit-like holes 35a, 35a bored in the depression 35.

Further, as shown in FIGS. 13(a) and 13(b) in detail, the separation claw 5 has a U-shape when viewed from the front, and one end 5a thereof is attached to a shaft 72 supported by the cassette 1 body. It is rotatably supported by. Further, a link lever 73 is swingably supported at the lower part of the separation claw 5 by a shaft 75 supported by the cassette body, and one end 73a of the lever 73
However, by contacting the intermediate plate 2 loaded with sheets S and swinging clockwise, the other end 73b urges the separation claw 5 to rotate counterclockwise.

Since this embodiment has the above configuration, the copying machine 10
When stacking a plurality of cassettes 11 outside the machine body 11, the operator inserts the protrusion 43 at the bottom of the upper cassette 1 into the recess 42 at the top of the lower cassette 1. As a result, multiple cassettes can be loaded without the bottom surface of the upper cassette 1 coming into contact with the top surface of the lower cassette 1.
can be stacked (Fig. 7 (a), (b)
reference).

When storing the largest size sheet S in one of the stacked cassettes 1 and loading it into the copying machine 10, the operator moves the regulation plate 3 to the left end of the cassette, and Paper feed rollers 7a, 7
A middle plate auxiliary member 37 is placed in the recesses 35, 35 at a position opposite to b.
Attach. When a large number of maximum size sheets S (for example, width D) are loaded on the middle plate 2 of the cassette 1 (see FIG. 10), the middle plate 2 descends against the spring 9 due to the weight of the sheets S. . Furthermore, when loading the sheets S up to a full load, the operator loads the full number of sheets S on the intermediate plate 2, and moves these sheets S in the direction of the arrow F (
(see FIG. 14(b)) against the spring 9. and,
Along with these sheets S..., the middle plate 2 is also pushed down in the F direction, and the middle plate 2 comes into contact with one end 73a of the link lever 73 to swing the lever 73 clockwise. after that,
By swinging the lever 73 clockwise, the lever 73
The other end 73b contacts the separation claw 5 and rotates the separation claw 5 counterclockwise, and the separation claw 5 moves from the two-dot chain line position to the solid line position (see FIG. 14 (1)). , its tip is pushed up from the top surface of the sheet S.... Further, the operator moves the sheet S in the conveying direction until the leading edge of the sheet S is located below the leading edge of the separating claw 5, and then releases the force in the direction F, which causes the intermediate plate 2 and the sheet to move. S...
is urged upward by a spring 9, and the uppermost sheet S of the sheets S is brought into contact with the tip of the separating claw 5 and positioned. At this time, the biasing force of the spring 9 in the portion where the recesses 35 are located is uniformly transmitted to the intermediate plate 2 by the receiving member 68. Furthermore, at this time, one end 73a of the link lever 73 is not in contact with the middle plate 2, and the other end 73b is not in contact with the separation claw 5, so that the link lever 73 is not in contact with the middle plate 2 and the separation claw. There will be no impact.

Then, transfer the cassette 1 full of sheets S... to the aircraft 1.
1, when the operator places the side of the cassette 15 on the rail 12.12 and pushes it in the direction of arrow G (see FIG. 7(a)), the upper part of the stopper 46 is raised by the inclined surface 53 on the side of the fuselage 11. When pushed downward, the top surface of the stopper 46 is deformed and becomes flush with the top surface of the cassette 1. Then, when the stopper 46 passes over the stepped portion 52, the deformation of the stopper 46 returns to its original state, and the stopper 46 and the stepped portion 5
2 engage with each other, and the stepped portion 49 comes into contact with the cassette body to prevent deformation, making it impossible to easily pull out the cassette 1 in the direction of arrow H (see FIG. 7(b)). If you need to pull out cassette 1, remove cassette 1.
rotate in the direction of the arrow (see FIG. 7(c)) to position the lower end of the cassette 1 at the retracted part of the rail 12, so that the upper part of the stopper 46 is lower than the stepped part 52 of the fuselage 11. At the same time, pull out the cassette 1 in the direction of arrow J.

Furthermore, when the cassette 1 is pushed into the machine body 11, the positioning plate 55 is attracted to the magnetic catch 57, and the cassette 1 is thereby positioned (see FIG. 8).
The positioning protrusion 65.65 on the back side of the cassette 1 is located on the mounting plate 5.
9 and moves the mounting plate 59 against the springs 62 and 62 to maintain a predetermined distance between the tip of the switch 63a and the main body of the cassette 1. Then, the block 33 turns on one of the switches 63a, 63b, and 63c for sheet size detection, for example, 63b, and the cassette 1 body turns on the switch 63d for detecting the presence or absence of a cassette. The ON signal is transmitted to the control section.

Also, by installing the cassette 1, a part 1a of the cassette 1
comes into contact with one end 89b of the release lever 89, and the lever 89
is swung clockwise, and the lever 89 is swung from the solid line position to the chain line position (see FIG. 1(b)).Then, the sensor arm, which had been biased clockwise by one end 89a of the lever 89, is swung clockwise. The arm 81 swings counterclockwise due to its own weight and moves from the chain line position to the solid line position (FIG. 1(a)), and one end 81c of the arm 81 abuts the uppermost sheet S (FIG. 1(a)). a)). It is more preferable for the one end 81C of the sensor arm 81 to contact the sheet S at the timing just before the cassette is loaded in order to prevent the sheet from shifting. Since the sensor 85 is again blocked between the sensor 85 and the light receiving section, the sensor 85 remains OFF. Then, a control section 91 receives the OFF signal from the sensor 85.
determines that there is sheet S in cassette 1. Then, place the original on the platen 15 and press the start key.
Lamp 16, mirror 17, 18, 19.20, 21, 2
2. The lens 23 reads the image of the document and forms the image on the image forming section 27. On the other hand, the sheets S are separated from the cassette 1 by the paper feeding roller 7 and the separating claw 5.5, and only the uppermost sheet S is fed. At this time, since the sensor arm 81 is swingable in the sheet conveyance direction (left rotation or right rotation in FIG. 1(a)), there is no conveyance resistance. The sheet is conveyed by a pair of registration rollers 25 to a pair of registration rollers 26, and a conveying force is applied by a pair of conveying rollers 25 that abuts the nip of the roller pair 26 and slips, thereby correcting the skew. Then, it is transported in synchronization with the image on the image forming section 27 by a pair of registration rollers 26 that start rotating at a predetermined timing. Further, the image forming section 27 copies an image on the sheet S, and the sheet S is conveyed to the fixing device 30 by the conveyor belt 29 . Then, the image is fixed on the sheet S by the fixing device 30, and the sheet S is discharged to a paper discharge tray 32 by a pair of paper discharge rollers 31.

Further, when loading medium-sized sheets S (for example, width E) into the cassette 1, the operator moves the regulating plate 3 to match the sheet width, and places the intermediate plate auxiliary only in the recess 35 opposing the paper feed roller 7b. Attach the member 37 and press the paper feed roller l.
Remove the member 37 opposing ea (see FIG. 10).

Thereafter, image forming work is performed by the same operations as described above.

Then, when there is no more sheet S in the cassette 1, one end 81c of the sensor arm 81 falls into the hole 48, and the sensor arm 81 swings counterclockwise. As a result, the other end 81a of the sensor arm 81 moves from a position where it blocks the light emitting part and the light receiving part of the sheet presence/absence sensor 85 to a position where it does not block the space between the light emitting part and the light receiving part, and the sensor 85 turns ON (Fig. 1(c) )
Furthermore, the control section 91 which receives the ON signal of the sensor 85 determines that there is no sheet S in the cassette 1 and issues an alarm on the display section. Then, the operator who confirms the alarm pulls out the cassette 1 and replenishes the cassette 1 with sheets S. When pulling out the cassette 1, when the part 1a of the cassette 1 separates from one end of the release lever 89 immediately after the pulling operation, the lever 89 swings counterclockwise due to the biasing force of the coil spring 90, and the lever 89 The tip 81b of the sensor arm 81 is pushed and swung clockwise to come out of the hole 48, and then gradually retreats to the position shown by the solid line in FIG. 1(b). As a result, the sensor arm 8
1 never comes into contact with cassette 1.

Although the apparatus according to the present invention is as described above, it is not limited to this embodiment. For example, one end 81c of the sensor 81 may be a rotatable roller. The rotation axis of the roller is parallel to the axis of the roller 7. .

(G) As described in detail, the present invention includes a detection means that detects the presence or absence of sheets stored in a sheet storage device and is movable in the sheet conveyance direction, and the detection means includes: A retraction position where the seat storage device is separated from the seat storage device when the seat storage device is attached or removed; a detection position where the seat storage device detects the seat stored when the seat storage device is installed in the aircraft; Since it is configured to move along with the movement, it is possible to prevent conveyance resistance from occurring during sheet feeding, thereby preventing the sheet from being skewed or from being fed incorrectly.

[Brief explanation of the drawing]

FIGS. 1(a), 1(b), and 1(c) are diagrams showing essential parts of an image forming apparatus according to the present invention. Further, FIG. 2 is a front sectional view showing an image forming apparatus according to the present invention. Further, FIGS. 3 to 13(a) and 13(b) are diagrams showing essential parts of the image forming apparatus according to the present invention. FIG. 14 to FIG. 17 are diagrams showing an image forming apparatus devised by the applicant. 1... Seat storage device

Claims (1)

[Scope of Claims] 1. In an image forming apparatus comprising a sheet storage device that stores a large number of sheets in a body and is detachably attached in a direction perpendicular to the sheet conveyance direction, the sheet storage device stores sheets in the sheet storage device. A detecting means is provided that detects the presence or absence of a sheet in the sheet storage device and is movable in the sheet conveyance direction, and the detection means is moved to a retracted position separated from the sheet storage device when the sheet storage device is attached or removed, and a detection device that is moved between the sheet storage device and the sheet storage device. 1. An image forming apparatus comprising: a detection position for detecting a sheet stored in the sheet storage device when the sheet storage device is installed in a machine body; and a detection position configured to move as the sheet storage device moves. 2. The image forming apparatus according to claim 1, further comprising an engaging member that engages with the sheet storage device and the detection means.