JPS6025345B2 - Paper feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet feeding device that feeds sheet materials stacked on a sheet material stacking member to one side or another.

Such a paper feeding device is used, for example, in a copying machine, a simple printing machine, etc., as a means for sequentially feeding transfer paper, photosensitive paper, printing paper, etc. Specifically, sheet materials are stacked and loaded onto a sheet material stacking member, and the stacked sheet materials are loaded from above using a sheet feeding means (generally a rotating paper feed loaf, other air suction method, electrostatic suction method, etc.). Feed one sheet at a time. The upper surface position of the stacked sheet material as it is sequentially fed and consumed one by one is always maintained at a substantially constant standard height determined in relation to the sheet feeding means. It stably feeds the material down to the last piece. The present invention relates to such a paper feeding device, and even if there is a sheet material (including a sheet cassette containing sheet material) on the sheet material stacking member, the sheet material stacking member is not in the normal setting state of the device ( If the sheet-like material is not placed in the correct position on the device, the sheet-like material is prevented from rising; a. Unable to feed paper, poor paper feeding (skewed paper feeding,
(b) If the sheet material is moved upward without the sheet material loading member placed in the correct position on the device, the sheet material may be The purpose is to strictly prevent damage to the equipment, without contacting or interfering with the pond part of the equipment.

To explain specifically based on the embodiment shown in the figure, 1 is a paper feeder board, 2 is a forward/reverse DC motor with a built-in reduction gear fixed to the board 1 with the rotating shaft 3 facing upward, and 4 is the rotating shaft of the motor. Screw village installed integrally with the axis aligned with 3, 5
6 is a female threaded sleeve screwed onto the screw punch, and 6 is a sheet-like material support member (vertically movable member) integrally supported at the upper end of the sleeve.

Due to the rotation of the shaft 3 and screw punch 4 based on the forward rotation of the motor 2, the female threaded sleeve 5 is sent upward and the support member 6 is raised. Conversely, when the motor 2 reverses, the support member 6 descends. Although not shown in the drawings, a vertical guide/rotation regulating member is provided to prevent the support member 6 from rotating when it moves up and down. Although the sheet material P (hereinafter abbreviated as sheet) may be stacked directly on the support member 6, the illustrated example is a sheet cassette 7 as a sheet material stacking member having a front raised bottom surface.
The cassette is shown loaded with sheets P and positioned on a support member 6 at a predetermined position.

8 is a positioning stopper for the cassette 7.

Reference numeral 9 denotes a sheet feeding means, and the illustrated example shows a case of a rotating sheet feeding roller.

In other words, it is normally in a standby state as shown in the figure, in which it is raised a certain distance above the top surface of the stacked sheets P in the cassette, and when a paper feed signal is input, it descends and applies approximately constant pressure to the top surface of the stacked sheets P. When they come into contact with each other, only one sheet is sent out to the top of the stacked sheets P due to the rotational frictional feeding force of the rollers and the action of the separation claw 10. When the leading edge of the fed sheet is guided by the guide plate 11 and sandwiched between the conveyance rollers 2 and 12, the rotary paper feed roller 9 is retracted upward again. Above the support member 6, there is provided means (second detection means) for detecting the upper surface level of the stacked sheets P, which in this example is constructed using a direct-acting potentiometer.

That is, 13 is a direct potentiometer main body, 14 is a vertically movable closing shaft that vertically passes through the main body 13, and 15.
15 is a vertical movement guide bearing for the shaft; 16 is a sheet holding plate fixed to the lower end of the shaft 14 in an inverted T-shape; 16a is a shaft 14;
This is a stopper fixed to the upper end of the shaft to prevent it from slipping out. The sheet pressing plate 16 is in a state of free descent due to its own weight together with the shaft 14, and is normally in a state where it rests on and is received by the uppermost surface of the cassette stack storage sheet P mounted on the support member 6.

Therefore, when the stacked sheets P are fed sequentially from the top, the sheet holding plate 16 is lowered by its own weight by the amount by which the feeding consumption is reduced, and the shaft 14 is positioned downward relative to the fixed potentiometer main body 13. Moving. The output voltage of the potentiometer changes in accordance with the amount of vertical movement of the shaft 14 with respect to the fixed main body 13, and for the sake of convenience, in the illustrated example, it is assumed that the output voltage yv increases as the shaft 14 moves downward.

Then, the output voltage yv is inputted to one input terminal 17 of the differential amplifier 17. The other input terminal 172 of the amplifier 17 also has a signal corresponding to the holding position of the shaft 14 with respect to the fixed potentiometer body 13 when the top surface of the loaded sheet P is at the standard level A in relation to the sheet feeding means 9. Constant voltage terminal 1 with a constant reference voltage yc that corresponds to the voltage output from the potentiometer main body 13
It is always input from 8. The differential amplifier 17 amplifies and outputs the difference voltage between the two voltages yv and Vc, and uses the output voltage to drive the motor 2 in the forward and reverse directions (when Vv-Vc is positive, the motor 2 is driven in the forward and reverse directions). times are reversed).

Therefore, when the uppermost surface of the stacked sheet P is at the standard level A in relation to the paper feeding means 9, the output voltage Vv from the potentiometer body 13 matches the reference voltage Vc, so that the differential amplifier 17 The output voltage is zero and the motor 2 does not rotate.

In this state, when the stacked sheets P are sequentially fed from the top by the operation of the paper feeding means 9, the sheet pressing plate 16 is lowered in response to the decrease in the feeding. Along with this, the shaft 14 also descends with respect to the fixed potentiometer body 13, so a voltage of Vv>Vc corresponding to the amount of descent is output from the potentiometer body 13 to the differential amplifier 17. As a result, the amplified positive differential voltage Vv-Vc is output from the amplifier 17, the motor 2 rotates in the normal direction, and the sleeve, the support member 6, the cassette 7, and the loaded sheets P are all raised. Along with the rise, the sheet holding plate 16 and the shaft 14 also rise, and the output voltage Vv of the potentiometer main body 13 approaches Vc, Vv=
When the voltage reaches Vc, the output of the amplifier 17 becomes zero and the motor 2 stops rotating. That is, the top surface of the stacked sheet P is automatically corrected to the standard level A again. In this way, as the stacked sheets P are sequentially fed and consumed, the support member 6 is raised one by one and the upper surface of the stacked sheets P is automatically corrected to the required standard level A at all times. The accommodated sheets P can be stably fed from the first sheet to the last sheet. Numerals 27 and 29 are photoelectric sensors comprising a lamp and a light receiving element, which serve as means for detecting the presence or absence of the sheet P on the support member.

That is, 27 is a lamp arranged on the upper surface of the support member 6, 28 is a through hole formed in the cassette bottom plate corresponding to the lamp 27 when the cassette 7 is properly set on the support member 6,
29 is a light receiving element disposed above the cassette 7 on an extended line connecting the lamp 27 and the through hole 28. When even one sheet P exists in the cassette 7, the optical path connecting the lamp 27 and the light receiving element 29 is blocked by that sheet, and the light receiving element 29
9 does not receive the light from the lamp 27. As a result, the sheet P
is detected. When the stacked sheets P are fed and consumed one by one and the inside of the cassette 7 becomes empty, the light from the lamp 27 hits the element 29 through the through hole 28, and the no-sheet detection circuit 3 is activated.
A positive potential is output from 0 to drive the switch circuit 32 via the OR circuit 31, and a bias voltage larger than the reference voltage Vc is output from the switch circuit 32 to the terminal 1 72 of the differential amplifier 17.

As a result, the motor 2 rotates in the opposite direction and the support member 6 moves downward, and when its lower surface hits the stopper 33 provided on a predetermined positioning layer, the support member 6 resists the downward force caused by the rotation of the motor. Its descent is forcibly stopped and held in a standby state. In this case, as the support section 6 descends, the sheet presser plate 16 and the shaft 14 descend to some extent due to their own weight, but beyond that, the stopper 16a hits the upper end surface of the bearing 15, so they do not descend and are held in place. . Even when the cassette 7 in which the sheet P still exists is removed from the support member 6 in order to replace it with another cassette, the light from the lamp 27 enters the light receiving element 29, so the support member 6 is lowered and stands by. state.

When the cassette 7 loaded with the sheets P is set in the correct position on the support member 6 which is in the waiting state for descending, the optical path between the lamp 27 and the element 29 is again interrupted and the circuit 30 The output to the OR circuit 31 becomes zero.

As a result, the output of the switch circuit 32 to the differential amplifier 17 becomes zero, and the voltage applied to the terminal 172 of the differential amplifier 17 becomes only the reference voltage Vc. For that purpose motor 2
turns to normal rotation and the sleeve 5, support member 6, cassette 7,
The entire cut sheet P rises. Then, when the output voltage Vv of the potentiometer main body 13 and the reference voltage Vc are balanced, that is, when the upper surface of the stacked sheets P is raised to the standard level A, the rotation of the motor 2 is stopped and a paper feeding standby state is entered. MS is a microswitch as a means (first detection means) for detecting whether or not a sheet-like material, in this example, a sheet cassette 7 containing the sheet-like material, is placed in the correct position on the supporting portion 6. and
When the cassette 7 is stacked and set in the correct position on the support member 6, it is held in the open state by contact with the cassette, and when the cassette 7 is deviated from the correct position, or when the support member When the cassette on top 6 is not present, it is in a closed state and outputs a positive potential to an off circuit 31 separate from the circuit 30.

Therefore, unless the cassette 7 is reset or set in the correct position, the support section 6 will not move upward.
It remains in the descending standby state. Incidentally, in the process of removing the empty cassette 7 from the support member 6 and in the process of resetting the cassette containing a new sheet, the optical path of the lamp 27 and the element 29 as sheet presence/absence detecting means is temporarily blocked by the cassette 7. There are times when the output of the circuit 30 becomes zero.Since the positive potential continues to be input to the OR circuit 31 from the microswitch MS mentioned above, the support section 6 is maintained in the lowering standby state. No particular problem will arise.

Since the support section 6 gradually increases in accordance with the feeding consumption of the stacked sheets P, the current remaining amount of the stacked sheets P can be easily displayed using this.

Reference numeral 19 indicates the pointer, whose base is integrally attached to the support section 6 and whose tip is exposed to the outside through a vertically elongated hole 21 formed in the device exterior plate 20.

Reference numeral 22 indicates a scale carved on the exterior plate surface along the vertical edge of the elongated hole 21.

When there is a sufficient amount of sheets, the support member 6 is in the lowered position, so the tip of the pointer 19 is also located below the hole 21, indicating that the current amount of sheets is sufficient. As the support member 6 gradually rises as the sheets are fed and consumed, the pointer 19 also rises, and the current remaining amount of sheets is displayed. As another example of display means, the upper end of the super-driving wheel 24 of a fixed direct potentiometer main body 23 is integrally attached to the lower surface of the support section 6, and the meter main body 23 is supported as the support member 6 rises. It is also possible to display the current remaining amount of sheets by instructing the meter 26 to change the output voltage of the meter 23 via the amplifier 25. As described above, in the paper feeding device of the present invention, even if there is a sheet material (including a sheet cassette containing sheet material) on the sheet material stacking member, the sheet material stacking member can be placed in the correct position on the device. Since the sheet-like material does not rise when it is not placed in the paper, the above-mentioned objectives a and b are well achieved, and this type of picture paper device is effective and suitable.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating an embodiment of the present invention, and FIG. 2 is a perspective view of the current remaining amount display section of the sheet. 2 is a forward/reverse motor, 6 is a sheet-like material support member, 7 is a cassette containing stacked sheets P, 13 and 14 are potentiometers for detecting the upper surface level of stacked sheets P, 17 is a differential amplifier, and 18 is a reference voltage Vc. Terminal 19 that outputs
, 26 is a pointer or meter for displaying the current remaining amount of the sheet. Tsutomu 1 figure true color 2 figure

Claims (1)

[Claims] 1. A paper feeding device having a feeding means that sequentially feeds stacked sheet materials from the top, including a vertically moving member that moves the sheet materials up and down, and a vertically moving member that is placed on the moving member and loads the sheet materials. a driving device that controls the vertical movement of the vertically movable member; a first detection means that detects that the stacking member on the vertically movable member is placed in a position where it can be moved upward; and a stacked sheet. A second detection means detects that the upper surface of the material has risen to the standard position, and if it is not detected by the first detection means that the loaded member on the vertically moving member is placed in a position where it can be moved upwardly, it moves up and down. The raising of the member is prohibited, and when it is detected that the member is placed in a position where it can be moved upwardly, the vertically movable member is allowed to rise, and the second detection means causes the upper surface of the loaded sheet material to reach the standard position. A sheet feeding device comprising: circuit means for stopping the upward movement of the vertically moving member when the upward movement is detected.