JPH0428648A - Paper feed mechanism - Google Patents

Abstract

PURPOSE:To modify dislocated paper automatically and satisfactorily even if it is different in thickness, material and condition by issuing a preset control signal from a control means in accordance with the result of detection so that a paper correcting means corrects the dislocation of paper in accordance with the control signal. CONSTITUTION:A paper detecting means 1 detects the dislocation of paper, if out of place, and a control means 2 issues a control signal in accordance with the detection result of the paper detecting means 1. Next, a paper correcting means 3, which has a pressure variable means 4 control a roller 5 in accordance with a preset control signal from the control means 2 and vary the pressure of the roller 5 applied to paper, corrects the dislocation of paper.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a paper transport mechanism that transports paper.

[Prior Art] Conventionally, in a paper transport mechanism that transports paper, there have been cases where the paper does not travel straight along the transport path, especially in the paper transport path from the paper feed cassette to the photoreceptor of an image forming apparatus. . For example, in the case of a manual feed tray where the operator inserts paper one sheet at a time, the operator may insert the paper diagonally and the paper will not advance straight, and in the case of a paper feed cassette,
The problem was that the paper was placed diagonally in the paper cassette, which caused the paper to be inserted diagonally and not advance quickly.

Therefore, it has been proposed that a paper detection sensor be provided near the copy paper end regulating members of the copy paper container, and the paper feeding operation will be performed based on the output of this sensor.
11445).

In addition, for the purpose of correcting copy paper (paper) that has been fed diagonally, "When the leading edge of the paper comes into contact with the pair of registration rollers, the driven roller enters a slip state, so that the inclination of the paper is corrected. It has been proposed (Japanese Unexamined Patent Publication No. 118542/1983) that Specifically, as shown in FIG. 7, when the leading edge of the paper P hits the pair of registration rollers 80, the inclination of the paper P is corrected by the driven roller 70.

[Problems to be Solved by the Invention] However, Japanese Patent Application Laid-open No. 8-11 described in the prior art
The proposal in Publication No. 445 only outputs a warning to the operator, and there is a problem in that automatic correction input is not performed.

Furthermore, the proposal in Japanese Patent Application Laid-Open No. 118542/1983 is that since paper thickness, paper properties, size, etc. differ depending on the paper, it is practically impossible to control the driven roller delicately to accommodate all types of paper. Therefore, there was a problem that defective corrections were unavoidable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a paper transport mechanism that effectively corrects paper misalignment.

[Means for Solving the Problems] The present invention provides a paper transport mechanism that transports paper, including a paper shift detection means for detecting a shift of the paper when the paper is not in a regular position, and a paper shift detection means. a control means for issuing a predetermined control signal based on the detection result of the roller; and a pressure for controlling the roller according to the predetermined control signal of the control means to change the pressure of the roller applied to the paper. A paper conveyance mechanism comprising a variable means and a paper correction means for correcting misalignment of the paper.

[Function] In the present invention, the paper detecting means detects the misalignment of the paper when the paper is not in the normal position, and the control means issues a predetermined control signal based on the detection result of the paper misalignment detecting means, The pressure variable means of the paper correcting means corrects misalignment of the paper by controlling the roller and changing the pressure of the roller applied to the paper based on a predetermined control signal from the control means.

[Embodiment] An embodiment of the paper conveyance mechanism according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a paper transport mechanism according to the present invention.

The paper misalignment detection means 1 detects paper misalignment when the paper is not in the correct position. A photo sensor 1 is provided at the tip of the paper width direction regulation guide 10 of the paper storage section 11, just outside the paper placement location.

As shown in FIG. 2(b), when the light from the light-emitting element 1x is received by the light-receiving element 1y, the paper is in the correct position, and the light from the light-emitting element 1x is being received by the light-receiving element 1y.
If no light is received, the paper is misaligned and the light is not passing through. Therefore, the paper misalignment is detected based on whether or not the light receiving element 1y receives light. Further, instead of using a transmission type photosensor, a reflection type photosensor may be used. In that case as well, a reflective photosensor is provided at the above-mentioned position near the paper width direction regulation guide 10 of the paper storage section 11, and as shown in FIG.
If the light from the light-emitting element 1x is not received by the light-receiving element 1y, the paper is in the correct position, and the light from the light-emitting element 1x is not received by the light-receiving element 1y.
If the light is received at y, the paper is misaligned, so the light is reflected by the paper and received. Therefore, if light is received, the paper is misaligned, so the misalignment of the paper is detected.

The control means 2 is for generating a predetermined control signal based on the detection result of the paper misalignment detection means 1.

Specifically, as will be described later, in simple terms, if the detection signal of the paper misalignment detection means l is an analog signal, it is changed to a digital signal, and if it is a digital signal, it is made consistent and sent to the input port of the microcomputer. Calculations are performed manually and by a microcomputer, and a predetermined control signal is sent from the output port of the microcomputer to paper straightening means 3, which will be described later. In this way, the control means 2 may be implemented as software using a microcomputer, or
It may be realized by installing a dedicated hardware circuit.

The paper correcting means 3 corrects misalignment of the paper based on a predetermined control signal from the control means 2.

Specifically, as shown in FIG. 2(a), the paper straightening means 3 includes a paper feed roller 5 in the leading edge direction of the paper, a shaft 31 that supports the paper feed roller 5, and a shaft 31 that supports the paper feed roller 5. It has a pressure variable means 4 that changes the pressure of the paper feed roller 5 applied to the paper, and when the paper is misaligned, for example, when the paper feed roller 5 is a driven roller, the side where the paper is misaligned is Pressure is applied to the paper feed roller 5 which is further away from the paper by the pressure variable means 4,
This applies resistance to the paper in that area and hinders its forward movement.On the other hand, the part of the paper on the paper feed roller 5 side that is not pressurized continues to move forward smoothly, and as a result, the misalignment of the paper is corrected. . The pressure variable means 4 indirectly applies pressure to the paper by applying pressure to the paper feed roller 5. This corrects paper misalignment. Specifically, in the pressure variable means 4, as shown in FIG. The other end is connected to the movable core of the solenoid 35.

Then, by energizing the coil in the solenoid 35, the movable iron core is attracted downward, so that the pressure lever 32 is lowered downward in FIG.
Since the paper feed roller 5 also moves downward, the paper feed roller 5 is pressed against the paper P.

Furthermore, when the excitation of the coil of the solenoid 35 is stopped, the pressure lever 32 returns to its original position due to the elastic member 34, and the shaft 31 of the paper feed roller 5 also returns to its original position. Next, as the pressure variable means 4, one using an eccentric cam 41 as shown in FIG. 4(a) will be described. The eccentric cam 41 is a cam in which the center of the outer periphery and the center of the circular gear provided on the inner surface are shifted from each other.

As shown in FIG. 4(a), the shaft 31 of the paper feed roller 5 and the outer periphery of the eccentric cam 41 are in contact with each other, and the gear on the inner surface of the eccentric cam 41 is attached to the shaft 43 of a motor (not shown). The spur gears 44 are in mesh with each other. Then, by slightly rotating the motor, the eccentric cam 41 is slightly rotated.

Then, the center of the outer peripheral surface of the eccentric cam 41 is aligned with the eccentric cam 41.
Since the eccentric cam 41 is deviated from the central axis, the eccentric cam 41 moves from the position shown in FIG.
#+31 is pushed downward and moves, and the paper feed roller 5 applies pressure to the paper. In this way, a pressure variable means 4 using an eccentric cam is also conceivable.

Note that the paper feed rollers 5 do not need to be a pair of rollers as in the illustrated embodiment, but may be three or more rollers, and even if there are - rollers, they do not have to be horizontally long. If there is, the left and right pressure balance can be effectively changed, so it is effective as the paper feed roller of the present invention.

Next, the operation of the same embodiment of the paper conveyance mechanism according to the present invention will be described.

First, a sheet of paper is about to be conveyed within the paper conveyance mechanism. Then, light from the light emitting elements of the transmissive photosensor 1 as the sheet displacement detecting means 1 near both sides of the sheet width direction regulation guide 10 of the sheet storage section 11 is emitted toward the light receiving element. While this light is being received by the light-receiving element, there is no misalignment on the paper, but when the paper blocks this light, there is misalignment on the paper. The direction in which the paper is misaligned can be determined depending on which photosensor 1a or 1b on both sides of the paper does not receive light. Therefore, for each photosensor 1, different signals (for example, 0.
1 digital signal) is input to the input port of the microcomputer 2 as the control means 2 (if this signal is an analog signal, it is converted to a digital signal; (If there is no consistency in voltage, etc., it is necessary to ensure consistency). Then, the microcomputer 2 as the control means 2 temporarily stores the input detection result signal at the address of a predetermined storage element, and refers to the storage element when necessary according to the program.
The calculation is performed, and as a result, a control signal is sent to the paper straightening means 3. That is, this program is shown in a flowchart shown in FIG. 6, which will be described later. Next, for example, the photosensor 1b
When the light is not received, as shown in FIG. 5(a), since the paper has shifted upward on the drawing, the paper straightening means 3 is activated by a control signal to that effect from the microcomputer 2.
By applying pressure to the passive paper feed roller 5a by one pressure variable means 4a, one end of the paper is prevented from advancing, and the other end of the paper advances as usual.
The paper as a whole moves forward in the direction to eliminate the misalignment, and the misalignment is corrected. Further, as shown in FIG. 5(b), if the paper has shifted downward in the drawing, the paper straightening means 3 applies pressure to the paper feed roller 5b using the pressure variable means 4b, and similarly Correct the misalignment.

Next, FIG. 6 shows a flowchart of a program that performs such operations.

First, in step S1, it is determined whether or not to start copying. Then, if the copy has not started, the process returns to the previous state, and if the copy has started, the process proceeds to the next step. Next, the pressure variable means 4a, 4b are turned off so that the paper feed rollers 5a, 5b are in the standard pressurized state (step S2, step S3). and,
In step S4, it is checked whether the photosensor la of the transmission type photosensors serving as the paper misalignment detection means 1 is turned on. If it is not turned on, the paper is blocking the light, so the paper has shifted downward in the drawing as shown in FIG. 5(b), and in step S5, the pressure variable means 4b (This corrects paper misalignment as described above.) Further, if the photo sensor 1a is turned on in step S4, there is no paper misalignment, so the process advances to step S6, and before that, the pressure variable means 4b
If it was on, turn it off because the error has now been fixed. Then, the process advances to step S7 to check whether the photosensor 1b is turned on. And if it's not on, as mentioned above (
(See Figure 5(a)) Since there is a misalignment, step S
At step 8, the pressure variable means 4a is turned on. Further, if the photosensor 1b is on, the process advances to step S9, and in step S9, if the photo sensor 1b is on by then, the pressure variable means 4a is turned on.
is off. Then, repeat the same process thereafter. However, if the paper is conveyed continuously, step S is performed at first.
The process proceeds from step S10, but from the second sheet, it starts from LOOP in step S10.

In this embodiment, the paper feed roller 5 of the paper straightening means 3 is
Although it is a driven type and does not rotate by itself, it is also possible to use a drive type paper feed roller 5 that rotates by itself.

In that case, by connecting a motor to the paper feed roller shaft 31 of the pressure variable means 4 shown in FIG.
can be driven type. Here, in this example,
When the paper feed roller 5 is a driven type, the pressure variable means 5
Although the rotation of the paper feed roller 5 is slowed down when pressure is applied to the paper feed roller 5, if the paper feed roller 5 is of a drive type,
Conversely, applying pressure may speed up the rotation. Therefore, the paper feed roller 5 will be explained in detail separately for a driven type and a driven type.

First, in the case of the driven type, when the paper and the paper feed roller 5 are far apart, the roller is stationary, but when the paper is in slight contact with the paper, the advance of the paper is delayed, and the roller rotates with some slip, applying a little more pressure. This eliminates the roller slip, but the rotation of the reroller slows down. Next, in the case of a drive type, it is assumed that the number of rotations of the roller is faster than the advancing speed of the paper (on the contrary, if it is slower, the advancing speed of the paper will be slowed accordingly). When the roller and paper are slipping, there is no effect on the paper, and if you apply a little more pressure to the roller, the rotation of the roller is transmitted to the paper and the paper advances faster, and if you apply even more pressure, the roller will not rotate. The paper progresses slowly. Therefore, in the case of a drive type, depending on the strength of the pressure applied by the pressure variable means, the paper may advance faster or slower, so for example, in the case of a pair of rollers, it is necessary to reverse the rollers applying pressure. .

Further, in this embodiment, two paper misalignment detection means 1 are attached to the paper storage section 11, but the number is not limited to two, and a plurality of paper misalignment detection means 1 may be used to detect paper misalignment. . Also, considering the case where there are many types of paper sizes, when using the manual feed tray (paper storage section) described in this embodiment, one sheet is placed on the left and right in the direction of paper movement for each paper size. A displacement detection means may be provided, and the paper displacement detection means may be turned on according to the selected paper size to detect paper displacement.

Furthermore, in this embodiment, transmissive type photosensors as paper misalignment detection means are provided at the ends of paper width direction regulation kites just outside the regular paper placement locations, and when the light receiving elements are receiving light, The paper is located in the correct position, and when no light is received, the paper is assumed to be misaligned. When the light-receiving element does not receive light, it assumes that the paper is in the correct location, and when it receives light, it assumes that the paper is misaligned and detects the misalignment of the paper. You can do it like this. In addition, in this embodiment, when a reflective photosensor is used as the paper misalignment detection means, this reflective photosensor is placed just outside the regular paper placement location at the tip of the paper width direction regulation guide in the paper storage section. If the light receiving element does not receive light,
If the paper is in the correct position and the light is received, it is assumed that the paper is misaligned and the paper has detected the misalignment. It is installed just inside the paper placement area, and when the light-receiving element does not receive light, it assumes that the paper is in the correct location, and when light is received, the paper is misaligned, and detects the misalignment of the paper. You can.

Further, in the present embodiment, the paper feed roller is used as the roller of the paper straightening means 3, but the paper feed roller may not be provided separately, it may be a conveyance roller, or another roller may be used.

Further, the paper conveyance mechanism of the present invention can be used not only for image forming apparatuses but also for other apparatuses for conveying paper or sheets.

[Effects of the Invention] In the present invention, the paper misalignment detection means detects paper misalignment, the control means emits a predetermined control signal based on the detection result, and the paper correction means emits a predetermined control signal based on the control signal. hand,
Since paper misalignment is corrected, paper thickness, paper properties, size,
Even if the paper is in a different state, misaligned paper can be automatically and reliably corrected.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the paper transport mechanism according to the present invention, FIG. 2(a) is a plan view of the vicinity of the paper storage section of the embodiment, and FIG. 2(b) is a transparent view of the embodiment. 2(c) is a schematic side view of a reflective type photosensor of the same embodiment, FIG. 3 is a side view of an example of the pressure variable means of the same embodiment, FIGS. 4(a) and (b) are side views of other examples of the pressure variable means of the same embodiment, and FIGS. 5(a) and (b)
6 is a plan view of the vicinity of the paper storage unit in the case where paper is misaligned in the same embodiment, FIG. 6 is a flowchart of the same embodiment, and FIG. 7 is a plan view of the vicinity of the conventional registration roller. 1... Paper displacement detection means, 2... Control means, 3...
-Paper correction means, 4.4a, 4b...pressure variable means.

Claims (1)

[Claims] In a paper transport mechanism that transports paper, a paper shift detection means detects a shift of the paper when the paper is not in a normal position, and a predetermined control signal is generated based on the detection result of the paper shift detection means. a control means, a roller and
a pressure variable means for controlling the roller in accordance with a predetermined control signal of the control means to change the pressure of the roller applied to the paper, and a paper correction means for correcting misalignment of the paper. A paper conveyance mechanism characterized by: