JP3744745B2 - Paper feeding method and recording apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus such as a printer, and in particular, a distance between a recording head and a sheet during a skew removing operation for correcting skew by abutting a sheet fed by a sheet feeding roller against a conveying roller and / or before starting recording. The present invention relates to a sheet feeding method and a recording apparatus that achieve noise reduction with respect to a sound caused by a slip between a sheet feeding roller and a sheet that occurs during a cueing operation for setting the value to a specified value.
[0002]
[Prior art]
Conventional paper feeders generally employ a system in which a plurality of sheets stacked on a hopper are fed one by one from the topmost sheet, and a separation pad that contacts the paper feed roller is fed to the feed path. And the sheets are fed one by one using the friction between the separation pad and the paper.
In the method of feeding sheets one by one from the hopper, a so-called skew that is sent obliquely with respect to the feeding path is likely to occur. If the paper is fed in a skewed state, the paper is likely to be jammed, and a problem such as the fact that printing is not performed at a predetermined position of the paper occurs. As a countermeasure, skew removal is performed before recording. For skew removal, the front end of the paper is abutted against the stopped transport roller and the paper feed roller is rotated for a short time in that state, the transport roller is bitten, and the transport roller is stopped with the paper feed roller stopped. There is a biting discharge system that reverses and discharges.
Further, in order to align the printing positions of the recording head and the paper, the paper is cued to a certain length between the conveying roller and the recording head after the skew is removed. The cueing of the sheet is accurately performed by the rotation control of the conveying roller, but at the same time, the rotation control for causing the sheet feeding roller to stand by to the reset position is performed.
[0003]
[Problems to be solved by the invention]
As described above, the conventional abutting type skew removal is performed by rotating only the paper feed roller in a state where the paper feeding is stopped. Also, in the cueing process, after the skew removal is completed, the feeding roller is further rotated to make just one rotation and wait for the reset position in the preceding stage of the cueing process. Since there is a relationship that the amount <the feed amount until the paper feed roller is reset, the transport roller is stopped before the paper feed roller reaches the reset position. As a result, the sheet feeding is stopped, but the rotation of the sheet feeding roller to the reset position is continued as described above. In this way, when only the paper feed roller rotates in the paper feeding stop state, slippage between the paper and the paper is likely to occur. In particular, when performing high-quality printing (recording) similar to a photograph, slipping is more likely to occur because paper with a coated surface and generally stiff paper is often used. Since the sound accompanying the slip that occurs between the paper feed roller and the paper is easy to feel as noise, a countermeasure against noise reduction has been desired.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding method and a recording apparatus in which noise is reduced with respect to a sound accompanying a slip between a paper feeding roller and a paper that occurs during a skew removing operation and / or a cueing operation.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, the paper fed by the side-viewing D-type paper feed roller is abutted against the transport roller while abutting against a separation pad that can separate the multi-fed paper, and then the paper is skewed. In the paper feeding method in which feeding is performed by a roller, the paper feeding speed at the time of the abutting operation is set to be higher than a normal paper feeding speed, the paper is abutted against the conveying roller, and skew is removed. In operation, the conveyance roller is rotated synchronously with the rotation to the reset position where the chord portion of the side-view D-type feed roller faces the separation pad, and then the fixed length cueing is performed. Features.
According to the first aspect of the present invention, the transport roller is rotated synchronously until the paper feed roller is stopped at the reset position, and then the paper is cued for a certain length. Therefore, the slip between the paper feeding roller that rotates to the reset position after the skew removal by the synchronous rotation and the paper is eliminated, and no noise is generated.
[0006]
Further, according to the first aspect of the present invention, when skew removal is performed by the high speed rotation of the paper feed roller, the generation of sound due to slip occurring between the paper feed roller and the paper after the paper strikes the transport roller is temporal. It can be kept short, making it difficult to feel noise.
[0007]
According to a second aspect of the present invention, in the first aspect of the present invention, the sheet is detected between the paper feed roller and the transport roller, and switching to high speed is performed by the detection signal.
According to the invention of claim 2, by changing the speed of the paper feed roller at a position close to the transport roller, the influence of manufacturing variations between the paper feed roller and the transport roller can be reduced, and The hitting accuracy can be increased, and switching to high-speed feed can be easily realized with a control structure.
[0008]
According to a third aspect of the present invention, in the first or second aspect of the invention, the control of the paper feed roller and the conveyance roller is performed by selecting a high image quality output mode.
According to the third aspect of the present invention, in the high-quality output mode in which printing (recording) is performed in the same manner as a photograph, stiff paper is often used. Therefore, if the paper feed roller rotates while the paper is stopped, the slip occurs. However, if the paper feed roller is switched at a high speed during the skew removal operation, or the synchronous rotation is performed during the cueing operation, in other words, the amount of advancement is increased so that the gap between the paper feed roller and the paper is increased. By performing control to prevent slipping, the slip noise of the paper feed roller can be reduced or eliminated in the skew removal operation and / or cueing operation, and the noise level in a specific mode can be effectively reduced. Lowers the noise level.
[0009]
According to a fourth aspect of the present invention, in the first or second aspect of the invention, the control of the paper feed roller and the conveyance roller is performed by selecting a paper type.
According to the invention of claim 4, when using a stiff sheet, the same effect as that of claim 3 can be obtained.
[0010]
According to a fifth aspect of the present invention, there is provided a paper feeding roller for rotating a paper feeding roller in a recording apparatus that performs recording by feeding the paper fed by the paper feeding roller and abutting against the paper feeding roller to remove the skew. A driving means; a conveying roller driving means for rotating the conveying roller; and a control means for controlling the paper feeding roller driving means and the conveying roller driving means. The control means feeds faster than the normal paper feeding speed during the abutting operation. It has a high-speed mode for changing the paper speed, and the high-speed mode can be switched.
According to the fifth aspect of the present invention, since the mode can be switched to the high speed mode, it is easy to adapt to the use environment in which the noise level during feeding is important.
[0011]
The invention of claim 6 is characterized in that, in the invention of claim 5, a means is provided for the user to select the high speed mode.
According to the sixth aspect of the present invention, the user can select the high-speed mode, which is convenient when quiet feeding is desired or when the discomfort is reduced for a person who easily feels a slip noise.
[0012]
According to a seventh aspect of the present invention, in the fifth or sixth aspect of the invention, a paper detector that detects paper is disposed between the paper feed roller and the transport roller, and the control means is configured to detect the paper according to a detection signal of the paper detector. It is characterized by switching to high speed.
According to the invention of claim 7, by changing the speed of the paper feed roller at a position close to the transport roller, it is possible to reduce the influence due to the manufacturing variation between the paper feed roller and the transport roller, and to push the transport roller. The hitting accuracy can be increased, and switching to high-speed feed can be easily realized with a control structure.
[0013]
According to an eighth aspect of the present invention, in the invention according to any one of the fifth to seventh aspects, the control unit performs the control of the paper feed roller and the conveyance roller by selecting a high image quality output mode.
According to the eighth aspect of the present invention, since a stiff sheet is often used in the high image quality output mode in which printing (recording) is performed in the same manner as a photograph, slipping occurs when the sheet feeding roller rotates while the sheet is stopped. However, if the paper feed roller is switched at a high speed during the skew removal operation, or the synchronous rotation is performed during the cueing operation, in other words, the amount of advancement is increased so that the gap between the paper feed roller and the paper is increased. By performing control to prevent slipping, the slip noise of the paper feed roller can be reduced or eliminated in the skew removal operation and / or cueing operation, and the noise level in a specific mode can be effectively reduced. Lowers the noise level.
[0014]
According to a ninth aspect of the present invention, in the invention according to any one of the fifth to seventh aspects, the control means performs the control of the paper feeding roller and the conveying roller by selecting a paper type.
According to the ninth aspect of the present invention, when a stiff sheet is used, the same effect as in the third aspect can be obtained.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a main part of a recording apparatus according to the present invention.
First, an outline of skew removal and cueing will be described with reference to FIG. The sheet feeding device ASF has a function of feeding a plurality of stacked sheets P one by one. As a main configuration, the hopper 1 that stacks and sets a plurality of sheets P, and the topmost hopper 1 are provided. A paper feed roller 2 that picks up and feeds the paper P one by one and a separation pad 3 that separates the paper that is double-fed together with the uppermost paper P are provided. The paper feed roller 2 has a D-shape when viewed from the side, and a sheet of paper P passes through the paper guide 8 and is conveyed while rotating once in a contact state between the arc portion of the paper feed roller 2 and the separation pad. 4 is fed. The transport roller 4 performs skew removal of the paper P. The skew removal is an abutting method in which the paper P is abutted against the stopped conveyance roller 4.
[0016]
After the skew removal, the transport roller 4 performs a cueing operation with a fixed length by the cooperative action with the driven roller 5 and then sends the paper P to the area of the recording head 6 in accordance with the recording timing to perform recording. The recorded paper P is discharged by the discharge roller 7. The above is an outline.
[0017]
Next, in order to make the explanation easy to understand, a conventional mechanism for generating the slip noise will be specifically described with reference to FIGS.
In the abutting method, as shown in FIG. 2, the skew is corrected by applying a force to advance the sheet P abutted against the transport roller 4 stopped by the rotation of the sheet feeding roller 2. When the rotational force of the paper feed roller 2 is applied to the paper P whose advance is stopped by the transport roller 4, the paper P is bent between the transport roller 4 and the paper feed roller 2 in the case of a paper P having a low stiffness such as plain paper. Slipping does not occur. However, since there are many papers P that are intended for high-quality output such as photo print paper, the paper P is difficult to bend and the recording surface is subjected to gloss processing. Slip easily occurs during When the paper feed roller 2 slips, a slip noise is generated.
[0018]
Further, the cueing of the paper P after the skew removal is performed by setting the paper P at the recording start position, and is performed by controlling the rotation of the paper feed roller 2 and the transport roller 4. In FIG. 3, when the cueing operation is started, first, the conveying roller 4 rotates forward to feed the paper P by a predetermined length L (hereinafter referred to as “advance” before the final cueing). During this time, the paper feed roller 2 also rotates forward in the same manner as the transport roller 4, but the transport roller 4 stops when the feed amount L is sent. On the other hand, in order to make the paper feed roller 2 stand by at the reset position, it is necessary to further rotate the paper feed roller 2 forward to a position where the string portion 2a of the paper feed roller 2 faces the separation pad 3. At this time, since the paper P is in a feed stop state due to the rotation of the transport roller 4 being slipped, a slip occurs between the paper feed roller 2 and the paper P, and a slip noise is generated. The above is the conventional mechanism for generating slip noise.
[0019]
In order to silence the slip noise (first noise) at the time of skew removal and the slip noise (second noise) at the time of cueing, the present embodiment reduces the time during which the first noise is generated and By not generating noise, the overall noise level during feeding is reduced. FIG. 4 is an explanatory view of the skew removal operation according to the present invention, FIG. 5 is an explanatory view of the forward movement operation according to the present invention, and FIG. 6 is an explanatory view of the reverse feed (1) and reverse feed (2) operations following the forward movement. FIG. 7 is an explanatory diagram of the final cueing operation, and FIG. 8 is a paper feed control block diagram.
[0020]
First, paper feed control will be described with reference to FIG. The control unit 10 receives print information sent from a print driver of a main control unit or the like (not shown) of the recording apparatus, determines the print information, and determines a plurality of paper feeds prepared in advance from the determination result. Select and execute from the sequence. The print information includes information on paper types (paper type information) such as plain paper, coated paper, OHP sheets, glossy paper, and glossy film, information on resolution (resolution information), and the like. The paper feed sequence is an operation of rotating the paper feed roller 2 and the transport roller 4 at a normal paper feed speed V ₀ , and the paper feed roller 2 at a paper feed speed (high speed mode) V ₁ faster than the normal paper feed speed V _0. It is configured by a combined operation such as an operation of rotating, an operation of rotating the paper feed roller 2 and the transport roller 4 forward and backward at a normal paper feed speed. When the user can select the high-speed mode, the control unit 10 is provided with a switch (not shown) as high-speed mode selection means, and is configured to enter the high-speed mode by an operation signal of this switch. The control unit 10 is preferably configured to determine at least the paper type.
[0021]
The control unit 10 controls the paper feed roller drive unit 11 and the transport roller drive unit 12 based on the paper feed sequence selected by the paper feed command. The paper feed roller drive unit 11 is composed of a paper feed roller motor such as a stepping motor, and the paper feed roller motor is operated at a normal feed speed V ₀ or a high speed (V) based on a drive signal from the control unit 10. ₁ ) Drive in mode. The conveyance roller drive unit 12 is configured by a conveyance roller motor such as a DC motor or a stepping motor, and is driven to feed the paper P in the direction of the recording head 6 based on a drive signal from the control unit 10. Or drive in the opposite direction.
[0022]
The sheet feeding operation according to the present embodiment in the high image quality output mode will be described with reference to FIGS. 4 to 7 and FIGS. 9 to 12. As for the rotation direction of the paper feed roller 2, the clockwise rotation shown in FIGS. 4 to 7 is referred to as “forward rotation”, and the rotation in the opposite direction is referred to as “reverse rotation”. In the direction, a clockwise rotation in the figure is referred to as “reverse rotation”, and a rotation in the opposite direction is referred to as “forward rotation”. 11 and 12 show a conventional paper feeding operation for comparison.
[0023]
The skew removal is performed as follows. Since the distance between the paper detector PE and the transport roller 4 is known, the rotation amount of the paper feed roller 2 necessary for abutting the front end of the paper P against the transport roller 4, that is, the number of steps (<n1), is determined in advance. Since it is known, by rotating the number of steps by adding the α step to the number of steps (n1 steps), a force that pushes the paper P forward after hitting the conveyance roller 4 acts, and the skew removal is performed. Done.
[0024]
During the reset operation of the paper feed roller 2, the rotation angle (ASF phase) of the paper feed roller 2 is detected by a phase detector (not shown) including an encoder provided on the paper feed roller shaft, for example. The phase detector outputs an open signal at the string portion 2 a of the paper feed roller 2 and a close signal at the arc portion of the paper feed roller 2. In order to make the reset position of the feed roller 2 coincide with the initial position (center) of the ASF phase detection of the phase detector, the feed roller 2 is rotated forward in FIGS. 9 to 12 and supplied by the open signal of the phase detector. The paper roller 2 is further rotated forward by n2 steps. Here, the above-described series of steps (feed roller normal rotation → phase detection “open” → feed roller n2 steps normal rotation) performed after the n1 steps forward rotation of the paper feed roller 2 is referred to as a “reset operation”.
[0025]
When the sheet feeding operation is started, the sheet feeding roller 2 rotates forward and picks up and feeds only the uppermost sheet P of the hopper by cooperation with the separation pad 3. When the front end of the paper P is detected (paper present) by the paper detector PE shown in FIG. 4A, in the present embodiment, the paper feed roller 2 is fed to the normal paper feed up to that time based on this signal. The feeding speed is switched to the feeding speed V ₁ (V ₁ > V ₀ ), which is faster than the speed V ₀ , and the n1 steps are rotated forward. Leading edge of the sheet P passing through the sheet detector PE is abuts against the conveying roller 4 as shown in FIG. 4 (B), the skew removal is performed by further be forward in the sheet feeding speed V _1.
[0026]
In the conventional skew removal, as shown in FIGS. 11 and 12, since the normal rotation of n1 steps is performed at the normal sheet feeding speed V ₀ , the slip noise between the sheet feeding roller 2 and the sheet continues for a long time as noise. It becomes easy to feel. On the other hand, in the skew removal of this embodiment, normal rotation of n1 steps is performed at a high speed V ₁ , and therefore, accompanying the slip that occurs between the paper feed roller 2 and the paper P after the paper P is abutted against the transport roller 4. Generation of the first noise can be suppressed in a short time.
[0027]
Subsequently, when the cueing operation is started, the conveyance roller 4 is rotated in synchronization with the rotation of the reset operation of the paper feed roller 2 as shown in FIG. 5, that is, the conveyance roller 2 is conveyed until it stops at the reset position. The rotation of the roller 4 is continued, and the sheet P is advanced from the transport roller 4 by a length L1. As shown in FIGS. 9 and 10, the advance length L1 is equal to the number of steps (m1 +) of the transport roller 4 corresponding to the number of steps of the paper feed roller 2 for the paper feed roller 2 to rotate forward to the reset position. determined by m4). Thereafter, as shown in FIGS. 6A, 9 and 10, in a state where the paper feed roller 2 is stopped at the reset position, only the transport roller 4 is reversely rotated by m5 steps to slightly reverse the paper. In this reverse feed, the paper feed roller 2 and the transport roller 4 are simultaneously reversely reversed and further reversely fed, and then the paper feed roller 2 and the transport roller 4 are simultaneously forwardly rotated until the cueing is completed. This operation is necessary to set 2 to the reset position.
[0028]
After the paper P is reversely fed only by the transport roller 4, as shown in FIGS. 6B, 9 and 10, the paper feed roller 2 is reversed by n3 steps, and at the same time, the transport roller 4 is reversed by m2 steps. Since n3 and n2 are the same as the feed amount, slip does not occur. Subsequently, as shown in FIG. 7, the paper feed roller 2 is reset, and the transport roller is rotated forward by m3 steps, the front end of the sheet is set at a normal cueing position, and cueing is completed.
[0029]
In this way, by inserting the step of leading the paper P by L1 longer than the conventional fixed length L (FIG. 3), that is, normal rotation to the reset position of the paper feed roller 2 and normal rotation of the transport roller 4 Are synchronized, and both rollers 2 and 4 are stopped at the same time, so that slip between the paper feed roller 2 and the paper P is eliminated and second noise is not generated.
[0030]
In the output mode at the normal paper feed speed V ₀ typified by plain paper, even when the paper feed roller 2 rotates to the reset position in the stop state of the paper P, the paper feed roller 2 and the paper P are not connected. In this part, since the paper feed continues and the paper is easily bent when it is pressed and slip does not easily occur, high-speed switching at the time of skew removal and L1 advancement are not performed.
[0031]
In this embodiment, the high-speed switching timing is performed at the time of paper detection by the paper detector PE in the high image quality output mode, but it is sufficient that the paper P is switched at high speed until it hits the transport roller 4. Further, it may be switched at a high speed from the time when the paper feed roller 2 picks up the paper P.
[0032]
【The invention's effect】
According to the present invention, the skew removal operation is performed by the high speed rotation of the paper feed roller, so that the generation of a sound due to slip occurring between the paper feed roller and the paper after the paper hits the transport roller can be suppressed in a short time. It becomes difficult to feel noise.
Further, in the cueing operation, the conveyance roller is rotated synchronously until the paper feed roller is stopped at the reset position, and then a fixed length cueing is performed, thereby eliminating slip between the paper feed roller and the paper and generating no noise.
[Brief description of the drawings]
FIG. 1 is a side view showing a main part of a recording apparatus according to the present invention.
FIG. 2 is an explanatory diagram of a conventional skew removing operation by a butting method.
FIG. 3 is an explanatory diagram of a conventional cueing operation.
FIGS. 4A and 4B illustrate a paper feeding operation up to the end of skew removal according to the present invention, in which FIG. 4A is an explanatory diagram of paper detection, and FIG.
FIG. 5 is an explanatory diagram of L1 advance operation after skew removal according to the present invention.
6 shows the reverse feed operation after the forward and reset operations of FIG. 5, where reverse feed (1) is an explanatory diagram for returning m5 steps, and reverse feed (2) is an explanatory diagram for returning m2 steps and n3 steps. .
7 is an explanatory diagram of a final cueing operation by forward rotation after the reverse feeding operation of FIG. 6. FIG.
FIG. 8 is a paper feed control block diagram according to the present invention.
FIG. 9 is a diagram illustrating a sheet feeding flow according to the present exemplary embodiment.
FIG. 10 is a diagram illustrating a sheet feeding timing chart according to the present exemplary embodiment.
FIG. 11 is a diagram illustrating a conventional paper feed flow.
FIG. 12 is a diagram illustrating a conventional paper feed timing chart.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hopper 2 Paper feed roller 3 Separation pad 4 Carrying roller 5 Driven roller 6 Recording head 7 Discharge roller 8 Paper guide P Paper PE Paper detector ASF Paper feed device

Claims (9)

The paper fed by the side-view D-type feed roller abuts against the transport roller while abutting against the separation pad that can separate the multi-feed paper, and after the skew is removed, the paper is fed by the transport roller. In paper method,
The paper feeding speed at the time of the abutting operation is made faster than the normal paper feeding speed to abut against the transport roller to perform skew removal,
At the time of the cueing operation after the skew removal, the conveying roller is rotated synchronously with the rotation to the reset position where the chord portion of the side-view D-type feed roller faces the separation pad, and then the fixed length Feeding method, wherein cueing is performed.  2. The paper feeding method according to claim 1, wherein the paper is detected between the paper feeding roller and the conveying roller, and switching to high speed is performed by the detection signal.  3. The paper feed method according to claim 1, wherein the control of the paper feed roller and the transport roller is performed by selecting a high image quality output mode.  3. The paper feeding method according to claim 1, wherein the control of the paper feeding roller and the conveying roller is performed by selecting a paper type. In the recording apparatus for feeding and recording by the transport roller after the paper fed by the paper feed roller is abutted against the transport roller and skewed,
Paper feed roller driving means for rotating the paper feed roller;
Conveying roller driving means for rotating the conveying roller;
Control means for controlling the paper feed roller driving means and the transport roller driving means,
The recording apparatus according to claim 1, wherein the control unit has a high-speed mode in which a paper feed speed is higher than a normal paper feed speed during the abutting operation, and the high-speed mode is switchable.  6. The recording apparatus according to claim 5, further comprising means for a user to select the high speed mode.  7. A sheet detector for detecting a sheet is disposed between the sheet feeding roller and the conveying roller, and the control means switches to the high speed by a detection signal of the sheet detector. The recording device described.  The recording apparatus according to claim 5, wherein the control unit performs the control of the paper feed roller and the conveyance roller by selecting a high image quality output mode.  The recording apparatus according to claim 5, wherein the control unit performs the control of the paper feed roller and the conveyance roller by selecting a paper type.

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