JP2653736B2 - Paper suction control method for printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic sheet feeding mechanism for feeding cut sheets by rotation of a hopping roller, and the cut sheet fed by the automatic sheet feeding mechanism to a predetermined position on a printing position side. The present invention relates to a paper suction control method for a printer having a feed roller.

[0002]

2. Description of the Related Art FIG. 4 is a layout diagram of a main part of an example of a horizontal printer to which a conventional paper suction control method is applied.
In FIG. 4, in the printer 100, the cut sheet 4 passes through a print position 3 where the platen 1 and the print head 2 are arranged to face each other, and a paper path is formed before and after the print position 3. Paper guide 24 is provided. In the middle of the paper guide 24, a feed roller 5, a first roller 6, a second roller 7, and a discharge roller 8 are provided in a pair so as to sandwich the paper path from above and below. Further, a stacker 9 is provided at a discharge side end of the paper path, and an automatic paper feed mechanism 10 is mounted at a feed side end. In addition, a sensor 11 is provided at a position on the sheet path immediately before the feed roller 5 to detect that the cut sheet 4 has been fed, and a sensor 11 on the sheet path immediately after the first roller 6 is provided. A cue sensor 12 for detecting that the cut sheet 4 has been sent is provided at the position.

Further, the automatic paper feed mechanism 10 corresponds to a base plate 13 on which a plurality of cut sheets 4 are stacked and set, and an upper end of one end of the base plate 13 adjacent to the feeding side of the paper path. A hopping roller 14 rotatably disposed, a coil spring 15 for applying a pushing force to the base plate 13 in a state where the cut sheet 4 on the base plate 13 is pressed against the hopping roller 14, and a pushing up of the coil spring 15 A lever 16 for switching the movement of the base plate 13 in the direction of arrows AB in FIG.
The brake shoe 23 and the like for separating the cut sheet 4 sent one by one.

FIG. 5 is a control block diagram of the printer shown in FIG. In FIG. 5, this control system is configured so that a detection signal from the sensors 11 and 12 and a trigger signal 18 from the device such as a host computer can be input to a control unit (CPU) 17. The control unit 17
Is connected to a first motor 20 via a first motor drive circuit 19 and to a second motor 22 via a second motor drive circuit 21. Of the first and second motors 20 and 22, the first
The motor 20 serves as a first drive source, and rotationally drives the hopping roller 14 in the automatic paper feed mechanism 10. On the other hand, the second motor 22 serves as a second drive source, and includes the feed roller 5, the first roller 6, the second
Is driven to rotate.

FIG. 6 is a time chart showing operation timings of main parts in the control system shown in FIG.
The paper suction operation of the printer shown in FIGS. 4 and 5 will now be described with reference to this time chart.

First, the lever 16 is operated to move the base plate 13 in the direction of arrow A in FIG. 4 by the pushing force of the coil spring 15, and the cut sheet 4 on the base plate 13 is pressed against the hopping roller 14 and set.

In this state, when a trigger signal 18 is input to the control unit 17 from the host computer, the first motor 20 is driven to rotate via a first motor drive circuit 19, and the first motor 20 Hopping roller 1
Rotate 4. Then, the cut sheet 4 is sent to the feed roller 5 side by the frictional force generated between the hopping roller 14 and the cut sheet 4. When the cut sheet 4 is fed by the hopping roller 14, the cut sheet 4 is separated one by one by the brake shoes 23, and only the top cut sheet 4 is sent out.

The cut sheet 4 sent to the feed roller 5 passes over a sheet guide 24 and strikes the feed roller 5 in the printer. The detection of the collision of the cut sheet 4 with the feed roller 5 is detected by the sensor 11, and a signal is input to the control unit 17. Then, the rotation driving of the first motor 20 is stopped, and at the same time, the rotation of the hopping roller 14 is stopped. On the other hand, contrary to the stop of the first motor 20, a second motor 22 is rotationally driven via a second motor drive circuit 21, and the feed roller 5 and the first roller 6, the second roller 7 rotates. Then, the cut sheet 4 is sequentially fed to the printing position 3 by the rotation of the feed roller 5 and the first roller 6. When the cue sensor 12 detects that the cut sheet 4 has been sent to the printing position 3, the rotation of the second motor 22 is stopped, and the feed rollers 5 and 5 are turned off.
Each rotation of the first roller 6 and the second roller 7 temporarily stops, and a printable state is set. Subsequently, the printing operation starts. This printing operation is performed while the print head 2 mounted on the carriage frame 25 is moved along with the carriage frame 25 by a driving source (not shown) on a shaft 26 on which the carriage frame 25 is supported. At the time of printing, a line feed is performed by means not shown. Then, after all printing is completed, the sheet is discharged to the stacker 9 and waits for receiving the trigger signal 18 again. After receiving the trigger signal 18, the same operation is repeated.

[0009]

However, the above-described conventional paper suction control method has the following problems.
That is, in the cut sheet handled by this type of printer, the end of the sheet may be curled (curved) due to the cutting method or the environment as a problem of the sheet itself, and the curled cut sheet is fed. In some cases, the leading edge of the sheet abuts on the outer peripheral surface of the roll without being sucked between the pair of feed rollers, and the cut sheet may not be conveyed even if the feed roller rotates. In general, the cut sheet 4 having a large continuous paper amount has a large rigidity of the sheet itself.
In some cases, the cut sheet was not conveyed even when the feed roller was rotated and the feed roller rotated in the same manner as described above without being sucked in between. Further, even when the leading end of the sheet is sucked between the pair of feed rollers, if the load from the cut sheet 4 is large, the feed roller 5 alone cannot provide a sufficient feeding force, and the sheet is misaligned at both ends. Print misalignment (skew) may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a paper suction control method that always enables reliable paper suction.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has an automatic paper feed mechanism for feeding cut sheets by rotation of a hopping roller and a cut sheet fed by a hopping roller. A pair of feed rollers for feeding the paper to a predetermined position on the printing position side, a first drive source for rotating and driving the hopping roller, and a pair of feed rollers for driving the pair of feed rollers driven independently of the hopping roller A second drive source, a first sensor disposed on the paper suction side of the pair of feed rollers, and a first sensor for detecting that the leading end of the cut sheet has reached the position of the pair of feed rollers. A second sensor disposed on the sheet discharge side of the feed roller and detecting that the leading end of the cut sheet has reached a predetermined position after passing through the pair of feed rollers; and a first sensor and a second sensor. A control unit for controlling the first and second drive sources based on these signals, wherein the rotation of the pair of feed rollers is stopped and the first sensor is turned off. Based on the detection signal, the hopping roller is rotated until the leading end of the cut sheet hits the pair of feed rollers, and then the rotation of the hopping roller is stopped for a predetermined time. The hopping roller and the pair of feed rollers are simultaneously rotated in a state in which the paper feed amount is set to be larger than that in the above, and after the second sensor detects the leading end of the cut sheet, the rotation of the hopping roller is stopped and The cut sheet is conveyed by the rotation of the feed roller.

[0012]

In the above-described method of controlling paper suction of the printer,
While the rotation of the pair of feed rollers is stopped, the hopping roller is rotated based on the detection signal from the first sensor until the leading end of the cut sheet hits the pair of feed rollers, and then the rotation of the hopping roller is stopped. Since the stop is performed only for the time, the leading end of the cut sheet fed by the hopping roller is always hit by a pair of feed rollers that are stopped rotating. Therefore, even when so-called skew occurs when the cut sheet is fed obliquely at the time of feeding the sheet by the hopping roller, the skew of the cut sheet is corrected by abutting against the stopped feed roller. After the rotation of the hopping roller is stopped as described above, the hopping roller and the pair of feed rollers are simultaneously rotated with the paper feed amount of the hopping roller set to be larger than the paper feed amount of the pair of feed rollers. As a result, the cut sheet is loosened on the sheet suction side of the feed roller due to the difference between the sheet feed amounts. At this time, even if the leading end of the cut sheet fed by the hopping roller is in contact with the outer peripheral surface of the feed roller, the cut sheet is forcibly pushed out to the feed roller side by the restoring force of the sheet itself due to the slack described above. In addition, since the leading edge of the sheet is guided between the pair of feed rollers (roller contact portion) with the rotation of the feed roller, the leading edge of the cut sheet can be reliably caught between the pair of feed rollers and sucked. . Further, even when the leading edge of the sheet is sucked between the feed rollers, the feed roller feeds the cut sheet by the hopping roller, so that a sufficient feeding force can be obtained with respect to the load of the cut sheet. In addition, after the second sensor detects the leading end of the cut sheet, the rotation of the hopping roller is stopped, so that the cut sheet is not unnecessarily slackened on the sheet suction side of the feed roller. In addition, the cut sheet can be sent out from the sheet discharge side of the feed roller in a state where the above-described slack is completely eliminated.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a control circuit block diagram of a horizontal printer 50 to which a paper suction method according to an embodiment of the present invention is applied, and FIG. In FIGS. 1 and 2, the same reference numerals as those in FIGS. 4 and 5 denote the same components as those in FIGS. 4 and 5.

A significant difference between the configuration of the present invention shown in FIGS. 1 and 2 and the conventional printer shown in FIGS. 4 and 5 is that in the configuration of the present invention, a sensor is provided immediately after the feed roller 5. In other words, a signal from the sensor 31 is input to the control unit 17, and the operation timing of the hopping roller 14 is controlled by a method different from that of a conventional printer. FIG. 3 shows the operation timing together with the operation timings of other main parts.

The paper suction operation of the printer shown in FIGS. 1 and 2 will be described next with reference to the timing chart of FIG.

First, the lever 16 is operated, the base plate 13 is moved in the direction of arrow A in FIG. 2 by the pushing force of the coil spring 15, and the cut sheet 4 on the base plate 13 is pressed against the hopping roller 14 and set.

In this state, when a trigger signal 18 is input from the host computer to the control unit 17, the first motor 20 is driven to rotate via the first motor drive circuit 19, and the first motor 20 Hopping roller 1
Rotate 4. Then, the cut sheet 4 is sent to the feed roller 5 side by the frictional force generated between the hopping roller 14 and the cut sheet 4. When the cut sheet 4 is fed by the hopping roller 14, the cut sheet 4 is separated one by one by the brake shoes 23, and only the top cut sheet 4 is sent out.

The cut sheet 4 sent to the feed roller 5 passes over the sheet guide 24 and strikes the feed roller 5 in the printer. The contact of the cut sheet 4 with the feed roller 5 is detected by a signal from the sensor 11, and the detection signal is input to the control unit 17.
Then, the driving of the first motor 20 is stopped for a predetermined time, and accordingly, the rotation of the hopping roller 14 is also stopped. During that time, the rotation of the feed roller 5 is kept stopped. Therefore, the leading end of the cut sheet 4 sent by the hopping roller 14 hits the feed roller 5 held in a stopped state. Thus, even when the cut sheet 4 is fed in a slanted state, the slant (skew) of the cut sheet 4 is reliably corrected by abutting against the feed roller 5 held in a stopped state. You. Here, the reason why the rotation of the hopping roller 14 is temporarily stopped as described above is that a time difference is provided between the rotation start timing of the feed roller 5 described later and the feed roller 5 in a state where the rotation is reliably stopped. Cut sheet 4
If the leading end of the cut sheet 4 hits while the feed roller 5 is rotating, the cut sheet 4 is sucked into the feed roller 5 without correcting the skew, and This is because the skew correction function as described above will not be performed.

Next, the first motor 20 is rotationally driven again via the first motor drive circuit 19, and the second motor 22 is rotationally driven again via the second motor drive circuit 21. The feed roller 5, the first roller 6, and the second roller 7 are rotated by the second motor 22. At this time, the hopping roller 14 driven by the first motor 20 feeds the cut sheet 4 and the second motor 2
The feed amount of the cut sheet 4 by the feed roller 5 driven by the feed roller 2 is set so that the feed amount by the hopping roller 14 is larger. This makes cut sheet 4
Is forcibly fed from the hopping roller 14 side to the feed roller 5 side, so that the cut sheet 4 is loosened during that time (the sheet suction side of the feed roller 5). At this time, since the cut sheet 4 is forcibly pushed out toward the feed roller 5 by the restoring force of the sheet itself due to the slack, even if the leading end of the sheet comes into contact with the outer peripheral surface of the feed roller 5, the cut sheet 4 is accompanied by the slack. Due to the pushing force and the rotational force of the pair of feed rollers 5, the leading end of the cut sheet 4 is reliably caught between the feed rollers 5 and sucked. When the cut sheet 4 is sucked between the feed rollers 5 and further fed to the printing position 3 by the feed roller 5, the leading end of the cut sheet 4 is detected by the sensor 31, and its signal is sent to the control unit 17. Is input to Then, the rotation drive of the first motor 20 is stopped, and at the same time, the hopping roller 1
The rotation of 4 stops. At this time, since the slack of the cut sheet 4 generated between the hopping roller 14 and the feed roller 5 starts to decrease, the slack of the cut sheet 4 does not become unnecessarily large. . After that, the cut sheet 4 is sequentially fed to the printing position 3 by the rotation of the feed roller 5 and the first roller 6. And
When the cue sensor 12 detects that the cut sheet 4 has been sent to the printing position 3, the rotation of the second motor 22 is stopped, and the feed roller 5, the first roller 6, and the second Each rotation of the roller 7 is stopped once, and the printing is enabled. Subsequently, the printing operation starts. This printing operation is performed by the print head 2 mounted on the carriage frame 25.
On a shaft 26 supporting the carriage frame 25,
It is performed by moving together with the carriage frame 25 by a driving source (not shown). At the time of printing, a line feed is performed by means not shown. When the printing operation for one page is completed and the cut sheet 4 is discharged to the stacker 9, the reception of the trigger signal 18 is again waited, and after receiving the trigger signal 18, the same operation as described above is repeated.

Therefore, in the printer 50 to which the method of controlling paper suction of the printer according to this embodiment is applied, the hopping roller 14 moves the cut sheet 4 through the feed roller 5 to a predetermined position on the printing position 3 side, that is, the first position. 2 and continues to rotate until detected by the sensor 31 of the feed roller 5.
, The feeding force is improved, and reliable feeding can always be performed. As a result, it is possible to reduce the occurrence of a jam and a print misalignment (skew) due to misalignment at both ends of the paper, which have conventionally been problems.

[0021]

As described above, according to the paper suction control method of the present invention, the rotation of the pair of feed rollers is stopped, and the leading edge of the cut sheet is detected based on the detection signal from the first sensor. Rotated the hopping roller until it hit a pair of feed rollers, and then stopped the rotation of the hopping roller for a predetermined time, so the tip of the cut sheet sent by the hopping roller was always
It is hit against a pair of feed rollers that have stopped rotating. Therefore, even if the so-called skew occurs when the cut sheet is fed obliquely at the time of feeding the sheet by the hopping roller, the skew of the cut sheet is surely corrected by abutting the stopped feed roller. Can be. Further, after the rotation of the hopping roller is stopped for a predetermined time, the hopping roller and the pair of feed rollers are simultaneously rotated in a state in which the paper feed amount of the hopping roller is set to be larger than the paper feed amount of the pair of feed rollers. As a result, the cut sheet loosens on the paper suction side of the feed roller, and the pushing force and the rotation of the pair of feed rollers causes the leading end of the cut sheet to be reliably caught between the pair of feed rollers. Can be inhaled. As a result, even when a cut sheet having high rigidity or a cut sheet having a curled leading end is fed, even if the leading end of the cut sheet comes into contact with the outer peripheral surface of the feed roller, the cut sheet is simply placed between the pair of feed rollers. It is possible to reliably inhale the vote paper. Further, even when the leading edge of the paper is sucked between the pair of feed rollers, the hopping roller assists the feeding of the cut paper by the feed roller, thereby providing a sufficient feeding force against the load of the cut paper. As a result, printing misalignment (skew) due to misalignment at both ends of the paper can be reliably prevented. In addition, after the second sensor detects the leading end of the cut sheet, the rotation of the hopping roller is stopped, so that the cut sheet is not unnecessarily slackened on the sheet suction side of the feed roller. , From the paper discharge side of the feed roller,
The cut sheet can be sent out in a state where the above-mentioned slack is completely eliminated. Therefore, it is possible to reliably prevent paper jam caused by slack of the cut sheet.

[Brief description of the drawings]

FIG. 1 is a control circuit block diagram of a printer to which a paper suction method according to an embodiment of the present invention is applied.

FIG. 2 is a main part configuration layout diagram of the printer shown in FIG.

FIG. 3 is a time chart showing operation timings of main parts of the printer shown in FIG.

FIG. 4 is a main configuration diagram showing an example of a printer to which a conventional paper suction method is applied.

FIG. 5 is a control circuit block diagram of the printer shown in FIG.

FIG. 6 is a time chart showing operation timings of main parts of the printer shown in FIG. 4;

[Explanation of symbols]

 Reference Signs List 3 printing position 4 cut sheet 5 feed roller 6 first roller 7 second roller 10 automatic paper feed mechanism 11 first sensor 14 hopping roller 17 control unit 21 first motor (first drive source) 22 2 motor (second drive source) 31 2nd sensor

Claims (1)

(57) [Claims] An automatic paper feed mechanism for feeding cut-sheet paper by rotation of a hopping roller; a pair of feed rollers for feeding the cut-sheet paper sent by the hopping roller to a predetermined position on a printing position side; A first drive source for rotationally driving a roller, a second drive source for rotationally driving the pair of feed rollers driven independently of the hopping roller, and a sheet of the pair of feed rollers A first sensor disposed on the suction side for detecting that the leading end of the cut sheet has reached the position of the pair of feed rollers; and a first sensor disposed on the sheet discharge side of the pair of feed rollers. A second sensor for detecting that the leading end of the cut sheet has reached a predetermined position after passing through the pair of feed rollers, and based on signals from the first and second sensors. And a control unit for controlling the first and second drive sources, wherein the detection signal from the first sensor is output in a state where the rotation of the pair of feed rollers is stopped. Then, the hopping roller is rotated until the leading end of the cut sheet hits the pair of feed rollers, and then the rotation of the hopping roller is stopped for a predetermined time. The hopping roller and the pair of feed rollers are simultaneously rotated in a state in which the hopping roller is set to be larger than the paper feed amount by the feed roller, and after the second sensor detects the leading end of the cut sheet, the hopping roller And stopping the rotation of the pair of feed rollers to convey the cut sheet. Control method.