JP2894951B2 - Printer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer device, and more particularly to an output printer device of a computer system which uses continuous paper as a medium and prints a large amount of data at high speed by a heater roll fixing system.

[0002]

2. Description of the Related Art In general, many printer apparatuses for outputting data from a computer are of an electrophotographic type using a continuous paper as a medium and having a high printing speed in order to rapidly process enormous data.

In such a printer device, a heater roller fixing system is used in which a heat roller is pressed against a printing surface to fix unfixed toner on the printing surface of the paper. In order to obtain the printing paper, the printing paper is warmed from the back surface by the preheater before being pressed against the heater roll.

FIG. 4 shows an overall configuration of an example of this type of electrophotographic printer, FIG. 5 shows a configuration of a main part of a fixing section thereof, and FIG. 6 shows a perspective view thereof.

[0005] In FIG. 4, a continuous paper 12 placed on a hopper section 13 is conveyed to an electrophotographic section 14 by a tractor section 16 and a toner image formed on a photoreceptor 15 is transferred.

[0006] The continuous paper 12 on which the toner image is laid is sent to the fixing unit 17 by the pressure roll 4, is thermally fixed, and is discharged to the stacker unit 18.

In FIGS. 5 and 6, the continuous paper 12 on which the toner image has been transferred is preheated by the preheater 1 in order to promote the fixing property, and the heat roll is rotated at the same peripheral speed as the paper feeding speed. 2 (heating roll)
Then, the paper is fed and the toner is fixed by the backup roll 3 (pressure roll).

The preheater 1 for preheating the entire sheet from the back surface performs suction of air from a suction paper brake 5 and an air suction port 10 on the preheater 1 in order to maintain close contact with the preheater 1.

As described above, in this type of electrophotographic printer, the preheater 1 is provided immediately before the heating / pressing stage in order to promote the fixing property. In the case of the apparatus, the start and stop of the printer operation are frequently repeated, so that the running of the continuous paper for printing is intermittent, and the paper may be stopped on the preheater 1 from the stop state to the restart. .

The preheater 1 is normally kept at a high temperature of about 100 degrees Celsius so as to be able to respond to normal high-speed printing. There is a possibility that wrinkles may occur on the eye sheet or yellowing of the sheet may occur.

To cope with such a problem, Japanese Utility Model Application
No. 9-128663 and Japanese Utility Model Application Laid-Open No. 62-81970.
The technology described in Japanese Unexamined Patent Publication (Kokai) No. H11-27911 is disclosed.

In the technique disclosed in Japanese Utility Model Laid-Open Publication No. 59-1288663, an electromagnetic valve is provided between a suction path of a suction mechanism for bringing a sheet into close contact with a preheater and a suction blower, and the electromagnetic valve is opened during printing. By providing a means for closing the sheet during non-printing, it is intended to prevent yellowing and wrinkling of the sheet.

According to the technique described in Japanese Utility Model Application Laid-Open No. 62-81970, at the same time as the printing operation is stopped, the rotation of the blower that is sucking air is stopped, or the rotation is reversed so that the preheater and the printing paper are not rotated. By lowering the adhesiveness of the printer and returning the printing paper to the printing system by the restoring force of the buffer arm, the preheater upper limit heating temperature can be set higher than before, and the printing line width and brightness of the toner are averaged. At the same time as improving the printing quality as compared with the related art, the size of the preheater is reduced, and the cost of this type of printing machine is reduced.

[0014]

The above-mentioned conventional printer apparatus uses the above two types of paper in the case of using a receptive paper whose heat shrinks sharply compared with general high-quality paper or a paper which absorbs moisture and has a high moisture content. In the related art, when the intermittent printing is stopped, the printing paper is sandwiched and fixed by the pressure roll. Therefore, the pre-fixed printing paper stretched between the buffer arm and the pressure roll from the preheater heated to a high temperature only by the restoring force of the buffer arm or the like. Cannot be completely released, and wrinkles are formed on pages 1 and 2 of the printing paper immediately after the intermittent restart.

An object of the present invention is to eliminate the above disadvantages,
An object of the present invention is to provide a printer device that suppresses thermal shrinkage of printing paper and prevents wrinkles.

[0016]

According to the present invention , there is provided an alarm signal generating means for generating an alarm signal when printing is stopped for a predetermined time or more in a printer using a heater roll fixing system using continuous paper as a medium. And a pressure low in response to the supply of the alarm signal.
Reverse conveying means for rotating the paper in a reverse direction for a predetermined time to return the continuous paper on the pre-heater in a direction opposite to the conveying direction by a predetermined amount;
Air ejecting means for ejecting air to the continuous paper on the preheater in response to the supply of the alarm signal and causing the continuous paper to float from the preheater.

[0017]

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the printer according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a fixing unit of the printer of this embodiment, FIG. 2 is a block diagram of a control unit, and FIG. 3 is a timing chart of print signals and switching of air ejection / suction on a preheater and rotation of a pressure roll. It is.

As shown in FIG. 1, the configuration around the fixing section of the printer of this embodiment is a preheater 1, a heat roll 2, a backup roll 3, and a pressure roll 4, which are components of a conventional printer. , A suction paper brake 5, a hose 6, and an air suction device 7, a pressure roll motor 25 whose rotation direction is controlled by the control unit 11, an air ejection device 8 for ejecting air, Pressure roll motor 2 under certain conditions after printing is stopped and at the start and end of printing
5, a control unit 11 for controlling the air suction device 7 and the air ejection device 8.

The operation at the time of printing is the same as that of the above-mentioned conventional printer, so that the description is omitted.

As described above, the receipt paper and the paper having a high moisture content due to moisture absorption are thermally contracted when stopped on the pre-heater 1 for a certain period of time or longer. In this embodiment, it is assumed that the stop time at which wrinkles occur is 4 seconds.

As shown in FIG. 1, an air blower 8 is installed in parallel with an air suction machine 7, and these are controlled by a control unit 11 so as to perform switching of suction and blow air from the back surface of the preheater 1. Do.

Further, even if air is blown out while the paper is stretched on the preheater 1, the paper on the preheater 1 cannot be completely lifted.
Is temporarily reversed by a predetermined amount in the direction of rotation of the pressure roll 4 that is pulling the paper from the paper to the fixing unit 17, so that the tension on the paper on the preheater 1 is temporarily loosened. 1. The sheet is completely lifted from above (see the overall view of FIG. 4).

The control section 11 will be described with reference to FIG.

The control unit 11 includes a print signal detection circuit 20
, An oscillator 22, a timer circuit 21, an air switching circuit 24, and a pressure roll switching circuit 26.

When a print ON / OFF signal (ON indicates start of printing and OFF indicates stop of printing) is input from the host computer, the print signal detecting circuit 20 responds to the input of a print ON / OFF signal. An ON signal or an OFF signal is generated and supplied to the pressure roll switching circuit 26.

The oscillator 22 generates a clock pulse signal for clock measurement and supplies it to the clock terminal of the timer circuit 21.

The timer circuit 21 starts measuring time after receiving the print stop signal (OFF signal) from the print signal detection circuit 20 and does not receive the next print start signal (ON signal) even if 3 seconds or more have elapsed. It is determined that there is a danger of thermal contraction, and an alarm signal is sent to the air switching circuit 24 and the pressure roll switching circuit 25 to be reset. It is also reset in response to the supply of the print start signal.

The air switching circuit 24 sends a start signal to the air suction device 7 and a stop signal to the air ejection device 8 in response to the supply of a print start signal from the print signal detection circuit 20, and starts the air suction device 7. Then, the air ejector 8 is stopped. In addition, in response to the supply of the print stop signal from the print signal detection circuit 20, a stop signal is sent to the air suction device 7 to stop the air suction device 7. Further, when an alarm signal is supplied from the timer circuit 21, a start signal is sent to the air ejector 8 to send the air ejector 8.
Start.

The pressure roll switching circuit 26 supplies a forward rotation start signal to the pressure roll motor 19 in response to the supply of the print start signal from the print signal detection circuit 20 to move the pressure roll 4 in the forward direction (in the transport direction of the continuous paper 12). ), And the continuous paper 12 is transported by the pressure roll 4 in the transport direction. Further, in response to the supply of the print stop signal from the print signal detection circuit 20, a stop signal is supplied to the pressure roll motor 19 to stop the rotation of the pressure roll 4 and stop the conveyance of the continuous paper. Further, when the alarm signal is supplied from the timer circuit 21, a reverse rotation start signal is supplied to the pressure roll motor 19 for a certain period of time, and the pressure roll 4 is rotated in the reverse direction for a certain period of time. In the direction opposite to the transport direction.

Referring to FIG. 3, the air control and the pressure roll control by the control unit 11 will be described.

When the print signal is turned on, that is, when the print start signal is supplied, the air suction device 7 is activated to start the air suction, and at the same time, the pressure roll 4 rotates forward to start conveying the continuous paper 12 in the conveying direction. When the print signal is turned off, that is, when the print stop signal is supplied, the air suction device 7 stops and the air suction stops, and at the same time, the pressure roll 4 stops and the conveyance of the continuous paper 12 stops.

When the print signal changes from ON to OFF,
The timer circuit 21 starts counting the stop time. When the count time exceeds 3 seconds, it is determined that the heat shrinkage is dangerous, and an alarm signal is supplied to the air switching circuit 24 and the pressure roll switching circuit 26.

In response to the supply of the alarm signal, the air ejector 8 is started, and compressed air is blown from the air suction port 10 of the preheater 1 to the back surface of the sheet via the hose 6.

In synchronism therewith, the pressure roll 4 reversely rotates by a fixed amount to loosen the tension of the paper between the suction paper brake 5 and the pressure roll 4 once, so that the continuous paper 12 is easily raised from above the preheater 1.

On the other hand, when printing is restarted, in response to the supply of the print start signal, the pressure roll 4 rotates forward to transport the continuous paper 12 in the transport direction, and at the same time,
After the air suction device 7 is activated to bring the paper between the suction paper brake 5 and the pressure roll 4 into close contact with the pre-peater 1, the printing operation is restarted. of course,
When the air ejector 8 is operating, it is stopped in response to the supply of the print start signal.

As described above, in the printer according to the present embodiment, when the print stop time is longer than a predetermined time, the continuous paper on the preheater is loosened and the jet air is supplied to the continuous paper to preheat the continuous paper. By completely floating the sheet from above, it is possible to prevent wrinkles generated on the sheet.

[0039]

As described above, the printer device of the present invention counts the intermittent temporary stop time, and after a certain period of time has elapsed after the stop, rotates the pressure roll in a reverse direction by a fixed amount to remove the printing paper on the pre-heater. Once the tension is loosened, air is blown out from the back of the printing paper to completely lift the paper from above the pre-heater, so that wrinkles that easily enter heat-shrinkable receipt paper or paper that has absorbed moisture and has a high moisture content Has the effect of preventing

[Brief description of the drawings]

FIG. 1 is a configuration diagram around a fixing unit of a printer device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control unit.

FIG. 3 is a time chart of a print signal, switching of air ejection / suction on a preheater, and rotation of a pressure roll.

FIG. 4 is an overall configuration diagram of a conventional printer device.

FIG. 5 is a configuration diagram of a main part of a fixing unit of a conventional printer device.

FIG. 6 is a perspective view of a fixing unit of a conventional printer device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 preheater 2 heat roll 3 backup roll 4 pressure roll 5 suction paper brake 6 hose 7 air suction device 8 air ejection device 10 air suction port 11 control unit 12 continuous paper 13 hopper unit 14 electrophotographic unit 15 photoconductor 16 tractor unit 17 fixing Unit 18 Stacker unit 19, 25 Pressure roll motor 20 Print signal detection circuit 21 Timer circuit 22 Oscillator 23 Power supply circuit 24 Air switching circuit 26 Pressure roll switching circuit

Claims (1)

(57) [Claims] An alarm signal generating means for generating an alarm signal when printing is stopped for a certain period of time or more in a printer apparatus using a heater roll fixing method using continuous paper as a medium, and in response to the supply of the alarm signal Pre
Reverse conveyance means for rotating the shallow roll in a reverse direction for a predetermined time to return the continuous paper on the preheater in a direction opposite to the predetermined amount in the conveying direction; and supplying air to the continuous paper on the preheater in response to the supply of the alarm signal. A printer for ejecting the continuous paper from the preheater and ejecting the continuous paper.