JPH02130175A - Printing apparatus - Google Patents

Abstract

PURPOSE:To enhance the running stability of both of thick and thin papers by adding necessary tension to paper corresponding to the difference in the thickness of paper. CONSTITUTION:When thin continuous form paper is used, a change-over switch 5 is set to an OFF-state to perform conventional control. When the change-over switch 5 is set to an ON-state in a case using thick paper, an objective value (second objective value) different from that in the case using the thin paper, that is, an objective value capable of applying tension larger than that in the casing using the thin paper is set as the control objective value of the buffer arm 43 of a buffer arm control system 1. In this case, a signal passes through a signal gain increase means 6 and the gain of the angle signal detected by an angle sensor 2 is increased to be sent to a driving control part 3. In this driving control part 3, a signal for controlling the motor speed corresponding to the angle signal increased in its gain is sent to a motor driving means 4. As a result, the speed of a motor 46 is controlled to become the second objective value.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printing device, and particularly to a printing device that uses continuous paper (such as fan-hold paper having folding perforations at predetermined intervals) as a printing medium. Regarding.

[Conventional technology]

FIG. 2 shows a typical configuration example of this type of printing device.

The printing apparatus shown in FIG. 2 includes a laser 10 as a light source,
It includes an optical system 20, a printer section 30, and a paper feeding mechanism 40.

Among these, a helium neon laser is often used as the laser 10, but an argon ion laser is used when high power is required for high-speed recording, and an argon ion laser is used when short wavelength light is needed to improve resolution. It uses blue light from a helium-cadmium laser. Recently, although there are some problems, semiconductor lasers have come into widespread use for the purpose of downsizing devices.

The optical system 20 includes an optical modulator 21, a reflecting mirror 22, and a rotating polygon f.
i23. The optical modulator 21 is for intensity modulating the laser beam from the laser 10,
Acousto-optic light modulators are often used.

Of course, in the case of a semiconductor laser, an optical modulator is not required because it can be directly modulated by current.

The rotating polygon mirror 23 is a type of optical deflector and can scan a laser beam at a very high speed.

In this case, the laser beam whose intensity is modulated by the optical modulator 21 is main-scanned by the rotating polygon mirror 23 via the reflecting mirror 22, and forms a straight line on the photosensitive drum, which will be described later.

The printer section 30 includes a photosensitive drum 31, a charge corotron 32, a developing device 33, and a fixing device 34. The photosensitive drum 31 rotates clockwise in FIG. 2 and performs sub-scanning of the laser beam that is main-scanned by the rotating polygon mirror 23 to form an image.

Selenium (Se) is often used as a photoreceptor, but it only exhibits a photoconductive phenomenon in response to blue light. As mentioned above, exposure with commonly used helium-neon lasers requires materials that are also sensitive to red light, such as selenium, which is sensitive to red light, and organic materials such as polyvinyl carbazole. A photoconductor with red sensitivity is used.

The charge corotron 32 is used to charge the photoreceptor so that charged particles (+) generated by positive corona discharge are uniformly distributed on the surface of the photoreceptor.

At this time, a potential of several hundred (V) is generated on the surface of the photoreceptor.

When the image is exposed to light (modulated light scans the surface of the photosensitive drum 31, which is charged by the above-mentioned scanning system), the charges where the light hits move, and the distribution of the remaining charges forms a latent image. do.

The developing device 33 generates black toner particles (+) that are triboelectrically charged.
) is attached to the exposed areas of the photosensitive drum 31 where there is no electric charge, and the light irradiation pattern is formed as a toner pattern on the surface of the photosensitive drum 31.

The fixing device 34 has a paper path (not shown) formed in the center thereof, and has a heater 35 and a flanche 36 that heat and melt the toner transferred to the paper 100 by a transfer charger 42 (described later), and transfers the toner particles to the paper 100. It is meant to be established.

The paper feed mechanism 40 includes a tractor unit 41, a buffer arm 43 rotatably installed in the vertical direction at the entrance of the fixing device 34, and a paper ejection roller 4 as a feed roller.
4,45.

The tractor unit 41 is installed on the left side of the photosensitive drum 31 in FIG. 2, and sends out the paper 100 in the direction of arrow A in the figure. This will be explained in further detail. The tractor unit 41 includes a transfer charger 42 that is placed at a position facing the photosensitive drum 31 and that transfers toner attached to the photosensitive drum 31 onto the paper 100 by electrostatic attraction. Furthermore, one set of pulleys (not shown) are each provided at the upper and lower ends of the tractor section 41 in FIG.

Each pulley is equipped with a plurality of tractor pins, and the tractor pins are engaged with fan hold holes formed at both ends of the paper 100 to feed the paper 100 in the direction A in FIG. 2.

The buffer arm 43 is always biased counterclockwise in FIG. It can be switched to two levels of strength depending on the paper speed. That is, when the speed is high, the lever 47 is set to strong to apply a relatively strong tension to the paper, and when the speed is low, the lever 47 is set to high.
to reduce the tension applied to the paper.

The paper ejection rollers 44 and 45 are installed on the exit side of the fixing unit 34 through the aforementioned paper path (not shown), facing each other and almost in contact with each other, as shown in FIG. The roller 45 is integrally mounted on the motor shaft of a motor 46, which will be described later, and is driven to rotate.

This rotation of the paper ejection roller 45 causes the paper 100 to be sandwiched between the paper ejection roller 45 and the other paper ejection roller 44, and ejects the paper 100 to a stacker portion 60, which will be described later.

In FIG. 2, the hopper part 50 is used to store paper 100 before printing.
The paper 100 is placed on the paper holder 51 in a folded state. Further, the stacker part 60 is a place for storing the paper 100 after printing is completed, and the paper 100 ejected to the above-mentioned paper ejection rollers 45 and 46 is stored folded from the perforation.

Next, the overall operation of the printing apparatus will be explained.

The continuous paper 100 is transferred from the hopper part 50 to the tractor part 4
Head to 1. When the continuous paper 100 passes through the tractor unit 41, the laser beam generated by the laser 10 is modulated by the optical modulator 21.

A scanned laser beam is applied to the rotating polygon mirror 23 via the reflecting mirror 22, and the charge corotron 32 irradiates the charged photosensitive drum 31 with a scanned laser beam. is placed on the photosensitive drum 31. This toner is placed on the continuous paper 100 and conveyed to the fixing device 34 by the transfer charger 42 .

The toner remaining on the photosensitive drum 31 is removed from the discharge corotron 37. Cleaning 38. The toner is removed by the cleaning fleece 39, and the toner is placed on the paper by repeating the above steps. Further, the continuous paper 100 and the toner carried into the fixing device 34 are fixed by the heater 35 or the flash 36, and then sent to the stacker part 60, where the paper 100 is folded.

In the above-described case, when the paper 100 is carried into the fixing device 34, the running performance of the paper is stabilized by controlling the buffer arm 43.

Next, the control principle of this buffer arm 43 will be explained based on FIG. 3.

The buffer arm control system 70 shown in FIG. 3 uses an angle sensor 2 such as a potentiometer installed on the pivot shaft of the buffer arm 43, and a motor according to the rotation angle signal of the buffer arm 43 detected by the angle sensor 2. It includes a drive adjustment section 3 that outputs a speed adjustment signal, and a motor drive means 4 that drives a motor 46 in accordance with the adjustment signal from the drive adjustment section.

In this case, the rotation angle of the buffer arm 43 from the reference point is detected by the angle sensor 2, and the drive adjustment unit 3 performs predetermined calculation processing based on the detection result to adjust the motor speed adjustment signal to the motor drive. The paper ejection roller 45, which is integrally equipped with the motor 46, is driven by the motor drive means to rotate at a rotational speed corresponding to this adjustment signal. At this time, when the rotation speed of the motor changes, the tension on the paper and the rotation angle of the buffer arm change accordingly. Therefore, changes in the rotation angle of the buffer arm are detected,
By adjusting the rotational speed of the motor so that this rotation angle becomes a predetermined target value, the rotational speed of the motor is kept approximately constant, thereby constantly applying approximately constant tension to the paper and ensuring stable paper running. This is what we are trying to secure.

[Problem to be solved by the invention]

In the conventional example described above, the buffer arm force can be switched in two stages, strong and weak, depending on the paper background, but the rotation angle of the buffer arm is controlled at one point by the buffer arm control system (target This means that if the control system is set for normal continuous paper (thin paper), when special continuous paper (thick paper or wide paper) is used, the problem may occur due to insufficient tension. Poor fixation.

There was an inconvenience that problems such as paper wrinkles occurred.

On the other hand, if the buffer arm control system is set for special paper such as thick paper or wide paper, a sufficient tension is applied to the paper between the tractor section and the fixing section due to the strong buffer arm force. Therefore, stable running performance can be ensured, but when thin paper is used, problems such as the paper tearing at the perforations occur due to the strong buffer arm force.

[Objective of the Invention] The present invention improves the disadvantages of the conventional example, and particularly improves the stability of paper running for both thin and thick paper by adding tension to the paper that is required depending on the difference in paper thickness. The purpose is to provide a printing device that can achieve the following.

[Failure to solve the problem]

In the present invention, a paper path is formed in the center and a fixing section is configured to fix the toner transferred to the running paper, and a fixing section is installed opposite to each other across the paper path at the exit side of the paper path to sandwich the paper. a pair of feed rollers that urge the feed rollers to travel; a motor that drives at least one of the feed rollers; and a buffer arm biased by spring means to apply tension to the paper. The buffer is equipped with an angle sensor that detects the rotation angle of the buffer arm, a drive adjustment section that sends out a motor speed adjustment signal based on the detection result, and a drive means that drives the motor at a rotation speed that corresponds to the adjustment signal. It constitutes a buffer arm control system that detects positional deviation of the arm and controls the rotational speed of the motor.

Furthermore, a first signal transmission circuit is provided that directly connects the angle sensor and the drive adjustment section, and a signal gain variable means that changes the gain of the angle signal detected by the angle sensor and sends it to the drive adjustment section is provided. At least one second signal transmission circuit is provided, and a signal switching means is provided for selectively connecting each of these signal transmission circuits to the angle sensor. This aims to achieve the above-mentioned purpose.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

Here, the same reference numerals are used for the same constituent members as in the conventional example described above.

The embodiment shown in FIG. 1 is characterized in that a changeover switch 5 and signal gain increasing means 6 as signal gain variable means are newly provided in the conventional example shown in FIG. 3 described above.

To explain this in more detail, between the angle sensor 2 and the drive adjustment section 3, there is a first signal transmission circuit 8 that directly connects the two, and a second signal transmission circuit that connects the two via a signal gain variable means. A signal transmission circuit 7 is provided. These signal transmission circuits are selectively connected to the angle sensor 2 by a changeover switch serving as a signal switching means.

The signal gain increasing means 6 has a function of increasing the gain of the rotation angle signal detected by the angle sensor 2 and sending it to the drive adjustment section 3 when the changeover switch 5 is in the ON state.

The other configurations are the same as the conventional example described above.

Next, the overall operation of the above embodiment will be explained.

When using thin continuous paper, set the selector switch 5 to O.
It is only necessary to set it to the FF state, and in this case, conventional control is performed. On the other hand, when using thick continuous paper, the changeover switch 5 is set to the ON state. As a result, the control target value of the buffer arm 43 of the buffer arm control system 1 in this embodiment is a different target value (second target value) from the case of using the thin paper described above, specifically, the control target value is different from the case of using the thin paper described above. A target value that allows a large tension to be applied to the paper is set.

In this case, the signal passes through the signal gain increasing means 6, the gain of the angle signal detected by the angle sensor is increased, and the drive adjustment section 3 increases the gain of the angle signal detected by the angle sensor.
sent to.

The drive adjustment section 3 sends a motor speed adjustment signal corresponding to the angle signal with increased gain to the motor drive means 4. As a result, the speed of the motor 46 is controlled by the motor drive means 4 so that the buffer arm 43 reaches the second target value. As a result, a stronger tension is applied to the paper than when using thin paper.

In this way, when using thick paper, the rotational speed of the motor is controlled at a target value that can apply a larger tension to the paper than when using thin paper, and a stronger, almost constant tension is applied to the paper. is added to ensure stable paper running.

As explained above, according to this embodiment, the buffer arm control becomes two-point control, which makes it possible to stabilize the running of special continuous paper such as thick paper and wide paper, and eliminate the above-mentioned obstacles. It has the advantage that paper can also be used without any problems.

In the above embodiment, the case where the buffer arm control system 1 controls the buffer arm at two points (two target values) was illustrated, but the present invention is not limited to this, and
Point control, four-point control, etc. may be used.

〔Effect of the invention〕

Since the present invention is configured and functions as described above, it is possible to perform buffer arm control at two or more points by the action of the signal switching means and the signal gain variable means provided on the output side thereof. .

For this reason, for example, by setting buffer arm control target values in advance for thick paper and thin paper as in the above embodiment, and performing buffer arm control at two or more points,
The rotational speed of the motor is controlled according to each target value. For this reason, cardboard.

Approximately constant tension of the size required for each thin paper,
It can be added to each.

Therefore, it is possible to provide an unprecedented printing device that is suitable for use with ordinary continuous paper and can prevent problems such as poor fixing and wrinkles on special paper (such as thick paper).

[Brief explanation of the drawing]

FIG. 1 is a conceptual block diagram showing one embodiment of a buffer arm control system which is the main part of the present invention, and FIGS. 2 and 3 are explanatory diagrams showing a conventional example. 1...Buffer arm control system, 2...
Angle sensor, 3... Drive adjustment section, 4...
・Motor driving means, 5... Changeover switch as signal switching means, 6... Signal gain increasing means as signal gain variable means, 7... First signal transmission Circuit, 8... Second signal transmission circuit, 34...
... Fixing section, 43 ... Buffer arm, 44
．． 45... Paper discharge roller as a feed roller, 46... Motor, 100... Paper.

Claims (1)

[Claims] (1) A fixing unit, which has a paper path formed in the center and fixes the toner transferred to the running paper; and a fixing unit, which is installed facing each other across the paper path on the exit side of the paper path, and which fixes the toner transferred to the running paper. A pair of feed rollers that pinch and urge the feed rollers, a motor that drives at least one of the feed rollers, and a motor that is rotatable in directions toward and away from the paper surface of the paper inlet of the fixing section. a buffer arm which is mounted on the paper and is biased by a spring means to apply tension to the paper; an angle sensor that detects the rotation angle of the buffer arm; and a signal for adjusting the motor speed based on the detection result. configuring a buffer arm control system that detects a positional deviation of the buffer arm and controls the rotational speed of the motor using a drive adjustment section and a driving means that drives the motor at a rotational speed according to the adjustment signal, A first signal transmission circuit that directly connects the angle sensor and the drive adjustment section is provided, and a signal gain variable means that changes the gain of the angle signal detected by the angle sensor and sends it to the drive adjustment section. 1. A printing apparatus comprising: at least one second signal transmission circuit connected to the angle sensor; and signal switching means for selectively connecting each of these signal transmission circuits to the angle sensor.