JPS6014278Y2 - electronic photo printer - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an electrophotographic printer.

More specifically, the present invention relates to an electrophotographic printer suitable for printing recorded information on a long continuous recording paper, such as a printer for a computer.

In electrophotographic printers that need to record information at high speeds, such as computer printers, the recording paper is not sheet paper, but long continuous paper such as roll paper or perforated folded paper. Recording paper is commonly used.

In an electrophotographic printer, the recording paper after the information has been transferred from the photosensitive drum is sent to a fixing heater, where the information (toner) is fixed by being heated.

By the way, in the case of long continuous recording paper, unlike the case of sheet-fed paper, the paper is constantly in contact with the fixing heater, so when it comes to stopping the paper conveyance, a link mechanism is used to move the paper. The paper is lifted from the fixing heater and removed from contact to prevent the paper from burning.

However, when lifting this paper, the length of the paper changes, which causes the paper to be pulled against the nip force of the take-up roll, which causes the print surface to be rubbed by the take-up roll, deteriorating print quality. Something happens.

Additionally, fusing heaters are generally sealed systems for thermoeconomic reasons, but if the above-mentioned link mechanism is provided, paper may get caught in the closed system, causing problems such as paper jams. .

Such paper jams can lead to the risk of burning the paper.

The purpose of the present invention is to eliminate the drawbacks of the prior art as described above, and to prevent the paper from burning without having to lift the recording paper from the fixing heater when paper conveyance is stopped.
It is an object of the present invention to provide an electrophotographic printer that does not cause deterioration in print quality.

The present invention, which is distantly related to the above object, transports a long piece of recording paper to a transfer section of a photosensitive drum by a recording paper conveyance means, and fixes recorded information transferred to the recording paper in the transfer section using a fixing heater. In the electrophotographic printer, the fixing heater includes a paper contact plate, a rubber heater built in the back of the paper contact plate, and a pressing plate that presses the rubber heater toward the back of the paper contact plate with elastic force. The fixing heater is turned on in response to the conveyance and stop of the recording paper conveyance means.
, which is characterized by an electrophotographic printer that is turned off.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below with reference to embodiments of the present invention shown in the drawings.

FIG. 1 is a schematic front view of an electrophotographic printer according to an embodiment of the present invention.

1 is a photosensitive drum, and this photosensitive drum 1 rotates in the direction of the arrow.

A charger 2 uniformly charges the photosensitive drum 1.

3 indicates a light pattern of recording information applied to the photosensitive drum 1, whereby the charge on the photosensitive drum 1 disappears in accordance with the light pattern 3 of the recording information, and an electrostatic latent image of the recording information is formed.

A developing device 4 brings toner (developer) into contact with the electrostatic latent image on the photosensitive drum 1 to visualize it.

A transfer charger 5 transfers recorded information visualized on the photosensitive drum 1 onto a long continuous recording paper 6 that is carried into the photosensitive drum 1.

A cleaning brush 7 wipes off toner remaining on the surface of the photosensitive drum 1 after the recorded information is transferred to the recording paper 6.

Reference numeral 8 denotes a recording paper conveying track, which has many pins planted on its surface and constitutes a kind of sprocket wheel.

These pins fit into feed holes formed at both ends of the recording paper 6 in the longitudinal direction, thereby regulating the position of the recording paper 6 in the width direction and conveying it at a constant speed.

Transfer guides 9 and 10 are provided so as to be in contact with the photosensitive drum 1 across the discharger 5, and serve to bring the recording paper 6 into close contact with the photosensitive drum 1.

A fixing heater 11 fixes the toner transferred to the recording paper 6 via the transfer guide 9, discharger 5, and transfer guide 10 that constitute a transfer section.

12 is a take-up roll. The fixing heater 11 has a structure as shown in FIGS. 2 and 3.

In FIGS. 2 and 3, reference numeral 21 denotes a contact plate, which is made of a metal with a small heat capacity, such as aluminum or brass.

A rubber heater 22 is provided on the back of the paper contact plate 21, and the rubber heater 22 is adhered to the paper contact plate 21 with heat transfer cement 23, which is a good thermal conductor.

A curved plate spring 25 is provided on the back of the rubber heater 22 with a heat insulating material 24 in between.

A plurality of leaf springs 25 are fixed to the contact plate 21 at a constant pitch by mounting holes 26 and 27, and their elastic force presses the rubber heater 22 against the back surface of the contact plate 21 to improve adhesion. That's what I do.

The rubber heater 22 is made of a flexible material, and is constructed by embedding a low-drag metal wire such as nichrome wire in a heat-resistant elastic plastic such as silicone rubber. It is characterized by high density.

In order to provide flexibility, the metal low-drag wire preferably has a structure in which the core is glass fiber and is spirally wound around the core.

The fixing heater 11 described above is turned on and off in conjunction with the movement of the recording paper transport track 8 and the take-up roll 12, which are recording paper transport means.

That is, the transport track 8 and the take-up roll 12
While conveying the recording paper 6, the fixing heater 11 is turned on, and when conveyance is stopped, the fixing heater 11 is turned off.This prevents burning of the recording paper 6 while the conveyance is stopped. .

The fixing heater 11 includes a contact plate 21 and a rubber heater 2.
Since No. 2 has a small heat capacity, it exhibits sensitive temperature responsiveness.

That is, as shown in FIG. 4, the paper discoloration limit temperature Tc is set at Sakai, and the fixing heater 11 is at a fixing temperature H that exceeds Tc while the recording paper is being conveyed, but immediately drops below the paper discoloration limit temperature Tc when the conveyance stops. It is designed to drop to a temperature of
This ensures that a predetermined temperature is reached even when the recording paper is frequently fed and stopped.

In the fixing heater 11 described above, both the contact plate 21 and the rubber heater 22 have a small heat capacity, and in addition, the plate spring 25 connects the rubber heater 22 to the contact plate 21 from the inner surface.
Because it is held down with elastic force, H-L at frequent temperatures
Even if there is a difference in thermal expansion of the constituent materials due to changes, no voids are created, and good thermal conductivity is always maintained, allowing for sensitive temperature responsiveness.

As mentioned above, according to the present invention, the fusing heater itself turns ON and OFF in correspondence with the recording paper transport means, and while it is stopped, the temperature drops below the paper discoloration limit temperature, so the paper does not discolor as easily as with conventional link mechanisms. Since the length of the paper does not change, the print quality does not deteriorate due to changes in the length of the paper.

The fixing heater has a structure consisting of a paper contact plate, a rubber heater built into the back of the paper contact plate, and a pressing plate that presses the rubber heater toward the back of the paper contact plate with elastic force. Heater itself ON/OFF
Even if there is a difference in thermal expansion of the constituent materials caused by F, it is possible to exhibit a sensitive temperature response that always maintains good thermal conductivity.

[Brief Description of the Drawings] Figure 1 is a schematic front view of an electrophotographic printer according to an embodiment of the present invention, Figure 2 is a longitudinal sectional front view of a fixing heater used in the present invention, and Figure 3 is a schematic front view of an electrophotographic printer according to an embodiment of the present invention. FIG. 4, which is a side view taken along the line A-A', is a graph showing the temperature responsiveness of the fixing heater. 1...Photosensitive drum, 5...Discharger, 6
...Recording paper, 8...Recording paper transport track, 6,1o...Transfer guide, 11...
・Fusing heater 12... Take-up roll, 21.
・・・・Paper board, 22・・・・Rubber heater,
25...Plate spring.

Claims (1)

[Scope of utility model registration request] In an electrophotographic printer, a long length of recording paper is conveyed to a transfer section of a photosensitive drum by a recording paper conveyance means, and recorded information after being transferred to the recording paper is fixed by a fixing heater & is composed of a paper contact plate, a rubber heater built into the back of the paper contact plate, and a pressing plate that presses the rubber heater toward the back surface of the paper contact plate with elastic force, and the fixing heater is connected to the recording paper conveying means. An electrophotographic printer characterized in that it is turned on and off in response to conveyance and stop of the printer.