JPH0420187B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser fixing device such as an electrophotographic copying machine that performs fixing using laser light.

In an electrophotographic copying machine that develops an electrostatic latent image formed on a photoconductive semiconductor film with toner, transfers it to plain paper, and fixes it, the unfixed toner image on the copy paper is fixed using laser light. It is already well known that this is possible, but in reality, it requires a laser with extremely high power, resulting in a problem of enormous power consumption.

The present invention has been made in view of the above-mentioned problems when fixing an unfixed toner image using a laser beam.
In the fixing section of the machine, a mirror-finished flat plate is disposed close to the paper transport path and substantially parallel to the paper transport path, and the laser beam irradiated onto the copy paper is repeated between the copy paper surface and the mirror surface. It is an object of the present invention to provide a laser fixing device for use in a copying machine, etc., which performs back reflection.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

FIG. 1 is a block diagram showing the concept of a general laser fixing device to which the present invention is applied.

That is, after the toner image formed on the photosensitive drum 1 is transferred to the copy paper 3 via the transfer corotron 2, the laser beam emitted from the laser light source 4 is transmitted to the rotating polygon mirror 6 which is rotated at high speed by the motor 5. The reflected light is reflected by the light beam and scanned by the width to be fixed, and the reflected light is focused onto the irradiation line 8 on the surface of the copy paper 3 via a suitable optical path correction lens 7.

However, when simply adopting the above configuration, the area ratio between the white background on the surface of the copy paper 3 and the toner adhesion area is generally already 8:2.
As mentioned above, most of the laser light is scattered in the background, and the energy utilization efficiency of the laser light is extremely low.

In order to solve this problem, in the present invention, the second
As shown in the figure, a flat plate 8 having a mirror surface on one side is disposed substantially parallel to the conveying path of the copy paper 3 having an unfixed toner image attached thereto, and is arranged close to the copy paper 3, and the front edge of the plate 8 and the copy paper The configuration is such that a laser beam 10 is irradiated through a gap 9 between the two.

By doing so, the laser light that has been repeatedly reflected between the mirror surface of the flat plate 8 and the copy paper 3 directly irradiates the paper 3 and the unfixed toner adhering to its surface with the laser light 10. This preheats the film before receiving it to ensure perfect fixing and improves the energy utilization efficiency of the laser light.

It should be noted that the present invention is not limited to the configuration shown in the above-mentioned embodiments; for example, as shown in FIG. A laser beam 10 may also be incident. By doing so, almost all of the laser light diffusely reflected on the surface of the copy paper can be used for heating, which will be more effective.

Further, a plate 13 made of aluminum or the like with a blackened surface is arranged on the back side of the paper conveyance belt 12 on the paper conveyance path directly below the flat plate 8, and the plate 13 is directly heated by a radar beam before and after the copy paper passes through. This makes a large contribution to the preheating of the copy paper, making it possible not only to achieve more reliable fixing, but also to reduce the power of the laser.

Since the present invention is configured as described above, it is possible to significantly improve the energy utilization efficiency of the laser beam used for fixing, so that fixing can be completely performed using a low-output laser, thereby reducing power consumption. It has a significant effect on significant reduction.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the concept of a laser fixing device to which the present invention is applied, FIG. 2 is a side view showing one embodiment of the laser fixing device of the present invention, and FIG. 3 is a side view showing another embodiment. It is a diagram. 3... Copy paper, 8... Mirror flat plate, 10... Laser light, 11... Slit.

Claims (1)

[Claims] 1. In a fixing device such as an electrophotographic copying machine that fixes an unfixed toner image transferred to the surface of a copy paper by irradiating and heating it with a laser beam, a mirror-surfaced flat plate is installed substantially parallel to the conveyance path of the copy paper in a fixing device such as an electrophotographic copying machine. is provided, and by irradiating a laser beam onto the surface of the copy paper through a gap between the edge of the flat plate and the copy paper or through a slit formed in the flat plate, a laser beam is created between the mirror surface and the copy paper. 1. A laser fixing device for use in copying machines, etc., characterized in that light is reflected repeatedly to improve the utilization efficiency of laser light energy.