JPH0115068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flash lamp fixing device, which is installed in a facsimile machine, a copying machine, a printer, etc., and which fixes a toner image formed on the surface of a recording medium by light emission from a flash lamp.

Figures 1 and 2 show conventional devices of this type. Reference numeral 1 denotes a recording medium on which a toner image is fixed, and is conveyed in the direction of arrow P. A reflecting mirror case 2 is provided above the conveyance path of the recording medium 1 .
The reflecting mirror case 2 is provided with an opening 3 at its lower portion facing the conveyance path of the recording medium 1, and a reflecting surface 2a is formed on the inner surface.

A flash lamp 4 is housed in the reflector case 2 so as to be perpendicular to the transport path of the recording medium 1 in the direction of its tube axis. It faces the transport path of the body 1. Further, the entire surface of the opening 3 is covered with a light-transmitting cover 5 made of heat-resistant glass.

Then, the flash lamp 4 is lit intermittently, and the direct light from the lamp 4 and the light emitted from the lamp 4 and reflected by the reflective surface 2a pass through the transparent cover 5 and follow the conveyance path. By irradiating the surface of the recording medium 1 being conveyed, the toner image on the surface of the recording medium 1 is fixed. In addition, the first
In the figure, FW indicates the required maximum fixing width (maximum width of the area where the fixing action can be performed) in the direction orthogonal to the conveying direction of the recording medium 1.

The reason why the opening 3 is covered by the transparent cover 5 is that without the cover 5, evaporated particles generated from the toner image heated by the flash lamp 4 would be exposed to the flash lamp 4 and the light-transmitting cover 5. This is because the particles adhere to the reflective surface 2a and reduce the energy incident on the recording medium 1, and if this is left untreated, it will eventually lead to poor fixing. (In addition,
Even when a transparent cover 5 is provided, the evaporated particles adhere to the cover 5, so it is necessary to clean the cover 5 at an appropriate time. It's much easier than doing that. ) However, in such conventional devices, due to the structure of the device, the distribution of incident energy on the fixing surface (the surface of the recording medium 1) is not uniform, and is high in the central portion and near both ends of the maximum fixing width. It was getting low. FIGS. 3a and 3b representatively show the distribution state of such incident energy by the distribution of the incident energy on straight lines A-A and B-B that are perpendicular to the conveying direction of the recording medium 1. It is something that
Here, the A-A line is located at the center in the conveyance direction of the recording medium 1, and the B-B line is located near both ends in the same direction, but the incident energy is applied to the maximum fixing width on either line. Near both ends of the FW, it is significantly lower than in the center. This means that if the incident energy near both ends of the maximum fixing width FW is increased to the required level, the incident energy at the central portion becomes excessive. There was a drawback that the power consumption of the lamp 4 was greater than necessary.

In addition, since the incident energy of the fixing surface in the central portion was excessive, a large amount of the evaporated particles concentratedly adhered to the central portion of the light-transmitting cover 5, resulting in energy loss. Since this caused a loss, it was necessary to set the input power to the flash lamp 4 to be large in anticipation of this loss.This also increased the power consumption of the flash lamp 4 and caused a The disadvantage was that it required frequent cleaning.

The present invention was made in order to eliminate the above-mentioned conventional drawbacks, and can significantly reduce the power consumption of the flash lamp, and also reduce the adhesion of evaporated particles to the transparent cover that covers the opening of the reflector case. death,
It is an object of the present invention to provide a flash fixing device that can eliminate the need for cleaning the transparent cover for a long period of time.

The present invention will be further described below based on embodiments shown in the drawings.

FIGS. 4 and 5 show an embodiment of the present invention, in which parts that are the same as or equivalent to those of the conventional device are designated by the same reference numerals. In this device, opening 3
Of these, only the portion that is more than a certain distance inside the required maximum fixing width FW is covered by the transparent cover 5.
The other configurations are the same as the conventional device.

In this device, as described above, only the portion of the opening 3 that is more than a certain distance inside the maximum fixing width FW is covered by the transparent cover 5.
Near both ends of the FW, there is no energy loss caused by the light from the flash lamp 4 passing through the transparent cover 5, so the distribution of incident energy on the fixing surface in the direction perpendicular to the conveying direction of the recording medium 1 is reduced. is as shown in Figure 6 a and b, and A
-The decrease in the incident energy near both ends of the maximum fixing width FW is extremely small both on the A line and on the B-B line.

Therefore, in this device, the flash lamp 4
Even if we reduce the input power to (which means moving the incident energy distribution curve in FIG.
Since the FW can be secured, the power consumption of the flash lamp 4 can be reduced.

In addition, since the incident energy at the central portion of the fixing surface can be reduced in this way, the adhesion of the evaporated particles to the transparent cover 5 is significantly reduced, so that the There is no need to set the input power to the flash lamp 4 too high in anticipation of energy loss due to adhesion of evaporated particles, and this also makes it possible to reduce the power consumption of the flash lamp 4 (and (This also leads to a reduction in the amount of the evaporated particles adhering to the light-transmitting cover 5).

In addition, (i) the incident energy on the center side of the fixing surface can be reduced as described above, so the amount of evaporated debris generated as a whole can be significantly reduced; (ii) the maximum fixing width of the fixing surface In the parts near both ends of the FW, the incident energy is still lower than in the center part, although there is a difference in degree from the conventional device.
Near both ends of the maximum fixing width FW, the amount of evaporated debris is smaller than in the center. (iii) Near both ends of the maximum fixing width FW, there is air to cool the flash lamp 4, so Since there is a high probability that the evaporated debris in the vicinity will be blown to the outside of the reflector case 2 by the air blast, if the width of covering the opening 3 with the transparent cover 5 is set appropriately, the opening 3 It is possible to reduce the amount of the evaporated particles that enter the reflective mirror case 2 through the portion not covered by the transparent glass 5 and adhere to the flash lamp 4 and the reflective surface 2a to an almost negligible level. .

Note that the larger the width of covering the opening 3 with the translucent cover 5, the smaller the amount of the evaporated debris entering the reflector case 2. As the width approaches the maximum fixing width FW, the decrease in the incident energy near both ends of the maximum fixing width FW increases, so the width needs to be set taking these into consideration.

As described above, in the flash fixing device according to the present invention, only the part of the opening of the reflecting mirror case that is more than a certain distance inside the required fixing width in the direction perpendicular to the conveyance direction of the recording medium is covered with a transparent cover. As a result, the power consumption of the flash lamp can be significantly reduced, and the adhesion of evaporated particles from the toner image to the cover can be reduced, making it unnecessary to clean the cover for a long period of time. can get.

[Brief explanation of drawings]

Figure 1 is a front view of a conventional flash fixing device.
FIG. 2 is a cross-sectional view of the same, FIGS. 3a and 3b are characteristic diagrams showing the distribution of incident energy on the fixing surface in the conventional device, and FIG. 4 is a front view of a flash fixing device according to an embodiment of the present invention. , FIG. 5 is a cross-sectional view of the same, and FIGS. 6a and 6b are characteristic diagrams showing the distribution of incident energy on the fixing surface in the above embodiment. 1...recording body, 2...reflector case, 2a...
Reflective surface, 3...Aperture, 4...Flash lamp, 5...Translucent glass, FW...Maximum fixing width.

Claims (1)

[Claims] 1. A reflecting mirror case having an opening facing the conveyance path of the recording medium and having a reflective surface on its inner surface, a flash lamp housed inside the reflecting mirror case, and a translucent case that covers the opening. In the flash fixing device provided with a cover, only a portion of the opening portion that is more than a certain amount inside a required maximum fixing width in a direction perpendicular to the conveying direction of the recording medium is covered with the transparent cover. Characteristic flash fixing device.