JPS5848674Y2 - Non-contact heating mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating fixing device that heats and fixes developer powder images transferred to sheets of paper of various widths, and particularly to a non-contact heating mechanism that can regulate the sheet heating width.

It is used in electrophotographic copying machines that have a fixing device that transfers a developed image formed on a recording surface, for example, a latent image forming drum, onto paper, and heats and fixes the transferred developed image using a heat source such as a halogen lamp. Paper widths generally vary widely.

In this case, the heat source is set to a length that corresponds to the maximum width of paper, so when heating narrow paper, it may heat unnecessary parts other than the paper, causing the temperature near the fuser to rise abnormally. Or heating temperature control becomes difficult.

In particular, in a type of fuser in which an auxiliary heating plate is installed at the bottom of the paper in opposition to the heat source, when heating a small width of paper, the part of the auxiliary heating plate below the paper that is outside the paper is directly heated by the heat source, and the auxiliary heating plate is heated directly by the heat source. There was a problem in that the temperature distribution of the heating plate became non-uniform, which adversely affected the heat fixation of the developed image made of developer powder.

The present invention is intended to solve the above-mentioned problems, and aims to provide a non-contact heating mechanism that can uniformly heat and fix images transferred to paper sheets of various widths.

Embodiments of the invention will now be described with reference to the drawings.

Fig. 1 is a schematic perspective view of the non-contact heating mechanism according to the present invention, and Fig. 2 is a detailed cross-sectional view of Fig. 1. In the figure, 1 is a rotary slitter, 2 is an outer cylinder, 3 is a glass plate, and 4 is a detailed cross-sectional view of the non-contact heating mechanism according to the present invention. An auxiliary heating plate, 5 a halogen lamp, and 6 a lamp cover.

The rotary slitter 1 has a cylindrical shape, and, as shown in detail in FIG. 2, is fixed to a shaft 7 rotatably supported by both side plates 2a of an outer cylinder 2 via bearings (not shown).

This rotary slitter 1 has a plurality of notches 8A, 8B, 8C, . . . with lengths corresponding to various paper widths.
... are continuously formed in a step-like manner in the circumferential direction.

A slit 9 is formed in the outer cylinder 2, and the glass plate 3 is mounted within this slit 9 via a mounting plate 10.

The paper 20 to which developing powder is attached is sent between the glass plate 3 and the auxiliary heating plate 4 in the direction of the arrow in FIG.

The halogen lamp 5 is a glass plate 3 inside the rotary slitter 1.
It is provided at a position opposite to the side plate 2 of the outer cylinder 2, and its both ends are
It is connected to a socket 11 attached to a.

Both the auxiliary heating plate 4 and the halogen lamp 5 have a length corresponding to the maximum width of the paper.

When heating and fixing an image made of developer powder adhering to a sheet 20 that is being fed in the direction of the arrow, the shaft 7 is rotated so that the notch of the rotary slitter 1 corresponding to the width of the sheet 20 is aligned with the glass plate 3 and the halogen lamp 5. Make sure it's in between.

When the paper 20 is heated by the auxiliary heating plate 4 and the halogen lamp 5 in this state, the heating width of the halogen lamp 5 is restricted by the notch of the rotary slitter 1 and it heats only the width of the paper. The portion outside of the heating plate 20 is not directly heated by the halogen lamp 5, and the temperature distribution of the auxiliary heating plate 4 becomes uniform.

Therefore, it is possible to perform stable heat fixing and improve fixing quality.

Note that the air between the rotary slitter 1 and the outer cylinder 2 is sucked in the direction shown by the arrow in FIG.
By cooling the outer cylinder 2, you will not get burned even if the outer cylinder 2 is touched.

A shutter 12 (see FIG. 2) is used to block the radiant heat of the halogen lamp from being applied to the paper when the paper is stopped.

As described above, according to the present invention, by rotating a rotary slitter in which a plurality of notches with lengths corresponding to various paper widths are sequentially formed in the circumferential direction of a cylindrical peripheral wall, the width of the paper can be adjusted. It is possible to perform stable heat fixing by positioning a notch having a length between the heat source and the paper, and regulating the width of heating by the heat source within the width of the paper.

In the above-described embodiment, a rotary structure using a cylindrical rotary slitter was explained as a heat shield, but the present invention is of course not limited to this, and for example, a flat heat shield with a notch may be used. may be arranged between the paper and the heat source and moved in a two-dimensional direction.

In addition, the notch is not physically cut out, but has a structure that allows selection of thermal isolation 9 passage, for example, leaving a part corresponding to the shape of the notch in a cylindrical or flat glass plate, and cutting it into other parts. Various modifications are possible, such as applying a reflective film to the area.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the non-contact heating mechanism according to the present invention, and FIG. 2 is a detailed front sectional view of the same. In the figure, 1 is a rotary slitter, 2 is an outer cylinder, 3 is a glass plate, 4 is an auxiliary heating plate, 5 is a halogen lamp (heat source), 7 is a shirt l-1
8A, 8B, 8C, . . . are notches, 9 is a slit, 10 is a mounting plate, and 20 is paper.

Claims (1)

[Scope of utility model registration request] In a non-contact heating mechanism that includes a heat source that supplies radiant heat to a sheet of paper with developer powder attached to its surface, the radiant heat is supplied from the heat source by moving according to the width of the sheet between the sheet of paper and the heat source. A non-contact heating mechanism that includes a heat shield plate that sets the area to which radiant heat is applied to the width of the paper.