JPH11133780A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a feeding quantity of oil from the oil bottle to oil applying means, and to improve a fixing performance of a printing device by providing a recessed section so as to make a part of the oil applying means dipped in the oil pan, and arranging the recessed section in almost proximity to the oil applying means. SOLUTION: This device is allowed to provided the oil pan 150, for storing the oil from the oil bottle, and disposing the recessed section 151 in a part thereof. The device is allowed to reduce the quantity of the oil staying in the recessed section by arranging the gap between the recessed section bottom part 152 and the recessed section side part 153 of the recessed section 151, and the oil feeding felt bottom part 154 and the oil feeding felt bottom section side part 155 proximity. In other wards, a shape of the recessed section 151 decided, based on the width of the oil feeding felt. As a result, by eliminating the need of storing the excess oil, while storing the minimum necessary oil in the recessed section, feeding the same to the oil feeding felt, making the fixing property of the printing device possible to be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device, and more particularly, to a structure for supplying oil to oil applying means.

[0002]

2. Description of the Related Art Conventionally, as a heat fixing device used in a color printer or a color copying machine, there are two rollers having a heater inside and a surface covered with an elastic layer, that is, a heating roller and a pressure roller. A fixing method in which a contact portion is formed and a sheet on which an unfixed toner image is formed is fixed while nipping and conveying the sheet is widely used.

In this fixing system, an oil applying means is provided to supply a fixed amount of oil to the surface of the heating roller. However, in order to supply oil from the oil bottle to the oil applying means, the oil is applied from the oil bottle. Generally, an oil pan for storing oil is provided.

[0004]

However, a large amount of oil is required to stabilize the amount of oil supplied from the oil bottle to the oil applying means in order to improve the fixing performance of the printing apparatus.

[0005]

A feature of the present invention is that a heating roller whose surface is coated with silicone rubber, a pressure roller in contact with the heating roller, and a heating roller and a pressure roller are respectively connected in series inside the heating roller and the pressure roller. Connected heater, oil applying means for applying a fixed amount of oil to the surface of the heating roller,
An unfixed toner image formed on the surface of an oil bottle that supplies oil to the oil application unit, and a cleaning member that is in contact with the surface of each of a heating roller and a pressure roller, and that has a sheet or the like passed between the rollers. In a fixing device for fixing the oil, an oil pan for storing oil from the oil bottle is provided with a concave portion so that a part of the oil applying means is immersed, and the concave portion is made substantially close to the oil applying means. Fixing device.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

The printing apparatus main body 25 includes developing units 1 to 4, an optical unit 5, a charging unit 8, a photosensitive belt 22, a transfer drum 21, a registration roller 12, a transfer roller 13, a static eliminator 15, a fixing unit 19, and a paper discharge. The rollers 18 and the paper feed cassette 6 are main components.

Next, the operation of the printing apparatus main body 25 will be described.

The charger 8 uniformly charges the photosensitive belt 22 in response to a print start signal from a host (not shown).

The optical unit 5 draws a latent image on the photosensitive belt 22 according to print data sent from the host,
The drawn latent image is developed by any one of the developing devices 1 to 4, and the colored particles in the developing device are applied on the photosensitive belt 22.

The photosensitive belt 22 is rotated by a drive source (not shown) to transfer the colored particles on the photosensitive belt 22 onto the transfer drum 21.

Excessive colored particles remaining on the transfer drum 21 are removed by a cleaner a20, and excess colored particles remaining on the photosensitive belt 22 are removed by a cleaner b23. 8 is charged.

In the case of color printing, this process is repeated three or four times while switching the developing device.

A visible image is formed on the transfer drum 21 by colored particles of a single color or a plurality of colors, and when the desired transfer is completed, or in advance, the paper 2 is transferred from the paper feed cassette 6.
7 is pulled out by the paper feed roller 10 and stands by at the registration roller 12.

At a timing when the position of the visible image formed on the transfer drum 21 coincides with the transfer position on the sheet, the sheet waiting at the registration roller 12 starts to be conveyed again, and At 13 the visible image is transferred to the paper side.

The paper is peeled off from the transfer drum 21 by the static eliminator 15, the colored particles are fixed on the paper by the fixing device 19, and are discharged to the paper discharge tray 28.

FIG. 2 is a sectional view of the fixing device 19 according to the present invention, and FIG. 3 is a plan view of the fixing device 19 according to the present invention.

The heating roller 127 and the pressure roller 128 are placed on a pipe-shaped core 127-1, 128-1, respectively, and have a thickness of 1.5 mm and a silicone rubber 127-JIS hardness of 40 degrees.
2. An elastic roller covered with 2,128-2, having a heater 129 of 400 W and a heater 1 of 300 W
30.

The heating roller 127 is provided around the heating roller 127.
Cleaning roller having heat-resistant fibers coated on a metal core for removing offset toner attached to the surface of 27
131, a temperature sensor 132 for detecting the temperature of the surface of the heating roller 127, and an oil application unit 133 for applying silicone oil stably.

The heating roller 1 is provided on the surface of the pressure roller 128.
A fuse 135 is provided to cut off the current when the heaters 129 and 130 are abnormally heated due to a malfunction of the cleaning pad 134 for removing the offset toner transferred from the heater 27 and the temperature sensor 132 or the like.

Both sides are covered with a cover A14 for safety.
6, protected by cover B147.

The oil application unit 133 includes the heating roller 1
27, an oil supply felt 142 for supplying the silicone oil supplied from the oil bottle 141 by capillary action, and an oil blade 143 for regulating the amount of the silicone oil applied to the surface of the heating roller 127 to a certain amount. It is fixed to a heating roller frame 144 holding a heating roller 127, a temperature sensor 132 and the like.

When the heating roller 127 rotates in the direction of the arrow, an oil film of silicone oil is formed on the surface of the heating roller 127, and the releasability between the toner and the surface of the heating roller 127 is improved.

The paper 137 on which the unfixed toner image 136 is formed is conveyed by the entrance guide 138 from the direction of the arrow to the pressure contact portion between the heating roller 127 and the pressure roller 128,
Then, after the toner is fixed on the sheet by the heat and pressure from both rollers, the toner is discharged in the direction of arrow B according to the guides 139 and the discharge guide 140 which also serve as the case of the cleaning roller 131.

Most of the toner fixed at the pressure contact portion between the heating roller 127 and the pressure roller 128 remains on the paper 137, but a small amount of toner (offset toner)
Attach to 27.

The offset toner is removed by the cleaning roller 131. However, it is difficult to completely remove the offset toner by the cleaning roller 131, and the offset toner that cannot be completely removed is removed by the heating roller 127 and the pressure roller 128. It accumulates on the surface and reduces the releasability of the roller surface.

If the oil supply felt 142 is contaminated by the offset toner, the oil supply from the oil supply felt 142 to the heating roller 127 becomes insufficient.
The releasability of the roller surface is reduced.

Here, it is necessary to supply the oil quantitatively from the oil bottle 141 to the oil supply felt 142, but conventionally, as shown in FIG. 5, the oil from the oil bottle 141 is stored. For this purpose, an oil pan 150 is provided, a concave portion B156 is formed in a part of the oil pan 150, and oil is stored in the concave portion of the concave portion B156. It is configured.

In this case, the bottom 15 of the recess B
7, recess B side 158, oil supply felt lower part 15
4. Since the interval between the oil supply felt lower side portions 155 is large, it is necessary to store excess oil in the recess of the recess B156 in order to supply oil to the oil supply felt 142.

In FIG. 4, the gap between the bottom 152 of the recess A 151, the side A of the recess A 153, the lower portion 154 of the oil supply felt, and the lower side 155 of the oil supply felt is close to the oil stored in the recess A. Was reduced.

In other words, the person who has determined the shape of the concave portion A151 to the width of the oil supply felt.

Thus, there is no need to store excess oil in the concave portion, and the oil can be supplied to the oil supply felt while storing the minimum necessary oil in the concave portion.

[0033]

According to the present invention, the supply amount of oil to the oil supply felt can be maintained with a constant and minimum amount of accumulated oil, so that the fixing performance of the printing apparatus can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a fixing device showing one embodiment of the present invention.

FIG. 3 is a plan view of a fixing device showing one embodiment of the present invention.

FIG. 4 is a sectional view of a main part of an oil pan showing one embodiment of the present invention.

FIG. 5 is a sectional view of a main part of an oil pan showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Developing device 1, 2 ... Developing device 2, 3 ... Developing device 3, 4 ... Developing device 4, 5 ... Optical unit, 6 ... Paper cassette 1, 8 ... Charging device, 10 ... Paper roller 1, 12 ... Registration roller, 1
3: transfer roller, 15: static eliminator, 18: discharge roller, 1
9: fixing device, 20: cleaner a, 21: transfer drum, 2
2: photosensitive belt, 23: cleaner b, 25: printing device main body, 27: paper, 28: discharge tray, 127: heating roller, 127-1, 128-1: cored bar, 127-2, 12
8-2: Silicon rubber, 128: Pressure roller, 129, 1
30 ... heater, 131 ... cleaning roller, 132 ...
Temperature sensor, 133: oil application unit, 134: cleaning pad, 135: fuse, 136: unfixed toner image, 138: entrance guide, 139: guide,
140: paper ejection guide, 141: oil bottle, 142 ...
Oil supply felt, 143 ... oil blade, 144
... Heating roller frame, 145 ... Pressing roller frame,
146 cover A, 147 cover B, 148 fixed lever, 150 oil pan, 151 recess A, 152
Recess A bottom, 153 Recess A side, 154 Oil supply felt lower part, 155 Oil supply felt lower side,
156: recess B, 157: bottom of recess B, 158: recess B
side.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsuyoshi Onose 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Inside the Taga Headquarters, Hitachi, Ltd.Electrical Equipment Division (72) Inventor Riki Hiraoka, Tsuchiura City, Ibaraki Prefecture 502, Machi, Machinery Research Laboratory, Hitachi, Ltd.

Claims (2)

[Claims] A heating roller having a surface coated with silicone rubber; a pressure roller in contact with the heating roller; a heater connected in series to each of the heating roller and the pressure roller; An oil application unit for applying a predetermined amount of oil, an oil bottle for supplying the oil to the oil application unit, and a cleaning member in contact with the surface of each of a heating roller and a pressure roller are provided. In a fixing device for fixing an unfixed toner image formed on the surface thereof, a concave portion is provided so that a part of the oil application unit is immersed in an oil pan for storing oil from the oil bottle,
A fixing device, wherein a wall of the concave portion is substantially brought close to the oil applying means. 2. A fixing device according to claim 1, wherein a bottom of said concave portion is made substantially close to said oil applying means.