JP-7855915-B2 - Fixing apparatus and image forming apparatus

Inventors

• 池田 英明

Assignees

• コニカミノルタ株式会社

Dates

Publication Date

20260511

Application Date

20220511

Claims (7)

1. An endless fixing belt, A heating roller having a heating source for heating the fixing belt, A fixing member positioned on the inner circumference side of the fixing belt, A pressure roller presses the fixing belt toward the fixing member, and together with the fixing belt, forms a fixing nip section on which the recording medium is transported. A cover is provided on the opposite side from the heating roller, as viewed from the heating roller, and is provided so as to cover the heating roller. A temperature sensor is provided in the cover for measuring the temperature of the fixing belt, Equipped with, The aforementioned cover is Near where the temperature sensor is provided, there is a protrusion that extends toward the fixing belt, An opening is provided where the aforementioned protrusion is exposed and is located away from the fixing belt when viewed from the aforementioned protrusion, Includes, The aforementioned cover is The main body cover on which the temperature sensor is attached, The temperature sensor has a protective cover, The main body cover is provided with a main opening, The protective cover is provided with the protrusion and the opening , By attaching the protective cover from the side of the main body cover opposite to the fixing belt, the protrusion protrudes from the main opening of the main body cover toward the fixing belt. Fixing device.
2. The aforementioned protrusion is, The device is designed such that when it intersects with the aforementioned fixing belt, the angle it makes with the fixing belt is obtuse. The fixing device according to claim 1.
3. The air inflow resistance at the opening is smaller than the air inflow resistance at the gap between the protrusion and the fixing belt. The fixing device according to claim 1.
4. After the mounting position for the temperature sensor on the main body cover has been adjusted, the protective cover is attached to the main body cover. The fixing device according to claim 1 .
5. The aforementioned protrusion is plate-shaped or sheet-shaped. The fixing device according to claim 1.
6. When viewed from the aforementioned temperature sensor, The protrusion and the opening are provided on the upstream side in the rotational direction of the heating roller. The fixing device according to claim 1.
7. An image forming apparatus comprising a fixing device according to any one of claims 1 to 6 .

Description

This invention relates to a fixing device and image forming apparatus using an electrophotographic method in photocopiers, laser beam printers, fax machines, and other multifunction devices. In fixing devices that use non-contact temperature sensors for fixing temperature control, it has been found that false temperature readings can occur due to the influence of airflow near the non-contact temperature sensor. Japanese Patent Publication No. 2021-124652 (Patent Document 1) describes a method of suppressing airflow to the non-contact temperature sensor by providing ribs or seals near the sensor. Japanese Patent Publication No. 2021-124652 This figure shows an example of an image forming apparatus according to Embodiment 1.This is an enlarged longitudinal cross-sectional view of the fixing device of Embodiment 1.This is a schematic diagram showing the airflow from the fan to the fixing device in the image forming apparatus of Embodiment 1.This is a perspective view of the cover as seen from the fixing belt side in Embodiment 1.This is a perspective view of the cover as seen from the opposite side of the fixing belt in Embodiment 1.This is a perspective view of the main body cover as seen from the opposite side of the fixing belt in Embodiment 1.This is a perspective view of only the protective cover as seen from the fixing belt side in Embodiment 1.This is a perspective view of only the protective cover, as seen from the opposite side of the fixing belt in Embodiment 1.This is an enlarged longitudinal cross-sectional view of the fixing device of Embodiment 2.This is a perspective view of the cover as seen from the fixing belt side in Embodiment 2.This is a perspective view of only the protective cover as seen from the fixing belt side in Embodiment 2. The image forming apparatus of each embodiment will be described below with reference to the figures. In the embodiments described below, when referring to the number, quantity, etc., the scope of the present invention is not necessarily limited to that number, quantity, etc., unless otherwise specified. The same reference numeral will be used for the same parts or equivalent parts, and redundant descriptions may not be repeated. <Embodiment 1: Overview of Image Forming Apparatus 1> Figure 1 shows an example of an image forming apparatus 1. Referring to Figure 1, an overview of the hardware configuration of the image forming apparatus 1 will be described. The image forming apparatus 1 comprises a print engine 100, a reading unit 200, and an operation panel 300. The print engine 100 comprises an imaging unit 110, an intermediate transfer belt 120, a fixing device 500, a paper feeding unit 140, a delivery roller 150, a transport roller 160, a registration roller 170, a control unit 180, and a power supply unit 190. The print engine 100 performs printing on the recording medium (paper, sheet-like material, etc.) in the paper feeding unit 140. The delivery roller 150 transports the recording medium from the paper feeding unit 140. Furthermore, the transport roller 160 transports the recording medium in the direction of the intermediate transfer belt 120. The imaging unit 110 includes imaging units 10C, 10M, 10Y, and 10K that form toner images for cyan (C), magenta (M), yellow (Y), and key plate (K), respectively. Each imaging unit 10C, 10M, 10Y, and 10K includes a charging unit (not shown), a developing unit (not shown), a cleaning unit (not shown), and an intermediate transfer contact roller (not shown). The imaging unit 10C includes a photoreceptor 11C. The imaging unit 10M includes a photoreceptor 11M. The imaging unit 10Y includes a photoreceptor 11Y. The imaging unit 10K includes a photoreceptor 11K. Hereafter, the photoreceptors 11C, 11M, 11Y, and 11K may be collectively referred to simply as "photoreceptors." The exposure unit 112 is common to imaging units 10C, 10M, 10Y, and 10K. Each of the imaging units 10C, 10M, 10Y, and 10K may include its own separate exposure unit 112. In the following description, the exposure unit 112 is assumed to be common to each of the imaging units 10C, 10M, 10Y, and 10K. The imaging unit 110 and the intermediate transfer belt 120 form the toner image to be transferred to the recording medium. The charging unit uniformly charges the surface of the photoreceptor. The exposure unit 112 exposes the surface of the photoreceptor according to a specified image pattern, such as by laser writing, thereby forming an electrostatic latent image on its surface. The developing unit develops the electrostatic latent image formed on the photoreceptor as a toner image. The registration roller 170 adjusts the transport timing of the recording medium before it reaches the intermediate transfer belt 120. The intermediate transfer belt 120 transfers the toner image onto the recording medium. The fuser unit 500 performs the fixing process on the recording medium. Finally, the recording medium is discharged into the output tray. The detailed structu