Search

US-12619180-B2 - Heating device, fixing device, and image forming apparatus

US12619180B2US 12619180 B2US12619180 B2US 12619180B2US-12619180-B2

Abstract

A heating device includes a heater, a temperature sensor, an elastic body, and a receiver. The temperature sensor detects a temperature of the heater. The elastic body extends from one end to another end to press the temperature sensor against the heater at the one end in a pressing direction. The receiver has a contact face contacting and receiving said another end of the elastic body. The receiver covers the elastic body to conceal the elastic body from outside of the receiver. The receiver has a hole penetrating through the receiver on the contact face. Said another end of the elastic body is disposed adjacent to the hole, and a part of the elastic body is visible from the hole.

Inventors

  • Hitoshi Fujiwara

Assignees

  • Hitoshi Fujiwara

Dates

Publication Date
20260505
Application Date
20241212
Priority Date
20231218

Claims (20)

  1. 1 . A heating device comprising: a heater; a temperature sensor to detect a temperature of the heater; an elastic body extending from one end to another end to press the temperature sensor against the heater at the one end in a pressing direction; and a receiver: including a contact face contacting and receiving said another end of the elastic body; covering the elastic body to conceal the elastic body from outside of the receiver; and including a hole penetrating through the receiver on the contact face, wherein: said another end of the elastic body is disposed adjacent to the hole, a part of the elastic body is visible from the hole, the receiver includes a bent portion, and a distance L from the bent portion to the hole and a thickness T of the receiver satisfy the following expression, L >(½)× T.
  2. 2 . The heating device according to claim 1 , wherein: the hole faces a part of said another end of the elastic body.
  3. 3 . The heating device according to claim 1 , wherein: the hole is inside a region in which said another end of the elastic body contacts the contact face.
  4. 4 . The heating device according to claim 1 , wherein: the elastic body is a coil spring.
  5. 5 . The heating device according to claim 1 , wherein: a width of the hole is smaller than a width of said another end of the elastic body.
  6. 6 . The heating device according to claim 1 , wherein: the receiver includes multiple holes including the hole, and each of the multiple holes faces different parts of said another end of the elastic body.
  7. 7 . The heating device according to claim 6 , wherein: wherein the multiple holes are in a longitudinal direction of the receiver.
  8. 8 . The heating device according to claim 6 , wherein: wherein a distance between neighboring holes of the multiple holes is smaller than a width of said another end of the elastic body.
  9. 9 . The heating device according to claim 1 , wherein: the contact face of the receiver is flat.
  10. 10 . The heating device according to claim 1 , wherein: wherein the receiver includes a wall with the contact face and two bent portions at both ends of the wall.
  11. 11 . A fixing device comprising: the heating device according to claim 1 .
  12. 12 . An image forming apparatus comprising: the heating device according to claim 1 .
  13. 13 . The heating device according to claim 1 , wherein the receiver includes: a first wall; a second wall; and a third wall including the contact face.
  14. 14 . The heating device according to claim 13 , further comprising: a pressure roller, wherein the first wall and the second wall extend from the heater in a direction away from the pressure roller.
  15. 15 . The heating device according to claim 13 , wherein: the third wall extends in a direction intersecting the first wall and the second wall.
  16. 16 . The heating device according to claim 13 , wherein: the bent portion connects the first wall to the third wall.
  17. 17 . The heating device according to claim 13 , wherein the receiver further includes: another bent portion connecting the second wall to the third wall.
  18. 18 . The heating device according to claim 13 , wherein: the hole is a through hole that penetrates through the third wall.
  19. 19 . The heating device according to claim 1 , wherein: the receiver covers both sides of the elastic body in a direction intersecting the pressing direction.
  20. 20 . The heating device according to claim 1 , wherein: the elastic body is a metal coil spring.

Description

CROSS-REFERENCE TO RELATED APPLICATION This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2023-212947, filed on Dec. 18, 2023, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein. BACKGROUND Technical Field The present disclosure relates to a heating device, a fixing device, and an image forming apparatus. Related Art An image forming apparatus known in the art such as a copier or a printer includes a fixing device as an example of a heating device. The fixing device heats a sheet to fix an image onto the sheet. A typical fixing device includes a pair of rotators contacting each other to form a nip and a heater heating at least one of the rotators. After the heater heats one of or both rotators to a predetermined temperature, a sheet enters a nip between the rotators to apply heat and pressure to an unfixed image on the sheet, and the unfixed image is fixed onto the sheet. The fixing device includes a temperature sensor such as a thermistor or a thermostat that detects the temperature of the heater or the rotator in order to appropriately maintain the temperature of the heater and prevent an excessive temperature rise. SUMMARY This specification describes an improved heating device that includes a heater, a temperature sensor, an elastic body, and a receiver. The temperature sensor detects a temperature of the heater. The elastic body extends from one end to another end to press the temperature sensor against the heater at the one end in a pressing direction. The receiver has a contact face contacting and receiving said another end of the elastic body. The receiver covers the elastic body to conceal the elastic body from outside of the receiver. The receiver has a hole penetrating through the receiver on the contact face. Said another end of the elastic body is disposed adjacent to the hole, and a part of the elastic body is visible from the hole. This specification also describes a fixing device that includes the heating device and an image forming apparatus that includes the heating device. BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein: FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus; FIG. 2 is a schematic diagram illustrating a basic configuration of a fixing device; FIG. 3 is a plan view of a heater; FIG. 4 is a diagram illustrating a configuration of a temperature control mechanism of the heater; FIG. 5 is a diagram illustrating a configuration of the fixing device according to a first embodiment to illustrate the feature of the first embodiment; FIG. 6 is a side view of a part of a stay according to the first embodiment viewed from the outside of the stay to illustrate holes of the stay; FIG. 7 is a side view of the part of the stay of FIG. 6 to illustrate a coil spring displaced from a correct position; FIG. 8 is a schematic diagram illustrating an example of the stay rotated about an engaging portion of a heater holder to assemble the stay to the heater holder; FIG. 9 is a sectional view of the stay in the first embodiment to illustrate a distance from a bent portion of the stay to the hole; FIG. 10 is a side view of a part of the stay according to a second embodiment viewed from the outside of the stay to illustrate the hole of the stay; FIG. 11 is a side view of a part of the stay according to a third embodiment viewed from the outside of the stay to illustrate the hole of the stay; FIG. 12 is a side view of a part of the stay according to a fourth embodiment viewed from the outside of the stay to illustrate the hole of the stay; FIG. 13 is a side view of a part of the stay according to a fifth embodiment viewed from the outside of the stay to illustrate the holes of the stay; FIG. 14 is a side view of a part of the stay according to a sixth embodiment viewed from the outside of the stay to illustrate the holes of the stay; FIG. 15 is a schematic diagram illustrating a configuration of the fixing device according to a seventh embodiment; FIG. 16 is a schematic diagram illustrating a configuration of the fixing device according to an eighth embodiment; FIG. 17 is a schematic diagram of another fixing device in which the above embodiments are applicable; FIG. 18 is a schematic diagram of still another fixing device in which the above embodiments are applicable; FIG. 19 is a schematic diagram of still another fixing device in which the above embodiments are applicable; FIG. 20 is a diagram illustrating a configuration of the fixing device according to a comparative example; and FIG. 21 is a diagram of the fixing device of FIG. 20 to illustrate the coil spring inclined. The accompanying drawings are