JP3199583B2 - In-machine temperature control method for image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to temperature control in an apparatus for forming an image using an electrophotographic process, such as a copying machine and a printer. In particular, the present invention relates to control of an in-machine cooling fan motor for heat generated by a heat fixing device.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using a heat fixing device, the temperature of a heat fixing roller or the like becomes high due to heat fixing at the time of copying and printing. And the cooling fan is driven to forcibly lower the temperature inside the machine to reduce the thermal effects on various parts and equipment. However, at the time of resuming printing, it is necessary to quickly energize the heat fixing unit, and thus it is difficult to energize the thermal fixing unit and to operate the cooling fan at a proper timing. In addition, since driving a fan motor also causes noise, there are complaints about driving the fan motor unnecessarily in a quiet office environment, and the optimal control including the viewpoint of power consumption is examined. ing.

[0003] Japanese Patent Publication No. Sho 62-26466 discloses that if the heater is left for a certain period of time after the warm-up of the heater when the power is turned on or after the copying operation is completed, the power supply to the heater is cut off. A technique is described in which if the heater is left undisturbed for a certain period of time after the power supply to the heater is cut off, this is detected and the body cooling fan is stopped. Conventionally, for example, control as shown in FIG. 3 has been performed. In FIG. 3, in the case of A, the fan motor rotates when the heater power is turned on, the heater changes from the print state to the ready state, and after a lapse of a predetermined time T4, the power supply to the heater and the fan motor is stopped. It is. In the example B, the fan motor is controlled to rotate at a high speed and the heater is heated to a high temperature in a print state, and the fan motor is controlled to rotate at a low speed and a heater to a low temperature during a ready state.
After a lapse of a predetermined time T4 from the ready state, the power supply to the heater and the fan motor is stopped.

[0004]

However, in the prior art, a cooling fan motor is provided in a copying operation standby state (ready state) apart from when the image forming system is operating (copying or printing). Since the motor is driven, fan noise is generated, and noise, contamination inside the machine in which dust floats by the fan, and waste of power due to driving of the fan motor occur. On the other hand, when the driving of the fan motor is stopped in the ready state, it is difficult to keep the temperature inside the apparatus constant. Particularly, depending on the operating temperature environment, if the control of the internal temperature is fixed at a predetermined time, there is a problem that the above-described problem cannot be sufficiently satisfied.

An object of the present invention is to solve these problems of the prior art, and to provide an apparatus capable of arbitrarily controlling the temperature inside the machine according to the use environment.

[0006]

In order to achieve the above object, the present invention provides a heat fixing means for fixing an unfixed toner image on recording paper by a heater, and a cooling fan provided for cooling the inside temperature of the apparatus. An image forming apparatus comprising at least a fan motor for driving the fan motor, the timer for starting counting after the image forming operation is completed, the rotation speed of the fan motor is reduced for a first set time, and the heater temperature is set to a standby temperature. And a second set time set to stop the low-speed rotation drive of the fan motor and maintain the standby temperature after the first set time including the first set time. The second stage and the fan mode
And a third stage of maintaining the power saving mode in which the power supply to the heater and the power supply to the heater are stopped. The second setting time is divided into a fixed portion and a variable portion, and the variable time can be arbitrarily set for the variable portion. did.

[0007]

According to the temperature control method of the present invention, since the time of the power saving mode can be set arbitrarily, power saving of the apparatus, prevention of noise, and prevention of contamination inside the apparatus can be achieved according to the use environment.

[0008]

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

In the drawings, the same parts are indicated by the same reference numerals.

FIGS. 1 and 2 show a temperature control method according to an embodiment of the present invention. FIG. 1 is a timing chart showing a heater and cooling fan control method of the present invention, and FIG. FIG. 2 is a block diagram of a main part of the image forming apparatus.

Reference numeral 1 denotes a heater such as a heat-fixing roller serving as a heat-fixing unit. The control unit 2 controls a heating temperature to a fixing-possible temperature, a standby temperature, and a sleep mode temperature for power saving by turning on / off and supplying a current. Controlled.
The control unit 2 has a microprocessor 3 and an input / output port 4. Reference numeral 5 denotes a table storage unit including a control program for the control unit to perform control, various time setting storage units, and driver selection data. The data written to the time setting storage means of the table storage means 5 can be arbitrarily rewritten. This rewriting is performed by the sleep mode on / off time varying means 6.
Done through. Numeral 7 is a cooling fan for cooling the inside of the machine which has been heated to a high temperature by the heater 1. The cooling fan 7 is controlled by the cooling fan driving means 8, but multi-stage control for switching the rotation of the cooling fan between high-speed rotation and low-speed rotation is improper. It has become. The control is also performed by the control unit 2 as described above.
Is controlled by

The operation mode of the heater 1 and the cooling fan 7 is such that the heater 1 is maintained at a high temperature at which the print state can be fixed, the print mode in which the cooling fan 7 rotates at a high speed, and the heater 1 can be fixed in a print standby state. A ready mode in which the temperature is maintained at a temperature lower than the temperature, the fixing temperature is raised according to the print command, and the cooling fan 7 is stopped after a low-speed rotation for a predetermined time, the power supply to the cooling fan 7 and the heater 1 is stopped, and the control unit and display A power-saving sleep mode that only supplies power to the unit is provided. The switching timing of these modes is controlled by the control unit 2. For example, the printer normally enters the ready mode after printing is completed. At this time, after a predetermined time (for example, 2 minutes) elapses, the time T1 for performing low-speed rotation until the rotation of the cooling fan 7 is stopped.
And the ready state time is set to T2 (for example, 15
Minutes). At this time, T2 is the time from the end of printing until the sleep mode is entered. According to the present invention, the ready mode time T3 can be arbitrarily variably added to the fixed portion T2, The T3 time is set as needed, and the time to enter the sleep mode is controlled. Here, the sleep mode is a mode necessary for operating the control unit 2, the display unit, and the like.
The power other than the V system is turned off, and the power supply to the heater and the cooling fan is stopped. That is, by controlling the ready mode time and arbitrarily setting the time to enter the sleep mode, the set value can be freely changed according to the user's preference. Here, T2 is a factory initial setting T according to preference of a factory initial setting and a sleep setting.
Only when the value exceeds 2, the time that is exceeded is defined as T3 (the shaded portion described above).

[0013]

As described above, according to the configuration and the method of the present invention, the power supply to the heater and the rotation of the cooling fan are controlled by adding a controllable time to the printing time, so that noise can be reduced. Reduction, reduction of dust, and power consumption can be achieved. In addition, wasteful power consumption other than during the printing or copying operation can be significantly reduced, the rise in the internal temperature can be suppressed, and noise during the ready state can be reduced.

[Brief description of the drawings]

FIG. 1 is a timing chart showing a method for controlling a heater and a cooling fan according to the present invention.

FIG. 2 is a block diagram of a main part of the image forming apparatus of the present invention.

FIG. 3 is a timing chart showing a conventional heater and cooling fan control method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater 2 Control part 3 Microprocessor 4 I / O port 5 Table storage means 6 Sleep mode on / off time variable means 7 Cooling fan 8 Cooling fan drive means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-81058 (JP, A) JP-A-4-2977893 (JP, A) JP-A-6-102793 (JP, A) JP-A-3- 122677 (JP, A) JP-A-59-152475 (JP, A) JP-A-56-92559 (JP, A) JP-A-62-269166 (JP, A) JP-A-7-114292 (JP, A) JP-A-7-28356 (JP, A) JP-A-5-281878 (JP, A) JP-A-5-323710 (JP, A) Japanese Utility Model Application No. 64-34634 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 21/20 G03G 15/20 109 G03G 21/00 370-540

Claims (1)

(57) [Claims] An image forming apparatus comprising at least a heat fixing means for fixing an unfixed toner image on recording paper by a heater, and a fan motor for driving a cooling fan provided for cooling the inside temperature of the apparatus. A first stage of a ready state in which the rotation speed of the fan motor is reduced for a first set time by a timer which starts counting after the end of the image forming operation, and the heater temperature is maintained at a standby temperature; A second stage having a second set time set so as to stop the low-speed rotation drive of the fan motor after the first set time has elapsed and to maintain the standby temperature, and to drive the fan motor and energize the heater. The second set time is divided into a fixed part and a variable part, and a variable time can be set arbitrarily for the variable part. Internal temperature control method for an image forming apparatus characterized by.