JPH079163Y2 - Fixer controller for copier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a fixing device control device for a copying machine.

[Conventional technology]

As is well known, in an electrophotographic copying machine, image light obtained by scanning a document is incident on a photosensitive drum to form an electrostatic latent image, and the electrostatic latent image is developed with toner and then recorded on recording paper. Transfer
After that, the fixing is performed by a roller fixing device or an oven fixing device having a surface temperature of about 180 ° C.

In such a fixing device of a copying machine, there is a fixing device in which a heat source is divided into a plurality of parts and each heat source is individually controlled in order to make the temperature distribution uniform.

FIG. 2 is a circuit diagram showing a conventional configuration of the heat source division type fixing device control device. Triacs 2A and 2B are connected to two heat sources 1A and 1B, and on / off control of the triacs 2A and 2B is performed. Is configured to supply AC power from the AC power supplies 3A and 3B.

The triacs 2A and 2B are controlled by fixing device control devices 4A and 4B provided corresponding to the triacs 2A and 2B, respectively. Although only one fixing device control device 4A is shown in detail in FIG. 2, the temperature sensor 40 for detecting the temperature of the heat source 1A and the input current and the input voltage for the heat source 1A are multiplied to detect the input power. The electric power detection circuit 41 and the temperature detected by the temperature sensor 40 are compared with the reference temperature at which fixing is possible, and if the temperature of the heat source 1A becomes lower than the reference temperature, the input power corresponding to the fixing reference power is the heat source 1A. And a control circuit 42 for controlling the triac 2A so as to be supplied to the TRIAC 2A.

In this configuration, assuming that the total power used by the heat sources 1A and 1B is PKW, P / 2KW of power is supplied to each heat source 1A, 1B while the fixing reference temperature is not reached. As a result, the necessary fixing temperature is secured.

That is, if the two heat sources 1A and 1B have not reached the fixing reference temperature, power of P / 2KW is supplied to both heat sources, and if only the heat source 1A reaches the fixing reference temperature over time. , Stop the power supply to the heat source 1A,
It is configured to continuously supply P / 2KW of power to 1B only.

[Problems to be solved by the invention]

However, the surface temperature of the fixing roller does not rise uniformly due to an error in the temperature rise characteristic of the heat source. Therefore, as described in the above conventional configuration, when the electric power supplied to each heat source is constant (= P / 2KW), the heat source with a slow temperature rise has to wait until the fixing reference temperature is reached. There is a problem that it takes time to reach a fixable state. In addition, since it is necessary to arrange the control circuits in the number equal to the number of divisions of the heat source, there is a problem that the cost becomes high.

An object of the present invention is to provide a fixing device control device for a copying machine, which has an inexpensive structure and is capable of fixing in a short time.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention divides a heat source for fixing into a plurality of heat sources, and for each heat source, a temperature sensor for detecting the temperature of the heat source and a power detection for detecting the input power of the heat source. And a temperature sensor detects that all the temperatures of the heat sources are below a predetermined fixing reference temperature, the power detected by the power detecting means is allocated to each heat source. The electric power supplied to each heat source is controlled so that the maximum electric power is reached, and when the heat source reaching the fixing reference temperature is detected by the output of the temperature sensor, the temperature of the heat source is maintained at the fixing reference temperature. In order to ensure that the electric power detected by the electric power detection means is a predetermined percentage of the maximum electric power, the electric power supplied to the heat source is controlled by the fixing device control device of the copying machine. When a heat source that is equal to or lower than the fixing reference temperature is present, surplus power of the heat source that has reached the fixing reference temperature is supplied to the heat source that is equal to or lower than the fixing reference temperature, thereby lowering the fixing reference temperature or lower. It is characterized in that the time taken for the heat source to reach the fixing reference temperature is shortened.

[Action]

In this invention, when there is a heat source that has reached the fixing reference temperature and a heat source that is equal to or lower than the fixing reference temperature, surplus power of the heat source that has reached the fixing reference temperature is supplied to the heat source that is equal to or lower than the fixing reference temperature.

For example, the heat source is divided into two, and the maximum value of the power used by these two heat sources (If the limit value of the power used is PKW, the temperature of these two heat sources does not reach the fixing reference temperature. In this case, P / 2K for each of these two heat sources
W power is applied. When the temperature of one heat source reaches the fixing reference temperature, the electric power applied to this heat source is controlled to a predetermined percentage of P / 2KW, for example 60%, in order to maintain the temperature of this heat source at the fixing reference temperature. The surplus power of the heat source controlled to 60%, that is, 40% of the power of P / 2KW is added to the power of P / 2KW. As a result, the temperature of the other heat source that has not reached the fixing reference temperature can be rapidly increased, and the time for the overall temperature to reach the fixing reference temperature is accelerated.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention.
An example in which the heat sources 1A and 1B are divided is shown.
In the figure, 40A and 40B are temperature sensors for detecting the temperatures of the heat sources 1A and 1B, respectively, and the output signals thereof are amplifiers 43A and 43B.
After being amplified by, it is input to the companders 44A and 44B and compared with the reference temperature signal which is in a fixable state. Then, the signal of the comparison result is input to the microprocessor 46 via the input circuit 45. On the other hand, 47A, 47B
Is a transformer that detects the voltage supplied to the heat sources 1A and 1B, and 48A and 48B is a current transformer that detects the current supplied to the heat sources 1A and 1B. The signals of the input voltage and the input current to the heat sources 1A and 1B detected in (4) are input to the peak hold circuit 49, and their respective peak values are detected. The detection signal of the peak hold circuit 49 is
Converted to a digital value in AD converter 50 and input circuit
Input to the microprocessor 46 via 45.

The microprocessor 46 temporarily stores the read-only memory (ROM) 51 storing the control program and the temperature signal, the voltage signal, and the current signal input from the input circuit 45 in order to control the power supplied to the heat sources 1A and 1B. And a random access memory (RAM) 52 for doing so.

In the above configuration, if the maximum value of the power used by the heat sources 1A, 1B (limit value of the power used) is 2 KW, if the temperature of the heat sources 1A, 1B is lower than the reference temperature, the comparator 44
A and 44B output a comparison result signal of "heat source temperature <reference temperature", and input this signal to the microprocessor 46. For this reason, the microprocessor 46 uses the "heat source temperature <reference temperature"
As long as the relationship is satisfied, the triacs 2A and 2B are always turned on, and control is performed so that 1 KW of AC power is input to each of the heat sources 1A and 1B.

When the temperature of the heat sources 1A and 1B rises and exceeds the reference temperature after a fixed time, the comparators 44A and 44B output the comparison result signal of "reference temperature <heat source temperature".
Therefore, the microprocessor 46 turns off the triacs 2A and 2B to stop the supply of AC power to the heat sources 1A and 1B. However, after a lapse of a certain period of time, the temperatures of the heat sources 1A and 1B decrease, so that the comparators 44A and 44B again output the comparison result signal indicating the relation of “reference temperature> heat source temperature”. Turns on the dryacs 2A and 2B again, and controls so that AC power of 1 kW each is supplied to the heat sources 1A and 1B.

In this way, the triacs 2A and 2B are repeatedly turned on / off, and the temperatures of the heat sources 1A and 1B are maintained at the reference temperature without supplying 100% of 1 KW AC power. In this case, if the paper to be fixed is transferred, the temperature will drop during fixing, but even if the paper to be fixed is transferred, the power usage rate per fixed time for maintaining the reference temperature is 60%. (= 600W)
Then, the microprocessor 46 uses the comparators 44A, 44
If the ON / OFF ratio is less than 60% according to the ON / OFF information of the heat source indicated by the comparison result signal of B, it is determined that the fixing temperature is sufficiently maintained, and the ON / OFF is determined. When the ratio becomes 60% or less, for example, the triac so that the power supply to the heat source 1A becomes 60% (= 600W)
Control 2A.

On the other hand, if the on / off ratio of the heat source 1B is not lower than 60%, 40% of the electric power (= 400W) that is no longer needed in the heat source 1A is added to the power supply of the heat source 1B, Total 1.4KW
The triac 2B is controlled so that the electric power of is supplied.

That is, the microprocessor 46 changes the ratio of the power supplied to each heat source according to the deviation of the heat source temperature from the fixable temperature. As a result, a larger amount of electric power than usual is supplied to the heat source whose temperature rises slowly, the temperature rise is accelerated, and the time required to reach the fixable state is shortened.

If the on / off ratio of the heat source 1B also becomes 60% or less, both the two heat sources will be driven with 60% electric power (600W).

[Effect of device]

As is apparent from the above description, according to the present invention, the ratio of the power supplied to each heat source is changed according to the temperature rise characteristics, and the power larger than usual is supplied to the heat source having a slow temperature rise. Therefore, it is possible to shorten the time required to reach the fixable state. Further, since the temperature control is performed by the control circuit common to each heat source, the configuration is simple and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of a conventional control device. 1A, 1B …… heat source, 2A, 2B …… triac, 3A, 3B …… AC power supply, 40A, 40B …… temperature sensor, 44A, 44B …… comparator, 45 …… input circuit, 46 …… microprocessor, 47
A, 47B: Transformer, 48A, 48B: Current transformer, 49 ... Peak hold circuit, 50 ... AD converter, 51 ... Read-only memory, 52 ... Random access memory.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-177581 (JP, A) JP-A-59-95563 (JP, A) JP-A-61-134775 (JP, A) JP-A-51- 9841 (JP, A) JP 51-127742 (JP, A) JP 57-124362 (JP, A) JP 57-196278 (JP, A) JP 58-106583 (JP, A) JP-A-60-249175 (JP, A) JP-A-53-115237 (JP, A) JP-A-54-641 (JP, A) JP-A-50-160042 (JP, A) JP-A-51-46951 (JP, A) Actually open Sho 57-112357 (JP, U) Japanese Patent Sho 61-1754 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A heat source for fixing is divided into a plurality of heat sources, and
For each heat source, a temperature sensor that detects the temperature of the heat source and a power detection circuit that detects the input power of the heat source are arranged, and all the temperatures of the heat source are below a predetermined fixing reference temperature. When detected by the temperature sensor, the electric power supplied to each heat source is controlled so that the electric power detected by the electric power detection means becomes the maximum electric power allocated to each heat source, and the output of the temperature sensor When a heat source that has reached the fixing reference temperature is detected by, the electric power detected by the electric power detecting means for maintaining the temperature of the heat source at the fixing reference temperature becomes a predetermined percentage of the maximum electric power. In the fixing device control device of the copying machine for controlling the electric power supplied to the heat source, if the heat source that has reached the fixing reference temperature exists and the heat source that is equal to or lower than the fixing reference temperature exists, Fixing of a copying machine characterized by shortening the time for the heat source below the fixing reference temperature to reach the fixing reference temperature by supplying surplus power of the heat source reaching the fixing reference temperature to the heat source below the fixing reference temperature. Control device.