JPS61126571A - Method for controlling electric power of copying machine - Google Patents

Abstract

PURPOSE:To operate effectively plural pieces of heaters and to obtain required calorific value by providing a control means for calorific value which detects the temp. of a fixing part and discriminates the number of the heaters to be lighted and a control means which selects the heaters to be lighted in accordance with the discrimination output of said control means for the calorific value and lights the selected heaters and an illuminating lamp for exposing at different phase angles. CONSTITUTION:A lamp regulator 3 turns on a lamp 2 from the zero cross point on the side where the period of an AC power source 1 starts up to the phase angle corresponding to the quantity of light set by a variable resistor 4. Said regulator outputs a firing end signal OA at the point of the time when firing ends. On the other hand, a microcomputer 8 outputs a heater on signal S2 by each signal from a temp. control part 7. The microcomputer outputs a heater firing signal HA to the heater regulator 5 at the prescribed phase angle to light up the heaters Hl-Hn selected by the heater selection signal HS when the microcomputer receives the signal OA which the heaters to be lighted by the heater selection signal are held selected.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a power control method for a copying machine equipped with a plurality of fuser heaters, and in particular, generates the necessary amount of heat by flexibly selecting the fuser heaters to be turned on. The present invention also relates to a power control method for a copying machine that can extend the life of a heater.

[Prior Art] In recent years, high-speed copying machines with a copying process speed of 60 sheets per minute or more have been put into practical use. In such a copier.

In order to supply a sufficient amount of heat to the transfer paper that moves at high speed, it is necessary to increase the output of the fixing section.

In order to increase the output of the fixing section, it is sufficient to install one high-output heater, but such a heater is expensive.
A plurality of relatively low-output heaters (for example, a heater used in a fixing section of a normal copying machine) may be provided.

In copying machines, the heat load on the fixing section may change, for example, during standby and during operation.

It is necessary to change the amount of heat generated by the heaters in response to this, but if the heaters are turned on randomly, the instantaneous current may become excessive, which may introduce noise into the control system.

[Objective] The present invention has been made in view of the above-mentioned actual state of the prior art, and provides a power control method for a copying machine that can effectively operate a plurality of heaters to obtain the necessary amount of heat. The purpose is to

[Configuration] In order to achieve this object, the present invention includes a heat generation amount control means that detects the temperature of the fixing section and determines the number of heaters to be turned on, and a heat generation amount control means that determines the number of heaters to be turned on based on the determined output of this heat generation amount control means. The apparatus includes a control means for selecting a heater to be used, and for lighting the selected heater and the exposure illumination lamp at different phase angles of the power supply.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the invention. In this embodiment, n heaters are provided in the fixing section, and the light source of the exposure section is energized beforehand, the heater is energized afterward, and the light source and heater are ignited so that they are not turned on at the same time. It controls the angle.

In the figure, 1 is an AC power supply, 2 is an illumination lamp that serves as a light source for the exposure section, and 3 is an illumination lamp 2 that is turned on with a predetermined amount of light at the timing when a lamp-on signal Sl is applied from a microcomputer 8, and the lighting of the lamp 2 is ended. At the same timing, the microcomputer 8 sends the ignition end signal 0m.
A lamp regulator 4 is a variable resistor that sets the amount of light emitted from the illumination lamp 2 to the lamp regulator 3.

5 lights up the heaters H1-Hn set by the heater selection signal H5 applied from the microcomputer 8 from the timing when the heater ignition signal HA is applied from the microcomputer 8 to the zero cross point of the AC power supply, and also outputs the heater monitor signal MH1. =Heater H by NHn
1-Hn that is currently in use is microcomputer 8
6 is a temperature detector that detects the temperature of the fixing section; 7 is a heater lighting signal H based on a comparison between the output of the temperature detector 6 and the set temperature (heat amount) of the fixing section.
This is a temperature control section that outputs the O1 single lighting signal SS and the multiple lighting signal SH to the microcomputer 8.

The microcomputer 8 outputs a lamp-on signal S1 to the lamp regulator 3 at a predetermined timing, and also outputs a heater-on signal S2 to the heater regulator 5 when the heater lighting signal HO is applied from the temperature control section 7. Single lighting signal SS, multiple lighting signal SR and heater regulator 5 applied from control unit 7
A heater to be turned on is selected based on H1=MHn based on the heater monitor signal applied from , and the result is output to the heater regulator 5 as a heater selection signal H8. Also,
The microcomputer 8 constantly monitors the heater monitor signals MHI to MHn output from the heater regulator 5, calculates the cumulative lighting time of each heater H1 to Iin, and averages the heater old -Hn as described later. By using the heaters H1 to In, the lifespan of each heater H1 to In is made to be approximately the same. The microcomputer 8 constitutes the main body control section of the copying machine, and other elements of the copying machine are also controlled by the microcomputer 8.

Now, basically, the microcomputer a is in a state where the heater lighting signal HO is being output from the temperature control section 7.
When the individual lighting signal SS is output from the temperature control section 7, the one with the shortest cumulative lighting time is determined from among the heaters H1 to Hn, and outputted to the heater regulator 5 as the heater selection signal H5.

When a plurality of lighting signals SR are outputted from the temperature control section 7, a predetermined number of heaters are determined from the one with the shortest cumulative lighting time and outputted to the heater regulator 5 as a heater selection signal HS.

Note that the cumulative lighting time is accumulated every second and determined in minutes or hours. In addition, during non-copying operation, if the temperature control unit 7 outputs the individual lighting signal SS, the microcomputer 8 may repeatedly perform the comparison process of the cumulative lighting time every unit time, and If cumulative output data in which output elements are weighted by time is used instead of cumulative lighting time, the lifespan can be determined more accurately.

With the above configuration, the lamp 2 is controlled by the microcomputer 8.
and the lighting control of the heater old -Hn in Figures 2(a) to (
This will be explained with reference to g).

The microcomputer 8 outputs a lamp-on signal Sl (see FIG. 2(a)) to the lamp regulator 3 at a predetermined timing in the copying process.

As a result, the lamp regulator 3 turns on the lamp 2 from the zero-cross point on the cycle start side of the AC power source 1 to the phase angle corresponding to the light amount set by the variable resistor 4, see FIGS. 2(b) and 2(c). ), and outputs an ignition end signal OA when the ignition is completed (see FIG. 2(d)).

On the other hand, the microcomputer 8 receives a heater-on signal 52 (see FIG. 2(a)) based on each signal from the temperature control section 7.
is output and the heater to be turned on is selected by the heater selection signal Hs, and when the ignition end signal OA is received as described above, the heater ignition signal HA is outputted to the heater regulator 5 at a predetermined phase angle. 2 (f)), the heater selected by the heater selection signal I (s!
(Turn on 1 to In (see Figure 2 (g)).

In this way, the lamp 2 and the heater old-In are turned on at different timings, so the protrusion current is small, and no noise is generated in the power supply, causing an abnormality in the control system (in this case, the microcomputer 8). will not occur.

By the way, in order to output a predetermined amount of light with the lamp 2 and to generate the amount of heat necessary for fixing with the heaters H1 to In,
The ignition angles of lamp 2 and heater [1-Hn are set as follows.

For example, if the ratings of lamp 2 and heaters H1 to Hn are 85V-5001 and 100V-9601, respectively, the third
From the figure, the firing angle required to light lamp 2 is 11
0 degree, therefore, the heaters old to Hn can be fired at a maximum phase angle of 70 degrees, and the effective voltage supplied to the heaters H1 to Hn at this time is 53V from the same figure, so the output Po for each heater is becomes like a linear expression.

PFC rated output power ψ ([effective voltage]/[rated voltage]) -
Fist 1.54 = 960 umbrellas (53/100) Umbrella -1,5
4=360 (41') However, the umbrella is an operator for multiplication, and the ψ umbrella is an operator for exponentiation.

From 29, the number of heaters required to generate the amount of heat required for the fixing section can be calculated.

Alternatively, 1.For example, if the output of the fixing unit is kept constant at 500V, it is sufficient to turn on two heaters at 250V.In this case, the effective voltage required for the heater is 42V.
Therefore, from Fig. 3, the phase angle is about 60 degrees. Therefore, in this case, the microcomputer 8 outputs the heater ignition signal HA with a phase angle delay of about 10 degrees from the timing at which the ignition end signal OA is input.

Further, the temperature control unit 7 calculates the amount of heat generated by the fixing unit from the output of the temperature detector 6, further calculates the difference between the value obtained as a result and a predetermined amount of heat, and compensates for the deficiency. Instead of the multiple ignition signal SH, a signal indicating the number of heaters to be lit may be output.

In the above-described embodiment, the lamp 2 is first energized and the heater old -Hn is later energized, but the energization timing may be reversed.

[Effects] As described above, according to the present invention, there is a heat generation amount control means that detects the temperature of the fixing section and determines the number of heaters to be turned on, and one lighting amount based on the determined output of this heat generation amount control means. It is equipped with a control means that selects the heater to be used and lights up the selected heater and the exposure illumination lamp at different phase angles of the power supply, so multiple heaters can be operated effectively to obtain the required amount of heat. be able to.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing an embodiment of the present invention, Figures 2 (a) to (g) are waveform diagrams for explaining the operation of the device shown in Figure 1, and Figure 3 is an ignition diagram. It is a graph diagram for explaining corners. DESCRIPTION OF SYMBOLS 1... AC power supply, 2... Lamp, 3... Lamp regulator, 4... Variable resistor, 5... Heater regulator, 6... Temperature detector, 7... Temperature control section ,
8...Microcomputer, Hl-In...Heater.

Claims (1)

[Claims] In a power control system for a copying machine equipped with a plurality of fixing heaters, a temperature detector detects the temperature of a fixing section, and a heat generation control means determines the number of heaters to be turned on based on the output of the temperature detector. , a copying machine characterized by comprising control means for selecting a heater to be turned on based on the determined output of the heat generation amount control means, and for lighting the selected heater and an exposure illumination lamp at different phase angles of the power supply. power control method.