JPS5823042A - Temperature controller of copying machine - Google Patents

Abstract

PURPOSE:To simplify constitution and to improve operability by performing temperature control and temperature compensation differing in purpose through single temperature detecting element. CONSTITUTION:The temperature detection output of a temperature detecting element 5, such as a thermistor having negative characteristics, is compared with comparators I2-I4 having the different threshold values and on the basis of comparison results, corresponding relays RA1-RA3, etc., are controlled to perform temperature compensation for temperature control, toner density control, power pack output control, etc., through a cooling fan motor. Since a number of dedicated temperature detecting elements, etc., are unnecessary, the number of parts is decreased and thus while the constitution of the temperature controller is simplified, operability of maintenance administration, etc., is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a temperature control device for controlling the temperature of each unit in a copying machine that is required to maintain a temperature within a set temperature range, such as a photoreceptor, a developing section, an exposing section, and a bonding section. The present invention relates to a temperature control device for a copying machine that also includes a temperature correction control device that takes density conditions into account when controlling donor replenishment in a developing section.

Conventionally, when performing these temperature controls, it has been common to use individual sensing elements for each.

However, in cases where each temperature control section is controlled by a plurality of temperature detection elements, each of which is provided exclusively for the purpose, it is necessary to control the dispersion in the performance of each temperature detection element, which requires maintenance and management. At the same time, the number of parts in the entire control device increases, and the configuration becomes complicated.
The disadvantage of poor workability cannot be avoided.

The present invention has been made in view of these shortcomings of conventional devices, and it simplifies the device and improves workability by performing multiple temperature controls and temperature correction controls for different purposes using a single temperature sensing element. The purpose is to measure the

As mentioned above, each unit and photoreceptor in the copying machine.

If the temperature of the halogen lamp, heat fixing device, etc. in the exposure area rises too much, for example, the photoreceptor will be susceptible to light fatigue, and the transfer sheet in the curved area may burn out. On the other hand, if the temperature is too low, the efficiency of each lamp will decrease, and the illuminance of halogen lamps will decrease.

Therefore, in the present invention, these temperatures are controlled by a cooling fan, and the cooling fan is turned on and off.
Further, as temperature correction control, output control of the power pack with respect to the charging current of the photoreceptor and toner concentration control of the developing section are performed.

Hereinafter, one embodiment of the present invention will be described in detail based on the illustrated embodiment.

Figure 1 shows the power batter, and the power pack l has a humidity sliding control input terminal 1B, an on-off human power terminal 1b, and an output terminal 1c, and an on-off input terminal lb.
&: When the "H" level is input, a high voltage output is output from the output terminal IC.

Further, as shown in the lt diagram, the output is controlled so that it becomes smaller as the control input voltage increases, and furthermore, it is controlled so that it becomes a constant value if there is no control input.

Fig. 111 is a schematic diagram showing a mechanism for detecting the toner concentration of the developer, in which a funnel 2 is arranged as shown in the figure in the developer storage IS (not shown), and the developer flowing downward through the funnel 2 is arranged. The toner concentration in the developer is detected by reading the change in inductance L using a film 3 in which the developer is wound around the outer part.

That is, if the toner concentration is low and the flow rate of the developer flowing through the sheet 2 is large, the amount of change in inductance L will be large.
If the toner concentration is high and the flow rate is small, the change in L will be small, but the ease with which the developer flows is influenced by the absolute humidity (approximately density, hereinafter explained as temperature) at the opening and opening, and the temperature increases. If the temperature is high, the developer will flow easily, and if the temperature is low, it will be difficult to flow. Therefore, the toner density must be controlled after making this temperature correction.

Figure 14 shows an F-ner concentration control circuit that takes temperature correction into consideration.Inductor system -DC:l>bark 4 is connected to coil 3, and this output is connected to the cosiparator! , so that it can be input to the input terminal C of the . The reference voltage of the comparator is the voltage at the hexagonal terminal.

1/- RA2 normally open contact, RA3 normally closed contact at temperature ah
It can be changed by turning it on and off using a correction control input. This comparator,
The output signal is a toner replenishment signal.

As shown in FIG. 5, the inductance-DC converter 4 has a characteristic such that as the inductance L increases, the output decreases. Comparator ■1 is V1$<V6
Then, the output becomes "H@ level". In this circuit, when the synergistic concentration becomes low and the developer flows easily, the output becomes "L" level.
As the value increases, Va decreases accordingly. Dry it
When cL<vb, the output of the comparator 11 is a Hl
``Toner replenishment is performed according to the level. By the way, as mentioned above, the ease with which the developer flows changes depending on the temperature, so in order to correct this, the reference voltages V61RAI and R
AIB is used to switch to 8 stages. Since L becomes higher than the toner concentration at high temperature, the normally open contact R
Turn on A2 and lower v6. On the other hand, since L is low relative to the toner concentration at low temperatures, the normally closed contact RAI is turned on to increase V&.

Sixth! ! ll is a temperature control circuit diagram showing the entire temperature control and temperature correction control. A thermistor with a negative characteristic is used as the temperature detection element 5, and this change signal is sent to the controller 7 (rater ■, circle) for controlling the cooling fan motor. terminal, said relay RAI
Koshino terminals for control (rate ■, ○ terminals and the relay R
It is designed to be applied to the (1) terminal of the regulator I4 for AJI control and the (C) fIA terminal of the comparator terminal for temperature correction control of the power back 1, respectively. Further, one input terminal of each of the comparators is the reference voltage of each converter 7 (lator), and by selecting this value, the wet coal at which the comparator starts operating is determined.

Q, , Q are transistors, and a relay circuit is used to control the cooling fan motor 6 on and off.

The operation of this circuit diagram will be explained below.

First, when the temperature goes higher than the reference value, the resistance value of the thermistor 5 becomes smaller, so the potential at the 0 point becomes lower, and the comparator! ! , 1. ．． The voltage at the ○ terminal of Il varies depending on the respective threshold levels, but is smaller than the reference voltage, so each cosciparator is turned on. Then, regarding the control of the cooling fan motor, the transistor Ql is turned on, the relay RAI is turned on, and the cooling fan motor 6 is energized, so the cooling fan motor 6 is operated and each unit is cooled. . On the other hand, in terms of toner density control, as mentioned above, when the output of the humpator I becomes "H" level, the relay RA
s is turned on, and the t quasi-voltage vb in FIG. 4 is lowered to perform temperature correction.

Funpaleta again! When the F transistor Q1 is turned on as , becomes "H" level, the power batter temperature correction input becomes the voltage across the thermistor 5 and is input to the power pack 1. As a result, since power back l has the characteristics as described above, comparator 1. Above the threshold, the output will change according to the temperature.

Conversely, when the temperature goes lower than the reference value, comparator 1
．． is turned on, and relay RAS is turned on.As described above, the toner density is corrected to correspond to the lower temperature.

As described above, the present invention can achieve its intended purpose because each temperature control and temperature correction control is performed using one temperature sensing element.

[Brief explanation of the drawing]

111iU is a simplified diagram showing the power pack, ms diagram is the characteristic diagram of the power pack, #! FIG. 3 is a mechanism diagram for detecting the concentration of the energizer, FIG. 5... Temperature detection element, 6... Cooling fan motor. 71 4 tamsai 6 kaku

Claims (1)

[Claims] (1) A copying machine characterized by using a single temperature detection element and performing temperature control and temperature correction control of each unit inside the copying machine according to the temperature detected by this temperature detection element. Temperature control device. (jl A copy of claim 11, characterized in that the output direction of the cooling fan motor is controlled as one-time control, and the toner concentration control and power pack output control are performed as temperature correction control.) Machine temperature control device.