JPS61207147A - Image former - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an image forming apparatus that uses current from a charger and a secondary battery as a power source.

[Prior art]

In a conventional image forming apparatus 1, such as a copying machine, the power source is a series regulator CR as shown in FIG.
The electronic circuit of the switching regulator SR shown in FIG. However, it goes without saying that such electronic circuit power sources cannot be used in places where AC power is not available. Recently, there has been a remarkable growth in the personal field of copying machines, and there is a trend towards miniaturization and weight reduction, and the conventional electric configuration of small copying machines is as shown in FIG. 11, for example. To describe its configuration, P is the power plug, NF is the noise filter, and S is the door switch.

M is the main motor, LA is the halogen lamp that is the light source for exposing the original, UL is the lamp regulator that controls the lighting voltage of the lamp LA, FM is the fan motor for absorbing waste heat and ozone within the machine, and H is the fixing heater. , Q is a triac that controls switching of electricity to the heater H, and a DC
P is DC power supply.

Lja is an AC drive element unit that controls AC loads such as the main motor M and the lamp LA, US is an operation unit through which the operator inputs the copy mode, etc., and Uc is
This is a DC control unit that judges input information from an operator and performs sequence control of copying operations. Note that Vdc is a DC power supply voltage.

However, the conventional copying machine as described above,
Since the power consumption of the halogen heater H and the halogen lamp LA is large, there is a drawback that they are not suitable for a battery-powered copying machine embodying the present invention.

〔the purpose〕

The present invention has been made in view of the above-mentioned circumstances, and by configuring an AC power supply circuit with a charger and a secondary battery in series, an image forming apparatus that can operate regardless of the presence or absence of an AC power supply is provided. is intended to provide.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

First, the general structure will be described.

In the configuration diagram shown in the first factor, P is a power plug for introducing AC power, NF is a noise filter, S is a door switch, 1 is a charger connected to the AC power supply circuit Ac, and 2 is a 2
The next battery, 3, is a charging circuit. 4 is a feedback circuit from the battery 2 to the charger 1, Da is a DC power supply circuit from the secondary battery 2, and SL is a main switch provided in the power supply circuit Da, which is turned ON when the device is in use. Also, D
1 is a reverse current prevention diode provided in front of the main switch S of the circuit Da; 5 is a diode connected from the e output terminal of the charger 1 to the power supply circuit OC between the diode D and the main switch S; It is an output circuit that is led and connected to. Further, Ul is a DC control unit connected to the DC power supply circuit Da, Ut is a drive control circuit unit that operates a high-efficiency DC motor M, FL is an 18W fluorescent lamp as a document exposure light source, U3 is a high frequency lighting device for the fluorescent lamp FL.

In addition, a nickel-cadmium battery (hereinafter referred to as a "nickel-cadmium battery") is adopted as the secondary battery 2, and the configuration of the secondary battery 2 is as shown in FIG. Connected in series for 24V. Also,
The NiCd battery 2, which is a storage battery, is for large discharge.

Allocate one that supports quick charging.

Since a pressure fixing method is adopted as a fixing method for copying, the fixing heater H required in the conventional heat fixing method is unnecessary.

Next, the status of the charging sequence of the secondary battery 2 will be described based on FIG.

As shown in Figure 1, the consumption type l of the copying machine according to the present invention is 24V, 4A during copying, and a maximum of 0.2 people during standby.

Further, during copying, the charging current 1 that is charged to the secondary battery 2 through the internally provided backflow prevention diode D shown in FIG. ,
During standby, as shown in Fig. 4, the IA is applied until the full charge voltage Vm is reached, and after that, the 5-hour rate rated capacity of the NiCd battery 2 is (1/10) Cf/1,200 mA h.
) Charge at 120mA. At this time, the current consumption 1 of the DC load is supplied from another output f of the charger 1 via the output circuit 5, as shown in FIG.

Therefore, during copying, a constant charging current of 1.
The discharge current 12 from one person and the discharge current 12 from the three people from the secondary battery 2 is combined and supplied to the load as a consumption current 1 of 4A.On the other hand, during standby.

The secondary battery 2 enters a charging-only state and can reduce the input current from the AC power source. In addition, as another configuration of the present invention, as shown in FIG.
It is also possible to obtain one of the output currents H passing through the output circuit 5 from another output vr.

Note that the full charge voltage Vm of the NiCd battery 2 has temperature dependence, so as shown in FIG. 6, the full charge voltage Vm tends to decrease as the temperature rises. Therefore, it is inappropriate to set the full charge voltage Vm at a fixed value, and according to the present invention, as shown in FIG. 7, which will be described later, the full charge voltage Vm is is controlled.

Next, the charger 1 will be described with reference to FIG.

This charger 1 employs a switching regulator because it is more advantageous than the series regulator CR in terms of space saving and heat generation.

On the secondary side of the inverter transformer T1, a diode D3
After full-wave rectification and smoothing by D4 and capacitor C7, 5DC-DC conversion is performed by regulator ICQ to DC35.
I'm getting V. And charging current 1 is 0 of relay RL,
For N10FF, as shown in Figure 4, the relay RL
, is controlled by IA during the ON period, and 120 mA during the OFF period. This relay RL, 0N10FF
' is controlled by the comparator Q4, and a signal for monitoring the battery voltage Vcc divided by the resistor R65R1 is input to the positive input with respect to the reference voltage Vf at the negative input. Further, TH is a thermistor for detecting ambient temperature, which performs temperature correction of the full charge voltage Vm as described above. That is, when the ambient temperature is low, the resistance value of the thermistor TH is large, so that the comparator Q4
The charger output voltage v1 when the positive input voltage Vc of the thermistor TH matches the reference voltage Vf is 1.
It becomes larger compared to when the resistance value of 1 is small. As a result, the full charge detection voltage of the secondary battery 2 is set to a higher value as the ambient temperature is lower, and satisfies the charging characteristics of the secondary battery 2 shown in FIG.

Note that during copying, as shown in FIG. 3, even when the secondary battery 2 is fully charged, a large current of 3A flows out, causing the battery voltage VCC to drop due to the internal resistance Rs of the battery 2 itself. The output voltage 1 also decreases, so the input voltage relationship of the comparator Q4 becomes Vf)Vc, and the relay RL is reliably set to O.
It is considered N. Therefore, the charging current 1, which was 120 mk when the relay RL was OFF, becomes IA since the resistor R8 is excluded.

Furthermore, the present invention assumes a case where copying is frequently used and over-discharge occurs.

As shown in FIG. 2, when the battery voltage Vcc drops below the predetermined level voltage Vb, the copying operation is stopped or prohibited to prevent deterioration of the secondary battery 2, and the battery 2 reaches full charge again. Later, copying was permitted (the detailed circuit is not shown). At this time, a predetermined level voltage vb serving as a lower limit is also set with ambient temperature characteristics.

In addition, the output voltage V; provided as a separate output is the resistance RIO
By appropriately selecting the output current l; 200mA
It is possible to obtain

Next, FIG. 8 shows another example of the charger 11 having a different configuration according to the present invention.

During copying, transistor Q is turned on, so
Normally closed terminal Nc of relay RL is OFF and secondary battery 2
Charging to is cut off. On the other hand, relay RL is O
N, from the 9e output terminal there is a resistor R as shown in Figure 5.
One output current lf passing through IG is supplied to the load.

Also, during standby, relay RL is turned on and RL is turned off, and as shown in Figure 4, resistor R1 is connected from the C output terminal.
A current l'' of 200 mA, which is the size of an eel, is supplied through the C output terminal and R11, and a charging current 1 corresponding to the battery voltage is supplied from the C output terminal to charge the secondary battery 2.

〔effect〕

As explained above, according to the present invention, since the charger is connected to the AC power supply circuit and the current is supplied to the load side via the secondary battery, it goes without saying that the AC power supply Not only is it possible to provide an image forming apparatus that can make copies even when the current is unavailable, but in the case of an AC power supply circuit, the combined current of the constant current from the charger and the discharge current from the secondary battery can be used to generate power to the load. It also has the advantage of being able to save energy since it is supplied directly to the plant.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical system configuration of an embodiment according to the present invention, FIG. 2 is a timing chart of various currents and voltages, and FIG. 3 is a current configuration during copying of the embodiment. FIG. 4 is an explanatory diagram showing the current configuration during standby, FIG. 5 is an explanatory diagram showing the current configuration during copying in a charger with a different configuration, and FIG. 6 is an explanatory diagram showing the current configuration during copying in a charger with a different configuration. Charging characteristic graph of a secondary battery, FIG. 7 is a circuit diagram of an example of a charger that implements the present invention, FIG. 8 is a circuit diagram showing another example of a charger having a different configuration, and FIG. , a circuit diagram of a serial regulator used as an example of a power supply for a conventional copying machine, FIG. 10 is a circuit diagram of a switching regulator, and FIG. 11 is a block diagram showing the electrical system configuration of a conventional copying machine. It is. 1...Charger 2...Secondary battery 3...Charging circuit Ac...AC power supply circuit l... ......Consumption tfL 1: ...Output current 1, ...Discharge current jI2 Fig. 6 Charging time M (h)

Claims (1)

[Claims] A power supply is constructed by connecting an AC power supply circuit with a charger and a secondary battery via the charging circuit, and when the AC power supply is used and the image forming operation is in progress, the current supply to the load is controlled by a constant current from the charger.
During standby, current is exclusively supplied to the load from the charger, and at the same time, the secondary battery is charged by a predetermined current from the charger. An image forming apparatus characterized in that: