JPH09197915A - Image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce capacitance of a smoothing condenser, to contrive cost reduction and space merit, and to reduce deflect occurrence ratio as a result of load reduction at the monentary break of a commercial power source, by widening the range of control voltage of the power source controlling IC by reducing the load when the commercial power source voltage drops. SOLUTION: An engine controller (image record controlling means) 22, detects always the voltage of the commercial power source 1 by a signal from commercial power source detecting means 31, and stops a fun motor 50 when the voltage of the commercial power source 1 falls lower than a prescribed voltage. Thus, the load can be reduced, the control voltage range of the power source controlling IC 4 can be widened, and the capacitance of the smoothing condenser 3 can be reduced. By the load reduction at the momentary break of the commercial power source 1, a stress laid on a FET 7 and the power source controlling IC 4 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can endure a momentary interruption of a commercial power source at a low cost of an image recording apparatus, particularly a page printer, a copying machine, etc., and reduce a failure occurrence rate at the moment of a momentary interruption. Image recording apparatus.

[0002]

2. Description of the Related Art Conventionally, in a small page printer or the like, an engine driving power source (12V or the like) such as a main motor, a scanner motor or a fan motor, and an engine control power source (such as an engine controller, a display panel, a sensor or a laser) ( A 2-output power supply device of 5 V or the like is used.
As this power supply device, a flyback type SW has been used in recent years.
Many power supplies are used. FIG. 4 is a circuit diagram of a conventional flyback power supply device. In FIG. 4, a commercial power supply (AC power supply) 1 is full-wave rectified by a diode bridge circuit 2 and then smoothed by a smoothing capacitor 3 to be a DC power supply. The power supply control IC 4 is usually a fixed ON time, and a frequency modulation IC that controls the OFF time is used. The power control IC 4 is activated by the start resistors 5 and 6, and after the power is activated, the FET 7 is turned ON / O.
FF control is performed. Then, when the FET 7 is ON, the main winding 27 is charged with electric power, and when the FET 7 is OFF, the electric power stored in the main winding 27 is discharged.

At this time, a voltage represented by the winding ratio between the main winding 27 and the auxiliary winding 29 is charged in the capacitor 8 via the diode 9 and serves as an auxiliary power source for the power source control IC 4 after the power source is activated. . Similarly, when the FET 7 is OFF, the voltage represented by the winding ratio of the main winding 27 and the 12V winding 28 is charged in the capacitor 20 via the diode 16 and becomes the motor power supply (12V). When the FET 7 is ON, the current stored in the capacitor 20 serves as a motor power source.
Similarly, when the FET 7 is ON, the voltage represented by the winding ratio of the main winding 27 and the 5V winding 30 is charged in the capacitor 21 via the diode 18, and becomes the control power supply (5V). When the FET 7 is off, the current stored in the capacitor 21 serves as a control power supply.

The shunt regulator 24 includes a current limiting resistor 23 and a photocoupler 12 via a current limiting resistor 23 and a photocoupler 12 so that a value obtained by dividing the voltage of the control power supply by the feedback resistors 25 and 26 and the reference voltage of the shunt regulator 24 become equal. A current is passed from the cathode to the anode. Photo coupler 1
When a current flows through the second light emitting portion, the light receiving portion is turned on, and the current flows out from the FB terminal of the power supply control IC 4. The power supply control IC 4 frequency-modulates (controls the OFF time) in accordance with this current to stabilize the power supply.

The power supply control IC 4 stabilizes the power supply by increasing the frequency (shortening the OFF time) when the load increases and decreasing the frequency (longing the OFF time) when the load is reduced. Further, when the voltage of the commercial power supply 1 is high, the frequency is lowered (the OFF time is lengthened), and when the voltage of the commercial power supply 1 is lowered, the frequency is increased (the OFF time is shortened) to stabilize the power supply.

The engine controller 22 is an image recording control means for performing all electrical control of the printer such as driving the engine of the printer, controlling the engine, and communicating with a host computer (not shown). The commercial power source detecting means (AC detecting means) 31 detects the commercial power source 1 and controls the fixing device (not shown) and the like by the engine controller 22.

[0007]

However, in the conventional power supply device, if the commercial power supply is interrupted when the load is maximum such as when printing is started, the frequency becomes extremely low. Power control IC4 and FE
There is a problem that T7 is destroyed by heat generation or the like. In order to deal with this problem, commercial power supply 1
An external circuit for stopping the oscillation of the power supply control IC 4 when the voltage becomes low is added, or a function of preventing the oscillation frequency of the power supply control IC 4 from rising above a certain frequency is added.

However, if such measures are taken,
The control range of the power supply control IC 4 becomes narrow, and even if the commercial power supply 1 is interrupted instantaneously, the capacity of the smoothing capacitor 3 must be increased in order to stabilize the output against load fluctuations. Problems such as increased cost and increased storage space occur.

The present invention has been made in view of the above points, and when the commercial power supply voltage drops, the load is reduced to widen the control voltage range of the power supply control IC and reduce the capacity of the smoothing capacitor. It is an object of the present invention to provide an image recording apparatus that can reduce the defect occurrence rate by reducing the load at the time of a momentary interruption of the commercial power source while reducing the cost and space.

[0010]

To achieve the above object, according to the present invention, in claim 1, an image recording control means for controlling the image recording apparatus and an operation of the image recording apparatus are provided. Multi-output power supply means for supplying the electric power, cooling means for cooling the image recording device, and commercial power supply detection means for detecting that the voltage of the commercial power supply input to the image recording device has dropped below a specified voltage. In the image recording apparatus having the above, the image recording control means is configured to stop the cooling means based on a signal from the commercial power source detection means.

According to another aspect of the present invention, the image recording control means for controlling the image recording apparatus, the driving means for operating the image recording apparatus, and the electric power to the driving means when the driving of the driving means is started. Power limiting means for limiting the supply,
A power limit detection unit that detects that power supply to the drive unit is limited to a constant value, a multi-output power supply unit that supplies power for operating the image recording apparatus, and a voltage of the multi-output power supply unit are switched. And a commercial power supply detecting means for detecting that the voltage of the commercial power supply input to the image recording apparatus has dropped below a specified voltage. The voltage from the multi-output power supply means is varied based on the signal from the means.

In the third aspect, the fluctuation of the voltage from the multi-output power supply means is set to 1 to 10%.

According to a fourth aspect of the present invention, image recording control means for controlling the image recording apparatus, driving means for operating the image recording apparatus, and power supply for operating the image recording apparatus are provided. Output power source means, power limiting means for limiting the power supply to the driving means at the start of driving of the driving means, and power limitation for detecting that the power supply to the driving means is limited to a constant power. Detection means, and switching means for switching the set value of the power limiting means,
In an image recording apparatus having a commercial power supply detecting means for detecting that the voltage of the commercial power supply input to the image recording apparatus has dropped to a prescribed voltage or less, the image recording control means,
The set value of the power limiting means is changed based on the signal from the commercial power source detecting means.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a circuit diagram showing a first embodiment of a power supply device for power supply of an image recording apparatus according to the present invention. In FIG. 1, components having the same functions as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. The fan motor 50 has one connection terminal of the capacitor 20 +
That is, it is connected to the side, that is, to the 12V motor power source, and the other connection terminal is connected to the switching element, for example, the collector of the transistor 51. The emitter of the transistor 50 is grounded, and the base is connected to the engine controller 22. The engine controller 22 is a fan
When the ON (fan on) signal is H (high), the transistor 51 is turned on to rotate the fan motor 50, and when the FANON (fan on) signal is L (low), the transistor 51 is turned off and the fan is turned on. Motor 50
To stop.

The engine controller 22 always detects the commercial power source 1 by the signal from the commercial power source detecting means 31, and when the voltage of the commercial power source 1 becomes lower than the specified voltage, the fanon signal is set to L to set the fan motor. Stop 50.

That is, the load (output power) is P, the stop voltage (controllable voltage) of the motor power supply at this time is V2, the capacity of the smoothing capacitor 3 on the primary side is C, the momentary interruption time of the AC power supply is T, The following formula is established when the voltage of the motor power source before the instantaneous interruption is V1.

P * T = 1/2 * C * (V1-V2) ² (1) V2 = B * P ^1/2 (B is a constant) (2) As apparent from the above equation In addition, when the load is reduced, the capacity C of the smoothing capacitor 3 on the primary side that satisfies the same instantaneous interruption time T can be considerably reduced.

In the first embodiment, the flyback method has been described, but the same applies to other than the flyback method. Further, even when the voltage of the AC power supply 1 drops below the specified voltage, the fan motor 50 may be stopped according to the state of the printer. Further, the engine controller 22 or the like may be omitted. Also, 1
Although the description has been given of the case where the two outputs of the motor power source and the control power source are simultaneously output from one transformer, they may be separately output.

In this way, the commercial power source detecting means 31
By stopping the fan motor 50 by the engine controller 22 when the voltage of the commercial power source 1 drops,
The load can be reduced and the power supply control IC4
The control voltage range of the smoothing capacitor 3
Can be reduced. Further, by reducing the load when the commercial power supply 1 is momentarily cut off, the stress applied to the FET 7 and the power supply control IC 4 can be reduced, and the defect occurrence rate can be reduced.

(Second Embodiment) FIG. 2 is a circuit diagram showing a second embodiment of a power supply device for power supply of an image recording apparatus according to the present invention. In addition, those having the same functions as those in FIG.

The transistor 62 has a collector connected to a connection point between the feedback resistors 25 and 26 for dividing the voltage of the control power supply, an emitter grounded through a hood back resistor 61, and a base connected to a control terminal of the engine controller 22. It is connected to the. Shunt regulator 24
Compares the voltage divided by the feedback resistors 25, 26, 61 with the built-in reference voltage when the transistor 62 is on. With transistor 62 off,
Since the voltage of the control power supply divided by the feedback resistors 25 and 26 becomes higher than the built-in reference voltage and the output is controlled to be lowered, the voltage value of the control power supply can be lowered. At the same time, the voltage of the motor power source output from the same transformer also decreases.

The motor driver 63 has an input terminal connected to the + side (12V motor power source) of the capacitor 20, and R
The DY terminal is connected to the engine controller 22. The main motor 64 is a main motor for driving the engine, and one connection terminal is a motor driver 63.
And the other terminal is grounded via the current limiting resistor 65 and is connected to the CS terminal of the motor driver 63. The motor driver 63 uses a rotation detecting means (not shown) such as a hall element mounted in the main motor 64 so that the actual rotation speed of the main motor 64 becomes equal to the target rotation speed. It is for turning on and off the power supply for control. Current limiting resistor 6
No. 5 stops turning on the motor driver 63 when a current of a certain amount or more flows in the main motor 64 when the torque of the main motor 64 is large at the start of printing, and heats the motor driver 63 and the main motor 64. This is to prevent destruction from the. Main motor 6
In No. 4, the current consumption decreases when the specified rotation speed is reached, and the motor driver 63 outputs the RDY signal to the engine controller 22 when the main motor 64 reaches the specified rotation speed.

The engine controller 22 constantly detects the commercial power source 1 from the signal from the commercial power source detecting means 31, and the signal from the power source detecting means 31 for use is detected when the main motor 64 is started up (started). When input, the transistor 62 is turned off to lower the voltage value of the control power supply.
Even if the voltage applied to the main motor 64 decreases, the current supplied to the main motor 64 is controlled to be constant by the current limiting resistor 65, so the power supplied to the main motor 64 decreases. Further, when the voltage value of the control power supply decreases, the electric power consumed by the engine controller 22 or the like also decreases, so that the total load decreases. When the load is reduced, as is clear from the equation shown in the first embodiment, the capacity of the smoothing capacitor 3 on the primary side that satisfies the same instantaneous interruption time can be considerably reduced. The range of the voltage to be lowered by the control power supply is set to a range of 1 to 10% so as not to fall below the operation guarantee voltage of the engine controller 22, so that the engine controller 22 maintains the normal operation even after the voltage drops. be able to.

In the second embodiment, the flyback method has been described, but the same applies to other than the flyback method. In the second embodiment, the main motor 64 is started up, but the scanner motor or the like may be started up. Further, the voltage drop except when the main motor is started does not reduce the load because the output of the main motor 64 and the like is kept constant, but it is effective because the load of the motor driver 63 and the engine controller 22 and the like decreases.

In this way, the commercial power source detecting means 31
When the voltage of the commercial power source 1 drops, the engine controller 22 changes the feedback constant of the control power source,
By lowering the voltage value, the load can be reduced,
Along with this, the control voltage range of the power supply control IC 4 can be widened, and the capacity of the smoothing capacitor 3 can be reduced. Further, by reducing the load when the commercial power supply 1 is momentarily cut off, the stress applied to the FET 7 and the power supply control IC 4 can be reduced, and the defect occurrence rate can be reduced.

(Third Embodiment) FIG. 3 is a circuit diagram showing a third embodiment of a power supply unit for supplying power to an image recording apparatus according to the present invention. Note that those having the same functions as those in FIG. Transistor 72
Has a collector connected to the connection point between the other connection terminal of the main motor 64 and the current limiting resistor 65, an emitter grounded via the resistor 71, and a base connected to the engine controller 22. The resistor 71 is a current limiting resistor 65.
It is connected in parallel with, and acts to change the current limit value of the main motor 64.

The engine controller 22 always detects the voltage of the commercial power source 1 by the signal from the commercial power source detecting means 31, and when the signal is input from the commercial power source detecting means 31 when the main motor 64 is started, The transistor 72 is turned off to limit and reduce the maximum current flowing through the main motor 64. When the maximum current is limited and goes low,
Since the voltage applied to the main motor 64 is constant, the electric power supplied to the main motor 64 is reduced and the total load is reduced. When the load is reduced, the capacity of the smoothing capacitor 3 on the primary side, which satisfies the same instantaneous interruption time, can be considerably reduced, as is clear from the equation shown in the first embodiment. It goes without saying that the current value for limiting the current of the main motor 64 is set to be larger than the current value required for the main motor 64 to at least rise (start).

In the third embodiment, the flyback method has been described, but the same applies to other than the flyback method. In addition, in the third embodiment, the main motor 64 is started up, but it may be started up when the scanner motor or the like is started up.

In this way, the commercial power source detecting means 31
When the voltage of the commercial power source 1 drops, the load can be reduced by changing the limit value of the maximum current flowing to the main motor 64, the scanner motor, etc. by the engine controller 22, and accordingly, the control of the power source control IC 4 can be performed. The voltage range can be widened, and the capacity of the smoothing capacitor 3 can be reduced. Further, by reducing the load when the commercial power source is momentarily cut off, the stress applied to the FET 7 and the power source control IC 4 can be reduced, and the defect occurrence rate can be reduced.

[0031]

As described above, according to the image recording apparatus of the first aspect, when the commercial power supply detecting means reduces the voltage of the commercial power supply, the image recording control means stops the fan motor. The load can be reduced, the control voltage range of the power supply control IC can be widened accordingly, and the capacity of the smoothing capacitor can be reduced. In addition, due to the reduction of the load during a momentary interruption of commercial power, F
The stress applied to the ET and the power supply control IC can be reduced, and the defect occurrence rate can be reduced.

According to the image recording apparatus of the second aspect, when the commercial power source detecting means reduces the voltage of the commercial power source, the image recording control means changes the feedback constant of the control power source to lower the voltage value. Thus, the load can be reduced, the control voltage range of the power supply control IC can be widened accordingly, and the capacity of the smoothing capacitor can be reduced. Further, by reducing the load when the commercial power source is instantaneously cut off, the stress applied to the FET and the power source control IC can be reduced, and the defect occurrence rate can be reduced.

According to the image recording apparatus of claim 4, when the commercial power supply voltage is lowered by the commercial power supply detecting means, the limit value of the maximum current flowing through the main motor, the scanner motor, etc. is changed by the image recording control means. As a result, the load can be reduced, the control voltage range of the power supply control IC can be widened accordingly, and the capacity of the smoothing capacitor can be reduced. Further, by reducing the load when the commercial power source is instantaneously cut off, the stress applied to the FET and the power source control IC can be reduced, and the defect occurrence rate can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a power supply device for supplying power to an image recording apparatus according to the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of a power supply device for power supply of an image recording apparatus according to the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of a power supply device for supplying power to an image recording apparatus according to the present invention.

FIG. 4 is a circuit diagram of a conventional flyback power supply device.

[Explanation of symbols]

 1 Commercial Power Supply 2 Diode Bridge Circuit 3 Smoothing Capacitor 4 Power Supply Control IC 7 FETs 9, 16, 18 Diodes 8, 20, 21 Capacitor 12 Photocoupler 22 Engine Controller 24 Shunt Regulator 27 Main Winding 28 12V Winding 29 Auxiliary Winding Wire 30 5V winding 31 Commercial power source detecting means 50 Fan motor 51, 62, 72 Transistor 64 Main motor

Claims (4)

[Claims] 1. An image recording control means for controlling the image recording apparatus, a multi-output power supply means for supplying electric power for operating the image recording apparatus, and a cooling means for cooling the image recording apparatus. And an image recording apparatus having a commercial power source detecting means for detecting that the voltage of the commercial power source input to the image recording apparatus has dropped to a prescribed voltage or less, wherein the image recording control means is An image recording apparatus, wherein the cooling means is stopped based on a signal. 2. An image recording control unit for controlling the image recording apparatus, a driving unit for operating the image recording apparatus, and a power supply to the driving unit when starting the driving of the driving unit. For limiting the power supply to the driving means, a multi-output power supply means for supplying power for operating the image recording apparatus, and In the image recording apparatus, there is provided switching means for switching the voltage of the multi-output power source means, and commercial power supply detecting means for detecting that the voltage of the commercial power supply input to the image recording apparatus has dropped below a specified voltage. An image recording apparatus, wherein the control means varies the voltage from the multi-output power supply means based on a signal from the commercial power supply detection means. 3. The image recording apparatus according to claim 2, wherein the fluctuation of the voltage from the multi-output power supply means is 1 to 10%. 4. An image recording control means for controlling the image recording apparatus, a driving means for operating the image recording apparatus, and a multi-output power supply means for supplying electric power for operating the image recording apparatus. A power limiting means for limiting the power supply to the driving means when the driving means starts driving, and a power limit detecting means for detecting that the power supply to the driving means is limited to a constant power. An image recording apparatus having switching means for switching the set value of the power limiting means, and commercial power source detection means for detecting that the voltage of the commercial power source input to the image recording apparatus has dropped below a specified voltage, An image recording apparatus, wherein the image recording control means changes a set value of the power limiting means based on a signal from the commercial power source detecting means.