JPH0767252A - Image recorder - Google Patents

Abstract

PURPOSE:To avoid such accident as firing or smoking by bringing a DC lower supply into a second mode, i.e., waiting state, when an image recorder detects an abnormality thereby blocking spread of abnormal state. CONSTITUTION:The mode (output capacity) of a DC power supply 47 is changed according to the operating state or waiting state of an image recorder. A first mode exhibiting maximum output capacity is brought about for the recording operation state and an automatic transition is made to a second mode ensuring the minimum necessary output capacity for the waiting state. When a recording paper is jammed or an abnormality is detected in a control load under the operating state of image recorder, the mode of the DC power supply 47 can switched to second mode in order to block spread of the abnormal state. Even if short circuit of cable, abnormality in control load, etc., occurs under waiting state of image recorder, such accident as firing or smoking can be avoided because the output capacity of DC power supply is low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording device such as a copying machine, a printer or a facsimile, and more particularly to a power supply device thereof.

[0002]

2. Description of the Related Art (1) In recent years, an image recording apparatus of this kind has become multifunctional, and various functions such as automatic density adjustment, automatic scaling, and automatic paper size selection function have been realized. The demographic is extremely widespread, from companies to homes.

(2) In a conventional high voltage circuit used in this type of image recording apparatus, a high voltage such as a primary DC
The following output control method is used.
That is, the first conventional example is a system in which a high voltage output as shown in FIG. 13 is directly switch-controlled, and the second conventional example is a constant current switch control as shown in FIG. It is a method. The reference numerals of the circuit components in FIGS. 13 and 14 are circuit diagrams of each embodiment described later (see FIGS.
Since the same reference numerals are used for the same (corresponding) constituent elements in 2), they will be referred to, and the duplicated description of each element will be omitted here.

[0004]

[Problems to be Solved by the Invention] (1) However,
With the trend described in the above item (1), the inside of the recording apparatus is becoming more and more complicated, and there is a strong demand for the pursuit of safety for preventing smoke and ignition when any abnormality occurs in the apparatus.

Particularly, in an image recording apparatus such as a copying machine, a plurality of DC motors, electromagnetic solenoids, electromagnetic clutches, etc. for controlling a driving unit, a large power heater for fixing a copied image on a copy sheet, etc. are used. . Therefore, when these elements become abnormal, there is a demand for a protective means for surely and safely stopping the device without causing smoke or ignition.

(2) Further, the conventional high-voltage power supply control system as described in the item (2) has the following problems. That is, for example, in the case of an electrophotographic copying machine, a high voltage, for example, a primary DC voltage changes its voltage value depending on the mode of the copying machine. For example, -600V when copying (copying) and 0V once when backing (standby)
Then set to -300V. Further, not only the voltage value but also the optimum rising characteristics required for the voltage and characteristics such as ripples are different between the copy operation and the back operation. That is, at the time of copying, the start-up characteristic is not very necessary,
Good ripple characteristics are required. This is because the ripple characteristics have a large direct effect on the image of the copy. On the other hand, the ripple characteristic is not necessary at the back,
It is necessary that the rising characteristics are good. This is because it is necessary to make the switching time as short as possible at the time of backing, but it is irrelevant to the copy image.

On the other hand, the two conventional system examples described in the preceding paragraph have the following advantages and disadvantages, respectively. That is, the first conventional example has an advantage that the time required for the output to rise is short, but has a drawback that the output ripple is large. On the other hand, the second conventional example has an advantage that the output ripple is small, but has a drawback that it takes a long time for the output to rise.

For this reason, the present invention realizes an easy and inexpensive protection means in the event of an abnormality without drastically changing the configuration of this type of image recording apparatus, and ensures and safety when an abnormality occurs in the apparatus. An object of the present invention is to provide an image recording apparatus of this type, which is provided with a protection means for stopping at I am trying.

[0009]

Therefore, in the present invention, in this type of image recording apparatus, (1) a DC power source for supplying power to a control load is in a first mode in which the DC power source is in an operating state and a standby state. In the image recording apparatus having the second mode, the DC power supply is configured to be in the second mode when the image recording apparatus detects an abnormality, and
(2) A power source that outputs a high-voltage power source and a low-voltage power source integrally, and switches the control system of at least one of the high-voltage power sources according to the recording operation / standby mode or the mode such as density adjustment. It is an object of the present invention to achieve the above-mentioned object by configuring the power supply device configured.

[0010]

According to the configuration of the present invention as described above, (1) DC depending on whether the image recording apparatus is in an operating state or a standby state.
By changing the mode (output capacity) of the power supply, in the recording operation state, it becomes the first mode in which the maximum output capacity is exerted so that the apparatus operates sufficiently, and in the standby state, the minimum required output capacity is guaranteed. The safety purpose can be met by automatically changing the mode.

That is, in each of the preferred embodiments of the present invention to be described later, when, for example, a paper jam of a recording sheet or an abnormality of a control load is detected while the apparatus is in an operating state,
It is possible to prevent the progress of the abnormal state by switching the mode of the DC power supply to the second mode. In addition, even if some abnormality such as a short circuit of the cable or an abnormality of the control load occurs when the device is in the standby state, the output capacity of the DC power source, which is the power supply source, is low, so that ignition, smoke, etc. It is possible to prevent the accident.

(2) In addition, the sequence controller of the main body of the image recording apparatus transmits to the power source control side a signal indicating which mode the apparatus is currently in, that is, the recording operation or the standby state. Therefore, the optimum control method is selected. This makes it possible to supply an output voltage having an optimum rising characteristic and ripple in each mode to the image recording apparatus.

Further, in this system, since the signal indicating whether the recording operation is in progress or the standby state is already known, it is not necessary to bother to pick up this signal. Therefore, this method is the most effective and easy to implement in a so-called combined power source in which necessary power source control is integrally performed in the image recording apparatus. In addition, these circuits are connected to the main body C
If the PU and the peripheral digital circuits such as ROM and RAM are formed on the same chip, the effect of the present invention is further enhanced.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to a plurality of embodiments: (First Embodiment) FIG. 1 is a block diagram showing the basic construction of a copying machine according to the first embodiment of the image recording apparatus according to the present invention. The figure is shown. In FIG. 1, reference numeral 45 is a control unit that controls the entire apparatus,
Reference numeral 47 is a DC power supply for supplying power to the low-voltage power supply unit 3 for supplying power to the electromagnetic solenoid, the electromagnetic clutch, the DC motor, etc. shown in 2 and the charger / developing device, etc. shown in 2a. It has a high-voltage power supply unit 4 and a CPU 40 that controls these. Reference numeral 1 denotes a mode signal sent from the control unit 45 to the DC power source 47, which indicates whether the apparatus is in a recording operation state (first mode) or a standby state (second mode). In the present embodiment, "1""When" is the operating state, "0"
Indicates the standby state.

FIG. 2 is a diagram showing the current / voltage control characteristics of the low voltage section 3 in this embodiment. In the figure, 6 is a control characteristic curve in the recording operation state (first mode), and the low voltage section 3 is It is possible to maintain the output voltage V ₁ and output a current up to I ₂ . Reference numeral 7 is a control characteristic curve in the standby state (second mode), and the low voltage portion 3 can maintain the output voltage V ₁ and output a current up to I ₁ .

FIG. 3 is a diagram showing a current / voltage control characteristic of the high voltage section 4 in the present embodiment. FIG. 3 (a) shows a control characteristic curve of a high voltage output under constant voltage control. Is the recording operation state (first mode)
With the control characteristic of, the high-voltage unit 4 can maintain the output voltage V ₂ and output a current up to I ₃ . Reference numeral 9 represents a control characteristic in the standby state (second mode), in which both the output voltage and the output current are zero.

FIG. 3B shows a control characteristic curve of high voltage output under constant current control. Reference numeral 8 in the figure shows the control characteristic in the operating state (first mode), and the high voltage section 4 shows the output current. It is possible to maintain I ₃ and output a voltage up to V ₃ . 9
Is the same as in FIG.

FIG. 4 is a schematic block diagram of the main body of the electrophotographic copying machine having the structure of this embodiment. In the figure, 13 is a main body of the copying machine, 14 is a power switch thereof, 15 is a document table on which the document 6 is placed, 16 is an image forming section, which is mainly composed of the photosensitive drum 17, and further includes a charger 18, a cleaner 19 , Erase lamp 20 and the like. Numerals 21 and 22 are developing units containing red and black toners, respectively, and are provided with respective developing rollers 21a and 22a.

Reference numeral 23 is a paper feeding unit for feeding the transfer papers SH ₁ and SH ₂ into the main body 13, and a removable cassette 24,
25 and their paper feed rollers 26 and 27. Reference numeral 28 denotes an optical system for exposing and scanning the original 6 with the exposure lamp 29 to form an image on the photosensitive drum 17, and has a lens system including a condenser lens 30.

Reference numeral 31 is an optical motor for moving the optical system 28, 22 is a fixing device having a fixing roller 33, 3
Reference numerals 4 and 35 are heaters, 36 is a paper discharge tray, and 37 is an optical stand on which the condenser lens 30 is mounted. In addition, other 3
8 is a feed roller, 39 is a charger, 40 is a separation charger, 4
Reference numeral 1 is a paper discharge roller, 42 is a main motor for driving the photosensitive drum 17, 43 and 44 are developing devices 21, 2 respectively.
2 shows the pressurizing solenoid, and S _{1 to} S ₁₅ show the optical sensors arranged in the above respective parts.

FIG. 5 is a block diagram of an electric control configuration of the copying machine, and reference numeral 45 in the drawing denotes a control unit for controlling the entire copying machine. The control unit 45 includes a CPU (not shown) and a ROM that stores control data, and controls the entire apparatus. Further, 46 is an AC power supply, and 47 is a DC power supply (hereinafter, DCP) for supplying a low voltage to the control unit 45 and the like and supplying a high voltage to the charging devices 18, 39, 40 and the developing devices 21, 22.

S is each of the sensors S ₁ to S ₁ shown in FIG.
S ₁₅ and 48 are operation units, and 49 is an AC driver that is an AC load control unit, and controls an AC load 50 such as a lamp or a heater. 51 is an optical motor 31 and a main motor 42.
A motor control unit 53 for controlling the motor is a load such as a solenoid, a clutch, and a fan.

Next, the operation of the above-mentioned copying machine will be described; in FIGS. 4 and 5, when the power switch 14 is turned on, the heaters 34 and 35 in the fixing device first generate heat and the fixing roller 33 can be fixed. Wait until a certain temperature is reached. At this time, the mode signal 1 is "0" and the DCP 47 is in the standby state. When the fixing roller 33 reaches a predetermined temperature, the controller 4
In FIG. 5, the mode signal of FIG. 1 is set to “1” and the DCP 47 is operated, and then the main motor 42 is turned on for a certain period of time to drive the photosensitive drum 17, the fixing device 32, etc. Make the temperature uniform.

Thereafter, after stopping the main motor 42, the mode signal 1 is set to "0" and the apparatus stands by in the copy ready state. When a copy command is input from the operation unit 48, a copy operation is started.

After the mode signal 1 is set to "1" by the copy command, the main motor 42 is rotated, the photosensitive drum 17 is rotated in the direction of the arrow in FIG. 4, and a high voltage is supplied from the DCP 47 to the primary charger 18. , Provides uniform charge on the photosensitive drum 17.

Next, the exposure lamp 29 is turned on, the optical motor 31 is driven, and the document 6 placed on the document table 15 is exposed and scanned in the direction of the arrow and projected onto the photosensitive drum 17. As a result, an electrostatic latent image of the original 6 is formed on the photosensitive drum 17.

This latent image is then transferred to the developing device 21 or 2
2 is developed, and the transfer charger 39 transfers the transfer paper SH ₁
Alternatively, it is transferred to SH ₂ and separated from the photosensitive drum 17 at the separation charger 40.

Next, the photosensitive drum 17 is removed by the cleaner 19.
The upper residual toner is collected and uniformly erased by the erase lamp 20, and then the copy cycle is repeated. However, the mode signal 1 is set to "0" at the end of copying.
During copying, the first developing device 21 and the second developing device 22
Either one is brought into contact with the photosensitive drum 17 according to a selection command from the operation unit 48.

Photosensitive drum 17 of these developing devices 21, 22
Pressurization (contact) and release to and from the solenoids 43 and 44. When the solenoid 43 is turned off, the developing device 21 is released from the drum 17, and when the solenoid 44 is turned on, the developing device 44 is applied to the drum 17. Is pressed. The toner sensors S ₁₅ and S ₆ are provided in the developing devices 21 and 22, respectively.
Is provided, and the developing roller 2 of each developing device 21, 22 is provided.
A developing bias voltage is applied from the DCP 47 to 1a and 22a.

The optical system 28 is reciprocally controlled by rotating the optical motor 31 in the normal / reverse direction via the motor controller 51 in accordance with a command from the controller 45. The sensor S ₁ is provided as a home position sensor of the optical system 28 and stops at this position during standby.

The sensor S ₂ is an image sensor corresponding to the position of the leading edge of the original 6, and is used for the timing of copy sequence control. Further, the optical system 28 reciprocates with a scanning length according to the cassette size and the copy magnification in response to a command from the control unit 45.

When the stop key 109 (described later in FIG. 6) is pressed during copying, the copying operation is immediately stopped, the mode signal 1 is returned to "0", and the DCP 47 is put in the standby state.

Next, the operation of the operation unit 48 will be described; FIG. 6 is an external view of the operation panel 100 of the operation unit 48. In the figure, 101 is a power switch for controlling energization to the copying machine main body 13, and 102 is an arbitrary magnification, for example, 1%.
A zoom key designated by the unit, 103 is a reduction key for instructing a fixed reduction ratio, 104 is a key for selecting the same size copy,
Reference numeral 105 is an enlargement key for instructing a fixed enlargement ratio, and 107 is a key for adjusting the copy density.

Reference numeral 108 denotes a density correction key for changing the copy density specified by the copy density adjustment key 107. In this embodiment, the exposure lamp 2 is operated by the copy density adjustment key 107.
The copy density is adjusted by controlling the lighting voltage of No. 9, and the copy density is changed by changing the developing bias with the copy density correction key 108.

A clear / stop key 109 operates as a copy stop key during execution of the copy operation. 110 is a copy key, 111 is a residual heat key, 112 is a key for returning to the standard mode, 113 is a color selection key, and this key 113 is used to switch the developing devices 21 and 22 of FIG.

Reference numeral 114 is an asterisk key used to input the length of the original 6 and a desired length after copying, and a numerical key is used to select the magnification, and the number of copies is input by this key 115.

Reference numeral 116 designates A for specifying the automatic density adjustment mode.
An E key 117 is a key for designating an automatic paper selection mode for selecting the optimum transfer paper according to the original size and the copy magnification, and 118 is an optimum magnification according to the original size and the specified transfer paper size. A key for designating the automatic magnification selection mode, 119 is a key for recalling the magnification set in the memory, 120 is a key for registering the magnification in the memory, 12
Reference numeral 1 is a warning indicator indicating that there is no toner, no control counter, and a jam occurrence state, 122 is an indicator that indicates a jam occurrence location, and 123 is an LED that indicates a specified fixed-magnification mode. It is specified.

Reference numeral 124 is an LED for displaying what kind of cassette is used for copying, and 125 is an LED for displaying the installed cassette. For example, A3 copy paper is installed in the upper stage and A4 copy paper is installed in the lower stage. When the lower row is selected, the cassette display LEDs are lit at A3 and A4, and the LED 124 is lit at A4. 12
Reference numeral 7 is an LED indicating which one of manual feed, upper tray, and lower tray is selected, and 128 is an LE that lights up when there is no paper in the cassette or when no cassette is loaded.
D, 129 is an LED for displaying the number of copies, 130 is an LED for indicating an automatic density adjustment mode, and 131 is an LE for displaying density.
D and 132 are standby display LEDs, which are lit green when copying is possible and red when copying is not possible.

Reference numeral 133 indicates L indicating the color of the designated developing device.
ED, 134 are indicators for automatic paper selection mode, 1
Reference numeral 35 is an LED indicating the automatic magnification selection mode.

Next, details of the first mode and the second mode in the present embodiment will be described; FIG. 7 is a block diagram of the internal configuration of the DC power source (DCP) 47, and 150 is a filter for removing noise. , 151 are primary side control units, and P
Performs WM (pulse width modulation) control. 152 is a transformer,
Reference numeral 153 is a low voltage control unit for PW so as to keep the output voltage constant.
M control is performed. A high voltage controller 154 is PWM-controlled so as to have a constant voltage or current. 155
Is a low voltage output current limiting circuit, and I _{2 and} I ₁ shown in FIG. 2 can be switched by setting the CPU 5 in this circuit. Reference numeral 156 is a high voltage output current limiting circuit and a high voltage output voltage limiting circuit, and the control characteristic curves 8 and 9 shown in FIG. 3 can be switched by setting the CPU 5 in this circuit.

When the mode signal 1 to the DCP 47 is "0", the CPU 5 in the DCP 47 determines that the low voltage current limiting circuit 1
55, the high-voltage current limiting circuit, and the high-voltage limiting circuit 156, and the low-voltage limiting circuit 155 sets the high-current limiting circuit and the high-voltage limiting circuit 155 so that the limit current is set to I ₁ (FIG. 2). 156 is set to the control characteristic curve 9 (FIG. 3).

When the mode signal 1 is "1",
Similarly, in the low voltage current limiting circuit 155, the setting place of the limiting current is I.
₂ (FIG. 2), the CPU 5 sets the high-voltage current limiting circuit and the high-voltage limiting circuit 156 so as to have the control characteristic curve 8 (FIG. 3).

(Second Embodiment) Next, a second embodiment will be described. In the first embodiment, switching of the first mode, which is the copy operation state, and the second mode, which is the standby state, under the control of the DC power supply 47 is performed by changing the limit current value to the current limiting circuit or the voltage limiting circuit. Although it was performed by setting the limit voltage value, by switching the maximum value of the pulse width of the PWM control of the low voltage control unit 153 and the high voltage control unit 154 shown in FIG. 7 between the first mode and the second mode described above. Also, the same operation as that of the first embodiment is possible.

Further, the same operation as in the first embodiment can be performed by switching the maximum value of the pulse width of the PWM control of the primary side control section 151 between the first mode and the second mode.

(Third Embodiment) FIG. 8 shows a third embodiment of the present invention.
As an example of the above, a circuit diagram of a power supply device of a copying machine is shown. Two
01 is an AC line input voltage, which is a diode D1,
The + output that has been rectified and smoothed through the capacitor C1 is connected to one end of the NP1 winding of the transformer T1. The other end of the NP1 winding is a switching transistor (in this embodiment, F
ET) connected to the drain of Tr1 and connected to the transistor Tr
The source of l is connected to the rectified and smoothed-output. A gate signal for driving the switching transistor Trl is generated by the drive circuit 202. Reference numeral 203 denotes a primary and secondary insulating means, which detects the low voltage output 208 and detects the drive circuit 20.
Tell 2. The transformer Tl has a plurality of secondary windings.
NSl is a high voltage winding, and NS2 is a low voltage winding. NS
The output of the second winding becomes the low voltage output 208 via the low voltage voltage filter 207. This low voltage 208 is fed back to the primary side through the primary / secondary insulating means 203 and is regulated.

On the other hand, the winding output of NS1 is the diode D
2, rectified and smoothed by the capacitor C2, each resistor R
The voltage is output as the high voltage output 204 via 1, R2 and the capacitor C5. This high-voltage output 204 is a resistor R for voltage division.
3, R4, R5, R7, the rising phase compensating capacitor C4, and the detection level adjusting resistor R6 are taken in by the first control means 205.

In the first control means 205, the detected high voltage output 204 is compared with a certain constant value (Vref), and if the high voltage output is high, the transistor Tr2 is turned on to lower the output, and conversely, if it is low, the transistor Tr2 is turned on. Control to turn off and increase output.

In the third embodiment, the first control means 20
5 shows an example in which on / off control is performed by the operational amplifier 209. The output signal of the first control means 205 drives the base of the transistor Tr2. R8 is a protection resistor for the transistor Tr2, R9 is a transistor T
It is a constant current value setting resistor for driving r2 with a constant current. R10 is a resistor for direct driving, and the resistor R10 is set to a resistance value sufficiently smaller than that of the resistor R9. Resistance R
9 drives the transistor Tr2 with a constant current, but the resistor R1
0 directly switches the high voltage output on / off.

The transistor Tr3 is a transistor for selecting constant current drive / direct drive. Second control means 2
It operates by the signal sent from 06. For example, during copying, the transistor Tr3 is off and the transistor Tr2 is driven with a constant current. Conversely, at the time of back (standby), the transistor Tr3 is on and the transistor Tr2 is
Are driven directly.

The second control means 206 is, for example, a sequence control CPU of a copying machine. Here, it is already known which mode the copier is currently in, that is, whether copying is in progress or back is in progress, so it is not necessary to bother to pick up the drive signal of the transistor Tr3 from the other. Therefore, switching between constant current drive and direct drive can be easily selected. The second control unit 206 is a control circuit different from the first control unit 205.

FIG. 9 shows an operation timing chart of this embodiment. The high-voltage voltage, for example, the primary DC voltage of the copying machine changes its voltage value depending on the mode of the copying machine as shown in FIG. For example, at the time of copying, it is set to -600V, and at the time of backing, it is set to 0V and then set to -300V.

Here, when the present invention is implemented, copy /
Simultaneously with the switching of the back, the control method is also (b)
Switch to in the figure. Actually, as shown in FIG. 7C, the switching is performed a little earlier within the range of the timing that does not affect the image. That is, since the control method is used during copying, the ripple is small. In addition, since the control system is used in the back, the rising speed is fast.
That is, the times t1, t2, and t3 in FIG. 9 are short.

(Fourth Embodiment) FIG. 10 shows a circuit diagram of a power supply device according to a fourth embodiment. The same (corresponding) components as in FIG. 8 are represented by the same reference numerals, and the duplicated description of each component is omitted (the same applies to the fifth and sixth embodiments below). In the third embodiment, the first control means 2
05 is composed of the operational amplifier 209, the PWM control circuit is used for the first control means 230 in the fourth embodiment.

231 indicates the value of the high voltage output 204 to the CPU 2
The A / D conversion circuits 233 and 234 incorporated in 32 are C
RAM and ROM for the PU 232. 235
Is a down counter for determining the on / off time when performing the PWM control, and controls the time and the time ratio by changing the initial value thereof. Reference numeral 236 denotes a PWM control calculation circuit, which outputs the output voltage captured by the A / D conversion circuit 231, and other parameters such as input voltage and output timing control (for example, sequence control during copying in the case of a copying machine). Based on this, the on / off time of the transistor Tr2 is calculated. 237 is PWM
It is a driver circuit for driving the transistor Tr2 based on the value calculated by the control calculation circuit 236.

(Fifth Embodiment) FIG. 11 shows a circuit diagram of a power supply device according to a fifth embodiment. In the third embodiment,
In contrast to the case where the potential floating portion of the capacitor C2 was switch-controlled, in the fifth embodiment, the high voltage output 2
The switch 04 is configured to be directly switch-controlled, and has a faster response than the third embodiment.

(Sixth Embodiment) FIG. 12 shows a circuit diagram of a power supply device according to a sixth embodiment. In this sixth embodiment,
A digital circuit such as a CPU, a ROM, a RAM, a counter, an analog circuit such as an A / D conversion circuit, and the control method switching means described above are integrated on one chip. In FIG. 12, reference numeral 250 is a portion formed by the same chip.

With this configuration, the second control means 206 can perform sequence control of, for example, a copying machine, a printer, etc., and at the same time, perform power supply control most suited to the state.

By integrating them on the same chip, the versatility is high and more advanced power supply control is possible.

[0059]

As described above, according to the present invention, (1) the circuit configuration is relatively easy and inexpensive, and even if an abnormality occurs in the image recording apparatus, the abnormal state is not continued as it is, By reducing the output capacity of the DC power supply, it is possible to prevent accidents such as ignition and smoke.

(2) In addition, the sequence controller of the main body of the image recording apparatus transmits to the power source control side a signal indicating which mode the apparatus is currently in, that is, the recording operation or the standby state. In response to this, the optimum control method is selected, whereby the output voltage with the optimum rising characteristics and ripples can be supplied to this device in each mode.

Further, according to the method of the present invention, since the signal indicating whether the recording operation is in progress or the standby state is already known, it is not necessary to bother to pick up this signal. For this reason, this system is the most effective and easy system to implement in a so-called composite power source in which the control of the power sources required in the image recording apparatus is performed in an integrated manner.
The effect of the present invention can be further enhanced by forming the PU and the peripheral digital circuits such as ROM and RAM on the same chip.

[Brief description of drawings]

FIG. 1 is a basic configuration block diagram of a first embodiment.

2 is a control characteristic diagram of the low-voltage power supply unit in FIG.

[Fig. 3] Fig. 1 Control characteristic diagram of high-voltage power supply unit

[Fig. 4] Schematic configuration diagram of the copying machine body

FIG. 5 is a block diagram of the electrical control configuration of FIG.

[Figure 6] External view of the operation panel

FIG. 7 is a block diagram of an internal configuration of a DC power source according to a second embodiment.

FIG. 8 is a circuit diagram of a power supply device according to a third embodiment.

9 is an operation timing chart of FIG.

FIG. 10 is a circuit diagram of a power supply device according to a fourth embodiment.

FIG. 11 is a circuit diagram of a power supply device according to a fifth embodiment.

FIG. 12 is a circuit diagram of a power supply device according to a sixth embodiment.

FIG. 13 shows an example of a conventional high voltage output control circuit.

FIG. 14 is a diagram showing another example of a conventional high-voltage output control circuit.

[Explanation of symbols]

 1 mode signal 3 low voltage part 4 high voltage part 47 DC power supply (DCP) 204 high voltage output 205,230 first control means 206 second control means 208 low voltage output 209 operational amplifier 232 CPU 236 PWM control calculation circuit 250 same chip T1 transformer Tr1 Switching transistor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display H04N 1/00 C

Claims (9)

[Claims] 1. A DC power supply for supplying power to a control load,
In an image recording apparatus having a first mode which is an operating state and a second mode which is a standby state, the DC power supply is configured to be in the second mode when the image recording apparatus detects an abnormality. An image recording device characterized by. 2. The image recording apparatus according to claim 1, wherein the output capacity of the DC power source is larger in the first mode than in the second mode. 3. A high-voltage power supply and a low-voltage power supply which are integrally output, and a control method for at least one of the high-voltage power supplies is selected according to a recording operation / standby mode or a density adjustment mode. An image recording apparatus comprising a power supply device configured to switch. 4. The image recording apparatus according to claim 3, wherein the high-voltage power supply is a primary DC power supply. 5. The secondary side output voltage is taken in order to control at least one of the secondary side output voltage of the multi-output converter transformer to a predetermined constant value, and the secondary side output is taken according to the value. In a power supply for controlling a voltage, a switch means for switch controlling the secondary side output voltage, a first control means for determining an on / off time of the switch means, and a series connection with the switch means A first current value setting means for setting a current flowing through the switch means, and a second current value setting means connected in parallel with the first current value setting means for setting a current flowing through the switch means. Current value setting means, switching means for operating either the first current value setting means or the second current value setting means, and a switching timing signal is sent to the switching means. An image recording apparatus comprising: a power supply device having a second control unit for 6. The image recording device according to claim 5, wherein the second control means of the power supply device is a first CPU for sequence control of the image recording device. 7. The image recording apparatus according to claim 5, wherein the first control means of the power supply device is on / off control configured by a comparator or the like. 8. The first control means of the power supply device outputs the secondary output voltage to a second CP via an A / D converter.
6. The image recording apparatus according to claim 5, wherein the image recording apparatus is a PWM control that takes in U, calculates an on / off time of the switch means, and outputs a drive signal of the switch means from a port of the CPU. 9. The image recording apparatus according to claim 5, wherein the power supply device is a power supply device in which the respective constituent elements are formed on the same chip.