JPH10106763A - Power supply device for incandescent lamp, incandescent lamp lighting device, reader and oa equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a change in the light quantity of an incandescent lamp, and prevent the deterioration of an image quality by reducing a feedback quantity by the action of a feedback quantity correcting means for a specific time after a start time passes. SOLUTION: Difference voltage between output voltage of a voltage divider 8C and reference electric potential is set as a feedback quantity, and an on-duty time of a switching means 3 is changed according to the feedback quantity by referring to the formation of a control signal of a control means 10. A feedback quantity correcting means 9 is connected to a reference voltage source 8d, and a time constant circuit 9a is composed of a resistor 9a1 and a capacitor 9a2 connected to a DC power supply through a read start switch 11. Preferably, a time constant of the time constant circuit 9a is set in a temperature saturation time of a light unemitting part of an incandescent lamp 7. After lighting of the incandescent lamp 7 is started, in the temperature saturation time of the light unemitting, since feedback voltage is reduced and the feedback quantity is reduced, a quantity of light of the incandescent lamp 7 is kept constant, and the deterioration of an image quality can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for an incandescent lamp, an incandescent lamp lighting device using the same, a reading device and an O.
Related to the A device.

[0002]

2. Description of the Related Art An O such as a copying machine and an image scanner is used.
A device using an incandescent light bulb as a light source for reading in the A device is known. This incandescent light bulb has a light-emitting portion long enough to cover the width of the base paper to be read, and the light-emitting portion is divided into several segments for uniform illuminance at short distances, and furthermore, there is a gap between each segment. They are connected in series by a non-light emitting part.

The light emitting portion is made of a refractory metal such as tungsten, for example, a double coil filament, and the non-light emitting portion is made of a refractory metal such as tungsten in a single coil, for example, compared to a coil filament of a metal such as molybdenum. A thick wire is inserted. As an incandescent lamp having such a configuration, a bar-shaped halogen lamp is used relatively frequently.

By the way, this kind of incandescent lamp is lit by using a power supply device having a constant voltage characteristic in order to keep the light quantity constant even if the power supply voltage fluctuates.

FIG. 6 is a circuit diagram showing a conventional power supply device for an incandescent lamp.

In the figure, 61 is an AC power supply, 62 is a rectified and smoothed DC power supply, 63 is a switching means, 64 is a flywheel diode, 65 is a flyback type inductor, 66 is a smoothing capacitor, 67 is an incandescent lamp, 68
Is a feedback means, and 69 is a control means.

The incandescent lamp 67 is a halogen lamp for reading in which a filament composed of a light emitting portion divided into a plurality of segments and a non-light emitting portion connecting the segments in series in an elongated bulb is sealed.

The feedback means 68 includes a feedback winding 68a electromagnetically coupled to the inductor 65, a diode 68b for rectifying the output voltage of the feedback winding 68a, a voltage divider 68c for dividing the rectified voltage, and a read start switch 70 in series. And a reference voltage source 68d connected to a DC power supply (not shown). A difference voltage between the reference voltage and the output voltage of the voltage divider is taken out by a comparator 69a of the control means 69, and a feedback amount for controlling the control means 69 is provided. Become.

The control means 69 generates a control signal for the switching means 63, and changes the on-duty of the control signal in a negative feedback manner according to the feedback amount.

The switching means 63 switches the direct current at a high frequency, stores the electromagnetic energy in the inductor 65 when it is turned on, and emits the stored electromagnetic energy via the flywheel diode 64 when it is turned off.
The voltage smoothed by the smoothing capacitor 66 is applied to the halogen bulb 67 to light it.

[0011]

The non-light-emitting portion of the halogen bulb needs to have a resistance value as small as possible so as not to emit light even when a rated lamp current flows. The thermal inertia is large because of the use. For this reason, the time from the start of lighting of the incandescent lamp to the stabilization of the temperature of the non-light emitting portion is long. Tungsten and molybdenum, like ordinary metals, have a positive resistance to temperature, so when lit under a constant voltage, the temperature gradually increases due to the large thermal inertia of the non-light-emitting part. As the resistance increases, the resistance value increases, and the lamp current gradually decreases. For this reason,
Until the temperature of the non-light emitting portion is stabilized, the light amount of the incandescent light bulb gradually decreases, and when it becomes stable, the light amount becomes constant thereafter.

FIG. 2 is a graph showing a change in the amount of light with respect to time when the incandescent lamp is turned on by the incandescent lamp power supply device.

In the figure, the horizontal axis represents time in seconds, and the vertical axis represents the amount of lamp light as a relative value. On the horizontal axis, period A indicates the start-up time of the light emitting unit, B indicates the temperature saturation time of the non-light emitting unit, and C indicates the stable period of the incandescent lamp. In a 100 W to 300 W class incandescent lamp generally used in OA equipment such as a copying machine and an image scanner, the startup rise time of the light emitting unit is 20 minutes.
0 mS to 500 mS, and the temperature saturation time of the non-light emitting portion is about 1 minute. Curve b shows the change in the amount of light in the case of the prior art shown in FIG. 6, and it can be seen that the amount of light gradually decreases within the temperature saturation time of the non-light emitting portion.

Therefore, when the OA device is used within the temperature saturation time of the non-light emitting portion, the amount of light changes during reading one document, and the image density changes to degrade the image quality. There is.

The present invention provides a power supply device for an incandescent lamp, which prevents deterioration in image quality by eliminating a change in the amount of light of the incandescent lamp during the temperature saturation time of the non-light emitting portion, an incandescent lamp lighting device and a reading device using the same. And OA equipment.

[0016]

According to the first aspect of the present invention, there is provided a power supply device for an incandescent lamp, comprising: switching means for switching DC at a high frequency; means for smoothing the switched voltage; and loading the smoothed voltage into a load. Output means for detecting the load voltage or load current and outputting a feedback voltage; control means for generating a control signal for the switching means in accordance with the feedback voltage; and a predetermined time after the start-up time has elapsed. And feedback amount correcting means that operates to reduce the feedback amount for controlling the control means from the actual detection value.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

As an incandescent lamp, a halogen lamp is generally used frequently, and thus a halogen lamp may be used, but the present invention is not limited to this. For example, an incandescent lamp or the like in which xenon gas is sealed may be used. Further, a small light bulb may be configured for each segment of the light emitting unit, and the small light bulbs may be connected to each other by a non-light emitting unit, or a light bulb in which this connected body is mounted in an elongated bulb. In this case, the valve may be sealed and an inert gas may be sealed therein, or may not be sealed.

The direct current may be any type such as a storage battery or other direct current power source and a direct current obtained by rectifying an alternating current.

The high frequency may be 1 KHz or more, and is usually in a frequency range of 20 KHz or more.

The switching means is for switching a direct current, and is preferably a semiconductor switching element such as a transistor. Although the circuit configuration of the switching means is not particularly limited, for example, a forward type or an on-on type using a flywheel diode connected in parallel to the load, a diode inserted in series with the load And various known circuit systems such as a flyback system or an on-off system.

The smoothing means smoothes the high-frequency chopping waveform by means of the switching means to obtain a flat or slightly pulsating DC.

The feedback means detects a load voltage or load current and obtains a feedback voltage in order to energize the load with constant power. As long as a feedback voltage proportional to the load voltage or the load current can be output, detection may be performed at any circuit position, and any circuit configuration may be used. For example, in order to detect a load voltage, a flyback type inductor may be inserted in series with the load in addition to detecting the terminal voltage of the load, and a feedback winding may be electromagnetically coupled to the inductor. To detect the load current, a current transformer may be inserted in series with the load.

The control means controls the switching of the switching means in order to operate the load at constant power irrespective of the fluctuation of the power supply voltage. When an incandescent lamp is used as a load, since the resistance value of the load is constant, constant power can be obtained by keeping the terminal voltage of the load constant or the load current constant. For this reason, by controlling the on-duty of switching of the switching means in a non-feedback manner in accordance with the amount of feedback from the feedback means, it is possible to apply a desired characteristic to the load and to energize the load.

The purpose of the feedback amount correcting means is to correct a decrease in the amount of light of the incandescent lamp due to a rise in the resistance value of the non-light emitting portion of the incandescent lamp during the temperature saturation time. This is realized by reducing the amount of feedback input to. Therefore, the configuration of the feedback amount correction means may be any configuration as long as it performs the above-described operation.

Here, the predetermined time is preferably a time covering the temperature saturation time of the non-light emitting portion of the incandescent lamp, but a slight time lag is allowed.

Since the amount of light emitted from the light-emitting portion is small and the amount of light increases rapidly during the start-up rising time, it is desirable to substantially reduce this time. This is possible by adding functions to the control means.

Thus, in the present invention, the feedback amount from the load is reduced by the feedback amount correcting means for a predetermined time after the start-up time, so that the resistance value of the non-light emitting portion increases even during the predetermined time. The light amount of the incandescent lamp can be maintained constant by compensating for the decrease in the light amount accompanying the light emission.

The present invention is also effective for improving the initial drift characteristics of a power supply for an incandescent lamp.

The power supply device for an incandescent lamp according to the second aspect of the present invention
2. The power supply device for an incandescent lamp according to claim 1, wherein the feedback unit includes a detection unit that detects a load voltage or a current, a voltage division unit that divides an output of the detection unit, and a reference voltage source. It is characterized in that the control means is controlled by using a difference voltage of the reference voltage as a feedback voltage.

According to the present invention, the configuration of the feedback means is defined, and the feedback amount for controlling the control means is obtained by the difference voltage between the output voltage obtained from the detection means via the voltage divider and the reference voltage.

The reference voltage source may have any configuration as long as a reference voltage can be obtained.

The power supply unit for an incandescent light bulb according to the third aspect of the present invention comprises:
The power supply device for an incandescent light bulb according to claim 2, wherein the feedback amount correcting means increases the reference voltage of the reference voltage source for a predetermined time.

According to the present invention, the reference voltage is increased to reduce the feedback amount for a predetermined time. In other words, if the output voltage of the voltage divider does not change, the difference voltage, that is, the feedback voltage decreases and the output voltage increases as the reference voltage increases. Any configuration may be used for increasing the reference voltage.

According to a fourth aspect of the present invention, there is provided a power supply for an incandescent lamp.
The power supply device for an incandescent lamp according to claim 2, wherein the feedback amount correcting means reduces the output of the voltage dividing means for a predetermined time.

The present invention reduces the output voltage of the voltage divider to reduce the amount of feedback for a predetermined time. That is, if the output of the voltage divider decreases if the reference voltage remains unchanged, the difference voltage, ie, the feedback voltage, will decrease. As a means for reducing the output of the voltage divider, for example, a non-linear resistor may be used in combination, and the resistance may be controlled for a predetermined time by a time constant by the resistor itself or external temperature control. it can.

According to a fifth aspect of the present invention, there is provided a power supply device for an incandescent lamp.
The power supply device for an incandescent lamp according to claim 3 or 4,
The feedback amount correction means includes a time constant circuit.

According to the present invention, the feedback amount correcting means is constituted by using a time constant circuit. If the time constant of the time constant circuit is set to a predetermined time, the correction can be realized with a simple structure. That is, if correction is performed on the side of the reference voltage source,
The reference voltage may be influenced by the terminal voltage of the capacitor of the time constant circuit. If the correction is performed on the voltage divider side, the output voltage of the voltage divider may be affected by the terminal voltage of the resistor of the time constant circuit.

The power supply device for an incandescent lamp according to the invention of claim 6 is
The incandescent lamp power supply device according to any one of claims 1 to 5, wherein the startup rising time is substantially the temperature saturation time of the light emitting portion of the incandescent lamp, and the predetermined time is substantially the temperature saturation of the non-light emitting portion of the incandescent light bulb. It is characterized by being set to time.

The present invention confirms that the predetermined time is the temperature saturation time of the non-light emitting portion of the incandescent lamp. Since the temperature saturation time differs depending on the structure of the incandescent lamp to be used, it is necessary to set a predetermined time for each incandescent lamp.

According to a seventh aspect of the present invention, there is provided a power supply device for an incandescent lamp.
The power supply device for an incandescent lamp according to any one of claims 1 to 6, wherein the feedback means is configured to adjust a feedback voltage.

According to the present invention, the output of the power supply device can be adjusted by configuring the feedback voltage to be adjustable. Therefore, the output can be adjusted at the time of assembling the power supply device, or can be adapted to different loads.

The power supply device for an incandescent lamp according to claim 8 is the power supply device for an incandescent lamp according to any one of claims 1 to 7, further comprising a DC power supply for rectifying AC.

Since the present invention has a rectified DC power supply, it can be used by connecting to an AC power supply. Needless to say, a smoothing means can be added as necessary.

According to a ninth aspect of the present invention, there is provided an incandescent lamp lighting device comprising: the power supply device for an incandescent lamp according to any one of the first to eighth aspects; And an incandescent lamp supplied with power from the output means of the incandescent lamp power supply device.

The present invention is an incandescent lamp lighting device having the functions and features of claims 1 to 8.

According to a tenth aspect of the present invention, there is provided a reading device comprising: a reading device main body; and the incandescent lamp lighting device according to the ninth aspect, which is provided in the reading device main body.

The present invention is a reading apparatus having the functions and features of claims 1 to 8. This reading apparatus can be used by incorporating it into an OA device such as a copying machine or an image scanner, or can be used alone if necessary.

An OA device according to an eleventh aspect of the present invention is the OA device main body; an incandescent lamp provided in a reading mechanism in the OA device main body; and an output terminal connected to the incandescent lamp. And a power supply device for an incandescent lamp according to one of the preceding claims.

The present invention is an OA apparatus having the functions and features of the first to eighth aspects.

[0051]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a first embodiment of a power supply device for an incandescent lamp and an incandescent lamp lighting device according to the present invention.

In the figure, 1 is an AC power supply, 2 is a rectified and smoothed DC power supply, 3 is a switching means, 4 is a flywheel diode, 5 is a flyback type inductor, 6
Is a smoothing capacitor, 7 is an incandescent lamp, 8 is feedback means, 9 is feedback amount correction means, and 10 is control means.

As the AC power supply 1, a commercial power supply of, for example, 100 V can be used.

The rectifying / smoothing DC power supply 2 rectifies and smoothes the AC to obtain a flat DC, and supplies the flat DC to the switching means 3.

The switching means 3 uses a transistor. Then, when the switching means 3 is turned on, electromagnetic energy is accumulated in the inductor 5 via the smoothing capacitor 6, and when the switching means 3 is turned off,
The electromagnetic energy of the inductor 5 is smoothed through the flywheel diode 4 together with the discharge of the accumulated charge of the smoothing capacitor 6 and supplied to the incandescent lamp 7 of the load.
The incandescent lamp 7 lights up.

The feedback means 8 includes a feedback winding 8a magnetically coupled to the inductor 5, a diode 8b for rectifying the induced voltage of the feedback winding 8a, and a voltage divider 8c for dividing the DC voltage rectified by the diode 8b. And a smoothing capacitor 8e connected to a DC power supply. The difference between the output voltage of the voltage divider 8c and the reference potential is referred to as a feedback amount in forming a control signal of the control means 9. Since the inductor 5 is a flyback type, the terminal voltage of the inductor 5 is proportional to the terminal voltage of the incandescent lamp 7, so that a voltage proportional to the load voltage can be extracted from the feedback winding 8a.

The feedback amount correcting means 9 mainly includes a time constant circuit, and is connected to the reference voltage source 8d. That is, the feedback amount correction means 9 includes a time constant circuit 9a including a resistor 9a1 and a capacitor 9a2 connected to a DC power supply (not shown) via a read start switch 11, and a capacitor 9a.
2 comprises a discharge resistor 9b connected between both ends of the capacitor 2 and a diode 9c for preventing a wraparound which is interposed when the both ends of the capacitor 9a2 are arranged in parallel with the reference voltage source 8d. The time constant of the time constant circuit 9a is set to the temperature saturation time of the non-light emitting portion of the incandescent lamp 7.

The control means 10 generates a control signal for the switching means 3 and changes the on-duty of the switching means 3 according to the feedback amount. In order to extract the difference voltage, ie, the feedback voltage, the control means 10 includes the comparator 1
0a, and the output of the voltage divider 8c of the feedback means 8 and the reference potential are input to the comparator 10a. And the comparator 1
0a outputs a difference voltage, that is, a feedback voltage, and controls generation of a control signal.

In this embodiment, when the reading start switch 11 is turned on and a DC power supply is connected to the switching means 3 at the same time, the switching means 3 and the feedback means operate as described above to operate the incandescent lamp 7. Is started, but within the temperature saturation time of the non-light-emitting portion, the terminal voltage of the capacitor 9a2 of the time constant circuit 9a gradually increases due to the fact that charging is in progress. Accordingly, the reference voltage source 8d
The reference voltage obtained at the same time gradually increases. As a result, the difference voltage, that is, the feedback voltage, which is the output of the comparator 10a, decreases with time to reduce the amount of feedback, and as a result, the output voltage of the power supply gradually increases. In this manner, the increase in the output voltage of the power supply unit due to the increase in the resistance value of the non-light emitting portion cancels out the increase in the voltage by the feedback amount correcting means 9, so that the voltage and therefore the light quantity of the incandescent lamp are kept constant. Will be maintained. For this reason, even if reading is performed during the temperature saturation time of the non-light emitting portion, the image quality does not deteriorate.

FIG. 2 is a graph showing a change in the amount of light with respect to time when the incandescent lamp is turned on.

Other than the description related to the curve A in FIG. 2 has already been described in the prior art, the description here is omitted.

A curve A shows the light amount in the case of the present embodiment. That is, according to the present embodiment, the light amount of the incandescent lamp 7 is constant even within the temperature saturation time of the non-light emitting portion as shown by the curve A.

FIG. 3 is a circuit diagram showing a power supply device for an incandescent lamp and an incandescent lamp lighting device according to a second embodiment of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

This embodiment differs from the first embodiment in the structure of the feedback amount correcting means 9 '. That is, the feedback amount correcting means 9 'is connected to the voltage divider 8c, and corrects the feedback amount by reducing the output of the voltage divider 8c from an actual detection value and correcting the output. Then, the feedback amount correcting means 9 '
It consists of a non-linear resistor such as a thermistor or a time constant circuit. In the case of a time constant circuit, connect the resistor.

Thus, in the present embodiment, the feedback voltage from the feedback winding 8a is reduced by the feedback amount correction means 9 ', so that the feedback amount is reduced and the light amount of the incandescent lamp is kept constant. .

FIG. 4 is a conceptual diagram showing an embodiment of the reading apparatus of the present invention.

In the figure, 7 is an incandescent lamp, 12 is a light receiving means, and 13 is a reflecting mirror of the incandescent lamp 7. The light receiving means 12 is illuminated at a short distance by an incandescent light bulb, receives light reflected on the base paper surface, and generates a read signal. The optical axis of the reflecting mirror 13 is inclined so that the light reflected on the original paper surface is directed to the light receiving means 12. A signal processing device 14 processes the read signal. Reference numeral 15 denotes a base paper mounting surface, which is made of, for example, transparent glass. Reference numeral 16 denotes a case for storing each of the above components.
Incandescent lamp 7 and power supply for incandescent lamp (not shown)
The other components except for constitute the reading device main body.

FIG. 5 is a conceptual diagram showing a copying machine as one embodiment of the OA equipment of the present invention.

In the figure, 17 is a reading device, 18 is an image forming device, 19 is a fixing device, 20 is a paper feed tray, and 21 is a case.

In this copying machine, the image of the base paper is optically read by the reading device 17 to form an image signal. An inverted electrostatic latent image is formed on the photosensitive drum of the image forming apparatus 18 by the image signal. Next, toner is attached to the reversal electrostatic latent image to form a reversal visual image, and the reversal visual image is transferred to plain paper taken out of the paper feed tray 20 to form a fixing member on which an image is formed. The object to be fixed then proceeds to the fixing device 19 and is heated by a fixing heater in the fixing device. At this time, the toner is fused to the plain paper to obtain a fixed image. The fixing member is taken out of the case 21 by a guide roller after fixing.

[0073]

According to the first to eighth aspects of the present invention, the feedback amount is reduced by the operation of the feedback amount correcting means for a predetermined time after the elapse of the startup rising time, so that the incandescent lamp can be used during the temperature saturation time. It is possible to provide a power supply device for an incandescent light bulb in which a change in the amount of light of the incandescent light bulb is prevented and a deterioration in image quality is prevented.

According to the second aspect of the present invention, the difference between the reference voltage and the divided voltage of the load voltage or the load current detection voltage is defined as the feedback amount by defining the configuration of the feedback means. It is possible to provide a power supply device for an incandescent light bulb in which the amount can be easily corrected.

According to the invention of claim 3, it is possible to provide a power supply device for an incandescent lamp in which the reference voltage is corrected by the correction means.

According to the invention of claim 4, it is possible to provide a power supply device for an incandescent lamp in which the output of the voltage dividing means is corrected by the correcting means.

According to the fifth aspect of the present invention, it is possible to provide a power supply device for an incandescent lamp in which the configuration of the correction means is simplified by using the time constant circuit as a component of the correction means.

According to the invention of claim 6, in addition, the startup rising time is the temperature saturation time of the light emitting portion of the incandescent lamp, and the predetermined time is set to the temperature saturation time of the non-light emitting portion. It is possible to provide an incandescent lamp power supply device in which the light amount is constant after a predetermined time.

According to the seventh aspect of the present invention, it is possible to provide a power supply device for an incandescent lamp which can adjust a feedback voltage to facilitate assembly adjustment and can cope with different incandescent lamps.

According to the eighth aspect of the present invention, it is possible to provide a power supply device for an incandescent lamp having a DC power supply.
According to the ninth aspect, it is possible to provide an incandescent lamp lighting device having the effects of the first to eighth aspects.

According to the tenth aspect, it is possible to provide a reading apparatus having the effects of the first to eighth aspects.

According to the eleventh aspect, it is possible to provide an OA device having the effects of the first to eighth aspects.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a power supply device for an incandescent lamp and an incandescent lamp lighting device of the present invention.

FIG. 2 is a graph showing a change in light amount with respect to time when an incandescent lamp is turned on.

FIG. 3 is a circuit diagram showing a power supply device for an incandescent lamp and an incandescent lamp lighting device according to a second embodiment of the present invention;

FIG. 4 is a conceptual diagram showing an embodiment of the reading device of the present invention.

FIG. 5 is a conceptual diagram showing a copying machine as an embodiment of an OA device of the present invention.

FIG. 6 is a circuit diagram of a conventional power supply device for an incandescent lamp.

[Explanation of symbols]

 2 rectifying / smoothing rectifying means 3 switching means 4 flywheel diode 5 inductor 6 smoothing capacitor 7 incandescent lamp 8 feedback means 9 feedback amount correcting means

Claims (11)

[Claims] A switching means for switching a direct current at a high frequency; a smoothing means for smoothing a switched voltage; an output means for outputting the smoothed voltage to a load; and detecting a load voltage or a load current. Feedback means for outputting a feedback voltage according to the feedback voltage; control means for generating a control signal for the switching means in accordance with the feedback voltage; and a feedback amount for controlling the control means at a predetermined time after the elapse of the start-up rise time. And a feedback amount correcting means operable to cause the electric power to be supplied to the incandescent lamp. The feedback means includes a detection means for detecting a load voltage or a current, a voltage division means for dividing an output of the detection means, and a reference voltage source, and feeds back a difference voltage between the output voltage of the voltage division means and the reference voltage. The power supply device for an incandescent lamp according to claim 1, wherein the control means controls the voltage as the voltage. 3. The power supply device for an incandescent lamp according to claim 2, wherein the feedback amount correcting means increases the reference voltage of the reference voltage source for a predetermined time. 4. The power supply device for an incandescent lamp according to claim 2, wherein the feedback amount correcting means decreases the output of the voltage dividing means for a predetermined time. 5. The power supply device for an incandescent lamp according to claim 3, wherein the feedback amount correction means includes a time constant circuit. 6. A start-up time is substantially equal to a temperature saturation time of a light emitting portion of the incandescent lamp, and the predetermined time is set to substantially a temperature saturation time of a non-light emitting portion of the incandescent lamp. 6. The power supply device for an incandescent lamp according to any one of 1 to 5. 7. The incandescent lamp power supply device according to claim 1, wherein the feedback means is configured to adjust a feedback voltage. 8. The power supply for an incandescent lamp according to claim 1, further comprising a DC power supply for rectifying an AC. 9. A power supply for an incandescent lamp according to any one of claims 1 to 8, further comprising: a light-emitting portion divided into a plurality of segments; and a non-light-emitting portion connecting in series between adjacent segments. An incandescent light bulb supplied from an output means of a power supply device for a light bulb. 10. A reading device comprising: a reading device main body; and the incandescent bulb lighting device according to claim 9 disposed in the reading device main body. 11. The incandescent lamp power supply device according to claim 1, wherein an OA device main body; an incandescent lamp disposed in a reading mechanism in the OA device main body; and an output end connected to the incandescent lamp. OA equipment characterized by comprising: