JP2009136100A - Power supply device, electronic apparatus, discharge lamp lighting device, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To notify the replacement time of an electrolytic capacitor through simple circuitry. <P>SOLUTION: A power supply device 100 includes: a rectifying circuit 110 for rectifying an alternative current voltage AC supplied from outside to output a direct current voltage DC; an electrolytic capacitor 112 for retaining the direct current voltage DC; and a voltage monitoring section 114 which monitors the elapsed time from when the alternative current AC is turned off until when the voltage value of the direct current voltage DC reaches a prescribed voltage value, and which outputs a notification signal IS notifying the replacement time of an electrolytic capacitor 112 when the elapsed time becomes less than a prescribed limit time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply device including an electrolytic capacitor, an electronic apparatus, a discharge lamp lighting device, and a projector.

  A power supply device mounted on an electronic device such as a projector or a personal computer includes an electrolytic capacitor for maintaining a voltage during an instantaneous power failure. Electrolytic capacitors are also used as filtering and time constant circuits in addition to voltage holding. A power supply device equipped with an electrolytic capacitor causes an increase in ripple voltage, a decrease in voltage holding capability, or an inoperability due to deterioration of the electrolytic capacitor, resulting in a decrease in function or failure of the electronic device itself.

  In order to solve this problem, for example, Patent Document 1 describes a method of monitoring the ripple voltage of a smoothing capacitor and determining deterioration of the smoothing capacitor by comparing with a table of comparison ripple voltage values.

JP 2007-240450 A

  However, the conventional method has a problem that the configuration is complicated because it is necessary to constantly monitor the ripple voltage of the smoothing capacitor and to store a characteristic table.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A rectifying circuit for rectifying an AC voltage supplied from the outside and outputting a DC voltage, an electrolytic capacitor for holding the DC voltage, and a voltage value of the DC voltage from a point in time when the supply of the AC voltage is stopped is predetermined. A voltage monitoring unit that monitors an elapsed time until the voltage value is reached, and outputs a notification signal that notifies the replacement time of the electrolytic capacitor when the elapsed time becomes a predetermined limit time or less. Power supply.

  According to this configuration, it is possible to notify the replacement time of the electrolytic capacitor with a simple circuit configuration, so that the reliability of the power supply device can be improved. The function of the voltage monitoring unit can be implemented by software operating on a microprocessor, or can be implemented by a logic circuit. The voltage when a new electrolytic capacitor reaches the charge capacity is set to Vd, and the time until the electrolytic capacitor is discharged and reaches a predetermined voltage, for example, Vd / 2, is measured in advance, and based on this result. And determine the limit time.

[Application Example 2]
The power supply apparatus may include a display unit that displays a state of the electrolytic capacitor based on the notification signal.

  According to this configuration, it is possible to notify the replacement time of the electrolytic capacitor with a simple circuit configuration, so that the reliability of the power supply device can be improved.

[Application Example 3]
An electronic apparatus comprising the power supply device described above.

  According to this configuration, the user can be notified of the replacement time of the electrolytic capacitor that constitutes the power supply device, so that the reliability of the electronic device can be improved.

[Application Example 4]
A discharge lamp lighting device comprising the power supply device described above.

  According to this configuration, it is possible to notify the replacement time of the electrolytic capacitor with a simple circuit configuration, so that the reliability of the discharge lamp lighting device can be improved.

[Application Example 5]
A projector comprising a discharge lamp and the discharge lamp lighting device described above.

  According to this configuration, it is possible to notify the replacement time of the electrolytic capacitor with a simple circuit configuration, so that the reliability of the projector can be improved.

  Hereinafter, embodiments of a power supply device and a projector will be described with reference to the drawings.

(First embodiment)
<Configuration of projector>
FIG. 1 is a block diagram showing a schematic configuration of the discharge lamp lighting device 10 and the projector 1. As shown in FIG. 1, the projector 1 includes an image projection unit 2 that projects an image, a control unit 4, an operation unit 6, an image processing unit 8, and a discharge lamp lighting device 10.

  First, the image projection unit 2 will be described. The image projection unit 2 includes a discharge lamp 20, three liquid crystal light valves 240R, 240G, and 240B, a projection lens 26, a light valve driving unit 22, and the like.

  FIG. 2 is a configuration diagram showing the configuration of the image projection unit 2 in more detail, and shows an optical path from the light emitted from the discharge lamp 20 to the screen SC.

  As shown in FIG. 2, the image projection unit 2 includes an illumination optical system 23, a color light separation optical system 25, a relay optical system 27, three liquid crystal light valves 240R, 240G, and 240B as light modulation devices, and a cross A dichroic prism 29 and a projection lens 26 are provided.

  The illumination optical system 23 includes, as a light source, a discharge lamp 20 that is a discharge type light source lamp such as an ultra-high pressure mercury lamp or a metal halide lamp, a first lens array 230, a second lens array 232, a polarization conversion element 234, And a superimposing lens 236. The light bundle emitted from the discharge lamp 20 is divided into a large number of minute light bundles by the first lens array 230 in which minute lenses 230a are arranged in a matrix. The second lens array 232 and the superimposing lens 236 are provided such that each of the divided light bundles irradiates the entire three liquid crystal light valves 240R, 240G, and 240B that are illumination targets. For this reason, the light beams are superimposed by the liquid crystal light valves 240R, 240G, and 240B, and the entire liquid crystal light valves 240R, 240G, and 240B are illuminated almost uniformly.

  The polarization conversion element 234 has a function of aligning polarized light having a specific polarization direction so that the light from the discharge lamp 20 can be efficiently used by the liquid crystal light valves 240R, 240G, and 240B. The polarized light emitted from the illumination optical system 23 enters the color light separation optical system 25.

  The color light separation optical system 25 includes a first dichroic mirror 250, a first reflection mirror 252, and a second dichroic mirror 254. The light emitted from the illumination optical system 23 has a different wavelength range. Separate into three colors of light. The first dichroic mirror 250 transmits substantially red light and reflects light having a shorter wavelength than the transmitted light. The red light R that has passed through the first dichroic mirror 250 is reflected by the first reflecting mirror 252 and illuminates the liquid crystal light valve 240R for red light.

  Of the light reflected by the first dichroic mirror 250, the green light G is reflected by the second dichroic mirror 254 and illuminates the liquid crystal light valve 240G for green light. Further, the blue light B passes through the second dichroic mirror 254, passes through the relay optical system 27, and illuminates the liquid crystal light valve 240B for blue light.

  Since the path of the blue light B is longer than the paths of the other color lights, the blue light B is used to prevent the illumination efficiency to the liquid crystal light valve 240B from being reduced due to the divergence of the light beam. A relay optical system 27 is provided in the path. The relay optical system 27 includes an incident side lens 270, a second reflection mirror 272, a relay lens 274, a third reflection mirror 276, and an emission side lens 278. The blue light B emitted from the color light separation optical system 25 is converged in the vicinity of the relay lens 274 by the incident side lens 270 and diverges toward the emission side lens 278.

  Each of the liquid crystal light valves 240R, 240G, and 240B includes a liquid crystal panel 241 in which liquid crystal is sealed between a pair of transparent substrates, and an incident side polarizing plate is provided on each of an incident side surface and an emission side surface of the liquid crystal panel 241. 242 and an exit side polarizing plate 243 are attached. The incident-side polarizing plate 242 and the exit-side polarizing plate 243 can each transmit only polarized light having a specific polarization direction, and the incident-side polarizing plate 242 transmits polarized light having the polarization direction aligned by the polarization conversion element 234. It is possible. For this reason, most of each color light incident on each of the liquid crystal light valves 240R, 240G, and 240B is transmitted through the incident-side polarizing plate 242 and incident on the liquid crystal panel 241.

  On a transparent substrate (not shown) constituting the liquid crystal panel 241, a data line driving circuit 220 and a scanning line driving circuit 222 constituting the light valve driving unit 22 (see FIG. 1) are formed. The scanning line driving circuit 222 is connected to scanning lines Y1 to Yn (not shown) formed on the transparent substrate, and sequentially selects one scanning line from among the plurality of scanning lines Y1 to Yn. The data line driving circuit 220 is connected to data lines X1 to Xm (not shown) formed on the transparent substrate, and supplies signals corresponding to image data to the data lines X1 to Xm. When the data line driving circuit 220 supplies a signal corresponding to image data to each of the data lines X1 to Xm while the scanning line driving circuit 222 selects one scanning line, the selected pixel (selected scanning) is selected. A driving voltage is applied to a horizontal row of pixels connected to the line), and this is repeated for all the scanning lines Y1 to Yn, so that the voltage corresponding to the image data is time-divided for all the pixels on the liquid crystal panel. And an optical image for one screen (one frame) is formed.

  Returning to FIG. 2, the optical image composed of each color light emitted from the liquid crystal light valves 240R, 240G, and 240B enters the cross dichroic prism 29. The cross dichroic prism 29 combines the optical images of the respective colors emitted from the liquid crystal light valves 240R, 240G, and 240B for each pixel to form an optical image representing a color image. The optical image synthesized by the cross dichroic prism 29 is enlarged and projected on the screen SC by the projection lens 26 and displayed as an image.

  Returning to FIG. 1, the control unit 4 includes a CPU (Central Processing Unit) 40, a ROM 42 as a nonvolatile storage unit including a flash ROM (Read Only Memory), and a RAM (Random) used for temporary storage of various data. Access Memory) 44, other electric circuits, and the like, and the CPU 40 operates in accordance with a control program stored in the ROM 42, thereby performing overall control of the operation of the projector 1.

  An operation panel 64 and a remote control 60 that constitute the operation unit 6 are for giving various instructions to the projector 1. When the user operates the operation panel 64, the operation panel 64 corresponds to the operation content of the user. An operation signal is output to the control unit 4. Further, when the user operates the remote controller 60, the remote controller 60 generates an infrared operation signal corresponding to the user's operation content, and the remote control signal receiving unit 62 receives this and transmits it to the control unit 4.

  Next, the image data conversion unit 80, the image data processing unit 82, and the frame memory 84 constituting the image processing unit 8 will be described.

  The image data conversion unit 80 can input image data of various formats from an external image supply device (an image reproduction device, a personal computer, etc.) (not shown), and the input image data is input according to an instruction from the control unit 4. The image data is converted into image data in a format that can be processed by the image data processing unit 82 and output to the image data processing unit 82.

  The image data processing unit 82 can sequentially store (store) input image data in the frame memory 84 and read out the stored image data. Further, according to the instruction of the control unit 4, various kinds of resolution conversion, brightness adjustment, contrast adjustment, sharpness adjustment, etc., for adjusting the resolution to the resolution (number of pixels) of the liquid crystal light valves 240R, 240G, 240B with respect to the read image data Image quality adjustment or processing for synthesizing OSD (on-screen display) images such as menus and messages is performed, and the processed image data is output to the light valve drive unit 22. The light valve driving unit 22 drives the liquid crystal light valves 240R, 240G, and 240B based on the image data input from the image processing unit 8, and modulates the light beam emitted from the discharge lamp 20 into image light.

<Configuration of discharge lamp lighting device>
Next, the configuration of the discharge lamp lighting device according to the first embodiment will be described with reference to FIG. FIG. 3 is a circuit diagram illustrating a configuration of a discharge lamp lighting device including the power supply device according to the first embodiment.

  As shown in FIG. 3, the discharge lamp lighting device 10 includes a switch SW, a power supply device 100, a power control circuit 120, a DC / DC converter 140, an inverter circuit 160, and an igniter circuit 180. Yes.

<Configuration of power supply device>
The power supply apparatus 100 is supplied with an AC voltage AC from an external commercial power supply 1000 via a switch SW, rectifies the AC voltage AC and outputs a DC voltage DC, and an electrolytic capacitor for holding the DC voltage DC. 112 and the elapsed time from when the AC voltage AC is turned off until the voltage value of the DC voltage DC becomes a predetermined voltage value, and when the elapsed time is less than the predetermined limit time, the electrolytic capacitor 112 is replaced. A voltage monitoring unit 114 that outputs a notification signal IS for notifying the timing, a booster circuit 116 that boosts and outputs the DC voltage DC to 380 V, and a display unit 118 that displays the state of the electrolytic capacitor 112 based on the notification signal IS , Is composed of.

<Operation of discharge lamp lighting device>
The power control circuit 120 controls the power DX supplied from the DC / DC converter 140 to the discharge lamp 20. Inverter circuit 160 converts DC power DX output from DC / DC converter 140 into AC power AX. The igniter circuit 180 generates a pulse voltage PS for starting the discharge lamp 20 from the AC power AX. When the discharge lamp 20 is started, the igniter circuit 180 stops functioning, and the AC power AX that is the output of the inverter circuit 160 is supplied to the discharge lamp 20, so that the steady lighting state is maintained.

<Operation of power supply>
Next, the operation of the power supply apparatus will be described with reference to FIG. FIG. 4 is a timing chart showing the operation of the power supply apparatus.

  As shown in FIG. 4, the switch SW transitions from the on state to the off state at time t <b> 0, and the power supply to the power supply device 100 is cut off. The voltage value of the DC voltage DC decreases from time to time when the electrolytic capacitor 112 is fully charged, and finally becomes 0V.

  The voltage monitoring unit 114 measures the elapsed time from the time t0 when the switch SW is turned off to the time t2 when the voltage value of the DC voltage DC reaches the voltage Vd / 2 by a counter circuit (not shown). For example, if the elapsed time of the new electrolytic capacitor 112 is W2 at time points t0 to t2 and the predetermined limit time is W, W2> W, and the notification signal IS has an L level indicating that the electrolytic capacitor 112 is normal. Shall be retained.

  Elapsed time from the time t0 when the electrolytic capacitor 112 becomes old and the switch SW is turned off until the voltage value of the DC voltage DC reaches the voltage Vd / 2 is W1 from time t0 to time t1, and when W1 ≦ W. The notification signal IS shifts to the H level, and the display unit 118 informs the user that the electrolytic capacitor 112 is in the replacement period. As the display unit, an LED (Light Emitting Diode) or the like can be used. When the notification signal IS is L level, a green LED indicating a normal state is lit, and when the notification signal IS is H level, You may make it light up red LED which shows an abnormal condition.

  According to the present embodiment described above, the following effects can be obtained.

  In the present embodiment, since it is possible to notify the replacement time of the electrolytic capacitor with a simple circuit configuration, it is possible to improve the reliability of the power supply device.

  As described above, the embodiment of the power supply device has been described by exemplifying the projector. However, the embodiment is not limited to such an embodiment, and can be implemented in various forms without departing from the gist. Hereinafter, a modification will be described.

  (Modification 1) Modification 1 of the present invention will be described. In the description of the first embodiment, it is exemplified that the display unit 118 can be realized by an LED. However, when the notification signal IS is at an H level, a message such as “Please replace the electrolytic capacitor” is displayed in the image processing unit 8 of the projector. It may be superposed on the image signal, modulated into an optical image by the image projection unit 2 and projected onto the screen.

1 is a block diagram showing a configuration of a projector according to a first embodiment. FIG. 3 is a diagram illustrating a configuration of an optical system of the projector according to the first embodiment. The circuit diagram which shows the structure of the discharge lamp lighting device provided with the power supply device which concerns on 1st Embodiment. The timing diagram which shows operation | movement of a power supply device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Discharge lamp lighting device, 20 ... Discharge lamp, 100 ... Power supply device, 110 ... Rectifier circuit, 112 ... Electrolytic capacitor, 114 ... Voltage monitoring part, 118 ... Display part, 120 ... Power control circuit, 140 ... DC / DC converter , 160 ... inverter circuit, 180 ... igniter circuit, 11000 ... commercial power supply.

Claims (5)

A rectifier circuit that rectifies an AC voltage supplied from the outside and outputs a DC voltage;
An electrolytic capacitor for holding the DC voltage;
The elapsed time from when the supply of the AC voltage is stopped until the voltage value of the DC voltage reaches a predetermined voltage value is monitored, and when the elapsed time falls below a predetermined limit time, the electrolytic capacitor is replaced. And a voltage monitoring unit that outputs a notification signal for notifying the timing.   The power supply device according to claim 1, further comprising a display unit that displays a state of the electrolytic capacitor based on the notification signal.   An electronic apparatus comprising the power supply device according to claim 1.   A discharge lamp lighting device comprising the power supply device according to claim 1.   A projector comprising: a discharge lamp; and the discharge lamp lighting device according to claim 4.

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