JP2014026802A - Discharge lamp device and projection type display device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a lamp from blackening from its coldest point part.SOLUTION: There is provided a discharge lamp device including a discharge lamp, a heater provided at a sealing part of the discharge lamp, and a control part controlling the heater, the control part heating the sealing part of the discharge lamp by controlling the heater when a luminance signal of an input video signal to a projection type display device mounted with the discharge lamp device stays at or lower than a predetermined level or when the projection type display device mounted with the discharge lamp device is set into an economy mode in which output of the discharge lamp is suppressed.

Description

The present invention relates to a discharge lamp device composed of a high-pressure discharge lamp and a projection-type image display device including the same.

For example, liquid crystal projectors and DLP projectors are used in conference presentations, product presentations, home theaters, and the like.

  In the case of a liquid crystal projector, a light source device including a light source lamp for projection, an optical system, and a liquid crystal display panel are provided, and light from the light source lamp enters the liquid crystal panel through the optical system. By being subjected to light modulation, the image displayed on the liquid crystal display panel is enlarged and projected on the screen.

  Generally, a high-pressure mercury lamp is used as the light source. A high-pressure mercury lamp contains a pair of electrodes made of tungsten in a housing made of glass, mercury as a light-emitting substance, and halogen substances such as bromine and iodine for ensuring the lamp life. Reaches 200 atm or more and the lamp surface temperature reaches 1000 ° C.

  In a video display device using a display element having a light modulation action such as a liquid crystal panel, blackening in a dark part tends to occur more easily than a video display device using a self-luminous display element such as a CRT. As one of the methods to suppress the black float and improve the contrast of the displayed image, a method to dynamically change the light emission brightness by dynamically changing the power to the lamp according to the scene of the input video has been proposed. ing.

  When the power to the lamp is dynamically changed according to the scene of the video data, the lamp power is lowered from the rated power in a dark scene, but 70% of the rated power is set when there is no restriction on lighting conditions. For example, when the lighting conditions are limited such as lighting with power saving only for 30 minutes and then lighting with rated power, about 30% of the rated power is the limit.

  The reason why the limit occurs is that the tungsten vaporized from the electrode tip by arc discharge is combined with the halogen substance enclosed in the lamp housing and returned to the electrode tip, so that the lamp life is secured by the so-called halogen cycle. However, when the lamp power is less than 70% of the rated power, the temperature of the coldest spot inside the tube wall of the lamp housing is excessively lowered, so that tungsten evaporated from the electrode tip accumulates at the coldest spot. Occurs and the lamp life is shortened.

  Specifically, the coldest spot portion is a welded portion between the electrode pin of the lamp and the Mo foil inside the tube wall of the lamp housing.

  As a method of extending the lamp life, the lamp power is set to about 80% of the rated power, and the lamp is turned on (so-called eco mode). The temperature at the point does not drop.

  Therefore, light source temperature adjusting means (for example, a fan or halogen heater) that adjusts the video data to a predetermined temperature range based on the luminance data obtained by digitizing the video data, and the light emitted from the light source are received, and the light is converted into the video data. A display device comprising: a light modulation device that performs video display according to modulation according to the light source; and a light source lighting unit that controls the power input to the light source according to the luminance data and adjusts the amount of light incident on the light modulation device. Known (Patent Document 1).

JP 2007-212852 A

  In the above method, the contrast ratio is increased by controlling the top temperature of the surface portion of the lamp, thereby extending the life of the lamp.

  However, when the lamp power is lowered to less than 70% of the rated power, the top temperature is automatically lowered and the coldest spot is lowered to a temperature at which blackening occurs.

  Therefore, in Patent Document 1, an attempt is made to raise the top temperature of the surface portion of the lamp by the light source adjusting means (fan or halogen heater), but there is a distance from the light source adjusting means to the coldest spot, and the light adjusting means. Even if the top temperature of the surface portion of the lamp is raised due to the above, it takes time for the temperature of the coldest spot to rise by the light adjusting means, so there is a drawback that the state of blackening continues. .

  SUMMARY OF THE INVENTION An object of the present invention is to provide a discharge lamp device that can prevent blackening from occurring at the coldest spot of the lamp and a projection display apparatus including the discharge lamp device.

  In order to solve the above problems, a first means of the present invention is a discharge lamp lighting device including a discharge lamp, a heater provided in a sealing portion of the discharge lamp, and a control unit for controlling the heater. When the luminance signal of the input video signal to the projection display device on which the discharge lamp device is mounted continues to be below a predetermined level, the control unit controls the heater to control the discharge lamp sealing unit. Heating is performed.

  In order to solve the above problems, a second means of the present invention is a discharge lamp lighting device comprising a discharge lamp, a heater provided in a sealing portion of the discharge lamp, and a control unit for controlling the heater. When the projection display device on which the discharge lamp device is mounted is set to an eco mode that suppresses the output of the discharge lamp, the control unit controls the heater to heat the sealing portion of the discharge lamp. It is characterized by that.

  In the second means, the power of the discharge lamp in the eco mode may be 70% or less of the rated power of the lamp.

  The first and second means may be a projection display apparatus that modulates and projects light from the discharge lamp of the discharge lamp device.

  By arranging a heater at the coldest spot of the lamp and raising the temperature of the coldest spot locally, the so-called blackening of tungsten electrode material on the tube wall is prevented and the lamp power is reduced. Can extend the life of the lamp.

The figure which shows the structure of a high pressure mercury lamp as an example of a high pressure discharge lamp. FIG. 3 is a partially cutaway perspective view showing a configuration of a lamp unit using a high-pressure mercury lamp as an example of a high-pressure discharge lamp device. The figure which shows the discharge lamp apparatus which lights a high pressure discharge lamp apparatus. The figure which shows the correlation of an input video signal and lamp drive power. The schematic diagram which shows a projection type video display apparatus. FIG. 3 is a flowchart showing heater drive unit control according to the first embodiment. The flowchart figure which shows the heater drive part control of Embodiment 2. FIG.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a high-pressure mercury lamp 100 with a rated power of 220 W as an example of a high-pressure discharge lamp, and is shown in a cross-sectional view at a portion where an electrode is exposed for convenience.

  As shown in FIG. 1, a high-pressure mercury lamp 100 includes a quartz arc tube 101 having a spheroid light-emitting portion 101a and sealing portions 101b and 101c formed at both ends of the light-emitting portion 101a. I have.

  In the light emitting space 108 inside the light emitting unit 101a, mercury 109, which is a light emitting substance, and a rare gas such as argon, krypton, xenon and the like as a starting aid are sealed together with a halogen substance such as iodine or bromine. In this case, the sealed amount of mercury 109 is set to 250 mg / cm 3 or more per inner volume of the light emitting unit 101a, and the sealed pressure during rare gas lamp cooling is set to a range of 0.01 MPa to 1 MPa.

  A pair of tungsten (W) electrodes 102 and 103 are disposed substantially opposite to each other inside the light emitting unit 101a.

  The distance between the tip portions 124 and 134 of the electrodes 102 and 103, that is, the interelectrode distance De is set in the range of 0.5 to 2.0 mm.

  The electrodes 102 and 103 are electrically connected to the molybdenum foils 104 and 105 sealed in the sealing portions 101b and 101c by welding.

  Molybdenum foils 104 and 105 are connected to external leads 106 and 107 led out of the arc tube 101 from the end faces of the sealing portions 101b and 101c.

As the halogen substance, bromine is used in the range of 1 × 10 ⁻¹⁰ to 1 × 10 ⁻⁴ mol / cm 3, and this is the tungsten evaporated from the electrodes 102 and 103 by the so-called halogen cycle action. Thus, the electrode material is prevented from being deposited on the inner surface of the light emitting portion 101a.

The amount of bromine enclosed for making the halogen cycle action function most effectively is particularly preferably in the range of 1 × 10 ⁻⁹ to 1 × 10 ⁻⁵ mol / cm 3 or less.

  The welded portion 110 of the electrode 102 and the molybdenum foil 104, and the welded portion 111 of the electrode 103 and the molybdenum foil 105 have a maximum operating temperature of 1200 ° C. and little change in resistance, and a cantal wire 112 of iron, chromium, and aluminum alloy is wound as a heater. It is connected to a DC power source 113. The DC power source 113 corresponds to a heater driving unit as will be described later.

  FIG. 2 is a partially cutaway perspective view showing the configuration of the lamp unit 1 incorporating the high-pressure mercury lamp 100.

  As shown in FIG. 2, the lamp unit 1 has a base 201 attached to one end of the arc tube 101 of the high-pressure mercury lamp 100, a terminal 204 drawn out through a spacer 202, and the reflection mirror 2. Electric current is supplied through the lead wires 205 drawn out through the through-holes 206 provided.

  A Kanthal wire 112 as a heater is also drawn out and connected to a heater driving unit.

  FIG. 3 is a view showing a discharge lamp device for lighting the lamp unit 1.

  The DC power supply circuit 300 includes, for example, a rectifier circuit, generates a DC voltage from household AC 100 V, and outputs the DC voltage to the lamp driving unit 301, the heater driving unit 302, and the control unit 303.

  An input video signal from the video signal input terminal 305 or an input signal from the eco mode switching signal input terminal 306 is input to the control unit 303. An output signal from the control unit 303 is input to the lamp driving unit 301 and the heater driving unit 302. The lamp 200 is driven by the output of the lamp driving unit 301. Further, the heater of the lamp 200 is driven by the output of the heater driving unit 302.

  When an input video signal from the video signal input terminal 305 is input, the control unit 303 detects a luminance signal of the input video signal.

  An example of the correlation between the luminance signal of the input video signal and the lamp driving power will be described with reference to FIG.

  When the maximum value of the luminance signal for each field is 100% of the input dynamic range, the lamp driving unit 301 is allocated to the maximum (rated power of the lamp), and when the input dynamic range is 0%, the lamp driving unit 301 is the minimum. Assigned to (MIN).

  When a luminance signal having a gradation level between 100% and 0% of the input dynamic range is input, the lamp driver 301 is interpolated to a value between the maximum and minimum.

  Thus, in the case of a bright scene where the level of the input video signal is high, the lamp driving power is increased and the image is displayed brightly. When it is determined that the input signal level is low and the scene is dark, the lamp driving power is lowered and the display is dark. This improves the contrast of the displayed video that the user sees and feels.

  FIG. 5 is a schematic diagram showing a basic configuration of an L-shaped projection display device in which a general illumination optical system is linearly arranged. In the figure, white light emitted from the lamp unit 1 is emitted as parallel light by a parabolic reflecting mirror 2, passes through a UV-IR cut filter UVIR that removes infrared and ultraviolet components, and passes through a convex lens group. The light beam is split by a so-called integrator optical system including the first and second fly-eye lenses 3 and 4 that are configured. The respective light beams converge and enter the polarization conversion element 5, and are emitted with the polarization directions aligned.

  Then, the light whose polarization direction is aligned passes through the condenser lens 6 and the like, and then the red to green band light is transmitted and the blue band light is reflected by the dichroic mirror 7.

  The blue band light reflected by the dichroic mirror 7 and whose optical path is changed by 90 degrees is changed by the total reflection mirror 8 and the optical path is changed by 90 degrees, and the blue band light component images of the liquid crystal display elements 10R, 10G and 10B are displayed via the condenser lens 9B. 10B, and is optically modulated according to the input signal. The liquid crystal display element is provided with an incident side polarizing plate PI and an output side polarizing plate PO.

  The light-modulated light enters the dichroic prism 11, enters the projection lens 20 with the optical path changed by 90 degrees in the dichroic prism, is enlarged and projected, and forms an image on a screen (not shown).

  On the other hand, the red to green band light passes through the dichroic mirror 7 and enters the dichroic mirror 12. Since the dichroic mirror 12 has a characteristic of reflecting the green band light, the green band light is reflected here, its optical path is changed by 90 degrees, and enters the liquid crystal display element 10G through the condenser lens 9G. The light is modulated in accordance with the input signal. The light-modulated green band light enters the dichroic prism 11 and the projection lens 20 in this order, and is enlarged and projected to form an image on the screen.

  The red band light transmitted through the dichroic mirror 12 is incident on the liquid crystal display element 10R through the lenses 13 to 15 and the total reflection mirrors 16 and 17, where it is optically modulated according to the input signal. The light-modulated red band light is incident on the dichroic prism 11, is incident on the projection lens 50 with the optical path changed by 90 degrees by the dichroic prism 11, is magnified and projected, and is imaged on the screen.

  Based on FIG. 6, the control of the heater driving unit 302 by the luminance signal of the input video signal will be described in detail.

  Since the lamp driving unit 301 is controlled based on the luminance signal of the input video signal, the lamp driving power is low when the luminance signal of the force video signal is a dark signal level, and the luminance signal of the input video signal is a bright signal level. In some cases, the lamp driving power is high.

  As a matter of course, when the lamp driving power is low, the lamp unit 1 becomes low temperature, and when the lamp driving power is high, the lamp unit 1 becomes high temperature.

  For example, when the luminance signal of the input video signal continues at a dark level, the lamp driving power continues to be low, so that the temperature at the coldest spot of the lamp unit 1 is too low and blackening may occur.

  Therefore, in the present embodiment, control based on the luminance signal of the input video signal as shown in the flowchart of FIG. 6 is performed.

The lamp unit 1 performs lighting based on the luminance signal of the input video signal as shown in FIG. (S1)
Next, in S2, it is detected whether or not the APL, which is the average value of the bright signals of the input video signal of a predetermined frame, for example, four frames, is a dark signal level equal to or lower than the predetermined value.

  In S2, if APL is a dark signal level equal to or less than a predetermined value, one flag is counted. In S2, if APL is not a dark signal level equal to or less than a predetermined value, the flag that has been counted is canceled and the process returns to S1.

  In S2, when APL is a dark signal level equal to or less than a predetermined value, it is determined in S3 whether or not the flag is continuously counted a predetermined number of times. Here, the predetermined number of times is four. If four flags are not counted in S3, the process returns to S1 while retaining the counted number of flags.

If four flags are counted in S3, the lamp driving power is kept low, and it is presumed that the temperature at the coldest spot of the lamp unit 1 is lowered. The drive unit 302 is operated to turn on the heater of the lamp unit 1. (S4)
When a predetermined time elapses after the heater of the lamp unit 1 is turned on (YES in S5), the process returns to S1.

Thus, by controlling the heater of the lamp unit 1 based on the luminance signal of the input video signal, it is possible to prevent a temperature drop at the coldest spot of the lamp unit 1 without using a temperature sensor, Generation of blackening can be prevented.
(Embodiment 2)
FIG. 7 shows a second embodiment relating to heater drive unit control.

  In addition, about the same structure as Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

In FIG. 7, the lamp unit 1 performs lighting based on the luminance signal of the input video signal as in the first embodiment. (S21)
Next, in S22, it is determined whether or not a signal is input to the eco mode switching signal terminal. If no signal is input to the eco mode switching signal terminal, the process returns to S21.

In S22, when a signal is input to the eco mode switching signal terminal, that is, when the eco mode is selected, the lamp driving power is set to the minimum (MIN) regardless of the luminance signal level of the input video signal. . (S23)
When a predetermined time elapses after the eco mode is set (YES in S24), the control unit 303 operates the heater driving unit 302 to turn on the heater of the lamp unit 1 (S25).

  Thereafter, when the signal is input again to the eco-mode switching signal terminal (YES in S26), that is, when the eco-mode is canceled, the control unit 303 turns off the heater driving unit 302 (S27) and the heater of the lamp unit 1 And return to S21.

  Thus, conventionally, the minimum (MIN) lamp driving power is about 70% of the rated power, and when the lighting conditions are limited (for example, the lamp is lit with power saving only for 30 minutes, then the rated power is Is limited to about 30% of the rated power. However, by providing a heater in the sealing part of the high-pressure discharge lamp of the present invention, it is minimum to 10% of the rated power without limiting the lighting conditions. (MIN) could be set.

  The discharge lamp device according to the present invention is a so-called blackening in which tungsten, which is an electrode material, is deposited on the tube wall by disposing a heater in the sealing portion of the lamp and having a structure that locally raises the temperature of the coldest spot. This can extend the life of the lamp when the lamp power is reduced.

1: Lamp unit 100: High-pressure mercury lamp 112: Kanthal wire (heater)
300: DC power supply circuit 301: Lamp driving unit 302: Heater driving unit 303: Control unit 305: Video signal input terminal 306: Eco mode switching signal input terminal

Claims (4)

A discharge lamp device comprising a discharge lamp, a heater provided in a sealing portion of the discharge lamp, and a control unit for controlling the heater,
When the luminance signal of the input video signal to the projection display device on which the discharge lamp device is mounted continues to be below a predetermined level, the control unit controls the heater to heat the sealing unit of the discharge lamp. The discharge lamp device characterized by performing. A discharge lamp lighting device comprising a discharge lamp, a heater provided in a sealing portion of the discharge lamp, and a control unit for controlling the heater,
When the projection display device on which the discharge lamp device is mounted is set to an eco mode that suppresses the output of the discharge lamp, the control unit controls the heater to heat the sealing portion of the discharge lamp. A discharge lamp device characterized by the above.   The discharge lamp device according to claim 2, wherein the electric power of the discharge lamp when the eco mode is set is 70% or less of the rated power of the lamp.   The projection display apparatus according to claim 1, wherein light from a discharge lamp of the discharge lamp device is modulated and projected.

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