JP2002100489A - Discharge lamp lighting device and backlight unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device and a backlight unit, capable of detecting abnormalities of a double tube discharge lamp. SOLUTION: In this backlight unit 1, a double-tube discharge lamp 2, a temperature sensor 3, a luminance sensor 4, a liquid crystal display part 5, a light- transmitting plate 6, an unillustrated control means and a lighting device are constituted in a unit shape. This embodiment fetches the output of the temperature sensor 3 and the luminance sensor 4, detects whether the output has become a prescribed luminance value set by an arithmetic circuit, detects it as an abnormal state of impairing airtightness of a arc tube or an outer tube of the double- tube discharge lamp 2, when this detecting result causes errors from a preset luminance value, and detects it as an abnormal state of impairing airtightness of the arc tube or the outer tube of the double-tube discharge lamp 2, when a detecting result of lamp voltage causes errors from a preset lamp voltage value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a discharge lamp lighting device for a double tube discharge lamp and a backlight unit having the double tube discharge lamp.

2. Description of the Related Art In recent years, as a discharge lamp of a display device using a backlight unit, a single tube fluorescent lamp has been widely used. It is known that the rising characteristics of this fluorescent lamp deteriorate as the ambient environment becomes lower due to a decrease in luminous efficiency due to a decrease in mercury vapor pressure.
Therefore, when the display device is used in a low-temperature atmosphere, sufficient brightness cannot be obtained when the backlight unit is started.

As a prior art for solving this problem, the present applicant has proposed Japanese Patent Application Laid-Open No. Hei 10-333142. This conventional technique uses a fluorescent lamp having a double tube structure as a light source of a backlight unit and uses a heat radiating means for promoting heat radiation of the light source, thereby obtaining a stable backlight characteristic over a wide temperature range. And a liquid crystal display device using the same.

[0003] The fluorescent lamp of the double tube structure used in the prior art hermetically surrounds the arc tube with an outer tube such as a glass tube.
In this structure, the pressure between the arc tube and the outer tube is reduced. According to the fluorescent lamp having such a double tube structure, since a heat insulating effect is generated between the arc tube and the outer tube which are in a reduced pressure atmosphere, the mercury vapor pressure can be kept in a stable state even when the outside air is in a low temperature atmosphere. The characteristics of the fluorescent lamp can be used effectively without being affected by the temperature of the outside air.

However, in a fluorescent lamp having a double tube structure, even if one of the arc tube and the outer tube is damaged or cracked and the airtightness is impaired, the airtightness of the other tube is reduced. Is not damaged, there is no inconvenience due to the fact that the discharge lamp has a single-tube structure consisting essentially of one bulb.

Therefore, a backlight unit using a fluorescent lamp having a double tube structure recognizes a state in which the arc tube or the outer tube of the fluorescent tube having a double tube structure has some trouble from the outside. In addition to the difficulty, it is sometimes difficult for the user to determine that the originally satisfied specifications such as the brightness of the light source of the backlight unit and the rising characteristics are not satisfied.

[0005] The present invention has been made in view of the above,
An abnormality of the double tube discharge lamp can be detected, and
Provided is a discharge lamp lighting device and a backlight unit that can externally recognize an abnormality of a double tube discharge lamp.

According to a first aspect of the present invention, there is provided a discharge lamp lighting device, which is formed integrally with a light emitting tube constituting a discharge space by surrounding the light emitting tube and welding both ends of the light emitting tube. A double-tube discharge lamp including an outer tube provided so that a heat-insulating layer is formed between the arc tube and the arc tube; a temperature-sensitive element for measuring an ambient temperature of the double-tube discharge lamp; Brightness detection means for detecting the brightness of the light emitted from the discharge lamp; detection data of the temperature sensing element and the brightness detection means being input, and detecting an abnormality of the double tube discharge lamp based on the input detection data Control means for performing;
It is characterized by having.

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

The arc tube is made of a glass bulb having a phosphor layer on its inner surface, and is preferably made of a soft glass such as soda lime glass or lead glass, but may be made of a hard glass such as borosilicate glass if necessary. The material is not particularly limited.
The cross-sectional shape is usually circular, but if necessary, it may be non-circular, for example, elliptical or any other cross-sectional shape. Further, the shape in the longitudinal direction can be a desired shape such as an annular shape, a semicircular shape, an L-shape, a U-shape, a W-shape as well as a straight pipe.

In general, a cold cathode electrode is used for the arc tube, but a hot cathode can be used as long as it can be housed in a thin arc tube, or a tube having an electrode on the outer surface of the arc tube can be used. Can also.

Further, the arc tube has a discharge medium in the bulb, and this discharge medium uses mercury and a rare gas such as argon in many cases, but uses a simple or mixed gas of another rare gas. You may.

The outer tube is preferably made of the same material as the arc tube. However, if the outer tube does not have a large difference in the coefficient of thermal expansion and does not hinder the workability with the bulb, a different material is used. Is also good.

The term “weld to both ends of the arc tube” means that one or both of the bulbs of the arc tube and the outer tube are fused and fixed. The welding may be performed with a welding member having a value interposed therebetween.

The temperature sensitive element is, for example, a thermistor, and is preferably provided directly on the outer surface of the double tube discharge lamp. However, if the ambient temperature of the double tube discharge lamp can be detected, it is provided near the outer tube. Alternatively, it may be provided at a location separated from the outer tube so that the ambient temperature of the discharge lamp lighting device can be detected, and if the detected temperature is configured to be input to control means described later, it is particularly preferable. Not limited.

The luminance detecting means is, for example, a luminance sensor such as a luminance meter or a photo sensor.

The luminance detecting means may be provided so as to detect the surface luminance of the outer tube or the arc tube of the double tube discharge lamp, or to detect the luminance of the light emitting surface of the backlight unit described later. It may be provided as follows. Providing the backlight unit so as to detect the luminance of the light emitting surface has a greater degree of freedom in the arrangement of the luminance detecting means than providing the luminance detecting means around a double tube discharge lamp in which various components are arranged. At the same time, the luminance of the double tube discharge lamp and the luminance of the backlight unit do not exactly correspond to each other, so that accurate luminance of the backlight unit can be detected.

The control means includes an arithmetic circuit using electronic components such as a microcomputer. Then, when the detection data of the temperature sensing element and the luminance detecting means is input to the arithmetic circuit, the double tube discharge occurs due to the difference between the detection data from the temperature sensing element and the luminance detecting means and the setting range preset in the control means. Detects lamp status. As a result of detecting the state of the double tube discharge lamp, if the difference from the set range is large, it is recognized as an abnormality of the double tube discharge lamp and the recognized abnormality information can be output.

The operation of the first aspect of the present invention will be described.

First, assuming that the airtightness of the arc tube of a double tube discharge lamp is impaired, a discharge lamp having a single tube structure substantially consisting of a bulb having only an outer tube is obtained. With such a structure, the heat insulating effect between the arc tube and the outer tube is lost, and the difference between the luminance previously set in the control means and the luminance detected by the luminance detection means is remarkable especially at a low temperature. Therefore, when the difference between the luminance preset in the control means and the luminance detected by the luminance detecting means is large with respect to the ambient temperature detected by the temperature-sensitive element, an abnormality occurs in the double tube discharge lamp. Is recognized by the control means.

The "difference between the set luminance and the luminance detected by the luminance detecting means" takes into account an error range which is expected in advance such as a decrease in luminance over time.

If the airtightness of the outer tube of the double tube discharge lamp is impaired, the discharge lamp has a single tube structure substantially consisting of a bulb having only an arc tube. With such a structure, the heat insulating effect between the arc tube and the outer tube is lost, and the difference between the luminance previously set in the control means and the luminance detected by the luminance detection means is remarkable especially at a low temperature. The operation of the control means thereafter is the same as the control when the airtightness of the arc tube is impaired.

The control by the control means is such that even when the airtightness of one of the arc tube and the outer tube is impaired, the difference in luminance appears remarkably at low temperatures and at room temperature there is no large difference. If it has characteristics, the ambient temperature to be controlled can be set to an arbitrary range in a low temperature range.

According to the first aspect of the present invention, the difference between the detection data detected by the temperature sensing element and the luminance detecting means and the preset luminance with respect to the preset ambient temperature is calculated by the control means. An abnormality of the heavy tube discharge lamp can be detected.

A discharge lamp lighting device according to a second aspect of the present invention is a discharge lamp lighting device which is formed integrally with a light emitting tube constituting a discharge space by welding the light emitting tube to surround the light emitting tube and to both ends of the light emitting tube. A double-tube discharge lamp having an outer tube provided so as to form a heat insulating layer; a temperature-sensitive element for measuring an ambient temperature of the double-tube discharge lamp; Lamp voltage detecting means for detecting;

Control means for inputting detection data of the temperature sensing element and the lamp voltage detection means, and detecting abnormality of the double tube discharge lamp based on the input detection data;
It is characterized by having.

The lamp voltage detecting means is provided so as to be able to detect the voltage at both ends of the double tube discharge lamp, and is configured so that the detection data is inputted to the control means.

In the present invention, "luminance" and "luminance detecting means" are replaced with "lamp voltage detecting means" and "lamp voltage detecting means", respectively.

The operation of the second aspect will be described.

First, when the airtightness of the arc tube of the double tube discharge lamp is impaired, a discharge lamp having a single tube structure substantially consisting of a bulb having only an outer tube is obtained. With such a structure,
The heat insulating effect between the arc tube and the outer tube is lost, and the difference between the lamp voltage preset in the control means and the lamp voltage detected by the lamp voltage detection means appears. Therefore, if the difference between the lamp voltage detected by the control means and the lamp voltage detected by the lamp voltage detection means is large with respect to the ambient temperature detected by the temperature sensing element, the double tube discharge lamp is abnormal. The control means recognizes that the error has occurred.

If the airtightness of the arc tube is impaired, the gas inside the arc tube flows into the outer tube side due to the reduced pressure between the arc tube and the outer tube, and the gas pressure decreases. . When the gas pressure is reduced in this manner, the change in the lamp voltage is small, but the setting for recognizing that an abnormality has occurred in the arc tube is set in consideration of the above circumstances.

If the airtightness of the outer tube of the double-tube discharge lamp is impaired, the discharge lamp has a single-tube structure consisting essentially of a bulb having only an arc tube. With such a structure, the heat insulating effect between the arc tube and the outer tube is lost, and the difference between the lamp voltage set in the control means in advance and the lamp voltage detected by the lamp voltage detection means becomes remarkable. The operation of the control means thereafter is the same as the control when the airtightness of the arc tube is impaired.

According to the second aspect of the present invention, the difference between the detection data detected by the temperature sensing element and the lamp voltage detecting means and the lamp voltage with respect to a preset ambient temperature is calculated by the control means. An abnormality of the double tube discharge lamp can be detected.

A discharge lamp lighting device according to a third aspect of the present invention is configured such that an arc tube constituting a discharge space is formed integrally with the both ends of the arc tube by welding and surrounding the arc tube. A double-tube discharge lamp having an outer tube on which a heat insulating layer is formed; a temperature-sensitive element for measuring an ambient temperature of the double-tube discharge lamp; and detecting brightness of light emitted from the double-tube discharge lamp A lamp detecting means for detecting a lamp voltage of a double tube discharge lamp; detection data of a temperature sensing element, a luminance detecting means and a lamp voltage detecting means being inputted, and the inputted detection data Control means for detecting an abnormality of the double tube discharge lamp based on the above.

According to the third aspect of the present invention, the abnormality of the double tube discharge lamp can be detected more reliably by using the temperature sensing element, the luminance detecting means and the lamp voltage detecting means.

According to a fourth aspect of the present invention, there is provided the discharge lamp lighting device according to any one of the first to third aspects, wherein the control means has a function of detecting an abnormality of the double tube discharge lamp, It has a function of controlling the lamp current to a predetermined lamp current based on the detection data of the element.

In addition to detecting the state of the double tube discharge lamp, the control means supplies a predetermined lamp current according to the ambient temperature of the double tube discharge lamp inputted from the temperature sensing element. ing. The double-tube discharge lamp has a heat insulating effect between the arc tube and the outer tube, which is a depressurized atmosphere, so that the temperature inside the arc tube tends to rise, and if the temperature rises excessively, the mercury vapor pressure decreases and the brightness decreases. Decrease. Therefore, it is preferable that a lamp current suitable for the characteristics of the ambient temperature and the brightness of the double tube discharge lamp can be supplied.

According to the fourth aspect of the present invention, in addition to the function of detecting the abnormality of the double tube discharge lamp, the control means has a function of controlling the lamp current to a predetermined value based on the detection data of the temperature sensing element. As a result, if there is no abnormality in the state of the double tube discharge lamp, required specifications such as brightness or rising characteristics of the double tube discharge lamp can always be satisfied.

According to a fifth aspect of the present invention, in the discharge lamp lighting device according to any one of the first to fourth aspects, when the control unit recognizes that the double tube discharge lamp is abnormal, the control unit controls the double tube discharge lamp. The supply of the lamp current is stopped.

According to the fifth aspect of the present invention, when the control means recognizes that the double-tube discharge lamp is abnormal, the supply of the lamp current to the double-tube discharge lamp is stopped. An abnormality of the heavy tube discharge lamp can be recognized from the outside.

According to a sixth aspect of the present invention, in the discharge lamp lighting apparatus according to any one of the first to fourth aspects, when the control unit recognizes that the double-tube discharge lamp is abnormal, the control unit controls the discharge of the double-tube discharge lamp. It is characterized by having an information transmitting means for notifying the abnormality to the outside.

The information transmitting means is preferably provided with a light emitting element or the like.

When the control unit recognizes the abnormality of the double tube discharge lamp, it outputs the recognized abnormality information to the information transmission unit, and turns on the light emitting element of the information transmission unit. Thereby, the user can be notified of the abnormality or replacement of the double tube discharge lamp.

According to the sixth aspect of the present invention, when the control means recognizes that the double tube discharge lamp is abnormal, the control means includes an information transmitting means for notifying the abnormality of the double tube discharge lamp to the outside. The user can easily recognize the replacement of the tube discharge lamp.

According to a seventh aspect of the present invention, there is provided the backlight unit provided in the apparatus main body having an opening;
6. A discharge lamp lighting device according to any one of items 6 to 6, and a display unit provided at an opening of the device main body so as to irradiate light from the double tube discharge lamp.

The shape, structure and material of the apparatus main body are not limited as long as the apparatus main body accommodates the double tube discharge lamp therein and has an opening for providing a display section described later.

The display section may be any display means such as a translucent flat display panel, and is illuminated with light from a double tube discharge lamp to display characters, designs, images or images. Although a means is provided, the material and structure are not particularly limited.

The display section may be provided at a position protruding from the opening of the apparatus body, or may be provided at a position substantially flush with the opening or at a position not protruding.

The backlight unit may be of a direct type or a side light type, and is not particularly limited as long as it has a function as a backlight.

Note that the direct type is a configuration in which light control means such as a diffusion plate is provided immediately below the display unit, and a double tube discharge lamp is provided immediately below the light control means. The sidelight method has a light exit surface provided on one surface of a light guide unit using a light guide unit such as a light guide plate, and a light incident surface provided on an end surface substantially perpendicular to the light exit surface. The structure is such that the emission surface is provided in the device body so as to face the opening of the device body, and the double tube discharge lamp is provided on the light incidence surface of the light guide means.

The luminance detecting means may be provided so as to detect the luminance of the light guiding means when the sidelight system is used.

According to the seventh aspect of the present invention, the discharge lamp lighting device according to any one of the first to sixth aspects has an operation.

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

FIG. 1 is an exploded perspective view showing a backlight unit according to an embodiment of the present invention, FIG. 2 is a graph showing luminance characteristics of a double tube discharge lamp of the backlight unit, and FIG. FIG. 4 is a graph showing lamp voltage characteristics of the double tube discharge lamp of FIG.

In FIG. 1, 1 is a backlight unit, 2 is a double tube discharge lamp, 3 is a temperature sensor as a temperature sensing element, 4 is a luminance sensor as luminance detecting means, and 5 is a liquid crystal display unit as a display unit. Reference numeral 8 denotes a casing which is a main body of the apparatus.

The backlight unit 1 comprises a double tube discharge lamp 2, a temperature sensor 3, a brightness sensor 4, a liquid crystal display 5,
The light guide 6, control means (not shown), a lighting device, and the like are configured in a unit shape.

The double tube discharge lamp 2 will be described with reference to FIGS. In the figure, reference numeral 21 denotes an arc tube, and 22 denotes an outer tube.

The arc tube 21 is drawn out from an elongated airtight glass bulb 21a, a pair of cold cathode type electrodes 21b sealed at both ends of the glass bulb 21a, and an end of the glass bulb 21a from the electrode 21b. The lead wire 21c, the phosphor layer 21d formed on the inner surface of the glass bulb 21a, and a rare gas mainly composed of mercury and argon as a discharge medium sealed in the glass bulb 21a. The arc tube 21 has a glass bulb 21a having an outer diameter of 2 mm and a wall thickness of 0.1 mm.
3 mm.

The outer tube 22 has an outer diameter of 4 mm and a thickness of 0.3 mm.
In a concentric positional relationship with the arc tube 21a, both ends are integrated with both ends of the glass bulb 21a of the arc tube 21 by welding. The gap length is 0.2 mm.

The double-tube discharge lamp 2 thus formed
Is bent at an intermediate portion in the longitudinal direction as shown in FIG.
The light incident surfaces 6a and 6 of the light guide 6 described later
a.

The temperature sensor 3 includes a thermistor and the like.
It is fixed in direct contact with the outer surface of the double tube discharge lamp 2 using the shrink tube 32.

The luminance sensor 4 is a luminance meter, and a sensor main body 41 for measuring luminance is attached to an opening 8a formed on the back surface of the casing 8, and is integrally fixed to a backlight unit. Is measured.

The control means is provided with an arithmetic circuit having electronic parts such as a microcomputer, for example, and calculates the input luminance sensor 3, temperature sensor 4, and output of the lamp voltage and the like by the arithmetic circuit, and performs a double tube operation. A lighting device having an abnormality of the discharge lamp 2 or an inverter device controls a lamp current supplied to the double tube discharge lamp 2.

In the liquid crystal display section 5, a pair of molecular alignment films (not shown) are disposed between a pair of transparent electrodes (not shown) formed in a matrix. A liquid crystal (not shown) is disposed between them to form a liquid crystal display unit 5, and this liquid crystal display unit 5 is disposed on a light emitting surface 6b, which will be described later, as shown in FIG. .

The light guide 6 has a plate-shaped main body made of a transparent acrylic resin. As shown in FIG. 1, the light incident surfaces 6a, 6a are formed on the side end surfaces, and are substantially perpendicular to the light incident surfaces 6a. A light emitting surface 6b is formed on one surface. A light diffusion sheet and a prism sheet (not shown) are attached to the light exit surface 6b for improving the brightness.

The casing 8 is made of a synthetic resin having a high reflectivity, has a rectangular opening, and has an inner surface formed as a reflector having light reflection characteristics. The casing 8 houses a control means and a lighting device.

Next, an example of the operation of the control means of the backlight unit 1 will be described with reference to FIGS.

2A and 3A show the characteristics of the double-tube discharge lamp 2, and FIGS. 2B and 3B show the characteristics of the double-tube discharge lamp 2 having only the arc tube.

First, the ambient temperature of the backlight unit 11 is measured based on the output value of the temperature sensor 3 simultaneously with the lighting of the double tube discharge lamp 2.

Then, based on the correspondence between the preset ambient temperature and the lamp current, a lamp current corresponding to the input ambient temperature is supplied.

Next, after a lapse of a predetermined time, for example, 30 seconds later, the output of the luminance sensor 4 is fetched, and it is detected whether or not the luminance has reached the predetermined luminance value set by the arithmetic circuit. That is, the luminance characteristics of the double tube discharge lamp 2 of the backlight unit 11 of the present embodiment are set so that the luminance can be obtained at a lower temperature than that of the discharge lamp having the single tube structure as shown in FIG. Therefore, when an error occurs between the detection result and the set luminance value, the double-tube discharge lamp 2
Is detected as an abnormal state in which the airtightness of the arc tube 21 or the outer tube 22 is impaired. When an abnormality is detected, the operation of stopping the supply of the lamp current or outputting the information to an information transmitting means (not shown) provided with a light emitting element or the like to turn on the light emitting element to notify the user of the abnormality is performed. Do.

In addition to the above, the control means can also detect the lamp voltage. As shown in FIG. 3, the lamp voltage of the double-tube discharge lamp 2 of the backlight unit 11 of the present embodiment has such characteristics that the lamp voltage is lower than that of the single-tube discharge lamp. Therefore, if the detection result of the lamp voltage has an error from the set lamp voltage value, it is detected that the airtightness of the arc tube 21 or the outer tube 22 of the double tube discharge lamp 2 is impaired. I do. Subsequent steps are the same as in the case of the luminance detection described above.

These controls are performed by the double tube discharge lamp 2.
The characteristics may vary depending on the lamp characteristics, the unit mounting state, and the use over time. Therefore, the setting may be made in consideration of the error range of these changes.

If there is no abnormality in the double tube discharge lamp 2, the lamp current is controlled so that the luminance is stable when the luminance is stable. This is because even if the ambient temperature is low, the ambient temperature gradually rises due to the heat of the engine, the lighting circuit, and the double tube discharge lamp 2 itself. More stable luminance can be realized. It is also effective to control the lamp current not only when the luminance is stable but also when the double tube discharge lamp 2 rises.

According to the present embodiment, the difference between the detection data detected by the temperature sensor 3 and the luminance sensor 4 and a predetermined value with respect to the ambient temperature set in advance is calculated by the control means, so that the double pipe An abnormality of the discharge lamp 2 can be detected.

In addition, since lamp voltage detection can also be detected, abnormality of the double tube discharge lamp 2 can be detected more reliably.

In addition, the control means has a function of detecting a malfunction of the double tube discharge lamp 2 and a function of controlling a predetermined lamp current based on the detection data of the temperature sensor 3 so that the double tube discharge lamp 2 has a double function. If there is no abnormality in the state of the tube discharge lamp 2, required specifications such as the brightness or the rising characteristics of the double tube discharge lamp 2 can always be satisfied.

According to the first aspect of the present invention, the difference between the detection data detected by the temperature sensing element and the luminance detecting means and the preset luminance with respect to the preset ambient temperature is calculated by the control means. In addition, the abnormality of the double tube discharge lamp can be detected.

According to the second aspect of the present invention, the control means calculates the difference between the detection data detected by the temperature sensing element and the lamp voltage detecting means and the lamp voltage with respect to a preset ambient temperature. An abnormality of the double tube discharge lamp can be detected.

According to the third aspect of the present invention, the abnormality of the double tube discharge lamp can be detected more reliably by using the temperature sensing element, the luminance detecting means and the lamp voltage detecting means.

According to the fourth aspect of the present invention, in addition to the function of detecting the state of the double tube discharge lamp, the control means has a function of controlling the lamp current to a predetermined lamp current based on the detection data of the temperature sensing element. As a result, if there is no abnormality in the state of the double tube discharge lamp, required specifications such as brightness or rising characteristics of the double tube discharge lamp can always be satisfied.

According to the fifth aspect of the present invention, when the control means recognizes that the double-tube discharge lamp is abnormal, the supply of the lamp current to the double-tube discharge lamp is stopped, so that the brightness is greatly reduced. An abnormality of the heavy tube discharge lamp can be recognized from the outside.

According to the invention of claim 6, when the control means recognizes that the double tube discharge lamp is abnormal, the control means is provided with an information transmitting means for notifying the abnormality of the double tube discharge lamp to the outside, so that the double tube discharge lamp is provided. The user can easily recognize the replacement of the tube discharge lamp.

According to the seventh aspect of the present invention, the operation of the discharge lamp lighting device according to any one of the first to sixth aspects is provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a backlight unit according to an embodiment.

FIG. 2 is a graph showing luminance characteristics of the double-tube discharge lamp 2 and the single-tube structure discharge lamp at ambient temperature.

FIG. 3 is a graph showing characteristics of a lamp voltage at an ambient temperature of the double-tube discharge lamp 2 and the single-tube structure discharge lamp.

FIG. 4 is an enlarged sectional view of a main part showing the double tube discharge lamp 2 of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Backlight unit 2 ... Double tube discharge lamp 3 ... Temperature sensor 4 ... Brightness sensor 5 ... Liquid crystal display

Claims (7)

[Claims] An arc tube which forms a discharge space and which is formed integrally with the arc tube by welding and surrounding both ends of the arc tube so that a heat insulating layer is formed between the arc tube and the arc tube. A double-tube discharge lamp having an outer tube provided; a temperature-sensitive element for measuring an ambient temperature of the double-tube discharge lamp; and a luminance detection for detecting luminance of light emitted from the double-tube discharge lamp Means for receiving detection data of the temperature sensing element and the luminance detecting means, and detecting abnormality of the double tube discharge lamp based on the input detection data;
A discharge lamp lighting device, comprising: 2. An arc tube which forms a discharge space, and is formed by welding and surrounding the arc tube and integrally formed with both ends of the arc tube by welding, so that a heat insulating layer is formed between the arc tube and the arc tube. A double-tube discharge lamp having an outer tube provided; a temperature-sensitive element for measuring an ambient temperature of the double-tube discharge lamp; a lamp voltage detecting means for detecting a lamp voltage of the double-tube discharge lamp; Control means for receiving detection data of the temperature sensing element and the lamp voltage detection means and detecting abnormality of the double tube discharge lamp based on the input detection data; apparatus. 3. An arc tube which forms a discharge space, is formed integrally with the both ends of the arc tube by welding and surrounding the arc tube, and a heat insulating layer is formed between the arc tube and the arc tube. A double-tube discharge lamp having an outer tube provided; a temperature-sensitive element for measuring an ambient temperature of the double-tube discharge lamp; and a luminance detection for detecting luminance of light emitted from the double-tube discharge lamp Means; a lamp voltage detecting means for detecting a lamp voltage of the double tube discharge lamp; and detection data of the temperature sensing element, the luminance detecting means, and the lamp voltage detecting means, and two based on the inputted detection data. Control means for detecting abnormality of the double tube discharge lamp; 4. The control means has a function of controlling a predetermined lamp current based on detection data of the temperature sensing element, in addition to a function of detecting an abnormality of the double tube discharge lamp. Item 4. The discharge lamp lighting device according to any one of Items 1 to 3. 5. The discharge lamp according to claim 1, wherein the control means stops supply of a lamp current to the double tube discharge lamp when the double tube discharge lamp recognizes that the lamp is abnormal. Lighting device. 6. The control means includes information transmission means for notifying an abnormality of the double tube discharge lamp to the outside when the double tube discharge lamp is recognized as abnormal.
5. The discharge lamp lighting device according to any one of items 4 to 4. 7. An apparatus main body having an opening; a discharge lamp lighting device according to any one of claims 1 to 6 provided in the apparatus main body; and an apparatus main body so as to be irradiated with light from a double tube discharge lamp. A display unit provided at the opening of the backlight unit.