JPH08659U - Backlight device - Google Patents

Abstract

(57) [Summary] (Modified) [Configuration] Fluorescent tube 1 for generating light, reflector 25 for reflecting light generated by the fluorescent tube, function as a starting electrode for starting the fluorescent tube, and heat dissipation function And a heat dissipation plate disposed opposite to the fluorescent tube, and a heat dissipation plate disposed opposite to the fluorescent tube. [Effect] Since the metallic body having high thermal conductivity as the starting electrode is arranged on the reflector side, the starting performance of the fluorescent tube can be improved without impairing the heat dissipation effect, and the heat generation of the fluorescent tube is made uniform. it can.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a backlight system such as a liquid crystal panel and a slide using a fluorescent tube.

[0002]

[Prior art]

 In the conventional back light system, the relative distance between the fluorescent tube and the metal body as the starting electrode is set to be as close as possible to each other. However, in the conventional backlight system, as the tube length of the fluorescent tube becomes longer, capacitive coupling occurs between the glass surface of the fluorescent tube and the metal body as the starting electrode, and as a result, the fluorescent tube at low temperature is The startability was poor. An example of a conventional back light system will be described below with reference to the drawings. FIG. 3 shows a perspective view of a conventional back light system. 4 shows a cross-sectional view of FIG. Reference numeral 101 is a fluorescent tube, and terminal electrodes 102 are provided at both ends of the tube. The terminal electrode 102 is soldered to the fluorescent tube holding substrate 104. Reference numeral 105 denotes a reflector, which is formed of a metal member having high thermal conductivity and is electrically connected to the circuit system ground. As shown in FIG. 4, the fluorescent tube 101 and the reflection plate 105, that is, the metal body having high thermal conductivity are arranged close to each other. In order to improve the heat dissipation performance of the fluorescent tube 101, the fluorescent tube 101 and the reflecting plate 105 need to be as close as possible.

[0003]

[Problems to be solved by the device]

 However, the above back light system has the following problems.

Since the fluorescent tube 101 and the reflecting plate 105 are arranged close to each other in order to improve the heat radiation performance, capacitive coupling occurs between the tube surface of the fluorescent tube 101 and the reflecting plate 105, and as a result, the fluorescent tube 101 is applied. The voltage generated was divided and the startability at low temperature was degraded. Hereinafter, a detailed description will be given with reference to the backlight circuit diagram of FIG. In FIG. 5, 110 is a fluorescent tube, 111 is a back light lance, 112 is a high withstand voltage capacitor, and 113 is a reflector which also serves as a starting electrode. Here, when the fluorescent tube and the starting electrode are brought close to each other, the capacitance represented by the following equation is coupled as the stray capacitance C. Here, the distance between the tube surface of the fluorescent tube 110 and the reflecting plate 113 that also serves as the starting electrode is d = 0.5 mm, the permittivity of air is εr = 1, and the area where the fluorescent tube 110 and the reflecting plate 113 face each other is S = With 900 mm ² ,

[0005]

[Table 1]

That is, the stray capacitance C = 16 PF is coupled. Assuming that the output voltage of the back light lance 111 is 3000 V _PP, if the stray capacitance C is not present at all, a voltage of 3000 V _PP will be applied to the fluorescent tube 110 at startup. However, when the floating capacitance C is coupled, the voltage applied to the fluorescent tube at the time of starting is divided by the floating capacitance C and the high breakdown voltage capacitor 112 and becomes as follows.

[0007]

[Table 2]

That is, although the output voltage of the backlight lance 111 is 3000 V _PP , the voltage actually applied to the fluorescent tube is 2127 V _PP . Here, if the distance d between the tube surface of the fluorescent tube 110 and the reflecting plate 113 that also serves as the starting electrode is increased, the stray capacitance C is decreased and the voltage applied to the fluorescent tube can be increased. However, if the distance d is increased, the heat dissipation performance deteriorates, and the performance as the starting electrode also deteriorates. The back light system of the present invention solves the above problems, and an object thereof is to provide a back light system having good startability and good heat dissipation.

[0009]

[Means for Solving the Problems]

 The backlight system of the present invention includes a fluorescent tube that emits light, a reflector that reflects the light generated by the fluorescent tube, and a heat sink that has a function as a starting electrode that starts the fluorescent tube and a heat sink. The reflecting plate is arranged to face the fluorescent tube, and the heat radiating plate is arranged to face the fluorescent tube.

[0010]

【Example】

 FIG. 1 shows a perspective view of an embodiment of the present invention. Reference numeral 1 is a fluorescent tube provided with a fluorescent tube terminal 2. The fluorescent tube terminal 2 is soldered to the fluorescent tube holding substrate 4. Reference numeral 5 denotes a reflecting plate, which is formed of a metal part having high thermal conductivity and is connected to the ground potential on the fluorescent tube holding substrate 4. The reflector 5 is provided with a diaphragm 6 along the fluorescent tube 1 so that the distance between the tube surface of the fluorescent tube 1 and the reflector 5 is partially changed. FIG. 2 shows a sectional view of FIG. On the implementation side, capacitive coupling occurs between the fluorescent tube 1 and the diaphragm 6 as in the conventional case, but capacitive coupling is less likely to occur in other portions because the fluorescent tube 1 and the reflector 5 are separated from each other. Has become. In other words, if the shape of the narrowed portion 6 is determined according to the shape of the fluorescent tube 1 and the combination of the characteristics of the starting electrode and the stray capacitance coupling state, the heat dissipation effect of the fluorescent tube 1 is not impaired and the startability is improved. Can be improved. Further, according to the present embodiment, since the narrowed portions 6 are provided at both ends of the portion near the fluorescent tube end 2 where the heat generation amount is large, heat dissipation from the portion near the fluorescent tube terminal 2 is promoted. The heat generation of the fluorescent tube 1 can be made uniform. Further, in the present embodiment, the distance between the fluorescent tube 1 and the reflection plate 5 is partially changed by drawing, but this may be done by cutting and bending.

FIG. 6 shows a perspective view of another embodiment of the present invention. Reference numeral 1 is a fluorescent tube provided with a fluorescent tube terminal 2. The fluorescent tube terminal 2 is soldered to the fluorescent tube holding substrate 4. Reference numeral 25 is a reflector, which is made of plastic and has a reflective surface that is subjected to aluminum vapor deposition. Reference numeral 26 is a radiator plate, which is made of a metal having a high thermal conductivity, such as aluminum. A hole 27 is partially formed in the reflecting plate 25 in accordance with the shape of the fluorescent tube 1, and a heat radiating plate 26 is incorporated in the hole 27 and is arranged close to the fluorescent tube 1. Further, the heat dissipation plate 26 is connected to the ground potential on the fluorescent tube holding substrate 4. Also in this embodiment, if the disposition position of the heat dissipation plate 26 is optimally set in consideration of the characteristics as the starting electrode and the coupling state of the floating capacitance, the starting performance can be improved. Further, in this embodiment, the heat radiation amount as a whole is reduced as compared with the previous embodiment, but since the reflection plate 25 is made of plastic, there is a degree of freedom in the shape of the reflection surface. . There is an advantage that the heat generation of the fluorescent tube 1 can be made uniform by setting the shape according to the heat generation distribution of the fluorescent tube 1.

[0012]

[Effect of device]

 As explained above, in the backlight system of the present invention, the metal body having a high heat conductivity as the starting electrode is arranged on the reflector side, so that the heat dissipation effect is not impaired and the fluorescent tube is not damaged. The startability can be improved. Further, the heat generation of the fluorescent tube can be made uniform.

[Submission date] May 29, 1995

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

[Industrial applications]

The present invention relates to a backlight device such as a liquid crystal panel and a slide using a fluorescent tube.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

[Prior art]

 Conventional back lightapparatus, The relative distance between the fluorescent tube and the metal body as the starting electrode was set as close as possible to each other. However, conventional back light apparatus In the above, as the tube length of the fluorescent tube becomes longer, capacitive coupling occurs between the glass surface of the fluorescent tube and the metal body serving as the starting electrode, and as a result, the starting ability of the fluorescent tube at low temperature deteriorates. Referring to the drawings below, a conventional back lightapparatusAn example will be described. Figure 3 shows the conventional back light.apparatusThe perspective view which shows is shown. 4 shows a sectional view of FIG. Reference numeral 101 is a fluorescent tube, and terminal electrodes 102 are provided at both ends of the tube. The terminal electrode 102 is soldered to the fluorescent tube holding substrate 104. Reference numeral 105 denotes a reflector, which is formed of a metal member having high thermal conductivity and is electrically connected to the circuit system ground. As shown in FIG. 4, the fluorescent tube 101 and the reflecting plate 105, that is, the metal body having high heat conductivity are arranged in proximity to each other. In order to improve the heat dissipation performance of the fluorescent tube 101, it is necessary that the fluorescent tube 101 and the reflection plate 105 are as close as possible.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

[Problems to be solved by the device]

However, the above back light device has the following problems.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

That is, the stray capacitance C = 16PF is coupled. Assuming that the output voltage of the back light lance 111 is 3000 V _PP, if the stray capacitance C is not present at all, a voltage of 3000 V _PP will be applied to the fluorescent tube 110 at startup. However, when the floating capacitance C is coupled, the voltage applied to the fluorescent tube at the time of starting is divided by the floating capacitance C and the high breakdown voltage capacitor 112 and becomes as follows.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

That is, although the output voltage of the backlight lance 111 is 3000 V _PP , the voltage actually applied to the fluorescent tube is 2127 V _PP . Here, if the distance d between the tube surface of the fluorescent tube 110 and the reflecting plate 113 that also serves as the starting electrode is increased, the stray capacitance C is decreased and the voltage applied to the fluorescent tube can be increased. However, if the distance d is increased, the heat dissipation performance deteriorates, and the performance as the starting electrode also deteriorates. The back light device of the present invention solves the above problems, and an object thereof is to provide a back light device having good startability and good heat dissipation.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

[Means for Solving the Problems]

The backlight device of the present invention comprises a fluorescent tube that emits light, a reflector that reflects the light generated by the fluorescent tube, and a heat sink that has a function as a starting electrode for starting the fluorescent tube and a heat dissipation function. In addition, the reflecting plate is arranged to face the fluorescent tube, and the heat radiating plate is arranged to face the fluorescent tube.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

【Example】

FIG. 1 shows a perspective view of a reference example of the present invention. Reference numeral 1 is a fluorescent tube, and a fluorescent tube terminal 2 is provided. The fluorescent tube terminal 2 is soldered to the fluorescent tube holding substrate 4. Reference numeral 5 denotes a reflecting plate, which is formed of a metal part having a high thermal conductivity and is connected to the ground potential on the fluorescent tube holding substrate 4. The reflector 5 is provided with a diaphragm 6 along the fluorescent tube 1 so that the distance between the tube surface of the fluorescent tube 1 and the reflector 5 is partially changed. FIG. 2 shows a sectional view of FIG. On the implementation side, capacitive coupling occurs between the fluorescent tube 1 and the diaphragm 6 as in the conventional case, but capacitive coupling is less likely to occur at other portions because the distance between the fluorescent tube 1 and the reflector 5 is large. Has become. In other words, if the shape of the narrowed portion 6 is determined according to the shape of the fluorescent tube 1 and the combination of the characteristics as the starting electrode and the stray capacitance coupling state, the heat dissipation effect of the fluorescent tube 1 is not impaired and the startability is improved. Can also be improved. Further, according to the present embodiment, since the narrowed portions 6 are provided at both ends of the fluorescent tube end 2 near the fluorescent tube end 2 where heat generation is large, heat dissipation from the portion near the fluorescent tube terminal 2 is promoted. The heat generation of No. 1 can be made uniform. Further, in the present embodiment, the distance between the fluorescent tube 1 and the reflection plate 5 is partially changed by drawing, but this may be performed by cutting and bending.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

FIG. 6 shows a perspective view of an embodiment of the present invention . Reference numeral 1 is a fluorescent tube provided with a fluorescent tube terminal 2. The fluorescent tube terminal 2 is soldered to the fluorescent tube holding substrate 4. Reference numeral 25 is a reflecting plate made of plastic, and the reflecting surface is subjected to aluminum vapor deposition treatment. Reference numeral 26 is a radiator plate, which is made of a metal having a high thermal conductivity, such as aluminum. A hole 27 is partially formed in the reflecting plate 25 in accordance with the shape of the fluorescent tube 1, and a heat radiating plate 26 is incorporated in the hole 27 and is arranged close to the fluorescent tube 1. Further, the heat dissipation plate 26 is connected to the ground potential on the fluorescent tube holding substrate 4. Also in the present embodiment, the startability can be improved if the arrangement position of the heat dissipation plate 26 is optimally set in consideration of the characteristics as the starting electrode and the coupling state of the stray capacitance. Further, in the present embodiment, since it is formed by the reflector 25 Gapu plastics, there is a degree of freedom in the counter-reflecting surface shape. By setting the shape according to the heat generation distribution of the fluorescent tube 1, there is an advantage that the heat generation of the fluorescent tube 1 can be made uniform.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

[Effect of device]

 As explained above, the back light of the present invention is used.apparatusIs a thermally conductive starting electrode Since the high heat dissipation plate is arranged on the reflector side, The starting performance of the fluorescent tube can be improved without impairing the heat dissipation effect. Further, it is possible to make the heat generation of the fluorescent tube uniform.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a perspective view showing a conventional back light system.

FIG. 4 is a sectional view of FIG.

FIG. 5 is a back light circuit diagram.

FIG. 6 is a perspective view of another embodiment of the present invention.

[Explanation of symbols]

 1, 101, 110 ... Fluorescent tube 2, 102 ... Fluorescent tube terminal 4, 104 ... Fluorescent tube holding substrate 5, 105, 25 ... Reflector 6 ...・ ・ ・ Throttle part 26 ・ ・ ・ ・ ・ ・ ・ ・ Radiation plate 27 ・ ・ ・ ・ ・ ・ Hole 112 ・ ・ ・ ・ ・ ・ High-voltage container 113 ・ ・ ・ ・・ Reflector that doubles as a starting electrode

[Procedure amendment]

[Submission date] May 29, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Name of device

[Correction method] Change

[Correction content]

[Title of device ] Backlight device

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Scope of utility model registration request

[Correction method] Change

[Correction content]

[Scope of utility model registration request]

[Procedure Amendment 12]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a perspective view of a reference example of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a perspective view showing a conventional back light device .

FIG. 4 is a sectional view of FIG.

FIG. 5 is a back light circuit diagram.

FIG. 6 is a perspective view of an embodiment of the present invention .

[Explanation of reference symbols] 1, 101, 110 ... Fluorescent tube 2, 102 ... Fluorescent tube terminal 4, 104 ... Fluorescent tube holding substrate 5, 105, 25 ... Reflector plate 6・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Throttle part 26 ・ ・ ・ ・ ・ ・ ・ ・ Radiation plate 27 ・ ・ ・ ・ ・ ・ ・ Hole 112 ・ ・ ・ ・ ・ ・ High-voltage condenser 113 ・ ・.... Reflector that doubles as a starting electrode

Claims (1)

[Scope of utility model registration request] 1. A fluorescent tube that emits light, a reflector that reflects the light generated by the fluorescent tube, and a heat sink that has a function as a starting electrode for starting the fluorescent tube and a heat sink function. The backlight system is characterized in that the reflection plate is arranged facing the fluorescent tube, and the heat dissipation plate is arranged facing the fluorescent tube.