JP4528761B2 - Light source device and display device - Google Patents

Description

  The present invention relates to a light source device and a display device, and more particularly to a light source device and a display device having a discharge tube that emits light by discharging in a rare gas.

  A backlight of a display device such as a liquid crystal display device uses a light source device including one or a plurality of discharge tubes and a reflector. The discharge tube is a cold cathode tube, mercury is sealed in Ar gas or Ne gas, and a fluorescent material is applied to the tube wall. Mercury gas generates ultraviolet light during discharge, and the ultraviolet light hits a fluorescent material to generate visible light (see Patent Documents 1 and 2).

  Many backlights of a liquid crystal display device include a light guide plate. In one example, two light source devices are arranged facing both sides of the light guide plate. Each light source device includes two discharge tubes and a reflector. In this arrangement, two discharge tubes having a diameter of several mm are arranged in a narrow region of 10 mm or less. Therefore, the temperature around the discharge tube is often 70 ° C. or higher. In particular, the temperature rises rapidly in the vicinity of the electrode of the discharge tube, and when the supply current is increased to increase the luminance, it may be 120 ° C. or higher.

  The light emission amount-temperature characteristic of the discharge tube tends to decrease the light emission amount in a high temperature range by the following mechanism. First, considering the probability that mercury gas emits ultraviolet rays, it is roughly proportional to mercury gas concentration and current. On the other hand, mercury gas also has the property of absorbing ultraviolet light, and its absorption rate changes exponentially with respect to the product of the mercury gas concentration and the distance that must be transmitted (as the concentration increases and the transmittance increases). As the distance that must be increased, the transmittance changes).

  Ultraviolet light is converted into visible light by a fluorescent material coated on the tube wall. The probability that one ultraviolet photon is incident on the fluorescent material is the product of the diameter of the discharge tube and the mercury gas concentration. In summary, the visible light emission amount I can be expressed as the tube diameter d, mercury gas concentration n (function of discharge tube temperature), and current J as follows.

I to k × (J × n) × exp (−b × n × d) (1)
(K and b are proportional constants)
Formula (1) has a property that I has a maximum value with respect to a predetermined mercury gas concentration n, and when the mercury gas concentration becomes higher than the predetermined concentration n, the amount of visible light emission decreases. Since the mercury gas concentration changes exponentially with the temperature of the mercury gas, the luminance decreases as the tube temperature increases in the high temperature range.

Further, since the tube temperature increases as the current increases, the amount of visible light emission decreases even when the current is increased under a constant environmental temperature. These reductions have been a problem in increasing the brightness of the backlight.
Japanese Patent Laid-Open No. 03-084846 JP 2000-251847 A

  In the light source device, the place where the temperature becomes highest when the discharge tube is turned on is electrodes provided at both ends of the discharge tube. For this reason, heat-conducting members (heat-conducting rubber caps) are provided at both end portions of the discharge tube, and both end portions at the highest temperature are cooled by fitting the heat-conducting members to reflectors.

  However, if there is play in the fitting between the heat conducting member (heat conducting rubber cap) and the discharge tube, the contact will be insufficient and it will not be possible to achieve a sufficient cooling effect, and the temperature in the vicinity of the electrode will be 130-140 ° C It will rise to the extent.

  Usually, the electrode terminal of the discharge tube and the harness wiring for feeding are soldered, and the soldering position is in the vicinity of or inside the heat conducting member. For this reason, there exists a possibility that a solder | melting may melt | dissolve at the said temperature, and the connection reliability of the electrode terminal of a discharge tube and harness wiring will fall.

  On the other hand, as a means for making the luminance uniform, it is conceivable to control the mercury gas concentration in the discharge tube to be uniform. Since the mercury gas concentration depends on the temperature of the discharge tube as described above, the mercury gas concentration is made uniform by locally cooling the discharge tube, thereby trying to stabilize the luminance. .

  Specifically, the mercury gas concentration at the position where the heat conducting member is disposed can be increased by arranging the heat conducting member having a heat radiation function in the discharge tube. For this reason, by arranging the heat conducting member in the discharge tube as appropriate and setting the temperature of the discharge tube at a temperature that gives the optimum concentration of mercury gas, the light emission amount can be maximized in the entire discharge tube.

  When the vicinity of the electrode is cooled and the vicinity of the electrode is excessively cooled in the light source device that performs such local cooling, the following problem occurs.

  In other words, in the light source device that has been cooled as described above, the temperature in the vicinity of the electrode may become the minimum temperature on the surface of the discharge tube by overcooling the electrode. In this case, the mechanism for controlling the mercury gas concentration becomes invalid. Specifically, when the temperature is equal to or lower than the internal temperature of the local cooling portion, the mercury gas concentration is highest near the electrode. When mercury collects in the vicinity of the electrode in this way, the mercury is consumed rapidly, causing a problem that the tube life of the discharge tube is reduced.

  On the other hand, local cooling at the position where the heat conducting member is disposed may not be sufficiently performed only by arranging the heat conducting member having a heat radiation function in the discharge tube. In this case, non-uniform luminance distribution occurs and mercury collects in the vicinity of the electrode as described above when the temperature at the electrode position is lower than the temperature at the position where the heat conducting member is disposed.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a light source device and a display device that can achieve high luminance and uniform luminance, and can also improve reliability.

  In order to solve the above-described problems, the present invention is characterized by the following measures.

The invention described in claim 1
A discharge tube configured to cause discharge between the electrodes disposed at both ends in the glass tube and to emit light using the discharge;
A reflector for reflecting the light emitted from the discharge tube;
A light source device that holds an end of the discharge tube and has a heat conduction holding member that cools the discharge tube at a holding position,
A sputter region where spatter adheres to the inside of the glass tube by the discharge is configured to be covered by the heat conducting holding member.

  According to the above invention, since the sputter region is covered with the heat conduction holding member, it is possible to prevent discharge from occurring between the sputter region and the reflector, and to improve the reliability of the light source device.

The invention according to claim 2
A light source device according to claim 1;
A display element illuminated by the light source device;
A light guide plate that receives light from the light source device and guides the incident light to the display element by a formed reflection layer;
Is characterized in that the enhanced formation density of the reflective layer in the sputtering region near the light source device.

  As described above, according to the light source device of the first aspect, it is possible to prevent discharge from occurring between the sputter region and the reflector, and to improve the reliability of the light source device. However, in this configuration, the sputter region, which is a part of the light emitting region of the discharge tube, is covered with the heat conduction holding member, so that there is a possibility that the luminance in the vicinity of the heat conduction holding member is lowered.

  However, by increasing the formation density of the reflective layer in the vicinity of the sputter region of the light source device, it is possible to increase the luminance in the vicinity of the heat conducting holding member, and uniformize the luminance of the illumination on the display element.

The invention according to claim 3
A light source device according to claim 1 ;
A display element illuminated by the light source device;
And have a holding unit for holding the display element,
The light source device further includes a central heat conducting member that locally cools the discharge tube by contacting the central portion of the discharge tube,
The holding unit and is characterized in that a heat radiating portion thermally connected to the heat-conducting member for the central portion for radiating heat of the heat-conducting member for the central portion.

According to the above invention, the holding unit for holding the display element is provided with the heat radiating portion, and the heat radiating portion contacts the central portion of the discharge tube to thermally connect it to the central portion heat conducting member that locally cools it. Since it was set as the structure which was made, the heat | fever of the center-part heat- conduction member is radiated | emitted via a thermal radiation part. As a result, the discharge tube can be efficiently locally cooled, and the luminance of the entire discharge tube can be stabilized.

The invention according to claim 4
The display device according to claim 3, wherein
Furthermore, an adjusting mechanism for adjusting the degree of heat conduction between the heat radiating portion and the central portion heat conducting member is provided.

According to the above invention, by providing the adjusting mechanism that adjusts the degree of heat conduction with the central heat conducting member, the heat radiation state of the central heat conducting member can be adjusted to an optimum state, and the discharge tube The brightness as a whole can be stabilized.

  As described above, according to the present invention, various effects described below can be realized.

  According to invention of Claim 1, it can prevent that discharge generate | occur | produces between a sputter | spatter area | region and a reflector, and can improve the reliability of a light source device.

  According to the second aspect of the present invention, it is possible to increase the luminance in the vicinity of the heat conducting holding member, and to uniform the luminance of the illumination on the display element.

  Further, according to the invention described in claim 3, it is possible to efficiently locally cool the discharge tube, and it is possible to stabilize the luminance of the entire discharge tube.

Further, according to the invention described in claim 4, it is possible to adjust the heat radiation state of the central portion heat conducting member to an optimum state, and the brightness of the entire discharge tube can be stabilized.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  1 to 3 show a light source device 30A according to a first embodiment of the present invention and a liquid crystal display unit 10 (display device) using the light source device 30A. First, the liquid crystal display unit 10 on which the light source device 30A is mounted will be described with reference to FIG. The liquid crystal display unit 10 generally includes a liquid crystal panel 11, a decorative plate 12, a light guide plate 14, a carriage frame 17, a back plate 18, a light source device 30A, and the like.

  The liquid crystal panel 11 is configured such that a driver 26 for driving the liquid crystal panel body 25 is disposed on the outer periphery of the liquid crystal panel body 25 on which characters, images, and the like are displayed. A decorative plate 12 is disposed on the liquid crystal panel 11.

  The decorative plate 12 is made of a metal material such as stainless steel (SUS), iron or aluminum, or a resin material, and is processed into a box-lid shape including a frame body portion 27 and an opening portion 28. The decorative plate 12 has a function of reinforcing the liquid crystal panel 11.

  The frame portion 27 is configured to face the driver 26 disposed in the liquid crystal panel body 25. The opening 28 is configured to face the liquid crystal panel body 25 of the liquid crystal panel 11.

  On the other hand, the carriage frame 17 is disposed below the liquid crystal panel 11. The carriage frame 17 is made of a resin molded product such as polycarbonate or a metal material such as SUS or aluminum and has a function of supporting the liquid crystal panel 11.

  The light source device 30A includes a discharge tube 31 (fluorescent tube), a reflector 45, and the like. The light source device 30 </ b> A is disposed to face the side surface of the light guide plate 14. The discharge tube 31 serves as a light source of the liquid crystal display unit 10 and is configured to be detachable from the reflector 45. For convenience of explanation, details of the light source device 30A will be described later.

  The light guide plate 14 is formed of a highly transparent resin such as acrylic. The light guide plate 14 is disposed to face the back surface of the liquid crystal panel 11. An optical sheet 15 is disposed on the surface side of the light guide plate 14 (side facing the liquid crystal panel 11).

  The optical sheet 15 condenses and diffuses light emitted from the light guide plate 14 and efficiently emits light to the liquid crystal panel 11. A reflection sheet 16 is disposed on the back side of the light guide plate 14. The reflection sheet 16 plays a role of reflecting light leaking from the light guide plate 14 and returning the light to the inside of the light guide plate 14 again.

  The back plate 18 accommodates the reflector 13, the light guide plate 14, the optical sheet 15, the reflection sheet 16, and the like. Similar to the carriage frame 17, the back plate 18 is formed of a resin molded product such as polycarbonate or a metal material such as SUS or aluminum.

  Next, 30 disposed in the liquid crystal display unit 10 having the above-described configuration will be described in detail with reference to FIGS. 1 and 2.

  As described above, the light source device 30A includes the discharge tube 31, the reflector 45, and the like. 1 and 2 show an enlarged view of the vicinity of one end of the discharge tube 31 provided in the light source device 30A.

  The discharge tube 31 is a cold cathode tube, mercury is sealed in Ar gas or Ne gas in a glass tube 42, and a fluorescent material is applied to the tube wall. Mercury gas generates ultraviolet rays during discharge, and the ultraviolet rays hit the fluorescent material to generate visible light. In this embodiment, two discharge tubes 31 having a diameter of about 3 mm are arranged in a narrow region of 10 mm or less.

  Electrodes 34 are provided at both ends of each discharge tube 31, and electrode terminals 33 connected to the electrodes 34 are drawn out from the glass tube 42 and joined to the metal plate 38A by solder 40. It is configured. The metal plate 38 </ b> A is configured such that the terminal portion 37 of the power supply harness wiring 36 is joined by the solder 40 in the same manner as the electrode terminal 33.

  As a result, power is supplied to each electrode 34 of the discharge tube 31 from the harness wiring 36 via the metal plate 38A. The harness wiring 36 is inserted into an insertion hole 39 formed at the bottom of the bottomed opening 35 </ b> A and drawn out of the harness wiring 36.

  Further, the light source device 30A according to the present embodiment is configured to make the mercury gas concentration in the discharge tube 31 uniform by performing local cooling, thereby achieving uniform luminance in the entire discharge tube 31. It is a thing. For this reason, in the light source device 30 </ b> A according to the present embodiment, the central portion heat conduction member 51 is attached at a substantially central position of the discharge tube 31.

  FIG. 7 shows the heat conducting member 51 for the central part, and FIG. 8 shows a state where the heat conducting member 51 for the central part is attached to the discharge tube 31. The central heat conducting member 51 is made of, for example, silicone rubber having a thermal conductivity of 0.3 W / m / K, and is configured such that a discharge tube mounting portion 52 and a discharge tube locking portion 53 are integrally formed.

  The discharge tube locking portion 53 is configured to be flexibly deformable by providing the slit 54, and thus has a configuration in which the attachment property of the discharge tube 31 is improved. The discharge tube locking portion 53 is configured such that a surface opposite to the discharge tube mounting portion 52 to which the discharge tube 31 is mounted is in contact with the reflector 45.

  Therefore, since the heat generated in the discharge tube 31 is radiated to the reflector 45 through the central heat conducting member 51, the discharge tube 31 can be locally cooled. In addition, as described above, the arrangement position of the heat conducting member 51 for the central portion of the discharge tube 31 is cooled, so that the concentration of mercury gas can be increased. Therefore, the mercury gas concentration in the discharge tube 31 can be made uniform by appropriately selecting the arrangement position of the central heat conducting member 51, and the brightness of the light generated in the discharge tube 31 is accordingly increased. Can be made uniform.

  The end portion of the discharge tube 31 configured as described above is configured to be held by the reflector 45 via the heat conducting member 32A. The reflector 45 is mainly formed of a metal material such as SUS, iron, or aluminum, and is disposed along the discharge tube 31. A silver vapor deposition layer or a white reflective layer is formed on the surface of the reflector 45 facing the discharge tube 31 so that light from the discharge tube 31 is efficiently reflected. Thereby, the light of the discharge tube 31 is efficiently guided to the light guide plate 14 without being dispersed.

  The heat conducting member 32A is made of, for example, silicone rubber having a thermal conductivity of 0.3 W / m / K, and has a bottomed opening 35 formed at the center thereof. The metal plate 38A and a part of the discharge tube 31 are mounted in the bottomed opening 35.

  At the time of mounting, the bottomed opening 35 is filled with the low thermal conductivity member 41A in advance. The low thermal conductivity member 41A functions as an adhesive, and a material having a thermal conductivity lower than that of the heat conducting member 32A (ie, less likely to conduct heat) is selected. Specifically, as the low thermal conductivity member 41A, a silicone-based room temperature curable (RTV) rubber (SE4486 manufactured by Toray Dow, white) or grease having an equivalent function can be used.

  The filling amount of the low thermal conductivity member 41A can be adjusted. Specifically, the filling amount that covers only the electrode terminal 33 in a state where the discharge tube 31 is mounted on the heat conducting member 32 is set as the minimum filling amount, and the interval between the minimum filling amount and the maximum filling amount that fills the bottomed opening 35 is obtained. The filling amount can be arbitrarily set with. In the present embodiment, as shown in FIG. 1, the filling amount of the low thermal conductivity member 41 </ b> A is set to a filling amount that covers part of the end portions of the electrode terminal 33 and the glass tube 42.

  By filling the bottomed opening 35 with the low thermal conductivity member 41A as described above, each discharge tube 31 is held by the heat conducting member 32A via the low thermal conductivity member 41A. At this time, in a region where the low thermal conductivity member 41A is not disposed, the discharge tube 31 and the heat conducting member 32A are separated (they are separated by an amount indicated by an arrow ΔH in FIG. 1).

  For this reason, in a region where the discharge tube 31 and the heat conducting member 32A are separated from each other, the amount of heat released from the discharge tube 31 to the heat conducting member 32A is small. On the other hand, in the region where the low thermal conductivity member 41A is interposed between the discharge tube 31 and the heat conducting member 32A, the amount of heat released from the discharge tube 31 to the heat conducting member 32A is equal to the thermal conductivity of the low thermal conductivity member 41A. In response, heat is released.

  Thus, according to the present embodiment, since the low thermal conductivity member 41A is disposed between the discharge tube 31 and the heat conducting member 32A, the degree of heat conduction from the discharge tube 31 to the heat conducting member 32A is reduced. It can be controlled by the conductivity member 41A. Since the low thermal conductivity member 41A has a lower thermal conductivity than the heat conducting member 32A as described above, the heat radiation efficiency of the discharge tube 31 can be reduced compared to the configuration in which the discharge tube 31 is in direct contact with the heat conducting member 32A. it can.

  Accordingly, it is possible to prevent the vicinity of the electrode 34 of the discharge tube 31 from being cooled too much, and it is possible to make the distribution of mercury gas in the discharge tube 31 uniform, and thus to make the luminance uniform over the entire discharge tube 31. be able to.

  Further, in this embodiment, when selecting the low thermal conductivity member 41A, the temperature of the electrode terminal 33 of the discharge tube 31 is changed to the melting temperature of the solder 40 (joining material) by being radiated (cooled) by the low thermal conductivity member 41A. A material having a thermal conductivity that can be maintained at a temperature that does not exceed is selected.

  By selecting the thermal conductivity of the low thermal conductivity member 41A in this way, the low thermal conductivity member 41A maintains the temperature of the electrode terminal 33 at a temperature lower than the solder melting temperature, so that the electrode terminal 33 is removed from the metal plate 38A. Separation can be prevented and connection reliability between the discharge tube 31 and the harness wiring 36 can be improved.

  Furthermore, in this embodiment, when the temperature at a portion (hereinafter referred to as an electrode position) in the vicinity of the position where the discharge tube 31 is in contact with the heat conducting member 32A is T1 (hereinafter referred to as an electrode temperature T1), this electrode Low thermal conductivity so that the electrode temperature T1 is higher (T1> T2) than the temperature T2 (hereinafter referred to as the low temperature portion T2) of the portion where the temperature of the discharge tube 31 is the lowest (hereinafter referred to as the low temperature portion) at a position other than the position. The thermal conductivity of the rate member 41A is selected.

  Specifically, as described with reference to FIGS. 7 and 8, the low temperature portion of the discharge tube 31 is a portion where the central portion heat conduction member 51 is disposed. Therefore, the thermal conductivity of the low thermal conductivity member 41A is selected so that the electrode temperature T1 is higher than the low temperature temperature T2. In the case of the present embodiment, since the heat conducting member 51 for the central portion and the heat conducting member 32A are the same material, the thermal conductivity of the low thermal conductivity member 41A is determined from the thermal conductivity of the heat conducting member 51 for the central portion and the heat conducting member 32A. Is set lower, the electrode temperature T1 can be made higher than the low temperature temperature T2.

  As described above, the concentration of mercury gas in the discharge tube 31 has a characteristic that it is high at a portion where the temperature is low and low at a portion where the temperature is high. Therefore, by adopting the above configuration, it is possible to prevent the gas concentration of mercury gas that contributes to light emission from increasing in the vicinity of the electrode 34, so that the luminance of light emitted from the discharge tube 31 can be stabilized.

  Next, a second embodiment of the present invention will be described.

  FIG. 4 shows a light source device 30B according to the second embodiment of the present invention. In FIG. 4, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof is omitted. The same applies to each embodiment described below.

  In the light source device 30B according to the present embodiment, instead of the low thermal conductivity member 41A used in the light source device 30A according to the first embodiment, a 130 mm 2 silicone oil compound (G750 manufactured by Toray Dow, thermal conductivity 1.5W). / K / m) is filled in the bottomed opening 35 as the low thermal conductivity member 41B.

  This silicone-based oil compound is a material having a lower viscosity than the silicone-based chamber RTV type rubber that is the material of the low thermal conductivity member 41A used in the first embodiment. Therefore, when the discharge tube 31 and the metal plate 38A are mounted in the bottomed opening 35, the end portions of the electrode terminal 33 and the electrode 34 can be easily inserted into the low thermal conductivity member 41B.

  Thereby, the discharge tube 31 can be easily mounted in the heat conducting member 32A, and workability can be improved. Further, unnecessary external force is not applied to the harness wiring 36 at the time of mounting, and disconnection of the harness wiring 36 can be prevented.

  Furthermore, since the low thermal conductivity member 41B has high fluidity, it is possible to improve contact with the discharge tube 31, the electrode terminal 33, the metal plate 38A, and the like. Note that the silicone-based chamber RTV type rubber is cured at room temperature by being allowed to stand. Therefore, after curing, the low thermal conductivity member 41B holds the discharge tube 31 and the like in the heat conducting member 32A.

  Next, a third embodiment of the present invention will be described.

  FIG. 5 is a diagram for explaining a light source device 30C according to the third embodiment of the present invention. The light source device 30C according to the present embodiment does not use the heat conducting member 32A used in the first and second embodiments, holds the discharge tube 31 on the reflector 45 by the first spacer 46A, and connects the harness wiring 36 to the second. The spacer 47A is held by the reflector 45, and a low thermal conductivity member 41C is filled between the first spacer 46A and the second spacer 47A.

  The first spacer 46A and the second spacer 47A are plate-like members formed by molding, for example, silicone resin. As shown in FIG. 5B, the first spacer 46A has two holding holes 48 into which the respective discharge tubes 31 are inserted and held. Further, as shown in FIG. 5C, the second spacer 47A is formed with a holding hole 50 into which the electrode terminal 33 is inserted and held, and an insertion hole 44 into which the terminal portion 37 is inserted.

  Positioning between the discharge tube 31 and the reflector 45 is performed by fitting the first spacer 46 </ b> A into the reflector 45. The second spacer 47A is also fitted in the reflector 45, whereby the harness wiring 36 is held by the reflector 45 via the second spacer 47A.

  The space formed between the first and second spacers 46A and 47A is filled with the low thermal conductivity member 41C using, for example, a dispenser. The low thermal conductivity member 41C functions as an adhesive, and for example, a silicone-based RTV rubber (SE4486 manufactured by Toray Dow, white) can be used.

  For the low thermal conductivity member 41, a material having a thermal conductivity lower than that of the reflector 45 (heat is hardly transmitted) is selected. Thereby, the heat conduction from the discharge tube 31 to the reflector 45 can be controlled by the low thermal conductivity member 41C.

  Since the low thermal conductivity member 41C has a lower thermal conductivity than the reflector 45, the heat radiation efficiency of the discharge tube 31 can be reduced as compared with the configuration in which the discharge tube 31 is in direct contact with the reflector 45. As a result, it is possible to prevent the vicinity of the electrode 34 of the discharge tube 31 from being cooled too much, and to make the distribution of mercury gas in the discharge tube 31 uniform, thereby achieving uniform brightness throughout the discharge tube 31. be able to.

  Further, in this embodiment, the electrode temperature T1 at the portion where the vicinity of the electrode 34 of the discharge tube 31 is in contact with the low thermal conductivity member 41C (hereinafter referred to as the electrode position) is higher than the low temperature portion temperature T2 of the low temperature portion ( The thermal conductivity of the low thermal conductivity member 41C is selected so that T1> T2). With this configuration, it is possible to prevent the gas concentration of mercury gas contributing to light emission from increasing in the vicinity of the electrode 34 for the same reason as described in the first embodiment. The brightness of the emitted light can be stabilized.

  Next, a fourth embodiment of the present invention will be described.

  FIG. 6 is a diagram for explaining a light source device 30D according to the fourth embodiment of the present invention. Similarly to the light source device 30C according to the third embodiment, the light source device 30D according to the present embodiment does not use the heat conducting member 32A used in the first and second embodiments, and the first and second spacers. The discharge tube 31 and the harness wiring 36 are held by 46B and 47B. Further, a low thermal conductivity member 41C is filled between the first spacer 46B and the second spacer 47B.

  Further, as shown in FIG. 6A, the first spacer 46B is not different from the first spacer 46A provided in the light source device 30C according to the third embodiment, but the holding position of the discharge tube 31 is not changed. Is disposed at a position shifted to the left side in the drawing (left end portion position in the drawing of the electrode 34) as shown in FIG. 6A as compared with the light source device 30C according to the third embodiment. On the other hand, since the second spacer 47B holds only the harness wiring 36, as shown in FIG. 6C, only one holding hole 49 is formed.

  Further, the low thermal conductivity member 41C is filled between the first spacer 46B and the second spacer 47B using a dispenser or the like as in the third embodiment. The material and characteristics of the low thermal conductivity member 41C are as described in the third embodiment. Compared to the light source device 30C according to the third embodiment, the light source device 30D according to the fourth embodiment described above is a low thermal conductivity member 41C in which a part of the harness wiring 36 (not the terminal portion 37) also functions as an adhesive. Can be fixed. For this reason, even if an external force such as pulling is applied to the harness wiring 36 in the right direction in FIG. 6A, the harness wiring 36 is fixed by the low thermal conductivity member 41C. It is possible to prevent separation.

  Here, paying attention to the structure in which the discharge tube 31 and the harness wiring 36 are electrically connected, description will be given below.

  FIG. 9 shows a connection structure between a general discharge tube 31 and the harness wiring 36. This connection structure is substantially the same as the connection structure used in the light source devices 30A to 30D according to the first to fourth embodiments. That is, in the connection structure shown in FIG. 9, a metal plate 38A having three holes 55 is prepared as shown in FIG. 9A, and the discharge tube 31 is placed in each hole 55 as shown in FIG. The electrode terminal 33 and the terminal part 37 of the harness wiring 36 are inserted. After that, the insertion positions of the electrode terminal 33 and the terminal portion 37 into the metal plate 38A are joined by the solder 56, whereby the terminal portion 37 is electrically connected to the electrode terminal 33 via the metal plate 38A.

  FIG. 10 shows a connection structure between another discharge tube 31 and the harness wiring 36. In this connection structure, the electrode terminal 33 of the discharge tube 31 is bent at a substantially right angle, and the bent portion is temporarily fixed by the metal coil 57. And solder 56 is arranged on the upper part of metal coil 57 temporarily fixed, and, thereby, electrode terminal 33 and terminal part 37 are electrically connected.

  However, in the above connection structure, if the temperature of the connection portion where the solder 56 is disposed rises to about 120 ° C. close to the solder melting temperature due to deterioration over time or the like, long-term reliability due to insufficient strength of the solder 56 (joint portion) or a creep phenomenon. Insufficiency occurs. The solder creep phenomenon means a phenomenon in which when the soldered portion is left at a high temperature, the solder 56 becomes non-uniform, recrystallization proceeds, the strength of the boundary between the crystals decreases, and the fracture occurs.

  FIG. 11 shows a connection structure between the discharge tube 31 and the harness wiring 36 devised therefor. The connection structure shown in the figure is a structure for connecting the discharge tube 31 and the harness wiring 36 without using the solder 56. That is, a caulking fitting 58 is used instead of the solder 56, and the discharge tube 31 and the harness wiring 36 are mechanically connected by the caulking fitting 58.

  In the connection structure shown in FIG. 11A, the terminal portion 37 (bundle of copper thin wires) of the harness wiring 36 is bifurcated, and each terminal portion 37 and the electrode terminal 33 are fixed by caulking metal fittings 58. It is a thing. In the connection structure shown in FIG. 11B, the two lead wires 59 are caulked and fixed to the terminal portion 37 of the harness wiring 36 by the caulking metal fittings 58, and the lead wires 59 are caulked to the electrode terminals 33. It is fixed by caulking.

  Further, in the connection structure shown in FIG. 11C, the electrode terminal 33 of one discharge tube 31 and one end of the lead wire 59 are caulked and fixed to the terminal portion 37 of the harness wiring 36 by the caulking metal fitting 58. The other end portion is caulked and fixed to the electrode terminal 33 of the other discharge tube 31 by a caulking metal fitting 58. As described above, in the configuration in which the caulking metal fitting 58 is used for connection, the electrode terminal 33 and the terminal portion 37 are mechanically connected. Therefore, even when the environmental temperature rises, the joining occurs when the solder 56 is used. There is no reduction in strength.

  However, the connection structure shown in FIGS. 10 and 11 also has a problem that the distance between the pair of discharge tubes 31 cannot be made constant (in the connection structure of FIG. 10, the problem caused by the solder 56). Also occurs).

  That is, in the connection structure shown in FIG. 9, since the electrode terminal 33 is inserted into the hole 55 of the metal plate 38A, the position of the electrode terminal 33 (that is, the position of the discharge tube 31) is the formation of the hole 55 in the metal plate 38A. Positioned by position. Therefore, in the connection structure shown in FIG. 9, the distance L between the pair of discharge tubes 31 is constant.

  On the other hand, in the connection structure shown in FIGS. 10 and 11, the separation distance L between the pair of discharge tubes 31 varies depending on the amount of overlap in the metal coil 57 of the bent portion of the electrode terminal 33. In the connection structure shown in FIG. 11, the distance L between the pair of discharge tubes 31 varies as the terminal portion 37 and the lead wire 59 are deformed.

  As described above, since the discharge tube 31 is normally disposed in a narrow region of 10 mm or less, the separation distance L between the pair of discharge tubes 31 is constant and needs to be set as narrow as possible. On the other hand, when the separation distance L between the discharge tubes 31 varies as described above, there is a problem that the reflector 45 and the discharge tube 31 come into contact with each other. Furthermore, the space required for connection becomes large, and there is a problem that it becomes difficult to incorporate it in a light source device that is recently desired to be small and thin.

  Next, a fifth embodiment of the present invention will be described.

  FIG. 12 is a view for explaining a light source device 30E according to the fifth embodiment of the present invention. The embodiments described below with reference to FIGS. 12 to 22 are intended to solve the problems that occur on the connection structure connecting the electrode terminal 33 and the terminal portion 37 described above.

  The light source device 30E according to the fifth embodiment has a pair of discharge tubes 31, and the electrode terminals 33 provided on the discharge tubes 31 are connected to the terminal portions 37 of the harness wiring 36 together. The present embodiment is characterized in that an unfolded metal plate 60A shown in FIG. 12B is used to connect the discharge tube 31 and the harness wiring 36 to each other. In addition, what is shown with a broken line in the same figure has shown the bending position.

  The metal plate 60A has a configuration in which a first caulking portion 61A, a second caulking portion 62A, and a base portion 63A are integrally formed. The pair of discharge tubes 31 are arranged in parallel to the metal plate 60A. Only the electrode terminal 33 of one discharge tube 31 is caulked and fixed to the first caulking portion 61A, and the electrode terminal 33 of the other discharge tube 31 and the terminal portion 37 of the harness wiring 36 are secured to the second caulking portion 62A. Are fixed together by caulking.

  Further, a pair of positioning holes 64 are formed in the base 63A that connects the first caulking portion 61A and the second caulking portion 62A. The positioning hole 64 is for inserting the electrode terminal 33 of the discharge tube 31.

  FIG. 13 is a diagram for explaining a method of caulking the second caulking portion 62A formed on the metal plate 60A. As shown in the figure, a mold 65 is used to caulk the second caulking portion 62A (metal plate 60A). The mold 65 includes an upper mold 66 and a lower mold 67. The upper mold 66 has a curved mold section 68, and the lower mold 67 has a hollow mold section 69 on which the electrode terminal 33 and the terminal section 37 are mounted. Is formed.

  In order to perform the caulking process, first, as shown in FIG. 13A, after the electrode terminal 33 and the terminal part 37 are mounted on the mold part 69, the second caulking process is performed between the upper mold 66 and the lower mold 67. The part 62A (metal plate 60A) is interposed. Then, the upper die 66 is pressed (pressed) against the lower die 67. Accordingly, as shown in FIG. 13B, the electrode terminal 33 and the terminal portion 37 are caulked and fixed to the second caulking portion 62A, and mechanically and electrically connected.

  In FIG. 13, only the portion for caulking the second caulking portion 62A of the metal plate 60A is shown, but the processing for caulking and fixing the electrode terminal 33 of the other discharge tube 31 to the first caulking portion 61A is also the second. Caulking and fixing are performed collectively on the caulking portion 62A. Thus, by performing the caulking process of the first and second caulking portions 61A and 62A collectively, the caulking process can be made more efficient.

  Thus, each discharge tube 31 of the discharge tube 31 and the terminal portion 37 of the harness wiring 36 are fixed to the respective crimping portions 61A and 62A of the metal plate 60A by caulking, which is a mechanical process. For this reason, the bonding strength of the discharge tube 31 and the terminal portion 37 and the caulking portions 61A and 62A is strong, so that the discharge tube 31 and the terminal portion 37 are not detached from the metal plate 60A even if the environmental temperature rises. In addition, the reliability of the light source device 30E can be improved.

  The formation positions of the caulking portions 61A and 62A formed on the metal plate 60A correspond to the positions of the electrode terminals 33 of the discharge tubes 31 arranged in parallel to the predetermined positions. For this reason, by caulking the discharge tube 31 to the metal plate 60A, the position of each discharge tube 31 is positioned by the metal plate 60A. In particular, in the configuration of this embodiment, since the positioning hole 64 is formed in the base portion 63A, the discharge tube 31 can be positioned with higher accuracy by inserting the electrode terminal 33 into the positioning hole 64. it can. Thereby, the space | interval L of a pair of discharge tube 31 is ensured with high precision, and the connection of the electrode terminal 33 and the terminal part 37 can be performed in a space-saving.

  Further, in this embodiment, the electrode terminal 33 of one discharge tube 31 and the terminal portion 37 of the harness wiring 36 are collectively caulked by the second caulking portion 62A. Thereby, compared with the structure which crimps the discharge tube 31 and the terminal part 37 separately, the total number of crimping parts can be reduced and size reduction of the metal plate 60A and the light source device 30E can be achieved.

  FIG. 14 is a diagram for explaining a light source device 30F according to the sixth embodiment.

  In this embodiment, the developed metal plate 60B shown in FIG. 14B is used to connect the discharge tube 31 and the harness wiring 36 (note that the broken line in FIG. Indicates the folding position).

  The metal plate 60B has a first caulking portion 61B and a second caulking portion 62B as in the fifth embodiment. Each of the caulking portions 61B and 62B is bent at a substantially right angle with respect to the base portion 63B. For this reason, by using the metal plate 60B according to the present embodiment, the area of the metal plate 60B after caulking can be reduced, and the light source device 30F can be downsized.

  FIG. 15 is a diagram for explaining a light source device 30G according to the seventh embodiment.

  The present embodiment is characterized in that the unfolded metal plate 60C shown in FIG. 15B is used to connect the discharge tube 31 and the harness wiring 36 (note that in FIG. Indicates the folding position).

  The metal plate 60C has the first caulking portion 61B and the second caulking portion 62B as in the fifth embodiment, and the shape of the base portion 63C that continues the caulking portions 61B and 62B is substantially Z-shaped. It is characterized by. With this configuration, the caulking portions 61B and 62B are displaced from each other in the horizontal direction and the vertical direction in FIG. 15B, so that the two caulking portions 61B and 62B can be caulked simultaneously on the same plane. It becomes. For this reason, the caulking process can be simplified.

  FIG. 16 is a diagram for explaining a light source device 30H according to the eighth embodiment.

  In this embodiment, the developed metal plate 60D shown in FIG. 16B is used to connect the discharge tube 31 and the harness wiring 36 (note that in FIG. Indicates the folding position).

  The metal plate 60D of the present embodiment is characterized in that a first caulking portion 61D for caulking the discharge tube 31 and a second caulking portion 62D for caulking the terminal portion 37 of the harness wiring 36 are provided separately. Is. With this configuration, since the electrode terminal 33 and the terminal portion 37 can be fixed by different caulking portions 61D and 62D, the connection strength can be improved.

FIG. 17 is a diagram for explaining a light source device 30I according to the ninth embodiment.
In this embodiment, the base 63E is elastically deformed by forming a slit 70 in the base 63E that connects the first caulking portion 61E and the second caulking portion 62E. is there.

Thus, by making the base 63E located between the caulking portions 61E and the caulking portions 62E of the metal plate 60E into elastically deformable portions that can be elastically deformed, the discharge tube 31, the harness wiring 36, or the metal plate 60E after the caulking process. Even when an external force is applied, the external force can be absorbed by the base 63E being elastically deformed. Thereby, it can prevent that the discharge tube 31 grade | etc., Is damaged by external force, and can improve the reliability of the light source device 30I.
In the above-described embodiment, the base 63E is configured to be elastically deformable by providing the slit 70. However, the base 63E is made elastic by other methods such as forming a hole or reducing the thickness. It is good also as composition to do.

  FIG. 18 is a diagram for explaining a light source device 30J according to the tenth embodiment.

  In this embodiment, the distance between the end of the glass tube 42 of the discharge tube 31 and the metal plate 60E (indicated by the arrow D in the figure) is at least a distance greater than the diameter of the electrode terminal 33. It is characterized by.

FIG. 19 shows the relationship between the separation distance (horizontal axis) between the end of the glass tube 42 and the metal plate 60E and the incidence (vertical axis) of occurrence of cracks in the glass tube 42, as implemented by the present inventors. ing. As shown in the figure, when the end of the glass tube 42 is in contact with the metal plate 60E, the crack occurrence rate is a high value of about 28%.
As the distance between the end of the glass tube 42 and the metal plate 60E increases, the crack generation rate gradually decreases, and the distance between the end of the glass tube 42 and the metal plate 60E becomes the diameter of the electrode terminal 33. At that point, the crack generation rate becomes zero. This is because when the distance between the end of the glass tube 42 and the metal plate 60E increases, the amount of elastic deformation at this portion (that is, the electrode terminal 33) increases, and external force can be absorbed. It depends.

  Therefore, by setting the distance between the end of the glass tube 42 and the metal plate 60E to be equal to or larger than the diameter of the electrode terminal 33, it is possible to prevent the discharge tube 31 from cracking. However, even if the separation distance between the end of the glass tube 42 and the metal plate 60E is increased, the light source device 30J only increases in size. For this reason, in reality, it is desirable to set the distance between the end of the glass tube 42 and the metal plate 60 </ b> E substantially equal to the diameter of the electrode terminal 33.

FIG. 20 is a diagram for explaining the details of the metal plate 60F used in the light source device 30J according to the tenth embodiment.
The metal plate 60F according to the present embodiment also includes a first caulking portion 61F and a second caulking portion 62F, as shown in FIG. The first caulking portion 61F and the second caulking portion 62F are integrally connected by a base portion 63F. FIG. 20B is a view of the caulked metal plate 60 </ b> F viewed from the axial direction of the electrode terminal 33. As shown in the figure, the electrode terminal 33 is caulked and fixed to the first caulking portion 61F, and the electrode terminal 33 and the terminal portion 37 are caulked and fixed by the second caulking portion 62F.

  FIG. 20C shows the metal plate 60F before the caulking process. The metal plate 60F is made of brass (brass) or white made by adding nickel to brass from the viewpoint of shape stability, corrosion resistance, and low cost.

  The metal plate 60F has recesses 71 formed on both sides of the base 63F. And it is the structure which the extension part 72 extended toward the diagonally upward direction from the both sides of this hollow part 71 in the figure. When the caulking process is performed, the recessed portion 71 is provided with the electrode terminal 33 and the terminal portion 37.

  Specifically, when connecting the discharge tube 31 and the harness wiring 36 using the metal plate 60 </ b> F, first, the electrode terminal 33 is positioned and mounted in one recess 71, and the electrode terminal 33 is mounted in the other recess 71. And the terminal portion 37 are positioned and mounted simultaneously. Subsequently, each extending portion 72 is caulked using the mold 65 as described above with reference to FIG. 13, and the first caulking portion 61F and the second caulking portion 62F are collectively formed.

  That is, the first and second caulking portions 61F and 62F are collectively caulked. Thereby, the electrode terminal 33 and the terminal part 37 can be easily and reliably caulked to a predetermined position on the metal plate 60F. Further, when the electrode terminals 33 are attached to the respective recessed portions 71, the adjacent spacing pitch of the discharge tube 31 is determined by the spacing pitch between the pair of recessed portions 71. Therefore, the separation pitch of the discharge tubes 31 can be determined with high accuracy.

  On the other hand, as shown in FIG. 20C, the shape of the pair of indentations 71A and 71B provided in the metal plate 60G may be different. In the present embodiment, a recess 71B corresponding to the second crimping portion 62F in which the electrode terminal 33 and the terminal portion 37 are crimped is provided to the recess 71A corresponding to the first crimping portion 61F in which only the electrode terminal 33 is crimped. The configuration is large.

  Thus, the caulking portions 61F and 62F corresponding to the indented portions 71A and 71B are appropriately changed by changing the sizes of the indented portions 71A and 71B according to the number of the electrode terminals 33 and the terminal portions 37 mounted inside. Even if they are caulked together, they can be securely caulked and fixed, and it is possible to prevent the electrode terminal 33 or the terminal portion 37 from protruding or detached from the caulking portions 61F and 62F.

FIG. 21 is a diagram for explaining the light source device according to the eleventh embodiment.
In this embodiment, the electrode terminals 33A and 33B of the two discharge tubes 31 are bent at a substantially right angle, and the electrode terminals 33A and 33B are caulked at the same time as the terminal portions 37 of the harness wiring 36 with a metal plate 60H. is there. By adopting this configuration, it is possible to reduce the cost by reducing the size of the metal plate 60H and to perform connection by a single caulking process, thereby simplifying the caulking process and reducing the number of steps.

  FIG. 22 shows a modification of the light source device shown in FIG. In this modification, the electrode terminals 33A and 33B of the discharge tube 31 are bent in a crank shape, and the electrode terminals 33A and 33B and the terminal portions 37 of the harness wiring 36 are caulked simultaneously with the metal plate 60H, thereby realizing the connection. By adopting this configuration, it is possible to reduce the cost by reducing the size of the metal plate 60H and to perform connection by one caulking process, thereby simplifying the caulking process and reducing the number of steps.

  Next, a twelfth embodiment of the present invention will be described.

  FIG. 23 shows an enlarged view of the vicinity of the heat conducting member 32B of the light source device 30K according to the twelfth embodiment (this heat conducting member 32B corresponds to the heat conducting holding member recited in the claims). As described above, the electrode 34 is disposed at the end of the discharge tube 31, and the vicinity of the electrode 34 is held by the heat conducting member 32B. The electrode 34 is connected to the harness wiring 36.

  FIG. 24 shows an enlarged view of the vicinity of the holding portion 32C (corresponding to the heat conducting member 32B) of the conventional light source device as a comparative example. Conventionally, the local cooling described above is not performed, and the holding portion 32C is provided only for holding the discharge tube 31. As described above, since the holding portion 32C is conventionally intended to be held, the holding portion 32C is made small to such an extent that the incident efficiency from the discharge tube 31 to the light guide plate 14 (see FIG. 3) is not lowered (the electrode is not completely covered). It was.

  However, when the discharge tube 31 reaches the end of its life, spatter is deposited on the inner wall of the glass tube within 1 mm to 2 mm from the end of the light emitting portion of the electrode 34 (hereinafter, the region where the sputter is deposited is referred to as a sputter region 75). When the sputter region 75 is deposited on the end of the light emitting portion of the electrode 34 as described above, a current flows through the sputter and generates heat. In particular, when the voltage is high, a discharge phenomenon occurs between the sputter region 75 and the reflector 45. There is a case. When this discharge occurs, the luminance distribution of the light source device becomes non-uniform, and the life of the discharge tube 31 is significantly reduced.

  Therefore, in this embodiment, as shown in FIG. 23, the sputter region 75 where spatter adheres to the inside of the glass tube by discharge is configured to be covered with the heat conducting member 32B. Specifically, the heat conducting member 32 </ b> B is configured to cover a portion of 1 mm or more from the light emitting portion side end of the electrode 34.

  As described above, the heat conducting member 32B is an electrical insulating material such as silicone rubber. Therefore, by covering the sputter region 75 with the heat conducting member 32B, it is possible to prevent a discharge from occurring between the sputter region 75 and the reflector 45, and to improve the reliability of the light source device 30D.

  However, when the heat conducting member 32B is enlarged, a part of the light emitting region of the discharge tube 31 is also covered with the heat conducting member 32B. For this reason, it is considered that the shadow of the heat conducting member 32 </ b> B enters the incident surface of the light guide plate 14. In this case, a phenomenon occurs in which the vicinity of both end portions of the discharge tube 31 becomes dark.

  Therefore, in the present embodiment, a high density region 76 in which the area density of the dot pattern or line pattern is increased is formed on the reflection sheet 16 disposed on the light guide plate 14, and this high density region 76 is in the vicinity of the sputter region 75, in other words. In this case, the discharge tube 31 is arranged in the vicinity of both end portions. Thereby, since the reflectance of the reflective sheet 16 increases in the vicinity of the sputter region 75 of the light source device 30K, it is possible to increase the luminance in the vicinity of the heat conducting member 32B. For this reason, the brightness | luminance of illumination can be equalized over the whole light source device 30K.

  Next, a thirteenth embodiment of the present invention will be described.

  25 and 26 show a liquid crystal display device 80 according to the thirteenth embodiment. FIG. 25 is an exploded perspective view of the liquid crystal display device 80, and FIG. 26 is an enlarged perspective view of the main part. The liquid crystal display device 80 includes the liquid crystal display unit 10, a front cover 81, a rear cover 82, a holding unit 83, and the like.

  The liquid crystal display unit 10 has a configuration equivalent to that described above with reference to FIG. 3, and light source devices 30 </ b> L are disposed on both upper and lower sides thereof. The light source device 30L is configured to perform the above-described local cooling. Therefore, as shown in FIG. 26, a central portion heat conducting member 51 is disposed at a predetermined position of the discharge tube 31.

  The liquid crystal display unit 10 is fixed to the holding unit 83. The holding unit 83 is configured to include a holding plate 84 and a tilt mechanism 85. The holding plate 84 is formed by molding a metal plate such as aluminum or a steel plate, and has a high thermal conductivity (easy to conduct heat). Further, the tilt mechanism 85 tilts the holding plate 84, and is configured so that the liquid crystal panel 11 can be adjusted to an easy-to-view angle. The liquid crystal display device 80 is configured such that a holding unit 83 to which the liquid crystal display unit 10 is fixed is covered with a front cover 81 and a rear cover 82.

  By the way, as described above, in this embodiment, the local cooling is performed. For this reason, the central portion heat conducting member 51 is provided at a predetermined position of the discharge tube 31. As shown in FIG. 8, the central portion heat conducting member 51 is engaged with the discharge tube 31, and is configured to radiate the heat of the discharge tube 31 to the reflector 45. The heat conducted to the reflector 45 is radiated to the outside through the back plate 18 of the liquid crystal display unit 10.

  However, the arrangement position of the heat conducting member 51 for the central portion is usually the back of the liquid crystal display unit 10 and is a position where heat dissipation is difficult. For this reason, even if the heat conductive member 51 for the central part is provided, there is a case where heat cannot be efficiently radiated from the heat conductive member 51 for the central part, and in this case, the luminance of the light source device 30L is also uneven. .

  Therefore, in this embodiment, the holding plate 84 of the holding unit 83 is provided with a heat radiating portion 87A that is thermally connected to the central heat conducting member 51. In the present embodiment, the heat radiating portion 87A is provided in a portion corresponding to the position where the central portion heat conducting member 51 of the holding plate 84 is disposed. The heat radiating portion 87 </ b> A has a configuration in which the holding plate 84 is collectively formed by pressing and bent toward the liquid crystal display unit 10. For this reason, the heat radiation part 87A can be easily formed.

  When the liquid crystal display unit 10 is mounted on the holding unit 83, the heat dissipating portion 87A having the above-described configuration is provided on the back surface (the back surface of the back plate 18) of the central portion heat conducting member 51 as shown in FIG. It is comprised so that it may contact | abut. As a result, the heat generated in the discharge tube 31 is transmitted to the heat conducting member 51 for the central portion, and then transferred to the back plate 18 via the reflector 45.

  Furthermore, since the heat radiating portion 87A is in contact with the back plate 18 located on the back surface of the center portion heat conducting member 51, the center portion heat conducting member 51 is thereby connected to the holding unit 83 via the reflector 45 and the back plate 18. The configuration is such that the holding plate 84 is thermally connected. Therefore, the heat generated in the discharge tube 31 is efficiently dissipated, whereby the discharge tube 31 can be efficiently cooled locally, and the luminance of the discharge tube 31 as a whole can be stabilized.

  FIG. 27 shows a first modification of the liquid crystal display device 80 according to the thirteenth embodiment. In this modification, a knob 88 is provided in the heat radiating portion 87B, and the knob 88 is configured to be movable in the directions of arrows X1 and X2 in the drawing along a guide groove 89 formed in the holding plate 84. It is. One surface of the heat radiating portion 87 </ b> B is in sliding contact with the back plate 18, and the other surface (the surface on which the knob 88 is formed) is in sliding contact with the holding plate 84.

  Specifically, by sliding the knob 88 in the direction of the arrow X2 in the drawing, the heat radiating portion 87B approaches the position where the central portion heat conducting member 51 is disposed. Conversely, by sliding the knob 88 in the direction of the arrow X1 in the figure, the heat radiating portion 87B is separated from the position where the central heat conducting member 51 is disposed. The back plate 18 and the holding plate 84 are configured to be thermally connected only by the heat radiating portion 87B. Therefore, by sliding the knob 88 in the direction of the arrow X2 in the figure, it is possible to increase the amount of heat released from the heat conducting member 51 for the central portion, and conversely, by sliding the knob 88 in the direction of the arrow X1 in the figure, The amount of heat released from the center portion heat conducting member 51 can be reduced.

  As described above, since the distribution of mercury gas in the discharge tube 31 depends on the temperature of the discharge tube 31, the mercury gas distribution (that is, the luminance distribution) is adjusted by adjusting the cooling degree of the discharge tube 31. Can be adjusted. Therefore, the heat radiating portion 87B functions as an adjustment mechanism that adjusts the degree of heat conduction of the central heat conducting member 51, so that the heat radiating state of the central heat conducting member 51 can be adjusted to an optimum state. The brightness of the entire tube can be stabilized.

  FIG. 28 shows a second modification of the liquid crystal display device 80 according to the thirteenth embodiment. In this modification, an opening 90 is formed at the back surface position of the heat conducting member 32B of the back plate 18, and the terminal portion 37A is directly brought into contact with the heat conducting member 32B, thereby increasing the heat radiation efficiency of the heat conducting member 32B. is there.

  As in the present modification, the part that enhances the heat radiation characteristics by the heat radiation part 87A is not limited to the position where the central heat conduction member 51 is disposed, but cools the heat conduction members 32B located at both end positions of the light source device 30L. It is good also as a structure. Moreover, in order to perform local cooling efficiently, it is also possible to cool the part where the heat conducting member 32B and the central heat conducting member 51 are not disposed by the heat radiating part 87A.

FIG. 1 is an enlarged sectional view showing the vicinity of an electrode of a discharge tube of a light source apparatus according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view showing an enlarged vicinity of the electrode of the discharge tube of the light source apparatus according to the first embodiment of the present invention. FIG. 3 is an exploded perspective view showing a liquid crystal display unit using the light source device according to the first embodiment of the present invention. FIG. 4 is an enlarged sectional view showing the vicinity of the electrode of the discharge tube of the light source apparatus according to the second embodiment of the present invention. FIG. 5 is a diagram for explaining a light source device according to a third embodiment of the present invention. FIG. 6 is a diagram for explaining a light source device according to a fourth embodiment of the present invention. FIG. 7 is a perspective view of the central heat conducting member used to explain local cooling of the discharge tube. FIG. 8 is a perspective view showing a state in which the central heat conducting member is mounted on the discharge tube. FIG. 9 is a diagram for explaining a connection structure between a general discharge tube and harness wiring (part 1). FIG. 10 is a diagram for explaining a connection structure between a general discharge tube and harness wiring (part 2). FIG. 11 is a diagram for explaining a connection structure between a general discharge tube and harness wiring (part 3). 12A and 12B show a light source device according to a fifth embodiment of the present invention, in which FIG. 12A is an enlarged perspective view showing a main part in the vicinity of a metal plate, and FIG. 12B shows a state in which the metal plate is developed. FIG. FIG. 13 is a diagram for explaining a method of manufacturing the light source device shown in FIG. 14A and 14B show a light source device according to a sixth embodiment of the present invention, in which FIG. 14A is an enlarged perspective view showing a main part in the vicinity of the metal plate, and FIG. 14B is a state in which the metal plate is developed. FIG. FIG. 15 shows a light source device according to a seventh embodiment of the present invention, in which (A) is an enlarged plan view showing a main part near the metal plate, and (B) is a state in which the metal plate is developed. FIG. FIG. 16 shows a light source device according to an eighth embodiment of the present invention, in which (A) is an enlarged plan view showing a main part in the vicinity of the metal plate, and (B) is a state in which the metal plate is developed. FIG. FIG. 17 is an enlarged plan view showing a main part in the vicinity of the metal plate of the light source device according to the ninth embodiment of the present invention. FIG. 18 is an enlarged plan view showing a main part in the vicinity of the metal plate of the light source device according to the tenth embodiment of the present invention. FIG. 19 is a diagram for explaining the effect of the light source device according to the tenth embodiment of the present invention. FIG. 20 is a diagram for explaining in more detail a metal plate used in the light source device according to the tenth embodiment of the present invention. FIG. 21 is an enlarged plan view showing a main part in the vicinity of the metal plate of the light source device according to the eleventh embodiment of the present invention. FIG. 22 is an enlarged plan view showing a main part in the vicinity of a metal plate of a light source device which is a modification of the eleventh embodiment. FIG. 23 is an enlarged perspective view showing a main part in the vicinity of the heat conducting member of the light source apparatus according to the twelfth embodiment of the present invention. FIG. 24 is a perspective view showing a light source device as a comparative example of the light source device according to the twelfth embodiment of the present invention. FIG. 25 is an exploded perspective view showing a liquid crystal display device according to the thirteenth embodiment of the present invention. FIG. 26 is an enlarged view showing a main part of the liquid crystal display device shown in FIG. FIG. 27 is a diagram for explaining a first modification of the liquid crystal display device shown in FIG. FIG. 28 is a diagram for explaining a second modification of the liquid crystal display device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal display unit 11 Liquid crystal panel 14 Light guide plate 16 Reflective sheet 18 Back surface board 30A-30L Light source device 31 Discharge tube 32A-32C Heat conduction member 33 Electrode terminal 34 Electrode 36 Harness wiring 37 Terminal part 38A Metal plate 41A-41C Low heat conductivity member 45 reflectors 46A, 46B first spacers 47A, 47B second spacers 48-50 holding holes 51 central portion heat conducting members 60A-60H metal plates 61A-61F first caulking parts 62A-62F second caulking parts 63A- 63F Base 64 Positioning hole 65 Mold 70 Slit 71, 71A, 71B Recessed portion 72, 72A, 72B Extension portion 75 Spatter region 76 High density region 80 Liquid crystal display device 81 Front cover 82 Rear cover 83 Holding unit 84 Holding plates 87A, 87B Radiator 88 Knob 89 Guide groove 90 Aperture

Claims (4)

A discharge tube configured to cause discharge between the electrodes disposed at both ends in the glass tube and to emit light using the discharge;
A reflector for reflecting the light emitted from the discharge tube;
A light source device that holds an end of the discharge tube and has a heat conduction holding member that cools the discharge tube at a holding position,
A light source device characterized in that a sputter region where spatter adheres to the inside of the glass tube by the discharge is covered with the heat conducting holding member. A light source device according to claim 1;
A display element illuminated by the light source device;
A light guide plate that receives light from the light source device and guides the incident light to the display element by a formed reflection layer;
Display device characterized by having an increased formation density of the reflective layer in the sputtering region near the light source device. A light source device according to claim 1 ;
A display element illuminated by the light source device;
And have a holding unit for holding the display element,
The light source device further includes a central heat conducting member that locally cools the discharge tube by contacting the central portion of the discharge tube,
Wherein the holding unit, display device characterized by having a heat radiating portion thermally connected to the heat-conducting member for the central portion for radiating heat of the heat-conducting member for the central portion. The display device according to claim 3, wherein
The display device further includes an adjustment mechanism for adjusting a degree of heat conduction between the heat radiating portion and the heat conducting member for the central portion .

Images