JP2009266509A - Illuminating device and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminating device capable of eliminating luminance unevenness between end sides and the center of a hot-cathode lamp, alleviating the degradation of peripheral members caused by the heat of filaments, and also simplifying lamp wiring. <P>SOLUTION: The device is composed of a light-emitting glass tube 1a whose glass tube 1 has a function for illumination, and auxiliary glass tubes 1b continuously fitted at both ends of the light-emitting glass tube 1a nearly in a vertical direction with respect to the axial direction of the light-emitting glass tube 1a , and also having a role of illumination. In each auxiliary glass tube 1b, a filament 2 and lead wires 3 connected to both ends of the filament 2 are arranged, and at the outside of each auxiliary glass tube 1b, the auxiliary glass tube 1b of the hot-cathode lamp La equipped with a base 5 having pins 4 connected to the lead wires 3 penetrates a through-hole 7 of a case 9, and goes astride the inside and the outside of the case 9 with its bottom as a boundary of the case 9 in a state that each base 5 and a power-feeding socket 10 on a circuit board K1, K2 are connected to have hot-cathode lamps La fixed in the case 9. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an illumination device including a hot cathode lamp, and a liquid crystal display device including the illumination device as a backlight unit.

  Backlight units for liquid crystal display devices include a direct type system in which a plurality of discharge lamps, for example, cold cathode lamps, are stored in a casing, and a liquid crystal display panel disposed on the front surface of the casing is directly irradiated from the discharge lamps. .

  In recent years, liquid crystal display devices having a size of more than 50 inches to 100 inches have been put on the market in accordance with the need for larger liquid crystal display devices. However, the tube diameter of a cold cathode lamp generally used in a liquid crystal television is 3 mm to 4 mm, which has a small tube diameter, and there is a problem in strength. Further, since the tube diameter is small, the phosphor is uniformly coated inside the glass tube. Since coating technology is required, the 65 inch class (cold cathode lamp length is about 1500 mm) is considered the limit. Furthermore, since a cold cathode lamp has a small amount of power that can be supplied per lamp, when a liquid crystal display device tries to obtain a desired brightness, a considerable number of lamps are required (about 30 lamps are required for 65 inches). There is also the problem that the voltage is very high (about 2 kV at 65 inches).

  Accordingly, hot cathode lamps have recently attracted attention as backlights for large liquid crystal display devices. The hot cathode lamp has a merit that the number of lamps can be reduced because the electric power that can be supplied per lamp is large, and that the lamp voltage is 1/10 or less that of the cold cathode lamp due to arc discharge.

  Next, the structure of a backlight unit using a hot cathode lamp will be described with reference to the drawings. FIG. 15 is a configuration diagram of a backlight unit using hot cathode lamps, and includes a plurality of hot cathode lamps La and a housing 9 for storing these hot cathode lamps La. Here, the hot cathode lamp La is provided with a filament at both ends of a glass tube. The backlight unit BL is disposed on the back side of a liquid crystal panel (not shown), and includes a reflector 8, a side cover 14, a mounting frame 15, an optical sheet 20, a lighting device (not shown: generally the backlight unit BL). Arranged on the back side). In general, the optical sheet 20 is formed by laminating a diffusion plate 21, a diffusion sheet 22, and a lens sheet 23 in order from the back side. With the above configuration, light from the plurality of hot cathode lamps La lit by the lighting device is diffused when passing through the diffusion plate 21 and is emitted as averaged parallel light from the entire surface of the diffusion sheet 22.

Further, FIG. 16 shows a cross-sectional view of FIG. 15, and the hot cathode lamp La is turned on by a lighting circuit on the circuit board K. Further, two high-voltage wirings 41 and two low-voltage wirings 51 are necessary. One is a wiring for supplying lamp power and the other is a wiring for supplying preheating power for the filament. The hot cathode lamp La is fixed in the housing 9 by the lamp holder 16.
Japanese Patent No. 3149077 Japanese Patent No. 3816465

  Next, problems of a backlight unit using a hot cathode lamp will be described.

(Problem 1: Brightness unevenness)
In general, the luminance of the end portion side of the hot cathode lamp is lower than the luminance of the central portion, which causes luminance unevenness in the backlight unit.

(Problem 2: Deterioration of peripheral members due to filament heat)
In order to ensure the filament life of the hot cathode lamp, it is necessary to keep the filament temperature optimal. Specifically, power is supplied to the filament, and the filament spot temperature is designed to be about 800 ° C to 1000 ° C. Since the filament temperature is very high as described above, the glass tube wall temperature in the vicinity of the filament is 100 ° C. or higher due to the distance between the filament and the glass tube, and the heat of peripheral members such as the optical sheet 20 and the liquid crystal panel 30 It causes deterioration.

  Therefore, as shown in FIG. 16, a resin side cover 14 or the like is generally provided so as to cover the filament. However, as the area increases, the cost increases, and the backlight unit becomes narrower. It cannot be realized.

(Problem 3: Complicated lamp wiring)
As shown in FIG. 16, the wiring from the lighting circuit on the circuit board to the hot cathode lamp requires a total of two wires, one for supplying lamp power and one for supplying preheating power, for one filament. In one hot cathode lamp having a pair of filaments, a total of four wires, that is, a high voltage wire 41 and a low voltage wire 51 are required. In the case of a large-sized liquid crystal display device, since a plurality of hot cathode lamps are used, the wiring from these lighting circuits to the hot cathode lamps is very large, which causes problems such as complicated wiring and high assembly costs. Arise.

  As means for solving the luminance unevenness of Problem 1, Patent Document 1 (Patent No. 3149077) and Patent Document 2 (Patent No. 3816465) are disclosed.

  FIG. 17 is an explanatory diagram of Patent Document 1 (Japanese Patent No. 3149077). In this conventional example, the lead-out line 3 of the filament 2 is taken out from the side surface 1d of the fluorescent lamp La, and the end of the fluorescent lamp La is bent by bending the support portion of the filament 2 close to the end side of the fluorescent lamp La. This is a structure for improving the luminance of the part. However, when this fluorescent lamp is used for a backlight unit, it is surely effective for luminance unevenness (Problem 1), but since the filament 2 is located on the central axis of the fluorescent lamp La, the filament 2 The deterioration of the peripheral member due to the heat (Problem 2) is not solved.

  An explanatory view of Patent Document 2 (Japanese Patent No. 3816465) is shown in FIG. In this conventional example, as shown in FIG. 18, the filament 2 is provided in the auxiliary glass tube portion 1b without providing the filament 2 in the lighting glass tube portion 1a, and the connecting pipe line portion 1c and the auxiliary glass tube portion 1b are made of resin. By covering and concealing with a cover material 18 such as the above, blackening of the end of the glass tube portion 1a for illumination is eliminated, and a fluorescent lamp with good appearance is provided. However, since the connection pipe line part 1c and the auxiliary glass pipe part 1b are covered with the cover material 18, all the light emission from the connection pipe line part 1c and the auxiliary glass pipe part 1b is blocked. Moreover, in the center part of the glass tube part 1a for illumination, since there is no obstruction, it has a lighting function in all directions with respect to the circumference of the glass tube, but the glass tube part 1a for illumination with which the cover material 18 contacts or approaches. However, there is a problem that the illumination function with respect to the direction in which the cover member 18 is disposed is significantly reduced.

  That is, in the backlight unit, the light emitted forward (in the direction of the optical sheet) from the fluorescent lamp is used, but the light emitted backward (in the direction of the housing 9) is also reflected by the reflecting material 8 and used. For this reason, the brightness near the cover member 18 decreases, resulting in uneven brightness of the backlight unit.

  The present invention has been made in view of the above-described points, eliminates uneven brightness between the end side and the center of the hot cathode lamp, reduces deterioration of peripheral members due to the heat of the filament, and also provides lamp wiring. It is an object to provide a lighting device that can be simplified.

  As shown in FIGS. 1 to 6, the illuminating device of claim 1 includes a light emitting glass tube portion 1 a having a glass tube 1 function as illumination, and light emitting glass tube portions 1 a at both ends of the light emitting glass tube portion 1 a. The auxiliary glass tube portion 1b is provided continuously in a direction substantially perpendicular to the axial direction and also has a function as illumination. Inside the auxiliary glass tube portion 1b, the filament 2 and both ends of the filament 2 are provided. A lead-in wire 3 to be connected is arranged, and a hot-cathode lamp La having a base 5 having a pin 4 connected to the lead-in wire 3 outside the auxiliary glass tube portion 1b, and a plurality of through-holes 7 at the bottom. Provided with a reflector 8 on the inner surface, the front surface is open, and a box-shaped housing 9 in which the hot cathode lamp La is accommodated, and a power supply socket 10 for obtaining connection with the base 5. Mounted toward the back side of the housing 9 And circuit boards K1 and K2, which are fixed substantially parallel to the rear surface of the housing 9 at an arbitrary distance at the position where the through-hole 7 is disposed on the rear surface of the housing 9, and assist the hot cathode lamp La. With the glass tube portion 1b passing through the through-hole 7 of the housing 9 and straddling the inside and outside of the housing 9 with the bottom of the housing 9 as a boundary, the base 5 and the circuit boards K1, K2 The hot cathode lamp La is fixed in the housing 9 by connecting the upper power supply socket 10.

  As shown in FIGS. 7 to 10, the lighting device according to claim 2 is the end of the light emitting glass tube portion 1 a, in the invention according to claim 1, wherein the plurality of hot cathode lamps each having the light emitting glass tube portion 1 a are substantially straight. A plurality of hot cathode lamp groups arranged side by side in the axial direction are arranged in the axial direction so that the directions of the auxiliary glass tube portions 1b are aligned in a state where the parts are close to or in contact with each other. Are arranged in parallel to each other.

  As shown in FIGS. 11 and 12, the lighting device of claim 3 includes the two hot-cathode lamps according to the invention of claim 1, wherein the light emitting glass tube portion 1 a is substantially U-shaped or substantially U-shaped. In the state where both ends of the light emitting glass tube portion 1a of each hot cathode lamp are close to or in contact with each other, the auxiliary glass tube portions 1b are arranged side by side in the axial direction so as to be aligned. The group of the hot cathode lamps is arranged in parallel in the housing 9.

  As shown in FIG. 13, the illumination device according to claim 4 is the invention according to claims 1 to 3, wherein the filament 2 and the lead-in wire 3 arranged inside the auxiliary glass tube portion 1 b are arranged outside the housing 9. It is characterized by that.

  According to a fifth aspect of the present invention, in the invention of any one of the first to fourth aspects, a lighting circuit for lighting a hot cathode lamp is mounted on the circuit board in addition to the power supply socket. .

  As shown in FIG. 14, the lighting device according to claim 6 is the invention according to claims 1 to 5, wherein the insulating member 13 is provided between the housing 9 and the auxiliary glass tube portion 1 b in the through-hole 7 of the housing 9. It is characterized by the arrangement.

  A liquid crystal display device according to a seventh aspect includes the illumination device according to any one of the first to sixth aspects.

  In the lighting device according to claim 1, a filament having a plurality of through-holes at the bottom is continuously provided at both ends of the light emitting glass tube portion substantially perpendicularly to the axial direction of the light emitting glass tube portion. Since the hot cathode lamp provided with the arranged auxiliary glass tube portion is arranged, it is bright up to the end with respect to the axial direction where the hot cathode lamp is arranged, and there is an effect of suppressing luminance unevenness. In the present lighting device, the auxiliary glass tube portion also has an illumination function, and the auxiliary glass tube portion in the housing emits light, so that the luminance of the portion where the auxiliary glass tube portion is provided does not significantly decrease. Furthermore, since the high-temperature filament is not disposed in the light emitting glass tube portion, but is disposed in the auxiliary glass tube portion, and further, the auxiliary glass tube portion is disposed across the inside and outside of the housing with the bottom of the housing as a boundary, The filament moves away from the optical sheet and the liquid crystal panel, and thermal deterioration can be prevented. Further, since the base outside the auxiliary glass tube part is connected to the power supply socket mounted on the circuit board on the back side of the housing, the hot cathode lamp and the circuit board are directly connected, and the circuit board and the hot cathode lamp are connected. This wiring is unnecessary, and the complicated wiring unique to the hot cathode lamp can be eliminated. Furthermore, as described above, the hot cathode lamp is fixed to the circuit board through the power supply socket, so that the lamp holder in the casing for fixing the normal lamp is not necessary, luminance unevenness due to the influence of the lamp holder, mercury aggregation This problem can be solved.

  In the illumination device according to claim 2, the plurality of hot-cathode lamps, each having a light-emitting glass tube portion that is substantially straight, are arranged side by side in an axial direction in a state where the end portions of the light-emitting glass tube portion are close to or in contact with each other, Since a group of a plurality of hot cathode lamps arranged side by side is arranged in parallel in the housing, the front surface on which the optical sheet and the liquid crystal panel are arranged is irradiated while ensuring continuity of illumination in the axial direction. It is possible to partially control the illuminance of light with respect to the axial direction and the parallel direction.

  In the illumination device according to claim 3, the two hot cathode lamps each having a substantially U-shaped or substantially U-shaped light-emitting glass tube portion are adjacent to or in contact with both end portions of the light-emitting glass tube portion of each hot-cathode lamp. In this state, the two hot cathode lamp groups arranged in the axial direction are arranged in parallel in the housing, so that the front surface on which the optical sheet and the liquid crystal panel are arranged is irradiated. In addition to being able to partially control the illuminance of the emitted light in the axial direction and the parallel direction, only one circuit board is required to connect and fix the hot cathode lamp.

  The illumination device according to claim 4 has the filament and the lead-in wire arranged inside the auxiliary glass tube portion outside the housing, and therefore the filament as a high-temperature heat source, the optical sheet and the liquid crystal panel. Compared to the illumination device 1, it can be further away, and the effect of preventing thermal degradation is great. Moreover, since the temperature in a housing | casing can be lowered | hung, the efficiency of a hot cathode lamp can be improved.

  In the lighting device according to claim 5, since a lighting circuit for lighting the hot cathode lamp is mounted on the circuit board in addition to the power feeding socket, a circuit board for mounting the power feeding socket and a circuit board for mounting the lighting circuit There is no need to separate them.

  In the illumination device according to claim 6, since the insulating member is disposed between the housing and the auxiliary glass tube portion at the through-hole of the housing, the auxiliary glass tube portion can be prevented from being damaged by vibration and impact, and the housing And insulation of the hot cathode lamp.

  The liquid crystal display device according to a seventh aspect includes the effects of the illumination device according to the first to sixth aspects.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
The illumination device according to the present embodiment will be described with reference to FIG. 2. A housing 9 and two circuit boards K1 and K2 disposed on the back side of the housing 9 are provided.

  Here, as shown in FIG. 1, in the hot cathode lamps La1 to La4, a phosphor 6 is applied to the inner wall surface of the glass tube 1, and a straight light emitting glass tube portion 1a having an illumination function, and a light emitting glass tube portion 1a. The auxiliary glass tube portions 1b are provided at both ends of the glass tube portion 1b so as to be continuously provided substantially perpendicular to the axial direction of the light emitting glass tube portion 1a. In addition, the auxiliary glass tube portion 1b is coated with a phosphor 6 on the inner wall surface, the filament 2 is disposed toward the light emitting glass tube portion 1a, and an introduction line 3 connected to both ends of the filament 2 is disposed. Has been. Further, the auxiliary glass tube portion 1b has a base 5 provided with a pin 4 connected to the lead-in wire 3 at the end opposite to the side continuous with the light emitting glass tube portion 1a. .

  As described above, since the filament 2 is provided in the auxiliary glass tube portion 1b, the light emitting glass tube portion 1a is bright up to the end portion, and the whole has a lighting function. The auxiliary glass tube portion 1b has a lower brightness than the light emitting glass tube portion 1a, but has an illumination function. In particular, the portion closer to the light emitting glass tube portion 1a than the filament 2 is more than the filament 2. The brightness is higher than that of the portion close to the base 5.

  Next, the housing 9 for housing the hot cathode lamps La1 to La4 will be described with reference to FIG. The housing 9 used in this embodiment has a box-like shape with an open front, a rectangular bottom, and four through-holes 7 near both ends of the bottom in the X-axis direction (lamp longitudinal direction). And a total of eight through-holes 7 are provided at the bottom of the housing 9. The housing 9 used here is basically made of metal from the viewpoint of strength, but it may be made of a lightweight resin or the like. Further, a reflective material 8 for reflecting the light of the hot cathode lamps La1 to La4 to the front surface of the housing 9 is provided on the inner surface of the housing 9.

  Next, the two circuit boards K1 and K2 disposed on the back side of the housing 9 will be described with reference to FIG. The circuit boards K1 and K2 used in this embodiment have four power supply sockets 10 for connecting to the caps 5 of the hot cathode lamps La1 to La4, and lighting for lighting the plurality of hot cathode lamps La1 to La4. The circuit is implemented. However, it is assumed that there is an electrical connection such as a ground line between the circuit boards K1 and K2. Further, a circuit board for mounting the power supply socket 10 and a circuit board for mounting the lighting circuit may be separately provided and electrically connected to each other. The material of the circuit board used here is, for example, paper phenol or glass epoxy. The power supply socket 10 may be made of resin or metal.

  The present embodiment is a lighting device formed by using the hot cathode lamps La1 to La4, the casing 9, and the circuit boards K1 and K2 described above, and the combination of them is shown in FIG. The hot-cathode lamps La1 to La4 are arranged in parallel in the casing 9, and the casing 9 is at an arbitrary distance at positions where the through holes 7 are arranged on the back sides of both ends of the casing 9. The circuit boards K1 and K2 are fixed substantially parallel to the back surface of the circuit board.

  Subsequently, a more detailed description of the illumination device of the present embodiment is a cross-sectional view taken along the dotted line A in the X-axis direction in FIG. 2 (FIG. 5), and a cross-sectional view taken along the dotted line B in the Y-axis direction ( 6).

  As shown in FIG. 5, the circuit boards K <b> 1 and K <b> 2 are fixed to the back side of both ends of the housing 9 at an arbitrary distance from the back surface of the housing 9 by a fixing rod 11 (the fixing method is not necessarily limited to the fixing rod 11). Not) Further, in the hot cathode lamps La1 to La4, the auxiliary glass tube portions 1b at both ends penetrate the through-hole 7 of the housing 9, and straddle the inside and outside of the housing 9 with the bottom of the housing 9 as a boundary. Thus, the power supply socket 10 on the circuit boards K1 and K2 is connected via the base 5 outside the auxiliary glass tube portion 1b. That is, the hot cathode lamps La1 to La4 and the lighting circuits on the circuit boards K1 and K2 are connected without wiring, though the power supply socket 10 is interposed therebetween. Since the circuit boards K1 and K2 and the hot cathode lamps La1 to La4 are fixed as described above, the light emitting glass tube portion 1a of the hot cathode lamps La1 to La4 is naturally at an arbitrary distance from the bottom of the housing 9. It will be positioned in the housing 9.

  Next, the positional relationship between the filament 2 and the housing 9 of the hot cathode lamps La1 to La4 of this embodiment will be described with reference to FIG. As described above, the filament 2 is disposed in the auxiliary glass tube portion 1b straddling the bottom of the housing 9, but the filament 2 is substantially flush with the bottom of the housing 9 or on the circuit boards K1, K2. It is desirable to be arranged on the side. One reason for adopting the positional relationship is that the luminance of the auxiliary glass tube portion 1b in the housing 9 is not lowered. Since the luminance of the auxiliary glass tube portion 1b decreases as it approaches the filament 2, when the filament 2 is disposed on the auxiliary glass tube portion 1b in the housing 9, the luminance of the portion decreases and causes luminance unevenness. . Another reason is that the thermal degradation of the optical sheet 20 and the liquid crystal panel 30 is prevented by moving the filament 2 that is a high-temperature heat source away from the optical sheet 20 and the liquid crystal panel 30 disposed on the front surface of the housing 9. It is to do.

  From the above description, the illumination apparatus of the present embodiment has the auxiliary glass tube in which the filament 2 is arranged at both ends of the light emitting glass tube portion 1a continuously and substantially perpendicular to the axial direction of the light emitting glass tube portion 1a. Since the hot cathode lamps La1 to La4 provided with the portion 1b are arranged in the housing 9 having a plurality of through-holes 7 at the bottom, end portions with respect to the axial direction in which the hot cathode lamps La1 to La4 are arranged It is bright and has the effect of suppressing uneven brightness.

  Moreover, since this auxiliary | assistant glass tube part 1b also has an illumination function and the auxiliary | assistant glass tube part 1b in the housing | casing 9 light-emits this illumination device, the brightness | luminance of the part which provided the auxiliary glass tube part 1b falls remarkably. There is no.

  Further, the high-temperature filament 2 is not disposed in the light emitting glass tube portion 1a but is disposed in the auxiliary glass tube portion 1b. The auxiliary glass tube portion 1b straddles the inside and outside of the housing 9 with the bottom of the housing 9 as a boundary. Therefore, the filament 2 is moved away from the optical sheet 20 and the liquid crystal panel 30, and thermal degradation can be prevented.

  Further, since the base 5 outside the auxiliary glass tube portion 1b is connected to the power supply socket 10 mounted on the circuit boards K1 and K2 on the back side of the housing 9, the hot cathode lamps La1 to La4 and the circuit boards K1 and K2 are connected to each other. It is in a directly connected state (no wiring), and the complicated wiring unique to the hot cathode lamp can be eliminated.

  Further, since the hot cathode lamps La1 to La4 are fixed to the circuit boards K1 and K2 through the power supply socket 10, the lamp holder in the housing 9 for fixing the normal lamp becomes unnecessary and is influenced by the influence of the lamp holder. The problem of uneven brightness and mercury aggregation can also be solved.

(Embodiment 2)
The illumination device according to the present embodiment will be described with reference to FIG. 7. A housing 9 and a plurality of circuit boards K1 to K3 disposed on the back surface of the housing 9 are provided. The hot cathode lamps La1 to La8 are the same as the hot cathode lamp described in the first embodiment, and thus redundant description is omitted.

  Next, the housing 9 of the lighting device according to this embodiment shown in FIG. 8 will be described. The housing 9 has a box-like shape with an open front, a rectangular bottom, and two locations near both ends and the middle in the X-axis direction of the bottom, each with four through-holes 7 provided in the Y-axis direction. A total of 16 through-holes 7 are provided at the bottom of the housing 9. Further, on the inner surface of the housing 9, a reflecting material 8 for reflecting the light of the hot cathode lamps La1 to La8 to the front surface of the housing 9 is provided.

  Further, the circuit boards K1 to K3 of the lighting device of the present embodiment will be described. As shown in FIG. 4, four power supply sockets 10 are provided on the circuit boards K1 and K2 arranged at both ends on the back side of the housing 9. For the circuit board K3 that is mounted and arranged at the center of the back side of the housing 9, as shown in FIG. 9, eight power supply sockets 10 and hot cathode lamps La1 to La8 are lit on the circuit board K3. A lighting circuit for mounting is mounted. In other words, the lighting circuit having many high-profile components is mounted on the circuit board K3 disposed in the central portion of the casing 9, and the tall boards are not mounted on the circuit boards K1 and K2 disposed at both ends of the casing 9. I did it. However, it is assumed that the circuit boards K1, K2, and K3 are electrically connected by a ground line or the like.

  Next, the configuration of the present embodiment including the hot cathode lamps La1 to La8, the housing 9, and the circuit boards K1 to K3 will be described. As shown in FIG. 7, the light emitting glass tube portions 1a of the hot cathode lamps La1 and La2 are arranged in the X-axis direction of the housing 9 in a state where one end portions thereof are close to or in contact with each other. At this time, the tube axes of the light emitting glass tube portions 1a of the hot cathode lamps La1 and La2 are substantially on the same straight line, and the directions of the auxiliary glass tube portions 1b are aligned. Further, the same applies to the hot cathode lamps La3 and La4, the hot cathode lamps La5 and La6, and the hot cathode lamps La7 and La8, and the respective groups are arranged in the housing 9 in parallel. At this time, the auxiliary glass tube portions 1b provided at both ends of each of the hot cathode lamps La1 to La8 penetrate through the through-hole 7 of the housing 9 and straddle the bottom of the housing 9 as in the first embodiment. In this state, the power supply socket 10 on the circuit boards K1 to K3 on the back side of the housing 9 is connected. Here, the hot cathode lamps La1, La3, La5 and La7 are connected to the circuit board K1 and the power supply socket 10 mounted on the circuit board K3, and the hot cathode lamps La2, La4, La6 and La8 are connected to the circuit board K2 and the circuit board K3. Are connected to the power supply socket 10 mounted on.

  By arranging the hot cathode lamps La1 to La8 in the housing 9 with the above configuration, the front surface (the direction of the optical sheet and the liquid crystal panel) is irradiated while ensuring the continuity of illumination in the X-axis direction. The illuminance of the emitted light can be partially controlled with respect to the X-axis direction and the parallel direction. That is, when the illumination device of the present embodiment is used in a liquid crystal display device, partial illumination control can be performed in eight areas where the hot cathode lamps La1 to La8 are arranged. Further, since the lighting circuit having many high-profile components is mounted on the circuit board K3 in the center of the housing 9, and the circuit boards K1 and K2 provided at both ends of the housing 9 are not provided with the lighting circuit, A liquid crystal display device with thin ends can be provided (there is a need to make both ends of a backlight unit thin in a liquid crystal display device).

(Embodiment 3)
The illumination device according to the present embodiment is a configuration in which the arrangement of the hot cathode lamps La1 to La8 arranged in the housing 9 is changed as shown in FIG. The light emitting glass tube portions 1a of the cathode lamps La1 and La2 are close to or in contact with each other, and the light emitting glass tube portions 1a of the hot cathode lamps La1 and La2 are substantially parallel with the tube axis shifted. It is arranged in the X-axis direction in the body 9. Further, the same applies to the hot cathode lamps La3 and La4, the hot cathode lamps La5 and La6, and the hot cathode lamps La7 and La8, and the respective groups are arranged in the housing 9 in parallel.

(Embodiment 4)
The illuminating device according to the present embodiment will be described with reference to FIG. 11. The illuminating device includes four hot cathode lamps La1 to La4 whose light emitting glass tube portion 1a is substantially U-shaped or substantially U-shaped, and these. The box-shaped housing 9 whose front surface for housing the hot-cathode lamps La1 to La4 is opened, and the circuit board K3 disposed on the back side of the central portion of the housing 9 are provided. The hot cathode lamps La1 to La4 are the same as the hot cathode lamp described in the first embodiment except that the light emitting glass tube portion 1a is substantially U-shaped or substantially U-shaped. Omitted.

  Next, the housing 9 of the lighting device of this embodiment shown in FIG. 12 will be described. The housing 9 has a box-like shape with an open front, a rectangular bottom, two locations near the middle of the bottom in the X-axis direction, and four through-holes 7 provided in the Y-axis direction. A total of eight through-holes 7 are provided at the bottom of the body 9. Further, a reflective material 8 for reflecting the light of the hot cathode lamp to the front surface of the housing 9 is provided on the inner surface of the housing 9.

  Further, the circuit board K3 of the lighting device according to the present embodiment will be described. The circuit board K3 disposed at the center of the back side of the housing 9 has eight power supply sockets 10 and hot cathodes on the circuit board as shown in FIG. A lighting circuit for lighting the lamps La1 to La8 is mounted.

  Next, the configuration of the present embodiment including the hot cathode lamps La1 to La4, the casing 9, and the circuit board K3 will be described. As shown in FIG. 11, the hot cathode lamps La1 and La2 are arranged in the X-axis direction of the housing 9 in a state where both end portions of the respective light emitting glass tube portions 1a are close to or in contact with each other. At this time, the directions of the auxiliary glass tube portions 1b of the hot cathode lamps La1 and La2 are aligned. The same applies to the hot cathode lamps La2 and La4, which are arranged in the housing 9 in parallel with the group of the hot cathodes La1 and La2. At this time, the auxiliary glass tube portions 1b provided at both ends of each hot cathode lamp pass through the through-hole 7 of the housing 9 and straddle the bottom of the housing 9 in the same manner as in the first embodiment. The power supply socket 10 on the circuit board K3 on the back side of the housing 9 is connected. Here, the hot cathode lamps La1 to La4 are connected to the power supply socket 10 mounted on the circuit board K3.

  By arranging the hot cathode lamps La1 to La4 in the casing 9 with the above configuration, it is possible to partially control the luminance in the X-axis direction and the parallel direction as in the second embodiment. In addition, only one circuit board K3 is required to connect and fix the hot cathode lamps La1 to La4. In addition, since the circuit board is not provided at both ends of the housing 9, the liquid crystal display device including the lighting device according to the present embodiment can reduce both ends of the housing 9.

(Embodiment 5)
The lighting device according to the present embodiment has basically the same configuration as that of the first embodiment, but only the positional relationship between the filament 2 of the hot cathode lamp and the bottom of the housing 9 is different. These configurations will be described with reference to FIG. 13. The filament 2 is disposed in the auxiliary glass tube portion 1 b straddling the bottom of the housing 9, but is completely disposed outside the housing 9. . That is, the filament 2 is disposed in the space between the back surface of the housing 9 and the circuit board.

  By adopting the above-described configuration, the filament 2, which is a high-temperature heat source, the optical sheet 20, and the liquid crystal panel 30 can be further away from each other, and the effect of preventing thermal deterioration is great. Moreover, since the temperature in the housing 9 can be lowered, the efficiency of the hot cathode lamp can be improved.

(Embodiment 6)
The lighting device according to the present embodiment has basically the same configuration as that of the first embodiment, except that an insulating member 13 is disposed between the through-hole 7 at the bottom of the housing 9 and the auxiliary glass tube portion 1b. These configurations are shown in FIG. An insulating member 13 such as silicon resin is disposed between the through-hole 7 at the bottom of the housing 9 and the auxiliary glass tube portion 1b in which the filament 2 is disposed. Here, since the tube wall temperature of the auxiliary glass tube portion 1b in the vicinity where the filament 2 is disposed is always about 100 ° C., it is desirable that the insulating member 13 has a heat resistant temperature of 150 ° C. or higher. Furthermore, an insulating member having elasticity is desirable. By adopting the configuration as described above, the insulating member 13 having elasticity prevents the auxiliary glass tube portion 1b from being damaged due to impact or vibration, and ensures insulation between the housing 9 and the hot cathode lamp.

FIG. 2 is a cross-sectional view of a hot cathode lamp used in the illumination device of Embodiment 1. It is a front view of the illuminating device of Embodiment 1. FIG. It is a front view of the housing | casing used for the illuminating device of Embodiment 1. FIG. FIG. 3 is a perspective view of a circuit board used in the lighting device according to the first embodiment. It is sectional drawing of the illuminating device of Embodiment 1. FIG. It is sectional drawing of the illuminating device of Embodiment 1. FIG. It is a front view of the illuminating device of Embodiment 2. It is a front view of the housing | casing used for the illuminating device of Embodiment 2. FIG. It is a perspective view of the circuit board used for the illuminating device of Embodiment 2. It is a front view of the illuminating device of Embodiment 3. It is a front view of the illuminating device of Embodiment 4. It is a front view of the housing | casing used for the illuminating device of Embodiment 4. It is sectional drawing of the illuminating device of Embodiment 5. It is sectional drawing of the illuminating device of Embodiment 6. It is a schematic block diagram of the conventional hot cathode lamp backlight unit. It is sectional drawing of the conventional hot cathode lamp backlight unit. It is explanatory drawing of the conventional hot cathode lamp. It is explanatory drawing of the other conventional hot cathode lamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass tube 1a Luminous glass tube part 1b Auxiliary glass tube part 2 Filament 3 Lead wire 4 Pin 5 Base 6 Phosphor 7 Through-hole 8 Reflector 9 Case 10 Power supply socket K1 Circuit board K2 Circuit board

Claims (7)

A light-emitting glass tube portion having a function as illumination, and an auxiliary glass tube portion provided at both ends of the light-emitting glass tube portion continuously in a direction substantially perpendicular to the axial direction of the light-emitting glass tube portion and also having a function as illumination The inside of the auxiliary glass tube portion is provided with a filament and a lead wire connected to both ends of the filament, and the base having a pin connected to the lead wire outside the auxiliary glass tube portion A hot cathode lamp having
Provided with a plurality of through-holes at the bottom, a reflective material is arranged on the inner surface, the front surface is open, and a box-shaped housing for storing the hot cathode lamp;
A power supply socket for obtaining connection with the base is mounted toward the back surface of the housing, and is fixed substantially parallel to the back surface of the housing at an arbitrary distance at a position where the through-hole on the back surface of the housing is arranged. A circuit board,
The auxiliary glass tube part of the hot cathode lamp penetrates the through-hole of the housing and feeds the base and the circuit board over the inside and outside of the housing with the bottom of the housing as a boundary. A lighting device, wherein a socket is connected. A plurality of the hot-cathode lamps whose light emitting glass tube portions are substantially straight are arranged side by side in the axial direction so that the directions of the respective auxiliary glass tube portions are aligned with the end portions of the light emitting glass tube portions approaching or in contact with each other. The lighting device according to claim 1, wherein a group of a plurality of hot cathode lamps arranged side by side in the axial direction is arranged in parallel in the casing. The two auxiliary cathode lamps each having a light-emitting glass tube portion that is substantially U-shaped or substantially U-shaped, with both ends of the light-emitting glass tube portions of each hot-cathode lamp being close to or in contact with each other. The group of two said hot cathode lamps arrange | positioned along with the axial direction so that the direction of a tube part may align, and was arrange | positioned in the said state was arrange | positioned in parallel in the said housing | casing. Lighting device. The illuminating device according to any one of claims 1 to 3, wherein the filament and the lead-in wire arranged inside the auxiliary glass tube portion are arranged outside the housing. The lighting device according to claim 1, wherein a lighting circuit for lighting the hot cathode lamp is mounted on the circuit board in addition to the power supply socket. The lighting device according to claim 1, wherein an insulating member is disposed between the housing and the auxiliary glass tube portion at the through-hole of the housing. A liquid crystal display device comprising the illumination device according to claim 1.

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