JP2006073306A - Lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting apparatus which can irradiate uniformly throughout the whole display surface of a liquid crystal display device, and can be used as a direct-downward backlight with a narrow frame or as a side-light type backlight capable of being reduced in thickness. <P>SOLUTION: Discharge lamps 1, 11 each equipped with a plurality of respective parallel straight tube portions 1a, 1b connected through a bridge tube 4 are used as a light source of a lighting apparatus forming a uniform surface light source. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lighting device suitable for a backlight of a liquid crystal television or the like, or a video display for a car navigation system.

  A backlight illumination device such as a liquid crystal television or a liquid crystal meter usually uses a cold cathode discharge lamp as a light source, and illuminates the liquid crystal almost uniformly in a plane from the back of a liquid crystal panel such as a small liquid crystal television or a liquid crystal meter. Often used to display surfaces. In car navigation systems that provide traffic information to car drivers, cold cathode discharge lamps are used as backlights for liquid crystal display devices such as TV monitors that display the current position and direction of travel of the car. There are many.

  FIG. 10 is an example of a conventional backlight illumination device, and is a perspective view showing an exploded perspective view of the basic structure of a direct type. In FIG. 10, a reflective casing 21 having a reflective surface has a shallow dish shape whose front surface is openable. A plurality of cold cathode low-pressure discharge lamps 22 are provided inside, and a power supply terminal side is an elastic body such as rubber. The lamp holder 24 is made of and electrically connected to each other and is arranged in a plane. In addition, a synthetic resin-based diffuse transmission plate 25 is detachably attached to the opening formed with the reflection surface of the reflective casing 21.

  The cold cathode low-pressure discharge lamp 22 is formed, for example, by connecting a plurality of U-shaped cold cathode discharge lamps 22 and 22 in series at a connection terminal portion 23 and using both ends as power supply terminals.

  The reflection type reflection casing 21 is made of, for example, a polycarbonate resin or a polycarbonate resin mixed weather resistant resin. In addition, the bottom wall surface 21a of the reflective casing 21 has a concavo-convex surface in a certain direction (stripe-shaped projections 21b are formed), and this concavo-convex surface functions as a reflective surface, while a cold cathode low-pressure discharge lamp. 22 is locked by a locking piece 21c such as a bent portion 22a, and is disposed and mounted in a planar manner inside the reflective casing 21. Further, the cold cathode low-pressure discharge lamp 22 has a lamp holder 24 sandwiched and supported by a support groove 26a of a pair of support members 26 integrally installed on the side wall portion 21d of the reflective casing 21, so that the reflective type It is fixed and mounted inside the casing 21.

In these configurations, the both ends of the cold cathode low-pressure discharge lamp 22 are fitted and supported in the support groove 26a of the support member 26 via the lamp holder 24. The deformation and use of a minute bulb accompanying thermal expansion that occurs during lighting are used. The external force due to the impact or vibration at the time is absorbed by the rubber-based elastic material holder 23 to prevent the cold cathode low-pressure discharge lamp 22 from being damaged, while providing electrical insulation. (For example, see Patent Document 1)
In addition, when an example of a sidelight type in a conventional backlight illumination device is shown in a cross-sectional view in FIG. 11, a planar light source device (illumination device) includes a light guide plate 33 made of a transparent material, A bar-shaped (straight tube) light source (discharge lamp) 31 disposed in the vicinity of the light incident surface which is the side surface end of the light guide plate 33 and a surface other than the surface of the rod-shaped light source 31 facing the light guide plate 33. A cylindrical reflection member 32 covering the portion, a planar reflection member 34 disposed close to a position facing the lower surface of the light guide plate 33, a light guide plate 33, a light source 31, and both reflection members 32, 34 It is comprised from the holding member 35 to accommodate. A liquid crystal display device can be obtained by placing the liquid crystal display element 37 on the planar light source device. (For example, see Patent Document 2)
In the case shown in FIG. 11, two straight tube type discharge lamps 31 and 31 are used as the light source, but a case where a U-shaped discharge light lamp is used is schematically shown in FIG. 12. In other words, the straight tube portions 22c and 22d of the U-shaped discharge lamp 22 are disposed in parallel with the incident surface 33a of the light guide plate 33 having a thickness t1, and the light guide plate of the discharge lamp 22 A reflecting plate 32 a is disposed on the side that does not face 33.

Further, as shown in FIG. 13, a single-ended fluorescent lamp is used as an integrated light source having two bar-shaped (straight tube) light sources (discharge fluorescent lamps) that are parallel to the U-shaped tube. Exists. This single-necked fluorescent lamp is thinner than the straight tube portions 22c and 22d that connect the non-cap-side end portions (end portions opposite to the electrodes 41a and 41b) of the straight tube portions 22c and 22d, which are each arc tube. It communicates via a bridge pipe 36 having a diameter. (For example, see Patent Document 3)
However, there is no conventional example in which a single-piece fluorescent lamp as shown in FIG. 13 is used in a backlight illumination device.
JP-A-10-39808 (paragraph numbers 0003 to 0005) JP 2001-126523 A (FIG. 1) JP-A-8-255686 (paragraph number 0006)

  The illumination light of the backlight unit is required to be uniformly irradiated as a surface light source over the entire display surface of the liquid crystal display unit. If there is uneven brightness in the illumination light of the backlight unit, the brightness of the liquid crystal display screen becomes uneven, making it difficult to see the display contents. Further, when the backlight device is mounted on a product, it is required to narrow the frame so that the frame portion of the liquid crystal display unit becomes narrow due to slimming of the product and design.

  That is, for uniform illumination of the liquid crystal display screen, it is desirable that linear light sources as illumination light sources are arranged at high density in order to uniformly irradiate the entire display surface of the direct liquid crystal display unit.

  One of the causes of uneven brightness of illumination light is the nonuniformity of the phosphor layer coated on the inner wall surface of the discharge lamp by coating. In particular, in the case of a bent tube such as a U-shaped tube, the bent tube itself is a straight tube that is bent and folded, so that the total length is longer than when two straight tubes are arranged in parallel. Is almost twice as long. In that case, since the applied phosphor layer is applied in the major axis direction in the application process, it is technically very difficult to apply uniformly over a long entire length, and as a practical problem, nonuniformity due to uneven application The generation of a phosphor layer cannot be avoided.

  Further, when the discharge lamp is a bent tube such as a U-shaped tube, as shown in the schematic diagram of FIG. 14, the minimum dimension of the distance P1 between the straight tube portions 22c and 22d facing each other due to a manufacturing problem is from the manufacturing point of view. There is a limit and it is difficult to set it to 5 mm or less. As shown in FIG. 15, even if the electrodes 41a and 41b are of the internal electrode type provided inside the straight pipe portions 22c and 22d, the electrodes 42a and 42b are straight pipes as shown in FIG. The same applies to the case of the external electrode type provided outside the portions 22c and 22d.

  Therefore, when a bent tube such as a U-shaped tube is used as the light source, the pitch of the straight tube portion cannot be reduced, so that the light emitting portion becomes discontinuous and the entire display surface of the liquid crystal display unit is irradiated uniformly. It is extremely difficult.

  As for the narrowing of the frame, in the case of a bent tube such as a U-shaped tube, as shown schematically in FIG. 17, the bent portion 22a of the discharge lamp 22 is not suitable for uniform illumination in terms of shape and brightness. It is. In order to solve this problem, the bent portion 22a of the discharge lamp 22 is hidden by the frame portion 26. As a result, the area of the frame portion 26 is increased, making it difficult to realize a narrow frame.

  On the other hand, in the sidelight type backlight illumination device, when a bent tube such as a U-shaped tube is used as the light source, the thickness (t1) of the light guide plate 33 as shown in the schematic diagram in FIG. The straight pipe portions 22c and 22d of a bent pipe such as a U-shaped pipe are arranged in parallel to the direction of Therefore, the size of the bent tube, which has a restriction on the minimum size in manufacturing, is a main factor for determining the minimum value in the thickness direction of the backlight device. Therefore, it is difficult to reduce the thickness of the backlight device.

  The present invention has been made based on these circumstances, and can be used as a direct-type backlight that can irradiate uniformly over the entire display surface of a liquid crystal display unit or the like and has a narrow frame portion, and can also be reduced in thickness. An object of the present invention is to provide an illuminating device that can be used as a sidelight-type backlight.

According to the present invention, the noble gas and mercury are sealed inside the glass tube, and the phosphor layer is coated on the inner wall surface in the opposite directions with respect to the major axis direction, and is arranged opposite to each other. In the two straight pipe portions, an electrode is disposed on one end side of each straight pipe portion, and the vicinity of the sealed other end side is formed integrally with each other by airtight communication with a bridge pipe. A discharge lamp,
An illumination apparatus comprising an illumination light source including a boost lighting circuit for applying a voltage to the discharge lamp.

Further, according to the present invention, the first and the second tubes are arranged in such a manner that a rare gas and mercury are enclosed in a glass tube, and a phosphor layer is coated on the inner wall surface in directions opposite to each other with respect to the major axis direction. In the second straight pipe portion, an electrode is disposed on one end side of each straight pipe portion, and the vicinity of the sealed other end side is airtightly communicated with each other by a bridge pipe and formed integrally. A discharge lamp,
A step-up lighting circuit for applying a voltage to the discharge lamp;
A reflective casing having a reflective surface on one side of the surface facing the discharge lamp and an opening on the other side, and holding the discharge lamp fixedly;
An illuminating device for a direct type backlight having a diffusion transmission plate attached to the opening of the reflective casing.

  Further, according to the present invention, the discharge lamp is arranged for a plurality of flat surfaces facing the diffuse transmission plate, and is fixedly held by the reflective casing, for a direct type backlight. It is a lighting device.

Further, according to the present invention, the first and the second tubes are arranged in such a manner that a rare gas and mercury are enclosed in a glass tube, and a phosphor layer is coated on the inner wall surface in directions opposite to each other with respect to the major axis direction. In the second straight pipe portion, an electrode is disposed on one end side of each straight pipe portion, and the vicinity of the sealed other end side is airtightly communicated with each other by a bridge pipe and formed integrally. A discharge lamp,
A step-up lighting circuit for applying a voltage to the discharge lamp;
A reflector having a reflecting surface formed parallel to the major axis direction of the discharge lamp, and one of which is open;
An illumination device for a sidelight-type backlight, comprising: a translucent light guide plate having an end attached to the opening of the reflector.

  According to the invention, it is the lighting device characterized in that an outer diameter of the bridge pipe communicating with the straight pipe portion is smaller than an outer diameter of the straight pipe portion.

  Further, according to the present invention, the discharge lamp including a plurality of parallel straight tube portions communicated via the bridge tube is connected to a single boost lighting circuit. Device.

  According to the invention, the straight tube portion communicated via the bridge tube of the discharge lamp is an illuminating device characterized in that an outer diameter of the straight tube portion is 6 mm or less.

  According to the invention, the bridge tube of the discharge lamp is arranged so as to be outside the diffuse transmission plate.

  According to the invention, the straight tube portion of the discharge lamp is disposed so as to be inclined so that the straight tube portion having a small diameter is close to the light guide plate with respect to the incident surface to the light guide plate. It is the lighting device characterized by having.

  According to the present invention, it is possible to irradiate uniformly over the entire display surface of the liquid crystal display device, and it can be used as a direct-type backlight with a narrow frame portion, or it can be thinned. An illumination device that can be used as a light is realized.

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

  First, a discharge lamp that is an illumination light source used in the illumination device of the present invention will be described.

  As shown in FIG. 1, the discharge lamp 1 has an integrated structure in which first and second straight tube portions 1a and 1b are joined by a bridge tube 4 having a diameter smaller than that of the straight tube portions 1a and 1b. This is an airtight glass tube (glass bulb). Moreover, the outer surface electrode or the internal electrode is formed in the both ends of a glass tube as the electric power feeding terminals 1c and 1c, respectively. In addition, the discharge lamp 1 is formed by coating phosphor layers 1d on the inner wall surfaces of the straight tube portions 1a and 1b and the bridge tube 4, and is a cold cathode inside both ends of the straight tube portions 1a and 1b. The electrode is sealed, and a required amount of a rare gas (for example, at least one of argon, krypton, xenon, and neon) and mercury are sealed inside. The inner wall surface of the bridge tube 4 may not be coated with the phosphor layer 1d.

The phosphor layer 1d coated on the inner wall surface of each straight pipe portion 1a, 1b is excited by ultraviolet rays radiated from mercury and converted to visible light. It is composed of rare earth phosphor particles having a diameter of about 4 μm. As the three-wavelength phosphor, for example, Y ₂ O ₃ : Eu as a red phosphor having a peak wavelength near 610 nm, LaPO ₄ : Ce, Tb as a green phosphor having a peak wavelength near 540 nm, and a peak near 450 nm (SrCaBa) ₅ (PO ₄ ) ₃ Cl: Eu is used as a blue phosphor having a wavelength. Further, boron oxide or the like as a binder component is added.

  The coating on the inner wall surface of each straight pipe portion 1a, 1b is performed by applying a phosphor slurry (phosphor particle suspension) prepared with rare earth phosphor particles, an organic binder and water as components, and thereafter It is formed by drying and baking.

  In the application by flow coating, each straight pipe portion 1a, 1b is supported and arranged substantially upright, and the phosphor slurry is caused to flow on the inner wall surface of each straight pipe portion 1a, 1b with the upper end opening side as an injection port, and is caused to flow under its own weight. Thus, it is applied in the major axis direction of each straight pipe portion 1a, 1b. Alternatively, the phosphor slurry is sucked (depressurized) from one end opening of each straight pipe portion 1a, 1b to the other end opening side, and then is applied in the major axis direction of each straight pipe portion 1a, 1b by flowing under its own weight.

  Therefore, according to these application methods, in any case, the phosphor slurry flows from one to the other along the major axis direction of each straight pipe portion 1a, 1b. As a result, the phosphor layer 1d formed on the inner wall surface of each straight pipe portion 1a, 1b has a coating direction with respect to the major axis direction.

  That is, in the discharge lamp using the straight tube portion formed by these coating methods, the application direction of the two straight tube portions 1a and 1b communicated by the bridge tube 4 as shown in FIG. In the same direction as indicated by arrows F1 and F2, and as shown in FIG. 2B, the application directions of the two straight pipe portions 1a and 1b communicated by the bridge pipe 4 are indicated by arrows F3 and F4. There is a case in the opposite direction as shown by.

  The graph of FIG. 3 is an example of measuring the luminance distribution when actually used in a lighting device. The direct-type backlight described later using a discharge lamp having the same coating direction shown in FIG. The diffuse transmission plate of the illumination device in the longitudinal direction (600 mm) of the discharge lamp 1 for the illumination device and the direct-type backlight illumination device using the discharge lamp with the coating direction opposite to that shown in FIG. It is the graph which measured and showed luminance distribution in. The vertical axis represents the plate surface luminance of the transmission diffusion plate, and the horizontal axis represents the major axis direction of each straight pipe portion 1a, 1b.

  A dotted line A is a direct type backlight using a discharge lamp having the same coating direction, and a gradient is seen in the luminance distribution in the longitudinal direction, and uneven luminance in the longitudinal direction is observed.

  On the other hand, a solid line B is a discharge lamp whose application direction is opposite, the luminance distribution is almost horizontal in the longitudinal direction, and the luminance is uniformly distributed throughout the longitudinal direction.

  Any luminance distribution can be used according to the purpose of use, but the direction of application is opposite, especially for a direct backlight of a liquid crystal display device that requires high quality and uniform luminance. It is preferred to use a directional discharge lamp.

  The cause of the difference in the luminance distribution depending on the application direction of the phosphor layer 1d of each straight tube portion 1a, 1b of the discharge lamp 1 is that the small bend of the glass tube of each straight tube portion 1a, 1b is due to the film thickness. The effect of non-uniformity is that the film thickness of the uppermost portion of the glass tube of about 100 mm is particularly thin, and further, the closer the lower end of the glass tube is, the greater the viscosity of the phosphor liquid that flows under its own weight and the non-uniform film thickness. It is conceivable that this is likely to occur.

  Next, the lighting device of the present invention will be described.

  The illuminating device of the present invention is roughly classified into a direct backlight type and a sidelight type backlight. Hereinafter, the form of the direct type backlight and the form of the sidelight type backlight will be described in order.

  4 is a perspective plan view showing a basic configuration of an illuminating device which is a direct type backlight, and FIG. 5 is a cross-sectional view taken along line AA of FIG.

  As shown in FIGS. 4 and 5, the lighting device that is a direct type backlight has two straight pipe portions 1 a and 1 b formed in parallel on the same plane, and each straight pipe portion 1 a and 1 b A cold cathode discharge lamp 1 (hereinafter simply referred to as a discharge lamp), which is an integrated light source joined by a bridge tube 4 having a diameter smaller than that of the tube portions 1a and 1b, has a feeding terminal 1t of the discharge lamp 1 made of rubber or the like. It is held by a lamp holder 2 made of an elastic body, and is housed in a reflective casing 3 having a shallow dish shape whose front surface is openable. Further, in accordance with the structure shown in the exploded perspective view in FIG. 10, the lamp holder 2 mounted and arranged on the power supply terminal 1t side of the discharge lamp 1 is attached to the side wall portion 3a of the reflective casing 3 having a reflective surface. The bridge member 4 and the like of the discharge lamp 1 are locked by a locking piece 7 and mounted in a planar manner by being sandwiched and supported by a support member 6 that is integrally installed. Further, a synthetic resin-based diffuse transmission plate 5 is detachably attached to the opening of the reflective casing 3 so as to constitute a uniform surface light source.

  The reflective casing 3 is made of, for example, polycarbonate resin, and is formed in a shallow dish shape having an open front surface. The bottom wall surface 3b is formed with a reflection surface of a specular reflection layer formed by vapor deposition of silver.

  As described above, in the discharge lamp 1, as shown in FIG. 1, the plurality of straight tube portions 1a and 1b are joined by the bridge tube 4 having a diameter smaller than that of the respective straight tube portions 1a and 1b. This is a single-piece glass bulb. In addition, external electrodes or internal electrodes are formed as power supply terminals 1c and 1c, respectively, at both ends of the bulb. Further, in the discharge lamp 1, a phosphor layer 1d is formed on the inner wall surfaces of the straight tube portions 1a and 1b and the bridge tube 4, and electrodes serving as cold cathodes are sealed at both ends of the straight tube portions 1a and 1b, respectively. In addition, the required amount of rare gas and mercury are enclosed inside.

  In addition, about the direction of application | coating of the fluorescent substance layer 1d of each straight tube | pipe part 1a, 1b, each parallel straight tube | pipe part 1a, 1b which opposes is parallel to the illuminating device in the case of using for a highly accurate display apparatus. It is preferable to use the phosphor layers 1d whose coating directions in the major axis direction are different from one another. As the tube portions 1a and 1b, those having the same coating direction in the major axis direction of the coated phosphor layer 1d can be used.

  Each discharge lamp 1 is arranged on the bottom wall surface 3b of the reflective casing 3 so as to be opposed to the diffuse transmission plate 5 and arranged in a plane, and in the same manner as in the case shown in FIG. Are connected in series at the connection terminal section, and both ends are formed as a power feeding section and connected to a single boost lighting circuit (not shown).

As a preferred example of the dimensions of each discharge lamp 1, as shown in FIG. 6, the outer diameters of the straight pipe portions 1a and 1b are D1 and D2, and the opposing distance between the straight pipe portions 1a and 1b is P. When the welding dimension of the bridge portion by the bridge tube 4 is L,
D1, D2 ≦ 6mm
[(D1 + D2) / 2] ≦ 2P
D1, D2> L
Is set to

  When the lighting device having such a configuration is turned on and the light distribution characteristics radiated through the diffusion transmission plate 5 are measured and evaluated, as described later, a luminance distribution with almost no luminance unevenness is obtained as a surface light source. It was. Therefore, when used as a backlight of a liquid crystal display device, the luminance distribution radiated through the diffusing and transmitting plate 5 has substantially uniform luminance (no luminance unevenness) on the entire surface and good visibility. A liquid crystal display surface can be irradiated.

  FIGS. 7A and 7B are explanatory views showing comparison of uniform light-emitting areas of the illumination device. FIG. 7A shows the case of the present invention, and FIG. 7B shows the case of the prior art. That is, the width of the turn-up side of the discharge lamp 21 is a bent structure in the prior art, whereas the discharge lamp 1 used in the lighting device of the present invention has a welded structure of the bridge tube 4.

  In the bent structure of the conventional example shown in FIG. 7B, since the brightness of the bent portion 22a is lower than that of the straight tube portions 22b and 22c, it cannot be used in the light emitting area E as a uniform light source. Therefore, it is necessary to arrange the bent portion 21a outside the uniform surface light source (light emitting area E). On the other hand, also in the structure of the illuminating device using the bridge tube 4 of the present invention shown in FIG. 7A, it is necessary to dispose the bridge tube 4 portion outside the light emitting area E (uniform surface light source).

  When these arrangements are compared, in FIGS. 7A and 7B, the portion of the bridge tube 4 is formed so that the portion that protrudes from the light emitting area E is smaller than the bent portion 22a that has been conventionally used. (F2> F1). Therefore, when the discharge lamp 1 connected by the bridge tube 4 is mounted on a product such as a liquid crystal display device, the discharge lamp 1 can correspond to a slimmer product structure than the discharge lamp 22 having a bent structure.

  Next, an illumination device which is a sidelight type backlight will be described.

  The basic structure itself of the discharge lamp 11 used in this embodiment is the same as that of the discharge lamp 1 used in the illumination device which is the above-described direct type backlight, but as shown in FIG. In this case, the straight pipe portions 11a and 11b have different outer diameters, one is a large diameter straight pipe portion 11a, and the other is formed by a small diameter straight pipe portion 11b, and both straight pipe portions 11a and 11b are bridges. Connected by a tube 4.

  FIG. 9 is an explanatory diagram showing a side cross section of a sidelight-type backlight illumination device according to an embodiment of the present invention. A reflector 13 having a U-shaped cross section is provided on one side surface of the light guide plate 12. That is, the reflector has a reflecting surface formed in parallel to the long axis direction of the discharge lamp, and one of the reflectors is open, and the end of the light-transmitting light guide plate is attached to the opening.

  Inside the reflector 13, a line connecting the centers of the straight pipe portions 11a and 11b with which the discharge lamp 11 is parallel is inclined at an angle of approximately 45 degrees. The discharge lamp 11 is arranged so that one of the parallel straight tube portions 11a and 11b has a large diameter and the other has a small diameter, and the light guide plate 12 side becomes a small diameter straight tube portion 11b. With this arrangement, the light emitted from the large-diameter straight tube portion 11a is partially blocked by the small-diameter straight tube portion 11b, but is incident on the light guide plate 12 without being totally blocked. The brightness is not hindered. Moreover, the dimension t2 in the thickness direction of the light guide plate 12 can be greatly reduced (t2 <t1) as compared with the arrangement of the discharge lamp 21 shown in FIG. Therefore, when mounted on a product, it is possible to correspond to a slim product structure, and the practical value is high.

The external view of the discharge lamp used for the illuminating device of this invention. (A) And (b) is explanatory drawing of the application | coating direction of the straight tube | pipe part of the discharge lamp used for the illuminating device of this invention. The graph which measured and showed the luminance distribution in the diffuse transmission board of the illuminating device by the difference in the application | coating direction of the straight tube | pipe part of the discharge lamp used for the illuminating device of this invention. The perspective top view which shows the basic composition of the illuminating device of this invention. Sectional drawing along the AA line of FIG. The dimension explanatory drawing of the discharge lamp used for the illuminating device of this invention. (A) And (b) is explanatory drawing which shows the comparison of the uniform light emission area of an illuminating device, (a) is the case of this invention, (b) is the conventional case. FIG. 3 is an external view of a discharge lamp used in a sidelight type backlight illumination device. Explanatory drawing which shows the side cross section of the illuminating device for backlights of a sidelight type. The exploded perspective view of the conventional illuminating device for backlights. Sectional drawing of the conventional illuminating device for backlights of a sidelight type. The schematic diagram of the conventional illuminating device for backlights of a sidelight type. The schematic diagram of a one-piece metal-type fluorescent lamp. An explanatory schematic diagram of a bent tube. An explanatory schematic diagram of a bent tube. An explanatory schematic diagram of a bent tube. Explanatory drawing of the illuminating device using between bending | flexion.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,11 ... Discharge lamp, 1a, 1b ... Straight pipe part, 1t ... Feeding terminal, 2 ... Lamp holder, 3 ... Reflective casing, 4 ... Bridge tube, 5 ... Diffuse transmission plate, 12 ... Light guide plate, 13 ... Reflector

Claims (9)

Noble gas and mercury are enclosed in the glass tube, and the phosphor layer is coated on the inner wall surface in opposite directions with respect to the major axis direction. In addition, an electrode is disposed on one end side of each straight tube portion, and the vicinity of the sealed other end side is integrally formed in a bridge tube so as to be airtightly connected to each other; and
An illuminating device comprising an illumination light source including a boost lighting circuit for applying a voltage to the discharge lamp. Noble gas and mercury are enclosed in the glass tube, and the phosphor layer is coated on the inner wall surface in opposite directions with respect to the major axis direction. In addition, an electrode is disposed on one end side of each straight tube portion, and the vicinity of the sealed other end side is integrally formed in a bridge tube so as to be airtightly connected to each other; and
A step-up lighting circuit for applying a voltage to the discharge lamp;
A reflective casing having a reflective surface on one side of the surface facing the discharge lamp and an opening on the other side, and holding the discharge lamp fixedly;
An illuminating device for a direct type backlight, comprising: a diffuse transmission plate mounted in the opening of the reflective casing.   3. The illumination device for direct type backlight according to claim 2, wherein a plurality of the discharge lamps are arranged in a plane so as to face the diffuse transmission plate and are fixedly held in the reflection type casing. . Noble gas and mercury are enclosed in the glass tube, and the phosphor layer is coated on the inner wall surface in opposite directions with respect to the major axis direction. In addition, an electrode is disposed on one end side of each straight tube portion, and the vicinity of the sealed other end side is integrally formed in a bridge tube so as to be airtightly connected to each other; and
A step-up lighting circuit for applying a voltage to the discharge lamp;
A reflector having a reflecting surface formed parallel to the major axis direction of the discharge lamp, and one of which is open;
An illumination device for a sidelight type backlight, comprising: a translucent light guide plate having an end attached to the opening of the reflector.   The lighting device according to any one of claims 2 to 4, wherein an outer diameter of the bridge pipe communicating with the straight pipe portion is smaller than an outer diameter of the straight pipe portion.   6. The discharge lamp having a plurality of parallel straight tube portions communicated via the bridge tube is connected to a single step-up lighting circuit. The lighting device according to any one of the above.   The straight tube portion communicated via the bridge tube of the discharge lamp has an outer diameter of the straight tube portion of 6 mm or less. Lighting equipment.   The lighting device according to claim 2, wherein the bridge tube of the discharge lamp is disposed so as to be outside of the diffuse transmission plate.   The straight tube portion of the discharge lamp is disposed so as to be inclined with respect to an incident surface to the light guide plate so that the small diameter straight tube portion is close to the light guide plate. The lighting device according to claim 4.

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