TWI383423B - Lamp, backlight, and liquid crystal display device - Google Patents

Description

Lamp, backlight module and liquid crystal display device

The invention relates to a lamp tube, in particular to a lamp module of a backlight module and a liquid crystal display device.

Because the liquid crystal display is a non-self-illuminating device, a backlight is required to provide a light source. The backlight module is divided into a direct type and a side light type according to the installation position; the light source used in the backlight module can be cold. Cathode Fluorescent Lamp (CCFL), External Electrode Fluorescent Lamp (EEFL), Differential Electrode Fluorescent Lamp (DEFL) or Light Emitting Diode (LED), etc.

The first figure shows a cold cathode fluorescent lamp of the prior art. The lamp tube 1 is composed of a glass tube 10, a fluorescent material 12 coated on the inner surface of the glass tube 10, an inert gas 14 injected into the glass tube 10, and two The electrode 16 mounted on the edge of the glass tube 10 is composed of two wires 18 electrically connected to the two electrodes 16 and extending out of the glass tube 10.

When an alternating voltage is applied to a high voltage electrode 16 and a low voltage electrode 16 of the electrode 16, the glass tube 10 emits electrons from the low voltage electrode 16 to collide with the inert gas, the number of electrons increases exponentially, and the inert gas is excited by electrons. Ultraviolet rays are emitted, and the ultraviolet rays collide with the fluorescent material 12 to emit visible light.

In addition to the circular shape, the tube can be of other shapes. As shown in the second figure, Taiwan Patent Publication No. 200725119 discloses a lamp tube 2 having an elliptical glass tube 21 and two circular surface electrodes 22, wherein a fluorescent material 23 is formed in the glass tube 21. The wall and inert gas 24 are sealed in the glass tube 21. The elliptical glass tube 21 has a long axis and a short axis. The invention discloses that the excitation area of the phosphor material 23 of the elliptical glass tube 21 can be increased as compared with the circular glass tube, thereby improving luminous efficiency and brightness.

With the trend of large-scale liquid crystal display, the length of the lamp tube is inevitably increased regardless of the shape of the lamp tube. The thickness and diameter of the glass tube must also be increased, so that the brightness and luminous efficiency of the lamp tube are reduced, and the cost of the backlight module is increased. The ratio of the growth of the multiples and the cost of the liquid crystal display of the backlight module is also increasing.

Therefore, it is urgent to provide a lamp, a backlight module and a liquid crystal display device with better luminous efficiency and brightness, and reduce the cost of the backlight module and the liquid crystal display.

An object of the present invention is to provide a backlight module and a liquid crystal display device with better luminous efficiency and brightness, and reduce the cost of the backlight module and the liquid crystal display.

According to the above object, the present invention provides a lamp tube comprising a hollow transparent lamp body having unequal wall thicknesses; and a light beam emitted from the inside to the outside by the hollow portion of the lamp body. The lamp tube may further include a first electrode disposed at the first end of the lamp body; a second electrode disposed at the first end of the lamp body; a phosphor material disposed on the inner surface of the hollow portion of the lamp body; The inert gas is sealed to the hollow portion of the lamp body; and the two wires are electrically connected to the first electrode and the second electrode, respectively.

According to the above object, the present invention provides a direct-type backlight module comprising a bottom case, wherein the bottom case is provided with a plurality of the above-mentioned "unequal pipe wall thickness" lamps; and a diffusion material is disposed above the bottom case.

According to the above object, the present invention provides a side-in-light backlight module comprising a plurality of "unequal wall thickness" lamps disposed on a side of the backlight module; a reflector surrounding the lamp; a light guide plate, The light incident on the tube is converted into a surface light source; a reflector is disposed at the bottom of the light guide plate; and a diffusion material is disposed above the light guide plate.

According to the above objective, the present invention provides a liquid crystal display device comprising a liquid crystal panel; and a backlight module, wherein the backlight module can be the above-mentioned direct type backlight module or a side edge light-emitting backlight module.

Conventional techniques have improved luminous efficiency and brightness by changing the geometry of the tube, and the results are still insufficient. The invention believes that under the entire backlight module structure, the optical design is nothing more than collecting the light efficiently into the visible area. In addition to improving the luminous efficiency, the brightness of the backlight module can be effectively increased, and the energy loss is also a direction that can be considered. . Since the lamp is a kind of line light source, the form of light emission is diverged in all directions. If the light can be guided to a desired place, the light source loss can be reduced, and the luminous efficiency can be improved.

The third embodiment shows a lamp tube according to an embodiment of the present invention. A lamp tube 3 includes a triangular, hollow, and transparent lamp body 31. The material of the lamp body 31 can be glass and the lamp body 31 has unequal and uneven The wall thickness, the light 32 is emitted from the inside to the outside of the glass tube, the upper plane can be defined as the light exit surface 33, and the light is also emitted from the other two surfaces.

Compared with the prior art, the present invention utilizes unequal wall thicknesses to form a concave lens exit surface 33 having a thinner central portion and a thicker edge. The light incident outside the main axis is refracted when passing through the light exiting surface 33, and the refracted light is refracted. The light is diverged outwards, so that the light is evenly emitted; on the contrary, the lamps of the prior art have equal wall thicknesses. After the light passes through the light-emitting surface, the light at the main axis has a large light intensity, and the light intensity decreases with deviation from the main axis.

The concept of the present invention can be implemented in any kind of light source, such as a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent tube (EEFL), a differential electrode fluorescent tube (DEFL), or a light emitting diode (LED). ), etc., the lamp body is not limited to a triangle. Considering that the backlight of the prior art stage provides better efficiency and better cost structure by using a cold cathode fluorescent lamp, the fourth to fifth figures show a lamp according to another embodiment of the present invention, which is a kind of cold. Cathode fluorescent lamp tube, wherein the fourth picture is a schematic view of the lamp tube, and the fifth figure is a sectional view of the lamp body.

As shown in the fourth figure, the lamp tube 4 includes a hollow and transparent lamp body 41. The first electrode 44 and the second electrode 45 are respectively disposed on the first end 42 and the second end 43 of the lamp body 41 and have a portion. Extending into the lamp body 41, the two covering portions 48 respectively cover and fix the first electrode 44 and the second electrode 45. The lead wires are electrically connected to the first electrode 44 and the second electrode 45, respectively. The cladding portion 48 is provided, the fluorescent material 47 is disposed on the inner surface of the bulb body 41, and the inert gas 46 is sealed to the hollow portion of the bulb body 41.

The shape of the first electrode 44 and the second electrode 45 is not limited to a circular shape or an elliptical shape, and may be other shapes depending on the shape of the hollow portion of the bulb body 41. The covering portion 48 may be made of glass and integrally formed with the bulb body 41. In the embodiment, the bulb body 41 is triangular, and the covering portion 48 is gradually formed by a triangle being drawn into a circular shape. In the example, the covering portion 48 may have other shapes. The phosphor material 47 contains a phosphor or a phosphor, and the type of the phosphor can be determined according to the desired wavelength of the light source. The inert gas 46 is, for example, a fixed ratio of helium to a mixed gas of argon and mercury vapor. When an alternating voltage is applied to the first electrode 44 and the second electrode 45, the lamp body 41 emits electrons from the second electrode 45 to collide with the inert gas 46, the number of electrons increases exponentially, and the inert gas 46 is excited by electrons. Ultraviolet rays are emitted, and the ultraviolet rays collide with the fluorescent material 47 to emit visible light.

The embodiments of the fourth and fifth figures described above are a cold cathode fluorescent lamp (CCFL), but are not limited thereto. Other types of lamp structures, such as external electrode fluorescent tubes (EEFL), differential electrode fluorescent tubes (DEFL), and the like, can be obtained by those skilled in the art via modification.

The sixth graph compares the light energy distribution of the present invention with the prior art. A plurality of conventional "equal wall thickness" lamps are disposed in a light emitting device 50, such as a backlight module, to obtain a light energy distribution. In the same light-emitting device 50, the lamp tube of the present invention having a plurality of "unequal wall thicknesses", such as the lamp of the third or fourth figure, can be obtained by maintaining the same number of lamps and the distance between the lamps and the like. A more uniform distribution of light energy.

The shape of the lamp body of the lamp tube of the present invention is not limited to a triangle. The seventh figure illustrates that the lamp tube of several embodiments includes the lamp body of various shapes: the lamp body 51 is a square or a rectangle; the lamp body 52 is a circle. Shape or elliptical shape; the lamp body 53 is triangular; the lamp body 54 is polygonal or regular hexagon.

The hollow portion of the lamp body of each of the above lamp tube embodiments is not limited to the circular or elliptical shape in the figure, and the formation position of the hollow portion may be asymmetric with respect to the center of the lamp body, but the shape and position of the hollow portion. Cooperating with the shape of the lamp body will determine the average energy distribution of the light exiting the lamp. For convenience of description, the lamp body of any shape, such as the lamp body 51, 52, 53, 54 , the present invention defines a thinnest wall thickness a and a thickest wall thickness b, and a light-emitting surface 55 may be further defined. For better light output intensity, the light exit surface 55 should be orthogonal to the thinnest wall thickness a, which can result in a concave lens exit surface 55 having a thinner central portion and a thicker edge.

In addition, it has been found through experiments that when the ratio of the thickest wall thickness b to the thinnest wall thickness a is approximately 1.1 to 6, that is, 1.1 < b/a < 6, the uniformity of light emission from the lamp is better. The size of the thickest wall thickness b and the thinnest wall thickness a is practically 0.1 to 0.6 mm, but is not limited thereto. Further, the lamp body of the lamp of each of the above embodiments can also be applied to the cold cathode fluorescent lamp of the fourth drawing.

The eighth figure shows the optical simulation results of the conventional "equal wall thickness"; the ninth figure shows the optical simulation results of the "unequal tube wall thickness" of the present invention. The figure shows the illuminance of the x-axis distance (in mm) versus the z-axis distance (in mm), and the luminance unit is watts per square meter (W/m2). As is apparent from the drawings, the difference between the maximum luminance and the minimum luminance of the lamp of the "unequal wall thickness" of the present invention is small and the luminance is relatively average.

The tenth illustration illustrates that the lamp of the present invention can be applied to a backlight module in a liquid crystal display. The backlight module 60 of the following type includes a bottom case 56 having an inner portion 57 in which a plurality of tubes 58 of the unequal wall thickness of the present invention are disposed, and a diffusing material 59 is disposed above the bottom case 56.

The diffusion material 59 may be composed of a plurality of diffusion layers 59 for scattering and diffusing incident light from the lamp 58 to reduce the difference in brightness caused by the difference in lamp position. One or more ridges (not shown) may be placed over the diffusing material 59 to aid in uniform illumination. The inner portion 57 of the bottom case 56 may be provided with a reflecting plate (not shown) for reflecting incident light from the lamp tube 58 to improve the luminous efficiency of the backlight module 60.

In addition, it has been experimentally found that the arrangement of the lamp tubes 58 in the arrangement of the backlight module 60 also affects the luminous efficiency. If the distance between the lamp tube 58 is c and the distance from the lamp tube 58 to the bottom of the diffusion material 59 is d, it is found by experiments that when c/d>1.5, there is better luminous efficiency, and if the thinnest wall thickness of the lamp tube 58 is further matched. a is disposed facing the diffusion material 58, and the luminous efficiency is better.

The eleventh figure illustrates that the lamp of the present invention can be applied to a side-lighting type backlight module in a liquid crystal display. The backlight module 66 is provided with a lamp tube 61 of the "unequal wall thickness" of the present invention on the side (single side or both sides), for example, the lamps of the third, fourth, and seventh embodiments; The reflector 62 surrounds the lamp 61; a light guide 63 converts the light incident from the lamp 61 into a surface light source; a reflector 64 is disposed at the bottom of the light guide plate 63; and a diffusion material 65 is disposed above the light guide plate 63. The diffusion material 65 may be composed of a plurality of diffusion layers 65 for scattering and diffusing light to uniformly emit light. One or more cymbals (not shown) may be placed over the diffusing material 65 to facilitate uniform illumination.

It should be noted that the hollow portion of the "unequal wall thickness" of the present invention can also be used to form a convex surface of a convex lens having a thicker central portion and a thinner edge, which can be considered, for example, when applied to a side-lit backlight module. Such a lamp structure.

The backlight module of the tenth and eleventh figures can be applied to a liquid crystal display device. For example, a liquid crystal panel (not shown) may be disposed above the backlight module 60/66, and includes a color filter substrate and a thin film transistor substrate. The liquid crystal display is filled between the two substrates to form a liquid crystal display device. The thin film transistor substrate electrically controls the liquid crystal according to the video data and adjusts the light emitted by the backlight module 60/66 to form an image.

Thereby, the lamp tube, the backlight module and the liquid crystal display device disclosed by the invention can have better luminous efficiency and brightness, and reduce the cost of the backlight module and the liquid crystal display.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention; all other equivalent changes or modifications which are not departing from the spirit of the invention should be included in the following Within the scope of the patent application.

1. . . Lamp

2. . . Lamp

3. . . Lamp

4. . . Lamp

10. . . Glass tube

12. . . Fluorescent material

14. . . Inert gas

16. . . electrode

18. . . wire

twenty one. . . Glass tube

twenty two. . . Surface electrode

twenty three. . . Fluorescent material

twenty four. . . Inert gas

31. . . Lamp body

32. . . Light

33. . . Glossy surface

41. . . Lamp body

42. . . First end

43. . . Second end

44. . . First electrode

45. . . Second electrode

46. . . Inert gas

47. . . Fluorescent material

48. . . Covering part

49. . . wire

50. . . Illuminating device

51. . . Lamp body

52. . . Lamp body

53. . . Lamp body

54. . . Lamp body

55. . . Glossy surface

56. . . Bottom shell

51. . . internal

58. . . Lamp

59. . . Diffusion material

60. . . Backlight module

61. . . Lamp

62. . . Reflector

63. . . Light guide

64. . . Reflective plate

65. . . Diffusion material

66. . . Backlight module

a. . . Thinnest wall thickness

b. . . Thickest wall thickness

c. . . Lamp spacing

d. . . Distance from the tube to the bottom of the diffusion material

The first and second figures illustrate two conventional lamp structures; the third figure shows a lamp tube according to an embodiment of the present invention; and the fourth to fifth figures show a lamp tube according to another embodiment of the present invention; Comparing the light energy distribution diagram of a light-emitting device after configuring the lamp of the present invention and the prior art; the seventh figure shows the lamp tube of some embodiments of the present invention; the eighth figure shows the optical simulation of the lamp of the prior art; the ninth figure shows The optical simulation of the lamp tube of the present invention; the tenth figure shows the all-in-one backlight module of the embodiment of the present invention; and the eleventh figure shows the one side edge-lit backlight module of the embodiment of the present invention.

3. . . Lamp

31. . . Lamp body

32. . . Light

33. . . Glossy surface

Claims (22)

a lamp tube comprising: a hollow lamp body having unequal wall thicknesses, wherein the light of the lamp is emitted from the inside to the outside by the hollow portion of the lamp body, and the inner wall of the lamp body has a The concave lens of the center is thinner and thicker, and has a convex surface of a convex lens with a thicker central portion and a thinner edge. The lamp of claim 1, wherein the lamp body is made of glass, and the lamp is a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), and a differential electrode fluorescent device. Light tube (DEFL) or light emitting diode (LED). The lamp tube of claim 1, wherein the lamp body comprises a first end and a second end, the lamp tube further comprising: a first electrode disposed on the first end of the lamp body; The two electrodes are disposed on the second end of the lamp body; and the two wires are electrically connected to the first electrode and the second electrode, respectively. The lamp of claim 1, wherein the fluorescent material is disposed on an inner surface of the hollow portion of the lamp body; and An inert gas is sealed to the hollow portion of the lamp body. The lamp of claim 4, wherein the fluorescent material comprises a phosphor or a phosphor. The lamp of claim 3, wherein a portion of the first electrode extends into the lamp body, and a portion of the second electrode extends into the lamp body. The lamp tube of claim 3, further comprising two covering portions respectively covering the first electrode and the second electrode, wherein the two wires respectively extend out of the two covering portions. The lamp of claim 7, wherein the two cladding portions are made of glass material and integrally formed with the lamp body. The lamp of claim 3, wherein the lamp body has a shape of one of a square, a rectangle, a diamond, a circle, an ellipse, a triangle, a polygon, and a regular hexagon. The lamp of claim 3, wherein the shape of the first electrode and the second electrode is circular or elliptical or fits the shape of the hollow portion of the lamp body. The lamp of claim 3, wherein the hollow portion of the lamp is disposed asymmetrically to the center of the lamp body. The lamp of claim 3, wherein the configuration of the hollow portion of the lamp is symmetric to the center of the lamp body. The lamp of claim 3, wherein the concave surface of the concave lens comprises a thinnest wall thickness of thickness a and a thickest wall thickness of thickness b, wherein the thinnest wall thickness is in a direction perpendicular to the light exit surface of the concave lens. . The lamp of claim 13, wherein the ratio of the thickness b of the thickest wall thickness to the thickness a of the thinnest wall thickness is substantially between 1.1 and 6, that is, 1.1 < b/a < 6. The lamp of claim 13, wherein the thickness b of the thickest wall thickness and the thickness a of the thinnest wall thickness are approximately 0.1 to 0.6 mm. A backlight module includes: a bottom case; a plurality of lamps are disposed on the bottom case, wherein each of the lamps comprises a lamp body having unequal wall thicknesses, and each of the lamp bodies The inner wall has a concave lens emitting surface with a thinner central portion and a thicker edge; and a diffusion material is disposed above the plurality of lamps. The backlight module of claim 16, wherein the bottom of the bottom case is further provided with a reflecting plate for reflecting light from the plurality of lamps. The backlight module of claim 16, wherein the lamp spacing of the plurality of lamps is defined as c, the distance between the tube and the diffusion material is defined as d, and c/d>1.5. A backlight module includes: a light guide plate; a light tube disposed on one side of the light guide plate, the light tube includes a lamp body having a thickness of the pipe wall, and the lamp body of the lamp tube The inner wall has a convex lens emitting surface with a thicker central portion and a thinner edge; a reflector surrounds the tube; and a diffusion material is disposed above the light guide plate. The backlight module of claim 19, further comprising a reflector disposed at the bottom of the light guide plate. A liquid crystal display device comprising: a liquid crystal panel; and a backlight module, such as the backlight module of claim 16 of the patent application. A liquid crystal display device comprising: a liquid crystal panel; and a backlight module, such as the backlight module of claim 19 of the patent application.