CN100460960C - Ribbon light source generating device and its application - Google Patents

Abstract

The invention discloses a strip-shaped light source generating device and its application. The strip-shaped light source generating device includes a light guide body and at least one light-emitting source. The light guide body is a cylindrical body made of light-transmitting materials. The surface of the light guide body is provided with at least one diffusion strip, and the other side of the diffusion strip is a circular light-emitting surface; one end surface of the light guide body is covered with a reflective film and defined as a reflection surface, and the opposite end is an incident surface , the light emitting source is arranged on the incident surface of the light guide. Combining a plurality of strip light sources of the present invention side by side to form a surface light source can provide sufficient and uniform directional light, so optical films such as diffusion films or prism sheets can be omitted, and, due to low light loss, longer The light guide can also obtain evenly distributed light sources, making the present invention more suitable for large-size liquid crystal panels.

Description

Ribbon light source generating device and its application

technical field

The invention relates to a light source device and its application, in particular to a strip light source device for generating directional light and its application.

Background technique

Liquid crystal display (LCD) has the advantages of low power consumption, low radiation, thin thickness, light weight, etc., and has gradually replaced the traditional picture tube display, and has become a widely used flat-panel display. The liquid crystal display itself is a non-self-illuminating display device, and it must rely on an external light source to achieve the display effect. The current liquid crystal display system uses a backlight module (Backlight) as an external light source, and the performance of the backlight module light source will directly affect the liquid crystal display. The display quality of the monitor.

The existing backlight module is composed of light source, light guide plate, diffuser, prism sheet, reflector and other components, according to the layout of the light source in the backlight module The position can be divided into side-edge type and direct type. The side-light type light source is installed on the side of the backlight module. After the light enters the light guide plate from the side, it passes through the exclusive design of the light guide plate. The reflective stripes turn the light into the LCD liquid crystal display evenly, and the liquid crystal display using the side light source is mostly used in small portable electronic devices such as notebook computers and personal digital assistants; the direct light source is set on the LCD panel. At the bottom, the light is directly or indirectly reflected to the upper optical film to increase brightness. Liquid crystal displays using direct light sources are mostly used in large-size displays such as LCD TVs.

The backlight module generally uses a cold cathode fluorescent lamp (Cold cathode fluorescent lamp, CCFL) as a light source. The cold cathode fluorescent lamp is a long and thin sealed glass tube filled with inert gas, and mercury is used as a discharge medium. When the voltage is high, the inert gas generates ultraviolet rays and excites the fluorescent material on the inner wall of the lamp tube to emit visible light; cold cathode fluorescent lamps have the advantages of low cost and high efficiency (ratio of light output to input electric power), but cold cathode fluorescent lamps need There is a high driving voltage, and the cold cathode fluorescent lamp has temperature dependence, which is not conducive to starting at low temperature. Moreover, the mercury contained in the cold cathode fluorescent lamp will cause harm to the environment and the human body. Therefore, how to obtain an alternative cold cathode fluorescent lamp The light source of the tube has become the subject of research and development by backlight module manufacturers.

In recent years, the technology of light-emitting diodes (LEDs) has become more and more mature. Light-emitting diodes have the characteristics of low driving voltage, long life and high power saving, and can be made into miniaturization or arrays to meet the needs of applications, such as transportation The application of light-emitting diodes can be seen in signal signs, billboards, flashlights and various electronic product indication lighting, making light-emitting diodes a widely used light source. Therefore, replacing cold cathode fluorescent tubes with light-emitting diodes has become the main focus of backlight module manufacturers research direction. US Patent No. US 5727862, US 5769521, US 5786665, US 5883684, US 6036328, US 6065845, US 6139163, US 6375335, US 6386720, US 6419372, US 6474806, US 65 No. US 6520655, US 6521879, US 6582095, US 6969189 and US 6608614 respectively disclose a plurality of technical solutions using light-emitting diodes as the light source of the backlight module. These technical solutions can also be divided into side-light type and direct-light type. However, no matter it is side-lit or direct-lit, LEDs are only used to replace cold-cathode fluorescent tubes, and the light emitted must be the same as the backlight module of cold-cathode fluorescent tubes. The light is injected into a light guide plate, which is about a square plate (wedge or flat plate) matching the area of the liquid crystal panel. The light is reflected from the reflector to the top of the light guide plate to emit light. The light guide plate has an optical film (diffusion film, prism) film, brightness enhancement film, etc.), through the optical film to obtain a uniform surface light source.

In the above-mentioned U.S. patent, no matter it is a side-light type or a direct-light type, multiple light-emitting diodes must be used, and then the point light source is coupled into a surface light source. Therefore, the surface light source cannot be evenly distributed; Variations in intensity and distribution, the general backlight module design can only consider the uniformity of light, and cannot take into account the requirements of light distribution, light directivity, light efficiency, polarization, etc., so it is necessary to add a lot of extra diffusers, prisms (Prism sheet), Brightness enhancement sheet (Enhance sheet), Reflector (Reflector) and other optical films to adjust their optical properties to meet the needs of liquid crystal panel applications. In order to apply to the backlight of large-sized liquid crystal panels, the use of direct-type backlight modules often requires hundreds or even thousands of light-emitting diodes to be arranged in a high-density matrix to achieve uniformity within a short distance. The more light-emitting diodes are used, although the uniformity of light output can be improved, the manufacturing cost will also increase, and the point light source will cause serious light loss through multiple couplings of light guide plates and multi-layer optical films, which will increase relatively. The power consumption of the backlight module, therefore, there are still many problems to be solved when applying light emitting diodes to the backlight module.

U.S. Patent No. US 5969343 discloses a linear lighting device applied to image scanners. In order to solve the problem of uneven light caused by traditional linear light sources with multiple LED arrays, a cylindrical guide and A linear light source device composed of a light emitter, the cylindrical guide is made of light-transmitting material, and a light scattering part is provided on a part of the side of the cylindrical guide, and the light emitter is arranged on an end surface of the cylindrical guide , the light emitted by the light emitter enters the interior of the cylindrical guide through the end face, and the light travels inside the cylindrical guide and is continuously reflected by its side. When part of the light enters the light scattering part, part of the light is scattered. Scattered light with an incident angle smaller than the critical angle relative to the side of the cylindrical guide will enter the air and become illumination light. The light-scattering part of the cylindrical guide part of the linear lighting device disclosed in the 343 case scatters the total reflected light, scatters the light incident therein to the air, and obtains the radiated light in the main scanning direction, which is applied to a scanner , can improve the problems caused by the linear light source of the traditional scanner array, but the linear lighting device disclosed by it, the incident light is scattered in the air, so the emitted light has no directivity, and cannot be used as a backlight light source of the liquid crystal panel .

U.S. Patent No. US 20050270796 discloses a planar light source device and its display device. The purpose of the invention is to improve the uneven luminance of traditional LED lamp tubes and the volume of light guide plates. The disclosed planar light source device consists of a frame, a light source unit, Composed of light guide rods and reflectors, a number of light guide rods made of transparent materials such as resin or glass are arranged parallel to each other in the frame, and a point-shaped light source is arranged on one end of each light guide rod, and the frame body The inner bottom surface is equipped with a reflector, which reflects the light emitted by the light source unit (point light source and light guide rod) to the light emitting surface of the frame; and the light source unit injects the light emitted by the point light source into the light guide rod from the end surface The light in the light guide rod is refracted on the end face, because the angle with the exit surface of the light guide rod becomes more than the critical angle, it is totally reflected on the exit surface, and propagates toward the opposite end face of the light guide rod. The included angle of the emitting surface of the light rod is below the critical angle, so the light on the emitting surface of the light guide rod will not be totally reflected, but the light on the emitting surface near the point light source will increase. The disclosed planar light source device uses a plurality of light guide rods and point light sources as the light source unit, and the light emitted by the light source unit is reflected to the light emitting surface of the frame through the reflection plate below. This patent can also provide relatively uniform light, but The design of its frame and reflector actually increases the volume of the backlight module; moreover, the light guide bar only means that the angle between the incident light and the exit surface is below the critical angle, and it will not be completely visible on the exit surface of the light guide bar. reflection, and does not propose how to obtain uniform or directional light, therefore, it is still not possible to implement it as a backlight source for a liquid crystal panel.

Contents of the invention

The object of the present invention is to overcome the defects of the prior art and provide a directional and evenly distributed strip light source generating device.

The purpose of the present invention is achieved through the following technical solutions: including at least one light source and a light guide body, the light guide body is a cylindrical body made of light-transmitting material, and the surface of the light guide body is provided with at least A diffuser strip, opposite to the diffuser strip, is a circular light-emitting surface; one end surface of the light guide body is covered with a reflective film and defined as a reflective surface, and the opposite end is an incident surface, and the light-emitting source Set on the incident surface of the light guide.

The light generated by the light-emitting source enters the interior of the light guide body from the incident surface and undergoes total reflection. The light continuously undergoes total reflection inside the light guide body. , will scatter a ray of light into multiple scattered rays towards multiple angles, the scattered ray will hit the light-emitting surface of the arc, and the light-emitting surface of the arc will refract the scattered ray in the direction relative to the diffuser bar, so that the scattered ray Converging and emitting out of the light guide body, it becomes a directional and uniformly distributed strip light source.

The following are the preferred options:

The reflective surface of the light guide is also equipped with a light source;

The diffuser strip has an axial grating in fine striations;

or the diffuser strip has a sagittal grating in fine stripes;

The diffusion strips can also be in a regular or irregular intermittent discontinuous shape;

One side of the surface of the light guide body is provided with two diffusion strips correspondingly deviated from the normal line and having the same angle, the light generated by the light source is totally reflected inside the light guide body, and the light rays hit the The diffusing strips intersect and scatter each other, and the scattered light is refracted through the light-emitting surface to converge and stagger to emit light.

The belt-shaped light source generating device of the present invention injects a point light source into the light guide body for total reflection, the light is continuously reflected in the light guide body without loss of luminous flux, and the totally reflected light hits the diffuser strip repeatedly and passes through the light guide The light-emitting surface of the body arc refracts and gathers the light to produce a directional and uniformly distributed strip-shaped light source.

The present invention is actually applied to the backlight light source of the liquid crystal panel. A surface light source is formed by combining multiple strip light sources in parallel, which can provide sufficient and uniform directional light, so that the configuration of optical films such as diffusion films or prism sheets can be omitted, and According to different sizes of LCD panels, you can choose a light guide with a matching length. Due to the low light loss, a longer light guide can also obtain a uniformly distributed line light source, and the polarization characteristics of the light controlled by the diffuser strip are effectively increased. The efficiency of light entering the liquid crystal panel makes the present invention more suitable for large-size liquid crystal panels.

Using the present invention as a light source for a backlight module of a liquid crystal display can obviously improve the display quality, high brightness and high uniformity of the liquid crystal display.

The strip-shaped light source generating device of the present invention can be preferably used as a backlight source of a liquid crystal display, but is not limited to be used as a backlight source of a liquid crystal display, such as indoor and outdoor lighting sources, vehicle light sources, etc. can be applied.

Description of drawings

Fig. 1 is a schematic diagram of the structural composition relationship of the first embodiment of the present invention;

Fig. 2 is a schematic diagram of another perspective view of the structural composition of the embodiment shown in Fig. 1;

Fig. 3, 4, 5 are the schematic diagrams of the structural composition optical relationship of the embodiment shown in Fig. 1;

6A and 6B are schematic diagrams of a first application example of the first embodiment;

Fig. 7 is a schematic diagram of another aspect of the diffusion strip in the first application example of the first embodiment;

8A and 8B are schematic diagrams of a second application example of the first embodiment;

Fig. 9 is a schematic diagram of the structure and composition of the second embodiment of the present invention;

10A and 10B are schematic diagrams showing the structure-optical relationship of the third embodiment of the present invention;

Fig. 11 is a schematic diagram of the structure and composition of the fourth embodiment of the present invention.

In the figure: 10, light guide body, 10a, incident surface, 10b, reflective surface, 11, reflective film, 12, diffusion strip, 13, light emitting surface, 20, light source, 30, light guide plate

Detailed ways

The present invention will be further described below in conjunction with drawings and embodiments.

Example 1

With reference to Fig. 1, 2, present embodiment is made of a light guide body 10 and a luminous source 20; Light guide body 10 is the cylinder made of transparent material, and wherein transparent material system is optical acrylic (Polymethyl methacrylate, PMMA ) or glass and other materials, one end surface of the light guide body 10 is defined as the incident surface 10a, and the opposite end surface is defined as the reflective surface 10b, and the reflective surface 10b is covered with a reflective film 11. The light with an angle greater than the critical angle will be totally reflected without loss of luminous flux, and the light will also be incident on the reflective film 11 of the reflective surface 10b for specular reflection. Inside the light guide 10.

On the circumferential surface of the light guide body 10, a diffusion strip 12 is arranged along the axial direction parallel to the light guide body 10, the diffusion strip 12 is perpendicular to the normal line of the light guide body 10, and the diffusion strip 12 is formed as two The printing paint of high divergence light source material such as silicon oxide (SiO ₂ ), titanium dioxide (TiO ₂ ) is directly coated on the peripheral surface of light guide body 10, or a high divergence light source material is pasted on the surface of light guide body 10, or Alternatively, a fine striped grating structure (Texture) can be formed on the surface of the light guide body 10 . In order to realize a directional and uniformly distributed strip-shaped light source, the diffusion strip 12 is preferably coated with printing paint directly on the light guide body 10, and the number, wide distance to obtain the desired light distribution of the directional strip light source.

The other surface of the light guide body 10 relative to the diffuser strip 12 is defined as a light exit surface 13 , and the light exit surface 13 is formed by the cylindrical surface of the light guide body 10 and is an arc surface.

The light source 20 is a self-illuminating component that can emit light such as a light emitting diode. The light source 20 is arranged on the incident surface 10a of the light guide body 10. It can be closely attached to or embedded in the incident surface 10a of the light guide body 10. There is a gap with the incident surface 10a, which can be designed according to the actual spatial structure relationship to obtain the required optical requirements.

As shown in Figures 3, 4, and 5, the light source 20 emits light from the incident surface 10a and enters the light guide 10. When the light is transmitted in the light guide 10, when the incident angle of the light is greater than the critical angle, the light is completely The light cannot be emitted to the light guide body 10, so that the light rays are continuously totally reflected inside the light guide body 10, so that the light rays are evenly filled inside the light guide body 10 (as shown in FIG. 3 ). When a ray of continuous total reflection hits the diffuser strip 12, it will scatter a ray into multiple scattered rays towards multiple angles. When the incident angles of these scattered rays are all smaller than the critical angle of total reflection , part of the light passes through the light guide 10 from the light-emitting surface 13 (as shown in Figure 4); and the incident angle of the scattered light is still greater than the light of the critical angle of total reflection and continues to reflect until it hits the diffuser strip 12 and Repeat its scattering process. The light of the light source generating device, in addition to being emitted from the light-emitting surface 13 of the light-guiding body 10 as shown in FIG. The light emitting surface 13 of the body 10 (as shown in FIG. 5 ) becomes a strip-shaped light source with directivity and uniform distribution.

Referring to Fig. 6A, 6B, what is shown in the figure is the first application example of the above-mentioned embodiment of the present invention. For example, as a backlight source for a liquid crystal display (not shown in the figure), multiple strip light source generating devices of this embodiment are arranged side by side as a direct-type backlight module (as shown in FIG. 6A ), and different diameters are used according to different optical requirements. The light guide body 10, and the distance between each light source generating device is properly set, and a plurality of strip-shaped light sources are assembled into a large-scale surface light source, and a uniform light distribution as shown in Figure 6B can be obtained, so as to provide sufficient and Uniform directional light is used as the backlight source, so optical films (not shown) such as diffusion film or prism sheet can be omitted, thereby simplifying the manufacturing process of the liquid crystal display and reducing the manufacturing cost. At the same time, the light guide body 10 of matching length can be selected according to the liquid crystal panels of different sizes. Due to the low luminous flux loss, the longer light guide body 10 can obtain uniformly distributed line light sources, making the present invention more suitable for large-sized liquid crystals. on the monitor.

Referring to Figures 7A and 7B, it shows another form of the diffusion strip 12 in the first application example of the first embodiment of the present invention, where the light guide body 10 is pre-rolled at the position where the diffusion strip 12 is to be coated. After the axial or sagittal fine stripes are extruded, the printing paint of the high-divergence light source material is coated on the stripes to form a strip-shaped axial grating 121 (as shown in FIG. 7A ) Or the sagittal section grating 122 (as shown in FIG. 7B ), the width and spacing of the axial grating 121 or the sagittal section grating 122 can control the polarization characteristics of scattered light, so as to effectively increase the efficiency of light entering the liquid crystal panel.

8A, 8B, shown in the figure is the second application example of the first embodiment of the present invention. In the known technology, the side-lit backlight module either uses cold-cathode fluorescent tubes as side light sources or multiple light-emitting diodes as side light sources. For the light source, since the light emitted by it is not directional, the light guide plate must use a wedge-shaped light guide plate, but the wedge-shaped light guide plate is difficult to manufacture. And the strip-shaped light source generating device of the present invention can also be applied to the side-light type backlight module, wherein the strip-shaped light source generating device is arranged on the light guide plate 30 of the side-light type backlight module, because the light emitted by the strip-shaped light source generating device has a directional Therefore, the light guide plate 30 can be a square plate made of general optical acrylic, and the highly directional light emitted from the light-emitting surface 13 of the light guide body 10 enters the light guide plate 30 more efficiently, which can replace the known cold cathode fluorescent tubes or multiple LED side light sources.

Example 2

Referring to FIG. 9 , in this embodiment, the reflective film 11 is not attached, but another light source 20 is arranged on the reflective surface 10 b to increase the brightness of the light.

Example 3

Referring to Figures 10A and 10B, in this embodiment, the width or position of the diffusion strip 12 can be changed according to different optical requirements, so as to change the range and directivity of the light output, and multiple diffusion strips 12 can also be added according to the optical requirements. As shown in the figure, two diffusion strips 12 correspondingly deviated from the normal line are arranged on the light guide body 10, and the two diffusion strips 12 have the same angle with respect to the normal line, and the light totally reflected in the light guide body 10, Respectively irradiated to the two diffuser strips 12 to scatter, because of the relationship between the relative angles of the diffuser strips 12, the scattered light rays are interlaced with each other, and the scattered light rays are gathered together through the light-emitting surface 13 to interleave the light, and the interlaced light rays will converge with each other, so that The luminance and uniformity are improved (see FIG. 10B ), and the directional light emission increases the black-white contrast value of the liquid crystal display, which is suitable for large-size liquid crystal displays.

Example 4

Referring to Fig. 11, in this embodiment, as shown in the figure, the scattering strip 12 can be coated as intermittent regular or irregular discontinuous lines, so that the range of light output can also be controlled, and it can be used for different optical requirements to save money. Light energy simplifies the design of the shading mechanism.

The several preferred embodiments of the present invention described above can be used not only as a backlight light source for liquid crystal displays, but also as a light source for indoor and outdoor lighting, and a light source for vehicles.

The above descriptions are only some preferred embodiments of the present invention, and these embodiments shall not be used to explain the limitation of the patent protection scope of the present invention. All equivalent changes or modifications made according to the scope of the patent application of the present invention belong to the protection scope of the patent of the present invention.

Claims (5)

1. band light source generation device, include a light conductor and at least one light emitting source, described light conductor is the cylinder that is made with light transmissive material, it is characterized in that, described light conductor surface one side is provided with two corresponding off-normal and has the diffusion bar of identical angle, is the exiting surface that is circular arc with respect to this diffusion bar opposite side; A be covered reflectance coating and be defined as reflecting surface of described light conductor one end face, a relative end is the plane of incidence, described light emitting source is arranged at the plane of incidence of light conductor.

2. band light source generation device as claimed in claim 1 is characterized in that, described diffusion bar has the axial grating that is trickle striped.

3. band light source generation device as claimed in claim 1 is characterized in that, described diffusion bar has the arrowhead grating that is trickle striped.

4. as claim 1 or 2 or 3 described band light source generation devices, it is characterized in that described diffusion bar is rule or the discontinuous shape of irregular interruption.

5. as the application of the described band light source generation device of one of claim 1-4 in LCD, it includes many light conductors that are set up in parallel, the light that each light emitting source produced carries out total reflection in the inside of this light conductor respectively, light is mapped to this light conductor diffusion bar and carries out scattering, scattered beam converges bright dipping through this exiting surface refraction and forms a band light source, and the band light source of each light conductor is formed an area source.

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