JP3813145B2 - Optical structure and polarizer - Google Patents

Description

  The present invention relates to an optical structure, and more particularly to an optical structure for a panel display.

  With the rapid development of digital technology, panel displays have become a key element for many electronic devices such as: Examples of the electronic device include a notebook PC, a mobile phone (mobile phone), an information device (IA), and a personal digital assistant (PDA). In general, brightness, thinness, and / or low power consumption are basic requirements for a typical panel display.

  However, narrowing of the viewing angle, brightness problems, high image quality, stability against temperature, and related matters are still under development for improvement of panel display technology.

  Liquid crystal displays have been developed as a new panel display technology due to the following remarkable characteristics. Its characteristics are excellent brightness, clear image quality, wide viewing angle, quick response, simple manufacturing process, and low energy consumption.

Thus, LCDs have been actively researched and improved by producers and become popular products.

  Please refer to Fig.1. This shows the structure of the current transmission type liquid crystal display. As shown in FIG. 1, since the liquid crystal molecules themselves cannot emit light, it is necessary to dispose the backlight module 10 on the back of the panel display in order to secure the necessary light quantity.

  The backlight module 10 usually includes at least one fluorescent lamp tube or a light source 101 such as a light emitting diode (LED), which is built in or disposed on both sides.

  The white light 11 sent out from the light source 101 of the backlight module 10 through the light guide plate, the reflection plate, and the dispersion plate is uniformly radiated from the surface of the backlight module 10, and the lower deflector 12, the glass substrate 13, and the liquid crystal Passing through the layer 14, the color filter 15, and the upper deflector 16, an image is formed.

  In other words, the liquid crystal display sequentially transmits the white light 11 radiated from the backlight module 10 through the lower deflector 12, the glass substrate 13, and the liquid crystal layer 14, and bends the incident light to a certain angle (the phase angle is changed). To change).

  On the other hand, the arrangement of liquid crystal molecules in the liquid crystal display can be changed by adjusting the voltage between the indium tin oxide (ITO) films 17.

  Thereafter, the incident light needs to further pass through the color filter 15 and the upper deflector 16. This is because the polarized light between the upper deflector 16 and the lower deflector 12 has a phase angle difference of 90 degrees, so that the first incident light is blocked and shielded.

  However, since the liquid crystal layer 14 can bend incident light by adjusting the voltage between the indium tin oxide (ITO) film 17, the intensity and color tone of the emitted light can be adjusted between the indium tin oxide (ITO) film 17. Can be controlled. In this way, different light color combinations can be displayed on the liquid crystal display.

  Regarding the LCD, the backlight module 10 and the deflectors 12 and 16 are important optical devices. The background of these devices will be described below.

  Please refer to Figure 2. This shows the structure of the current deflector. As shown in FIG. 2, the current deflector consists of the following elements. That is, it consists of the surface protective layer 21, the first protective layer 22, the polarizing layer 23, the second protective layer 24, the adhesive layer 25 and the release film 26.

  The polarizing layer 23 is made of polyvinyl alcohol (PVA), which has a polarizing form that serves as a polarizing substrate. When the PVA is stretched, the mechanical properties of the PVA deteriorate and the polarizing layer becomes brittle.

  Thus, when PVA is stretched for film formation, both sides of the PVA are coated with protective layers 22, 24, such as triacetyl cellulose (TAC), to protect the PVA film and prevent wrinkles. The

  Furthermore, in addition to the first protective layer 22 and the second protective layer 24, a surface protective layer 21 and a release film 26 may be added in order to protect the deflector during storage and transportation.

  In general, normal light sources are multi-directional (non-polarized), LCD deflectors act as optical filters, which keep the light in a specific direction (ie, polarized unpolarized light is polarized) Exclude light that is not in a specific direction (converted out).

  An LCD typically includes an upper deflector and a lower deflector, in which light polarized by the two deflectors has a phase angle of approximately 90 degrees.

  Therefore, light that has passed through the first deflector cannot pass through the second deflector.

  If the liquid crystal molecules of the liquid crystal layer intervene between the two deflectors and the polarized light is swirled so that it is bent 90 degrees, then this polarized light is converted into the second deflector. Will be able to pass through.

  However, if the liquid crystal layer is bent in the same direction as the polarized light from the first deflector, then this polarized light may pass through the second deflector. Can not.

  Therefore, the brightness of the light on the panel display can be adjusted by voltage changing means for controlling the turning angle of the liquid crystal molecules.

  Regarding the backlight module 10 element, the backlight module 10 includes a light source, a light guide plate, a reflection sheet, a dispersion sheet, and a brightness enhancement sheet.

  In the current technology, the light source of the backlight module may be a fluorescent lamp tube or a light emitting diode (LED), but in order to harmonize with the development of LCD lightening (slim and light) trend The lighter and thinner backlight module 10 has become the main focus (key part) of recent research and development.

  Therefore, the light source of the backlight module is replaced with an LED, and high luminance, long life, high reliability, and low cost are achieved.

  Desirably, LEDs have recently evolved to have a number of types: red, orange, yellow, green yellow, green, blue, and white.

  Thus, the LED has been regarded as an optimum element as a light source for the backlight module, and has become an indispensable element for manufacturing a backlight module for a panel display.

  Please refer to Fig. 3 (a) and Fig. 3 (b). Each of these shows a backlight module that uses the desired LED as two types of light sources. As shown in FIG. 3A and FIG. 3B, the LED 31 is disposed on one side of the light guide plate 32.

  Light emitted from the LED 31 is transmitted through the light guide plate 32, the reflection plate 33, the dispersion plate 34, or the brightness enhancement plate 35, and is evenly emitted from the surface of the backlight module.

  In manufacturing a normal size TFT-LCD display, a white LED is usually employed as a light source.

  In the prior art, the method of making a white light LED is that the light emitting chip is embedded in the groove of the electrode frame, the color tone of the light emitting chip is mixed, and the light color from the fluorescent powder is changed to white light. At least one layer of fluorescent powder is coated.

  For example, a red light emitting chip coated with blue and green fluorescent powder will be white light (results), and a blue light emitting chip coated with yellow fluorescent powder will be white light.

  Therefore, considering the luminous efficiency and lifetime of the LED, the white light LED sold by NICHIA Company will be the only type of LED element that can be used.

  However, the lifetime and cost of this white light LED is not the same as that of red, green and yellow LEDs, and using this white light LED will shorten the lifetime of the panel display and increase the cost of the panel display. Let's go.

  Accordingly, there is a need to provide an optical structure for panel displays that can be easily and efficiently manufactured.

Furthermore, there is also a need to provide an optical structure that is inexpensive to manufacture, overcomes these difficulties, and eliminates the above problems.
1931 chromatility diagram of International Commission on Illumination (CIE)

  It is an object of the present invention to provide an improved light structure for a panel display, which replaces a conventional backlight module that provides only white color, thereby providing a panel display. It extends the life and reduces costs.

  Another object of the present invention is to provide an optical structure for a panel display, in which an LED having several colors other than white is used as a light source of a backlight module, and white due to the influence on the color of the fluorescent layer. Or it provides light of other mixed colors.

  Accordingly, it is an object of the present invention to provide an improved light structure for a panel display, which replaces a conventional backlight module that provides only white color, thereby providing a panel display. It extends the life and reduces costs.

  The polarizer of the present invention has at least one fluorescent layer excited by the first light of the first color, and when the layer is excited by the first light, the white second Or the mixed light of the second color.

  The polarizer is the upper or lower polarizer of the panel display. The upper and lower polarizers each have a polarizing layer and a surface protective layer, and a fluorescent layer is interposed between the polarizing layer and the surface. The polarizer further has at least one protective layer for protecting the fluorescent layer. In one embodiment, the light source is a light emitting diode (LED) device and the panel display is a low temperature polysilicon (LTPS) thin film transistor liquid crystal display (TFT-LCD).

  In another embodiment, if the color of the first light is red, the polarizer has green and blue fluorescent layers, and when the fluorescent layer is excited with the first light, the second light In white or mixed light in a second color.

  In another embodiment, if the color of the first light is green, the polarizer has red and blue fluorescent layers, and when the fluorescent layer is excited by the first light, the second light In white or mixed light in a second color.

  In yet another embodiment, if the color of the first light is blue, the polarizer has a yellow fluorescent layer, and when the fluorescent layer is excited with the first light, the second light is emitted. White or mixed light is generated in the second color.

  In yet another embodiment, the polarizer has an adhesive layer, a plurality of protective layers, a polarizing layer, and a surface protective layer.

  The present invention provides a polarizer for a panel display, the polarizer having at least one fluorescent layer, which is excited by the emitted light of a non-white LED and is white for a panel display. Alternatively, light of the second color is generated. In the present invention, white light is generated for a panel display using a non-white LED, and the lifetime of the panel display is extended and its cost is reduced. Thus, the present invention is used in the industry and has a great effect. It is.

  FIG. 4 shows a first embodiment of the optical structure of the present invention, which includes a backlight module 40 and a polarizer 41. The non-white light source 401 of the backlight module 40 generates required light. The other light guide plates, reflection sheets, dispersion sheets, brightness enhancement sheets, prism sheets, and the like are the same as those in the prior art, and thus description thereof is omitted.

  Further, the polarizer 41 includes an adhesive layer 411, a first protective layer 412, a polarizing layer 413, a second protective layer 414, a surface protective layer 415, and the like in addition to one or more fluorescent layers. Since these are all the same as those of the prior art, description thereof is omitted.

  In one embodiment of the backlight module 40, the light source 401 is a red LED. According to 1931 chromaticity of International Commission on Illumination (CIE), white light for panel display can be formed by mixing red light, green light and blue light.

  Further, an adhesive layer 411, a first protective layer 412, a polarizing layer 413, a second protective layer 414, a surface protective layer 415, a green fluorescent layer 421, and a blue fluorescent layer 422 are added to the polarizer 41 to form a light mixing device. . The protective layer 423 is added on the blue fluorescent layer 422 to protect the green and blue fluorescent layers 421 and 422.

  The second light of the mixed color is formed by the following steps. First, the red light 42 provided by the light source 401 passes through the light guide plate, the reflection plate, the dispersion sheet, the prism sheet, and the like and is uniformly emitted from the surface of the backlight module 40.

  Next, the red light 42 passes through the adhesive layer 411 and the first protective layer 412 of the polarizer 41, passes through the green fluorescent layer 421 and the blue fluorescent layer 422, excites its own fluorescent powder, and mixes light. White light 43 is generated by the effect.

  Thereafter, the white light 43 passes through the second protective layer 423, reaches the polarizing layer 413, and is polarized. Finally, white polarized light 44 passes through the second protective layer 414 and the surface protective layer 415 and is emitted for use in a panel display.

  FIG. 5 shows a second embodiment of the optical structure of the present invention. The backlight module 40 uses a green LED as a light source 401. According to the CIE, red light, green light, and blue light are mixed to form white second light for panel display.

  Further, an adhesive layer 411, a first protective layer 412, a polarizing layer 413, a second protective layer 414, a surface protective layer 415, a red fluorescent layer 424 and a blue fluorescent layer 425 are added to the polarizer 41 to form a light mixing device. To do. A protective layer 423 is added on the blue fluorescent layer 425 to protect the red fluorescent layer 424 and the blue fluorescent layer 425.

  The second light of the mixed color is formed in the next step. First, the green light 42 from the light source 401 passes through the light guide plate, the reflection plate, the dispersion sheet, the prism sheet, and the like, and is uniformly emitted from the surface of the backlight module 40.

  Next, the green light 42 passes through the adhesive layer 411 and the first protective layer 412 of the polarizer 41, enters the red fluorescent layer 421 and the blue fluorescent layer 422, excites the fluorescent powder, and produces white light by the light mixing effect. 43 is generated.

  Thereafter, the white light 43 passes through the second protective layer 423 and enters the polarizing layer 413 to perform the polarization process. Finally, the white polarized light 44 passes through the second protective layer 414 and the surface protective layer 415 and is emitted for use in the panel display.

  FIG. 6 shows a third embodiment of the optical structure of the present invention. The backlight module 40 has a blue light source 401 that provides blue light 42. By the CIE, blue and yellow are mixed to form white second light for panel display. Furthermore, an adhesive layer 411, a first protective layer 412, a polarizing layer 413, a second protective layer 414, a surface protective layer 415, and a yellow fluorescent layer 426 are added to the polarizer 41 to form a light mixing device. A protective layer 423 may be added on the yellow fluorescent layer 426 to protect the layer.

  In the third embodiment, the second light of the mixed color is formed by the following steps. First, the blue light 42 is provided by the light source 401, passes through the light guide plate, the reflection plate, the dispersion sheet, the prism sheet, and the like, and is uniformly emitted from the surface of the backlight module 40. Next, the blue light passes through the adhesive layer 411 and the first protective layer 412 of the polarizer 41 and enters the yellow fluorescent layer 426, and excites the fluorescent powder to generate white light 43 by the light mixing effect. Thereafter, the white light 43 passes through the protective layer 423 and enters the polarizing layer 413 to perform a polarization process. Finally, the white polarized light 44 passes through the second protective layer 414 and the surface protective layer 415 and is emitted for the panel display.

  In the above embodiment, red LED, blue and green are described as the most practical embodiments, but the present invention is not limited to this. According to the CIE, it can be seen that the emission color of the LED determines the color of the mixed fluorescent layer or changes the design of the polarizer, thereby generating white light or mixed color light (of the color specified by light mixing).

  Furthermore, while the optical structure of the present invention can be applied to all types of panel displays, a low temperature polysilicon (LTPS) thin film transistor liquid crystal display (TFT-LCD) is the best choice. The polarizer 41 may be a lower polarizer of a panel display. Substrates for top polarizers and other panel displays are also contemplated.

It is a cross-sectional side view which shows the structure of the conventional transmissive liquid crystal display. It is a cross-sectional side view which shows the structure of the conventional polarizer. It is a perspective view which shows an example of the backlight module which has LED as a light source. It is a side view which shows the other example of the backlight module which has LED as a light source. 1 is a cross-sectional side view of a first embodiment of an optical structure for panel display according to the present invention. It is a cross-sectional side view of 2nd Example of the optical structure for panel displays of this invention. It is a cross-sectional side view of the 3rd Example of the optical structure for panel displays of this invention.

Explanation of symbols

40: Backlight module 41: Polarizer 42: Red light 43: White light 44: White polarized light 401: Light source

Claims (20)

  A backlight module having a light source that provides a first light of a first color and a white light or a mixed light of a second color when the fluorescent layer is excited by the first light. A backlight structure for a panel display, comprising a polarizer having at least one fluorescent layer generated as a backlight for the display.   The backlight structure according to claim 1, wherein the polarizer is a lower polarizer of a panel display.   The backlight structure according to claim 2, wherein the lower polarizer has a polarizing layer and a surface protective layer, and further, a fluorescent layer is disposed between the polarizing layer and the surface.   The backlight structure according to claim 1, wherein the polarizer further includes at least one protective layer for protecting the fluorescent layer.   The backlight structure according to claim 1, wherein the light source is a light emitting diode (LED) element.   6. The backlight structure according to claim 5, wherein the first color of the first light is red.   The polarizer has a green fluorescent layer and a blue fluorescent layer, and when the fluorescent layer is excited by the first light, the second light is generated in white or mixed light in the second color. The backlight structure according to claim 6.   6. The backlight structure according to claim 5, wherein the first color of the first light is green.   The polarizer has a red fluorescent layer and a blue fluorescent layer, and when the fluorescent layer is excited by the first light, the second light is generated in white or mixed light in the second color. The backlight structure according to claim 8, wherein   6. The backlight structure according to claim 5, wherein the first color of the first light is blue.   The polarizer further comprises a yellow fluorescent layer, and when the fluorescent layer is excited by the first light, the second light is generated in white or mixed light is generated in the second color. The backlight structure according to 10.   2. The backlight structure according to claim 1, wherein the panel display is a low temperature polysilicon (LTPS) thin film transistor liquid crystal display (TFT-LCD).   It has at least one fluorescent layer excited by the first light of the first color inside, and when the fluorescent layer is excited by the first light, the second light is used as a backlight of the panel display. A polarizer for a backlight module of a panel display, characterized in that it generates white light or mixed light in a second color.   The polarizer according to claim 13, wherein the first color of the first light is red.   Furthermore, it has a green fluorescent layer and a blue fluorescent layer, and when the fluorescent layer is excited by the first light, the second light is generated in white or mixed light is generated in the second color. The polarizer according to claim 14.   The polarizer according to claim 13, wherein the first color of the first light is green.   Furthermore, it has a red fluorescent layer and a blue fluorescent layer, and when the fluorescent layer is excited by the first light, the second light is generated in white or mixed light is generated in the second color. The polarizer according to claim 16.   The polarizer according to claim 13, wherein the first color of the first light is blue.   19. The method according to claim 18, further comprising a yellow fluorescent layer, wherein when the fluorescent layer is excited by the first light, the second light is generated in white or mixed light is generated in the second color. The polarizer of description. The polarizer according to claim 13, further comprising an adhesive layer, a plurality of protective layers, a polarizing layer, and a surface protective layer.

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