CN100346211C - LCD Monitor - Google Patents

Abstract

The invention provides a liquid crystal display, which comprises a liquid crystal display panel and a first polarizing plate, wherein the first polarizing plate comprises a first surface and a second surface which faces the liquid crystal display panel and is opposite to the first surface, and the first surface comprises a plurality of first prism structures.

Description

LCD Monitor

technical field

The invention relates to a liquid crystal display, in particular to a semi-transmissive and semi-reflective liquid crystal display.

Background technique

Due to the advantages of thinness, low power consumption, no radiation pollution, and compatibility with semiconductor technology, liquid crystal displays are widely used in portable communication products such as notebook computers, personal digital assistants, and mobile phones.

Generally speaking, liquid crystal displays can be divided into three types according to the source of illumination light: transmissive, reflective, and transflective. Among them, transmissive liquid crystal displays usually have a backlight for generating light. And the light generated by the backlight will pass through the liquid crystal unit and various optical elements (such as polarizers), so that the user can watch the screen display of the liquid crystal display. In addition, reflective liquid crystal displays have a reflective surface (such as aluminum metal), and when the reflective liquid crystal display displays images, light (such as ambient light or front light) enters the liquid crystal display from the front of the panel and passes through the liquid crystal unit. And each optical element, and then the reflective surface reflects the light back, and the reflected light will pass through the liquid crystal unit and each optical element, and finally the user can watch the screen display of the liquid crystal display. On the other hand, a transflective liquid crystal display is a liquid crystal display with both a transmissive mode and a reflective mode, that is to say, when the ambient light intensity is strong or weaker light is required for display, the liquid crystal display can be turned off Backlight, and use ambient light as a light source to display images in reflective mode. On the contrary, when the ambient light intensity is weak or when a strong light is required for display, the LCD can turn on the backlight and use the transmissive mode to display screen, so that the power consumption of the backlight can be reduced.

In addition, since one of the development goals of portable electronic products (such as mobile phones) is to reduce power consumption, transflective liquid crystal displays are widely used in portable electronic products. For example, take a mobile phone as an example. When the mobile phone is in standby mode, the panel of the mobile phone is mostly used to display information such as time or missed calls, so usually the user can watch the display without too much light. Therefore, the panel of the mobile phone can use ambient light as a light source to display images in reflective mode. On the other hand, when the mobile phone is in use mode, the panel of the mobile phone can turn on the backlight and use the transmissive mode to display the picture in order to allow the user to clearly see the numbers or characters displayed on the panel.

For example, Taiwan Patent No. 422934 discloses a transflective liquid crystal display, which has a structure of upper polarizer/liquid crystal unit/lower polarizer/semi-transmissive reflector/background light, wherein when the background When the light is turned off, the semi-transparent reflector is used to reflect the external ambient light back, so that the liquid crystal display can display images in a reflective mode. On the contrary, when the backlight is turned on, the light generated by the backlight will pass through the semi-transparent reflective plate, so that the liquid crystal display can display images in a transmissive mode. However, since this type of liquid crystal display must add an additional half-transmission reflector to achieve the half-transmission and half-reflection effect, this will not only increase the complexity of making the liquid crystal display, but will also increase the production cost of the liquid crystal display. cost.

Contents of the invention

Therefore, one of the objectives of the present invention is to provide a transflective liquid crystal display to solve the aforementioned problems.

According to the purpose of the present invention, a preferred embodiment of the present invention provides a liquid crystal display, which includes a liquid crystal display panel and a first polarizer, the first polarizer includes a first surface, and a face facing the liquid crystal display panel and The second surface is opposite to the first surface, and the first surface contains a plurality of first prism structures.

In a preferred embodiment, the liquid crystal display of the present invention further includes a second polarizing plate disposed on the side of the liquid crystal display panel away from the first polarizing plate, the second polarizing plate includes a third protective film facing the liquid crystal display panel, A fourth protective film opposite to the third protective film, and a second polarizing film located between the third protective film and the fourth protective film. Preferably, the surface of the fourth protection film is provided with a third prism structure.

Since the lower polarizing plate of the present invention includes a plurality of prism structures, part of the ambient light can be reflected in the lower polarizing plate, so that the liquid crystal display of the present invention can use the external ambient light to display images.

Description of drawings

Fig. 1 is the schematic diagram of a liquid crystal display of the first embodiment of the present invention;

FIG. 2 is an enlarged schematic view of the lower polarizing plate shown in FIG. 1;

Fig. 3 is the optical simulation result of various prism angles of the present invention;

4 is a schematic diagram of a lower polarizer according to a second embodiment of the present invention;

5 is a schematic diagram of a lower polarizer according to a third embodiment of the present invention;

6 is a schematic diagram of a lower polarizer according to a fourth embodiment of the present invention;

7 is a schematic diagram of a lower polarizer according to a fifth embodiment of the present invention;

8 is a schematic diagram of a lower polarizer according to a sixth embodiment of the present invention;

FIG. 9 is a schematic diagram of a liquid crystal display according to the second embodiment of the present invention.

Explanation of reference signs

10 LCD display 12 LCD panel

14 Backlight module 16 Upper polarizer

18 lower polarizer 18a first side

18b second side 20a protective film

20b polarizing film 20c protective film

20d film layer 22 prism structure

22a Plane 22b Plane

22c plane 24a upper substrate

24b Lower substrate 25 Prism structure

25a Plane 25b Plane

26 Liquid crystal molecular layer 28a Conductive layer

28b Conductive layer 30 Light source

32 Light guide plate 34 Reflector

36 Diffusion film 38 Ambient light

40 light 42 user

46 ambient light 46a light

46b light rays 46c light rays

50 Liquid crystal display 52 Liquid crystal display panel

54 Backlight module 56 Upper polarizer

56a First side 56b Second side

58 lower polarizer 58a first side

58b second side 60a upper substrate

60b Lower Substrate 62 Liquid Crystal Molecular Layer

64a Conductive layer 64b Conductive layer

66 Light source 68 Light guide plate

70 Reflector 72 Diffusion film

74 Prism structure 74a plane

74b plane

Detailed ways

Please refer to FIG. 1 and FIG. 2 , FIG. 1 is a schematic diagram of a liquid crystal display according to a first embodiment of the present invention, and FIG. 2 is an enlarged schematic diagram of the lower polarizer shown in FIG. 1 . As shown in Figure 1, a liquid crystal display 10 includes a liquid crystal display panel 12, a backlight module 14, used to provide the light required by the liquid crystal display panel 12, an upper polarizer 16, arranged on the liquid crystal display panel 12, And the lower polarizer 18 is disposed between the liquid crystal display panel 12 and the backlight module 14 , and the lower polarizer 18 is used to reflect part of the ambient light passing through the liquid crystal display panel 12 . The liquid crystal display panel 12 includes an upper substrate 24a, a lower substrate 24b disposed below the upper substrate 24a, and a liquid crystal molecule layer 26 filled between the upper substrate 24a and the lower substrate 24b. On the other hand, the liquid crystal display panel 12 further includes a conductive layer 28a disposed between the upper substrate 24a and the liquid crystal molecular layer 26, and a conductive layer 28b disposed between the lower substrate 24b and the liquid crystal molecular layer 26, and the conductive layer 28 a and the conductive layer 28 b are used to provide an electric field to the liquid crystal molecule layer 26 , so that the liquid crystal molecules in the liquid crystal molecule layer 26 can generate a corresponding deflection according to the electric field, thereby producing a proper light transmittance. Generally speaking, the upper substrate 24a and the lower substrate 24b are made of transparent materials (for example: glass or quartz), and the material of the conductive layers 28a and 28b usually includes transparent conductive materials such as indium tin oxide or indium zinc oxide, and The lower polarizer 18 can select polarized light in a specific direction, that is, the lower polarizer 18 can only allow the polarized light in a specific direction to pass through.

In addition, as shown in FIG. 1, the backlight module 14 includes a light source 30 for generating light, a light guide plate 32 disposed on one side of the light source 30 and used for guiding the light generated by the light source 30, a reflector 34, It is arranged under the light guide plate 32 and used to reflect light upwards, and a diffusion film 36 is arranged above the light guide plate 32 and used for uniformizing the light. Wherein, the material of the diffusion film 36 can be polycarbonate, polyethylene terephthalate or acrylic, etc., and the reflection sheet 34 is formed by a material with a high reflection coefficient, such as aluminum, copper and other metals or their alloys. , and the light source 30 can be a cold cathode tube, a hot cathode lamp or a light emitting diode, etc. In addition, according to the requirements of different products, a protective diffusion sheet (not shown) and a prism sheet (not shown) can also be provided between the light guide plate 32 and the lower polarizer 18, and the number and sequence of the diffusion sheet and the prism sheet It can be added, deleted or adjusted according to the needs. On the other hand, the liquid crystal display panel 12 may further include a color filter (not shown in FIG. 1 ) disposed on the upper substrate 24 a for allowing the user to view a color image.

In addition, as shown in FIG. 1 , the lower polarizer 18 of the present invention includes a first surface 18 a facing the backlight module 14 and a second surface 18 b facing the liquid crystal display panel 12 , and as shown in FIG. 2 , the first surface 18a of the lower polarizer 18 includes a plurality of prism structures 22, and each prism structure 22 has a plane 22a and a plane 22b, which are used to reflect part of the ambient light (for example: the ambient light shown in FIG. 1 38). Generally speaking, the lower polarizer 18 is composed of a polarizing film 20b and two protective films 20a and 20c, wherein the material of the polarizing film 20b is usually polyvinyl alcohol (PVA), and the material of the protective films 20a and 20c is mostly acetic acid. Fiber film (TAc), and the first embodiment of the present invention uses a roller to emboss the protective film 20c to form the prism structures 22 shown in FIG. 2 on the surface of the protective film 20c.

It should be noted that, as shown in FIG. 2, since the refractive index of the lower polarizer 18 (about 1.5) is greater than the refractive index of the external environment (about 1.0), when the refracted ray 46a of the ambient light 46 is incident on the plane 22b When the incident angle of the light 46a is greater than the critical angle of the lower polarizer 18, all the light 46a will be reflected back into the lower polarizer 18, and cannot pass through the interface between the lower polarizer 18 and the external environment, in other words In other words, when the incident angle of the light 46 a is greater than the critical angle of the lower polarizer 18 , the light 46 a will be totally reflected on the plane 22 b. Similarly, when the reflected light 46b of the light 46a is incident on the plane 22a, and the incident angle of the light 46b is larger than the critical angle of the lower polarizer 18, the light 46b will be totally reflected on the plane 22a, and the light 46b The reflected light 46c will leave the lower polarizer 18 and return to the external environment. In addition, if the incident angle of the light 46b is smaller than the critical angle of the lower polarizer 18, the light 46b will pass through the plane 22a, and may be reflected in the adjacent prism structure 22, and return to the external environment. It is worth mentioning that the present invention is based on the characteristics described above, and by adjusting the angle θ ₁ between the plane 22a and the plane 22b, the ambient light at a specific angle can be reflected to the viewing angle of the liquid crystal display (viewing angle) within range. For example, if the required horizontal viewing angle and vertical viewing angle of the product are 100 degrees and 40 degrees respectively, the present invention can reflect part of the ambient light by adjusting the angle θ ₁ between the plane 22a and the plane 22b to the aforementioned range of viewing angles. In other words, the lower polarizer 18 of the present invention can not only be used to reflect part of the ambient light so that the liquid crystal display 10 can display images by the ambient light, but the present invention can also adjust the angle θ ₁ between the plane 22a and the plane 22b to make the The ambient light is reflected within the viewing angle range of the liquid crystal display 10 .

In addition, since the reflection effect of the lower polarizer 18 on ambient light is related to the angle θ ₁ between the planes 22a and 22b of the prism structures 22 (that is, the prism angle), the present invention performs optical simulations for different prism angles, The result is shown in Figure 3. Wherein, as shown in FIG. 2, during the light reflection simulation process of the lower polarizer 18, the light source injects light within 120° from the second surface 18b of the lower polarizer 18 into the lower polarizer 18, and then calculates the light The ratio of reflection is generated in the lower polarizer 18 to obtain the ratio of light reflection shown in FIG. 3 (that is, the data shown by the symbol “□”). On the other hand, during the light penetration simulation process of the lower polarizing plate 18, the light source injects the light within the range of 70° from the first surface 18a of the lower polarizing plate 18 into the lower polarizing plate 18, and then calculates the light penetration through the lower polarizing plate 18. The ratio of the polarizer 18 is used to obtain the ratio of light penetration shown in FIG. 3 (that is, the data shown by the symbol "■"). It should be noted that, as shown in FIG. 3 , when the angle _θ1 between the plane 22 a and the plane 22 b is between 70 degrees and 120 degrees, the light has a preferred reflection effect in the lower polarizer 18 .

Please continue to refer to FIG. 1 , and the display method of the liquid crystal display 10 of the present invention will be explained next. As shown in FIG. 1, when the backlight module 14 is turned on, the light 40 generated by the light source 30 first passes through the light guide plate 32, and then sequentially passes through the diffusion film 36, the lower polarizer 18, the liquid crystal display panel 12 and the upper polarizer. board 16 , and finally, the user 42 can watch the image screen of the liquid crystal display 10 . On the other hand, when the backlight module 14 is turned off, the external ambient light 38 will sequentially pass through the upper polarizer 16 and the liquid crystal display panel 12, and then part of the ambient light 38 will be reflected in the lower polarizer 18, and the reflected The ambient light 38 passes through the liquid crystal display panel 12 and the upper polarizer 16 in sequence, and finally, the user 42 can see the image screen of the liquid crystal display 10 . In addition, the aforementioned traveling paths of the ambient light 38 and the light 40 are only used to explain the display mode of the liquid crystal display 10 of the present invention, not the actual traveling paths of the light.

It is worth mentioning that, since the lower polarizing plate 18 of the present invention has a plurality of prism structures 22, the proportion of ambient light reflected in the lower polarizing plate 18 can be increased, so that the liquid crystal display 10 can use ambient light to display images, in other words , the present invention does not need to add an additional half-transmissive and semi-reflective film to achieve the effect of semi-transmissive and semi-reflective, so the present invention can not only reduce the complexity of manufacturing liquid crystal displays, but also reduce the production cost of liquid crystal displays. In addition, as shown in Figure 1, since the ambient light 38 is reflected in the lower polarizing plate 18, the ambient light 38 passes through the upper polarizing plate 16, the lower polarizing plate 18 and the upper polarizing plate 16 in sequence, and because the ambient light 38 passes through the two polarizing plates polarizing plate, so the contrast of the liquid crystal display 10 is relatively good, so the present invention can improve the contrast effect of the liquid crystal display 10 .

On the other hand, the lower polarizer 18 shown in FIG. 2 is not the only structure of the present invention, and the structure of the lower polarizer of other embodiments of the present invention will be introduced below. Please refer to FIG. 4 . FIG. 4 is a schematic diagram of a lower polarizing plate according to a second embodiment of the present invention, wherein a plane 22 c may be included between two adjacent prism structures 22 . In addition, please refer to FIG. 5. FIG. 5 is a schematic diagram of a lower polarizing plate according to a third embodiment of the present invention, wherein the third embodiment of the present invention uses methods such as screen printing or sticking to form each prism structure 22 on the protective film 20c, and each prism structure 22 is usually made of hardened resin. In addition, please refer to FIG. 6. FIG. 6 is a schematic diagram of a lower polarizing plate according to a fourth embodiment of the present invention, wherein the lower polarizing plate 18 further includes a film layer 20d, and each prism structure 22 is formed on the surface layer of the film layer 20d. In addition, The film layer 20d is attached to the surface of the protective film 20c through a diffusion glue 21, and the diffusion glue 21 is used to atomize light and is made of PSA pressure-sensitive adhesive, and the material of the film layer 20d includes hardened resin. Please refer to FIG. 7. FIG. 7 is a schematic diagram of the lower polarizer of the fifth embodiment of the present invention, wherein the lower polarizer 18 further includes a thin film layer 20d, and the fifth embodiment of the present invention utilizes methods such as screen printing or pasting, Each prism structure 22 is formed on the surface of the film layer 20d. In addition, the film layer 20d is attached to the surface of the protective film 20c via a diffusion glue 21, and the diffusion glue 21 is used to atomize light and is pressure-sensitively adhered by PSA. agent, and the material of the film layer 20d and each prism structure 22 includes cured resin. Please refer to FIG. 8. FIG. 8 is a schematic diagram of a lower polarizing plate according to a sixth embodiment of the present invention, wherein the second surface 18b of the lower polarizing plate 18 also includes a plurality of prism structures 25, and each prism structure 25 is formed on the protective film 20a. surface layer, and each prism structure 25 has a plane 25a and a plane 25b, and in the fifth embodiment of the present invention, the included angle θ ₂ between the plane 25a and the plane 25b is between 70° and 120°, and each The manufacturing method of the prism structure 25 can be any one shown in FIG. 4 to FIG. 7 .

In addition, please refer to FIG. 9 , which is a schematic diagram of a liquid crystal display according to a second embodiment of the present invention. As shown in FIG. 8 , a liquid crystal display 50 includes a liquid crystal display panel 52 and a backlight module 54 for generating light. Wherein, the liquid crystal display panel 52 includes an upper substrate 60a, a lower substrate 60b disposed below the upper substrate 60a, a liquid crystal molecular layer 62 filled between the upper substrate 60a and the lower substrate 60b, and a conductive layer 64a disposed on the upper substrate 60a. Between the substrate 60 a and the liquid crystal molecule layer 62 , and a conductive layer 64 b is disposed between the lower substrate 60 b and the liquid crystal molecule layer 62 . In addition, the backlight module 54 includes a light source 66 , a light guide plate 68 , a reflection sheet 70 and a diffusion film 72 .

As shown in Figure 9, the liquid crystal display 50 further includes an upper polarizer 56, which is arranged on the liquid crystal display panel 52 and allows polarized light in a certain direction to pass through, and a lower polarizer 58, which is arranged on the liquid crystal display panel 52 and the backlight. Between the modules 54, polarized light in a certain direction is allowed to pass through. Wherein, the lower polarizer 58 includes a first surface 58a having a plurality of prism structures 59, and a second surface 58b opposite to the first surface 58a, and the function of the lower polarizer 58 is the same as that of the lower polarizer shown in FIG. 18 , that is, part of the ambient light passing through the liquid crystal display panel 52 will be reflected in the lower polarizer 58 . On the other hand, the structure of the lower polarizer 58 is not limited to that shown in FIG. 9 , and the structure of the lower polarizer 58 may also be one of those shown in FIGS. 4 to 8 .

In addition, as shown in FIG. 9, the upper polarizer 56 includes a first surface 56a and a second surface 56b, wherein the second surface 56b includes a plurality of prism structures 74, and each prism structure 74 has a plane 74a and a plane 74b, and the included angle between the plane 74a and the plane 74b is between 70° and 120°. It should be noted that the upper polarizer 56 is used to increase the amount of incident light, thereby increasing the reflection ratio of ambient light in the lower polarizer 58 .

It should be noted that the aforementioned prism structures 22 , 25 , 59 and 74 are all symmetrical structures, but the present invention is not limited thereto, and each of the aforementioned prism structures may also be an asymmetrical structure. In addition, the above-mentioned backlight modules 14 and 54 are all side-lit backlight modules, but the present invention is not limited thereto, and direct-lit backlight modules are also applicable to the liquid crystal display of the present invention.

Compared with the prior art, the liquid crystal display 10 (or 50) of the present invention includes a lower polarizer 18 (or 58), and the lower polarizer 10 (or 50) includes a plurality of facing backlight modules 14 (or 54 ) prism structure 22 (or 59), so part of the ambient light will be reflected in the lower polarizer 18 (or 58), so that the liquid crystal display 10 (or 50) can use the external ambient light to display images. In other words, the liquid crystal display of the present invention can achieve the effect of semi-transmissive and semi-reflective without adding an additional half-transmissive reflector. Therefore, the present invention can reduce the complexity of manufacturing the liquid crystal display, thereby reducing the manufacturing cost of the liquid crystal display. In addition, because the number of times the ambient light passes through the polarizing plate increases, the invention can improve the contrast effect of the liquid crystal display.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the patent of the present invention.

Claims (10)

1. LCD, it includes:

One display panels;

One light source is in order to produce light; And

One first Polarizer is arranged between this display panels and this light source and includes one towards first of this light source, and wherein this first bread contains a plurality of first prism structures.

2. LCD as claimed in claim 1, wherein respectively this first prism structure all includes a symmetry structure or an asymmetry structure.

3. LCD as claimed in claim 2, wherein respectively this first prism structure all includes one first plane and one second plane, and the angle on this first plane and this second plane is between 70 degree and 120 degree.

4. LCD as claimed in claim 3, wherein this first Polarizer includes one in addition towards second of this display panels, this second bread contains a plurality of second prism structures, and respectively this second prism structure all includes one the 3rd plane and Siping City's face, and the 3rd plane and this quadriplanar angle are between 70 degree and 120 degree.

5. LCD as claimed in claim 4, wherein this LCD includes one second Polarizer in addition, and this display panels is between this first Polarizer and this second Polarizer, wherein this first Polarizer is used for selecting the polarized light of a first direction, and this second Polarizer is used for selecting the polarized light of a second direction.

6. LCD as claimed in claim 5, wherein this second Polarizer includes the 3rd and one fourth face with respect to the 3rd in the face of this display panels, and this fourth face includes a plurality of prism structures.

7. LCD as claimed in claim 6, wherein respectively this prism structures all includes one the 5th plane and one the 6th plane, and the angle on the 5th plane and the 6th plane is between 70 degree and 120 degree.

8. LCD as claimed in claim 7; wherein this first Polarizer includes first diaphragm towards this light source; one second diaphragm, and first light polarizing film between this first diaphragm and this second diaphragm towards this display panels.

9. LCD as claimed in claim 8; wherein this second Polarizer includes the 3rd diaphragm towards this display panels; one the 4th diaphragm, and second light polarizing film between the 3rd diaphragm and the 4th diaphragm with respect to the 3rd diaphragm.

10. LCD as claimed in claim 9, wherein those first prism structures are arranged on this first diaphragm, and those second prism structures are arranged on this second diaphragm, and those prism structures are arranged on the 4th diaphragm.

Images