Patent ID: 12235529

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It should be understood that the structures and associated functions in the following detailed descriptions are exemplary for the purpose of further explaining the scope of the present invention. However, the present invention may be embodied in various equivalent modifications, and descriptions and illustrations are not-limiting.

It also should be understood that the term used herein in embodiments to describe direction in terms of “central”, “lateral”, “up”, “down”, “right”, “left”, “upright”, “horizontal”, “top”, “bottom”, “inside”, and “outside” are used to illustrate the present invention and for clarity. It does not hint or imply that device or part mentioned should be assembled or operated in strictly specific direction or setting. In addition, the terms “first” and “second” are also for descriptive purpose. It does not imply the strict amount. Technical features with terms “first” or “second” would illustrate or imply that one or more technical features can be included. As to detailed description of the present invention, the term “plural” and “a plurality of” indicates the amount of two or more.

Also in detailed descriptions of the present invention, it will be noted that the term “assemble”, “connected to”, “connected” should be explained and understood in the broadest way, unless the context clearly indicates otherwise. For example, the term “connected” indicates that two parts may be “fixed connected” or “detachably connected” or “integrally connected”. Similarly, the term “connected” also indicates that two parts may be “mechanically connected” or “electrically connected”, and “directly connected”, “connected by intermediate part” or “internally connected by two parts”. Alterations or modifications of the terms mentioned above will be no doubt understood and obvious to those of ordinary skill in the art.

A first preferred embodiment proposed in the present invention proposes is illustrated inFIG.1, which is a schematically cross section view of a cholesteric liquid crystal display1. The cholesteric liquid crystal display1comprising three stacked selective light reflection modules. A first selective light reflection module110for reflecting a first light, a second selective light reflection module120for reflecting a second light, and a third selective light reflection module130for reflecting a third light, are sequentially stacked from bottom to top. The wavelength ranges of the first light, the second light, and the third light are different. As a preferred embodiment, the first selective light reflection module110is but not limited to a red cholesteric liquid crystal module, the second selective light reflection module120is but not limited to a green cholesteric liquid crystal module, the third selective light reflection module130is but not limited to a blue cholesteric liquid crystal module, while the first light is red light, the second light is green light, and the third light is blue light.

The incident light goes into the cholesteric liquid crystal display1from the top of the blue cholesteric liquid crystal module130. The light goes into the blue cholesteric liquid crystal module130and partly reflected by the blue cholesteric liquid crystal module130. The remaining light which passed through the blue cholesteric liquid crystal module130goes into the green cholesteric liquid crystal module120, and then is partly reflected by the green cholesteric liquid crystal module120. The remaining light which passed through the green cholesteric liquid crystal module120goes into the red cholesteric liquid crystal module110, and then is partly reflected by the red cholesteric liquid crystal module110.

It should be understood that the cholesteric liquid crystal molecule has a feature of optical rotation. Generally, for a single layer of cholesteric liquid crystal cell, it is provided with only one direction of optical rotation, either left rotation or right rotation. When a single layer of cholesteric liquid crystal cell is activated to reflect light, there is only half of the light reflecting while the other half of the light passing through cholesteric liquid crystal cell. The resulting contrast ratio and image definition of the display is therefore affected.

For a conventional three-layer cholesteric liquid crystal display which comprising stacked red, green and blue cholesteric liquid crystal modules from bottom to top, the contrast ratio and definition of image is more seriously affected. When external light goes into the blue cholesteric liquid crystal module, only half of blue light is reflected while the other half of blue light passes through the blue cholesteric liquid crystal module and goes into the green cholesteric liquid crystal module. It affects the contrast ratio and image definition of the green cholesteric liquid crystal module. Similarly, when light goes into the green cholesteric liquid crystal module, there is only half of green light being reflected while the other half of green light passes through the green cholesteric liquid crystal module and goes into the red cholesteric liquid crystal module. It affects the contrast ratio and image definition of the red cholesteric liquid crystal module.

To overcome the aforementioned problem, the proposed cholesteric liquid crystal display1in the first preferred embodiment further comprises a first thin-film photovoltaic module140and a second thin-film photovoltaic module150. The first thin-film photovoltaic module140is disposed between the blue cholesteric liquid crystal module130and the green cholesteric liquid crystal module120. The second thin-film photovoltaic module150is disposed between the green cholesteric liquid crystal module120and the red cholesteric liquid crystal module110.

The incident light goes into the first thin-film photovoltaic module140from the lower surface of the blue cholesteric liquid crystal module130and the upper surface of the first thin-film photovoltaic module140. The first thin-film photovoltaic module140is partially photo-permeable in which the transmittance of blue light is lower than the transmittance of the other lights. The first thin-film photovoltaic module140is provided for absorbing the leaked blue light which passed through the blue cholesteric liquid crystal module130, and allowing the other light passing through it. In order to achieve the purpose, the first thin-film photovoltaic module140is preferably selected as a specific dye sensitized solar cell module which comprising first dye sensitizers being specifically responsible for harvesting blue light to conduct photovoltaic reaction.

Specific semiconducting material is necessarily comprised in dye sensitized solar cell. The first thin-film photovoltaic module140comprises a first semiconducting material. When the first thin-film photovoltaic module140is a n-type dye sensitized solar cell module, Titanium Dioxide TiO2, Niobium Pentoxide Nb2O5, Zinc Oxide ZnO, Tin Oxide SnO2, or a combination of the above may be applied as the first semiconducting material. When the first thin-film photovoltaic module140is a p-type dye sensitized solar cell module, Nickel Oxide NiO, Cuprous Oxide Cu2O, or a combination of the above may be applied as the first semiconducting material.

Regarding the second thin-film photovoltaic module150, the incident light going into the second thin-film photovoltaic module150is from the lower surface of the green cholesteric liquid crystal module120and the upper surface of the second thin-film photovoltaic module150. The second thin-film photovoltaic module150is partially photo-permeable in which the transmittance of green light is lower than the transmittance of the other lights. The second thin-film photovoltaic module150is provided for absorbing the remaining green light which passed through the green cholesteric liquid crystal module, and allowing the other light passing through it. In order to achieve the purpose, the second thin-film photovoltaic module150is preferably selected as a specific dye sensitized solar cell module which comprising second dye sensitizers being specifically responsible for harvesting green light to conduct photovoltaic reaction.

As described above, specific semiconducting material is necessarily comprised in dye sensitized solar cell. The second thin-film photovoltaic module150comprises a second semiconducting material. When the second thin-film photovoltaic module150is a n-type dye sensitized solar cell module, Titanium Dioxide TiO2, Niobium Pentoxide Nb2O5, Zinc Oxide ZnO, Tin Oxide SnO2, or a combination of the above may be applied as the second semiconducting material. When the second thin-film photovoltaic module140is a p-type dye sensitized solar cell module, Nickel Oxide NiO, Cuprous Oxide Cu2O, or a combination of the above may be applied as the second semiconducting material.

It should be noted that both p-type dye sensitized solar cell modules or both n-type dye sensitized solar cell modules may be applied for the first thin-film photovoltaic module140and the second thin-film photovoltaic module150. Surely, the second thin-film photovoltaic module150might apply different p-type/n-type dye sensitized solar cell module from the first thin-film photovoltaic module140.

Via the first thin-film photovoltaic module140, the leaked blue light which passed through the blue cholesteric liquid crystal module130is absorbed and applied for generating additional electricity. The remaining light then going into the green cholesteric liquid crystal module120for reflection is therefore much clear. Via the second thin-film photovoltaic module150, the leaked green light which passed through the green cholesteric liquid crystal module120is absorbed and applied for generating additional electricity. The remaining light then going into the red cholesteric liquid crystal module110for reflection is therefore much clear. Hence, the image quality of the cholesteric liquid crystal display1is improved.

Via the first thin-film photovoltaic module140and second thin-film photovoltaic module150, the leaked blue light and leaked green light is not only absorbed but also applied for generating additional electricity. The additional electricity might be stored for driving and/or controlling the cholesteric liquid crystal display1. The additional electricity may also be applied for powering other external devices.

Referring to the optical rotation, there is half of red light would pass through the red cholesteric liquid crystal module110. As depicted inFIG.1, an alternative embodiment is provided. The cholesteric liquid crystal display1further comprises a light absorption module160disposed below the red cholesteric liquid crystal module110for absorbing any leaked light which passed through the red cholesteric liquid crystal module110. The contrast ratio is therefore improved.

As an alternative embodiment, the light absorption module160comprises a layer of light absorption material, for example, a black sponge.

As an alternative embodiment, the light absorption module160may be a photovoltaic module to conduct photovoltaic reaction for generating electricity. Such photovoltaic module may use a crystalline silicon solar cell module because the crystalline silicon solar cell module usually looks dark. However, a thin-film photovoltaic module is also applicable.

The present invention proposes a second preferred embodiment as illustrated inFIG.2, which is a schematically cross section view of a cholesteric liquid crystal display2.

The cholesteric liquid crystal display2comprises at least two cholesteric liquid crystal modules. A second cholesteric liquid crystal module220and a first cholesteric liquid crystal module210are sequentially stacked from bottom to top. The incident light goes into the cholesteric liquid crystal display2from the top of the first cholesteric liquid crystal module210, the remaining light goes out the cholesteric liquid crystal display2from the bottom of the second cholesteric liquid crystal module220.

The first cholesteric liquid crystal module210reflects a first light while the second cholesteric liquid crystal module220reflects a second light. The wavelength ranges of the first light and the second light are different. For example, when the first cholesteric liquid crystal module210is a blue cholesteric liquid crystal module, it reflects blue light; the second cholesteric liquid crystal module220may be applied as a green cholesteric liquid crystal module for reflecting green light or a red cholesteric liquid crystal module for reflecting red light.

When the first cholesteric liquid crystal module210is a green cholesteric liquid crystal module, it reflects greed light; the second cholesteric liquid crystal module220may be applied as a red cholesteric liquid crystal module for reflecting red light. Generally, it is not applicable to apply a red cholesteric liquid crystal module as the first cholesteric liquid crystal module210. It is because the wavelength and the transmittance. A longer light wavelength results in a lower frequency and a better transmittance. A shorter light wavelength results in a higher frequency and a worse transmittance.

Comparing red/green/blue lights, red light is provided with the longest wavelength and the best transmittance, blue light is provided with the shortest wavelength and the worst transmittance, while green light is provided with the moderate wavelength and the moderate transmittance. Therefore, the blue cholesteric liquid crystal module for reflecting blue light is usually disposed at the top of a multilayer cholesteric liquid crystal display, the red cholesteric liquid crystal module for reflecting red light is usually disposed at the bottom of the multilayer cholesteric liquid crystal display, while the green cholesteric liquid crystal module for reflecting green light is usually disposed between the blue cholesteric liquid crystal module and the red cholesteric liquid crystal module.

The cholesteric liquid crystal display2further comprises a first thin-film photovoltaic module240which disposed between the first cholesteric liquid crystal module210and the second cholesteric liquid crystal module220. The incident light goes into the first thin-film photovoltaic module240from the lower surface of the first cholesteric liquid crystal module210and the upper surface of the first thin-film photovoltaic module240.

It should be noted again that the cholesteric liquid crystal molecules have a feature of optical rotation. When a single cholesteric liquid crystal cell unit is activated to reflect light, at least half of the light will leak and pass through the cholesteric liquid crystal cell without being reflected due to optical rotation. The contrast ratio and image definition of a conventional cholesteric liquid crystal display is therefore affected. The first thin-film photovoltaic module240in the cholesteric liquid crystal display2is applied for overcoming such problem.

The first thin-film photovoltaic module240is a dye sensitized solar cell module which comprising first dye sensitizers being specifically responsible for harvesting the first light, so that the first thin-film photovoltaic module240is partially photo-permeable in which the transmittance of the first light is lower than the transmittance of the other lights. When the first cholesteric liquid crystal module210is applied as a blue cholesteric liquid crystal module, the first thin-film photovoltaic module240is provided for absorbing the leaked blue light which passed through the blue cholesteric liquid crystal module, and allowing the other light passing through it then going into the second cholesteric liquid crystal module220which reflecting either green light or red light. When the first cholesteric liquid crystal module210is applied as a green cholesteric liquid crystal module, the first thin-film photovoltaic module240is provided for absorbing the leaked green light which passed through the green cholesteric liquid crystal module, allowing the other light passing through it then going into the second cholesteric liquid crystal module220which reflecting red light. The contrast ratio and image definition of the proposed cholesteric liquid crystal display2is therefore improved.

Specific semiconducting material is necessarily comprised in dye sensitized solar cell. As an embodiment, the first thin-film photovoltaic module240is a n-type dye sensitized solar cell module. A first semiconducting material comprised in the n-type dye sensitized solar cell module may be Titanium Dioxide TiO2, Niobium Pentoxide Nb2O5, Zinc Oxide ZnO, Tin Oxide SnO2, or a combination of the above. As an alternative embodiment, the first thin-film photovoltaic module240is a p-type dye sensitized solar cell module. A first semiconducting material comprised in the p-type dye sensitized solar cell module may be Nickel Oxide NiO, Cuprous Oxide Cu2O, or a combination of the above.

In order to improve the efficient of light utilization, one embodiment of the cholesteric liquid crystal display2further comprises a second thin-film photovoltaic module250which disposed below the second cholesteric liquid crystal module220. The second thin-film photovoltaic module250preferably is a dye sensitized solar cell module which comprising second dye sensitizers. The second dye sensitizers are specifically responsible for harvesting the second light which is different from the first light, so the second thin-film photovoltaic module250is partially photo-permeable in which the transmittance of the second light is lower than the transmittance of the other lights.

When the second cholesteric liquid crystal module220is applied as a green cholesteric liquid crystal module, the second thin-film photovoltaic module250is selected to be specifically responsible for harvesting green light, so the transmittance of green light is lower than the transmittance of the other lights. The leaked green light which passed through the second cholesteric liquid crystal module220would be absorbed for conducting photovoltaic reaction. The light other than green light then passes through the second thin-film photovoltaic module250.

When the second cholesteric liquid crystal module220is applied as a red cholesteric liquid crystal module, the second thin-film photovoltaic module250is selected to be specifically responsible for harvesting red light, so the transmittance of red light is lower than the transmittance of the other lights. The leaked red light which passed through the second cholesteric liquid crystal module220would be absorbed for conducting photovoltaic reaction. The light other than red light then passes through the second thin-film photovoltaic module250.

The second thin-film photovoltaic module250is preferably a dye sensitized solar cell module in which some specific semiconducting material is necessarily comprised. As an embodiment, the second thin-film photovoltaic module250is a n-type dye sensitized solar cell module. A second semiconducting material comprised in the n-type dye sensitized solar cell module may be Titanium Dioxide TiO2, Niobium Pentoxide Nb2O5, Zinc Oxide ZnO, Tin Oxide SnO2, or a combination of the above. As an alternative embodiment, the second thin-film photovoltaic module250is a p-type dye sensitized solar cell module. A second semiconducting material comprised in the p-type dye sensitized solar cell module may be Nickel Oxide NiO, Cuprous Oxide Cu2O, or a combination of the above.

When the second thin-film photovoltaic module250conducts photovoltaic reaction to generate additional electricity. The additional electricity might be stored for driving/controlling the cholesteric liquid crystal display or powering other external devices.

As depicted inFIGS.2and3, an alternative embodiment of the cholesteric liquid crystal display2further comprises a light absorption module260disposed at the bottom of the cholesteric liquid crystal display2in order to absorb the remaining light which passed through the first cholesteric liquid crystal module210and the second cholesteric liquid crystal module220.

For the embodiment in which the second thin-film photovoltaic module250is absent as depicted inFIG.3, the light absorption module260is disposed below the second cholesteric liquid crystal module220. For the embodiment in which the second thin-film photovoltaic module250is provided as depicted inFIG.2, the light absorption module260is disposed below the second thin-film photovoltaic module250.

As an embodiment, the light absorption module260comprises a layer of light absorption material, for example, a black sponge.

As an alternative embodiment, the light absorption module260may be a crystalline silicon solar cell module to conduct photovoltaic reaction and generate additional electricity. The additional electricity might be stored for driving/controlling the cholesteric liquid crystal display or powering other external devices.

The descriptions illustrated above set forth simply the preferred embodiments of the present invention; however, the characteristics of the present invention are by no means restricted thereto. All equivalent changes, alterations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the following claims.