# US 8,570,467 B2 · Liquid crystal display and the fabricating method of the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,467 B2 - Document ID: US8570467B2 - Status: Granted - Kind: B2 - Application number: 13/049,754 - Filed: 2011-03-16 - Published: 2012-06-14 - Granted: 2013-10-29 - Earliest claimed: 2010-12-09 - Assignees: Samsung Display Co., Ltd. - Applicants: Gee-Bum Kim; Won-Sang Park; Jae-Hyun Kim; Jae-Ik Lim; Jong-In Baek; Yong-Seok Yeo - Inventors: Gee-Bum Kim; Won-Sang Park; Jae-Hyun Kim; Jae-Ik Lim; Jong-In Baek; Yong-Seok Yeo - Web page: https://patentgrep.com/patent/US8570467B2 ## CPC - G02F 1/133555: {Transflectors} - G02F 1/133541: {Circular polarisers} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract A transflective liquid crystal display (LCD) includes: a first substrate formed with a thin film transistor and a pixel electrode connected to the thin film transistor; a second substrate formed with a common electrode and a color filter and facing the first substrate; a liquid crystal layer formed between the first substrate and the second substrate; a first polarizing plate disposed at one side of the first substrate that does not face the second substrate; a second polarizing plate disposed at one side of the second substrate that does not face the first substrate; a cholesteric film formed on the first substrate; and a backlight unit disposed at one side of the first polarizing plate that does not face the first substrate. ## Claims ### Claim 1 A liquid crystal display (LCD) comprising: a first substrate arranged with a thin film transistor and a pixel electrode connected to the thin film transistor; a second substrate arranged with a common electrode and a color filter and facing the first substrate; a liquid crystal layer between the first substrate and the second substrate; a first polarizing plate located at one side of the first substrate facing away from the second substrate; a second polarizing plate located at one side of the second substrate facing away from the first substrate; a cholesteric film on the first substrate, the cholesteric film comprising reflective layers adapted to reflect or transmit incident light as a function of a polarization direction and transmissive layers having a refractive index isotropy, the reflective lavers and the transmissive layers being positioned adjacent one another according to an alternating pattern on the thin film transistor; and a backlight unit located at one side of the first polarizing plate facing away from the first substrate. ### Claim 2 (depends on 1) The liquid crystal display (LCD) of claim 1, wherein the reflective layer and the transmissive layer are located at an entire area of one pixel. ### Claim 3 (depends on 1) The liquid crystal display (LCD) of claim 1, wherein a reflectance of the reflective layer of the cholesteric film is 100%. ### Claim 4 (depends on 1) The liquid crystal display (LCD) of claim 1, wherein a reflectance of the cholesteric film is 50%. ### Claim 5 (depends on 1) The liquid crystal display (LCD) of claim 1, wherein the first polarizing plate and the second polarizing plate respectively change incident light into different circular polarization directions. ### Claim 6 (depends on 1) The liquid crystal display (LCD) of claim 1, wherein: the cholesteric film is disposed between the thin film transistor and the pixel electrode; and the cholesteric film has a hole to connect the thin film transistor and the pixel electrode. ### Claim 7 (depends on 1) The liquid crystal display (LCD) of claim 1, further comprising a protective layer on the thin film transistor. ### Claim 8 (depends on 7) The liquid crystal display (LCD) of claim 7, further comprising an organic layer on the protective layer. ### Claim 9 (depends on 1) The liquid crystal display (LCD) of claim 1, further comprising a diffusion layer between the second substrate and the second polarizing plate. ### Claim 10 (depends on 1) The liquid crystal display (LCD) of claim 1, wherein the color filter comprises light diffusion particles. ### Claim 11 (depends on 1) The liquid crystal display (LCD) of claim 1, wherein: the liquid crystal layer is an electrically controlled birefringence (ECB) mode liquid crystal layer, a vertical alignment (VA) mode liquid crystal layer, an optically compensated birefringence (OCB) mode liquid crystal layer, or a hybrid aligned nemaic (HAN) mode liquid crystal layer. ### Claim 12 A liquid crystal display (LCD) comprising: a first substrate arranged with a thin film transistor and a pixel electrode connected to the thin film transistor; a second substrate arranged with a common electrode and a color filter and facing the first substrate; a liquid crystal layer between the first substrate and the second substrate; a first polarizing plate located at one side of the first substrate facing away from the second substrate; a second polarizing plate located at one side of the second substrate facing away from the first substrate; a cholesteric film on the first substrate; a backlight unit located at one side of the first polarizing plate facing away from the first substrate; and a ¼ wavelength plate and a cholesteric reflective plate disposed between the first polarizing plate and the backlight unit. ### Claim 13 (depends on 12) The liquid crystal display (LCD) of claim 12, wherein the reflectance of the cholesteric reflective plate is 100%. ### Claim 14 A method for manufacturing a liquid crystal display (LCD), the method comprising: forming a thin film transistor on a first substrate; forming a cholesteric film on the thin film transistor, the cholesteric film comprising reflective layers for reflecting or transmitting incident light as a function of a polarization direction and transmissive layers having a refractive index isotropy, the reflective layers and the transmissive layers positioned adjacent one another according to an alternating pattern on the thin film transistor; forming a hole in the cholesteric film; forming a pixel electrode connected to the thin film transistor through the hole; forming a color filter and a common electrode on a second substrate, injecting a liquid crystal contacting the first substrate and the second substrate and between the first substrate and the second substrate; disposing a first polarizing plate at one side of the first substrate facing away from the second substrate; disposing a second polarizing plate at one side of the second substrate facing away from the first substrate; and disposing a backlight unit at one side of the first polarizing plate facing away from the first substrate. ### Claim 15 (depends on 14) The method of claim 14, wherein the cholesteric film is formed by irradiating ultraviolet (UV) light to a reactive mesogen and by heat-treating it. ### Claim 16 (depends on 15) The method of claim 15, wherein the ultraviolet (UV) light is selectively irradiated to the reactive mesogen to form the reflective layer and the transmissive layer. ### Claim 17 (depends on 16) The method of claim 16, wherein the reflective layer and the transmissive layer are formed at an entire area of one pixel. ### Claim 18 (depends on 16) The method of claim 16, wherein the reflective layer and the transmissive layer are formed as part of a same layer in one pixel. ### Claim 19 (depends on 16) The method of claim 16, wherein the reflectance of the reflective layer is 100%. ### Claim 20 (depends on 14) The method of claim 14, wherein the reflectance of the cholesteric film is 50%. ### Claim 21 (depends on 14) The method of claim 14, Wherein a protective layer is formed on the thin film transistor. ### Claim 22 (depends on 14) The method of claim 14, wherein a diffusion layer is formed between the second substrate and the second polarizing plate. ### Claim 23 (depends on 14) The method of claim 14, wherein light diffusion particles are formed in the color filter. ### Claim 24 A method for manufacturing a liquid crystal display (LCD), the method comprising: forming a thin film transistor on a first substrate; forming a cholesteric film on the thin film transistor; forming a hole in the cholesteric film; forming a pixel electrode connected to the thin film transistor through the hole; forming a color filter and a common electrode on a second substrate, injecting a liquid crystal contacting the first substrate and the second substrate and between the first substrate and the second substrate; disposing a first polarizing plate at one side of the first substrate facing away from the second substrate; disposing a second polarizing plate at one side of the second substrate facing away from the first substrate; and disposing a backlight unit at one side of the first polarizing plate facing away from the first substrate, wherein a ¼ wavelength plate and a cholesteric reflective plate are arranged between the first polarizing plate and the backlight unit. ### Claim 25 (depends on 24) The method of claim 24, wherein an organic layer is formed on a protective layer.