Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
  • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
  • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
  • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
  • G09G3/3611—Control of matrices with row and column drivers
  • G09G3/3685—Details of drivers for data electrodes
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
  • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
  • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
  • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
• • G—PHYSICS
  • G02—OPTICS
  • 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
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
• • G—PHYSICS
  • G02—OPTICS
  • 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
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
  • G02F1/133553—Reflecting elements
  • G02F1/133555—Transflectors
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G2300/00—Aspects of the constitution of display devices
  • G09G2300/04—Structural and physical details of display devices
  • G09G2300/0439—Pixel structures
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G2300/00—Aspects of the constitution of display devices
  • G09G2300/04—Structural and physical details of display devices
  • G09G2300/0439—Pixel structures
  • G09G2300/0456—Pixel structures with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
  • G09G2330/02—Details of power systems and of start or stop of display operation
  • G09G2330/021—Power management, e.g. power saving

Definitions

• the present disclosure relates, in general, to a display. More specifically, the disclosure relates to Liquid Crystal Displays (LCDs).
• LCDs Liquid Crystal Displays
• both reflected ambient light and transmitted back light may contribute to the color as represented in a pixel.
• the color produced by the reflected portion of the pixel may produce a desaturated color, while the transmitted portion of the pixel may provide a color of fidelity.
• the overall color from both the reflected portion and the transmitted portion may still be a color of good fidelity with enhanced brightness, resolution and readability.
• the desaturated color from the reflected portion may be so strong as to affect the overall fidelity of the color produced by both the reflected portion and the transmitted portion.
• the quality and readability of color images and color videos in bright light conditions may suffer.
• FIG. 1 is a schematic of a cross section of a pixel of a LCD
• FIG. 2 illustrates a part of an example circuit driving a pixel via four capacitors
• FIG. 3 illustrates a part of an example circuit driving a pixel via two transistors
• FIG. 4 illustrates an example latched pixel driving circuit
• FIG. 5 illustrates an LCD in an example operating mode with the reflective portions of the pixels turned "off
• FIG. 6 illustrates an LCD in an example operating mode with the reflective portions driven identically to the transmissive portions of each pixel
• FIG. 7 is an example block diagram for an LCD with capability to operate in a low field rate mode. 60203-0018
• a triple mode LCD provides any color saturation in ambient illumination, a monochrome reflective mode, and a full color saturation transmissive mode.
• a multi-mode display system comprises a multi-mode liquid crystal display comprising a plurality of pixels. A pixel in the plurality of pixels comprises a transmissive part and a reflective part.
• the multi-mode display system comprises a latched pixel driving circuit.
• the latched pixel driving circuit comprises a transmissive latching section comprising a transmissive data input coupled to the transmissive part of each pixel, which is configured to drive a transmissive data value from the transmissive data input and to set the transmissive part of the pixel to a transmissive display state based on the transmissive data value.
• the latched pixel driving circuit comprises a reflective latching section comprising a reflective data input coupled to the reflective part of each pixel, and is configured to drive a reflective data value from the reflective data input and to set the reflective part of the pixel to a reflective display state based on the reflective data value.
• the transmissive data value is provided from a plurality of transmissive data values.
• the transmissive display state is from a plurality of transmissive display states.
• the reflective data value is from a plurality of reflective data values.
• the reflective display state is from a plurality of reflective display states.
• the transmissive data input to a transmissive part of a pixel is independent of the reflective data input to a reflective part of the pixel. Each such data input may or may not be set to different values.
• a reflective part in a pixel may be configured to a black or non-black reflective display state.
• a transmissive part in a pixel may be configured to a black or non-black transmissive display state.
• the techniques applied to a pixel as described herein may be applied to or used with a sub-pixel.
• the term "pixel" may correspond to a sub-pixel.
• two or more pixels as described herein may form a single composite pixel as a basic picture element.
• three pixels as described herein may be used as three sub-pixels, each of which is assigned to produce a different color.
• the three sub-pixels may be considered as a single composite pixel and a single picture element.
• the multi-mode display may operate in a transflective mode in which identical data input values are provided to both reflective and transmissive parts of a pixel.
• the reflective part of each pixel (or sub-pixel if so used) can be driven to an identical electrical field state (with an identical reflective data input value) such that the reflective part of each pixel appears black, while the transmissive part of each pixel can be driven by image data.
• an identical electrical field state with an identical reflective data input value
• the transmissive part of each pixel can be driven by image data.
• the multi-mode LCD as described herein forms a part of a computing device or other electronic apparatus, including but not limited to a laptop computer, notebook computer, ebook, cell phone, and netbook computer.
• Various embodiments relate to a Liquid Crystal Display (LCD) that is capable of functioning in multi-mode, a monochrome reflective mode and a color transmissive mode.
• LCD Liquid Crystal Display
• FIG. 1 is a schematic of a cross section of a pixel 100 of a LCD.
• Pixel 100 comprises a liquid crystal material 104, a pixel electrode (or a first electrode layer) 106 that includes switching elements, a common electrode (or a second electrode layer) 108, a first reflective layer 160 that is located on one side of electrode 106, a second reflective layer 150 that is located on the other side of the electrode 106, a transmissive part 112, first and second substrate layers 114 and 116, spacers 118a and 118b, a first polarization layer 120, and a second polarization layer 122.
• first and second reflective layers 160 and 150 have an opening over the transmissive part 112.
• a surface of first reflective layer 160 forms in part a reflective part 110.
• a surface of second reflective layer 150 may be used to reflect light incident from the left-hand side of the surface.
• a light source 102 or an ambient light 124 illuminates pixel 100. Examples of light source 102 include, but are not limited to, Light Emitting Diodes backlights (LEDs), Cold-Cathode Fluorescent Lamps backlights (CCFLs), and the like.
• Ambient light 124 can be sunlight or any external source of light.
• liquid crystal material 104 which is an optically active material, rotates the axis of the polarization of the light from light source 102 or ambient light 124.
• Liquid crystal 104 can be a Twisted Nematic (TN), an Electrically Controlled Birefringence (ECB) and the like.
• TN Twisted Nematic
• EBC Electrically Controlled Birefringence
• the rotation of the polarization orientation of the light is determined by the potential difference applied between pixel electrode 106, and common electrode 108.
• pixel electrode 106 and common electrode 108 can be made of Indium Tin Oxide (ITO). Further, each pixel is provided with a pixel electrode 106, while common electrode 108 is common to all the pixels present in the LCD.
• ITO Indium Tin Oxide
• reflective part 110 is electrically conductive and reflects ambient light 124 to illuminate pixel 100.
• the first reflective layer 160 is made of metal and is electrically coupled to pixel electrode 106 thereby providing the potential difference between reflective part 110 and common electrode 108.
• Transmissive part 112 transmits light from light source 102 to illuminate pixel 100.
• Substrates 114 and 116 enclose liquid crystal material 104, pixel electrode 106 and common electrode 108.
• pixel electrode 106 is located at substrate 114
• common electrode 108 is located at substrate 116.
• substrate 114 and pixel electrode layer comprises switching elements (not shown in FIG. 1). In an embodiment, the switching elements can be Thin Film Transistors (TFTs).
• a driver circuit 130 which may be a part of or in addition to a latched pixel driving circuit 400, sends signals related to pixel values to the switching elements.
• driver circuit 130 uses low voltage differential signaling (LVDS) drivers.
• LVDS low voltage differential signaling
• TTL transistor-transistor logic
• a timing controller 140 encodes signals (e.g., transmissive data input values as previously described) related to pixel values into the signals needed by the transmissive parts of the pixels, and signals (e.g., reflective data input values as previously described) related to pixel values into the signals needed by the reflective parts of the pixels.
• timing controller 140 has a memory to allow self-refresh of the LCD when the signals related to the pixels are removed from timing controller 140.
• spacers 118a and 118b are placed over reflective part 110 to maintain a uniform distance between substrates 114 and 116.
• pixel 100 comprises first polarizer 120 and second polarizer 122.
• the axes of polarity of first polarizer 120 and second polarizer 122 are perpendicular to each other.
• the axes of polarity of first polarizer 120 and second polarizer 122 are parallel to each other.
• Pixel 100 is illuminated by light source 102 or ambient light 124.
• the intensity of light passing through pixel 100 is determined by the potential difference between pixel electrode 106, and common electrode 108.
• liquid crystal material 104 is in a disoriented state and the light passing through first polarizer 120 is blocked by second polarizer 122 when no potential difference is applied between pixel electrode 106, and common electrode 60203-0018
• Liquid crystal material 104 is oriented when the potential difference is applied between pixel electrode 106, and common electrode 108. The orientation of liquid crystal material 104 allows the light to pass through second polarizer 122.
• first reflective layer 160 is placed on one side of electrode 106, while second reflective layer 150 may be placed on the opposite side of electrode 106.
• the second reflective layer 150 may be made of metal, reflecting or bouncing light 126 (incident from the left-hand side of FIG. 1) one or more times until the light 126 transmits through the transmissive part 112 to illuminate pixel 100.
• straight lines indicate light path segments of lights 112, 124, 126.
• Each of the light path segments may comprise additional bending due to diffractions which may occur when lights 112, 124, 126 travel through junctions between media of different refractive indexes.
• the pixel 100 is illustrated with two spacers 118a and 118b.
• two neighboring spacers may be placed one or more pixels apart, every ten pixels apart, every twenty pixels apart, every 100 pixels apart, or other distances apart.
• FIG. 2 illustrates a part of an example circuit driving a pixel via four capacitors.
• Pixel 100 comprises transmissive part 112 and reflective part 110.
• the display state of transmissive part 112 can be controlled in part by a circuit portion 210 comprising first and second capacitors 214 and 218.
• the first capacitor 214 is formed by two electrodes (or conductors) separated by a portion of the liquid crystal material in the transmissive part 112 and derives its capacitance from that portion of the liquid crystal material.
• the second capacitor 218 is a storage capacitor that helps maintain the first capacitor in a stable charged state and may be formed in part by a portion of a thin film layer inserted into the pixel structure.
• the first capacitor 214 when the multi-mode LCD is operating in a monochromatic reflective mode, the first capacitor 214 may be placed in a charged state that makes the transmissive part 112 look dark black or appear at another specific brightness level. In such a charged state, a voltage of 0, 2.5, 5, or a different value, may be maintained over the portion of the liquid crystal material in the transmissive part 112 through the first and second capactors 214 and 218.
• the first and second capacitors 214 and 218 are connected in parallel and may be connected to the same electric source or drain at points 222 and 228 in charging or discharging cycles.
• a display state of reflective part 110 can be controlled in part by a circuit portion 212 comprising third and fourth capacitors 216 and 220.
• the 60203-0018 third capacitor 216 is formed by two electrodes (or conductors) separated by a portion of the liquid crystal material in the reflective part 110 and derives its capacitance from that portion of the liquid crystal material.
• the fourth capacitor 220 is a storage capacitor that helps maintain the third capacitor in a stable charged state and may be formed in part by another portion of the thin film layer inserted into the pixel structure.
• the third capacitor 216 when the multi-mode LCD is operating in a monochromatic reflective mode, the third capacitor 216 may be placed in a charged state that makes the reflective part 110 look dark black or appear at another specific brightness level. In such a charged state, a voltage of 0, 2.5, 5, or a different value, may be maintained over the portion of the liquid crystal material in the reflective part 110 by the third and fourth capactors 216 and 220.
• the third and fourth capacitors 216 and 220 are connected in parallel and may be connected to the same electric source or drain at points 224 and 226 in charging or discharging cycles.
• the latched pixel driving circuit 400 may use these separate capacitors to set the reflective part 110 and the transmissive part 112 to independent display states.
• the reflective part 110 may be dark black by holding a particular voltage across the third capacitor 216, while the transmissive part 112 may be driven by image data to a specific color by holding a different voltage across the first capacitor that enables the reading of a pixel value from the image data.
• the transmissive part 112 may be dark black while the reflective part 110 may be driven by image data to a specific shade of gray.
• the reflective part 110 and the transmissive part 112 may both be driven by the same image data by holding the capacitors to the same or different voltages in various embodiments.
• FIG. 3 illustrates a part of an example circuit driving a pixel using two transistors.
• the circuit portion 210 may further comprise a transistor 310 in addition to the first and second capacitors 214 and 218.
• One terminal of the capacitors 214 and 218 is connected to an electric source or drain through a junction 314 of the transistor 310.
• the charging or discharging of the first and second capacitors 214 and 218 is controlled by applying different gate voltages to the transistor 310. For example, when the capacitors 214 and 218 should be charged or discharged, a gate voltage may be applied to the gate junction of the transistor 310 to enable the capacitors connected through the junction 314 to the electric source or drain over near zero, or very low, resistance.
• the circuit portion 226 may further comprise a transistor 312 in addition to the third and fourth capacitors 216 and 220. One terminal of the capacitors 216 and 220 is connected to an electric source or drain through a junction 316 of the transistor 312.
• the charging or discharging of the third and fourth capacitors 216 and 220 can be controlled by applying different gate voltages to the transistor 312. For example, when the capacitors 216 and 220 should be charged or discharged, a gate voltage may be applied to the gate junction of the transistor 312 to enable the capacitors connected through the junction 316 to the electric source or drain over near zero, or very low, resistance. When the capacitors 216 and 220 should maintain their current charged state at a particular voltage level, a different gate voltage may be applied to the gate junction of the transistor 312 to cause the capacitors 216 and 220 to be effectively disconnected from the junction 316 or only connected over very high resistance in order to prevent or to slow charging or discharging of the capacitors 214 and 218.
• the latched pixel driving circuit 400 may use these separate capacitors and transistors to set the reflective part 110 and the transmissive part 112 to independent display states in a manner similar to that previously described.
• FIG. 4 illustrates an example latched pixel driving circuit 400.
• pixel values communicated using signal 402 that are generated based on image data can be provided to pixels through first circuit columns 404 and second circuit columns 406.
• Signals from first columns 404 drive transmissive switching elements 408 of the transmissive parts 112 of pixels such as pixel 100, while signals from second columns 406 are used to drive reflective switching elements 410 of the reflective parts 110 of pixels 100.
• the same signal 402 may be present on both columns 404 and 406 for the pixel 100.
• the switching elements 408 and 410 of the transmissive part 112 and the reflective part 110, respectively may be driven by the same pixel value as carried by the signal 402.
• the latched pixel driving circuit 400 is used to drive the reflective switching elements 410 separately from the transmissive switching elements 408.
• the latched pixel driving circuit 400 may comprise a transmissive latching circuit section 430 and a reflective latching circuit section 432 logically (not necessarily physically as the two circuit sections may share common circuit elements).
• the transmissive latching circuit section comprises first rows 420, first columns 404, and circuit elements related to these rows and columns.
• the reflective latching circuit section comprises second rows 422, second columns 406, and circuit elements related to those rows and columns.
• the first rows 420 may be configured to control the states of the transistors 310, the 60203-0018 first capacitors 214, and the second capacitors 218 in the transmissive parts 112 of the pixels 100.
• the first rows 420 may be configured to set the first capacitors 214 and the second capacitors 218 to a particular voltage and cause the transmissive switching elements 408 to ignore signals on the first columns 404. Based on this particular voltage, all the transmissive parts 112 may be set to a same display state.
• the second rows 422 may be configured to control the states of the transistors 312, the third capacitors 216, and the fourth capacitors 220 in the reflective parts 110 of the pixels 100.
• the second rows 422 may be configured to set the third capacitors 216 and the fourth capacitors 220 to a particular voltage and cause the reflective switching elements 410 to ignore signals on the second columns 406. Based on this particular voltage, all the reflective parts 110 may be set to a same display state.
• the latched pixel driving circuit 400 of FIG. 4 separately controls the reflective parts and the transmissive parts of pixels.
• Different latched pixel driving circuits and different configurations may be used. For example, instead of causing a switching element of a pixel to ignore a driving signal representing a pixel value (or a part thereof), a driving signal such as 402 may be a switched signal that can be switched off.
• a driving signal such as 402 may be a switched signal that can be switched off.
• different numbers or different types of electric elements may be used to place the transmissive part and the reflective part in separate display states.
• these and other ways of separately controlling the reflective parts and the transmissive parts of pixels may be used.
• the switching element of the reflective part 110 of each pixel 100 may receive a dedicated reflective data input in the form of data values inputted from a corresponding row and column combination, while the separate switching element of the transmissive part 112 of each pixel 100 may receive a separate dedicated transmissive data input in the form of separate data values inputted from a separate corresponding row and column combination.
• the reflective data inputs from the latched pixel driving circuit 400 can drive the reflective switching elements with different reflective data values, causing the reflective switching elements to enter different reflective display states. In an embodiment, different reflective states relate to color value, shades of gray, or brightness.
• the same switching elements can also be driven by the same global reflective data value during a time interval, thereby causing the reflective parts to the same reflective display state substantially simultaneously based on the same global reflective data value.
• substantially simultaneously typically means less than 0.1 second.
• the transflective data inputs from the latched pixel driving circuit 400 can drive the 60203-0018 transflective switching elements with different transflective data values, thereby placing these transflective switching elements in different transflective display states relating to color value, shades of gray, or brightness.
• These same switching elements can also be driven by the same global transflective data value during a time interval, thereby causing the transflective parts to the same transflective display state substantially simultaneously based on the same global transflective data value.
• FIG. 5 illustrates an LCD 510 in an example operating mode with the reflective portions of the pixels turned off.
• An ambient light source 512 such as the sun may provide a bright light condition. If the LCD operates in a transflective mode, strong ambient light may cause severe color desaturation in the reflective parts 212 of the LCD 510. While the transmissive parts 210 of the LCD 510 may provide colors of appropriate color desaturation, the LCD 510 overall may present color images with poor fidelity, as affected by the severe color desaturation in the reflective parts 212 of the LCD 510.
• the multi-mode LCD 510 as described herein is able to control the reflective parts 212 separately from the transmissive parts 210. For example, the reflective parts 212 can be placed in an appropriate display state such as dark black, while the transmissive parts 210 can be used to generate images based on image data with high fidelity.
• FIG. 6 illustrates an LCD 610 in an example operating mode with the reflective portions driven identically to the transmissive portions of each pixel, in various embodiments.
• the ambient light may be not so bright as to render color images severely desaturated.
• ambient light from a source 512 such as the sun may provide additional light to illuminate the liquid crystal material in the LCD 610 through reflectance.
• the luminance from both a back light source and the ambient light may provide better quality images than without the ambient light.
• the multi-mode LCD 610 as described herein is able to control the reflective parts 212 separately from the transmissive parts 210.
• the reflective parts 212 can be made to receive the same image data as that received by the transmissive parts 210.
• Both the reflective parts 212 and the transmissive parts 210 can be used to generate images based on the same image data with high fidelity.
• a pixel 100 in a multi-mode LCD as described herein can be used in the color transmissive mode in the same manner as a sub-pixel in a standard color pixel.
• three pixels 100 can form a single composite pixel and be electronically driven by a multi-bit signal representing a RGB value (for example, a 24-bit signal) to produce the specified red, green, and blue component colors in the composite pixel.
• a pixel 100 as described herein can be used as a black-and- 60203-0018 white pixel in a black-and-white reflective mode.
• three pixels 100 in a composite pixel of the multi-mode LCD can be individually, or alternatively collectively, electronically driven by a single 1-bit signal to produce either black or white in the pixels.
• each of the pixels 100 in a composite pixel of the multi-mode LCD can be individually electronically driven by a different 1-bit signal to produce either black or white in each pixel 100.
• power consumption is drastically reduced by (1) using 1- bit signals as compared with the multi-bit signals in the color transmissive mode and/or (2) using ambient light as a main source of the light.
• each pixel 100 can be individually driven by a different bit value and each pixel 100 is an independent unit of display (or a picture element)
• the resolution of the LCD in these operating modes can be made as high as three times the resolution of the LCD operating in other modes in which a composite pixel comprising multiple pixels 100 is used as an independent unit of display.
• a pixel 100 as described herein can be used as a grayscale pixel (for example, in a 2-bit-, 4-bit-, or 6-bit- gray-level reflective mode).
• three pixels 100 can form a single composite pixel of the multi-mode LCD and be collectively electronically driven by a single multi-bit signal to produce a shade of gray in the composite pixel.
• each of the pixels 100 in a composite pixel of the multi- mode LCD can be individually electronically driven by a different multi-bit signal to produce a shade of gray in each pixel 100.
• each pixel 100 can be individually driven by a different bit value and each pixel 100 is an independent unit of display
• the resolution of the LCD in these operating modes can be made as high as three times the resolution of the LCD in other operating modes in which a composite pixel comprising multiple pixels 100 is used as an independent unit of display.
• a signal may be encoded into the video signal that instructs a display driver what operating mode and what corresponding resolution to drive.
• a separate line may be used to inform the display to go into a low-power mode.
• a low field rate may be used to reduce power consumption.
• the driver IC which may be a part of, or alternatively in addition to, the latched pixel driving circuit 400 described herein, for the multi-mode LCD may run with a slow 60203-0018 liquid crystal and may comprise electronics that allow the electric charge to be held longer at a pixel.
• metal layers 110, 150 of FIG. 1 and an oxide layer may operate as additional capacitors to hold the electric charge.
• a layer of liquid crystal material 104 having a high value of ⁇ n termed a thick LC material
• Such a thick liquid crystal may switch states with a low field rate, and may have a high voltage holding ratio and long life even at the slow switching frequency.
• the 5CB liquid crystal material commercially available from Merck may be used.
• FIG. 7 illustrates an example configuration in which a multi-mode LCD (706) runs at a low field rate without flicker.
• a chipset 702 that contains a CPU (or a controller) 708 may output a first timing control signal 712 to timing control logic 710, which may be a part, or in addition to, the latched pixel driving circuit 400 described herein, in a LCD driver IC 704.
• the timing control logic 710 in turn may output a second timing control signal 704 to the multi- mode LCD 706.
• the chipset 702 may, but is not limited to, be a standard chipset that can be used to drive different types of LCD displays including the multi-mode LCD 706 as described herein.
• the driver IC 704 is interposed between the chipset 702 and the multi-mode LCD 706, and may contain specific logic to drive the multi-mode LCD in different operating modes.
• the first timing control signal 712 may have a first frequency such as 30hz
• the second timing control signal 714 may have a second frequency in relation to the first frequency in a given operating mode of the multi-mode LCD.
• the second frequency may be configured or controlled to be one half of the first frequency in the reflective mode.
• the second timing control signal 714 received by the multi-mode display 706 may be a smaller frequency than that for a standard LCD display in that mode.
• the second frequency is regulated by the timing control logic 710 to have different relationships with the first frequency depending on the operating modes of the multi- mode LCD 706. For example, in the color transmissive mode, the second frequency may be the same as the first frequency.
• the timing control signal 714 from the timing control logic 710 is of a frequency in a range of 10 hertz to 300 hertz, inclusive.

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• Chemical & Material Sciences (AREA)
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• Computer Hardware Design (AREA)
• Nonlinear Science (AREA)
• Mathematical Physics (AREA)
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• Liquid Crystal Display Device Control (AREA)
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• 2009
  • 2009-07-28 TW TW098125400A patent/TWI404038B/zh not_active IP Right Cessation
  • 2009-07-28 US US12/510,498 patent/US8462144B2/en not_active Expired - Fee Related
  • 2009-07-28 JP JP2011521241A patent/JP2011529584A/ja active Pending
  • 2009-07-28 CN CN2009801298316A patent/CN102124509A/zh active Pending
  • 2009-07-28 WO PCT/US2009/051946 patent/WO2010014598A2/en not_active Ceased
  • 2009-07-28 KR KR1020117004896A patent/KR101291670B1/ko not_active Expired - Fee Related

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