Liquid crystal display and driving method thereof

A liquid crystal display is disclosed with a reduced thickness. According to an embodiment, the liquid crystal display device includes a liquid crystal panel including upper and lower substrates and divided into an effective display region and a non-display region adjacent to the effective display region; a backlight unit configured to supply light to the effective display region; a backlight driving unit configured to control an operation of the backlight unit; a driving IC configured to control data to be displayed in the effective display region; an illuminance sensor configured to sense light external to the liquid crystal display device; and a flexible printed circuit (FPC) on which the backlight driving unit is disposed, the driving IC and the illuminance sensor being disposed adjacent to each other in the non-display region over the lower substrate.

This application claims the benefit of Korea Patent Application No. 10-2007-0138304 field on Dec. 27, 2007, which is incorporated herein by reference for all purposes as if fully set forth herein.

BACKGROUND

This document relates to a liquid crystal display, and more particularly, to a liquid crystal display which can be made slim while incorporating an illuminance sensor.

2. Related Art

In general, the scope of application of liquid crystal displays has widened due to the lightweight, thinness, and low power consumption of liquid crystal displays. According to this trend, liquid crystal displays are widely used in office automation machines and audio/video machines. The intensity of light beam is adjusted in accordance with a video signal applied to a plurality of control switches arranged in a matrix in order to display a desired picture on a screen.

Since such LCDs are non-emissive devices, the LCDs generally need a light unit such as a backlight unit. A light source for the backlight unit can include fluorescent lamps such as external electrode fluorescent lamps (EEFLs) and cold cathode fluorescent lamps (CCFLs), or a plurality of light emitting diodes (LEDs).

When using the fluorescent lamps as the backlight, device characteristics of the LCD may be easily deteriorated due to the high power consumption and high heat generation of the fluorescent lamps. In addition, the fluorescent lamps generally have a stick shape, so they do not withstand impacts well and can easily break on impact.

However, when the light emitting diodes are used as the backlight, since each light emitting diode is a semiconductor device, the lifetime of the LCD can be long, the lighting speed of the LCD can be fast, and the power consumption of the LCD can be low. The light emitting diode also withstands impacts well and miniaturization thereof is easy. Because of these benefits, there is an increasing trend that light emitting diodes are used in monitors having middle or large sized LCDs such as in computers or television sets, as well as in small sized LCDs such as in mobile telephones, as a light source.

Recently, there have been proposed LCD control methods in which the range of luminance of a displayed image can be enlarged by adjusting the brightness of the backlight and the gamma characteristics of output data. In these control methods, an illuminance sensor is mounted in a liquid crystal module to sense the illuminance of external light. Based on this sensing information, if the external illuminance is high, the amount of electric current supplied to the backlight is increased and the gamma characteristics of output data are increased, while if the external illuminance is low, the amount of electric current supplied to the backlight is decreased and the gamma characteristics of output data are lowered. By this, the power consumption of the backlight can be reduced, and the visibility for users can be greatly improved.

FIG. 1is a schematic view of an illuminance sensor according to the related art.

As shown inFIG. 1, a conventional illuminance sensor20is generally manufactured in a package24type so that a sensor portion26can be easily exposed to the external light, and then mounted in a printed circuit board22(hereinafter, “PCB”).

FIG. 2shows a mobile phone which employs the illuminance sensor ofFIG. 1.

As shown inFIG. 2, the mobile phone having an illuminance sensor20mounted in a PCB, senses external light through a hole32, and adjusts the brightness of the backlight and the gamma characteristics of output data based on the sensed external light. However, in the case that a package type illuminance sensor is mounted in a PCB as seen inFIG. 1, it is necessary to provide much additional space for the mounting area of the illuminance sensor, which makes it difficult to produce slim liquid crystal displays, e.g., for use in mobile phones.

Moreover, the conventional liquid crystal display having a package type illuminance sensor mounted in the PCB has other disadvantages in that, because of spacing distances between the illuminance sensor and a driving integrated circuit (hereinafter, “driving IC”) and between the illuminance sensor and a driving portion, additionally long wiring is needed in order to link or transmit the sensing information from the illuminance sensor to the driving IC and the backlight driving portion. This can complicate the configuration of liquid crystal displays, increase the cost of manufacturing liquid crystal displays, and limits manufacturing of slim liquid crystal displays.

SUMMARY

An aspect of this document is to provide a liquid crystal display which can be made slim while incorporating an illuminance sensor.

Another aspect of this document is to provide a liquid crystal display which reduces the length of a communication line for electrically connecting an illuminance sensor with a driving IC, and/or electrically connecting the illuminance sensor with a backlight driving portion of the liquid crystal display.

Another aspect of this document is to provide a liquid crystal display and a method of forming the same, which address the limitations and disadvantages associated with the related art.

To achieve the above advantages, a liquid crystal display in accordance with one embodiment of the present invention comprises: a liquid crystal panel having an effective display region for displaying an image and a non-display region for not displaying the image; a backlight unit for radiating light on the back surface of the liquid crystal panel; an illuminance sensor for sensing external light radiated on the front surface of the liquid crystal panel; a driving IC for adjusting a gamma characteristic of data to be displayed on the liquid crystal panel based on sensing information from the illuminance sensor; a PCB for generating a driving signal required to drive the liquid crystal panel; a FPC for electrically connecting the PCB to the driving IC; a backlight driving portion for adjusting a driving current supplied to the backlight unit based on the sensing information from the illuminance sensor; and a communication line for electrically connecting between the illuminance sensor and the driving IC and between the illuminance sensor and the backlight driving portion, wherein the illuminance sensor is mounted on the non-display region by a COG method, and is arranged adjacent to the driving IC.

According to an embodiment, the driving IC is mounted on the non-display region by the COG method, and the backlight driving portion is mounted on the FPC by a SMT method. The communication line can be an I2C communication line.

A liquid crystal display in accordance with another embodiment of the present invention comprises: a liquid crystal panel having an effective display region for displaying an image and a non-display region for not displaying the image; a backlight unit for radiating light on the back surface of the liquid crystal panel; an illuminance sensor for sensing external light radiated on the front surface of the liquid crystal panel; a driving IC for adjusting a gamma characteristic of data to be displayed on the liquid crystal panel based on sensing information from the illuminance sensor; a PCB for generating a driving signal required to drive the liquid crystal panel; a FPC for electrically connecting the PCB to the driving IC, and having an extended portion extended from one side thereof so as to be overlapped with part of the non-display region; a backlight driving portion for adjusting a driving current supplied to the backlight unit based on the sensing information from the illuminance sensor; and a communication line for electrically connecting between the illuminance sensor and the driving IC and between the illuminance sensor and the backlight driving portion, wherein the illuminance sensor is mounted on the extended portion by a SMT method and is arranged adjacent to the driving IC on the non-display region.

A liquid crystal display in accordance with still another embodiment of the present invention comprises: a liquid crystal panel having an effective display region for displaying an image and a non-display region for not displaying the image; a backlight unit for radiating light on the back surface of the liquid crystal panel; an illuminance sensor for sensing external light radiated on the front surface of the liquid crystal panel; a driving IC mounted on the non-display region by a COG method to adjust a gamma characteristic of data to be displayed on the liquid crystal panel based on sensing information from the illuminance sensor; a PCB for generating a driving signal required to drive the liquid crystal panel; a FPC for electrically connecting the PCB to the driving IC; a backlight driving portion for adjusting a driving current supplied to the backlight unit based on the sensing information from the illuminance sensor; and a communication line for electrically connecting between the illuminance sensor and the driving IC and between the illuminance sensor and the backlight driving portion, wherein the illuminance sensor is mounted on the FPC by a SMT method, and is arranged on the FPC adjacent to the backlight driving portion.

A liquid crystal display in accordance with still another embodiment of the present invention comprises: a liquid crystal panel having an effective display region for displaying an image and a non-display region for not displaying the image; a backlight unit for radiating light on the back surface of the liquid crystal panel; an illuminance sensor for sensing external light radiated on the front surface of the liquid crystal panel; a driving IC mounted on the non display region by a COG method to adjust a gamma characteristic of data to be displayed on the liquid crystal panel based on sensing information from the illuminance sensor; a FPC electrically connected to the driving IC; a PCB mounted on the FPC to generate a driving signal required to drive the liquid crystal panel; a backlight driving portion for adjusting a driving current supplied to the backlight unit based on the sensing information from the illuminance sensor; and a communication line for electrically connecting between the illuminance sensor and the driving IC and between the illuminance sensor and the backlight driving portion, wherein the illuminance sensor is mounted on the PCB by a SMT method, and is arranged on the FPC adjacent to the backlight driving portion.

A liquid crystal display in accordance with still another embodiment of the present invention comprises: a liquid crystal panel including upper and lower substrates and divided into an effective display region and a non-display region adjacent to the effective display region; a backlight unit configured to supply light to the effective display region; a backlight driving unit configured to control an operation of the backlight unit; a driving IC configured to control data to be displayed in the effective display region; an illuminance sensor configured to sense light external to the liquid crystal display device; and a flexible printed circuit (FPC) on which the backlight driving unit is disposed, the driving IC and the illuminance sensor being disposed adjacent to each other in the non-display region over the lower substrate.

A liquid crystal display in accordance with still another embodiment of the present invention comprises: a liquid crystal panel including upper and lower substrates and divided into an effective display region and a non-display region adjacent to the effective display region; a backlight unit configured to supply light to the effective display region; a backlight driving unit configured to control an operation of the backlight unit; a driving IC disposed in the non-display region over the lower substrate and configured to control data to be displayed in the effective display region; an illuminance sensor configured to sense light external to the liquid crystal display device; and a flexible printed circuit (FPC) on which the backlight driving unit is disposed, the illuminance sensor and the backlight driving unit being disposed adjacent to each other over the FPC.

DETAILED DESCRIPTION

Hereinafter, embodiments of the invention will be described in detail with reference toFIGS. 3 to 8as non-limiting examples.

FIG. 3is a plane view of a liquid crystal display in accordance with a first embodiment of the present invention.FIG. 4is a perspective view of an example of a portion of the liquid crystal display ofFIG. 3in accordance with the first embodiment of the present invention.

Referring toFIGS. 3 and 4, a liquid crystal display100in accordance with the first embodiment of the present invention includes a liquid crystal panel103, a backlight unit120for radiating light on the liquid crystal panel103, an illuminance sensor130mounted on the liquid crystal panel103to sense external light, a driving IC116for adjusting gamma characteristic(s) of data to be displayed on the liquid crystal panel103based on sensing information from the illuminance sensor130, a PCB170arranged on the back surface of the liquid crystal panel103to generate a drive signal for driving the liquid crystal panel103, a flexible printed circuit (hereinafter, “FPC”) for electrically connecting the PCB170to the driving IC116of the liquid crystal panel103, and a backlight driving portion150mounted on the FPC140to adjust the brightness of the backlight unit120based on the sensing information from the illuminance sensor130.

The liquid crystal display100further includes a bottom cover for housing and supporting the backlight unit120and a top case for covering the edges of the liquid crystal panel103and the sides of the bottom cover.

The liquid crystal panel103includes a spacer (not shown) for interposing liquid crystal between a lower substrate102and an upper substrate104and maintaining a constant gap between the upper substrate104and the lower substrate102. Color filters, black matrices, and so on, are formed on the upper substrate104of the liquid crystal panel103, but may be formed on the lower substrate102as needed. Signal lines, such as data lines and gate lines, are formed on the lower substrate102of the liquid crystal panel103, and thin film transistors (hereinafter, “TFTs”) are formed at intersections between the gate lines and the data lines. The TFTs switch a data signal to be transmitted toward the liquid crystal cell from the data lines in response to a scanning signal from the gate lines. Pixel electrodes are formed at pixel regions between the data lines and the gate lines. A common electrode facing the pixel electrodes may be formed on the upper substrate104or the lower substrate102depending on the method of applying an electric field to the liquid crystal cell. The liquid crystal panel103of this type and other types includes an effective display region A for displaying an image and a non-display region B for not displaying the image. The gray scale of the image displayed on the effective display region A can be differently implemented according to gate signals and data signals supplied from the driving IC116mounted on the non-display region B.

The driving IC116is preferably mounted on the non-display region B of the liquid crystal panel103by a chip-on-glass (hereinafter, referred to as “COG”) method, but other suitable method may be used. Unlike a tape automated bonding (hereinafter, referred to as “TAB”) method, the COG method is a method of directly mounting the driving IC116on the lower substrate102of the liquid crystal panel103for electrical conduction. The driving IC116adjusts the gamma characteristics of data to be displayed on the liquid crystal panel103based on sensing information from the illuminance sensor130. In other words, to increase the visibility for users according to external illuminance, if the external illuminance is high, the driving IC116increases the gamma characteristics of output data based on the sensing information output from the illuminance sensor130, while, if the external illuminance is low, it decreases the gamma characteristics of output data based on the sensing information from the illuminance sensor130.

The illuminance sensor130is mounted, along with the driving IC116, on the non-display region B of the liquid crystal panel103, by preferably the COG method, but other suitable method may be used. Preferably, the illuminance sensor130is arranged adjacent to the driving IC116in order to reduce the length of a communication line(e.g., wiring, conductive lines, ect.) used in providing communications with he driving IC116. The illuminance sensor130senses the external light (e.g., level of the external light) and thereby supplies sensing information according to the sensed external illuminance to the driving IC116and the backlight driving portion150through. e.g., an inter-integrated circuit (I2C)communication line180.

The PCB170is arranged on the back surface of the liquid crystal panel103and generates a drive signal for driving the liquid crystal panel103.

The FPC140includes a base film layer formed of, e.g., polyimide thereunder, a conductive layer formed of a conductive material having a predetermined width on top of the base film layer, and a cover film layer formed of, e.g., polyamide on top of the conductive layer. Other suitable materials of the FPC140may be used.

After the coupling of the liquid crystal panel103and the bottom cover, the FPC140is electrically connected to pad electrodes of the driving IC116by using an anisotropic conductive film (hereinafter, referred to as “ACF”) as the medium. Further, the FPC140is curved twice at the sides of the coupled liquid crystal panel103and bottom cover, and then electrically connected to the PCB170arranged on the back surface of the bottom cover. For example, because the FPC140is flexible, the FPC140can start from the top of the lower substrate102and then wrap around one side of the lower substrate102and the backlight unit120to the back of the panel for connecting with the PCB103on the back of the panel.

The backlight driving portion150is mounted on the FPC140by preferably a SMT (Surface Mounting Technology), but other suitable method may be used. The backlight driving portion150is supplied with sensing information from the illuminance sensor130through the I2C communication line180. The backlight driving portion150adjusts the amount of electric current supplied to the backlight unit120based on the sensing information. For example, to reduce the power consumed in the backlight unit120, based on the sensing information from the illuminance sensor130, if the external illuminance (e.g., surrounding light external to a device having the liquid crystal display, etc.) is detected to be high, the backlight driving portion150can increase the amount of electric current supplied to the backlight unit120, while, if the external illuminance is detected to be low, it can decrease the amount of electric current supplied to the backlight unit120. The backlight driving portion150supplies a backlight driving current to the backlight unit120through a drive signal supply line160. In a non-limiting example, since the FPC140may wrap around the panel, the backlight driving portion150may be disposed on the FPC140on a front, side, or back side of the panel.

The backlight unit120can include a plurality of light sources for radiating light on the liquid crystal panel103, a reflective sheet arranged at one sides of the light sources, a light guiding plate for converting the light incident from the light sources into surface light sources, and a plurality of optical sheets arranged between the liquid crystal panel103and the conductive plate. As the light sources, white LEDs (light emitting diodes) may be used. The reflective sheet plays the role of guiding the light generated from the light sources toward the liquid crystal panel103, and the light guiding plate plays the role of converting the light from the light sources into surface light sources. The optical sheets play the role of vertically raising the light incident at an inclination from the surface of the reflective sheet and making the light proceed toward the liquid crystal panel103. Other types of backlight unit can be used as the backlight unit120.

The liquid crystal display100(and liquid crystal displays200,300,400to be discussed below) can include other components of conventional liquid crystal displays. All components of the liquid crystal display100(and liquid crystal displays200,300,400) are operatively coupled and configured.

The above-described liquid crystal display in accordance with the first embodiment of the present invention has the driving IC116and the illuminance sensor130which are mounted adjacent to the non-display region B of the liquid crystal panel103by the COG method, and the backlight driving portion150mounted on the FPC140adjacent to the above components116and130by the SMT method. Consequently, the liquid crystal display in accordance with the first embodiment of the present invention is able to incorporate the illuminance sensor130, has a slim thickness, and greatly reduces the length of the I2C communication line180for electrically connecting between the illuminance sensor130and the driving IC116and between the illuminance sensor130and the backlight driving portion150.

FIG. 5is a plane view of a liquid crystal display in accordance with a second embodiment of the present invention.FIG. 6is a perspective view of an example of a portion of the liquid crystal display ofFIG. 5in accordance with the second embodiment of the present invention.

Referring toFIGS. 5 and 6, the liquid crystal display100in accordance with the second embodiment of the present invention can include a liquid crystal panel203, a backlight unit220for radiating light on the liquid crystal panel203, an illuminance sensor230mounted on the liquid crystal panel203to sense external light, a driving IC216for adjusting gamma characteristic(s) of data to be displayed on the liquid crystal panel203based on sensing information from the illuminance sensor230, a PCB270arranged on the back surface of the liquid crystal panel203to generate a drive signal for driving the liquid crystal panel203, a FPC240for electrically connecting the PCB270to the driving IC216of the liquid crystal panel203, and a backlight driving portion250mounted on the FPC240to adjust the brightness of the backlight unit220based on the sensing information from the illuminance sensor230. The liquid crystal display200can further include a bottom cover for housing and supporting the backlight unit220and a top case for covering the edges of the liquid crystal panel203and the sides of the bottom cover.

The liquid crystal panel203includes a spacer for interposing liquid crystal between a lower substrate202and an upper substrate204and maintaining a constant gap between the upper substrate204and the lower substrate202. Color filters, black matrices, and so on, which are not shown, can be formed on the upper and/or lower substrate202,204of the liquid crystal panel203. Signal lines, such as data lines and gate lines are formed on the lower substrate202of the liquid crystal panel203, and TFTs are formed at intersections between the gate lines and the data lines. The TFTs switch a data signal to be transmitted toward the liquid crystal cell from the data lines in response to a scanning signal from the gate lines. Pixel electrodes are formed at pixel regions between the data lines and the gate lines. A common electrode facing the pixel electrodes may be formed on the upper substrate204or the lower substrate202depending on the method of applying an electric filed to the liquid crystal cell. The liquid crystal panel203of this type includes an effective display region A for displaying an image and a non-display region B for not displaying the image. The gray scale of the image displayed on the effective display region A is differently implemented according to gate signals and data signals supplied from the driving IC216mounted on the non-display region B.

The driving IC216is mounted on the non-display region B of the liquid crystal panel203by a COG method or other suitable method. Unlike a TAB method, the COG method is a method of directly mounting the driving IC216on the lower substrate202of the liquid crystal panel203for electrical conduction. The driving IC216adjusts the gamma characteristics of data to be displayed on the liquid crystal panel203based on sensing information from the illuminance sensor230. In other words, to increase the visibility for users according to external illuminance, if the external illuminance is high, the driving IC216can increase the gamma characteristic of output data based on the sensing information from the illuminance sensor230, while, if the external illuminance is low, it can decrease the gamma characteristic of output data based on the sensing information from the illuminance sensor230.

The PCB270is preferably arranged on the back surface of the liquid crystal panel203and generates a drive signal for driving the liquid crystal panel203.

The FPC240can be composed of a base film layer formed of, e.g., polyimide thereunder, a conductive layer formed of a conductive material having a predetermined width on top of the base film layer, and a cover film layer formed of, e.g., polyamide on top of the conductive layer. After the coupling of the liquid crystal panel203and the bottom cover, the FPC240is electrically connected to pad electrodes of the driving IC216by using an AFC as the medium.

Unlike the first embodiment, the FPC240has an extended portion C extended to a portion, other than the portion where the driving IC216is mounted, of the non-display region B. For instance, the illuminance sensor230is disposed directly on the extended portion C of the FPC240while the driving IC216(adjacent to the illuminance sensor230) is not disposed directly on any portion of the FPC240but is disposed directly on a surface of the lower substrate202. The illuminance sensor230can be mounted on the extended portion C by a SMT mounting method or other suitable method. Further, the FPC240is curved twice (e.g., wrapped around) at the sides of the coupled liquid crystal panel203and bottom cover, and then electrically connected to the PCB270arranged on the hack surface of the bottom cover.

The illuminance sensor230can be mounted by the SMT mounting technology on the extended portion C of the FPC240overlapped and connected with the non-display region B of the liquid crystal panel203. Preferably, the illuminance sensor230is arranged adjacent to the driving IC216in order to reduce the length of a communication line used in communication with the driving IC216. The illuminance sensor230detects the external light and thereby generates and supplies sensing information according to the detected external light, to the driving IC216and the backlight driving portion250through an I2C communication line280.

The backlight driving portion250is mounted on the FPC240by the SMT mounting technology, but may be disposed using other suitable method. The backlight driving portion250is supplied with the sensing information from the illuminance sensor230through the I2C communication line280. The backlight driving portion250adjusts the amount of electric current supplied to the backlight unit220based on the sensing information. In other words, to reduce the power consumed in the backlight unit220based on the sensing information from the illuminance sensor230, if the external illuminance/light is detected to be high, the backlight driving portion250can increase the amount of electric current supplied to the backlight unit220, while, if the external illuminance/light is detected to be low, the backlight driving portion250can decrease the amount of electric current supplied to the backlight unit220. The backlight driving portion250supplies a backlight driving current to the backlight unit220through a drive signal supply line260.

The backlight unit220can include a plurality of light sources for radiating light on the liquid crystal panel203, a reflective sheet arranged at one sides of the light sources, a light guiding plate for converting the light incident from the light sources into surface light sources, and a plurality of optical sheets arranged between the liquid crystal panel203and the conductive plate. As the light sources, white LEDs (light emitting diodes) may be used. The reflective sheet plays the role of guiding the light generated from the light sources toward the liquid crystal panel203, and the light guiding plate plays the role of converting the light from the light sources into surface light sources. The optical sheets play the role of vertically raising the light incident at an inclination from the surface of the reflective sheet and making the light proceed toward the liquid crystal panel203. Other types of backlight unit may be used.

The above-described liquid crystal display in accordance with the second embodiment of the present invention has the driving IC216mounted by the COG method on the non-display region B of the liquid crystal panel203, the illuminance sensor230mounted by the SMT method on the extended portion C of the FPC240extended to a portion, excluding the portion where the driving IC216is mounted, of the non-display region B, and the backlight driving portion250mounted on the FPC240adjacent to the above components216and230by the SMT method.

Consequently, the liquid crystal display in accordance with the second embodiment of the present invention is able to incorporate the illuminance sensor230, has a slim thickness, and greatly reduces the length of the I2C communication line280used for electrically connecting between the illuminance sensor230and the driving IC216and between the illuminance sensor230and the backlight driving portion250.

FIG. 7is a plane view of a liquid crystal display in accordance with a third embodiment of the present invention.

Referring toFIG. 7, the liquid crystal display300in accordance with the third embodiment of the present invention is substantially the same as the liquid crystal display200in accordance with the second embodiment, except for the shape of a FPC340and the mounting method and mounting position of an illuminance sensor330. Thus, the other components are given the same reference numerals as those of the liquid crystal display200in accordance with the second embodiment, and a detailed description thereof will be omitted. The third embodiment may substitute for the second embodiment in the case that, in the second embodiment, the width of the region, other than the region where the driving IC216is mounted, of the non-display region B is too small to mount the illuminance sensor330thereon, or the height of the illuminance sensor330to be mounted is relatively greater than that of the driving IC216.

The FPC340can include base film layer formed of, e.g., polyimide thereunder, a conductive layer formed of a conductive material having a predetermined width on top of the base film layer, and a cover film layer formed of, e.g., polyamide on top of the conductive layer. After the coupling of the liquid crystal panel203and the bottom cover, the FPC340is electrically connected to pad electrodes of the driving IC216by using an AFC as the medium.

Unlike the second embodiment, the FPC340has no extended portion C. Further, the FPC340is curved twice (wrapped around) at the sides of the coupled liquid crystal panel203and bottom cover, and then electrically connected to a PCB arranged on the back surface of the bottom cover. The backlight driving portion250is disposed on the FPC340and as a result, may be disposed on the top side of bottom side of the panel.

The illuminance sensor330is mounted by the SMT mounting technology or other suitable method on the FPC340not overlapped with the non-display region B of the liquid crystal panel203. The illuminance sensor330can be arranged adjacent to or close to the driving IC216in order to reduce the length of a communication line used in communication with the driving IC216. Further, the illuminance sensor330is disposed adjacent to the backlight driving unit250, both on the FPC340, outside the non-display region B. The illuminance sensor330supplies sensing information according to external illuminance to the driving IC216and the backlight driving portion250through an I2C communication line380.

The above-described liquid crystal display300in accordance with the third embodiment of the present invention has the driving IC216mounted by the COG method on the non-display region B of the liquid crystal panel203, and the illuminance sensor330and the backlight driving portion250mounted on the FPC340adjacent to the driving IC216by the SMT method. Consequently, the liquid crystal display in accordance with the third embodiment of the present invention is able to incorporate the illuminance sensor330, has a slim thickness, and greatly reduces the length of the I2C communication line380used for electrically connecting between the illuminance sensor330and the driving IC216and between the illuminance sensor330and the backlight driving portion250.

FIG. 8is a plane view of a liquid crystal display in accordance with a fourth embodiment of the present invention.

Referring toFIG. 8, the liquid crystal display400in accordance with the fourth embodiment of the present invention is substantially the same as the liquid crystal display300in accordance with the third embodiment, except for the arrangement position of a PCB470and the mounting position of an illuminance sensor430. Thus, the other components are given the same reference numerals as those of the liquid crystal display300in accordance with the third embodiment, and a detailed description thereof will be omitted. The fourth embodiment may substitute for the third embodiment in the case that, in the third embodiment, it is difficult to directly mounted the illuminance sensor430on the FPC340.

The PCB470is mounted by the SMT mounting technology on the FPC340, outside the non-display region B of the liquid crystal panel203, and generates a drive signal used to drive the liquid crystal panel203. The drive signal is supplied to the driving IC216of the liquid crystal panel203via the FPC340.

The illuminance sensor430is mounted on the PCB470. For instance, the illuminance sensor430may be disposed directly on the PCB470, and the PCB470may be disposed on the FPC340. The backlight driving portion250is disposed on the FPC340and as a result, may be disposed on a top side or bottom side of the panel.

Preferably, the illuminance sensor430is arranged adjacent to the backlight driving portion250in order to reduce the length of a communication line used to connect between the driving IC216and the backlight driving portion250. The illuminance sensor430supplies sensing information according to external illuminance to the driving IC216and the backlight driving portion250through the I2C communication line380.

The above-described liquid crystal display in accordance with the fourth embodiment of the present invention has the driving IC216mounted by the COG method on the non-display region B of the liquid crystal panel203and the PCB470incorporating the illuminance sensor430and the backlight driving portion250mounted on the FPC340adjacent to the driving IC216by the SMT method. Consequently, the liquid crystal display in accordance with the fourth embodiment of the present invention is able to incorporate the illuminance sensor430, has a slim thickness, and reduces the length of the I2C communication line380used for electrically connecting between the illuminance sensor430and the driving IC216and between the illuminance sensor430and the backlight driving portion250.

As described above, in the liquid crystal display in accordance with embodiments of the present invention, an illuminance sensor can be mounted on the non-display region adjacent to the driving IC by a COG method or other suitable method, or mounted on the FPC adjacent to the backlight driving portion by a SMT method or other suitable method.

For example, according to the embodiments, the driving IC and the illuminance sensor are disposed adjacent to each other in the non-display region over the lower substrate of the liquid crystal panel. In one example, the illuminance sensor is formed directly on the lower substrate of the liquid crystal panel in the non-display region. In another example, the illuminance sensor is formed directly on the FPC in the non-display region.

According to other embodiments, the illuminance sensor and the backlight driving unit are disposed adjacent to each other over the FPC. In one example, the illuminance sensor is formed directly on the FPC. In another example, the illuminance sensor is formed directly on the PCB disposed on the FPC.

Furthermore, the features and components discussed in any of the embodiments may be applied to any other embodiments of the invention, or may be combined with each other. Moreover, although specific methods (e.g., SMT, COG, etc.) have been discussed, the invention encompasses use of other suitable methods to form the above discussed structures of the liquid crystal displays. In addition, the components that correspond to the display region (e.g., pixels, color filters, black matrix, etc.) of the upper and lower substrates can vary depending on the display type or configuration, which are all covered by the present invention.

Consequently, the liquid crystal display is able to incorporate the illuminance sensor, has a reduced thickness, and greatly reduces the length of an I2C communication line (or other line) used for providing electrical connections among one or more of the illuminance sensor, the driving IC, the illuminance sensor, and the backlight driving portion.

It will be understood by those skilled in the art that various changes and modifications may be applicable within a range not departing from the technical idea of the invention. Accordingly, the technical scope of the present invention is not limited to the detailed description of the specification, but should be defined by the accompanying claims.