KR100965141B1 - Display device and display system - Google Patents

Abstract

A display device and a display system are disclosed. The display device includes a light sensing element that recognizes the sensing light provided by the user and generates a position signal according to the position of the sensing light. The position signal generated by the light sensing element is provided to the information processing device connected to the display device. The photosensitive device is disposed at a position where a transparent pattern is formed to transmit the sensing light as it is without loss of light, thereby improving the brightness of the image generated from the display device and greatly improving the optical recognition rate of the photosensitive device. And improve the display quality.

Description

Display and Display System {DISPLAY DEVICE AND DISPLAY SYSTEM}

1 is a partial cutaway perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

Figure 2 is a cross-sectional view taken along the A ₁ -A ₂ in Fig.

3 is a plan view conceptually illustrating a portion of the first substrate illustrated in FIG. 1.

4 is a cross-sectional view of a first pixel area and a second pixel area of the first substrate illustrated in FIG. 3.

FIG. 5 is an enlarged plan view of the photosensitive device of FIG. 3.

6 is a plan view conceptually showing another embodiment of a liquid crystal display according to the present invention.

7 is a cross-sectional view conceptually showing another embodiment of a liquid crystal display according to the present invention.

8 is a conceptual diagram illustrating a liquid crystal display system according to an embodiment of the present invention.

9 is a conceptual diagram of a liquid crystal display system according to another embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and a display system, and more particularly, to a display device and a display system in which the display quality is improved by greatly improving the optical recognition rate of a photosensitive device disposed between pixels.

In general, a display device converts an electrical signal applied from an information processing device into an image. Conventional display apparatuses and information processing apparatuses are only capable of one-way communication. Therefore, in order to display a new image from the display apparatus, a data input apparatus for inputting information into the information processing apparatus, for example, a keyboard, a keypad, a mouse, or the like is required.

Some of the recently developed display apparatuses have a function of reconstructing an image by directly inputting the image on a screen on which an image is displayed and outputting information to the information processing apparatus. In other words, this means that the bidirectional communication between the display device and the information processing device is enabled.

The conventional display device further includes a touch screen panel for bidirectional communication between the display device and the information processing device. The touch screen panel changes the pressure applied by the operator's hand or a touch pen into position data and outputs the position data to the information processing apparatus. The information processing apparatus processes the position data input from the display apparatus to output a new image signal to the display apparatus, and the display apparatus displays the new image corresponding to the image signal.

However, due to the touch panel, the display device has a problem in that thickness and weight are increased. In addition, a display device using a touch panel has a problem that is unsuitable for expressing precise characters or pictures.

Recently, a light sensing liquid crystal display device that detects light input by an operator to output a location information signal and communicates bidirectionally with an information processing device has been developed. Such a photosensitive liquid crystal display has a built-in photosensitive sensor that detects light and outputs a signal having position information together with pixels displaying an image.

The light sensor detects the light input by the operator and outputs a signal that can be recognized by the information processing device, and the output signal is transmitted to the information processing device. The information processing apparatus outputs a new image signal to the photosensitive liquid crystal display in response to the signal input from the photosensitive liquid crystal display, and the photosensitive liquid crystal display displays the new image by the image signal.

On the other hand, a light pen is required to apply light to a liquid crystal display having a pixel and a light sensing sensor. The light pen has a light source for generating high brightness light. A red light emitting diode having a high optical recognition rate is used as a light source of the light pen, and the light emitting diode is disposed at one end of the light pen facing the liquid crystal display.

However, in the conventional photosensitive liquid crystal display device, a considerable amount of light emitted from the light pen is lost while passing through the color filter and the organic layer protecting the pixels and the photosensitive sensors, and enter the photosensitive sensor. The amount of light entering is reduced. As a result, there is a problem in that the sensing sensitivity of the photosensitive sensors is lowered and the photosensitive liquid crystal display is malfunctioning.                         

In addition, since parts such as a light emitting diode and a power supply unit are built in the light pen for applying light to the light sensing unit, the production cost is increased, and the weight and volume of the light pen are increased. In addition, since the power supply unit for supplying power to the light emitting diode is a consumable part, there is a need to frequently replace the power supply unit.

Accordingly, the present invention has been made in view of such a conventional problem, and a first object of the present invention is to provide a display device in which malfunction is prevented by increasing the recognition rate of light inputted on the display panel by light.

A second object of the present invention is to provide a display system for converting image light generated in the display device into sensing light by a light pen and inputting information to the display device.

In order to realize the first object of the present invention, the present invention improves the luminance of a color image by transmitting white light through a first pixel region displaying a color image by filtering out white light and emitting red, green and blue light, respectively. A first filter including a color filter disposed in the second pixel region, the first pixel region and the second pixel region, and an optical sensing element disposed under the color filter in the second pixel region and outputting a detection signal by sensing light; A substrate, a second substrate coupled to face the first substrate, a liquid crystal layer interposed between the first substrate and the second substrate, and disposed in each of the first and second pixel regions to control the liquid crystal contained in the liquid crystal layer A display device includes a first electrode and a second electrode spaced apart from the first electrode to generate an electric field.                     

In addition, in order to implement the second object of the present invention, the first pixel area for filtering the white light to emit red, green and blue light respectively to display a color image, the second to transmit the white light to improve the brightness of the color image A first substrate including a color filter disposed in a pixel region, a first pixel region and a second pixel region, and an optical sensing element disposed under the color filter in the second pixel region and outputting a detection signal by sensing light; A second substrate coupled to the first substrate, a liquid crystal layer interposed between the first substrate and the second substrate, and a first disposed in each of the first and second pixel regions for controlling the liquid crystal contained in the liquid crystal layer A liquid crystal display including an electrode and a second electrode spaced from the first electrode to generate an electric field, and light for converting red, green, blue light and white light emitted from the first substrate into sensing light. A display system including a light pen including a converter is provided.

According to the present invention, the optical recognition rate of the optical sensing element which is embedded in the display device and transmits the information input by the user to the information processing device is further improved to improve the quality of the display device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present invention, the liquid crystal display device, which is preferably one of the display devices, is described as an embodiment, but the present invention can be widely used for other display devices, for example, an organic light emitting display device, a plasma display device, and the like.

LCD Display

1 is a partial cutaway perspective view of a liquid crystal display according to an exemplary embodiment of the present invention. Figure 2 is a cross-sectional view taken along the A ₁ -A ₂ in Fig. 3 is a plan view conceptually illustrating a portion of the first substrate illustrated in FIG. 1.

1 and 2, the liquid crystal display device 800 includes a first substrate 100, a second substrate 200, a liquid crystal layer 300, and first and second electrodes 190 and 290. .

Referring to FIG. 3, the first substrate 100 includes a transparent glass substrate. The first substrate 100 includes a first effective display area 110 and a first non-effective display area 120. The first invalid display area 120 surrounds the first effective display area 110.

The first effective display area 110 of the first substrate 100 includes a first pixel region 150 and a second pixel region 160.

The first pixel region 150 and the second pixel region 160 of the first substrate 100 may include a first driving signal line 133 for driving the first thin film transistor 130 and the first thin film transistor 130; The second driving signal line 135 is included.

4 is a cross-sectional view of a first pixel area and a second pixel area of the first substrate illustrated in FIG. 3.

3 and 4, the first thin film transistor 130 includes a first gate electrode G1, a first source electrode S1, a first channel layer C1, and a first drain electrode D1. do. The first gate electrode G1 is insulated from the first channel layer C1 and changes the electrical characteristics of the first channel layer C1 from a nonconductor to a conductor. The first source electrode S1 and the first drain electrode D1 are electrically connected to the first channel layer C1.

The first driving signal line 133 is connected to the first gate electrode G1, and the second driving signal line 135 is connected to the first source electrode S1. The first driving signal line 133 applies a first driving voltage equal to or greater than a threshold voltage of the first channel layer C1 to the first gate electrode G1. The second driving signal line 135 applies the second driving voltage to the first source electrode S1.

In operation, the second driving voltage is applied to the first source electrode S1 through the second driving signal line 135. Subsequently, a first driving voltage is applied to the first gate electrode G1 through the first driving signal line 133, so that electrical characteristics of the first channel layer C1 are changed from a non-conductor to a conductor. Therefore, the second driving voltage is output to the first drain electrode D1 through the first channel layer C1.

FIG. 5 is an enlarged plan view of the photosensitive device of FIG. 3.

4 and 5, the second pixel region 160 of the first substrate 100 may include light along with the first thin film transistor 130, the first driving signal line 133, and the second driving signal line 135. The sensing device 170 further includes. The photosensitive device 170 recognizes light, for example, red light, green light, blue light, or white light, and outputs a light sensing signal including position data.

The photosensitive device 170 includes a second thin film transistor 172, a third thin film transistor 173, a first signal line 175, and a second signal line 177.

The first signal line 175 is disposed in parallel with the first driving signal line 133, and the second signal line 177 is disposed in parallel with the second driving signal line 135. A bias voltage of a predetermined level is applied to the first signal line 175, and an optical sensing signal is output to the second signal line 177. C _st is the storage capacitance.

The second thin film transistor 172 and the third thin film transistor 173 are disposed in an area surrounded by the first signal line 175, the first driving signal line 133, the second signal line 177, and the second driving signal line 135. Is placed.

The second thin film transistor 172 includes a second gate electrode G2, a second source electrode S2, a second channel layer C2, and a second drain electrode D2. The second gate electrode G2 is insulated from the second channel layer C2. The second source electrode S2 and the second drain electrode D2 are electrically connected to the second channel layer C2. The second gate electrode G2 is electrically connected to the first signal line 175, and the second source electrode S2 is electrically connected to the second driving signal line 135. At this time, the second channel layer C2 is changed from the non-conductor to the conductor by light.

The second thin film transistor 172 includes a third gate electrode G3, a third source electrode S3, a third channel layer C3, and a third drain electrode D3. The third gate electrode G3 is insulated from the third channel layer C3 and changes the electrical characteristics of the third channel layer C3 from a nonconductor to a conductor. The third source electrode S3 and the third drain electrode D3 are electrically connected to the third channel layer C3. The third gate electrode G3 is electrically connected to the first driving signal line 133, the third source electrode S3 is electrically connected to the second drain electrode D2, and the third drain electrode D3 is It is electrically connected to the second signal line 177.

One photosensitive device 170 having the above configuration is formed for each of the plurality of second pixel regions 160.

The photosensitive signal is output to the second signal line 177 of the photosensitive device 170. The light detection signal is input to a detection signal processing module (not shown) that processes the light detection signal, and the detection signal processing module generates an image control signal. The image control signal is again applied to an information processing device (not shown) connected to the liquid crystal display device 800, and the information processing device applies new image data to the liquid crystal display device 800 according to the image control signal.

Referring to FIGS. 2 and 4 again, a color filter 180 is formed in the first pixel region 150 and the second pixel region 160 to display a full-color image. Edge portions of the color filters 180 overlap with each other between the first pixel region 150, the first pixel region 150, and the second pixel region 160. An overlapped portion of the color filter 180 blocks light leaked between the first and second pixel areas 150 and 160. Therefore, when the color filters 180 overlap with each other between the first and second pixel regions 150 and 160, the liquid crystal display 800 leaks between the first and second pixel regions 150 and 160. It does not necessarily require a black matrix pattern to block the light.

The red color filter 181, the green color filter 183, and the blue color filter 185 are disposed in the first pixel area 150. The red color filter 181, the green color filter 183, and the blue color filter 185 formed in the first pixel region 150 are driven by the first thin film transistor 130, the first driving signal line 133, and the second driving. It is formed on top of these to cover the signal line 135. A contact hole 180a is formed in the red color filter 181, the green color filter 183, and the blue color filter 185, and each contact hole 180a includes a first drain electrode (eg, a first drain electrode) of the first thin film transistor 130. It is formed in the part corresponding to D1). The red color filter 181 emits the filtered red light from the white light, and the green color filter 183 emits the filtered green light from the white light. The blue color filter 185 emits filtered blue light from white light.

The transparent pattern 187 is disposed in the second pixel region 160. The transparent pattern 187 covers the first thin film transistor 130, the first driving signal line 133, the second driving signal line 135, and the photosensitive device 170 included in the second pixel region 160. It is formed at the top of the. The contact hole 180b is also formed in a portion of the transparent pattern 187 corresponding to the first drain electrode D1 of the first thin film transistor 130. The transparent pattern 187 passes white light as it is to improve the brightness of the image emitted from the first effective display area 110.

The red color filter 181, the green color filter 183, and the blue color filter 185 disposed in the first pixel region 150 display a color image and have a transparent pattern disposed in the second pixel region 160. 187 increases the luminance of the color image. Then, when the transparent pattern 187 is formed in the second pixel region 160 where the photosensitive device 170 is disposed, light applied to the inside of the liquid crystal display device 800 by an operator is applied to the photosensitive device 170. It is possible to prevent the loss before the flow into the can be significantly improved the optical recognition rate of the photosensitive device 170.

Referring to FIG. 2, the second substrate 200 includes a transparent glass substrate. Although not shown, the second substrate 200 includes a second effective display area and a second non-effective display area. The second invalid display area surrounds the second effective display area.

The second substrate 200 is disposed to face the first substrate 100. In the present embodiment, the first effective display area 110 faces the second effective display area and the first invalid display area 120 faces the second invalid display area.

According to the present embodiment, a black matrix 230 is disposed in the second effective display area. The black matrix 230 is formed by patterning a chromium thin film, a chromium oxide film, a black organic film, and the like formed on the second substrate 200. The black matrix 230 has a grid shape. The black matrix 230 allows light incident to the first and second pixel regions 150 and 160 to pass through the openings formed at the positions corresponding to the first and second pixel regions 150 and 160. Light passing between the first and second pixel areas 150 and 160 is blocked.

As described above, when the edges of the color filters 180 disposed in the first and second pixel regions 150 and 160 overlap each other, the light blocking pattern, that is, the black matrix 230 may not necessarily be formed. However, when the color filters 180 overlapped with each other between the first and second pixel regions 150 and 160 do not completely block light, the black matrix 230 may be formed. Then, the black matrix 230 completely blocks the light passing through the overlapped color filter 180 to improve display quality.

Referring back to FIG. 2, the first substrate 100 and the second substrate 200 having the above configuration are coupled to each other, and a liquid crystal layer is provided between the first substrate 100 and the second substrate 200. crystal layer; 300 is interposed. The liquid crystal layer 300 is not an active device that generates light by itself, but a light receiving device that receives light. The arrangement of the liquid crystal layer 300 is changed by an electric field formed by a voltage difference, and the light transmittance is changed by the arrangement. Therefore, in order to change the transmittance of light from the liquid crystal layer 300, the first electrode 190 and the second electrode 290 are required.

The first electrode 190 is disposed on the first substrate 100. The first electrode 190 is disposed on upper surfaces of the red color filter 181, the green color filter 183, the blue color filter 185, and the transparent pattern 187, respectively. The first electrode 190 is connected to the first drain electrode D1 of the first thin film transistor 130 through the contact holes 180a and 180b formed in each color filter 180. The first electrode 190 is formed by patterning a transparent and conductive tin indium oxide thin film (ITO film) or indium zinc oxide film (IZO film).

The second electrode 290 is disposed on the second substrate 200. The second electrode 290 is formed over the entire surface of the second substrate 200 to cover the black matrix 230. The second electrode 290 is formed by depositing a transparent and conductive tin indium oxide thin film (ITO film) or zinc indium oxide film (IZO film).

TN mode liquid crystal (Twist Nematic liquid crystal) or VA mode liquid crystal (Vertical Alignment mode liquid crystal) may be used for the liquid crystal layer 300 interposed between the first electrode 190 and the second electrode 290.                     

6 is a plan view conceptually showing another embodiment of a liquid crystal display according to the present invention. The first thin film transistor, the first and second driving signal lines of the liquid crystal display according to the present embodiment are the same as in the above-described embodiment. Therefore, the same members will be denoted by the same reference numerals as in the above-described embodiment, and redundant description thereof will be omitted.

Referring to FIG. 6, both the first electrode 192 and the second electrode 292 are disposed on the first substrate 100. The first electrode 192 is connected to the first drain electrode D1 of the first thin film transistor 130. As illustrated in FIG. 6, the first electrode 192 has a branch shape that is divided into a plurality of branches. The second electrode 292 is formed on the same layer as the first electrode 192. The second electrode 292 has a plurality of branched branches, and the second electrode 292 is disposed between the first electrodes 192. Therefore, the first electrode 192 and the second electrode 292 are alternately arranged.

VA mode liquid crystal is used for the liquid crystal layer 300 interposed between the first electrode 192 and the second electrode 292. The first electrode 192 and the second electrode 292 are arranged horizontally on the first substrate 100 so that the liquid crystal layer 300 is disposed under the influence of the horizontal electric field, thereby causing the liquid crystal display device 800 to The viewing angle can be further extended.

7 is a cross-sectional view conceptually showing another embodiment of a liquid crystal display according to the present invention.

Referring to FIG. 7, the first electrode 194 disposed on the top surface of each color filter 180 disposed on the first substrate 100 includes a metal electrode 194b formed by patterning a metal thin film. Alternatively, the first electrode 194 may use the transparent electrode 194a and the metal electrode 194b disposed on the top surface of the transparent electrode 194a. In this case, the metal electrode 194b may be manufactured in an irregular honeycomb form.

LCD display system

8 is a conceptual diagram illustrating a liquid crystal display system according to an embodiment of the present invention. The liquid crystal display device of the liquid crystal display system according to the present embodiment is the same as the embodiment described above. Therefore, the same members will be denoted by the same reference numerals as in the above-described embodiment, and redundant description thereof will be omitted.

Referring to FIG. 8, the liquid crystal display system 900 includes a liquid crystal display device 800 and a light pen 910. The light pen 910 includes a body 920 and a light converter 930. The light converter 930 is disposed at the end of the body 920. In the present exemplary embodiment, the light converter 930 converts the red light RL, the green light GL, the blue light BL, or the white light WL emitted from the liquid crystal display device 800 into the sensing light SL. Convert In detail, in the present exemplary embodiment, the light converter 930 reflects the red light RL, the green light GL, the blue light BL, or the white light WL emitted from the liquid crystal display device 800. The sensing light SL reflected by the light converter 930 is directed toward the inside of the liquid crystal display 800, and a part of the sensing light SL passes through the liquid crystal layer 300 and the transparent pattern 187. The photosensitive device 170 is reached. Thus, the information processing device connected to the liquid crystal display device 800 controls the screen of the liquid crystal display device 800 by accurately recognizing the position of the light incident on the liquid crystal display device 800.                     

9 is a conceptual diagram of a liquid crystal display system according to another embodiment of the present invention. The liquid crystal display device of the liquid crystal display system according to the present embodiment is the same as the embodiment described above. Therefore, the same members will be denoted by the same reference numerals as in the above-described embodiment, and redundant description thereof will be omitted.

Referring to FIG. 9, the liquid crystal display system 900 includes a liquid crystal display device 800 and a light pen 950.

The light pen 950 includes a body 960, a light converter 970, a light generating module 980, and a detector 990.

The body 960 includes an empty space therein, and an opening is formed in a portion of the body 960 facing the light generating module 980.

The light converter 970 is disposed in the body 960. The light converter 970 converts a part of the red light RL, the green light GL, the blue light BL, or the white light WL into the first sensing light SL1. The light converter 970 has a through hole formed at a portion corresponding to the opening formed in the body 960.

The light generating module 980 and the detector 990 are disposed in an empty space formed inside the body 960.

The light generating module 980 includes a light source 982, a control unit 984, a power supply 986, and a switch 988. In this embodiment, the light source 982 is a light emitting diode (LED) having a small size and high luminance. The second sensing light SL2 is emitted from the light source 982. The power supply 986 provides a power source for generating the second sensing light SL2 to the light source 982. The control unit 984 controls the lighting and turning off of the light source 982.

The detector 990 is disposed in an inner empty space of the body 960 and is connected to the control unit 984 to transmit a detecting signal to the control unit 984. The detector 990 converts an analog signal such as red light RL, green light GL, blue light BL, or white light WL into a digital signal. In the present embodiment, the detector 990 uses a photo transistor or a photo diode.

The detector 990 periodically detects the amounts of the red light RL, the green light GL, the blue light BL, and the white light WL emitted to the first substrate 100 to control the detection signal. Output to (984). The detecting signal includes information related to the amount of light of the red light RL, the green light GL, the blue light BL, and the white light WL.

The control unit 984 compares the detecting signal of the detector 990 with a preset reference signal. The control unit 984 supplies power from the power supply 986 to the light source 982 when the light amount of the red light RL, the green light GL, the blue light BL, and the white light WL is lower than the designated light amount. Is applied to generate the second sensing light SL2 directed from the light source 982 to the liquid crystal display device 800. The second sensing light SL2 is emitted toward the light sensing element 270 of the liquid crystal display device 800.

As such, generating the second sensing light SL2 in response to the light amounts of the red light, the green light, the blue light, and the white light is generated by the light conversion unit 970 when the light amount of the red light, the green light, the blue light, and the white light is small. This is because the amount of light of the first sensing light SL1 is also small.

According to the present exemplary embodiment, when the amount of red light, green light, blue light and white light is insufficient and the amount of light of the first sensing light SL1 is insufficient, the second substrate from the inside of the body 960 of the light pen 950. The second sensing light SL2 is generated through the 200 toward the photosensitive device 170, so that the light pen 950 normally uses, for example, a vertical alignment mode liquid crystal. Black mode (normally black mode) It is possible to operate smoothly even in a liquid crystal display.

As described in detail above, the optical sensing element incorporated in the liquid crystal display device is formed under the transparent pattern to greatly improve the optical recognition rate of the photosensitive device, thereby preventing malfunction of the photosensitive device and improving display quality of the liquid crystal display device. Has the effect of greatly improving.

In the detailed description of the present invention described above with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (20)

A first pixel area in which a color filter is disposed to display a color image by emitting white, green, and blue light by filtering white light; a second pixel area that transmits the white light to improve brightness of the color image; A first substrate disposed in two pixel areas and including an optical sensing device for outputting a sensing signal by sensing light; A second substrate coupled to face the first substrate; A liquid crystal layer interposed between the first substrate and the second substrate; First electrodes disposed in the first and second pixel regions, respectively, to control the liquid crystal contained in the liquid crystal layer; And And a second electrode spaced apart from the first electrode to generate an electric field. The display device of claim 1, wherein a first thin film transistor including a first gate electrode, a first source electrode, and a first drain electrode is disposed under the color filter in the first and second pixel areas, respectively. And a gate electrode is connected to the first driving signal line, and the first source electrode is connected to the second driving signal line. The display device of claim 2, wherein the photosensitive device comprises: a first signal line disposed in parallel with the first driving signal line; A second transistor including a second gate electrode connected to the first signal line, a second source electrode connected to the second driving signal line, a second drain electrode, and a second channel layer to which the sensing light is incident; A second signal line arranged in parallel with the second driving signal line; And a third transistor including a third source electrode connected to the second drain electrode, a third gate electrode connected to the first driving signal line, a third drain electrode connected to the second signal line, and a channel layer. Device. The display device of claim 3, wherein the sensing light includes the red, green, blue, and white lights. The display device of claim 3, wherein a red color filter, a green color filter, and a blue color filter are disposed in the first pixel area of the color filter. The display device of claim 3, wherein a transparent pattern for transmitting the white light is disposed in the second pixel area of the color filter. The display device of claim 1, wherein the first pixel area and the second pixel area are arranged in a matrix form. The display device of claim 1, wherein the first electrode is disposed on the first substrate, and the second electrode is disposed on the second substrate. The display device of claim 8, wherein the liquid crystal is a twisted nematic liquid crystal. The method of claim 1, wherein the first and second electrodes are disposed on the first substrate, the first electrode is divided into a plurality, and the second electrode is interposed between the branched first electrodes. Display device characterized in that. The display device of claim 10, wherein the liquid crystal is a vertical alignment mode liquid crystal. The display device of claim 1, wherein the second electrode comprises a transparent and conductive indium tin oxide film or an indium zinc oxide film. The display device of claim 1, wherein the first electrode is a transparent and conductive indium tin oxide film or an indium zinc oxide film. The display device of claim 13, wherein the first electrode comprises a reflective electrode. The display device of claim 13, wherein the first electrode comprises a transparent electrode and a reflective electrode disposed on an upper surface of the transparent electrode. The display device of claim 15, wherein the reflective electrode has a plurality of transmission windows. A first pixel region in which a color filter for filtering white light and emitting red, green, and blue light to display a color image is disposed; a second pixel region for transmitting the white light to improve brightness of the color image; and the second pixel region; A first substrate disposed in the pixel region and including an optical sensing device for outputting a sensing signal by sensing light; A second substrate coupled to face the first substrate; A liquid crystal layer interposed between the first substrate and the second substrate; First electrodes disposed in the first and second pixel areas, respectively, to control the liquid crystal contained in the liquid crystal layer; A second electrode spaced apart from the first electrode to generate an electric field; And And a light pen including a light converter configured to convert the red, green, blue light and white light emitted from the first substrate into the sensing light. The display system of claim 17, wherein the light conversion unit comprises a light reflection unit for reflecting the red, green, blue light, and white light. The light pen of claim 17, wherein the light pen has a hollow body and is disposed inside the body to detect a light amount of the red, green, blue light, and white light to output a detecting signal when the light amount is less than a preset light amount. And a light source for outputting light to the photosensitive device by the detector and the detecting signal. 20. The display system of claim 19, wherein the light source is a light emitting diode.

Images