Flexible display device including a recognition pattern with different color concentration sub-patterns, and calibration method and display method thereof

A display device includes a flexible display panel including a recognition pattern, the recognition pattern having a plurality of sub-patterns with different color concentrations and disposed in a first direction, a housing accommodating the flexible display panel, the flexible display panel being configured to extend out of the housing in the first direction to vary a display area, and a photosensor in the housing, the photosensor corresponding to the recognition pattern and being configured to recognize the recognition pattern and to sense the display area of the flexible display panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 USC §119 to and the benefit of Korean Patent Application No. 10-2012-0054360, filed in the Korean Intellectual Property Office on May 22, 2012, the entire contents of which are incorporated herein by reference.

BACKGROUND

The described technology relates generally to a display device, a method for calibrating the display device, and a display method of the display device. More particularly, the described technology relates generally to a display device including a flexible display panel, a method for calibrating the display device, and a display method of the display device.

2. Description of the Related Art

A display device displays images, and a flexible display device has recently been paid much attention. The conventional flexible display device represents a device including a flexible display panel for displaying images, and the flexible display panel can be folded or rolled to reduce its size and allow portability.

SUMMARY

The described technology has been made in an effort to provide a display device for displaying an image optimized for a flexible characteristic of a flexible display panel, a method for calibrating the display device, and a display method of the display device.

An exemplary embodiment provides a display device including a flexible display panel including a recognition pattern, the recognition pattern having a plurality of sub-patterns with different color concentrations and disposed in a first direction, a housing accommodating the flexible display panel, the flexible display panel being configured to extend out of the housing in the first direction to vary a display area, and a photosensor in the housing, the photosensor corresponding to the recognition pattern and being configured to recognize the recognition pattern and to sense the display area of the flexible display panel.

The display device further includes a controller connected to the photosensor and the flexible display panel, and displaying an image corresponding to the display area of the flexible display panel sensed by the photosensor to the flexible display panel.

The controller includes a storage unit for storing values corresponding to respective display areas of the flexible display panel variably exposed in correspondence to the sub-patterns.

The flexible display panel further includes a display area for displaying the image and a non-display area neighboring the display area, and the recognition pattern is provided in the non-display area.

The recognition pattern is light reflective, and the photosensor includes a first light emitter and a first light receiver disposed to neighbor with each other.

The recognition pattern is light transmissive, and the photosensor includes a second light emitter and a second light receiver disposed to face each other with the recognition pattern therebetween.

The recognition pattern has an achromatic color or a chromatic color.

The sub-patterns have different chromatic colors, respectively.

The housing includes a rolled unit provided in the housing and on which the flexible display panel is wound.

The housing includes a darkroom surrounding the photosensor.

Another embodiment provides a method for calibrating a display device, including: providing the display device; recognizing a plurality of different sensor values sensed by the photosensor according to the sub-patterns; and storing a plurality of different area values corresponding to the respective display areas of the flexible display panel variable in correspondence to the different sensor values in the storage unit.

Another embodiment provides a display method of a display device, including: performing a method for calibrating the display device; allowing the photosensor to sense one of the sub-patterns to recognize the sensor value corresponding to the sub-pattern; loading the area value corresponding to the sensor value from the storage unit; and displaying an image corresponding to the display area of the flexible display panel corresponding to the area value to the flexible display panel.

DETAILED DESCRIPTION

In addition, the size and thickness of each component shown in the drawings may be arbitrarily shown for understanding and ease of description, but example embodiments are not limited thereto. For example, in the drawings, the thickness of layers, films, panels, regions, etc., may be exaggerated for clarity.

It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. Further, throughout the specification, “on” implies being positioned above or below a target element and does not imply being necessarily positioned on the top in accordance with a gravity direction. In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

A display device according to a first exemplary embodiment will now be described with reference toFIGS. 1-4.

FIG. 1shows a display device according to a first exemplary embodiment. As shown inFIG. 1, the display device includes a flexible display panel100, a housing200, a photosensor300, and a controller400.

The flexible display panel100displays an image processed by the display device. For example, when the display device is a mobile terminal, e.g., a cellular phone, the flexible display panel100may display an image related to the mobile terminal, e.g., a user interface (UI) or a graphics user interface (GUI) related to a call.

The flexible display panel100may include a flexible substrate or film with liquid crystal or an organic light emitting diode. The flexible display panel100may be formed to be transparent or light-transmissive, so that the outside may be viewed through the flexible display panel100. A touch sensor having a shape of a touch film, a touch sheet, or a touch pad, and sensing a touch operation, is provided on a front surface of the flexible display panel100. The flexible display panel100is connected to the controller400, and displays an image according to a signal transmitted by the controller400. The flexible display panel100exhibits flexible characteristics and is provided in the housing200. For example, the flexible display panel100may extend out of the housing in a first direction to variably expose a display area to the outside.

FIG. 2shows the flexible display panel100according to the first exemplary embodiment. In detail,FIG. 2(a) shows a rear surface (RS) of the flexible display panel100facing the photosensor300, andFIG. 2(b) shows a front surface of the flexible display panel100.

As shown inFIG. 2, the flexible display panel100includes a display area (DA) for displaying an image, a non-display area (NDA) neighboring the display area (DA), and a recognition pattern110provided in the non-display area (NDA). The display device includes the display area (DA) and the non-display area (NDA) on the rear surface (RS) of the flexible display panel100, but example embodiments are not restricted thereto, e.g., the display area (DA) may be provided on the rear surface (RS) of the flexible display panel100and the non-display area (NDA) may be provided on the front surface (FS) of the flexible display panel100. For example, when an image is displayed on the rear surface (RS) of the flexible display panel100, the recognition pattern110can be provided on either one of the front surface (FS) and the rear surface (RS) of the flexible display panel100.

Also, the recognition pattern110of the display device according to the first exemplary embodiment is provided in the non-display area (NDA), and the recognition pattern110of the display device according to another exemplary embodiment can be provided in the display area (DA) in which the image is displayed.

The recognition pattern110can be provided on one of the front surface or the rear surface of the flexible display panel100or between substrates of the flexible display panel100, and it can be formed when a wire or a touch sensor configuring the flexible display panel100is formed or it can be additionally formed on the surface of the flexible display panel100. The recognition pattern110is disposed in the first direction in which the flexible display panel100is provided into the housing200. The recognition pattern110is opto-reflective, and it includes a plurality of sub-patterns (110a-110j) that are disposed in the first direction. The sub-patterns (110a-110j) have different color concentrations in the first direction. In detail, the sub-patterns (110a-110j) have an achromatic color or a chromatic color.

For example, when the sub-patterns (110a-110j) have an achromatic color, each of the sub-patterns (110a-110j) may have different color concentrations, so the color concentration gradually increases from a first sub-pattern110aat a first end to a last sub-pattern110jat a second end to have colors from black to white or from white to black. In another example, when the sub-patterns (110a-110j) have a chromatic color, e.g., red, green, yellow, or blue, the sub-patterns (110a-110j) gradually have different color concentrations from the first sub-pattern110aat the first end to the last sub-pattern110jat the second end to have colors from the dark chromatic color to the light chromatic color or from the light chromatic color to the dark chromatic color.

Referring back toFIG. 1, the housing200supports a first end of the flexible display panel10and receives the flexible display panel100thereinside, so that the display area of the flexible display panel100may be variably exposed, i.e., a size of the display area may be changed, e.g., varied, in accordance with a length of the flexible display panel100pulled out of the housing200. That is, the housing200includes a rolled unit210on which the flexible display panel100is wound. The rolled unit210is provided inside the housing200and supports the first end of the flexible display panel100. The rolled unit210winds the flexible display panel100so that the flexible display panel100may be provided in a first direction with respect to the housing200. The rolled unit210is rotatable, e.g., passively or actively, and when the rolled unit210is rotated, the flexible display panel100may be pulled out to unwind and extend in the first direction with respect to the housing200.

In addition, the housing200includes a darkroom220surrounding the photosensor300. That is, the photosensor300is provided inside the darkroom220, so unexpected external light is not irradiated onto the photosensor300. Accordingly, a sensing error by the photosensor300, e.g., potentially caused by external light, may be prevented or substantially minimized, thereby improving sensing reliability of the photosensor300.

FIG. 3shows a method for sensing a display device according to a first exemplary embodiment.

As shown inFIG. 3, the photosensor300is provided in correspondence to the recognition pattern110in the non-display area (NDA) of the flexible display panel100. For example, the photosensor300may be positioned to overlap the recognition pattern110. The photosensor300recognizes the recognition pattern110to sense the display area of the flexible display panel100exposed to the outside of the housing200.

As shown inFIG. 3, the photosensor300includes a first light emitter310and a first light receiver320that are adjacent each other. The first light emitter310emits light in a direction of the recognition pattern110, and the first light receiver320receives the light emitted by the first light emitter310and reflected by the recognition pattern110.

The photosensor300uses the first light emitter310and the first light receiver320to sense the recognition pattern110, thereby sensing the display area (DA) of the flexible display panel100exposed to the outside of the housing200. In detail, when the flexible display panel100extends out of the housing200in the first direction, light emitted by the first light emitter310toward the extended flexible display panel100, i.e., toward the recognition pattern110, is incident on and reflected by the recognition pattern110to be received by the first light receiver320. Therefore, the first light receiver320detects intensity of the received light. The light received by the first light receiver320is converted into a corresponding voltage value in a circuital manner, and the voltage value is changed into a digital value to be recognized.

For example, if the sub-pattern110aat the first end from among the sub-patterns (110a-110j) has a pure black color, the sub-pattern110aabsorbs the entire light emitted from the first light emitter310, i.e., no light is reflected back toward the first light receiver320. Accordingly, the first light receiver320receives no light, and the photosensor300registers voltage of 0 V in a circuital manner. In another example, if the sub-pattern110jat the second end from among the sub-patterns (110a-110j) has a pure white color, the sub-pattern110jreflects the entire light emitted by the first light emitter310, i.e., the first light receiver320receives the entire light emitted by the first light emitter310. Accordingly, the photosensor300registers maximum voltage value, e.g., 3.0 V, in a circuital manner. In yet another example, if the color concentration of the achromatic color of the sub-pattern110damong the sub-patterns (110a-110j) is about 70%, about 30% of light is reflected toward the first light receiver320. As the voltage range between the sub-patterns110aand110jis between 0 V and 3.0 V, respectively, the photosensor300registers voltage of about 0.9 V with respect to the sub-pattern110d.

That is, the photosensor300does not recognize the recognition pattern110as black and white, but it recognizes different reflected amounts of light from the sub-patterns (110a-110j) that have different color concentrations and are arranged in the first direction. The photosensor300senses the display area of the flexible display panel100that is exposed when the reflected amount of light by one sub-pattern from among the sub-patterns (110a-110j) is recognized.

When an operational range of the first light receiver320of the photosensor300is from about 0 V to about 3.0 V, as described in the above example s, and there are ten sub-patterns (110a-110j), it is possible to manufacture each sub-pattern to have about 0.3 V by controlling the color concentrations of the plurality of sub-patterns (110a-110j). When the sensing performance of the first light receiver320is about 0.1 V and the operational range of the first light receiver320is about 0 V to about 3.0 V, the number of configurable sub-patterns can be set to be 30. Without being restricted to the above, the number of sub-patterns can be set to as many as needed by setting the voltage value of the recognition sensing performance of the first light receiver320and setting the voltage value of the operational range of the first light receiver320.

The photosensor300senses the display area (DA) that is variably exposed, i.e., corresponding to the sub-patterns (110a-110j), when the flexible display panel100is provided in the first direction of the housing200. A signal on the exposed display area (DA) of the flexible display panel100sensed by the photosensor300is transmitted to the controller400.

FIG. 4shows an image displayed by the flexible display panel100of the display device according to the first exemplary embodiment.

As shown inFIG. 4, the controller400is connected to the photosensor300and the flexible display panel100, and it displays the image corresponding to the exposed display area of the flexible display panel100sensed by the photosensor300to the flexible display panel100. The controller400includes a storage unit410for storing values that correspond to the display area of the flexible display panel100that is variably exposed in correspondence to the sub-patterns (110a-110j). The storage unit410can be a volatile or non-volatile storage medium.

In detail, as shown inFIG. 4(a), when the flexible display panel100is provided into the housing200in the first direction for the first time, and a first display area DA1is exposed, the photosensor300recognizes the sub-pattern when the first display area DA1is exposed from among the sub-patterns (110a-110j), it senses the first display area DA1and transmits a signal on the first display area DA1to the controller400, and the controller400receives the signal and displays an image of a first size corresponding to the first display area DA1of the flexible display panel100. In this instance, the controller400stores a value that corresponds to the first display area DA1of the flexible display panel100that is exposed corresponding to the sub-pattern when the first display area DA1is exposed in the storage unit410, or it loads a value that is stored in the storage unit410.

Further, as shown inFIG. 4(b), when the flexible display panel100is provided in the housing200in the first direction for a second time and a second display area DA2that is greater than the first display area DA1is exposed, the photosensor300recognizes the sub-pattern from among the sub-patterns (110a-110j) when the second display area DA2is exposed, it senses the second display area DA2to transmit a signal on the second display area DA2to the controller400, and the controller400receives the signal and displays an image of a second size corresponding to the second display area DA2of the flexible display panel100. In this instance, the controller400stores the value that corresponds to the second display area DA2of the flexible display panel100exposed corresponding to the sub-pattern when the second display area DA2is exposed in the storage unit410or it loads the value stored in the storage unit410.

Also, as shown inFIG. 4(c), when the flexible display panel100is provided in the housing200in the first direction for a third time and a third display area DA3that is greater than the second display area DA2is exposed, the photosensor300recognizes the sub-pattern when the third display area DA3is exposed from among the sub-patterns (110a-110j), it senses the third display area DA3to transmit a signal on the third display area DA3to the controller400, and the controller400receives the signal and displays an image of a third size that corresponds to the third display area DA3of the flexible display panel100. In this instance, the controller400stores the value that corresponds to the third display area DA3of the flexible display panel100exposed corresponding to the sub-pattern when the third display area DA3is exposed in the storage unit410or it loads the value stored in the storage unit410.

Particularly, when the flexible display panel100is provided in the housing200in the first direction, the photosensor300does not recognize an order of the sub-patterns (110a-110j) formed on the flexible display panel100, but rather senses the exposed display area of the flexible display panel100corresponding to the sensed sub-patterns (110a-110j) on the exposed display area. For example, if the sub-patterns (110a-110j) extend in the first direction along an entire length of the display areas DA in the first direction, the photosensor300may sense the sub-patterns on an exposed display area, e.g., the photosensor300may detect the specific sub-pattern directly below in order to determine the sub-patterns on the exposed display area extending sequentially from the detected specific sub-pattern along the first direction, to determine a size of a desired image to be displayed. Therefore, when power is supplied to the display device under any condition, the display device recognizes the sub-patterns that correspond to the currently exposed display area without monitoring the process for providing the flexible display panel100in the housing200and displays the image of a size that corresponds to the exposed display area.

As described, the photosensor300recognizes the recognition pattern110formed on the flexible display panel100in order to sense a size of a display area of the flexible display panel100that is exposed to the outside, i.e., pulled out of the housing200. Once the size of the exposed displayed area is determined, an image that corresponds to the determined size of the display area may be displayed on the flexible display panel100. Therefore, the image for the display device may be optimized for the flexible characteristic of the flexible display panel100.

Particularly, the display device according to the first exemplary embodiment uses the photosensor300in the housing200to recognize the recognition pattern110formed on the flexible display panel100and to sense the display area of the externally exposed flexible display panel100provided in the housing200. Therefore, when the exposed surface of the flexible display panel100is drawn from the housing200and is then bent nonlinearly, the photosensor300can accurately sense the display area of the flexible display panel100that is output from the housing200and is exposed to the outside.

That is, the display device according to the first exemplary embodiment does not sense the entire area of the flexible display panel100when it is discharged from the housing200. The photosensor300recognizes in real-time the recognition pattern110of the flexible display panel100and senses the display area of the flexible display panel100. Therefore, when the exposed surface of the flexible display panel100is nonlinearly bent, it can display the image of a size corresponding to the exposed display area by sensing the display area of the externally exposed flexible display panel100.

Further, the display device according to the first exemplary embodiment does not count revolutions of the rolled unit210to indirectly sense the display area of the flexible display panel100and does not use a distance measuring means, e.g., infrared rays or ultrasonic waves, to sense the display area of the unfolded flexible display panel100. Instead, the display device recognizes in real-time the recognition pattern110exposed on the exposed display area of the flexible display panel100, so an image with an accurate size corresponds to the variable display area of the flexible display panel100may be variably displayed on the flexible display panel100, which functions as a factor for improving the user's satisfaction with the display device.

Also, when the flexible display panel100is provided in the housing200in the first direction, the photosensor300does not recognize the order of all the sub-patterns (110a-110j) formed on the flexible display panel100, but the photosensor300senses the display areas of the flexible display panel100corresponding to the exposed sub-patterns (110a-110j) to directly sense the exposed display area of the flexible display panel100. Therefore, when power is supplied to the display device under any conditions, the display device recognizes the sub-pattern corresponding to the currently exposed display area without monitoring the process for providing the flexible display panel100in the housing200and displays the image of the size corresponding to the exposed display area. That is, regarding the display device according to the first exemplary embodiment, the photosensor300independently identifies and recognizes the sub-pattern (110a-110j) with different color concentrations and displays the image of the size corresponding to the exposed display area without an additional configuration when the power is suddenly turned off or when the flexible display panel100is unfolded and a part of it is folded.

A method for calibrating a display device according to a second exemplary embodiment will now be described with reference toFIG. 5. The method for calibrating a display device according to the second exemplary embodiment will be performed by using the display device according to the first exemplary embodiment.

FIG. 5shows a flowchart for calibrating a display device according to a second exemplary embodiment.

As shown inFIG. 5, a plurality of different sensor values sensed by the photosensor300are sensed (S110). In detail, when the flexible display panel100is provided in the housing200in the first direction, an amount of light (i.e., a voltage value) sensed by the photosensor300according to the sub-patterns (110a-110j) is extracted to sense different sensor values.

A plurality of different area values are stored in the storage unit410corresponding to the different sensor values (S120). In detail, the different sensor values corresponding to the sub-patterns (110a-110j) are matched with different area values corresponding to the display areas of the variably exposed flexible display panel100, and the area values are stored in the storage unit410. For example, when the number of the sub-patterns (110a-110j) is ten, the size of the different display areas of the flexible display panel100is ten.

That is, the first sub-pattern is recognized to match the sensor value and the first area value that corresponds to a predetermined display area, and so forth, until the sensor value having recognized the tenth sub-pattern is matched with the ten sub-patterns and the area value, i.e., corresponding to the ten area values corresponding to the ten display areas corresponding to ten sub-patterns are stored in the storage unit410. When the rolled unit210of the housing200is driven by a motor, the above-noted calibration method can be automatically performed by rotation of the rolled unit210caused by rotation of the motor.

A display method of a display device according to a third exemplary embodiment will now be described with reference toFIG. 6. The display method of a display device according to the third exemplary embodiment can be performed by using the display device according to the first exemplary embodiment.

FIG. 6shows a flowchart for a display method of a display device according to the third exemplary embodiment.

As shown inFIG. 6, a method for calibrating the display device according to the second exemplary embodiment is performed (S210).

The photosensor300senses one of the sub-patterns (110a-110j) to recognize the sensor value corresponding to the sub-pattern (S220).

The area value corresponding to the sensor value is loaded from the storage unit410(S230).

An image corresponding to the display area of the flexible display panel100corresponding to the area value from operation (S230) is displayed to the flexible display panel100(S240).

In detail, when the flexible display panel100is provided in the housing200in the first direction after the method for calibrating the display device is performed, the photosensor300senses the sub-patterns (110a-110j) to recognize the respective sensing values, and area values corresponding to the sensing values are loaded from the storage unit410so the image corresponding to the display area of the flexible display panel100corresponding to the area value is displayed to the flexible display panel100.

A display device according to a fourth exemplary embodiment will now be described with reference toFIG. 7andFIG. 8.

FIG. 7shows a display device according to a fourth exemplary embodiment.FIG. 8shows a flexible display panel of a display device according to a fourth exemplary embodiment.FIG. 8(a) shows a rear surface (RS) of a flexible display panel104facing a photosensor304, andFIG. 8(b) shows a front surface (FS) of the flexible display panel104.

As shown inFIG. 7andFIG. 8, the display area (DA) and the non-display area (NDA) of a display device according to the fourth exemplary embodiment are provided on the rear surface (RS) and the front surface (FS) of the flexible display panel104.

The recognition pattern114is light transmissive, and includes a plurality of sub-patterns (114a-114j) disposed in the first direction. The sub-patterns (114a-114j) have different color concentrations in the first direction. In detail, the sub-patterns (114a-114j) have an achromatic color or a chromatic color, and when the sub-patterns (114a-114j) have an achromatic color, the sub-patterns (114a-114j) from the sub-pattern114aat a first end to the sub-pattern114jat a second end from among the sub-patterns (114a-114j) gradually have different color concentrations and thereby have colors from black to white or from white to black.

Further, when the sub-patterns (114a-114j) have a chromatic color such as red, green, yellow, or blue, the sub-patterns (114a-114j) gradually have different color concentrations from the sub-pattern114aat the first end to the sub-pattern114jat the second end from among the sub-patterns (114a-114j) from among the sub-patterns (114a-114j) thereby having colors from the dark chromatic color to the bright chromatic color or from the bright chromatic color to the dark chromatic color.

A photosensor304is provided in the darkroom220of the housing200. The photosensor304includes a second light emitter330and a second light receiver340that are disposed to face each other with the recognition pattern114therebetween. The second light emitter330emits light in the direction of the recognition pattern114, and the second light receiver340receives the light that is emitted by the first light emitter310and transmitted through the recognition pattern114.

The photosensor304uses the second light emitter330and the second light receiver340to recognize the recognition pattern114, and senses the display area of the flexible display panel104provided in the housing200and exposed to the outside. In detail, when the flexible display panel104is provided in the housing200in the first direction, the light emitted by the second light emitter330is transmitted through the recognition pattern114and is received by the second light receiver340so the second light receiver340detects intensity of the received light. The light received by the second light receiver340is converted into a corresponding voltage value in a circuital manner, and the voltage value is changed into a digital value to be recognized.

For example, if the sub-pattern114aat the first end from among the sub-patterns (114a-114j) has a pure black color, the sub-pattern114aabsorbs the entire light emitted from the second light emitter330. Therefore, when the second light receiver340receives no light, the photosensor304recognizes voltage about 0 V in a circuital manner. Also, if the sub-pattern114jat the second end from among the sub-patterns (114a-114j) is theoretically transparent, e.g., completely transparent, the transparent sub-pattern114jat the second end transmits the entire light emitted by the second light emitter330to the second light receiver340. Therefore, the photosensor304recognizes about 3.0 V in a circuital manner, when the sensor maximum limit value of the second light receiver340is 3.0 V. Therefore, when a voltage range of the recognition pattern114is about 0 V to about 3.0 V, the gradual increase or decrease of color concentration, e.g., achromatic color, of one sub-pattern114dfrom among the sub-patterns (114a-114j) is substantially 70% and 30% of light is transmitted, the second light receiver340receives the 30% of the light and the photosensor304recognizes voltage of about 0.9 V.

As described, regarding the display device according to the fourth exemplary embodiment, the photosensor304recognizes the recognition pattern114formed on the flexible display panel104to sense the display area of the flexible display panel104provided in the housing200and exposed to the outside. The image corresponding to the display area is displayed to the flexible display panel104, so the display device for displaying the image optimized for the flexible characteristic of the flexible display panel104is provided.

A display device according to a fifth exemplary embodiment will now be described with reference toFIG. 9.FIG. 9shows a flexible display panel of a display device according to the fifth exemplary embodiment.FIG. 9(a) shows a rear surface (RS) of a flexible display panel105facing the photosensor300, andFIG. 8(b) shows a front surface (FS) of the flexible display panel105.

As shown inFIG. 9, a recognition pattern115of the display device according to the fifth exemplary embodiment is light transmissive, and includes a plurality of sub-patterns (115a-115j) disposed in the first direction. The sub-patterns (115a-115j) have different color concentrations in the first direction and different chromatic colors. In detail, the sub-patterns (115a-115j) have different chromatic colors, and the sub-patterns (115a-115j) from the sub-pattern115aat a first end to the sub-pattern115jat a second end from among the sub-patterns (115a-115j) have different chromatic colors with different color concentrations. For example, the sub-patterns (115a-115j) can have one of red, orange, yellow, green, blue, and violet colors, and can also have other colors.

The photosensor300represents a color photosensor including a third light emitter and a third light receiver facing each other with the recognition pattern115therebetween and recognizing a chromatic color.

The photosensor300uses the third light emitter and the third light receiver to recognize the recognition pattern115and sense the display area of the flexible display panel105provided in the housing200and exposed to the outside. In detail, when the flexible display panel105is provided in the housing200in the first direction, the light emitted by the third light emitter is transmitted through the recognition pattern115, and the third light receiver receives the light the color of which is changed by the recognition pattern115and detects the color of the received light. The color of the light received by the third light receiver is changed into a corresponding voltage value in a circuital manner, it is changed into a digital value, and it is then recognized.

Accordingly, regarding the display device according to the fifth exemplary embodiment, the photosensor300recognizes the recognition pattern115formed on the flexible display panel105to sense the display area of the flexible display panel105provided in the housing200and exposed to the outside, and the image corresponding to the display area is displayed to the flexible display panel104. Therefore, the display device displays am optimized image for the flexible characteristic of the flexible display panel105.