DISPLAY APPARATUS FOR USE IN VEHICLE AND CONTROL METHOD THEREFOR

A display device including, a display panel including a plurality of pixels on a front surface; a housing including a housing opening through which the display panel enters or exits; a first sensor unit configured to sense a temperature of the display panel; a second sensor unit configured to sense an internal temperature of the housing; a pixel sensing unit configured to sense an active area in which the plurality of pixels are in an active state and an inactive area in which the plurality of pixels are in an inactive state; a functional status calculation unit configured to calculate a functional status of each of the plurality of pixels on the basis of information received from the first sensor unit, the second sensor unit, and the pixel sensing unit; a weight calculation unit configured to calculate a function weight on the basis of functional status of each of the plurality of pixels and calibrate a lifespan of each of the plurality of pixels on the basis of the calculated function weight; and a pixel calibration unit configured to calibrate luminance of the plurality of pixels and calibrate color between the plurality of pixels.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Patent Applications No. 10-2023-0054298, filed on Apr. 25, 2023 in Korea, and No. 10-2023-0063114, filed on Apr. 16, 2023 in Korea the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a display device and control method.

BACKGROUND

The content described in this section simply provides background information for the present disclosure and does not constitute related art.

A display may be configured using an organic light emitting diode (OLED). The OLED has a panel issue called burn-in phenomenon. Here, the burn-in phenomenon occurs when some pixels on a display panel continuously display the same image. Brightness of each pixel in the OLED decreases when an image is continuously displayed. Therefore, in the related art, luminance of the display panel is adjusted and a lifespan of the display panel is managed on the basis of a temperature of the display panel and a driving ratio of the pixels. Here, the driving ratio refers to a ratio of areas divided according to an active state of pixels on the display panel or an inactive state of the pixels on the display panel.

In a rollable display and/or a slidable display, a size of a screen on which a display panel is exposed is adjusted when the display is used. When the size of the screen on which the display panel is exposed is adjusted, a partial area of the display panel is rolled down in a housing. The rolled-down area of the display panel has residual heat that has been generated at the time of exposure even though pixels are not driven. The rolled-down area of the display panel changes an internal temperature of the housing. In the rolled-down area, heat is not effectively dissipated as the internal temperature of the housing increases. Therefore, burn-in may rapidly occur in the rolled-down area. Further, in the rolled-down area, a border area adjacent to the exposed area on the display panel requires accurate lifespan management because the border area is affected by a temperature of the exposed area.

A flexible display has a problem that the flexible display is easily damaged by an external force. The flexible display is exposed to a user by being unrolled or slid from inside of a housing. For example, when there is an object within an exposure range of the flexible display, the flexible display may be damaged due to contact with the object while moving.

When the flexible display malfunctions, it is difficult to determine whether the malfunction is due to an internal defect of the display device or due to an external force transferred from the outside of the display device.

SUMMARY

A display device and a control method according to an embodiment can manage lifespans of the plurality of pixels by sensing a temperature at each position on a display panel.

A display device and a control method according to an embodiment can calibrate luminance and color of a display panel on the basis of a position value of an inactive area and a temperature of the inactive area on the display panel.

A display device and a control method according to an embodiment can calibrate luminance and color of a display panel on the basis of an internal temperature of a housing.

A display device and a control method according to an embodiment can calibrate a lifespan of a display panel on the basis of an area with a largest function decline on the display panel or one pixel with a largest function decline among a plurality of pixels on the display panel.

A display device according to another embodiment can determine whether there is an internal defect of a display panel or an external force and send a corresponding warning message to a user.

A display device according to another embodiment can protect a display panel from a damage risk and maintain repairability.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to an embodiment, the display device and the control method have an effect that it is possible to manage lifespans of the plurality of pixels by sensing a temperature at each position on a display panel.

According to an embodiment, the display device and the control method have an effect that it is possible to calibrate luminance and color of a display panel on the basis of a position value of an inactive area and a temperature of the inactive area on the display panel.

According to an embodiment, the display device and the control method have an effect that it is possible to calibrate luminance and color of a display panel on the basis of an internal temperature of a housing.

According to an embodiment, the display device and the control method have an effect that it is possible to calibrate a lifespan of a display panel on the basis of an area with a largest function decline on the display panel or one pixel with a largest function decline among a plurality of pixels on the display panel.

According to another embodiment, the display device has an effect that it is possible to determine whether there is an internal defect of a display panel or an external force and send a corresponding warning message to a user.

According to another embodiment, the display device has an effect that it is possible to protect a display panel from a damage risk and maintain repairability.

DETAILED DESCRIPTION

FIG.1is a perspective view illustrating a display device according to an embodiment of the present invention.

FIG.2is a block configuration diagram illustrating a configuration of the display device according to the embodiment of the present invention.

FIG.3is a cross-sectional view taken along line A-A ofFIG.1.

FIG.4is a diagram illustrating an example of driving according to an active state and an inactive state of the display panel.

Referring toFIGS.1to4, a display device100includes some or all of a display panel110, a housing120, a first sensor unit220, a second sensor unit230, and a display control unit240.

The housing120includes a housing opening310through which the display panel110enters or exits. The housing opening310is open in a z-axis direction with a top surface of the housing120as a reference.

The display panel110may cause only pixels in a portion exposed to the outside of the housing120to emit light. Here, the exposed portion of the display panel110provides a display image to a user. A non-exposed portion of the display panel110enters the housing120through a scheme such as rolling. The display panel110includes a plurality of pixels (not illustrated). Each of the plurality of pixels operates independently.

There may be a plurality of first sensor units220. The first sensor unit220may be disposed on both sides of the display panel110. The first sensor unit220may be a temperature sensor that measures a front surface temperature of an inactive area412on the display panel110. Accordingly, after the display panel110enters the housing120, the first sensor unit220measures a temperature of the inactive area412on the display panel110, that is, an area of pixels that does not emit light. The first sensor unit220may be disposed adjacent to the housing opening310. Specifically, the first sensor unit220may be disposed adjacent to the housing opening310to measure a temperature of a front surface of the inactive area412on the display panel110entering the housing120, in an active area410on the display panel110, that is, in an area in which a display is being performed.

The second sensor unit230may be a temperature sensor that measures an internal temperature of the housing120. Here, the internal temperature is a temperature of the air inside the housing120. The second sensor unit230may be disposed at any one place inside the housing120. InFIG.3, the second sensor unit230is shown as being disposed on a rear side of the housing120, but is not limited thereto. A position of the second sensor unit230is preferably disposed at a predetermined distance away from the display panel110not to be affected by a temperature of the active area410on the display panel110.

The second sensor unit230may include a plurality of temperature sensors. The second sensor unit230may be disposed at a plurality of positions inside the housing120to measure an internal temperature of the housing120. The display control unit240may estimate an average internal temperature value of the housing120using the second sensor unit230.

When the active area410of the display panel110is, for example, 100%, the display panel110is in a full screen mode. When the display panel110is in the full screen mode, all pixels on the display panel110are in the active state. When the active area410of the display panel110is changed from 100% to 70%, for example, 30% of the display panel110becomes the inactive area412. Here, the inactive area412enters the housing120. After the inactive area412enters the housing120, the internal temperature of the housing120increases because of residual heat generated in the active state. Accordingly, the first sensor unit220is preferably disposed at a position at which a transition from the active area410to the inactive area412on the display panel110occurs.

The display control unit240includes some or all of a functional status calculation unit241, a weight calculation unit242, and a pixel calibration unit243, which. individually or together, may be implemented by a processor.

The display control unit240may receive the front surface temperature value of the display panel110from the first sensor unit220. The display control unit240may receive the internal temperature value of the housing120from the second sensor unit230.

The display control unit240may determine lifespans of the plurality of pixels on the basis of display information received from the first sensor unit220and the second sensor unit230. Here, the display information includes pixel position information, first temperature information, and second temperature information. The position information of the pixel includes a position value of the inactive area412. The first temperature information includes a temperature value of the inactive area412in the plurality of pixels. The second temperature information includes the internal temperature value of the housing120.

The display control unit240may calculate the lifespans of the plurality of pixels and then calibrate the lifespans of all pixels formed on the display panel110on the basis of the lifespan of at least one pixel with a shortest lifespan among the plurality of pixels. The display control unit240may calibrate the lifespans of all the pixels formed on the display panel110on the basis of a lifespan of an area with a shortest lifespan on the display panel110.

A pixel sensing unit210, implemented by, for example, a circuit, may sense an active sate and an inactive state of each of the plurality of pixels. In other words, the pixel sensing unit210may distinguish between the active area410and the inactive area412on the display panel110. The pixel sensing unit210may sense a position value of an area on the display panel110entering or exiting the housing opening310. For example, the pixel sensing unit210may measure a current supplied to each pixel and determine whether each pixel is active or inactive on the basis of a current value. Accordingly, the pixel sensing unit210may estimate the position value of the pixel in the active state or the pixel in the inactive state among the plurality of pixels.

The functional status calculation unit241may calculate a functional status of each of the plurality of pixels on the basis of the display information received from the pixel sensing unit210, the first sensor unit220, and the second sensor unit230.

The weight calculation unit242may assign a function weight to the inactive area412on the display using at least one of pixel position information, first temperature information, and second temperature information. Here, the function weight is a weight for the lifespans of the plurality of pixels.

The weight calculation unit242may distinguish the function weight between the plurality of pixels or assign the function weight to each pixel. For example, the weight calculation unit242may assign a function weight in proportion to a distance of the inactive areas412adjacent to the active area410. For example, a temperature of the active area410on the display panel110is higher than that of the inactive area412on the display panel110because the plurality of pixels emit heat. Accordingly, an area of the inactive area412on the display panel110close to the active area410is affected by the heat emitted from the active area410. Accordingly, the weight calculation unit242may assign a larger function weight to the area of the inactive area412close to the active area410.

The weight calculation unit242may assign a function weight to the inactive area412of the plurality of pixels on the basis of the first temperature information. This is because, as the first temperature information is higher, the temperature of the inactive area412whose temperature is measured by the first sensor unit220is higher.

The weight calculation unit242may assign a function weight proportional to the second temperature information to the inactive area412, in which the temperature is measured by the first sensor unit220. For example, this is because, as the internal temperature of the housing120increases, the temperature of the inactive area412on the display panel110increases. When the temperature of the inactive area412increases, the lifespan of the pixel disposed in the inactive area412may decrease.

The pixel calibration unit243may calibrate luminance of the plurality of pixels with one pixel with a largest function decline among the plurality of pixels or an area with a largest function decline on the display panel110as a reference on the basis of the lifespans of the plurality of pixels calculated by the functional status calculation unit241. The pixel calibration unit243may calibrate colors of the plurality of pixels.

When the pixel calibration unit243calibrates the luminance of the entire display panel110, the pixel calibration unit243may remove an afterimage of the inactive area412of the plurality of pixels and calibrate life uniformity of the display panel110.

FIG.5is a flowchart illustrating a control method for a display device according to an embodiment of the present invention.

Referring toFIG.5, the pixel sensing unit210senses an operation time of each of the plurality of pixels on the display panel110(S510).

After a portion of the display panel110enters the housing120, the pixel sensing unit210senses an operation time of the inactive area412of the plurality of pixels (S520). The pixel sensing unit210may measure the position values of the active area410and the inactive area412of the plurality of pixels on the display panel110and sense the operation time.

Display information of the inactive area412of the plurality of pixels is sensed (S530). The display control unit240may receive the display information of the inactive area412. The display control unit240may receive the display information from the pixel sensing unit210, the first sensor unit220, and the second sensor unit230.

The functional status of the inactive area412is determined on the basis of the display information (S540). The functional status calculation unit241may calculate the functional status of the inactive area412.

A function weight is assigned to the inactive area412on the basis of the functional status of the plurality of pixels (S550). The weight calculation unit242assigns a function weight on the basis of the functional status of the inactive area412.

After the function weights are assigned to the plurality of pixels, the lifespan of the inactive area412is calculated (S560). After the function weights are assigned to the plurality of pixels, the display control unit240may calculate the lifespan of the inactive area412.

The luminance and color of the plurality of pixels are calibrated (S570). When the pixel calibration unit243calibrates the luminance and color of the plurality of pixels, the pixel calibration unit243calibrates the luminance and color of the plurality of pixels on the basis of the pixel with a largest lifespan decline among the plurality of pixels or an area with a largest lifespan decline on the display panel110.

FIG.6is a perspective view illustrating a configuration of a display device according to another embodiment of the present invention.

FIG.7is a partially enlarged view illustrating the third sensor unit, the fourth sensor unit, and the fifth sensor unit in detail according to another embodiment of the present disclosure.

Referring toFIGS.6and7, the display device600includes some or all of a display panel610, a housing612, third sensor units621and622, a fourth sensor unit623, and a fifth sensor unit630.

The display panel610may include a rollable display or a slidable display. The display panel610is rolled around a cylindrical member625disposed inside the housing612. The cylindrical member625rotates on the basis of a rotational force of a motor127. The motor127generates the rotational force to rotate the cylindrical member625, and the cylindrical member625rotates so that the display panel610can move. Here, the movement includes horizontal or vertical movement and rolling or unrolling operations. The rolling operation is an operation in which the display panel610is rolled around the cylindrical member625and is moved into the housing612. The unrolling operation is an operation in which the display panel610moves to the outside of the housing612. A guide member626may be disposed near the cylindrical member625. The guide member626may move the display panel610without interference with the display panel610when the display panel610is rolled or when the display panel610is exposed to the outside of the housing612.

The third sensor units621and622are disposed on a rear surface of the display panel610. The third sensor units621and622include a third sensor621and a fourth sensor622. The third sensor621and the fourth sensor622may be photo sensors.

The third sensor621and the fourth sensor622may be disposed at the same height on the rear surface of the display panel610. The third sensor621is disposed on one side of the display panel610, and the fourth sensor622is disposed on the other side of the display panel610. The third sensor621and the fourth sensor622may sense a plurality of grooves700formed on the rear surface of the display panel610. Here, the plurality of grooves700are formed at regular intervals with a movement direction of the display panel610as a reference. When the display panel610moves, the third sensor621and the fourth sensor622may measure some or all of the plurality of grooves700. Accordingly, the third sensor621and the fourth sensor622may obtain information on the movement direction and current position of the display panel610.

For the third sensor units621and622according to another embodiment of the present invention, hall sensors may be used. The display panel610according to another embodiment of the present invention may include a plurality of magnets disposed at regular intervals on the rear side in the movement direction of the display panel610. The hall sensor may measure the number of magnets and the movement directions of the magnets.

The fourth sensor unit623measures a rotation value of the cylindrical member625. The fourth sensor unit623is disposed adjacent to the cylindrical member625. Specifically, a slot disk624is coupled to one side of the cylindrical member625. The slot disk624includes slots formed at regular intervals on an outer peripheral surface. When the slot disk624rotates, the fourth sensor unit623may measure the rotation value of the cylindrical member625by counting the slots. The fourth sensor unit623may be a photo interrupter.

The fifth sensor unit630is disposed at an upper end of the display panel610. The fifth sensor unit630may be a proximity sensor module. The fifth sensor unit630may determine the presence or absence of an object at the top of the display panel610. The fifth sensor unit630may determine the presence or absence of an external force at the top of the display panel610. For example, when the display panel610moves and is exposed and an object is within an exposure range of the display panel610, the display panel610may be damaged. Accordingly, the fifth sensor unit630may determine the presence or absence of an object or external force within the exposure range of the display panel610.

The display device600further includes a control unit (not illustrated). The control unit may be disposed on the PCB628inside the display device600. The control unit may be an electronic control unit. The control unit may determine whether or not the balance of the display panel610is maintained on the basis of information on the movement direction of the display panel610and the current position of the display panel610measured by the third sensor621and the fourth sensor622. For example, the control unit may determine whether or not the balance of the display panel610is maintained by comparing the number of grooves measured by the third sensor621and the fourth sensor622. When the number of grooves measured by the third sensor621and the fourth sensor622are different, the control unit may determine that the balance of the display panel610is not maintained.

The control unit may compare the movement value of the display panel610measured by the third sensor units621and622with the rotation value of the cylindrical member625measured by the fourth sensor unit623. This is because the movement value of the display panel610is the same as the rotation value of the cylindrical member625. Accordingly, the control unit may determine whether the display panel610is malfunctioning using the third sensor units621and622and the fourth sensor unit623.

FIG.8is a flowchart illustrating a display control method according to another embodiment of the present disclosure.

The display panel610is operated by being unrolled to the outside of the housing612or rolled into the housing612(S800). The display panel610may be exposed to the outside of the housing612. In the display device600according to an embodiment of the present invention, the display panel610may be rolled and exposed to the outside of the housing612. Here, the display panel610may be exposed upward with the upper case611as a reference.

The current position and the balance of the display panel610are sensed (S810). When the display panel610moves, the third sensor units621and622may use the third sensor621and the fourth sensor622to sense the current position of the display panel610and the balance of the display panel610. Here, the current position of the display panel610means moving toward the outside of the housing612(rolling out) or moving toward the inside of the housing612(rolling in). The third sensor621and the fourth sensor622may sense the balance of the display panel610by sensing the plurality of grooves700formed on the rear side of the display panel610. The fourth sensor unit623may measure a rotation value of the slot disk624.

A determination is made as to whether there is an error in an operation of the display panel610(S820). The control unit may determine whether there is an error in the operation of the display panel610on the basis of the movement value of the display panel610and the rotation value of the slot disk624. For example, when the movement values of the display panel610measured by the third sensor621and the fourth sensor622are different from each other, a determination may be made that the display panel610is tilted to one side and moved. When the movement value of the display panel610measured by the third sensor units621and622is different from the rotation value of the slot disk624measured by the fourth sensor unit623, a determination may be made that there is an error in the operation of the display panel610.

When a determination is made in step S820that there is no error in the operation of the display panel610, the operation of the display panel610is maintained (S830).

When a determination is made in step S820that there is an error in the operation of the display panel610, the motor127is stopped and a warning signal is sent (S840). The motor127may be disposed on one side of the cylindrical member625. The motor127may be disposed on the other side of the cylindrical member625at which the slot disk624is disposed, with the cylindrical member625as a reference. The motor127may rotate the cylindrical member625using gears, belt, or the like. When a determination is made that there is an error in the operation of the display panel610, the control unit may stop driving the motor127to prevent damage to the display panel610.

A cause of the error in an operation of the display panel610is determined (S850). The control unit may determine whether a cause of the error in the operation of the display panel610is an operation error caused by a defect inside the display device600or an operation error caused by an external force from the outside of the display device600. Step S850will be described in detail with reference toFIG.9.

Referring toFIG.9, a determination is made as to whether an external force has been sensed (S910). The fifth sensor unit630may sense an external force or object from a upward direction of the display panel610. The fifth sensor unit630may determine the presence or absence of an object located within the exposure range of the display panel610.

When a determination is made in step S910that no external force is sensed, a determination is made that the operation error has occurred due to the internal defect of the display device600(S920). When the fifth sensor unit630measures that there is no external force or object from the upward direction of the display device600, the control unit determines that the malfunction is not caused by the external force or object. That is, a determination may be made that the malfunction has occurred due to the internal defect of the display device600.

A warning message due to the internal defect is sent (S930). When the control unit determines in step S920that the malfunction has occurred due to the internal defect of the display device600, the control unit sends the warning message due to the internal defect. Here, the warning message may be sent to the user using an audio output device or the like included inside the vehicle.

When a determination is made in step S910that an external force has been sensed, a warning message for an external force is sent (S940). When the fifth sensor unit630measures the external force and the control unit determines that the external force from the upward direction of the display device600is sensed, the warning message for an external force is sent. Here, for the warning message for an external force, for example, a guidance message such as “There is concern about damage to the display” and “Please remove objects around the display” may be sent using the audio output device or the like included inside the vehicle.

A determination is made as to whether an external force is continuously sensed (S950). The control unit may continuously receive information on whether an external force is sensed from the fifth sensor unit630.

In step S950, when a determination is made that an external force is continuously sensed, a warning message for an external force is continuously sent. When a determination is made that an external force is continuously sensed in the display device600, the same warning message as in step S940may be continuously sent.