KR102452052B1 - Foldable display apparatus - Google Patents

Abstract

SUMMARY OF THE INVENTION It is an object of the present invention to provide a foldable display device capable of detecting the degree of bending of a display panel in a frequency band or time period in which the noise level is small. To this end, a foldable display device according to the present invention includes a foldable display panel, a driver for driving data lines and gate lines provided in the foldable display panel, and at least two devices provided in a non-display area of the foldable display panel. and a bending analysis unit that analyzes the degree of bending of the foldable display panel using bending sensors. The bending analyzer may analyze noise generated from the foldable display panel during a noise analysis period to extract at least one of a frequency band in which the noise is minimized or a time period in which the noise is minimized, and the frequency band or The degree of bending of the foldable display panel is analyzed using at least one of the time periods.

Description

Foldable display device {FOLDABLE DISPLAY APPARATUS}

The present invention relates to a foldable display, and more particularly, to a foldable display having a bend sensor.

Types of display devices include a liquid crystal display device (LCD), an organic light emitting display device (OLED), an electrophoretic display device (EPD), and the like.

However, in the conventional display device, a glass substrate is used to withstand high heat generated during the manufacturing process of the display device. Therefore, there is a limit to making the conventional display device light, thin, or flexible.

Accordingly, in recent years, a flexible display device capable of maintaining display performance even when bent like paper has been manufactured by using a flexible material that can be folded and unfolded, such as a plastic film, instead of a glass substrate having no flexibility.

In particular, among flexible display devices, a display device that is folded in half is referred to as a foldable display device.

By understanding the degree of bending of the foldable display, various interfaces may be implemented in the foldable display.

To this end, a bending sensor may be mounted in the non-display area of the foldable display to determine the degree of bending of the foldable display.

1 is an exemplary diagram illustrating an operation principle of a bending sensor used in a conventional foldable display device.

In order to determine the degree of bending of the foldable display, as shown in FIG. 1 , a bending sensor 10 , a power supply unit 20 , a bridge circuit 40 , and a voltage measuring unit for measuring the voltage of the bridge circuit ( 30) can be used.

For example, when the bending sensor 10 is provided in the foldable display device and the power supply unit 20 supplies a bending driving signal to the bending sensor 10 and the bridge circuit 40 , the bridge circuit The voltage measured by the voltage measuring unit 30 is different according to the first resistor R1, the second resistor R2, the third resistor R3, and the resistance value of the bending sensor 10 in (40). can

For example, when the foldable display device is folded and the bending sensor 10 is folded, the voltage measured by the voltage measuring unit 30 and the voltage measuring unit 30 when the foldable display device is unfolded ) may be different from each other. Also, the voltage measured by the voltage measuring unit 30 may be different according to the folded size of the bending sensor 10 .

Accordingly, the degree of bending of the foldable display may be determined by measuring the voltage.

However, the bending detection signal received by the bending sensor 10 may be affected by various components of the foldable display device.

For example, the bending detection signal may be affected by a touch driving signal supplied to a touch panel provided in the foldable display device during a touch detection period, and may be affected by a touch driving signal provided in the foldable display device during an image display period. It may be affected by data voltages and gate pulses supplied to the data lines and gate lines.

When noise is added to the bending detection signal by the above-described signals, it is difficult to accurately determine the degree of bending of the foldable display device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a foldable display device that detects the degree of bending of a display panel in a frequency band or time period in which the noise level is small.

A foldable display device according to the present invention for achieving the above object includes a foldable display panel, a driver for driving data lines and gate lines provided in the foldable display panel, and a non-display area of the foldable display panel and a bending analyzer that analyzes the degree of bending of the foldable display panel using at least two bending sensors provided in the . The bending analyzer may analyze noise generated from the foldable display panel during a noise analysis period to extract at least one of a frequency band in which the noise is minimized or a time period in which the noise is minimized, and the frequency band or The degree of bending of the foldable display panel is analyzed using at least one of the time periods.

According to the present invention, the degree of bending can be accurately grasped.

1 is an exemplary diagram illustrating an operation principle of a bending sensor used in a conventional foldable display device;
2 is an exemplary diagram schematically illustrating the configuration of a foldable display device according to the present invention.
3 is an exemplary view showing the size of noise analyzed by the bending analyzer applied to the present invention for each time period.
4 is an exemplary diagram illustrating a time period in which a bending drive signal is output from a bending analysis unit applied to the present invention.
5 is an exemplary diagram illustrating noise analyzed by a bending analyzer applied to the present invention for each frequency.
6 is an exemplary diagram illustrating a waveform of a bending drive signal output from a bending analyzer applied to the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and those of ordinary skill in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the present invention is only defined by the scope of the claims.

It should be noted that in the present specification, in adding reference numbers to the components of each drawing, the same numbers are used for the same components, even if they are indicated on different drawings, as much as possible.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative and the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless specifically stated otherwise.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described as 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

The term 'at least one' should be understood to include all possible combinations of one or more related items. For example, the meaning of 'at least one of the first item, the second item and the third item' is not only the first item, the second item, or the third item respectively, but also 2 of the first item, the second item and the third item. It means a combination of all items that can be presented from more than one.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

Each feature of the various embodiments of the present invention can be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. may be

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exemplary diagram schematically illustrating the configuration of a foldable display device according to the present invention.

As shown in FIG. 2 , the foldable display device according to the present invention provides a foldable display panel 100 on which an image is displayed, detects the presence or absence of a touch on the foldable display panel 100, or detects the foldable display panel Using the driver 200 for driving the data lines and gate lines provided in 100 and at least two bending sensors S1 and S2 provided in the non-display area NAA of the foldable display panel, and a bending analysis unit 300 that analyzes the degree of bending of the foldable display panel 100 .

In particular, the bending analyzer 300 analyzes the noise generated by the foldable display panel 100 during the noise analysis period, and at least any one of a frequency band in which the noise is minimized or a time period in which the noise is minimized is analyzed. one is extracted, and the degree of bending of the foldable display panel 100 is analyzed using at least one of the frequency band and the time period during the bending detection period.

First, the foldable display panel 100 may be a flexible display panel using a flexible substrate. For example, the foldable display panel 100 includes a flexible organic light emitting display panel, a flexible electrophoretic display panel, and a flexible liquid crystal display panel. ), or a flexible electro-wetting display panel.

The flexible substrate may be made of a plastic material. For example, the flexible substrate may be made of any one of Polyimide (PI), Polycarbonate (PC), Polyethylenapthanate (PEN), Cyclic Olefin Polymer (COP), Polyethyleneterephthalate (PET), Polynorborneen (PNB), and Polyethersulfone (PES). can be made with

The foldable display panel 100 includes a display area AA and a non-display area NAA surrounding the display area AA.

Pixels for displaying an image are provided in the display area AA. Each of the pixels includes a display device that displays an image corresponding to the data voltage. Here, the display device may be an organic light emitting device, a liquid crystal display device, an electrophoretic device, or an electrowetting display device.

Gate lines for supplying a gate pulse to the pixels and data lines for supplying a data voltage to the pixels are provided in the display area AA.

The bending sensors S1 and S2 are provided in the non-display area AA.

The driver 200 may be directly mounted on the non-display area NAA to be connected to the data lines and the gate lines. In addition, the driving unit 200 may be attached to a flexible film, the flexible film may be attached to the non-display area NAA, and may be connected to the data lines and the gate lines through the flexible film. have.

The bending analyzer 300 may be directly mounted on the non-display area NAA to be connected to the bending sensors S1 and S2 . In addition, the bending analysis unit 300 may be attached to the flexible film, the flexible film may be attached to the non-display area NAA, and the bending sensors S1 and S2 through the flexible film can be connected

When both the bending analysis unit 300 and the driving unit 200 are attached to the flexible film, the bending analysis unit 300 and the driving unit 200 may be attached to one flexible film, or different flexible films. Each may be attached to a film.

The foldable display panel 100 may include a touch panel for sensing a touch. After the touch panel is manufactured independently of the foldable display panel 100 , the touch panel may be attached to the foldable display panel 100 , or may be embedded in the foldable display panel 100 .

In this case, the touch screen may further include a touch sensing unit that supplies a touch driving signal to the touch panel and determines whether there is a touch on the touch panel using touch sensing signals received from the touch panel.

Second, as described above, the driver 200 sequentially outputs a gate pulse to the gate lines and supplies a data voltage to the data lines.

To this end, the driver 200 may include a gate driver that sequentially outputs the gate pulse and a data driver that outputs the data voltages.

The gate driver may be directly embedded in the non-display area. This type of gate driver is called a gate-in-panel type gate driver.

The driving unit 200 may further include a touch sensing unit that supplies a touch driving signal to the touch panel and analyzes the sensing signals received from the touch panel to determine whether there is a touch on the touch panel.

In addition, the driving unit 200 may further include a driving control unit for controlling functions of the gate driver, the data driver, and the touch sensing unit. However, the driving control unit may be mounted or connected to the foldable display panel 100 independently of the driving unit 200 .

Third, the bending analysis unit 300 bends the foldable display panel 100 using at least two bending sensors S1 and S2 provided in the non-display area NAA of the foldable display panel. It performs the function of analyzing the degree.

The bending analyzer 300 analyzes the noise generated by the foldable display panel 100 during the noise analysis period, and at least one of a frequency band in which the noise is minimized or a time period in which the noise is minimized is analyzed. to extract

The noise analysis period may arrive at a preset time or whenever a preset event is received from an external system.

In the first embodiment, the bending analysis unit 300 receives a bending drive signal having an arbitrarily set frequency band (hereinafter simply referred to as an 'arbitrarily set frequency band') in the time period that arrives after the noise analysis period. After output to the bending sensors S1 and S2, the degree of bending of the foldable display panel 100 may be determined using bending detection signals received by the bending sensors S1 and S2. In this case, the bending detection period corresponds to the time zone. For example, if the first time period extracted in the first noise analysis period is the start time of each frame, the bending analyzer 300 bends the start time of each frame that arrives after the first noise analysis period. Set as the start time of the detection period. Accordingly, the bending analysis unit 300 outputs a bending drive signal having the arbitrary set frequency band for a preset period from the start of each frame, and then detects bending received through the bending sensors S1 and S2. The degree of bending of the foldable display panel 100 may be determined using the signals. If the second time period extracted in the second noise analysis period, which arrives after the first noise analysis period, is in the middle of every frame, the bending analysis unit 300 performs every frame that arrives after the second noise analysis period. is set as the start point of the bending detection period. Accordingly, the bending analysis unit 300 outputs a bending drive signal having the arbitrary set frequency band for a preset period from the middle of every frame, and then uses the bending detection signals received through the bending sensors to fold the foldable The degree of bending of the display panel can be grasped. If the third time period extracted in the third noise analysis period is the end point of each frame, the bending analysis unit 300 sets the end point of each frame that arrives after the third noise analysis period as the start time of the bending detection period. set to Accordingly, the bending analysis unit 300 outputs a bending drive signal having the arbitrary set frequency band for a preset period from the end point of each frame, and then uses the bending detection signals received through the bending sensors to fold the foldable The degree of bending of the display panel can be grasped.

In the second embodiment, the bending analysis unit 300 outputs the bending drive signal having the frequency band to the bending sensors S1 and S2 in the bending detection period that comes after the noise analysis period. , the degree of bending of the foldable display panel 100 may be determined using bending detection signals received by the bending sensors S1 and S2. In this case, the bending detection period arrives at an arbitrarily set period. For example, the bending detection period may arrive every one frame period during which one image is output, or may come every at least two frame periods, or each one blank period in which an image is not output. Alternatively, it may arrive at least every two blank periods. In this case, the timing at which the bending drive signal is output may be set to be the same in all bending detection periods that come after the noise analysis period. In addition, the bending sensing period may be shorter or longer than one frame period, and may be shorter or longer than one blank period.

In the third embodiment, the bending analysis unit 300 analyzes the bending degree of the foldable display panel 100 using both a frequency band in which the noise is minimized and a time period in which the noise is minimized. can

For example, the bending analysis unit 300 supplies a bending drive signal having the frequency band to the bending sensors in the time period that arrives after the noise analysis period, and according to the bending drive signal, By analyzing the bending detection signals received from the bending sensors, the degree of bending of the foldable display panel may be analyzed.

Information on the degree of bending of the foldable display panel 100 analyzed by the bending analyzer 300 is transmitted to the external system 400 .

The external system 400 drives various electronic products including the foldable display device according to the present invention. For example, when the electronic product is a tablet PC, the external system 400 generates various types of image data and transmits them to the foldable display device. In addition, when the electronic product is a smartphone, the external system 400 transmits various image data received from the outside or various image data generated by the smartphone to the foldable display device.

Methods of driving a foldable display device using the present invention are as follows.

For example, as a result of analyzing the degree of bending, when the foldable display panel 100 is folded to have an angle between 45 degrees and 80 degrees, the external system 400 may 100), a vending machine capable of inputting text is displayed on one side of the foldable display panel 100 , and image data is generated so that text input through the vending machine can be output on the other folded side of the foldable display panel 100 . After that, the image data may be transmitted to the driving unit 200 .

In addition, as a result of analyzing the degree of bending, when the foldable display panel 100 is fully unfolded to form 180 degrees, the external system 400 may output an image through the entire foldable display panel 100 . So, after generating the image data, the image data may be transmitted to the driving unit 200 .

The configuration and function of the bending analysis unit 300 will be described in detail below with reference to FIGS. 3 to 7 .

3 is an exemplary diagram showing the magnitude of the noise analyzed by the bending analyzer applied to the present invention for each time period, and FIG. 4 is an exemplary view showing the time period during which the bending drive signal is output by the bending analyzer applied to the present invention.

The bending analyzer 300 determines the degree of bending of the foldable display panel 100 using at least two bending sensors S1 and S2 provided in the non-display area NAA of the foldable display panel. perform the analysis function.

In particular, the bending analyzer 300 analyzes the noise generated by the foldable display panel 100 during the noise analysis period to at least one of a frequency band in which the noise is minimized or a time period in which the noise is minimized. extract any one

Hereinafter, with reference to FIGS. 3 and 4 , the bending analysis unit 300 transmits the bending drive signal having the arbitrary set frequency band to the bending sensors S1 in the time period that arrives after the noise analysis period. , S2) and then using the bending detection signals to analyze the degree of bending of the foldable display panel 100 will be described. That is, a method of analyzing the bending degree of the foldable display panel 100 by extracting a time period in which the noise is minimized by the bending analyzer 300 is described below.

For example, the magnitudes of the noises analyzed by the bending analyzer 300 may be classified by time period, as shown in FIG. 3 .

When the noise analysis period lasts for three frames (Frame1, Frame2, Frame3) and the noises are measured for each of a plurality of frames (Frame1, Frame2, Frame3), as shown in FIG. 3 , every frame is The size of the noises when a predetermined period has elapsed from the start may be analyzed to be smaller than the noises of other time periods. In FIG. 3 , areas A1, A2, and A3 represent time periods in which noises having a size smaller than noises in other time periods are generated.

In the following description, it is assumed that the A1 area, the A2 area, and the A3 area are included in a time period corresponding to 1/5 of the total period of the frame from the start of the frame.

The bending analyzer 300 may set a time period corresponding to 1/5 of the entire period of each frame as the bending detection period from the start of each frame by using the analysis result as shown in FIG. 3 .

In more detail, the bending analysis unit 300 may analyze the noise generated from the foldable display panel 100 during the noise analysis period, and set a time period in which the noise level is smallest as the bending detection period. have.

The bending analysis unit 300 supplies a bending drive signal to the bending sensors S1 and S2 in the time period extracted through the above process, and according to the bending drive signal, the bending sensors S1 and S2 ), it is possible to analyze the bending degree of the foldable display panel 100 by analyzing the bending detection signals.

Accordingly, the time period during which the bending drive signals TS are output to the bending sensors S1 and S2 may be variously set as shown in FIG. 4 . For example, FIG. 4 shows time from the start of every frame.

In this case, the bending drive signal TS output in the X time zone shown in FIG. 4 represents the first time zone extracted based on the graph shown in FIG. 3 during the first noise analysis period. That is, X represents a first time zone corresponding to 1/5 of the entire period of the frame from the start of the frame. Accordingly, the bending analysis unit 300 outputs the bending driving signal having the arbitrary set frequency band in the first time period that arrives after the first noise analysis period.

In addition, Y represents the second time period identified as a result of analyzing noise for three frames in the second noise analysis period, and Z is the second time period identified as a result of analyzing noise for three frames in the third noise analysis period. Shows 3 time zones.

In this case, although the first time zone, the second time zone, and the third time zone are shown in one time graph in FIG. 4, the first time zone, the second time zone, and the third time zone are independently used time to be.

For example, after the first noise analysis period, the bending drive signal is output for a predetermined period every first time period, and after the second noise analysis period, the bending drive signal is output for a predetermined period every second time period and, after the third noise analysis period, the bending driving signal is output for a predetermined period every third time period.

In more detail, time periods in which the noise level is the smallest, analyzed in each noise analysis period, may be different from each other. Accordingly, start times of the bending detection periods may be different from each other based on the time point of the frame.

The bending analyzer 300 may analyze the noise every preset time or whenever a preset event is received from an external system.

For example, the noise analysis period may arrive at a preset time or whenever a preset event is received from an external system.

When the noise analysis period is set to every 10 minutes, the bending analysis unit 300 analyzes the noises every 10 minutes elapse, and sets the time period with the smallest noise as the bending detection period. have. Thereafter, the bending analysis unit 300 determines the degree of bending using the time period. After another 10 minutes have elapsed after setting the time period, the bending analysis unit 300 may analyze the noises again, and set a time period in which the noise level is smallest as the bending detection period.

As another example, if it is set to analyze the noise when an event such as power on, power off, or charging occurs from the external system 400, the bending analyzer 300 may 400), when an event such as power-on, power-off, or charging is received, the noise may be analyzed, and a time period with the smallest noise may be set as the bending detection period.

In more detail, the noise analysis period may be set by various setting methods, and the bending analysis unit 300 performs bending of the foldable display panel 100 using the time period analyzed during the noise analysis period. degree can be analyzed.

Thereafter, when another noise analysis period arrives, the bending analyzer 300 may analyze the degree of bending of the foldable display panel 100 after setting the time period again.

5 is an exemplary view showing the noise analyzed by the bending analyzer applied to the present invention for each frequency, and FIG. 6 is an exemplary view showing the waveform of the bending driving signal output from the bending analyzing unit applied to the present invention.

The bending analyzer 300 determines the degree of bending of the foldable display panel 100 using at least two bending sensors S1 and S2 provided in the non-display area NAA of the foldable display panel. perform the analysis function.

In particular, the bending analyzer 300 analyzes the noise generated by the foldable display panel 100 during the noise analysis period to at least one of a frequency band in which the noise is minimized or a time period in which the noise is minimized. extract any one

Hereinafter, with reference to FIGS. 5 and 6 , the bending analysis unit 300 transmits the bending driving signal having the frequency band to the bending sensors S1 during the bending detection period that comes after the noise analysis period. , S2) and then using the bending detection signals to analyze the degree of bending of the foldable display panel 100 will be described. The frequency band is a frequency band in which noise is minimized. That is, a method for analyzing the bending degree of the foldable display panel 100 by extracting a frequency band in which the noise is minimized by the bending analyzer 300 is described below.

For example, when the noises analyzed during the noise analysis period have frequency bands as shown in FIG. 5 , it can be seen that the magnitude of noises between 1000 Hz and 250 Hz is smaller than noises of other frequency bands.

Accordingly, the bending analyzer 300 selects a frequency band having the smallest noise level among frequency bands between 1000 Hz and 250 Hz. In FIG. 6 , the first bending drive signal TS1 has a first frequency band extracted during the first noise analysis period, and the second bending drive signal TS2 has a second frequency band extracted during the second noise analysis period. , and the third bending driving signal TS3 has a third frequency band extracted during the third noise analysis period.

The first frequency band is larger than the second frequency band, and the second frequency band is larger than the third frequency band.

In a bending detection period that follows the first noise analysis period, the bending analysis unit 300 outputs a bending drive signal having the first frequency band to the bending sensors S1 and S2. The bending analyzer 300 detects the degree of bending of the foldable display panel 100 by using the detection signals received from the bending sensors S1 and S2 .

In a bending detection period that follows the second noise analysis period, the bending analysis unit 300 outputs the bending driving signal having the second frequency band to the bending sensors S1 and S2. The bending analyzer 300 detects the degree of bending of the foldable display panel 100 by using the detection signals received from the bending sensors S1 and S2 .

In a bending detection period that follows the third noise analysis period, the bending analysis unit 300 outputs a bending drive signal having the third frequency band to the bending sensors S1 and S2. The bending analyzer 300 detects the degree of bending of the foldable display panel 100 by using the detection signals received from the bending sensors S1 and S2 .

As described above, the bending analyzer 300 may extract the frequency band every preset time or whenever a preset event is received from an external system.

The third embodiment in which the bending analyzer 300 analyzes the degree of bending of the foldable display panel 100 using both a frequency band in which the noise is minimized and a time period in which the noise is minimized is used. , by combining the first embodiment and the second embodiment described above.

For example, the bending analysis unit 300 supplies a bending drive signal having the frequency band to the bending sensors in the time period that arrives after the noise analysis period, and according to the bending drive signal, By analyzing the bending detection signals received from the bending sensors, the degree of bending of the foldable display panel may be analyzed.

7 is an exemplary diagram showing the internal configuration of a bending analysis unit applied to the present invention, and FIG. 8 is a block diagram of an embodiment of the bending analysis unit applied to the present invention.

As described above, the bending analyzer 300 analyzes noise generated from the foldable display panel during the noise analysis period, and the frequency band in which the noise is minimized or the time period in which the noise is minimized at least one of the selected components is extracted, and the degree of bending of the foldable display panel is analyzed using at least one of the frequency band and the time period.

In the first embodiment, the bending analysis unit 300 supplies a bending drive signal to the bending sensors in the time period that arrives after the noise analysis period, and according to the bending drive signal, the bending sensors By analyzing the bending detection signals received from the display panel, the degree of bending of the foldable display panel is analyzed.

In the second embodiment, the bending analysis unit 300 supplies the bending drive signal having the frequency band to the bending sensors in a bending detection period that comes after the noise analysis period, and performs the bending operation The bending degree of the foldable display panel is analyzed by analyzing bending detection signals received from the bending sensors according to the signals.

In the third embodiment, the bending analysis unit 300 supplies the bending drive signal having the frequency band to the bending sensors in the time period that arrives after the noise analysis period, and the bending drive signal Accordingly, bending detection signals received from the bending sensors are analyzed to analyze the degree of bending of the foldable display panel.

In this case, the bending analyzer 300 may extract at least one of the frequency band or the time zone every preset time or whenever a preset event is received from an external system.

In particular, during the noise analysis period in which the bending drive signal is not supplied to the bending sensor, the bending analysis unit 300 analyzes the bending detection signals received from the bending sensors, and at least in the frequency band or the time period. extract one

To this end, as shown in FIG. 7 , the bending analyzer 300 includes a bridge circuit 320 that outputs a voltage according to a change in resistance of the bending sensors S1 and S2 , and the bridge circuit 320 . and a power supply unit 330 and a control unit 310 for supplying the bending driving signal.

The control unit 310 controls the power supply unit 330 so that the power supply unit 330 does not output the bending driving signal during the noise analysis period. The control unit 310 analyzes the voltage of the bridge circuit 320 to extract the frequency band applied to the second embodiment. The control unit 310 controls the power supply unit 330 to output the bending drive signal having the frequency band in the bending detection period that comes after the noise analysis period. The control unit 310 analyzes the degree of bending of the foldable display panel 100 by analyzing the voltage of the bridge circuit 320 .

In addition, the control unit 310 controls the power supply unit 330 so that the power supply unit 330 does not output the bending driving signal during the noise analysis period, and analyzes the voltage of the bridge circuit 320 to The time zone applied to the first embodiment is extracted. The control unit 310 controls the power supply unit 330 so that the power supply unit outputs the bending drive signal during the time period after the noise analysis period. The control unit 310 analyzes the degree of bending of the foldable display panel 100 by analyzing the voltage of the bridge circuit 320 .

In addition, the control unit 310 extracts the time zone and the frequency band applied to the third embodiment in the noise analysis period, and then in the time period that comes after the noise analysis period, bending having the frequency band. The power supply unit 330 may be controlled so that a driving signal may be supplied to the bending sensors S1 and S2. In this case, the controller 310 may analyze the bending degree of the foldable display panel 100 by analyzing the bending detection signals received from the bending sensors according to the bending driving signal.

Among the four resistors constituting the bridge circuit 320 , the first resistor R1 and the fourth resistor R4 connected in parallel are the bending sensor S1 disposed in the non-display area NAA. , S2).

In the bridge circuit 320, the voltage Va at the node between the first resistor R1 and the third resistor R3 and the node between the second resistor R2 and the fourth resistor R4 A voltage (Vab = Va-Vb) between the voltages Vb may be expressed as [R3/(R1+R3) - R4/(R2+R4)] x Vs. Vs is the voltage of the bending driving signal output from the power supply unit 330 .

The controller 310 may include an extractor 311 and a control signal generator 312 as shown in FIG. 8 .

The extractor 311 extracts at least one of the frequency band and the time period by analyzing the noises during the noise analysis period. The extractor 311 analyzes the degree of bending of the foldable display panel 100 using the detection signals received through the bridge circuit 320 during the bending detection period. For example, when the voltage Vab measured by the bridge circuit 320 is greater than a preset value, the extractor 311 may determine that the foldable display panel 100 is completely folded, and the voltage Vab ) is less than a preset value, it may be determined that the foldable display panel 100 is unfolded, and the degree of bending of the foldable display panel may be determined according to a specific size of the voltage Vab. Also, the extractor 311 may determine the degree of bending of the foldable display panel by using a concept opposite to the above-described method.

The control signal generating unit 312 generates a control signal under the control of the extracting unit 311 , and the control signal is transmitted to the power supply unit 330 .

The power supply unit 330 may include a frequency band varying unit 331 for varying the frequency band and a time varying unit 332 for varying the time zone.

The power supply unit 330 uses at least one of the frequency band variable unit 331 and the time variable unit 332 to perform the bending driving according to a control signal transmitted from the control signal generating unit 312 . A signal may be output to the bridge circuit 320 .

The present invention described above is summarized as follows.

The present invention analyzes the noise of the foldable display panel 100 to extract a frequency band in which noise is minimized or a time period in which noise is minimized, and then uses the time period to vary the timing at which the bending drive signal is output, or (First embodiment), or by varying the frequency of the bending drive signal output to the bending sensor using the frequency band (Second embodiment), or outputting the bending drive signal using the time zone and the frequency band Both the timing and the frequency of the bending drive signal can be varied (third embodiment)

According to the present invention, a bending drive signal having an optimal frequency band and time period can be output. Accordingly, the degree of bending of the foldable display panel 100 may be accurately determined.

Since a person directly folds the foldable display panel 100 , in the process of determining the degree of bending in the foldable display panel 100 , there is no need for a report rate faster than the report rate required for touch sensing. Therefore, by minimizing the bending detection period, the noise period can be avoided. In other words, since the user directly folds the foldable display panel, the movement of the foldable display panel is slower than the movement of the finger in a general touch. Therefore, the report rate for detecting bending need not be faster than the report rate used for detecting touch. In addition, although there are more than several hundred sensing points for touch sensing, one sensing point for bending sensing is within one, or two, or several tens. Therefore, the time consumed for sensing is small.

In the present invention, in the noise analysis period in which the bending drive signal is not output, by analyzing the noise component in terms of frequency, a frequency band except for a frequency band having many noise components can be set.

In addition, during the noise analysis period, by dividing the noise component into multiples (120, 180, 240 Hz) of the image display frequency on the time axis and analyzing it, the time period in which the noise component is least generated can be predicted, and the bending drive signal is output during the time period. Thus, the degree of bending can be grasped.

According to the present invention, the angle sensing performance of the foldable display panel can be improved.

In the second embodiment, the method of extracting the frequency band is summarized as follows.

First, in the method of collecting noise data for noise analysis, the voltage of the power supply unit 330 shown in FIG. 7 is fixed to 0V, and then the value output through the Amp and ADC of the control unit 310 is converted into noise data. judge In addition, when the voltage of the power supply unit 330 is set to Vcc (5V, 3.3V, etc.), the value output through the Amp and ADC of the control unit 310 is determined as sensing data.

Noise from a device including the foldable display panel exhibits several characteristics. First, there are frequency-centered noise according to power, the driving frequency or touch frequency of the display, and noise on the time axis according to the display driving.

Accordingly, the present invention uses a method of outputting a bending drive signal (sensing clock) after each noise is independently analyzed in order to remove two types of noise generated in the frequency and time axes.

The bending analyzer 300 detects a main frequency band of the noise after continuously sensing the noise. Thereafter, the bending analyzer 300 checks whether the frequency band of the bending drive signal currently used coincides with the frequency band in which the least noise is generated, and if they do not match, the noise is avoided by changing the frequency.

In this case, the total frequency usable in the foldable display device may be compared with the frequency of the noise, or several preset optimal frequencies may be compared with the frequency of the noise.

The period of analyzing the noise frequency may be one frame (60 Hz, 120 Hz, etc.) in which an image is output, and may last for several frames.

Also, the noise analysis may be continuously performed for a preset period while the foldable display is turned on. Also, the noise analysis may be performed temporarily when a specific event occurs in the foldable display device, and then the frequency band or time period analyzed in the noise analysis may be used until another event occurs.

Here, the specific event may be an event in which a user plugs in a charger, an event in which a change in temperature occurs, or an event in which the brightness of the foldable display panel is adjusted.

In the first embodiment, the method of extracting the time zone is summarized as follows.

In the time axis analysis, as in the frequency analysis, there is a noise measurement period, and after the noise is continuously sensed, the main time period of the noise is identified. When the foldable display panel is driven, a lot of noise is generated when the thin film transistor is operated, so a system for avoiding noise on the time axis is needed.

Noise data is stored on the time axis, and a place with the least noise is extracted from the first frame. Thereafter, in the second frame, bending sensing may be performed at a position having the least noise in the first frame.

Here, the data accumulation for noise analysis may be continued until an event that a change of the situation occurs in the external system comes, and when the situation changes, it is newly accumulated. In this case, you may continue to accumulate.

Noise in several frames is converted into noise of a unit frame using methods such as integration and averaging, and bending sensing is performed at a point where the minimum noise is generated in the unit frame.

Those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: foldable display panel 200: driving unit
300: bending analysis unit 400: external system

Claims (8)

foldable display panel;
a driver driving data lines and gate lines provided in the foldable display panel; and
and a bending analysis unit that analyzes a degree of bending of the foldable display panel using at least two bending sensors provided in a non-display area of the foldable display panel;
The bending analysis unit analyzes noise generated in the foldable display panel during a noise analysis period to extract at least one of a frequency band in which the noise is minimized or a time period in which the noise is minimized,
The bending analysis unit supplies a bending drive signal to the bending sensors in the time period that arrives after the noise analysis period, and analyzes the bending detection signals received from the bending sensors according to the bending drive signal, the Analyze the bending degree of the foldable display panel,
The time zone corresponds to a bending detection period. The method of claim 1,
If the time period extracted in the noise analysis period is the start of each frame,
The bending analysis unit sets a start time of every frame that arrives after the noise analysis period as a start time of the bending detection period,
The bending analyzer supplies the bending driving signal having a preset frequency band for a preset period from the start of each frame to the bending sensors, and analyzes the bending detection signals received from the bending sensors according to the bending driving signal. A foldable display device for analyzing the degree of bending of the foldable display panel by analysis. The method of claim 1,
The time period extracted in the first noise analysis period of the noise analysis period is the first time period, the time period extracted in the second noise analysis period is the second time period, and the time period extracted in the third noise analysis period is the third time period. when the time
When the first time period is the start time of each frame, the bending analysis unit sets a start time of every frame that arrives after the first noise analysis period as the start time of the bending detection period, and the bending analyzer The bending driving signal having a preset frequency band is supplied to the bending sensors for a preset period from the start of the frame, and bending detection signals received from the bending sensors are analyzed according to the bending driving signal to analyze the foldable Analyze the bending degree of the display panel,
If the second time period is in the middle of every frame, the bending analysis unit sets the middle of every frame that arrives after the second noise analysis period as the start time of the bending detection period, and the bending analysis unit sets the middle of each frame. supplies the bending driving signal having the preset frequency band to the bending sensors for a preset period from Analyze the degree of bending,
If the third time period is the end point of each frame, the bending analysis unit sets the end point of each frame that arrives after the third noise analysis period as the start time of the bending detection period, and the bending analysis unit sets the end point of each frame supplies the bending driving signal having the preset frequency band to the bending sensors for a preset period from A foldable display that analyzes the degree of bending. The method of claim 1,
The bending driving signal has the frequency band. The method of claim 1,
The bending analysis unit,
A foldable display device for extracting at least one of the frequency band and the time zone every preset time or whenever a preset event is received from an external system. The method of claim 1,
In the noise analysis period in which the bending drive signal is not supplied to the bending sensor, the bending analysis unit analyzes the bending detection signals received from the bending sensors, and extracts at least one of the frequency band or the time period. block display. The method of claim 1,
The bending analysis unit,
a bridge circuit outputting a voltage according to a change in resistance of the bending sensors;
a power supply supplying the bending driving signal to the bridge circuit; and
In the noise analysis period, the power supply unit controls the power supply not to output the bending drive signal, analyzes the voltage of the bridge circuit to extract the frequency band, and the bending that occurs after the noise analysis period a controller configured to control the power supply to output the bending driving signal having the frequency band during a sensing period, and to analyze the voltage of the bridge circuit to analyze the degree of bending of the foldable display panel foldable display. The method of claim 1,
The bending analysis unit,
a bridge circuit outputting a voltage according to a change in resistance of the bending sensors;
a power supply supplying the bending driving signal to the bridge circuit; and
During the noise analysis period, the power supply unit controls the power supply unit not to output the bending drive signal, the voltage of the bridge circuit is analyzed to extract the time period, and after the noise analysis period, the power supply unit is and a control unit controlling the power supply unit to output the bending driving signal at a time period, and analyzing a bending degree of the foldable display panel by analyzing a voltage of the bridge circuit.

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