TWI813289B - Display panel and operating method thereof - Google Patents

Abstract

A display panel and operating method thereof are provided. The display panel includes a pixel array and a timing controller. The timing controller controls a refresh rate of a display screen of the pixel array. In a security display mode, the timing controller switches the refresh rate among a plurality of selected refresh rates. Each one of the plurality of selected refresh rates is one of divisors of the refresh rate

Description

Display panel and its operation method

The present invention relates to a display panel and an operating method thereof, and in particular to a display panel and an operating method thereof that enable the displayed encrypted text to be photographed.

Generally speaking, encrypted text is embedded in digital data in the form of a watermark to protect the aforementioned digital data. The encrypted text switches between high grayscale values and low grayscale values according to the refresh frequency of the display screen to distinguish it from the aforementioned digital data. However, the shutter integration period of the current shooting device is very short (for example, it just corresponds to the refresh frequency of the display screen), so that the encrypted text captured by the shooting device is a complete high gray-scale value and a complete low gray-scale value. Offset, resulting in the shooting device being unable to capture the encrypted text, thereby increasing the risk of digital data being stolen or peeped.

Embodiments of the present invention provide a display panel that can reduce the risk of displayed data being stolen or peeked into.

The display panel according to the embodiment of the present invention includes a pixel array and a timing controller. The timing controller is coupled to the pixel array. The timing controller controls the refresh frequency of the display screen of the pixel array. In secure display mode, the timing controller switches the refresh rate between multiple selected refresh rates. Each selected refresh frequency is a factor of the refresh frequency.

An embodiment of the present invention further provides an operating method of a display panel. The operating method of the display panel includes the following steps: using a timing controller to control the refresh frequency of the display image of the pixel array; and in the encrypted display mode, using the timing controller to switch the refresh frequency among multiple selected refresh frequencies. Each selected refresh frequency is a factor of the refresh frequency.

Based on the above, the display panel and the operating method of the display panel according to the embodiments of the present invention can control the display screen to switch between multiple selected refresh frequencies, so that it is difficult for the shooting device to avoid the refresh time point of the display screen. Therefore, the shooting device can capture the complete display screen, thereby reducing the risk of the display screen being stolen or peeked at.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, embodiments are given below and described in detail with reference to the accompanying drawings.

Some embodiments of the present invention will be described in detail with reference to the accompanying drawings. The component symbols cited in the following description will be regarded as the same or similar components when the same component symbols appear in different drawings. These embodiments are only part of the present invention and do not disclose all possible implementations of the present invention. Rather, these embodiments are only examples within the scope of the patent application of the invention.

FIG. 1 is a block diagram of a display panel according to an embodiment of the present invention. Referring to FIG. 1 , the display panel 100 may be, for example, a light-emitting diode (LED), an organic light-emitting diode (OLED), or other display panel that provides a display function. In this embodiment, the display panel 100 includes a pixel array 110 and a timing controller 120 . The pixel array 110 is coupled to the timing controller 120 .

In this embodiment, the pixel array 110 includes a plurality of light-emitting units. The number and arrangement of these light-emitting units can be arranged according to actual needs. In this embodiment, the light-emitting unit of the pixel array 110 may be, for example, a light-emitting diode (LED), a micro-light-emitting diode (Micro-LED), or an organic light-emitting diode (Organic Light Emitting Diode). OLED), Inorganic Light Emitting Diode (ILED), Submillimeter Light Emitting Diode (Mini-LED), Micro-LED (Micro-LED), Electroluminescence (EL) unit, This embodiment is not limited to laser diodes or other types of light-emitting units.

In this embodiment, the timing controller 120 can control the pixel array 110 . The timing controller 120 may be, for example, a central processing unit (CPU), or other programmable general-purpose or special-purpose microprocessor (Microprocessor), digital signal processor (Digital Signal Processor, DSP), Programmable controllers, Application Specific Integrated Circuits (ASICs), Programmable Logic Devices (PLDs) or other similar devices or combinations of these devices, which can load and execute relevant firmware body or software to realize the control function.

In this embodiment, the pixel array 110 can be controlled by the timing controller 120 to provide a display image. Specifically, in this embodiment, the timing controller 120 drives the pixel array 110 through a driving circuit (not shown), so that the pixel array 110 emits light according to the timing of the timing controller 120 to provide a display image.

FIG. 2 is a flowchart of an operating method of a display panel according to an embodiment of the present invention. Please refer to FIG. 1 and FIG. 2 , the display panel 100 can perform the following steps S210 to S220 to operate. In this embodiment, steps S210 to S220 may be applied to the following exemplary situations.

In this embodiment, the display panel 100 can operate in a normal display mode or in an encrypted display mode. In the general display mode, the display image displayed by the pixel array 110 includes general data. In the encrypted display mode, the display image displayed by the pixel array 110 includes general data and encrypted data. The encrypted data may be, for example, a watermark (also known as a digital watermark) to indicate ownership of general data. In this embodiment, the encrypted data can be overlapped with the normal data to form a display screen to protect the normal data.

In step S210 , the refresh frequency (or refresh rate) of the display screen of the pixel array 110 is controlled through the timing controller 120 . That is to say, the pixel array 110 is controlled by the timing controller 120 to update the display screen at a refresh frequency.

In this embodiment, the timing controller 120 can also determine whether the display panel 100 operates in the normal display mode or in the encrypted display mode. When the display panel 100 operates in the encrypted display mode, the display panel 100 executes step S220.

In step S220 , in the encrypted display mode, the timing controller 120 switches the refresh frequency among a plurality of selected refresh frequencies, so that the pixel array 110 updates the display screen with the switched selected refresh frequencies.

It should be noted that there is a magnification relationship between each selected refresh frequency and the refresh frequency. Specifically, in this embodiment, each selected refresh frequency is a factor of the refresh frequency. For example, the refresh frequency of the display screen (eg, the default refresh frequency) is 1/240 Hertz (Hz). The selected refresh frequency may be, for example, 1/240, 1/120, 1/60, 1/30 Hz, etc.

In this embodiment, the frequency switching action performed in step S220 can switch between any two different selected refresh frequencies (for example, 1/240 Hz and 1/120 Hz). In some embodiments, the frequency switching action performed in step S220 may switch between more than two different selected refresh frequencies. In this embodiment, the frequency switching action performed in step S220 can be performed at any time point, and this embodiment is not limited. That is to say, the refresh frequency of the display image output by the display panel 100 can be any permutation and combination of multiple selected refresh frequencies.

In this embodiment, each selected refresh frequency is greater than 60 Hz to prevent human eyes from experiencing flickering or freezing when browsing the display screen.

On the other hand, when the display panel 100 operates in the general display mode, the timing controller 120 can set the refresh frequency to a fixed value (for example, a preset refresh frequency, 1/240 Hz), and the pixel array 110 to a fixed value. refresh frequency to update the display screen.

It is worth mentioning here that in the encrypted display mode, the timing controller 120 controls the refresh frequency of the display screen, so that the refresh frequency can be switched between different selected refresh frequencies to form a floating refresh frequency. In this way, when an external shooting device (such as a camera) captures the display screen, the floating refresh rate can be staggered with the shutter frequency of the camera, thereby preventing the camera from performing shutter integration on the refresh time point of the display screen and causing partial The data (such as encrypted data) cannot be captured by the camera. Therefore, in the encrypted display mode, the camera can capture all the data in the display screen without being able to avoid encrypted data, which can reduce the risk of the display screen being stolen or peeped.

FIG. 3 is a schematic diagram of the operation of the display panel according to the embodiment of FIG. 1 of the present invention. In FIG. 3 , the horizontal axis represents the operation time of the display panel 100 and the vertical axis represents the gray scale value. For details of the operation of the display panel 100 to perform the frequency switching operation, please refer to both FIG. 1 and FIG. 3 .

In FIG. 3 , the display panel 100 operates in the encrypted display mode. In this embodiment, the refresh frequency of the display D1 is switched between the selected refresh frequency F1 (for example, 1/240 Hz) and another selected refresh frequency F2 (for example, 1/120 Hz). The number and configuration of the selected refresh frequencies F1 and F2 in the embodiment of FIG. 3 are only examples and are not limited thereto.

In this embodiment, the timing controller 120 may perform the frequency switching action of the refresh frequency according to the set time interval. For example, after a preset time interval (for example, 480 seconds) passes, the timing controller 120 switches the selected refresh frequency F1 to the selected refresh frequency F2, and after another set time interval passes, the timing controller 120 switches the selected refresh frequency F1 to the selected refresh frequency F2. Frequency F2 switches to the selected refresh frequency F1, and so on. In some embodiments, the set time interval is generated by a random number generator in the timing controller 120 .

In this embodiment, the display screen D1 includes general data and encrypted data. In this embodiment, the encrypted data is, for example, a watermark. The general data is, for example, other background data excluding encrypted data in the display screen D1. In this embodiment, the grayscale value of the encrypted data is, for example, switched between the first grayscale value G1 and the second grayscale value G2. The grayscale value of general data (for example, the average grayscale value) is, for example, the third grayscale value G3. It should be noted that the first gray scale value G1 and the second gray scale value G2 are both different from the third gray scale value G3, so that the encrypted data can be distinguished from the general data.

In this embodiment, the sum of the first grayscale value G1 and the second grayscale value G2 of the encrypted data is equal to the third grayscale value G3 of the general data. That is to say, within any period, the total energy of the encrypted data (i.e., the sum of the first gray-scale value G1 and the second gray-scale value G2) is equal to the total energy of the general data (i.e., the third gray-scale value G3). , so that encrypted data can be embedded in general data in the form of watermarks.

In this embodiment, the camera operates during the shooting period TC. The camera can use the shooting signal C1 with the shutter frequency FC to shoot the display screen D1 to perform shutter integration on the display screen D1 during the shooting period TC. In this embodiment, the shutter frequency FC may be the same as or different from the selected refresh frequency F1 and/or F2.

It should be noted that since the encrypted data in the display screen D1 switches between the selected refresh frequencies F1 and F2, it is difficult for the camera's shutter frequency FC to align with the signal edge corresponding to the refresh frequency in the display screen D1 (for example, the selected refresh frequency F1 or F2 The rising edge of F2 and its falling edge). Therefore, during the shooting period TC, the first grayscale value G1 and the second grayscale value G2 will not cancel each other after being integrated by the shutter, so that the encrypted data can be captured by the camera.

FIG. 4 is a block diagram of a display panel according to another embodiment of the present invention. Please refer to FIG. 4 . The display panel 400 may be, for example, a liquid crystal display (LCD) and a cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp, CCFL) or a light-emitting diode (Light-Emitting Diode, LED). A display panel that provides display functions for backlight devices, etc. In this embodiment, the display panel 400 includes a pixel array 410 and a timing controller 420 . The pixel array 410 and the timing controller 420 included in the display panel 400 can be derived by referring to the relevant description of the display panel 100 and will not be repeated here.

In this embodiment, the display panel 400 further includes a backlight device 430 . The backlight device 430 is coupled to the pixel array 410 and the timing controller 420 . The backlight device 430 may be, for example, a backlight panel or other circuit or device capable of outputting backlight. The backlight device 430 may cooperate with the pixel array 410 to provide a display image. In this embodiment, the timing controller 420 can control the backlight device 430 to generate a backlight driving signal to output the backlight.

FIG. 5 is a schematic diagram of the operation of the display panel according to the embodiment of FIG. 4 of the present invention. In FIG. 5 , the horizontal axis represents the operation time of the display panel 400 and the vertical axis represents the gray scale value. For details of the operation of the display panel 400 to perform the frequency switching operation, please refer to both FIG. 4 and FIG. 5 .

In FIG. 5 , the display panel 400 operates in the encrypted display mode. In this embodiment, the refresh frequency of the display D1 is switched between the selected refresh frequency F1 (for example, 1/240 Hz) and another selected refresh frequency F2 (for example, 1/120 Hz). Regarding the frequency switching operation of the display screen D1, reference can be made to the relevant description in FIG. 3 and analogies can be made, so it will not be repeated here.

In this embodiment, the backlight D2 output by the backlight device 430 has a backlight refresh frequency F3 (for example, 1/100 Hz). It should be noted that the backlight refresh frequency F3 of the backlight D2 is different from the plurality of selected refresh frequencies of the display screen D1 (for example, the selected refresh frequencies F1 and F2).

In this embodiment, the gray scale value of the backlight D2 is, for example, switched between the fourth gray scale value G4 and the fifth gray scale value G5. The average brightness value (ie, the average grayscale value) of the backlight D2 is, for example, the sixth grayscale value G6. In this embodiment, the fourth grayscale value G4 and the fifth grayscale value G5 may be the same as or different from the first grayscale value G1 , the second grayscale value G2 and/or the third grayscale value G3 respectively.

In this embodiment, the camera operates during the shooting period TC. The camera can use the shooting signal C1 with the shutter frequency FC to shoot the display screen D1 to perform shutter integration on the display screen D1 during the shooting period TC. In this embodiment, the shutter frequency FC may be the same as or different from the selected refresh frequencies F1, F2 and/or the backlight refresh frequency F3.

It should be noted that since the encrypted data in the display D1 switches between the selected refresh frequencies F1 and F2, and with the backlight D2 having a backlight refresh frequency F3, the camera's shutter frequency FC is difficult to align with the refresh frequency corresponding to the display D1 signal edges (for example, the rising edge and falling edge of the selected refresh frequency F1 or F2). Therefore, the privacy of the encrypted data in the display screen D1 can be enhanced by staggering the backlight D2 and the encrypted data.

In summary, the display panel and its operating method according to embodiments of the present invention can control the refresh frequency of the display image to switch between different selected refresh frequencies to form a floating refresh frequency, so as to be staggered with the shutter frequency of the shooting device. Therefore, through a floating refresh frequency, the photographing device can capture the complete data (including encrypted data) in the display screen, thereby reducing the risk of the display screen being stolen or peeped. In some embodiments, the display panel used in the backlight device can also enhance the privacy of the display screen through the backlight refresh frequency of the backlight.

Although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the appended patent application scope.

100, 400: Display panel 110, 410: Pixel array 120, 420: Timing controller 430:Backlight device C1: Shooting signal D1: Display screen D2: Backlight F1, F2: Select refresh frequency F3: Backlight refresh frequency FC: shutter frequency G1: first gray level value G2: second grayscale value G3: The third gray level value G4: The fourth gray level value G5: fifth gray level value G6: The sixth gray level value S210~S220: steps TC:During filming

FIG. 1 is a block diagram of a display panel according to an embodiment of the present invention. FIG. 2 is a flowchart of an operating method of a display panel according to an embodiment of the present invention. FIG. 3 is a schematic diagram of the operation of the display panel according to the embodiment of FIG. 1 of the present invention. FIG. 4 is a block diagram of a display panel according to another embodiment of the present invention. FIG. 5 is a schematic diagram of the operation of the display panel according to the embodiment of FIG. 4 of the present invention.

100:Display panel

110: Pixel array

120: Timing controller

Claims (8)

A display panel includes: a pixel array; and a timing controller coupled to the pixel array for controlling a refresh frequency of a display screen of the pixel array, wherein in an encrypted display mode, the timing controller The controller causes the refresh frequency to switch between a plurality of selected refresh frequencies, and each selected refresh frequency is a factor of the refresh frequency. In the encrypted display mode, the display screen includes a general data and an encrypted data, and the encrypted data The sum of a first grayscale value and a second grayscale value is equal to the grayscale value of the general data. The display panel of claim 1, wherein the timing controller performs the frequency switching action of the refresh frequency according to a set time interval. The display panel of claim 1, wherein each selected refresh frequency is greater than 60 Hz. The display panel of claim 1, further comprising: a backlight device coupled to the pixel array and the timing controller, wherein the timing controller controls the backlight device to generate a backlight driving signal to output the backlight, wherein in the In the encrypted display mode, the backlight has a backlight refresh frequency that is different from the selected refresh frequencies. A method of operating a display panel, including: controlling a refresh frequency of a display screen of a pixel array through a timing controller; and In an encrypted display mode, the refresh frequency is switched between a plurality of selected refresh frequencies through the timing controller, wherein each selected refresh frequency is a factor of the refresh frequency, wherein in the encrypted display mode, the display screen includes A general data and an encrypted data, the sum of a first gray scale value and a second gray scale value of the encrypted data is equal to the gray scale value of the normal data. The operation method as described in claim 5, wherein in the encrypted display mode, the step of switching the refresh frequency between a plurality of selected refresh frequencies through the timing controller includes: using the timing controller according to a set time interval. Execute the frequency switching action of the refresh frequency. As in claim 5, the selected refresh frequency is greater than 60 Hz. The operation method described in claim 5 further includes: controlling a backlight device through the timing controller to generate a backlight drive signal to output the backlight, wherein in the encrypted display mode, the backlight has a backlight refresh frequency, and the backlight refresh rate The frequency is different from the selected refresh frequencies.

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