Light adjustment method of display device

Abstract

A dimming method of a display device is disclosed. The method comprises the steps of generating a synchronization signal, each cycle of the synchronization signal being a frame time; determining a bit value of a dithering data according to target brightness data; and determining a number of pulses needed to be modulated in the frame time according to the bit value of the dithering data, the width of one or more pulses of a pulse width modulation signal being modulated.

Description

Technical Field

[0001] This invention relates to display devices, and more particularly to a dimming method for a display device. Background Technology

[0002] With the development of technology, display devices are widely used in people's daily lives. Display devices must be able to adjust the brightness of their backlight to display images with the desired brightness and color under various ambient lighting conditions. For display devices, grayscale is the determining factor for the number of colors that can be displayed. Grayscale, also known as gray levels, refers to the degree of brightness. Dividing the luminance of primary colors according to their intensity creates grayscale levels. The higher the grayscale level a display device can generate, the more colors and image layers it can display, and the better it can display images with the desired brightness and color. Generally speaking, the higher the grayscale, the richer the displayed colors, the more delicate the image, and the easier it is to represent rich details, but it also places higher demands on the processor's internal frequency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a dimming method for a display device, addressing the shortcomings of the prior art. The dimming method for a display device is applicable to a display device and includes the following steps: generating a synchronization signal, each cycle of which is one frame time; determining the bit value of dithering data based on target brightness data; determining the number of pulses to be modulated within the frame time based on the bit value of the dithering data, thereby modulating the width of one or more pulses of a pulse width modulation signal; and driving one or more of a plurality of light-emitting components of the display device according to the pulse width modulation signal using a driver of the display device.

[0004] In an embodiment, the dimming method of the display device further includes the following steps: determining whether the number of multiple pulses of the pulse width modulation signal within a frame time is greater than 2. N The number of pulses to be modulated in each subframe time is an integer multiple of the number of bits in the color data. If not, the following steps are not performed; if yes, the following steps are performed: the frame time is divided into multiple subframe times according to the number of bits in the color data; and the number of multiple pulses to be modulated in each subframe time is determined according to the bit value of the color data.

[0005] In an embodiment, the dimming method of the display device further includes the following steps: extending the dithering time of each pulse to be modulated in the pulse width modulation signal.

[0006] In an embodiment, the dimming method of the display device further includes the following steps: determining which of the multiple pulses of the pulse width modulation signal to modulate based on the bit value of the color dithering data and the timing of the occurrence of multiple pulses of the pulse width modulation signal.

[0007] In an embodiment, the dimming method of the display device further includes the following steps: determining one or more pulses that appear consecutively among a plurality of pulses of the modulation pulse width modulation signal.

[0008] In an embodiment, the dimming method of the display device further includes the following steps: modulating multiple pulses in the next subframe time according to the modulation of multiple pulses in the previous subframe time.

[0009] As described above, the present invention provides a dimming method for a display device, which modulates the pulse width of a pulse width modulation signal to enable the display device to display images of different gray levels without increasing the internal frequency required by the processor.

[0010] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0011] Figure 1 This is a flowchart illustrating the steps of a dimming method for a display device according to an embodiment of the present invention.

[0012] Figure 2 This is a signal waveform diagram of the dimming method of the display device according to an embodiment of the present invention.

[0013] Figure 3 This is a signal waveform diagram of the dimming method of the display device according to an embodiment of the present invention.

[0014] Figure 4 This is a schematic diagram showing the number of bits in the data of the dimming method of the display device according to an embodiment of the present invention.

[0015] Figure 5 This is a signal waveform diagram of the dimming method of the display device according to an embodiment of the present invention.

[0016] Figure 6 This is a signal waveform diagram of the dimming method of the display device according to an embodiment of the present invention. Detailed Implementation

[0017] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. In addition, the term "or" as used herein may, depending on the actual situation, include any combination of any one or more of the associated listed items.

[0018] Please see Figures 1 to 6 ,in Figure 1 This is a flowchart illustrating the steps of a dimming method for a display device according to an embodiment of the present invention. Figure 2 , Figure 3 , Figure 5 and Figure 6 This is a signal waveform diagram of the dimming method of the display device according to an embodiment of the present invention; Figure 4 This is a schematic diagram showing the number of bits in the data of the dimming method of the display device according to an embodiment of the present invention.

[0019] The dimming method of the display device in this embodiment of the invention may include, for example: Figure 1 The steps S101~S111 are shown.

[0020] In step S101, a synchronization signal is generated, and each period of this synchronization signal is one frame time, such as, but not limited to, as shown in the example. Figure 2 The synchronization signal SYNC is shown as the nth frame time Tfn.

[0021] If necessary, the following steps can be performed before step S105: determine whether the number of multiple pulses of the pulse width modulation signal within the frame time is greater than 2. N The number of pulses in the pulse width modulation signal within a frame time is greater than 2. This is an integer multiple of N, where N is the number of bits in the dithered color data. N The frame time is divided into multiple sub-frame times based on the number of bits in the dithered color data, where the number of pulses is an integer multiple of the number of pulses in the frame time. Conversely, if the number of pulses in the pulse width modulation signal within the frame time is no greater than 2... N If the time is an integer multiple of the time, then the frame time is not segmented.

[0022] For example, such as Figure 4 The dithered data D2 shown is 4 bits. 4 =16. In this case, determine if... Figure 2Within the frame time Tfn, the number of pulses in the pulse width modulation signal PWM1 is determined to be greater than 16. If the frame time Tfn is 2.0833ms (frequency 480Hz), this frame time Tfn is divided by the period Tx of each pulse, "43.40208us", to calculate that the number of pulses within each frame time Tfn is 48. Next, the number of pulses "48" within each frame time Tfn is divided by "16" to determine that the number of sub-frame times Ts0, Ts1, and Ts2 divided from the frame time Tfn is 3, and there are at least 16 pulses in each sub-frame time Ts0, Ts1, and Ts2.

[0023] If a 10-bit display device is used, the frequency of the synchronization signal SYNC itself, for example, "480HZ", is multiplied by the number of pulses in each frame time Tfn, for example, "48", and then multiplied by 2^10 to calculate that the processor's internal frequency only needs to be 23.59296MHz.

[0024] In step S103, the bit value of the color data can be determined based on a target brightness data. This target brightness data indicates the image brightness that the display device intends to display.

[0025] In step S105, the number of multiple pulses that need to be modulated within the frame time in the pulse width modulation signal is determined based on the bit value of the dithering data.

[0026] In step S107, based on the bit value of the dithering data and the timing of the occurrence of multiple pulses of the pulse width modulation signal, it is determined which one or more of the multiple pulses of the pulse width modulation signal are being modulated. In this embodiment, it is determined to be one or more pulses that occur consecutively among the multiple pulses of the pulse width modulation signal, for example, one or more that occur first among the multiple pulses of the pulse width modulation signal, but the present invention is not limited thereto.

[0027] In step S109, the pulse width of the modulation signal is adjusted by adjusting the width of one or more of the multiple pulses.

[0028] In step S111, the driver of the display device modulates the pulse width modulation signal to the multiple light-emitting diodes of the backlight circuit according to the modulated pulse width modulation signal, so as to drive the multiple light-emitting diodes of the backlight circuit of the display device.

[0029] For ease of explanation, in this embodiment, the number of bits for the dithered color data D2 is, for example, 4 bits, but the present invention is not limited thereto. Figure 5As shown, if the number of bits in the dithered color data D2 is 4 bits, the bit value of the dithered color data D2 can be "0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110" or "1111".

[0030] like Figure 5 As shown, when the bit value of the dithered data D2 is "0000", the width of any pulse of the non-modulated pulse width modulated signal is the duty cycle of the non-modulated pulse. In this case, each of the multiple pulses of the modulated pulse width modulated signal has the same basic width.

[0031] like Figure 5 As shown, when the bit value of the dithered color data D2 is "0001", the pulse width modulation (PWM) signal modulates the width of one pulse (within each subframe time), that is, modulates the duty cycle of one pulse. For example, increasing the width of the earliest pulse in the PWM signal extends the duty cycle of this pulse and shortens its non-duty cycle, but does not modulate the total period of this pulse.

[0032] like Figure 5 As shown, when the bit value of the dithered color data D2 is "0010", the width of the two pulses in the pulse width modulation signal (within each subframe time) is increased, that is, the duty cycle of the two pulses is changed. For example, the width of the two earliest pulses in the pulse width modulation signal is increased, that is, the duty cycle of these two pulses is extended and the non-duty cycle of these two pulses is shortened, but the total period of the pulses is not changed.

[0033] like Figure 5 As shown, when the bit value of the dithered data D2 is "0011", the width of the three pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the three pulses is changed. For example, the width of the three pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0034] like Figure 5 As shown, when the bit value of the dithered color data D2 is "0100", the width of the four pulses of the pulse width modulation signal (within each subframe time) is increased, that is, the duty cycle of the four pulses is changed. For example, the width of the four pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0035] like Figure 5 As shown, when the bit value of the dithered data D2 is "0101", the width of the five pulses of the pulse width modulation signal (within each subframe time) is increased, that is, the duty cycle of the five pulses is changed. For example, the width of the five pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0036] like Figure 5 As shown, when the bit value of the dithered data D2 is "0110", the width of the six pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the six pulses is changed. For example, the width of the six pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0037] like Figure 5 As shown, when the bit value of the dithered color data D2 is "0111", the width of the seven pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the seven pulses is changed. For example, the width of the seven pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0038] like Figure 5 As shown, when the bit value of the dithered color data D2 is "1000", the width of the eight pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the eight pulses is changed. For example, the width of the eight pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0039] like Figure 5 As shown, when the bit value of the dithered color data D2 is "1001", the width of the nine pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the nine pulses is changed. For example, the width of the nine pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0040] like Figure 5As shown, when the bit value of the dithered color data D2 is "1010", the width of the ten pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the ten pulses is changed. For example, the width of the ten pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0041] like Figure 5 As shown, when the bit value of the dithered color data D2 is "1011", the width of the eleven pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the eleven pulses is changed. For example, the width of the eleven pulses (the earliest ones to appear) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0042] like Figure 5 As shown, when the bit value of the dithered color data D2 is "1100", the width of the twelve pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the twelve pulses is changed. For example, the width of the twelve pulses (the earliest ones) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0043] like Figure 5 As shown, when the bit value of the dithered color data D2 is "1101", the width of the thirteen pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the thirteen pulses is changed. For example, the width of the thirteen earliest appearing pulses in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended and the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0044] like Figure 5 As shown, when the bit value of the dithered color data D2 is "1110", the width of the fourteen pulses (within each subframe time) of the pulse width modulation signal is increased, that is, the duty cycle of the fourteen pulses is changed. For example, the width of the fourteen pulses (the earliest appearing) in the pulse width modulation signal is increased, that is, the duty cycle of these pulses is extended, the non-duty cycle of these pulses is shortened, but the total period of the pulses is not changed.

[0045] like Figure 5As shown, when the bit value of the dithered color data D2 is "1111", the pulse width modulation modulates the width of the fifteen pulses (within each subframe time) of the signal, that is, modulates the duty cycle of the fifteen pulses. For example, increasing the width of these fifteen pulses extends the duty cycle of these pulses and shortens the non-duty cycle of these pulses, but does not modulate the total period of the pulses.

[0046] like Figure 5 As shown, the width of each of the modulated pulses is greater than the basic width of the unmodulated pulse, and the widths of the modulated pulses are the same as each other, that is, the working periods of the modulated pulses are the same as each other, but the present invention is not limited thereto.

[0047] In practice, a dithering time can be calculated by dividing each cycle of the pulse width modulation (PWM) signal by the resolution data value. Then, based on this dithering time, the width of one or more pulses in the PWM signal is modulated. In other words, the duty cycle of the pulse to be modulated in the PWM signal can be extended by a dithering time.

[0048] Specifically, such as Figure 2 The period of each pulse of the pulse width modulation signal PWM2 shown is as follows: Figure 3 The data is represented by Tx. The resolution data has N bits. Calculate 2... N The value of is used as the numerical value of the resolution data. Next, the period Tx of each pulse of the pulse width modulation signal PWM2 is divided by the numerical value of the resolution data, i.e., 2... N The value is used to calculate the time of a color shake.

[0049] For example, such as Figure 4 As shown, when the resolution data D1 has 10 bits and the period Tx of each pulse of the pulse width modulation signal PWM2 is 2048ms, the value of 2^10 is calculated to be 1024. Then, 2048ms is divided by 1024ms to calculate the dithering time as 2ms. Next, the working period of each pulse to be modulated in the pulse width modulation signal PWM2 is extended by 2ms.

[0050] like Figure 6 As shown, the modulation of the pulse in the previous subframe time Ts0 can be the same as the modulation of the pulse in the next subframe time Ts1. That is, multiple pulses in the next subframe time Ts1 can be modulated based on the modulation of multiple pulses in the previous subframe time Ts0.

[0051] In summary, the present invention provides a dimming method for a display device, which modulates the pulse width of a pulse width modulation signal to enable the display device to display images of different gray levels without increasing the internal frequency required by the processor.

[0052] The above-disclosed content is only a preferred embodiment of the present invention and is not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included in the claims of the present invention.

Claims

1. A dimming method for a display device, applicable to a display device, characterized in that, The dimming method of the display device includes the following steps: A synchronization signal is generated, wherein each period of the synchronization signal is one frame time; The bit value of a dithering color data is determined based on the brightness data of a target. Determine whether the number of multiple pulses of a pulse width modulation signal within the frame time is greater than 2. N The number of bits in the color data is an integer multiple of the number of bits in the color data. If not, the frame time is not divided into multiple sub-frame times. If so, the frame time is divided into multiple sub-frame times according to the number of bits in the color data. Based on the bit value of the dithered color data, the number of pulses to be modulated in each subframe time of the frame time is determined, thereby modulating the width of one or more of the multiple pulses of the pulse width modulation signal; as well as A driver of the display device drives one or more of the plurality of light-emitting components of the display device according to the pulse width modulation signal.

2. The dimming method for a display device according to claim 1, characterized in that, The dimming method for the display device further includes the following steps: Based on the modulation of the plurality of pulses in the previous subframe time, the plurality of pulses in the next subframe time are modulated.

3. The dimming method for a display device according to claim 1, characterized in that, The dimming method for the display device further includes the following steps: Divide the period of the pulse width modulation signal by the value of the resolution data to calculate the color jitter time; and Based on the dithering time, the width of one or more of the pulses in the pulse width modulation signal is modulated.

4. The dimming method for a display device according to claim 3, characterized in that, The dimming method for the display device further includes the following steps: The working period of each pulse to be modulated in the pulse width modulation signal is extended by extending the dithering time.

5. The dimming method for a display device according to claim 1, characterized in that, The dimming method for the display device further includes the following steps: Based on the bit value of the color data and the timing of the occurrence of the multiple pulses of the pulse width modulation signal, it is determined which of the multiple pulses of the pulse width modulation signal will be modulated.

6. The dimming method for a display device according to claim 1, characterized in that, The dimming method for the display device further includes the following steps: The decision is made to modulate one or more pulses that occur consecutively among the plurality of pulses of the pulse width modulation signal.

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