TWI745038B - Pulse-width modulation dimming method with unequal difference - Google Patents

Abstract

A pulse-width modulation (PWM) dimming method with unequal difference applied between a transmitter and a receiver is disclosed. The PWM dimming method includes following steps: when the transmitter receives lights with different brightness ratios, the transmitter performs mapping to send PWM signals with different high-low voltage level ratios; and when the receiver receives the PWM signals with different high-low voltage level ratios, the receiver performs remapping to respectively emit the lights with different brightness ratios; wherein, the corresponding relationship between the high-low voltage level ratios and the different brightness ratios is presented as a polyline.

Description

Asymmetric pulse width modulation dimming method

The present invention is related to pulse-width modulation (PWM) technology, and in particular to an unequal difference (unequal difference) pulse-width modulation dimming method.

In the prior art, an equal difference (Equal difference) pulse width modulation dimming method is usually used between the transmitter (TX) and the receiver (RX).

For example, as shown in FIG. 1A, when the transmitting end TX receives the first light L1 with a brightness ratio of 75%, the second light L2 with a brightness ratio of 25%, and the third light L3 with a brightness ratio of 50%, the transmitting end TX Correspondingly send out the first pulse width modulation signal PWM1 with a high-low potential ratio of 75%, the second pulse-width modulation signal PWM2 with a high-low potential ratio of 25%, and the third pulse-width modulation signal PWM3 with a high-low potential ratio of 50% to receive At the end RX, the receiving end RX correspondingly emits a first light L1 with a brightness ratio of 75%, a second light L2 with a brightness ratio of 25%, and a third light L3 with a brightness ratio of 50%. The correspondence relationship between the high-low potential ratio and the brightness ratio of the lights presents a straight line equal difference (Equal difference) correspondence relationship, as shown in FIG. 1B.

However, because the noise of the system (such as the OSC jitter of the transmitting end TX/receiving end RX) is different in each level of brightness, the high-low potential ratio of the pulse width modulation signals and the light The straight line arithmetic correspondence between the brightness ratios may cause the maximum resolution of the system to be limited by the maximum noise, which needs to be improved urgently.

In view of this, the present invention proposes an unequal pulse width modulation dimming method to effectively solve the above-mentioned problems encountered in the prior art.

A specific embodiment according to the present invention is an unequal pulse width modulation dimming method. In this embodiment, the unequal pulse width modulation dimming method is applied between the transmitting end and the receiving end and includes the following steps: when the transmitting end receives a plurality of lights with different brightness ratios, the transmitting end performs Mapping, to respectively send out pulse width modulation signals with different high and low potential ratios; and when the receiving end receives the pulse width modulation signals with different high and low potential ratios, the receiving end performs re-mapping to respectively phase Correspondingly, the lights with different brightness ratios are emitted; wherein the corresponding relationship between the different high-low potential ratios and the different brightness ratios is presented as a broken line.

In one embodiment, the broken line includes at least a first line segment and a second line segment, and the first line segment and the second line segment intersect each other and each have a different slope.

In one embodiment, the first line segment and the second line segment intersect each other at a first intersection point, and the first intersection point corresponds to the first high-low potential ratio and the first brightness ratio.

In one embodiment, the ratio of the first high-low potential ratio to the first brightness ratio is less than 1, and the first slope of the first line segment is smaller than the second slope of the second line segment.

In one embodiment, the ratio of the first high-low potential ratio to the first brightness ratio is greater than 1, and the first slope of the first line segment is greater than the second slope of the second line segment.

In one embodiment, the transmitting end is mapped according to the correspondence between the different high-low potential ratios and the different brightness ratios.

In one embodiment, the receiving end performs re-mapping according to the correspondence between the different high-low potential ratios and the different brightness ratios.

In one embodiment, the transmitting end includes at least a mapping parameter (Mapping parameter) required for mapping.

In one embodiment, the receiving end includes at least one remapping parameter required for remapping.

In one embodiment, the polyline includes a first line segment, a second line segment, and a third line segment, each having a different slope, the first line segment and the second line segment intersect each other, and the second line segment and the third line segment intersect each other.

In one embodiment, the first line segment and the second line segment intersect each other at a first intersection point and the second line segment and the third line segment intersect each other at a second intersection point, the first intersection point corresponds to the first high-low potential ratio and the first brightness ratio And the second intersection corresponds to the second high-low potential ratio and the second brightness ratio.

In one embodiment, the ratio of the first high-low potential ratio to the first brightness ratio is less than 1 and the ratio of the second high-low potential ratio to the second brightness ratio is less than 1, and the first slope of the first line segment is less than that of the second line segment. The second slope and the second slope of the second line segment are smaller than the third slope of the third line segment.

In one embodiment, if the ratio of the first high-low potential ratio to the first brightness ratio is greater than 1, and the ratio of the second high-low potential ratio to the second brightness ratio is greater than 1, the first slope of the first line segment is greater than that of the second line segment. The second slope and the second slope of the second line segment are greater than the third slope of the third line segment.

Compared with the prior art, in the unequal pulse width modulation dimming method of the present invention, the transmitting end/receiving end are respectively based on the high-low potential ratio of the pulse-width modulation signals and the light The corresponding relationship between the fold-line Unequal difference between the brightness ratios is mapped/remapping, so that the resolution of each level of brightness is similar, thereby improving the resolution of the maximum noise And further improve the maximum resolution of the system, so it can effectively solve the problem that the resolution in the prior art is limited by the maximum noise.

The advantages and spirit of the present invention can be further understood from the following detailed description of the invention and the accompanying drawings.

S10~S16: steps

TX: Transmitter

RX: receiving end

L1: First light

L2: second light

L3: Third Light

PWM1: The first pulse width modulation signal

PWM2: The second pulse width modulation signal

PWM3: The third pulse width modulation signal

PL1: The first polyline

PL2: Second broken line

SG1: the first line segment

SG2: second line segment

SG3: The third line segment

N1: the first node

N2: second intersection

MP: mapping parameter

RMP: Remapping parameters

The drawings of the present invention are described as follows: FIG. 1A is a schematic diagram showing the arithmetic pulse width modulation dimming method in the prior art applied between the transmitting end and the receiving end.

FIG. 1B is a schematic diagram showing a linear equal difference between the high and low potential ratios of the pulse width modulation signals and the brightness ratios of the lights in FIG. 1A.

FIG. 2 is a flowchart of a method of unequal pulse width modulation and dimming according to a preferred embodiment of the present invention.

FIG. 3A shows an embodiment in which the unequal pulse width modulation and dimming method of the present invention is applied between the transmitting end and the receiving end.

FIG. 3B is a schematic diagram showing a zigzag-shaped unequal difference corresponding relationship between the high-low potential ratio of the pulse width modulation signals and the brightness ratio of the light in FIG. 3A.

4A shows another embodiment of the unequal pulse width modulation dimming method of the present invention applied between the transmitting end and the receiving end.

FIG. 4B is a schematic diagram showing a zigzag-shaped unequal difference corresponding relationship between the high-low potential ratio of the pulse width modulation signals and the brightness ratio of the light in FIG. 4A.

FIG. 5 shows a schematic diagram of the transmitting end and the receiving end of the present invention including mapping parameters and remapping parameters, respectively.

Reference will now be made in detail to the exemplary embodiments of the present invention, and examples of the exemplary embodiments are illustrated in the accompanying drawings. Elements/components with the same or similar numbers used in the drawings and embodiments are used to represent the same or similar parts.

A specific embodiment according to the present invention is an unequal pulse width modulation dimming method. In this embodiment, the unequal pulse width modulation dimming method can be applied to the display device, and can be applied to the signal transmission between the transmitting end and the receiving end, but it is not limited to this.

Please refer to FIG. 2. FIG. 2 is a flowchart of the unequal pulse width modulation dimming method in this embodiment.

As shown in FIG. 2, the unequal pulse width modulation dimming method in this embodiment may include the following steps: Step S10: The transmitting end receives a plurality of lights with different brightness ratios respectively; Step S12: The transmitting end performs a pairing Mapping to respectively send out pulse width modulation signals with different high and low potential ratios; step S14: the receiving end receives the pulse width modulation signals with different high and low potential ratios respectively; and step S16: the receiving end performs re- Remapping to emit the lights with different brightness ratios correspondingly.

It should be noted that there is an unequal difference between the high and low potential ratios of the pulse width modulation signals and the brightness ratios of the lights, for example, the relationship between the two The response curve is presented as a polyline, but it is not limited to this.

Therefore, in practical applications, the transmitting end can map according to the non-equal difference between the high and low potential ratios of the pulse width modulated signals and the brightness ratios of the lights, so as to perform the mapping according to the received Lights with different brightness ratios correspondingly output the pulse width modulation signals with different high and low potential ratios; in the same way, the receiving end can adjust the signal's high to low potential ratio and the brightness ratio of the lights according to the pulse width The unequal difference of the corresponding relationship is re-mapped, so that the light with different brightness ratios is correspondingly output according to the pulse width modulation signals with different high and low potential ratios.

Next, please refer to FIG. 3A and FIG. 3B. FIG. 3A shows an embodiment in which the unequal pulse width modulation and dimming method of the present invention is applied between the transmitting end and the receiving end. FIG. 3B is a schematic diagram showing the corresponding relationship between the high-low potential ratio of the pulse width modulation signals and the brightness ratio of the light in FIG. 3A with a broken line-shaped unequal difference.

As shown in FIG. 3A, when the transmitting end TX receives the first light L1 with a brightness ratio of 75%, the second light L2 with a brightness ratio of 25%, and the third light L3 with a brightness ratio of 50% (that is, the step in FIG. 2 S10), the transmitting end TX will map according to the unequal difference corresponding to the broken line shown in FIG. 3B, and correspondingly send out the first pulse width modulation signal PWM1 with a high-low potential ratio of 50%, and a high-low potential ratio 12.5% of the second pulse width modulation signal PWM2 and the third pulse width modulation signal PWM3 with a high-low potential ratio of 25% (that is, step S12 in FIG. 2).

When the receiving end RX receives the first pulse width modulation signal PWM1 with a high-low potential ratio of 50%, the second pulse width modulation signal PWM2 with a high-low potential ratio of 12.5%, and the third pulse-width modulation signal PWM3 with a high-low potential ratio of 25% When (that is, step S14 in Figure 2), the receiving end RX will perform remapping (Remapping) according to the broken line-shaped unequal correspondence relationship shown in Figure 3B to correspond to the first light with a brightness ratio of 75%. L1, the second light with a brightness ratio of 25%, L2, and the third light with a brightness ratio of 50% L3 (that is, step S16 in FIG. 2).

As shown in FIG. 3B, in this embodiment, the corresponding relationship curve between the high-low potential ratios of the pulse width modulation signals PWM1~PWM3 and the brightness ratios of the lights L1~L3 is shown as a first broken line PL1, and The first broken line PL1 includes a first line segment SG1 and a second line segment SG2, and the first line segment SG1 and the second line segment SG2 intersect each other and have different slopes respectively.

In detail, the first line segment SG1 and the second line segment SG2 intersect each other at the first intersection point N1, and the first intersection point N1 corresponds to the first high-low potential ratio (that is, 50%) and the first brightness ratio (that is, 75%). %). It can also be seen from FIG. 3B that the ratio (that is, 0.67) of the first high-low potential ratio (that is, 50%) and the first brightness ratio (that is, 75%) in this embodiment is less than 1. Therefore, the first line The first slope of the segment SG1 is smaller than the second slope of the second line segment SG2.

By analogy, in another embodiment, if the ratio of the first high-low potential ratio corresponding to the first intersection N1 to the first brightness ratio is greater than 1, the first slope of the first line segment SG1 is greater than that of the second line segment SG2 The second slope, but not limited to this.

Next, please refer to FIG. 4A and FIG. 4B. 4A shows another embodiment of the unequal pulse width modulation dimming method of the present invention applied between the transmitting end and the receiving end. FIG. 4B is a schematic diagram showing a zigzag-shaped unequal difference corresponding relationship between the high-low potential ratio of the pulse width modulation signals and the brightness ratio of the light in FIG. 4A.

As shown in FIG. 4A, when the transmitting end TX receives the first light L1 with a brightness ratio of 75%, the second light L2 with a brightness ratio of 25%, and the third light L3 with a brightness ratio of 50% (that is, the step in FIG. 2 S10). The transmitting end TX will map according to the unequal difference corresponding to the broken line as shown in Fig. 4B to correspondingly send out the first pulse width modulation signal PWM1 with a high-low potential ratio of 62.5%. 12.5% of the second pulse width modulation signal PWM2 and the third of the high-low potential ratio of 37.5% The pulse width modulation signal PWM3 (that is, step S12 in FIG. 2).

When the receiving end RX receives the first pulse width modulation signal PWM1 with a high-low potential ratio of 62.5%, the second pulse width modulation signal PWM2 with a high-low potential ratio of 12.5%, and the third pulse-width modulation signal PWM3 with a high-low potential ratio of 37.5% When (that is, step S14 in FIG. 2), the receiving end RX will perform remapping (Remapping) according to the broken line-shaped non-equal difference corresponding relationship shown in FIG. 4B to correspondingly emit the first light with a brightness ratio of 75% L1, the second light L2 with a brightness ratio of 25%, and the third light L3 with a brightness ratio of 50% (that is, step S16 in FIG. 2).

As shown in FIG. 4B, in this embodiment, the corresponding relationship curve between the high-low potential ratios of the pulse width modulation signals PWM1~PWM3 and the brightness ratios of the lights L1~L3 is presented as a second broken line PL2, and The second broken line PL2 includes a first line segment SG1, a second line segment SG2, and a third line segment SG3. The first line segment SG1, the second line segment SG2, and the third line segment SG3 have different slopes. The first line segment SG1 and the second line segment SG3 have different slopes. The line segment SG2 intersects each other and the second line segment SG2 and the third line segment SG3 intersect each other.

In detail, the first line segment SG1 and the second line segment SG2 intersect each other at a first intersection point N1, and the second line segment SG2 and the third line segment SG3 intersect each other at a second intersection point N2, and the first intersection point N1 corresponds to the first high-low potential ratio. (That is, 12.5%) and the first brightness ratio (that is, 25%) and the second intersection point N2 corresponds to the second high-low potential ratio (that is, 62.5%) and the second brightness ratio (that is, 75%).

It can also be seen from FIG. 4B that the ratio of the first high-low potential ratio (that is 12.5%) to the first brightness ratio (that is, 25%) (that is, 0.5) is less than 1 and the second high-low potential ratio in this embodiment (That is, 62.5%) and the second brightness ratio (that is, 75%) ratio (that is, 0.83) is also less than 1, therefore, the first slope of the first line segment SG1 is smaller than the second slope of the second line segment SG2 and the first The second slope of the second line segment SG2 is smaller than the third slope of the third line segment SG3.

By analogy, in another embodiment, if the ratio of the first high-low potential ratio corresponding to the first intersection N1 to the first brightness ratio is greater than 1, and the second high-low potential ratio corresponding to the second intersection N2 and the second brightness If the ratio of the ratio is greater than 1, the first slope of the first line segment SG1 is greater than the second slope of the second line segment SG2 and the second slope of the second line segment SG2 is greater than the third slope of the third line segment SG3, but not limited to this .

In practical applications, as shown in FIG. 5, the transmitting end TX of the present invention may include at least a mapping parameter (Mapping parameter) MP required for mapping, which is used for mapping; the receiving end RX It may include at least a remapping parameter (Remapping parameter) RMP required for remapping, but it is not limited to this.

Compared with the prior art, in the unequal pulse width modulation dimming method of the present invention, the transmitting end/receiving end are respectively based on the difference between the high and low potential ratio of the pulse width modulation signals and the brightness ratio of the lights Unequal difference (Unequal difference) correspondence relationship for mapping (Mapping) / re-mapping (Remapping), so that the resolution of each level of brightness is similar, so as to improve the resolution of the maximum noise and thereby improve the maximum resolution of the system Therefore, it can effectively solve the problem that the resolution in the prior art is limited by the maximum noise.

S10~S16: steps

Claims (13)

An unequal pulse width modulation dimming method, applied between a transmitting end and a receiving end, includes the following steps: when the transmitting end receives a plurality of lights with different brightness ratios, the transmitting end performs a Mapping to respectively send out pulse width modulation signals with different high and low potential ratios; and when the receiving end receives the pulse width modulation signals with different high and low potential ratios, the receiving end performs repeated pairing Remapping, to respectively correspondingly emit the lights with different brightness ratios; wherein, the different high-low potential ratios and the different brightness ratios have a zigzag-shaped unequal difference correspondence relationship. The pulse width modulation dimming method described in claim 1, wherein the broken line includes at least a first line segment and a second line segment, the first line segment and the second line segment intersect each other and have different slopes respectively . The pulse width modulation dimming method described in the scope of patent application 2, wherein the first line segment and the second line segment intersect each other at a first intersection point, and the first intersection point corresponds to a first high-low potential ratio and A first brightness ratio. The pulse width modulation dimming method described in item 3 of the scope of patent application, wherein the ratio of the first high-low potential ratio to the first brightness ratio is less than 1, and a first slope of the first line segment is less than the second A second slope of the line segment. The pulse width modulation dimming method described in item 3 of the scope of patent application, wherein the ratio of the first high-low potential ratio to the first brightness ratio is greater than 1, and a first slope of the first line segment is greater than the second A second slope of the line segment. For the pulse width modulation dimming method described in item 1 of the scope of patent application, the transmitting end performs the mapping according to the corresponding relationship between the different high-low potential ratios and the different brightness ratios. According to the pulse width modulation dimming method described in item 1 of the scope of patent application, the receiving end performs the re-mapping according to the corresponding relationship between the different high-low potential ratios and the different brightness ratios. According to the pulse width modulation dimming method described in item 1 of the scope of the patent application, the transmitting end includes at least a mapping parameter (Mapping parameter) required for the mapping. According to the pulse width modulation dimming method described in item 1 of the scope of patent application, the receiving end includes at least one remapping parameter required for performing the remapping. For example, the pulse width modulation dimming method described in claim 1, wherein the broken line includes a first line segment, a second line segment, and a third line segment, each having a different slope, the first line segment and the first line segment The two line segments intersect each other and the second line segment and the third line segment intersect each other. The pulse width modulation dimming method described in claim 10, wherein the first line segment and the second line segment intersect each other at a first intersection point, and the second line segment and the third line segment intersect each other at a first intersection point. Two intersections, the first intersection corresponds to a first high-low potential ratio and a first brightness ratio, and the second intersection corresponds to a second high-low potential ratio and a second brightness ratio. The pulse width modulation dimming method described in claim 11, wherein the ratio of the first high-low potential ratio to the first brightness ratio is less than 1, and the second high-low potential ratio is compared with the second brightness ratio. If the ratio of the brightness ratio is less than 1, then a first slope of the first line segment is less than a second slope of the second line segment and the second slope of the second line segment is less than a third slope of the third line segment. The pulse width modulation dimming method described in claim 11, wherein the ratio of the first high-low potential ratio to the first brightness ratio is greater than 1, and the ratio of the second high-low potential ratio to the second brightness ratio is greater than 1, then a first slope of the first line segment is greater than a second slope of the second line segment and the second slope of the second line segment is greater than a third slope of the third line segment.

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