CN107765497B - Light emitting device, projection system, and image modulation method - Google Patents

Abstract

A light-emitting device capable of emitting light of a first color, the period during which the light-emitting device emits light of the first color includes at least a first sub-time period and a second sub-time period, and the light-emitting device is in the first sub-time period The light intensity of the first color light emitted in the second sub-time period is different from that of the light intensity of the first color light emitted in the second sub-time period. The invention also provides a projection system and an image modulation method.

Description

Light emitting device, projection system and image modulation method

technical field

The invention relates to the field of projection technology, in particular to a light emitting device, a projection system and an image modulation method.

Background technique

Existing projection systems generally include a light emitting device, a light valve and a control device. The light emitting device emits three colors of light, red, green and blue. The control device acquires input image data and controls the light valve to receive the three colors of light and An image is modulated according to input image data. However, the light-emitting device often suffers from insufficient light of a certain color (such as insufficient red light) due to poor phosphor efficiency and aging, resulting in poor brightness of a certain color picture, which affects the projection picture effect of the projection system.

Contents of the invention

In order to solve the technical problem of poor projected picture effect of the prior art projection system, it is necessary to provide a light emitting device, a projection system and an image modulation method applied to the projection system that can solve the above problems.

A light-emitting device capable of emitting light of a first color, the period during which the light-emitting device emits light of the first color includes at least a first sub-time period and a second sub-time period, and the light-emitting device is in the first sub-time period The light intensity of the first color light emitted in the second sub-time period is different from that of the light intensity of the first color light emitted in the second sub-time period.

Further, the light emitting device includes:

a light source for emitting light;

The wavelength conversion device is arranged in the transmission path of the light emitted by the light source, and the wavelength conversion device can periodically emit light of different colors in time sequence under the irradiation of the light source. It is assumed that the wavelength conversion device moves for one cycle The duration is one cycle of the wavelength conversion device. In one cycle of the wavelength conversion device, the period during which the wavelength conversion device emits light of the first color includes at least a first sub-time period and a second sub-time period. The light intensity of the first color light emitted in the first sub-time period and the second sub-time period is different.

Further, the light emitting device further includes a light source driving module for driving the light source, and the value of the first current used by the light source driving module for driving the light source in the first sub-time period is set to be the second A current value; the value of the second current used by the light source driving module to drive the light source in the second sub-time period is a second current value, and the first current value and the second current value Are not the same.

Further, at least one of the first current value and the second current value is a fixed value.

Further, at least one of the first current value and the second current value changes with time.

Further, the light intensity of the first color light emitted by the wavelength conversion device in the first sub-time period is greater than the light intensity of the first color light emitted in the second sub-time period, and the first sub-time period occurs before the second sub-time period.

Further, the first color is red, and the first color light is red light.

A projection system, comprising the above-mentioned light emitting device, a control device, and a light valve, the control device is capable of acquiring input image data, and within each frame image display period of the input image data, the light valve is The first color of the image is image-modulated during the period when the light-emitting device emits light of the first color.

Further, the time for the light valve to modulate the first color includes the first color on-state time and the first color off-state time, the input image data includes the input grayscale value of the first color, and the first color on-state time The state time corresponds to the grayscale value of the first color input.

Further, when the grayscale value of the first color input is 1, the first color open state time of the light valve is t, and when the grayscale value of the first color input is Hx, the first color of the light valve is The color-on state time is Hx×t, where Hx is an integer greater than or equal to 0 and less than or equal to 255;

Assuming that the first color input grayscale value is Hn, the light valve modulates the first color input grayscale value Hn for the first color on-state time Hn×t equal to the first sub-time period, when the When Hx is less than or equal to Hn, the first color input grayscale value Hx is modulated by the light valve to use the first color light emitted by the light emitting device in the first sub-time period as a light source; when the Hx When it is greater than the Hn, the first n gray scales of the Hx are modulated by the first color light emitted in the first sub-time period as a light source, and the latter (x-n) gray scales of the Hx pass through the light The valve modulates the light of the first color emitted by the light emitting device in the second sub-time period as a light source.

Further, for a certain pixel in the image, the relative relationship curve between the preset output light intensity of the pixel and the actual output light intensity of the pixel includes at least two segments, and in each segment, the preset output light intensity of the pixel Let the output light intensity be linearly related to the actual output light intensity of the pixel, or

The relative relationship curve formed between the preset output light intensity of the pixel and the actual output light intensity of the pixel is a monotonically increasing continuous curve.

An image modulation method applied to a projection system, where a light emitting device of the projection system can generate light of a first color, the image modulation method comprising:

Acquire a frame of input image data signal, generate a first color light modulation signal according to the input image data signal, the first color light modulation signal corresponds to the first color grayscale image data, and the first color grayscale image data includes the first color grayscale image data Input the grayscale value of the first color of each pixel for a color;

Inputting the first color light modulation signal to the light valve of the projection system, the light valve performs image modulation on the corresponding light emitted by the light emitting device of the projection system according to the first color light modulation signal, and the light emission The period during which the device emits light of the first color includes at least a first sub-time period and a second sub-time period, and the light of the first color light emitted by the light-emitting device during the first sub-time period and the second sub-time period Strongly different.

Further, the light modulation signal of the first color is input to the light valve of the projection system, and the light valve performs image modulation on the corresponding light emitted by the light emitting device of the projection system according to the light modulation signal of the first color. The step further includes: inputting the light modulation signal of the first color to the light valve of the projection system, and when the light valve performs image modulation on the corresponding light emitted by the light emitting device of the projection system according to the modulation signal, further includes Detecting the light emitted by the light-emitting device of the projection system, and generating a synchronization signal, inputting the synchronization signal and the light modulation signal to the light valve so that the modulation signal of the light valve is consistent with the corresponding light emitted by the light-emitting device Synchronize.

Further, the light intensity of the first color light emitted by the light emitting device in the first sub-time period is greater than the light intensity of the first color light emitted in the second sub-time period, and the first sub-time period Occurs before said second sub-time period.

An image modulation method applied to a projection system, the light-emitting device of the projection system can emit a first color light with two different light intensities of the first color light, the image modulation method includes:

Acquire a frame of input image data signal, generate a first color light modulation signal according to the input image data signal, the first color light modulation signal corresponds to the first color grayscale image data, and the first color grayscale image data includes the first color grayscale image data Input the grayscale value of the first color of each pixel for a color;

Comparing the input grayscale value of a certain pixel with a preset grayscale value, if the input grayscale value of the first color is smaller than the preset grayscale value, the light emitting device emits When the first color light emits light with a higher light intensity of the first color light, if the input grayscale value of the first color is greater than or equal to the preset grayscale value, the light emitting device emits the first color light emit light with a lower light intensity of the first color;

Input the light modulation signal of the first color to the light valve of the projection system, and control the light emitting device to emit the first color light according to the corresponding light intensity of the first color light according to the comparison result, and the light valve according to the first The color light modulation signal performs image modulation on the first color light emitted by the light emitting device of the projection system.

Compared with the prior art, the light emitting device, the projection system and the image modulation method applied to the projection system of the present invention, because the light emitting device can emit the first color light with different light intensities, by controlling the light valve to perform the first color light according to the input image data One-color image modulation can combine the low-grayscale first color picture with the sub-region with strong light intensity to achieve the purpose of increasing the brightness of the low-grayscale first color picture, so that the brightness of the first color picture is higher. The projection screen displayed by the projection system is better.

Description of drawings

Fig. 1 is a projection system provided by a preferred embodiment of the present invention.

Fig. 2 is a plan view showing the structure of the wavelength conversion device.

FIG. 3 is a timing diagram of the light valve and the wavelength conversion device of the present invention.

FIG. 4 is a relative relationship curve between the preset output light intensity of a pixel of the output image and the actual output light intensity of the first color of the pixel according to an embodiment of the present invention.

Fig. 5 is a relative relationship curve between the preset output light intensity of a pixel of the output image and the actual output light intensity of the first color of the pixel according to another embodiment of the present invention.

FIG. 6 is a flowchart of an image modulation method applied to a projection system provided by the present invention.

FIG. 7 is a flow chart of another image modulation method applied to a projection system provided by the present invention.

Description of main component symbols

Projection System 100

Lighting device 10

light source 11

Wavelength Converter 13

Light source driver module 14

Wavelength conversion device drive module 15

First Color Area 131

First sub-area 1311

Second sub-area 1313

Second color field 133

Tertiary color field 135

Homogenizer 16

light valve 20

Controls 30

projection lens 50

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

It should be noted that, in the present invention, when a component is considered to be "connected" to another component, it may be directly connected to another component, or may be indirectly connected to another component through an intermediate component.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

Referring to FIG. 1 , a preferred embodiment of the present invention provides a projection system 100 , which includes a light emitting device 10 , a light valve 20 and a control device 30 . The light emitting device 10 can emit light of different colors in time sequence. The light valve 20 is located in the transmission path of the light emitted by the light emitting device 10 and used for image modulation of the light emitted by the light emitting device 10 . The control device 30 is used to control the operation of other functional modules of the projection system 100 such as the light emitting device 10 and the light valve 20 .

The light emitting device 10 includes a light source 11 and a wavelength converting device 13 . The light source 11 is used to emit light; the wavelength conversion device 13 is used to receive the light emitted by the light source 11 and emit light of different colors in time sequence.

The light source 11 may be a conventional lamp, or a solid state light source including a laser or a light emitting diode (LED). For solid state light sources, the wavelength of the light typically ranges from 300nm to 500nm. For example, many LED manufacturers produce light-emitting diodes (so-called blue LEDs) that emit light at 460nm. A major advantage of solid-state light sources over conventional light bulbs, including mercury lamps, is their ability to be modulated. Both lasers and LEDs can be modulated at frequencies above 1Mhz. In this embodiment, the light source 11 emits blue excitation light.

Please refer to FIG. 2 , which is a schematic plan view of the wavelength conversion device 13 . In this embodiment, the wavelength conversion device 13 is approximately a circular color wheel, which includes a first color region 131, a second color region 133 and a third color region 135 arranged along its circular motion direction, respectively used to receive the light source 11 and emit the first color light, the second color light and the third color light. The first color area 131 includes a first sub-area 1311 and a second sub-area 1313 . The first sub-region 1311 , the second sub-region 1313 , the second color region 133 , and the third color region 135 are sequentially arranged along the circumferential direction. The first color area 131 is a red area, the second color area 133 is a green area, and the third color area 135 is a blue area. The first color light is red light, the second color light is green light, and the third color light is blue light.

In this embodiment, the wavelength conversion device 13 is a transmissive wavelength conversion device, that is, the light from the light source 11 enters the wavelength conversion device 13 from one side, and emits light of at least two colors from the other side of the wavelength conversion device 13 . Preferably, at least one region (such as 131, 133, 135) on the wavelength conversion device 13 carries a wavelength conversion material, and the wavelength conversion material irradiated by the light source 11 on the wavelength conversion device 13 is absorbed to perform wavelength conversion to produce other The wavelength conversion device 13 emits light of different colors.

Specifically, in one embodiment, the first color region 131 of the wavelength conversion device 13 is provided with a first color fluorescent material (such as a first color phosphor), and the second color region 133 is provided with a second color fluorescent material ( Like the second color phosphor), the third color area 135 is a transmission area. Please refer to FIG. 3 , which is a timing diagram of light emission when the light emitting device 10 of the present invention is in operation. Specifically, FIG. 3 is a timing diagram of light emission of light of various colors emitted by the light source 11 through the wavelength conversion device 13 . When the light-emitting device 10 is working, the wavelength conversion device 13 rotates continuously around the center of its circumference, so that the first color region 131, the second color region 133 and the third color region 135 receive the light emitted from the light source 11 in sequence, and then The light of the first color, the light of the second color and the light of the third color are sequentially emitted. It can be understood that when the light source 11 is an ultraviolet laser light source, the third color region 135 carries a third color fluorescent material, and the third color fluorescent material is a third color phosphor powder. In the third color area 135, the phosphor powder of the third color is excited to emit light of the third color. The wavelength conversion materials in the first color, second color, and third color regions preferably emit light in the wavelength ranges of 580nm to 700nm, 500nm to 580nm, and 400nm to 500nm, respectively.

In this embodiment, the structure, shape, size, material composition, density, etc. of the first subregion 1311 and the second subregion 1313 are the same, that is, the first color region 131 does not really include two subregions, but only For the convenience of subsequent description.

The shapes and sizes of the first color region 131 , the second color region 133 and the third color region 135 on the wavelength conversion device 13 are the same. It can be understood that the shapes and sizes of the first color region 131 , the second color region 133 and the third color region 135 may be different. The region of the wavelength conversion device 13 that receives the excitation light changes continuously, such as from red to green to blue region, resulting in emitting light of different colors. The rate of color change of the emitted light is directly related to the rotational speed of the wavelength conversion device 13 .

It can be understood that, in another embodiment, the wavelength conversion device 13 may be a strip structure, or a cylindrical structure capable of periodic rotation, which can emit light of different colors periodically and in time sequence.

The light source driving module 14 is used to drive the light source 11 , and the light intensity of the light emitted by the wavelength conversion device 13 can be changed by controlling the current value of the driving light source 11 . In this embodiment, it is assumed that the length of time for the wavelength conversion device 13 to rotate one revolution is a wavelength conversion device cycle, and within a wavelength conversion device cycle, the period during which the wavelength conversion device 13 emits light of the first color includes at least the first sub-time period and Second sub-period. Assuming that in the first sub-time period, the light source driving module 14 drives the light source 11 to irradiate the first color area 131 to emit the first color light R1, the current value is the first current value I1; in the second sub-time period, the light source The driving module 14 drives the light source 11 to irradiate the first color area 131 to emit the first color light R2. The light intensity of the first color light emitted in the first sub-time period and the second sub-time period is different. Let the light emitted by the wavelength conversion device 13 in the first sub-time period be the first color light R1, and let the light emitted by the wavelength conversion device 13 in the second sub-time period be the first color light R2. The light intensity of the first color light R1 and the first color light R2 are different. The time period during which the first sub-region 1311 emits the first color light R1 is the first sub-time period, and the time period during which the second sub-region 1313 emits the first color light R2 is the second sub-time period.

The wavelength conversion device driving module 15 is used to drive the wavelength conversion device 13 to rotate.

Further, the light emitting device 10 further includes a dodging device 16 for dodging the light emitted from the wavelength converting device 13 .

The light valve 20 is located in the transmission path of the light emitted by the wavelength conversion device 13 . The light emitted from the wavelength conversion device 13 can enter the light valve 20 . The first color light, the second color light, and the third color light modulated by the light valve 20 project a pre-display image. It can be understood that the light valve 20 can be LCD, LCoS, DMD and so on. Preferably, the light valve is selected as DMD.

The control device 30 is connected to the light source driving module 14 so that the light source light of a predetermined wavelength band required for image generation can be emitted from the light emitting device 10 . The control device 30 is connected with the wavelength conversion device driving module 15 and is used for controlling the rotation speed of the wavelength conversion device 13 and the like. The control device 30 is used to receive input image data, and can generate a first color light modulation signal to enable the light valve 20 to modulate according to the first color light when the light emitting device 10 emits the first color light R1 and the first color light R2 The signal performs first color image modulation; the control device 30 can generate a second color light modulation signal according to the input image data to control the light valve 20 to modulate according to the second color light during the period when the light emitting device 10 emits the second color light The signal is modulated by the second color image; the control device 30 can generate a third color light modulation signal according to the input image data so that the light valve 20 can be modulated according to the third color light during the period when the light emitting device 10 emits the third color light The signal undergoes image modulation of the third color. The input image data includes input grayscale values of the first color, the second color, and the third color at each pixel.

In this embodiment, one frame of image display period corresponds to the modulation period of one frame of output image, and one frame of image display period also corresponds to one wavelength conversion device period. In each frame of image display period of the input image data, the light valve 20 performing image modulation on the first color of the image during the period when the light emitting device 10 emits light of the first color.

In this implementation manner, the first sub-time period occurs before the second sub-time period.

Please refer to FIG. 3 , during the period during which the light valve 20 modulates a frame of output image, the light valve 20 includes the first color on-state time (such as the ON time period) and the first color off-state time (such as the OFF time period), The one frame of input image data includes first color grayscale data, and the first color grayscale data includes the first color input grayscale value of each pixel point, and the first color input grayscale value set at a certain pixel point is Hx, the first color open state time of the light valve 20 for the corresponding pixel corresponds to the first color input gray scale value. For example, when the grayscale value of the first color input is grayscale 1, the first color open state time of the light valve 20 is t, and when the grayscale value of the first color input is Hx, the light The first color open state time of the valve 20 is Hx×t, where Hx can be any integer greater than or equal to 0 and less than or equal to 255 (ie the maximum gray scale value Hm).

In this embodiment, regardless of the input grayscale value of the first color, the start point of the first color open state time of the light valve 20 is the same as the start point of the first sub-time period, that is, the first When a sub-region 1311 starts to emit the first color light R1, the light valve 20 starts to enter the first color open state time, so as to perform image modulation according to the first color input gray scale value.

For example, assuming that the first color input grayscale value of a certain pixel of a certain frame of input image data is Hn, the first color open state time of the light valve 20 is Hn×t, and the first color open state time Hn×t is equal to the first sub-time period, when the first color input grayscale value Hx of a certain pixel is less than or equal to Hn, the corresponding first color open state time Hx×t of the light valve 20 is less than or equal to Hn×t, the first sub-time period is fixed, and the starting point of the first color-on state time of the light valve 20 is the same as the starting point of the first sub-time period, so in the corresponding The input grayscale values Hx of the first color of the pixels are all modulated by the first color light R1 in the first sub-time period as the light source. Since the intensity of the first color light R1 is relatively high, the input image data The smaller grayscale value Hx can be modulated by light with higher intensity as a light source, so that the region with a lower grayscale in the input data can obtain higher brightness.

Further, when the first color input grayscale value Hx is greater than Hn, the first color open state time Hx×t corresponding to the light valve 20 is greater than Hn×t, so the first n segments of the first color input grayscale value Hx All the gray scales are modulated by the light valve 20 using the first color light R1 emitted by the wavelength conversion device 13 in the first sub-time period as a light source, and the (x-n) gray scales in the latter stage are modulated by the light valve 20 The first color light R2 emitted by the wavelength conversion device 13 in the second sub-time period is modulated as a light source. Since the intensity of the first color light R2 is relatively low, when the light valve 20 modulates a relatively large input gray scale value Hx, it does not use the relatively high intensity first color light R1 as the light source, but partially uses the low intensity light R1 as the light source. The intensity of the first color light R2 is modulated as a light source.

According to the above analysis, as shown in FIG. 4 , in one embodiment, the light source driving module 14 controls the first current value I1 and the second current value I2 to be fixed values. For a certain pixel in the output image, the The relative relationship curve between the preset output light intensity of the first color of the pixel and the actual output light intensity of the first color of the pixel includes two segments, and in each segment, the preset output light of the first color of the pixel The intensity varies linearly with the actual output light intensity of the first color of the pixel. The first current value I1 is greater than the second current value I2, so that the light intensity of the first color light R1 emitted in the first sub-time period is greater than the light intensity of the first color light R2 emitted in the second sub-time period . For the input grayscale value of the first color when the input image data is less than or equal to Hn, the light valve 20 uses the first color light R1 emitted by the wavelength conversion device 13 in the first sub-time period as a light source for modulation, and the pixel point The slope of the line segment (K1) formed by the preset output light intensity of the first color of the pixel and the actual output light intensity of the first color of the pixel is relatively large; for the input grayscale value of the first color in the input image data greater than Hn, the light valve 20 using the first color light R1 emitted by the wavelength conversion device 13 in the first sub-time period and the first color light R2 emitted in the second sub-time period as light sources for modulation. Since the light intensity of the first color light R2 is smaller than the light intensity of the first color light R1, the line segment (K2 ) has a smaller slope than K1.

It can be understood that when the number of sub-time periods is greater than two, that is, the driving current of the light source driving module 15 in multiple sub-time periods is a fixed value and is not the same, then the preset output of the first color of the pixel The relative relationship curve between the light intensity and the actual output light intensity of the first color of the pixel is composed of multiple segmented line segments. In each segment, the preset output light intensity of the first color of the pixel is related to the pixel’s first color The line segment formed by the actual output light intensity of a color changes linearly.

For example, if the input grayscale value Hn of the first color is 128, and the input grayscale value Hx of the first color at a certain pixel is 100, when the light valve 20 performs image modulation, at the corresponding pixel, the input grayscale value of the first color All the order values 100 are modulated by the first color light R1 emitted by the wavelength conversion device 13 in the first sub-time period as a light source. For another example, suppose Hn is 128, and the input grayscale value Hx of the first color at a certain pixel point is 128. When the light valve 20 performs image modulation, at the corresponding pixel point, the input grayscale value of the first color is all 128 by the specified pixel. The wavelength conversion device 13 modulates the first color light R1 in the first sub-time period as a light source. For another example, Hn is 128, the first color input grayscale value Hx at a certain pixel point is 200, when the light valve 20 performs image modulation, at the corresponding pixel point, the first color input grayscale value Hx is 128 in the front section of 200 The gray scale is modulated by the first color light R1 emitted by the wavelength conversion device 13 in the first sub-time period as a light source (that is, the first 128 gray scales are modulated by the first color light R1 emitted by the first sub-region 1311 as a light source modulated), the last 72 gray scales are modulated by the first color light R2 in the second sub-time period (that is, the last 72 gray scales are modulated by the first color light R2 emitted from the second sub-region 1313 as a light source).

Further, the composition, density, and area of fluorescent materials in the first sub-region 1311 and the second sub-region 1313 are the same, and the current for driving the light source 11 is controlled by the light source driving module 14, so that the first sub-region The optical density of the first color light R1 emitted from the region 1311 is three times that of the second sub-region 1313 . For example, in the input image data, when the intensity of the first color light in a certain area is preset as S, the intensity of the emitted first color light is S. In the input image data, when the preset light intensity of the first color in a certain area is 0.5, the emitted light intensity of the first color is 0.75S.

It can be understood that at least one of the first current value I1 and the second current value I2 is a fixed value.

It can be understood that at least one of the first current value I1 and the second current value I2 changes with time.

Further, the projection system 100 further includes a projection lens 50 for projecting and displaying the image modulated by the light valve 20 .

In another embodiment, the first current value I1 changes with time in the first sub-time period, and the second current value I2 changes with time in the second sub-time period, so as to avoid The chromatic aberration drastically changes in the boundary area between the sub-region 1311 and the second sub-region 1313 , which causes uncomfortable visual experience when viewing. Please refer to FIG. 5 , the relative relationship curve between the preset output light intensity of the first color of a certain pixel in the output image and the actual output light intensity of the first color of the pixel is a monotonically increasing curve.

Set the formula of the outgoing light intensity-image light intensity curve as:

y=f(x),

Suppose the formula of the "gray scale-visual intensity curve" of the human eye for the first color light is:

Y=F(y),

but,

Y=F(f(x)),

Among them, x is the grayscale value of the color light, and Y is the brightness perceived by the human eye, so that the brightness seen by the human eye is linearly related to the image brightness, and there will be no problem with the brightness resolution of the human eye when the image brightness is low. Chromatic aberration problems caused by low.

It can be understood that the light emitting device 10 can omit the light source driving module 14, and the driving control can be performed by setting the light source driving module on the control device 30; the light emitting device 10 can omit the wavelength conversion device driving module 15. Perform drive control by setting a wavelength conversion device drive module in the control device 30 .

It can be understood that, in an embodiment, the wavelength conversion device 13 may be configured as a reflection type.

It can be understood that the number of sub-regions of the first color region 131 is not limited to two sub-regions, it may be three or more, that is, the number of sub-time periods may be three or more.

It can be understood that it is not limited to the period of emitting the first color light including at least two sub-time periods, the period of emitting the second color light may also include at least two sub-time periods, and the period of emitting the third color light may also include at least two sub-times part.

It can be understood that the first color area of the wavelength conversion device 13 includes at least a first sub-area and a second sub-area, and the phosphor material or density of the first sub-area is different from that of the phosphor in the second sub-area. The material or density is such that under the same excitation light, the light intensity of the first color light emitted by the first sub-region is different from the light intensity of the first color light emitted by the second photon region.

It can be understood that it is not limited to the fact that the first sub-time period occurs before the second sub-time period, that is, if the first sub-time period occurs after the second sub-time period, then the wavelength conversion device 13 emits The order of the color lights is the first color light R2, the first color light R1, the third color light, the second color light, the first color light R2....

It can be understood that the starting point of the first color-on state time may be different from the starting point of the first sub-time period.

It can be understood that the phosphor material or density of the first sub-region 1311 is different from that of the phosphor material or density of the second sub-region 1313, so that under the illumination of the light source 11, the light intensity of the first color light emitted by the first sub-region 1311 The light intensity of the first color light emitted by the second sub-region 1313 is different. In this embodiment, the density of the phosphor powder in the first sub-region 1311 is three times that of the phosphor powder in the second sub-region 1313 . The phosphor density of the first sub-region 1311 and the second sub-region 1313 is uniform. Let the first color light emitted by the first sub-region 1311 be the first color light R1, and let the first color light emitted by the second sub-region 1313 be the first color light R2.

It can be understood that the phosphor density on the first sub-region 1311 and the second sub-region 1313 of the wavelength conversion device 13 of the projection system 100 both varies.

The present invention also provides an image modulation method applied to the above projection system, please refer to FIG. 6 , the light emitting device of the projection system can generate light of the first color, and the image modulation method includes:

Step 601, acquire a frame of input image data signal, generate a first color light modulation signal according to the input image data signal, the first color light modulation signal corresponds to the first color grayscale image data, and the first color grayscale image The data includes an input grayscale value of the first color at each pixel point of the first color.

Step 602, input the light modulation signal of the first color to the light valve of the projection system, and the light valve performs image modulation on the corresponding light emitted by the light emitting device of the projection system according to the light modulation signal of the first color, The period during which the light-emitting device emits light of the first color includes at least a first sub-time period and a second sub-time period, and the first color emitted by the light-emitting device during the first sub-time period and the second sub-time period The intensity of light varies.

In this embodiment, the light modulation signal of the first color is input to the light valve of the projection system, and when the light valve performs image modulation on the corresponding light emitted by the light emitting device of the projection system according to the modulation signal, it also It includes detecting the light emitted by the light emitting device of the projection system and generating a synchronous signal, and inputting the synchronous signal and the light modulation signal to the light valve so that the modulation signal of the light valve is corresponding to that emitted by the light emitting device light sync.

In the period during which one frame of output image is modulated, the light valve includes a first color on-state time (such as an ON time period) and a first color off-state time (such as an OFF time period), and the one frame of input image data The input grayscale value of the first color at a certain pixel point is Hx, and the on-state time of the first color at the corresponding pixel point corresponds to the input grayscale value of the first color. For example, when the grayscale value of the first color input is grayscale 1, the first color open state time of the light valve 20 is t, and when the grayscale value of the first color input is Hx, the light The first color open state time of the valve 20 is Hx×t, where Hx can be any integer greater than or equal to 0 and less than or equal to 255 (ie the maximum gray scale value Hm).

In this embodiment, no matter what the input grayscale value of the first color is, the start point of the first color open state time of the light valve is the same as the start point of the first sub-time period, that is, the light emitting device When the first color light R1 starts to be emitted, the light valve starts to enter the first color open state time, so as to perform image modulation according to the first color input gray scale value.

For example, assuming that the first color input grayscale value of a certain pixel of a certain frame of input image data is Hn, the first color open state time of the light valve is Hn×t, and the first color open state time Hn ×t is equal to the first sub-time period, when the first color input grayscale value Hx of a certain pixel is less than or equal to Hn, the first color open state time corresponding to the light valve Hx×t is less than or equal to Hn×t, the first sub-time period is fixed, and the starting point of the first color-on state time of the light valve is the same as the starting point of the first sub-time period, so at the corresponding pixel The input grayscale value Hx of the first color is all modulated by the first color light R1 in the first sub-time period. Since the intensity of the first color light R1 is relatively high, the grayscale value Hx in the input image data is relatively small. Hx can be modulated by light of higher intensity, so that a region with a lower gray scale in the input data can obtain higher brightness.

Further, when the first color input grayscale value Hx is greater than Hn, the first color open state time Hx×t corresponding to the light valve is greater than Hn×t, so the first segment n of the first color input grayscale value Hx The first color light R1 emitted by the wavelength conversion device in the first sub-time period is modulated by the light valve as a light source, and the (x-n) gray levels in the latter stage are modulated by the light valve. The first color light R2 emitted by the wavelength conversion device in the second sub-time period is modulated as a light source. Since the intensity of the first color light R2 is relatively low, for a larger input gray scale value Hx of the first color, when the light valve performs modulation, it does not use the higher intensity first color light R1 as the light source, but Partially use the lower intensity first color light R2 as the light source for modulation.

In another embodiment, the present invention further provides an image modulation method applied to a projection system, the light emitting device of the projection system can emit the first color light with two different light intensities of the first color light, please refer to the figure 7. The image modulation method includes:

Step 701, acquire a frame of input image data signal, generate a first color light modulation signal according to the input image data signal, the first color light modulation signal corresponds to the first color grayscale image data, and the first color grayscale image The data includes an input grayscale value of the first color at each pixel point of the first color.

Step 702, comparing the input grayscale value of the first color of a certain pixel with a preset grayscale value. If the input grayscale value of the first color is smaller than the preset grayscale value, make the light emitting device emit light with a higher light intensity of the first color when emitting light of the first color; if the first color When the input gray scale value is greater than or equal to the preset gray scale value, the light emitting device is made to emit light with a lower light intensity of the first color light when emitting the first color light. In this embodiment, the preset grayscale value is pre-stored in the control device of the projection system, and the preset grayscale value is 128, so that the light valve of the projection system modulates the lower value at the first Use a brighter light as the light source when entering values for a color.

Step 703, input the first color light modulation signal to the light valve of the projection system, and according to the comparison result, control the light emitting device to emit the first color light according to the corresponding light intensity of the first color light, and the light valve The first color light emitted by the light emitting device of the projection system is image modulated according to the first color light modulation signal. In this implementation manner, the actual light intensity value of the first color light is increased by adjusting and increasing the driving current of the light source that drives the light emitting device.

Compared with the prior art, the wavelength conversion device 13 provided by the present invention, the light emitting device 10 using the wavelength conversion device 13, the projection system 100 and the image modulation method applied to the projection system 100, the light emitting device 10 emits the first The color light period includes at least two sub-time periods, and the intensity of the first color light emitted by the two sub-time periods is different. By controlling the light valve 20 to perform first color image modulation according to the input image data, the low-grayscale The first color picture cooperates with stronger light to achieve the purpose of increasing the brightness of the low gray scale first color picture, so that the brightness of the first color picture is higher, so that the projection system 100 displays a better projection picture effect.

It can be understood that those skilled in the art can also make other changes within the spirit of the present invention to be used in the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims (14)

1. A projection system, comprising:

the light emitting device can emit first color light, the period of emitting the first color light by the light emitting device at least comprises a first sub-period and a second sub-period, and the light intensity of the first color light emitted by the light emitting device in the first sub-period is different from that in the second sub-period;

A control device capable of acquiring input image data including a first color input gray scale value;

a light valve for image-modulating a first color of the image during a period in which the light emitting device emits the first color light in each frame image display period of the input image data,

wherein, for the input image data having a lower first color input gray scale value, the light valve modulates with the first color light of which the light emitting device emits a stronger light intensity in the first sub-period and the second sub-period as a light source.

2. The projection system of claim 1, wherein: the light emitting device includes:

a light source for emitting light;

the wavelength conversion device is arranged in a transmission path of light emitted by the light source, the wavelength conversion device can periodically emit light with different colors according to time sequence under the irradiation of the light source, the movement period of the wavelength conversion device is set to be one wavelength conversion device period, the period of emitting the first color light by the wavelength conversion device in one wavelength conversion device period at least comprises a first sub-period and a second sub-period, and the light intensity of the first color light emitted by the wavelength conversion device in the first sub-period is different from that of the light intensity of the first color light emitted by the wavelength conversion device in the second sub-period.

3. The projection system of claim 2, wherein: the light-emitting device further comprises a light source driving module for driving the light source, wherein the value of a first current for driving the light source is a first current value, and the first current value is set in the first sub-time period; the second current value of the light source driving module set in the second sub-time period for driving the light source is a second current value, and the first current value is different from the second current value.

4. A projection system according to claim 3, wherein: at least one of the first current value and the second current value is a fixed value.

5. A projection system according to claim 3, wherein: at least one of the first current value and the second current value is time-varying.

6. The projection system of claim 2, wherein: the light intensity of the first color light emitted by the wavelength conversion device in the first sub-period is larger than the light intensity of the first color light emitted by the wavelength conversion device in the second sub-period, and the first sub-period occurs before the second sub-period.

7. The projection system of any of claims 1-6, wherein: the first color is red, and the first color light is red.

8. The projection system of claim 1, wherein: the time for modulating the first color by the light valve comprises first color on-state time and first color off-state time, and the first color on-state time corresponds to the first color input gray scale value.

9. The projection system of claim 8, wherein: when the first color input gray scale value is set to be 1, the first color on state time of the light valve is set to be t, and when the first color input gray scale value is set to be Hx, the first color on state time of the light valve is set to be Hx multiplied by t, wherein Hx is an integer which is more than or equal to 0 and less than or equal to 255;

when the first color input gray scale value is set to be Hn, the first color on state time Hn multiplied by t of the first color input gray scale value Hn modulated by the light valve is equal to the first sub-time period, and when Hx is smaller than or equal to Hn, the first color input gray scale value Hx modulates first color light emitted by the light emitting device in the first sub-time period as a light source through the light valve; when the Hx is larger than the Hn, the n gray scales of the front section of the Hx are modulated by the first color light emitted by the first sub-time period as a light source, and the (x-n) gray scales of the rear section of the Hx are modulated by the light valve by the first color light emitted by the light emitting device in the second sub-time period as a light source.

10. The projection system of claim 8, wherein: for a certain pixel point in the first color image, the relative relation curve formed by the preset output light intensity of the pixel point and the actual output light intensity of the pixel comprises at least two segments, wherein in each segment, the preset output light intensity of the pixel and the actual output light intensity of the pixel are in linear relation, or

The relative relation curve formed by the preset output light intensity of the pixel point and the actual output light intensity of the pixel is a continuous curve which monotonically increases.

11. An image modulation method applied to a projection system, a light emitting device of the projection system capable of generating a first color light, the image modulation method comprising:

acquiring a frame of input image data signal, and generating a first color light modulation signal according to the input image data signal, wherein the first color light modulation signal corresponds to first color gray scale image data, and the first color gray scale image data comprises first color input gray scale values of a first color at each pixel point;

the first color light modulation signal is input to a light valve of the projection system, the light valve carries out image modulation on corresponding light emitted by a light emitting device of the projection system according to the first color light modulation signal, a period of emitting the first color light by the light emitting device at least comprises a first sub-period and a second sub-period, the light intensity of the first color light emitted by the light emitting device in the first sub-period is different from that of the first color light emitted by the light emitting device in the second sub-period, aiming at the input image data with lower first color input gray scale value, the light valve carries out modulation by taking the first color light with stronger light intensity emitted by the light emitting device in the first sub-period and the second sub-period as a light source.

12. The image modulation method of claim 11, wherein: the step of inputting the first color light modulation signal to a light valve of the projection system, wherein the light valve performs image modulation on corresponding light emitted by a light emitting device of the projection system according to the first color light modulation signal, further comprises: the first color light modulation signal is input to a light valve of the projection system, and when the light valve carries out image modulation on corresponding light emitted by a light emitting device of the projection system according to the modulation signal, the method further comprises detecting the light emitted by the light emitting device of the projection system, generating a synchronization signal, and inputting the synchronization signal and the light modulation signal to the light valve so that the modulation signal of the light valve is synchronous with the corresponding light emitted by the light emitting device.

13. The image modulation method of claim 11, wherein: the light intensity of the first color light emitted by the light emitting device in the first sub-period is larger than the light intensity of the first color light emitted by the light emitting device in the second sub-period, and the first sub-period occurs before the second sub-period.

14. An image modulation method applied to a projection system, a light emitting device of which is capable of emitting light of a first color at two different light intensities of the light of the first color, the image modulation method comprising:

Acquiring a frame of input image data signal, and generating a first color light modulation signal according to the input image data signal, wherein the first color light modulation signal corresponds to first color gray scale image data, and the first color gray scale image data comprises first color input gray scale values of a first color at each pixel point;

comparing a first color input gray level value of a pixel point with a preset gray level value, if the first color input gray level value is smaller than the preset gray level value, enabling the light-emitting device to emit light with higher first color light intensity when emitting first color light, and if the first color input gray level value is larger than or equal to the preset gray level value, enabling the light-emitting device to emit light with lower first color light intensity when emitting first color light;

the first color light modulation signal is input to a light valve of the projection system, the light emitting device is controlled to emit first color light according to the corresponding first color light intensity according to the comparison result, and the light valve carries out image modulation on the first color light emitted by the light emitting device of the projection system according to the first color light modulation signal.