CN114900673A

CN114900673A - Method and device for correcting color cast of projection picture, projection equipment and storage medium

Info

Publication number: CN114900673A
Application number: CN202210384002.XA
Authority: CN
Inventors: 张金武; 全晓荣; 张聪; 胡震宇
Original assignee: Shenzhen Huole Science and Technology Development Co Ltd
Current assignee: Shenzhen Huole Science and Technology Development Co Ltd
Priority date: 2022-04-12
Filing date: 2022-04-12
Publication date: 2022-08-12
Anticipated expiration: 2042-04-12
Also published as: CN114900673B

Abstract

The disclosure relates to a method and a device for correcting color cast of a projection picture, a projection device and a storage medium. The method comprises the following steps: in response to the detection that the projection equipment is started, controlling the light source part and the spatial light modulator to work, and controlling the heat dissipation assembly to work at a first heat dissipation power; if the current temperature of the spatial light modulator reaches the preset steady-state temperature, controlling the heat dissipation assembly to work at a second heat dissipation power; and when the current temperature reaches the preset steady-state temperature, carrying out gamma correction on the projection picture. Therefore, the heat dissipation assembly can dissipate heat of the spatial light modulator at a low heat dissipation rate, the temperature of the spatial light modulator rises rapidly to a preset stable temperature, a projection picture is recovered rapidly to be normal, and the impression experience of a user is improved. In addition, the temperature of the spatial light modulator is stabilized at the preset stable temperature through the heat dissipation assembly, so that the color cast of the projection picture is stable, and the projection picture can be ensured to be stably cast by the projection equipment by performing gamma correction on the projection picture once when the current temperature reaches the preset stable temperature.

Description

Method and device for correcting color cast of projection picture, projection equipment and storage medium

Technical Field

The present disclosure relates to the field of projection devices, and in particular, to a method and an apparatus for correcting color cast of a projection image, a projection device, and a storage medium.

Background

A projection apparatus generally includes a light source section, a spatial light modulator, and a heat dissipation member for dissipating heat from the spatial light modulator. The temperature control of the spatial light modulator is crucial, and directly affects the quality of the picture. When the temperature of the spatial light modulator is high, a projection picture can generate color cast, and the color cast correction method at the present stage can completely correct the color cast after ten minutes or even half an hour after the projection equipment is started, so that the viewing experience of a user is influenced.

Disclosure of Invention

The disclosure discloses a color cast correction method and device for a projection picture, projection equipment and a storage medium, which are used for shortening the time of color cast of the projection picture so as to improve the impression experience of a user.

In a first aspect, the present disclosure relates to a color cast correction method for a projection screen, which is applied to a projection apparatus including a light source unit, a spatial light modulator, and a heat dissipation component for dissipating heat from the spatial light modulator, the method including:

in response to the detection that the projection equipment is started, controlling the light source part and the spatial light modulator to work, and controlling the heat dissipation assembly to work at a first heat dissipation power to acquire the current temperature of the spatial light modulator;

if the current temperature reaches a preset steady-state temperature, controlling the heat dissipation assembly to work at a second heat dissipation power so as to stabilize the current temperature at the preset steady-state temperature, wherein when the preset steady-state temperature is reached, a projection picture of the projection equipment has global color cast, and the second heat dissipation power is greater than the first heat dissipation power;

and when the current temperature reaches the preset steady-state temperature, carrying out gamma correction on the projection picture so as to realize color cast correction of the projection picture.

Optionally, the method further comprises:

and before the current temperature reaches the preset steady-state temperature, carrying out gamma correction on the projection picture according to a preset time period.

Optionally, the gamma correcting the projection picture includes:

determining first target gamma correction data of the projection picture at the current temperature;

and carrying out gamma correction on the projection picture according to the first target gamma correction data.

Optionally, the projection screen includes a plurality of tile screens;

the gamma correcting the projection picture comprises the following steps:

and respectively carrying out gamma correction on each block picture.

Optionally, the performing γ correction on each of the block pictures respectively includes:

determining a second target gamma correction data of each block picture at the current temperature; and carrying out gamma correction on the block picture according to the second target gamma correction data.

Optionally, the projection apparatus further comprises a heating assembly for heating the spatial light modulator;

the method further comprises the following steps:

controlling the heating assembly to work in response to detecting that the projection device is started;

and if the current temperature reaches the preset steady-state temperature, controlling the heating assembly to stop working.

Optionally, the heat dissipation assembly and the heating assembly are integrated into a semiconductor refrigerator;

the control the heat dissipation assembly to work with a second heat dissipation power includes:

applying a first voltage in a first direction to two ends of the semiconductor refrigerator so that the semiconductor refrigerator works at a second heat dissipation power;

the controlling the heating assembly to operate comprises:

a second voltage in a second direction is applied across the semiconductor refrigerator to cause the semiconductor refrigerator to heat the spatial light modulator, wherein the second direction is opposite to the first direction.

In a second aspect, the present disclosure relates to a color cast correction device for a projection picture, applied to a projection apparatus including a light source section, a spatial light modulator, and a heat dissipation member for dissipating heat from the spatial light modulator, the device including:

the control module is used for controlling the light source part and the spatial light modulator to work in response to the detection that the projection equipment is started, controlling the heat dissipation assembly to work at a first heat dissipation power, and acquiring the current temperature of the spatial light modulator;

the control module is further configured to control the heat dissipation assembly to operate at a second heat dissipation power to stabilize the current temperature at a preset steady-state temperature if the current temperature reaches the preset steady-state temperature, wherein a projection picture of the projection device has global color cast at the preset steady-state temperature, and the second heat dissipation power is greater than the first heat dissipation power;

and the correction module is used for carrying out gamma correction on the projection picture when the current temperature reaches the preset steady-state temperature so as to realize color cast correction of the projection picture.

Optionally, the correction module is further configured to perform γ correction on the projection picture according to a preset time period before the current temperature reaches the preset steady-state temperature.

Optionally, the correction module comprises:

a first determining submodule, configured to determine first target γ correction data of the projection picture at the current temperature;

and the first correction submodule is used for carrying out gamma correction on the projection picture according to the first target gamma correction data.

Optionally, the projection screen includes a plurality of tile screens;

the correction module is used for respectively carrying out gamma correction on each block picture.

Optionally, the correction module comprises:

a second determining submodule, configured to determine, for each block picture, second target γ correction data of the block picture at the current temperature; and the second correction submodule is used for carrying out gamma correction on the block picture according to the second target gamma correction data.

the control module is further configured to:

the control module is used for:

applying a second voltage in a second direction to two ends of the semiconductor refrigerator to enable the semiconductor refrigerator to heat the spatial light modulator, wherein the second direction is opposite to the first direction.

In a third aspect, the present disclosure is directed to a projection device comprising:

a light source unit;

a spatial light modulator;

the heat dissipation assembly is used for dissipating heat of the spatial light modulator;

a memory having a computer program stored thereon;

a processor configured to execute the computer program in the memory to implement the steps of the method for correcting color cast of the projection picture provided by the first aspect of the present disclosure.

In a fourth aspect, the present disclosure relates to a computer-readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the steps of the method for color cast correction of a projection picture provided by the first aspect of the present disclosure.

The disclosure relates to a method and a device for correcting color cast of a projection picture, a projection device and a storage medium. When the method detects that the projection equipment is started, the light source part and the spatial light modulator are controlled to work, and meanwhile, the heat dissipation assembly used for dissipating heat of the spatial light modulator is controlled to work at the first heat dissipation power lower than the second heat dissipation power, so that the heat dissipation assembly can dissipate heat of the spatial light modulator at a low heat dissipation rate, the temperature of the spatial light modulator is rapidly increased to a preset steady-state temperature, and gamma correction is carried out on a projection picture of the projection equipment when the temperature of the spatial light modulator reaches the preset steady-state temperature. Therefore, the time from the starting of the projection equipment to the time when the temperature of the spatial light modulator reaches the preset steady-state temperature can be shortened, namely the time for color cast of the projection picture is shortened, so that the projection picture is quickly recovered to be normal, and the impression experience of a user is improved. In addition, after the temperature of the spatial light modulator rapidly rises to the preset stable temperature, the temperature of the spatial light modulator is stabilized at the preset stable temperature through the heat dissipation assembly, so that the color cast of the projection picture is stable, the projection picture can be ensured to be put into a stable and color cast-free projection picture by performing gamma correction on the projection picture once when the current temperature reaches the preset stable temperature, and the projection picture does not need to be subjected to repeated gamma correction subsequently.

Drawings

Fig. 1 is a flowchart illustrating a method of color cast correction of a projection screen according to an exemplary embodiment.

Fig. 2 is a flowchart illustrating a method of color cast correction of a projection screen according to another exemplary embodiment.

Fig. 3 is a flowchart illustrating a method of color cast correction of a projection screen according to another exemplary embodiment.

Fig. 4 is a block diagram illustrating a color cast correction apparatus for projecting a picture according to an exemplary embodiment.

FIG. 5 is a schematic diagram of a projection device in one embodiment.

Detailed Description

As discussed in the background, the temperature control of the spatial light modulator is critical and directly affects the picture-dropping quality. Specifically, when the spatial light modulator temperature reaches T1, the projection screen may have a local color cast, and when the spatial light modulator temperature reaches T2, the projection screen may have a global color cast, and T2 is greater than T1. For the color cast of the projection picture, the projection picture can be restored to normal by gamma correction. The local color cast means that a partial region of a projection picture is subjected to color cast, the global color cast means that the whole projection picture is subjected to color cast, and the color cast means that the current chromaticity coordinate of the corresponding region is not consistent with the expected chromaticity coordinate (namely, the target chromaticity coordinate).

At present, after the projection equipment is started, the light source part, the spatial light modulator and the heat dissipation assembly start to work simultaneously, and when the temperature of the spatial light modulator reaches T2, namely when the projection picture has global color cast, the projection picture is adjusted so as to restore the projection picture to normal. Therefore, the projection often can realize complete color cast correction after dozens of minutes or even half an hour after the projection device is started, and the appearance and experience of a user are influenced.

In view of the above, the present disclosure provides a method and an apparatus for correcting color cast of a projection image, a projection device, and a storage medium.

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather are provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the disclosure are for illustration purposes only and are not intended to limit the scope of the disclosure.

It should be understood that the various steps recited in the method embodiments of the present disclosure may be performed in a different order and/or performed in parallel. Moreover, method embodiments may include additional steps and/or omit performing the illustrated steps. The scope of the present disclosure is not limited in this respect.

The term "include" and variations thereof as used herein are open-ended, i.e., "including but not limited to". The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Relevant definitions for other terms will be given in the following description.

It should be noted that the terms "first", "second", and the like in the present disclosure are only used for distinguishing different devices, modules or units, and are not used for limiting the order or interdependence relationship of the functions performed by the devices, modules or units.

It is noted that references to "a", "an", and "the" modifications in this disclosure are intended to be illustrative rather than limiting, and that those skilled in the art will recognize that "one or more" may be used unless the context clearly dictates otherwise.

The names of messages or information exchanged between devices in the embodiments of the present disclosure are for illustrative purposes only, and are not intended to limit the scope of the messages or information.

Fig. 1 is a flowchart illustrating a method for color cast correction of a projection screen according to an exemplary embodiment, wherein the method may be applied to a projection apparatus. As shown in fig. 1, the method may include the following S101 to S103.

In S101, in response to detecting that the projection device is started, the light source part and the spatial light modulator are controlled to work, and the heat dissipation component is controlled to work at a first heat dissipation power, so that the current temperature of the spatial light modulator is obtained.

In the present disclosure, a projection apparatus includes a light source section, a spatial light modulator, and a heat dissipation member for dissipating heat of the spatial light modulator. The Light source unit may include a solid Light source such as a Light Emitting Diode (LED), a laser, and a pump lamp; the spatial light modulator is configured to modulate a light beam emitted by the light source according to image information of an image to be projected to obtain the image light to be projected, and the spatial light modulator may be, for example, a Digital micro-mirror Device (DMD), a Liquid Crystal Display panel (LCD), or a Liquid Crystal On Silicon (LCOS); the heat dissipation assembly may be an air cooling structure, a liquid cooling structure, a semiconductor Cooler (TEC), or a combination of at least two of the air cooling structure, the liquid cooling structure, and the TEC, for example, the air cooling structure + the TEC. The heat dissipation assembly may be directly mounted on the surface of the spatial light modulator, or a Thermal Interface Material (TIM) is disposed between the heat dissipation assembly and the spatial light modulator to reduce contact resistance and improve heat dissipation performance.

When the projection equipment is started, the light source part and the spatial light modulator are controlled to work, and meanwhile, the heat dissipation component used for dissipating heat of the spatial light modulator is controlled to work at a first heat dissipation power lower than a second heat dissipation power, namely, the heat dissipation component dissipates heat of the spatial light modulator at a lower heat dissipation rate. Therefore, the spatial light modulator is in a state of slow heat dissipation, and the temperature of the spatial light modulator rises faster compared with the situation that the heat dissipation assembly dissipates heat to the spatial light modulator with larger heat dissipation power.

Preferably, first heat dissipation power is zero, and heat dissipation assembly does not carry out the heat dissipation work promptly, and at this moment, spatial light modulator is in nature radiating state, and like this, spatial light modulator's temperature can rise to predetermineeing steady state temperature fast to shorten the length of time of projection picture colour cast, thereby make the projection picture resume normal more fast, promoted user's impression and experienced.

In addition, the temperature of the spatial light modulator can be acquired in real time by a temperature sensor.

In S102, if the current temperature reaches the preset steady-state temperature, the heat dissipation assembly is controlled to operate at the second heat dissipation power, so as to stabilize the current temperature at the preset steady-state temperature.

In the disclosure, when the steady-state temperature is preset, the projection picture of the projection device has global color cast; the second heat dissipation power is larger than the first heat dissipation power.

The inventor finds that after the projection device is started, the spatial light modulator works to cause the temperature of the spatial light modulator to continuously rise, and when the temperature of the spatial light modulator reaches T1, the projection picture has a local color cast condition, and when the temperature of the spatial light modulator reaches T2, the projection picture has a global color cast condition, wherein T2 is larger than T1. Specifically, when the spatial light modulator temperature is in the range of [0, T1), the projection screen has no color cast; when the temperature of the spatial light modulator is in the range of [ T1, T2 ], the projected picture has local color cast; when the spatial light modulator temperature is within the range of [ T2, ∞), the projection screen may be globally color-shifted. The preset steady-state temperature can be a preset temperature range, namely the heat dissipation assembly works with second heat dissipation power to enable the current temperature to be within the preset temperature range; the preset steady-state temperature may also be a preset temperature value, and at this time, the preset steady-state temperature may be greater than a critical temperature T2 at which the spatial light modulator has global color cast, or may be equal to T2, which is not specifically limited in this disclosure. Preferably, the preset steady-state temperature is equal to T2, which is set to facilitate reaching the preset steady-state temperature as quickly as possible, and to facilitate shortening of the time required for the color cast correction process.

If the current temperature of the spatial light modulator reaches the preset steady-state temperature, the current temperature of the spatial light modulator is continuously obtained; if the current temperature of the spatial light modulator reaches the preset steady-state temperature, the heat dissipation assembly can be controlled to work according to a preset temperature control strategy so as to stabilize the temperature of the spatial light modulator at the preset steady-state temperature, namely, the temperature of the spatial light modulator is maintained near the preset steady-state temperature. The preset temperature control strategy may be proportional-integral-derivative (PID) control, neural network control, fuzzy control, and the like, and the disclosure is not limited specifically.

In S103, when the current temperature reaches the preset steady-state temperature, γ correction is performed on the projection picture to implement color cast correction of the projection picture.

When the method detects that the projection equipment is started, the light source part and the spatial light modulator are controlled to work, and meanwhile, the heat dissipation assembly used for dissipating heat of the spatial light modulator is controlled to work at the first heat dissipation power lower than the second heat dissipation power, so that the heat dissipation assembly can dissipate heat of the spatial light modulator at a low heat dissipation rate, the temperature of the spatial light modulator is rapidly increased to the preset steady-state temperature, and when the temperature of the spatial light modulator reaches the preset steady-state temperature, gamma correction is carried out on a projection picture of the projection equipment. Therefore, the time from the starting of the projection equipment to the time when the temperature of the spatial light modulator reaches the preset steady-state temperature can be shortened, namely the time for color cast of the projection picture is shortened, so that the projection picture is quickly recovered to be normal, and the impression experience of a user is improved. In addition, after the temperature of the spatial light modulator rapidly rises to the preset stable temperature, the temperature of the spatial light modulator is stabilized at the preset stable temperature through the heat dissipation assembly, so that the color cast of the projection picture is stable, the projection picture can be ensured to be put into a stable and color cast-free projection picture by performing gamma correction on the projection picture once when the current temperature reaches the preset stable temperature, and the projection picture does not need to be subjected to repeated gamma correction subsequently.

A detailed description will be given below of a specific embodiment of performing gamma correction on the projection screen of the projection apparatus when the current temperature reaches the preset steady-state temperature in S103.

In this disclosure, after the spatial light modulator temperature rises rapidly to predetermine steady state temperature, stabilize spatial light modulator temperature at predetermine steady state temperature through radiator unit, can be so that the projection picture colour cast is stable, at this moment, only need carry out gamma correction once to the projection picture and can guarantee that projection equipment puts in out stable, the projection picture of no colour cast, follow-up need not to carry out gamma correction to the projection picture again repeatedly.

Fig. 2 is a flowchart illustrating a method of color cast correction of a projection screen according to another exemplary embodiment. As shown in fig. 2, before the above S103, the above method may further include the following S104.

In S104, before the current temperature of the spatial light modulator reaches the preset steady-state temperature, γ correction is performed on the projection picture according to a preset time period.

When the projection equipment is started until the temperature of the spatial light modulator reaches the preset steady-state temperature, the projection picture of the projection equipment is subjected to regular color cast correction, the putting quality of the picture in the period can be ensured, and the impression experience of a user is further improved.

The following describes in detail a specific embodiment of the gamma correction of the projection screen. In one embodiment, the projection picture may be subjected to global color cast correction, that is, the projection picture as a whole is subjected to color cast correction. Specifically, it can be realized by the following S1031 and S1032:

s1031: first target gamma correction data of the projection picture at the current temperature is determined.

Specifically, first γ correction data of the projection picture at different temperatures, that is, a corresponding relationship between the temperature and the first γ correction data of the projection picture, may be obtained first; then, the first gamma correction data corresponding to the current temperature, i.e. the first target gamma correction data of the projection picture at the current temperature, is determined according to the corresponding relationship between the temperature and the first gamma correction data of the projection picture.

In the present disclosure, the first gamma correction data of the projection screen at different temperatures may be previously constructed, and the first gamma correction data of the projection screen at different temperatures may be stored in the form of a table or a curve. The first gamma correction data includes R data, G data and B data. When the first gamma correction data of the projection picture at different temperatures are stored in a table form, the first gamma correction data corresponding to the current temperature, namely the first target gamma correction data, can be obtained through table lookup; when the first gamma correction data of the projection picture at different temperatures are stored in the form of a curve, the first gamma correction data corresponding to the current temperature, that is, the first target gamma correction data, may be acquired through the curve.

S1032: and carrying out gamma correction on the projection picture according to the first target gamma correction data.

Specifically, the projection device may be controlled to project a picture according to the first target γ correction data, where the projected picture is normal and has no color cast.

In another embodiment, to improve the accuracy of the color cast correction of the projection picture, the color cast correction of the projection picture of the projection apparatus may be performed by block, specifically, the projection picture includes a plurality of block pictures, and in this case, γ correction may be performed separately for each block picture. In one embodiment, the projection picture may be divided into m rows and n columns, i.e. the projection picture includes m × n block pictures, where m ≧ 1, n ≧ 1, and m + n ≧ 3. For example, m is 3, n is 3; for example, m is 1 and n is 6, and the present disclosure does not limit a specific layout manner of each block screen in the projection screen.

In one embodiment, the γ correction can be performed on each tile picture by the following S1033 and S1034:

s1033: for each block picture, second target gamma correction data of the block picture at the current temperature is determined.

Specifically, for each block frame, second γ correction data of the block frame at different temperatures, i.e. a corresponding relationship between the temperature and the second γ correction data of the block frame, can be obtained; then, according to the corresponding relationship between the temperature and the second gamma correction data of the block frame, the second gamma correction data of the block frame corresponding to the current temperature, that is, the second target gamma correction data of the block frame at the current temperature, is determined.

In the present disclosure, the second gamma correction data of each block picture at different temperatures may be pre-constructed, and may be stored in a table format, or stored in a curve format, i.e., one block picture corresponds to one curve. The second gamma correction data includes R data, G data, and B data. When the second gamma correction data of each block picture at different temperatures are stored in a table form, the second gamma correction data of each block picture corresponding to the current temperature, namely the second target gamma correction data of each block picture at the current temperature, can be acquired by looking up the table; when the second gamma correction data of each block picture at different temperatures are stored in the form of a curve, for each block picture, the second gamma correction data of the block picture corresponding to the current temperature, that is, the second target gamma correction data of the block picture at the current temperature, can be obtained through the curve corresponding to the block picture.

S1034: and carrying out gamma correction on the block picture according to the second target gamma correction data of the block picture at the current temperature.

A detailed description will be given below of a specific configuration of the first gamma correction data of the projection screen at different temperatures. Specifically, the method can be realized by the following steps [1] to [4 ]:

[1] and aiming at each preset temperature in the plurality of preset temperatures, constructing a corresponding color Lookup Table (LUT) of the projection picture at the preset temperature.

[2] And determining G data of the projection picture at the preset temperature and different digital signals based on the corresponding color lookup table of the projection picture at the preset temperature.

[3] And determining R data and B data of the projection picture at the preset temperature and different digital signals according to the target chromaticity coordinates based on the G data of the projection picture at the preset temperature and different digital signals.

In the present disclosure, the projection apparatus may be controlled to project pure white light onto the projection surface, and chromaticity coordinates of the light source portion of the projection apparatus may be measured by a standard instrument such as an illuminometer, an integrating sphere, or the like, and may be used as target chromaticity coordinates.

[4] And obtaining the R data, the B data and the G data of the projection picture under different temperatures and different digital signals through curve fitting according to the R data, the B data and the G data of the projection picture under each preset temperature and different digital signals, namely the gamma correction data of the projection picture under different temperatures.

The following is a detailed description of a specific embodiment of constructing a color lookup table corresponding to the projection picture at the preset temperature in the step [1 ]. Specifically, the method can be realized by the following steps (i) and (ii):

the method comprises the steps of controlling a projection device to project pure red light, pure green light and pure blue light to a projection plane in sequence, measuring a color value of a light source part of the projection device during each projection through standard instruments such as a luminometer, an integrating sphere and the like, and obtaining a color value (namely red X data X) when the saturation is 100% _R (N), red Y data Y _R (N), red Z data Z _R (N), X data X of green _G (N), green Y data Y _G (N), green Z data _G (N), X data of blue color X _B (N), blue Y data Y _B (N), green Z data _B (N), where N is the maximum value of the digital signal amplitude, e.g., 256, 1024, etc.);

secondly, since the brightness of the light source part generally conforms to Gamma2.2, the color values of the rest saturation can be calculated based on Gamma2.2, so that the color lookup table can be obtained.

For example, the color values of the remaining saturations can be calculated by the following equations (1) to (3):

wherein, X _R (IRE) is X data of red color with saturation IRE/N, IRE is digital signal amplitude, and IRE is [0, N-1 ]]Any integer within the range; y is _R (IRE) Y data for red color with saturation IRE/N; z _R (IRE) Z data for red with saturation IRE/N; x _G (IRE) X data for green with saturation IRE/N; y is _G (IRE) green Y data with saturation of IRE/N; z _G (IRE) Z data for green with saturation IRE/N; x _B (IRE) X data for blue color with saturation IRE/N; y is _B (IRE) Y data for blue color with saturation IRE/N; z _B (IRE) is Z data for blue color with saturation IRE/N.

Illustratively, N — 1024, the preset color lookup table obtained by the above method is shown in table 1 below:

TABLE 1 color lookup Table

IRE

X _R

Y _R

Z _R

X _G

Y _G

Z _G

X _B

Y _B

Z _B

0

X _R (0)

Y _R (0)

Z _R (0)

X _G (0)

Y _G (0)

Z _G (0)

X _B (0)

Y _B (0)

Z _B (0)

1

X _R (1)

Y _R (1)

Z _R (1)

X _G (1)

Y _G (1)

Z _G (1)

X _B (1)

Y _B (1)

Z _B (1)

2

…

3

…

1021

…

1022

…

1023

X _R (1023)

Y _R (1023)

Z _R (1023)

X _G (1023)

Y _G (1023)

Z _G (1023)

X _B (1023)

Y _B (1023)

Z _B (1023)

1024

X _R (1024)

Y _R (1024)

Z _R (1024)

X _G (1024)

Y _G (1024)

Z _G (1024)

X _B (1024)

Y _B (1024)

Z _B (1024)

In addition, if the brightness of the light source does not meet gamma2.2, the projection device is further controlled to project 100% white light (i.e. pure white light), 90% white light, 80% white light, … …, 10% white light to the projection surface in sequence at each preset temperature, and the color value of the light source of the projection device at each projection is measured by a standard instrument such as an illuminometer, an integrating sphere, etc., and then the color lookup table is obtained by linear interpolation according to all the color values measured by the standard instrument. The specific way of obtaining the color lookup table by linear interpolation is well known to those skilled in the art, and is not described in detail in this disclosure.

The following is a detailed description of a specific embodiment of determining G data of the projection picture at the preset temperature and different digital signals based on the color lookup table corresponding to the projection picture at the preset temperature in step [2 ].

For example, the G data of the projection picture at the preset temperature and different digital signals may be determined by the following equation (4) based on the corresponding color lookup table of the projection picture at the preset temperature:

GYV(IRE)＝(Y _G (N)-Y _G (0))(IRE/N) ^a +Y _G (0) (4)

wherein, gyv (IRE) is the G data of the projection image at the preset temperature and the digital signal amplitude IRE, i.e. the brightness value; a is a constant, and can be set as needed, and can be set to 2.2, 2.1, 2.0, 2.3, 2.4, and the like.

The following is a detailed description of a specific embodiment of determining R data and B data of the projection picture at the preset temperature and different digital signals according to the target chromaticity coordinates based on G data of the projection picture at the preset temperature and different digital signals in step [3 ].

Specifically, after the G data of the projection picture at the preset temperature and under different digital signals are determined, the G data may be fixed for the G data under each digital signal amplitude, and based on the chromaticity coordinate debugging principle, the R data and the B data under the digital signal amplitude, which minimize the distance between the chromaticity coordinate of the projection picture and the target chromaticity coordinate, are found, so as to obtain the R data, the G data and the B data of the projection picture at the preset temperature and under each digital signal.

The debugging principle of the chromaticity coordinates is as follows: the larger the amplitude of the digital signal corresponding to red is, the larger the x value of the chromaticity coordinate is, and the slightly larger the y value is; the larger the amplitude of the digital signal corresponding to green is, the larger the y value of the chromaticity coordinate is, and the slightly larger the x value is; the larger the amplitude of the digital signal corresponding to blue is, the smaller the x value and the y value of the chromaticity coordinate are.

In addition, the second gamma correction data of each block picture at different temperatures can be constructed in a manner similar to the specific construction manner of the first gamma correction data of the projection picture at different temperatures, which is not described in detail in this disclosure.

In addition, in order to further shorten the time length from the start of the projection equipment to the time when the temperature of the spatial light modulator reaches the preset steady-state temperature, the spatial light modulator can be heated by the heating assembly during the time period from the start of the projection equipment to the time when the temperature of the spatial light modulator reaches the preset temperature, so that the temperature of the spatial light modulator is quickly increased to the preset steady-state temperature, the time length of color cast of a projection picture is further shortened, the projection picture is quickly recovered to be normal, and the viewing experience of a user is further improved. In particular, the projection device may further comprise a heating assembly for heating the spatial light modulator. At this time, as shown in fig. 3, the above method may further include the following S105 and S106.

In S105, the heating assembly is controlled to operate in response to detecting the activation of the projection device.

In the present disclosure, the heating assembly may be, for example, a heating block, a heating film, a TEC heating module, or the like, and the present disclosure is not particularly limited. The heating assembly may be mounted directly on the surface of the spatial light modulator, or a TIM may be placed between the heating assembly and the spatial light modulator to reduce thermal contact resistance and improve heating performance.

When the heat dissipation assembly is the TEC refrigeration module and the heating assembly is the TEC heating module, the heat dissipation assembly and the heating assembly can be integrated into the TEC to improve the integration level of the projection equipment and reduce the hardware cost, and at the moment, the TCE can be controlled to heat or refrigerate by controlling the direction of voltage at two ends of the TEC.

Specifically, the controlling the heat dissipation assembly in S102 to operate at the second heat dissipation power includes: applying a first voltage in a first direction to two ends of the semiconductor refrigerator so that the semiconductor refrigerator works at a second heat dissipation power; the controlling the heating element to operate in S105 includes: a second voltage in a second direction is applied across the semiconductor refrigerator to cause the semiconductor refrigerator to heat the spatial light modulator, wherein the second direction is opposite to the first direction.

In addition, because the heat dissipation (or cold) performance is positively correlated with the surface area of the temperature control assembly, the larger the surface area is, the easier the heat or cold air is to dissipate, and the temperature adjustment is quicker. However, because the TEC is generally a temperature control component with a small surface area, heat or cold generated by the TEC is not easily dissipated, and temperature adjustment is slow, therefore, a heat dissipation plate may be additionally installed on the TEC to dissipate the heat or cold generated by the TEC through the heat dissipation plate, thereby increasing temperature adjustment speed. In addition, in order to further improve the temperature regulation speed, a fan can be additionally arranged on the radiating fin.

In S106, if the current temperature reaches the preset steady-state temperature, the heating assembly is controlled to stop working.

Fig. 4 is a block diagram illustrating an apparatus for color cast correction of a projection screen according to an exemplary embodiment, where the apparatus 300 may be applied to a projection device. Wherein the projection device includes a light source portion, a spatial light modulator, and a heat dissipation component for dissipating heat of the spatial light modulator, as shown in fig. 3, the apparatus 300 includes:

the control module 301 is configured to, in response to detecting that the projection apparatus is started, control the light source unit and the spatial light modulator to operate, and control the heat dissipation assembly to operate at a first heat dissipation power, so as to obtain a current temperature of the spatial light modulator;

the control module 301 is further configured to control the heat dissipation assembly to operate at a second heat dissipation power if the current temperature reaches a preset steady-state temperature, so as to stabilize the current temperature at the preset steady-state temperature, where a projection picture of the projection device has global color cast at the preset steady-state temperature, and the second heat dissipation power is greater than the first heat dissipation power;

a correction module 302, configured to perform gamma correction on the projection picture when the current temperature reaches the preset steady-state temperature, so as to implement color cast correction of the projection picture.

When the device detects that the projection equipment is started, the light source part and the spatial light modulator are controlled to work, and meanwhile, the heat dissipation assembly used for dissipating heat of the spatial light modulator is controlled to work at the first heat dissipation power lower than the second heat dissipation power, so that the heat dissipation assembly can dissipate heat of the spatial light modulator at a low heat dissipation rate, the temperature of the spatial light modulator is rapidly increased to a preset steady-state temperature, and gamma correction is carried out on a projection picture of the projection equipment when the temperature of the spatial light modulator reaches the preset steady-state temperature. Therefore, the time from the starting of the projection equipment to the time when the temperature of the spatial light modulator reaches the preset steady-state temperature can be shortened, namely the time for color cast of the projection picture is shortened, so that the projection picture is quickly recovered to be normal, and the impression experience of a user is improved. In addition, after the temperature of the spatial light modulator rapidly rises to the preset stable temperature, the temperature of the spatial light modulator is stabilized at the preset stable temperature through the heat dissipation assembly, so that the color cast of the projection picture is stable, the projection picture can be ensured to be put into a stable and color cast-free projection picture by performing gamma correction on the projection picture once when the current temperature reaches the preset stable temperature, and the projection picture does not need to be subjected to repeated gamma correction subsequently.

Optionally, the correction module 302 is further configured to perform γ correction on the projection picture according to a preset time period before the current temperature reaches the preset steady-state temperature.

Optionally, the correction module 302 includes:

Optionally, the projection screen includes a plurality of tile screens;

the correction module 302 is configured to perform gamma correction on each of the block pictures respectively.

Optionally, the correction module 302 includes:

the control module 301 is further configured to:

the control module 301 is configured to:

The present disclosure also provides a computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the steps of the method for color cast correction of a projection screen provided by the present disclosure.

Fig. 5 is a schematic diagram of a projection device 200 in one embodiment.

The projection apparatus 200 includes a projection section 210 and a driving section 220 that drives the projection section 210. The projection section 210 may form an optical image and project the optical image onto the imaging medium SC.

The projection unit 210 includes a light source unit 211, a spatial light modulator 212, and an optical system 213. The driving section 220 includes a light source driving section 221 and a light modulator driving section 222.

The light source part 211 may include a reflector and a sub-reflector that reflect light emitted from the light source to the spatial light modulator 212. The light source section 211 may further include a lens for improving optical characteristics of projection light, a polarizing plate, a light adjusting element for adjusting light flux, and the like.

The light source driving unit 221 may control the operation of the light source in the light source unit 211 according to an instruction from the control unit 250.

In this embodiment, the spatial light modulator 212 may be a panel 215 such as an LCOS, LCD, or DMD.

The spatial light modulator 212 is driven by the light modulator driving unit 222, and the light modulator driving unit 222 is connected to the image processing unit 245.

The image processing unit 245 inputs image data to the light modulator driving unit 222. The light modulator driving section 222 converts the input image data into a data signal suitable for the operation of the panel 215. The light modulator driving section 222 applies a voltage to each pixel of each panel 215 based on the converted data signal, and draws an image on each panel 215.

The optical system 213 includes a lens or a mirror or the like that images the incident image light PLA on the imaging medium SC. The optical system 213 may also include a zoom mechanism that enlarges or reduces the image projected onto the imaging medium SC, a focus adjustment mechanism that performs focus adjustment, and the like.

The projection apparatus 200 further includes an operation section 231, a signal receiving section 233, an input interface 235, a storage section 237, a data interface 241, an interface section 242, a frame memory 243, an image processing section 245, and a control section 250. The input interface 235, the storage unit 237, the data interface 241, the interface unit 242, the image processing unit 245, and the control unit 250 can mutually perform data communication via the internal bus 207.

The operation unit 231 may generate corresponding operation signals according to operations of various buttons and switches applied to the surface of the housing of the projection apparatus 200, and output the operation signals to the input interface 235. The input interface 235 includes a circuit that outputs an operation signal input from the operation unit 231 to the control unit 250.

The signal receiving unit 233 receives a signal (e.g., an infrared signal or a bluetooth signal) transmitted from the control device 5 (e.g., a remote controller), and decodes the received signal to generate a corresponding operation signal. The signal receiving unit 233 outputs the generated operation signal to the input interface 235. The input interface 235 outputs the received operation signal to the control section 250.

The storage unit 237 may be a magnetic recording device such as an HDD (Hard Disk Drive) or a storage device using a semiconductor memory element such as a flash memory. The storage unit 237 stores a program executed by the control unit 250, data processed by the control unit 250, image data, and the like.

The data interface 241 includes a connector and an interface circuit, and can be connected to the other electronic devices 100 by wire. The data interface 241 may be a communication interface that performs communication with other electronic devices 100. The data interface 241 receives image data, sound data, and the like from the other electronic device 100. In the present embodiment, the image data may be a content image.

The interface section 242 is a communication interface for communicating with another electronic device 100 according to the ethernet standard. The interface unit 242 includes a connector and an interface circuit that processes a signal transmitted by the connector. The interface part 242 is a main substrate that is an interface substrate including a connector and an interface circuit and is connected to the control part 250, and the main substrate is a substrate on which the processor 253 and other components are mounted. The connector and the interface circuit constituting the interface section 242 are mounted on the main board of the control section 250. The interface section 242 may receive setting information or instruction information transmitted from another electronic apparatus 100.

The control section 250 includes a memory 251 and a processor 253.

The memory 251 is a nonvolatile storage device that stores programs and data executed by the processor 253. The Memory 251 is configured by a semiconductor Memory element such as a magnetic Memory device or a flash-ROM (Read-Only Memory), or another type of nonvolatile Memory device. The Memory 251 may also include a Random Access Memory (RAM) constituting a work area of the processor 253. The memory 251 stores data processed by the control unit 250 and a control program executed by the processor 253.

The processor 253 may be constituted by a single processor, or may be constituted by a combination of a plurality of processing groups. The processor 253 executes a control program to control the respective portions of the projection apparatus 200. For example, the processor 253 executes corresponding image processing based on the operation signal generated by the operation unit 231, and outputs parameters used for the image processing (for example, parameters for performing keystone correction on an image) to the image processing unit 245. In addition, the processor 253 can control the light source driving part 221 to turn on or off the light source in the light source part 211 or adjust the brightness.

The image processing section 245 and the frame memory 243 may be formed of an integrated circuit. The Integrated Circuit includes an LSI (Large Scale Integrated Circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), wherein the PLD may include an FPGA (Field-Programmable Gate Array). The integrated circuit may also comprise a portion of an analog circuit, or a combination of a processor and an integrated circuit. The combination of the processor and the integrated circuit is called an MCU (micro controller Unit), an SoC (System on Chip), a System LSI, a chipset, or the like.

The image processing section 245 may store the image data received from the data interface 241 in the frame memory 243. The frame memory 243 includes a plurality of banks, each of which includes a memory capacity in which image data of one frame can be written. The frame Memory 243 may be composed of SDRAM (Synchronous Dynamic Random Access Memory) or DRAM (Dynamic Random Access Memory).

The image processing section 245 can perform image processing including resolution conversion, size adjustment, distortion correction, shape correction, digital zoom, image tone adjustment, image brightness adjustment, and the like on the image data stored in the frame memory 243.

The image processing section 245 may also convert an input frame frequency of the vertical synchronization signal into a drawing frequency and generate a vertical synchronization signal having the drawing frequency, which is referred to as an output synchronization signal. The image processing unit 245 outputs the output synchronization signal to the light modulator driving unit 222.

The foregoing description is only exemplary of the preferred embodiments of the disclosure and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the disclosure herein is not limited to the particular combination of features described above, but also encompasses other embodiments in which any combination of the features described above or their equivalents does not depart from the spirit of the disclosure. For example, the above features and (but not limited to) the features disclosed in this disclosure having similar functions are replaced with each other to form the technical solution.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order. Under certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. With regard to the apparatus in the above-described embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be elaborated here.

Claims

1. A color cast correction method of a projection picture is applied to a projection device, the projection device comprises a light source part, a spatial light modulator and a heat dissipation component used for dissipating heat of the spatial light modulator, and the method is characterized by comprising the following steps:

2. The method of claim 1, further comprising:

3. The method of claim 1 or 2, wherein the gamma correcting the projection picture comprises:

4. The method according to claim 1 or 2, wherein the projection picture comprises a plurality of block pictures;

the gamma correcting the projection picture comprises the following steps:

and respectively carrying out gamma correction on each block picture.

5. The method of claim 4, wherein the performing gamma correction on each of the block pictures respectively comprises:

determining a second target gamma correction data of each block picture at the current temperature;

and carrying out gamma correction on the block picture according to the second target gamma correction data.

6. The method according to claim 1 or 2, wherein the projection device further comprises a heating assembly for heating the spatial light modulator;

the method further comprises the following steps:

controlling the heating assembly to work in response to detecting that the projection equipment is started;

7. The method of claim 6, wherein the heat dissipation assembly and the heating assembly are integrated into a semiconductor chiller;

the controlling the heat dissipation assembly to work with a second heat dissipation power includes:

the controlling the heating assembly to operate comprises:

8. A color cast correcting device of a projection picture is applied to a projection device, the projection device comprises a light source part, a spatial light modulator and a heat dissipation component used for dissipating heat of the spatial light modulator, and the device is characterized by comprising:

9. A projection device, comprising:

a light source unit;

a spatial light modulator;

a memory having a computer program stored thereon;

a processor for executing the computer program in the memory to implement the steps of the method of any one of claims 1 to 7.

10. A computer-readable storage medium, on which computer program instructions are stored, which program instructions, when executed by a processor, carry out the steps of the method according to any one of claims 1 to 7.