TWI841086B - Projection system and calibration method thereof - Google Patents

Abstract

A projection system includes a light source module, an image device, a first light sensor, a second light sensor, and a processor. The light source module has a monochromatic solid-state light emitting device or multicolor solid-state light emitting devices. The processor is configured to: drive the solid-state light emitting device(s) to operate at different output powers based on different light source control signals and to project native full white patterns on screen through the image system sequentially; drive the first light sensor to sense the white light at different output powers sequentially and to generate corresponding first color information; drive the second light sensor to sense the native full white patterns on screen at different output powers sequentially and to generate corresponding second color information; obtain a relation between the first color information and the second color information; obtain a second target color information; obtain a first target color information; calibrate the corresponding light source control signals based on the first target color information.

Description

Projection system and correction method thereof

The present disclosure relates to a projection system and a calibration method thereof.

In recent years, optical projectors have been used in many fields, and the scope of application is gradually expanding, such as laser projection televisions to projectors used in flight simulators. Various optical projectors are widely used in schools, homes and commercial occasions.

Laser is a type of solid-state light source. For example, in laser projectors, automatic white balance correction is a method to solve the white balance shift caused by the different attenuation rates of blue laser diodes and yellow phosphors (and red laser diodes) over time. Among them, external correction is a method to use the light sensing value of an external light sensor at the maximum output power of the laser as the white balance target to improve the correction accuracy. However, standard instruments and related tools for external light sensors are not easy for general end users to obtain.

Therefore, how to come up with an optical projector that can solve the above problems is one of the problems that the industry is eager to invest research and development resources to solve.

In view of this, one purpose of the present disclosure is to provide a projection system and a calibration method thereof that can solve the above-mentioned problems.

To achieve the above object, according to an embodiment of the present disclosure, a projection system includes a light source module, an imaging device, a first light sensor, a second light sensor and a processor. The light source module has at least one solid-state light emitter. The processor signal is connected to the light source module, the first light sensor and the second light sensor, and is configured to execute a calibration procedure, which includes: driving at least one solid-state light emitter to generate different output powers according to different light source control signals, and sequentially emitting white light, and sequentially projecting a full white image on a screen through an imaging device; driving the first light sensor to sequentially sense the white light and correspondingly generate the first color information; driving the second light sensor to sequentially sense the full white image and correspondingly generate the second color information; obtaining the corresponding relationship between the first color information and the second color information; obtaining the target color information of the second color information according to a color space coordinate in the second color information; obtaining the target color information of the first color information according to the target color information of the second color information and the corresponding relationship; and calibrating the light source control signal corresponding to the different output powers according to the target color information of the first color information.

In one or more embodiments of the present disclosure, the aforementioned color space coordinates in the second color information are color space coordinates of a full white image generated by the solid-state light emitter with a maximum of different output powers.

In one or more embodiments of the present disclosure, the first color information is the color space coordinates sensed by the first light sensor when the solid-state light emitter emits white light at different output powers.

In one or more embodiments of the present disclosure, the second color information is the color space coordinates sensed by the second light sensor when the solid-state light emitter projects a full white image with different output powers.

In one or more embodiments of the present disclosure, the projection system further includes a light collecting box, which is arranged on the path of the white light and has an inlet, through which the white light enters the light collecting box and is evenly mixed in the light collecting box, wherein the first light sensor is arranged on the light collecting box.

In one or more embodiments of the present disclosure, the light collecting box further includes a reflector configured to allow a first portion of the white light to pass through and to turn the first portion of the white light to a second portion of the white light, the first light sensor configured to receive one of the first portion of the light and the second portion of the light, and the imaging device configured to receive the other of the first portion of the light and the second portion of the light.

In one or more embodiments of the present disclosure, the projection system further includes an optical fiber, wherein the light source module and the imaging device are respectively disposed at two ends of the optical fiber in an optical coupling manner.

In one or more embodiments of the present disclosure, the projection system further includes a housing, wherein the light source module and the imaging device are disposed in the housing, wherein the imaging device includes a light processing module and a projector lens.

In one or more embodiments of the present disclosure, the second photo sensor is a charge coupled device image sensor or a complementary metal oxide semiconductor image sensor.

In one or more embodiments of the present disclosure, the projection system further includes an input device and a display device. The input device is signal-connected to the processor. The input device is configured to receive a calibration input, and the processor is configured to execute a calibration procedure according to the calibration input. The display device is signal-connected to the processor and configured to display the execution result of the calibration procedure.

According to another embodiment of the present disclosure, a calibration method for a projection system includes: driving at least one solid-state light emitter to generate different output powers according to different light source control signals, and sequentially emitting white light, and sequentially projecting a full white image on a screen through an imaging device; driving a first light sensor to sequentially sense white light, and correspondingly generate first color information; driving a second light sensor to sequentially sense the full white image, and correspondingly generate second color information; obtaining a corresponding relationship between the first color information and the second color information; obtaining target color information of the second color information according to a color space coordinate in the second color information; obtaining target color information of the first color group according to the target color information of the second color information and the corresponding relationship; and calibrating the light source control signals corresponding to the different output powers according to the target color information of the first color information.

In one or more embodiments of the present disclosure, the target color information for obtaining the second color information according to the aforementioned color space coordinates in the second color information is the color space coordinates of a full white image generated by the solid-state light emitter with the maximum of different output powers.

In one or more embodiments of the present disclosure, the first color information is the color space coordinates sensed by the first light sensor when the solid-state light emitter emits white light at different output powers.

In one or more embodiments of the present disclosure, the second color information is the color space coordinates sensed by the second light sensor when the solid-state light emitter projects a full white image with different output powers.

In one or more embodiments of the present disclosure, the first color information and the second color information both include color space coordinates.

In one or more embodiments of the present disclosure, the different relationships between the first color information and the second color information are linear relationships or N-order polynomial function relationships.

In one or more embodiments of the present disclosure, the light source control signal is a current signal input to a solid-state light emitter.

In summary, in the projection system and calibration method disclosed herein, an external light sensor, i.e., a so-called standard instrument, is built into the projection system as the second light sensor of the projection system, thereby solving the problem that the end customer needs to purchase a standard instrument and related tools for external calibration. In addition, a processor is used to drive the second light sensor and the original first light sensor to perform data sampling respectively, and then the target of the light source control signal calibration is obtained through the algorithm pre-written in the processor, and then the processor automatically adjusts the light source control signal input to the solid-state light emitter, thus completing the auto white balance calibration. This operation can be conveniently selected in the general function options when setting up the projection system or conducting factory-side production tests. Therefore, compared with the currently common projection systems and calibration methods, the projection system and calibration method disclosed herein can simplify the instruments and operation steps required in the calibration process in terms of automatic white balance calibration, and further improve the ease of self-testing by end users or factories.

The above description is only used to explain the problem to be solved by the present disclosure, the technical means for solving the problem, and the effects produced, etc. The specific details of the present disclosure will be introduced in detail in the following implementation method and related drawings.

The following will disclose multiple embodiments of the present disclosure with drawings. For the purpose of clarity, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present disclosure. In other words, in some embodiments of the present disclosure, these practical details are not necessary. In addition, in order to simplify the drawings, some commonly used structures and components will be depicted in the drawings in a simple schematic manner.

Please refer to FIG. 1 , which is a schematic diagram of a projection system 100 according to an embodiment of the present disclosure. As shown in FIG. 1 , the projection system 100 includes a light source module 120 , an accumulated light box 124 , an imaging device 130 , a first light sensor 126 , and a second light sensor 133 .

The light source module 120 has at least one solid-state light emitting device 121 for generating white light. For example, the solid-state light emitting device 121 may be a laser diode, an organic laser diode (OLD) or a similar light emitter. Furthermore, the solid-state light emitter 121 may use a blue laser diode to excite phosphor to generate other colored lights, and mix them to generate white light. It is also possible to use multiple laser diodes to simultaneously generate different colored lights to mix and generate white light, such as red, green, and blue or red, yellow, and blue, where the yellow part is a yellow phosphor.

As shown in FIG. 1 , a reflector 122 that partially transmits the first portion of light and partially reflects the second portion of light is disposed on the path of the white light emitted by the solid-state light emitter 121. The reflector 122 allows the first portion of light to pass through and redirects the second portion of light. The first portion of light enters the light collecting box 124 through the inlet 124a of the light collecting box 124 and the diffusion sheet 125.

The light-integrating box 124 can be an integral sphere box or a similar light-homogenizing element. For example, the integral sphere box is composed of a reflector and uses multiple internal reflections to make the light uniform. With this optical path configuration, the light-integrating box 124 can be set at a position that will not be affected by the reflected light of the second part of the light, thereby improving the accuracy of the light-sensing value generated by the first light sensor 126 set on the light-integrating box 124 to receive the first part of the light. In this way, the white balance correction based on this light-sensing value can also have better accuracy.

In detail, in the embodiment corresponding to FIG. 1 , the projection system 100 further includes a relay mirror 123a. The relay mirror 123a is located between the reflector 122 and the entrance 124a of the light collecting box 124, and focuses the first part of the light passing through the reflector 122 into the light collecting box 124. After the first part of the light is uniformed by the light collecting box 124, it is received by the first light sensor 126. After the second part of the light is turned by the reflector 122, it enters the imaging device 130 through the entrance 132a. The imaging device 130 is configured to collect the second part of the light into an image through the light processing module 132 and the projection lens 131 therein, and project it to a predetermined position outside the projection system 100 (for example, on a projection screen S or other objects).

The light source module 120, the reflector 122, the light collecting box 124, the second light sensor 133 and the processor 134 are all disposed in the housing 110. The imaging device 130 is at least partially disposed in the housing 110, but the present disclosure is not intended to be limited to this configuration.

In some implementations, the second photo sensor 133 may be a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor.

The imaging device 130 includes a projection lens 131 exposed outside the housing 110 and a light processing module 132 disposed in the housing 110. The light processing module 132 is configured to effectively redirect the second portion of light incident into the imaging device 130 to a projection chip (not shown), and after the second portion of light is reflected by the projection chip, the full white image P required for imaging is projected. The projection lens 131 is configured to project the full white image P onto a projection screen S or other objects.

In the embodiment corresponding to FIG. 1 , a coating with high reflectivity is disposed on the reflective plane 122a of the reflector 122. Specifically, the reflectivity of the reflective plane 122a is such that the first portion of light passing through the reflector 122 accounts for approximately 1% of the white light emitted by the solid-state light emitter 121 (that is, the second portion of light reflected by the reflector 122 accounts for approximately 99% of the white light emitted by the solid-state light emitter 121), but the present disclosure is not limited to this reflectivity.

In other embodiments, if the reflectivity of the reflector 122 is such that the proportion of the second portion of light in the total white light is smaller than that of the first portion of light, the configuration of the components and the optical path is changed so that the second portion of light is directed to the light collecting box 124, and the first portion of light is transmitted and enters the imaging device 130. (Not shown in the figure) In this embodiment, the imaging device 130 is configured to receive the first portion of light.

In order to capture external projection information for automatic white balance calibration, the projection system 100 includes a processor 134. The processor 134 is signal-connected to the light source module 120, the first light sensor 126, and the second light sensor 133. The processor 134 can transmit different light source control signals to the light source module 120 to adjust the white light emitted by the solid-state light emitter 121, and can also obtain the light sensing values from the first light sensor 126 and the second light sensor 133. The calibration method 200 achieved by the processor 134 is shown in FIG. 2. FIG. 2 is a schematic diagram showing a calibration method 200 of the projection system 100 according to an embodiment of the present disclosure.

The calibration method 200 begins by performing operations 210, 220, and 230. First, the output power of the light sensing value sampling is determined, for example, 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, and 30%. Next, after the projection system 100 has been warmed up for at least 15 minutes, the processor 134 transmits a light source control signal corresponding to the 100% output power to the light source module 120 to drive the solid-state light emitter 121 to emit white light at the 100% output power. The second part of the white light is projected onto a predetermined position (e.g., a projection screen S or an object) outside the projection system 100 through the light processing module 132 and the projection lens 131 to form a full white image P. Next, the processor 134 drives the first light sensor 126 to sense the first portion of light transmitted through the reflector 122, and generates first color information corresponding to an output power of 100%. Finally, the processor 134 drives the second light sensor 133 to sense the full white image P projected at the predetermined position, and generates second color information corresponding to an output power of 100%.

Then, the processor 134 sequentially transmits light source control signals corresponding to the output powers of 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35% and 30% to the light source module 120 to drive the solid-state light emitter 121 to sequentially emit white light at the output powers of 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35% and 30%, and generate the first color information and the second color information corresponding to the output powers of 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35% and 30%. In this embodiment, the first color information and the second color information are obtained in the form of an XYZ color space, wherein X, Y, and Z are coordinates of primary colors, the X coordinate represents red light, the Y coordinate represents green light, and the Z coordinate represents blue light, and are respectively the intensities of different color lights reflected in the sensor. Thus, after completing operations 210, 220, and 230, the solid-state light emitter 121 generates a total of fifteen white lights and fifteen full white images P (as shown in FIG. 1 ) when the output power is 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, and 30%, so the first color information includes fifteen color space coordinates of the fifteen white lights measured by the first light sensor 126, and the second color information includes fifteen color space coordinates of the fifteen full white images P (as shown in FIG. 1 ) measured by the second light sensor 133. In some implementations, the first color information and the second color information may also be obtained in the form of RGB color space.

As described above, the processor 134 can adjust the white light emitted by the solid-state light emitter 121 by transmitting different light source control signals. Generally speaking, the light sensing value that can be sensed by the first light sensor 126 receiving the second portion of light can be inferred from the light source control signal according to a specific correspondence. In addition, this correspondence will vary depending on the equipment conditions (such as the reflectivity of the reflector 122), and these correspondences are all recorded in the processor 134.

Similarly, under a fixed external environment, the light sensing value obtained by the second light sensor 133 and the light sensing value obtained by the first light sensor 126 can also find a fixed corresponding relationship. However, since the external environment can change greatly, in the calibration method 200 disclosed in the present invention, the processor 134 obtains this corresponding relationship according to the data sensed on site during each calibration.

For example, as shown in FIG. 2 , the calibration method 200 includes an operation 240 that obtains the linear relationship of each coordinate using a first-order linear regression model based on the fifteen color space coordinates of the first color information and the second color information obtained previously. For example, in this embodiment, the operation 240 obtains the linear relationship of the X coordinate of the first color information to the X coordinate of the second color information, the linear relationship of the Y coordinate of the first color information to the Y coordinate of the second color information, and the linear relationship of the Z coordinate of the first color information to the Z coordinate of the second color information, a total of three relationships. It should be understood that a person skilled in the art can select different models to obtain corresponding relationships based on the trends and correlations of the sampled data, such as N-order polynomial regression, without departing from the scope of this disclosure.

Next, the calibration method 200 includes an operation 250. In the operation 250, a portion of the data is selected from the second color information as a reference. For example, the color space coordinates (X ₁₀₀ , Y ₁₀₀ , Z ₁₀₀ ) of the full white image P (as shown in FIG. 1 ) measured by the second light sensor 133 when the output power is 100% are used as a reference to calculate the chromaticity coordinate (x ₁₀₀ , y ₁₀₀ ). The conversion between the chromaticity coordinate (x, y) and the color space coordinate (X, Y, Z) is shown in the following equations (1) and (2).

Next, the target color information of the second color information is obtained by aiming that the all-white image P (as shown in FIG. 1) projected at different output powers can obtain the same chromaticity coordinates as (x ₁₀₀ , y ₁₀₀ ). Specifically, when the chromaticity coordinates at different output powers are all equal to (x ₁₀₀ , y ₁₀₀ ), the ratio between each color space coordinate X, Y, Z at each output power and each color space coordinate X ₁₀₀ , Y ₁₀₀ , Z ₁₀₀ when the output power is 100% is fixed. Taking the case where the output power is A% as an example, when the output power is A% and the chromaticity coordinates are equal to ( _x100 , _y100 ), the proportional relationship between the light sensitivity values of _XA , _YA , _ZA and _X100 , _Y100 , _Z100 is as shown in formula (3).

In this way, when the light sensitivity values of _X100 , _Y100 , and _Z100 are known, the values of the other two can be obtained by giving any one of _XA , _YA, and _ZA . For example, the second color information of the solid-state light emitter 121 before calibration when the output power is 50% is sensed to be (X ₅₀ , Y ₅₀ , Z ₅₀ ). If the light sensing value of Y ₅₀ is retained (i.e., Y _A is designated to be equal to Y ₅₀ ), and X _A and Z _A are calculated by using the ratio of Y 50 to Y ₁₀₀ , then X _A is the target value X ₅₀ ′ of X ₅₀ , and Z _A is the target value Z ₅₀ ′ of Z _50. The target color space coordinates (X ₅₀ ′, Y ₅₀ , Z ₅₀ ′) obtained represent that the full white image P with this color space coordinate (i.e., the full white image P generated by the calibrated projection system 100 when the output power is 50%) has the same chromaticity coordinates as the full white image P when the output power is 100%. When operation 250 is completed, the obtained fifteen target color space coordinates constitute the target color information of the second color information.

In some implementations, the chromaticity coordinates used as a reference are not limited to being obtained from the second color information. For example, the chromaticity coordinates (0.3127, 0.3290) of the reference white are used as a reference, the light sensitivity value of Y ₁₀₀ in operation 230 is retained, and the target values X ₁₀₀ ' and Z ₁₀₀ ' of X ₁₀₀ and Z ₁₀₀ are deduced, and the other output powers are deduced in the same way, and fifteen target color space coordinates can also be obtained to form the target color information of the second color information.

The calibration method 200 includes an operation 260. In the operation 260, the fifteen target color space coordinates in the target color information are respectively substituted into the corresponding relationship obtained in the operation 240, such as a linear regression relationship, to obtain fifteen color space coordinates. The fifteen color space coordinates represent that when the output power is 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35% and 30%, in order to achieve that the projected full white image P has the same chromaticity coordinates as the projected full white image P when the output power is 100%, the solid-state light emitter 121 needs to be calibrated to enable the first light sensor 126 to sense the fifteen color space coordinates obtained in the operation 260 under the fifteen output powers. These fifteen color space coordinates constitute the target color information of the first color information.

As described above, the processor 134 presets a correspondence between the first color information and the light source control signal for controlling the solid-state light emitter 121. Therefore, in operation 270 of the calibration method 200, the light source control signal that enables the first light sensor 126 to sense the target color information of the first color information is obtained through this correspondence. In some embodiments, the light source control signal includes different forms, such as current values for driving three-color laser diodes respectively, but the present disclosure is not intended to be limited thereto.

Please refer to FIG. 3, which is a schematic diagram of a projection system 300 according to another embodiment of the present invention. As shown in FIG. 3, the projection system 300 includes a housing 110 and a housing 140 that are separated. The light source module 120, the reflector 122, the relay mirror 123a, the light collecting box 124 and the first light sensor 126 are disposed in the housing 110. The second light sensor 133 and the processor 134 are disposed in the housing 140. The imaging device 130 is at least partially disposed in the housing 140. The imaging device 130 includes a projection lens 131 exposed outside the housing 140 and a light processing module 132 disposed in the housing 140.

As shown in FIG. 3 , the light source module 120 includes a solid-state light emitter 121. The light-collecting box 124 includes a diffusion sheet 125. The first light sensor 126 is disposed on the light-collecting box 124. The imaging device 130 includes a light processing module 132 and a projection lens 131. The configuration of these components and the calibration method of the projection system 300 are the same or similar to those disclosed in the embodiments shown in FIG. 1 and FIG. 2 , and therefore will not be described in detail here. Please refer to the relevant description in the previous text.

In particular, the difference between the embodiment corresponding to FIG. 3 and the embodiment of FIG. 1 is that the projection system 300 changes the optical coupling method between the light source module 120 and the imaging device 130. Specifically, in the embodiment corresponding to FIG. 3, the projection system 300 further includes an optical fiber 150, wherein the housing 110 further includes a relay mirror 123b, and the imaging device 130 further includes an integrating rod 135. The light source module 120 is optically coupled to one end of the optical fiber 150, and the imaging device 130 is optically coupled to the other end of the optical fiber 150 via the integrating rod 135. In other words, after being reflected by the reflector 122, the second part of light is focused by the relay mirror 123b, enters the optical fiber 150 from one end of the optical fiber 150, and then reaches the integrating rod 135 of the imaging device 130 through the other end of the optical fiber 150. With this structural configuration, the flexibility of the projection system 300 in the optical path design can be effectively increased.

In the present disclosure, the projection system 100 or the projection system 300 to which the calibration method 200 is applied can complete the automatic white balance calibration under the drive of the processor 134. Therefore, in some embodiments, the projection system 100 or the projection system 300 further includes an input device 136 and a display device 137. The input device 136 and the display device 137 are respectively connected to the processor 134 by signals. The input device 136 is configured to receive a calibration input related to the automatic white balance calibration from a user, and the processor 134 is configured to execute a calibration program (such as the calibration method 200) according to the calibration input. After the calibration program is executed, the display device 137 displays the execution result of the calibration program. For example, the input device 136 may be a keyboard, the display device 137 may be a display screen, or the input device 136 and the display device 137 may be integrated into a touch display module. The user may start the calibration procedure of the automatic white balance calibration by one key through the input device 136, and the display device 137 may display the calibration result or error message after the calibration is completed. In this way, the user may operate directly on the projection system 100 or the projection system 300 without connecting other devices.

From the above detailed description of the specific implementation of the present disclosure, it can be clearly seen that in the projection system and calibration method disclosed herein, an external light sensor, i.e., a so-called standard instrument, is built into the projection system as the second light sensor of the projection system, thereby solving the problem that the end customer needs to purchase a standard instrument and related tools for external calibration. In addition, a processor is used to drive the second light sensor and the original first light sensor to perform data sampling respectively, and then the target of the light source control signal calibration is obtained through the algorithm pre-written in the processor, and then the processor automatically adjusts the light source control signal input to the solid-state light emitter, thereby completing the automatic white balance calibration. This operation can be conveniently selected in the general function options when setting up the projection system or conducting factory-side production tests. Therefore, compared with the currently common projection systems and calibration methods, the projection system and calibration method disclosed herein can simplify the instruments and operation steps required in the calibration process in terms of automatic white balance calibration, and further improve the ease of self-testing by end users or factories.

Although the present disclosure has been disclosed in the above implementation form, it is not intended to limit the present disclosure. Anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be determined by the scope of the attached patent application.

100,300: projection system 110,140: housing 120: light source module 121: solid-state light emitter 122: reflector 122a: reflection plane 123a,123b: relay mirror 124: light integrating box 124a,132a: entrance 125: diffusion sheet 126: first light sensor 130: imaging device 131: projection lens 132: light processing module 133: second light sensor 134: processor 135: integration column 136: input device 137: display device 150: optical fiber 200: calibration method 210,220,230,240,250,260,270: Operation P: All white image S: Projection screen

In order to make the above and other purposes, features, advantages and embodiments of the present disclosure more clearly understandable, the attached drawings are described as follows: Figure 1 is a schematic diagram of a projection system according to an embodiment of the present disclosure. Figure 2 is a schematic diagram of a calibration method of a projection system according to an embodiment of the present disclosure. Figure 3 is a schematic diagram of a projection system according to an embodiment of the present disclosure.

Domestic storage information (please note in the order of storage institution, date, and number) None Foreign storage information (please note in the order of storage country, institution, date, and number) None

200: Calibration method

210,220,230,240,250,260,270: Operation

Claims (17)

A projection system comprises: a light source module having at least one solid-state light emitter; an imaging device; a first light sensor; a second light sensor; and a processor, which is signal-connected to the light source module, the first light sensor and the second light sensor and configured to execute a calibration procedure, the calibration procedure comprising: driving the at least one solid-state light emitter to generate a plurality of output powers according to a plurality of light source control signals, and sequentially emitting a plurality of white lights, and sequentially projecting a plurality of full-white images on a screen through the imaging device; driving the first light sensor to sequentially sense the white lights and generate a first color information accordingly; driving the second light sensor to sequentially sense the full-white images and generate a second color information accordingly; Obtain a corresponding relationship between the first color information and the second color information; Obtain a target color information of the second color information according to a color space coordinate in the second color information; Obtain a target color information of the first color information according to the target color information of the second color information and the corresponding relationship; and Correct the light source control signals corresponding to the output powers according to the target color information of the first color information. A projection system as described in claim 1, wherein the color space coordinate in the second color information is a color space coordinate of the full white image generated by the at least one solid-state light emitter with one of the maximum output powers. The projection system as described in claim 1, wherein the first color information is a plurality of color space coordinates sensed by the first light sensor when the at least one solid-state light emitter emits the white lights at the output powers. A projection system as described in claim 1, wherein the second color information is a plurality of color space coordinates sensed by the second light sensor when the at least one solid-state light emitter projects the all-white images at the output powers. The projection system as described in claim 1 further includes a light collecting box, which is arranged on the path of the white lights and has an inlet, through which the white lights enter the light collecting box and are evenly mixed in the light collecting box, wherein the first light sensor is arranged on the light collecting box. In the projection system as described in claim 5, the light collecting box further includes a reflector configured to allow a first portion of each of the white lights to pass through and to turn a second portion of each of the white lights, the first light sensor is configured to receive one of the first portion of light and the second portion of light, and the imaging device is configured to receive the other of the first portion of light and the second portion of light. The projection system as described in claim 1 further comprises an optical fiber, wherein the light source module and the imaging device are respectively arranged at two ends of the optical fiber in an optical coupling manner. The projection system as described in claim 1 further comprises a housing, wherein the light source module and the imaging device are disposed in the housing, wherein the imaging device comprises a light processing module and a projector lens. A projection system as described in claim 1, wherein the second light sensor is a charge coupled device image sensor or a complementary metal oxide semiconductor. The projection system as described in claim 1 further comprises: an input device, signal-connected to the processor, the input device configured to receive a correction input, the processor configured to execute the correction procedure according to the correction input; and a display device, signal-connected to the processor, and configured to display an execution result of the correction procedure. A calibration method for a projection system, comprising: Driving at least one solid-state light emitter to generate a plurality of output powers according to a plurality of light source control signals, and sequentially emitting a plurality of white lights, and sequentially projecting a plurality of full-white images on a screen through an imaging device; Driving a first light sensor to sequentially sense the white lights, and correspondingly generating a first color information; Driving a second light sensor to sequentially sense the full-white images, and correspondingly generating a second color information; Obtaining a corresponding relationship between the first color information and the second color information; Obtaining a target color information of the second color information according to a color space coordinate in the second color information; Obtaining a target color information of the first color information according to the target color information of the second color information and the corresponding relationship; and The light source control signals corresponding to the output powers are corrected according to the target color information of the first color information. A calibration method for a projection system as described in claim 11, wherein a target color information of the second color information is obtained based on the color space coordinates in the second color information, which is a color space coordinate of the full white image generated by the at least one solid-state light emitter with one of the largest output powers. A calibration method for a projection system as described in claim 11, wherein the first color information is a plurality of color space coordinates sensed by the first light sensor when the at least one solid-state light emitter emits the white lights at the output powers. A calibration method for a projection system as described in claim 11, wherein the second color information is a plurality of color space coordinates sensed by the second light sensor when the at least one solid-state light emitter projects the all-white images with the output powers. A calibration method for a projection system as described in claim 11, wherein the first color information and the second color information both include a plurality of color space coordinates. A calibration method for a projection system as described in claim 11, wherein the corresponding relationship between the first color information and the second color information is a linear relationship or an N-order polynomial function relationship. A calibration method for a projection system as described in claim 11, wherein the light source control signals are a plurality of current signals input into the at least one solid-state light emitter.

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