Laser projection equipment

Abstract

The present application discloses a laser projection device, comprising a light source for irradiating four colors of light onto a light valve; the light valve is configured to sequentially receive the irradiation of the aforementioned colors of light; a driving circuit for receiving an image signal for a projected image, the image signal comprising a first color initial value, a second color initial value, and a third color initial value for each pixel in the projected image; and the driving circuit is further configured to determine four color target values ​​for each pixel based on the initial values ​​of the three colors of each pixel, wherein the fourth color target value is determined by the first color initial value and the second color initial value; and the driving circuit is further configured to control the flipping of the light valve based on the color of the light irradiated by the light source onto the light valve and the four color target values ​​of the pixel. Because the present application can increase the color light generated by the light source and integrate the increased color light generated by the light source into the displayed projected image, the brightness of the displayed image is improved.

Description

[0001] This application is a divisional application based on Chinese invention application 202010156634.1 (2020-03-09), invention name: Laser projection method and device. Technical Field

[0002] The present disclosure relates to the field of laser projection, and in particular to a laser projection method and device. Background Art

[0003] Currently, laser projection equipment can include a driver circuit, a blue laser, a phosphor wheel (also known as a color filter wheel), a light valve, and a projection lens. During the projection of an image, the blue laser light emitted by the blue laser sequentially illuminates different areas of the phosphor wheel, generating three-color light: blue, red, and green. The driver circuit receives an image signal from a front-end device (such as a computer) containing the red, green, and blue values ​​for each pixel in the projected image. The driver circuit then controls the flipping of the light valve based on the color of the light irradiated by the light source and the red, green, and blue values ​​of each pixel. The light valve modulates each color of light into an image beam and transmits the image beam to the projection lens, thereby displaying the image.

[0004] However, since only three colors of light are projected to realize image display, the brightness of the displayed image is low. Summary of the Invention

[0005] The embodiments of the present disclosure provide a laser projection method and device that can solve the problem in related technologies of low brightness of displayed images due to the fact that only three-color light is projected to achieve image display. The technical solution is as follows:

[0006] In one aspect, a laser projection method is provided, which is applied to a driving circuit of a laser projection device, wherein the laser projection device further comprises a light source and a light valve. The method comprises:

[0007] receiving an image signal of a projected image, the image signal comprising a first color initial value, a second color initial value, and a third color initial value for each pixel in the projected image;

[0008] Determining a first color target value, a second color target value, a third color target value, and a fourth color target value of the pixel according to the first color initial value, the second color initial value, and the third color initial value of each pixel, wherein the sum of the first color target value, the second color target value, the third color target value, and the fourth color target value is greater than or equal to the sum of the first color initial value, the second color initial value, and the third color initial value;

[0009] The light valve is controlled to flip according to the color of the light emitted from the light source to the light valve, and the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel.

[0010] Optionally, determining the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel according to the first color initial value, the second color initial value, and the third color initial value of each pixel includes:

[0011] If the first color initial value, the second color initial value, and the third color initial value do not meet the target condition, determining that the third color target value is equal to the third color initial value;

[0012] determining the first color target value, the second color target value, and the fourth color target value according to the first color initial value and the second color initial value;

[0013] The target conditions include one or more of the following conditions:

[0014] The target color initial value among the first color initial value, the second color initial value and the third color initial value is a color upper limit value, and the other color initial values ​​except the target color initial value are color lower limit values;

[0015] The first color initial value, the second color initial value, and the third color initial value are all the color upper limit values.

[0016] Optionally, determining the first color target value, the second color target value, and the fourth color target value according to the first color initial value and the second color initial value of the pixel includes:

[0017] respectively detecting whether the first color initial value is greater than a first threshold value and whether the second color initial value is greater than a second threshold value;

[0018] If the first color initial value is greater than the first threshold, and the second color initial value is less than or equal to the second threshold; or, the first color initial value is less than or equal to the first threshold, and the second color initial value is greater than the second threshold; or, the first color initial value is less than or equal to the first threshold, and the second color initial value is less than or equal to the second threshold, compare the first ratio with the second ratio;

[0019] If the first ratio is equal to the second ratio, determining that the first color target value and the second color target value are both equal to the color lower limit value, and determining that the fourth color target value is equal to the product of the third ratio and the color upper limit value;

[0020] Among them, the first ratio is the ratio of the first color initial value to the second color initial value, the second ratio is the ratio of the first threshold to the second threshold, the third ratio is the ratio of the first color initial value to the first threshold, or the third ratio is the ratio of the second color initial value to the second threshold.

[0021] Optionally, after comparing the first ratio and the second ratio, if the first ratio is smaller than the second ratio, the method further includes:

[0022] Determining that the first color target value is equal to the color lower limit value;

[0023] Determine the fourth color target value to be equal to the product of a fourth ratio and the color upper limit value, where the fourth ratio is the ratio of the first color initial value to the first threshold value;

[0024] Determine that the second color target value is equal to the product of the fifth ratio and the color upper limit value, the fifth ratio is the ratio of the first difference to the second difference, the first difference is the difference between the second color initial value and the product of the fourth ratio and the second threshold value, and the second difference is the difference between the color upper limit value and the second threshold value.

[0025] Optionally, after comparing the first ratio and the second ratio, if the first ratio is greater than the second ratio, the method further includes:

[0026] Determining that the second color target value is equal to the color lower limit value;

[0027] Determine that the fourth color target value is equal to a product of a sixth ratio and the color upper limit value, where the sixth ratio is a ratio of the second color initial value to the second threshold value;

[0028] Determine that the first color target value is equal to the product of the seventh ratio and the color upper limit value, the seventh ratio is the ratio of the third difference to the fourth difference, the third difference is the difference between the first color initial value and the product of the sixth ratio and the first threshold value, and the fourth difference is the difference between the color upper limit value and the first threshold value.

[0029] Optionally, after respectively detecting whether the first color initial value is greater than a first threshold value and whether the second color initial value is greater than a second threshold value, the method further includes:

[0030] If the first color initial value is greater than the first threshold value, and the second color initial value is greater than the second threshold value, determining the fourth color target value to be the color upper limit value;

[0031] Determine the first color target value to be equal to the product of an eighth ratio and the color upper limit value, where the eighth ratio is the ratio of the difference between the first color initial value and the first threshold value to a fourth difference value, where the fourth difference is the difference between the color upper limit value and the first threshold value;

[0032] Determine that the second color target value is equal to the product of the ninth ratio and the color upper limit value, the ninth ratio is the ratio of the difference between the second color initial value and the second threshold value to the second difference, and the second difference is the difference between the color upper limit value and the second threshold value.

[0033] Optionally, if the first color initial value, the second color initial value, and the third color initial value meet the target condition, the method further includes:

[0034] If the target color initial value among the first color initial value, the second color initial value, and the third color initial value is a color upper limit value, and the color initial values ​​other than the target color initial value are color lower limit values, determining that the color target value corresponding to the target color initial value is equal to the color upper limit value, and determining that the color target values ​​other than the color target value corresponding to the target color initial value are equal to the color lower limit value;

[0035] If the first color initial value, the second color initial value, and the third color initial value are all the color upper limit values, determine that the first color target value, the second color target value, the third color target value, and the fourth color target value are all equal to the color upper limit value.

[0036] On the other hand, a laser projection device is provided, the laser projection device comprising: a driving circuit, a light source and a light valve;

[0037] The driving circuit is configured to receive an image signal of a projected image, wherein the image signal includes a first color initial value, a second color initial value, and a third color initial value for each pixel in the projected image;

[0038] The driving circuit is further configured to determine a first color target value, a second color target value, a third color target value, and a fourth color target value of the pixel based on the first color initial value, the second color initial value, and the third color initial value of each pixel, wherein the sum of the first color target value, the second color target value, the third color target value, and the fourth color target value is greater than or equal to the sum of the first color initial value, the second color initial value, and the third color initial value;

[0039] The driving circuit is further configured to control the flipping of the light valve according to the color of the light emitted by the light source to the light valve, and the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel.

[0040] Optionally, the driving circuit is further used to:

[0041] If the first color initial value, the second color initial value, and the third color initial value do not meet the target condition, determining that the third color target value is equal to the third color initial value;

[0042] determining the first color target value, the second color target value, and the fourth color target value according to the first color initial value and the second color initial value;

[0043] The target conditions include one or more of the following conditions:

[0044] The target color initial value among the first color initial value, the second color initial value and the third color initial value is a color upper limit value, and the other color initial values ​​except the target color initial value are color lower limit values;

[0045] The first color initial value, the second color initial value, and the third color initial value are all the color upper limit values.

[0046] Optionally, the driving circuit is further used to:

[0047] respectively detecting whether the first color initial value is greater than a first threshold value and whether the second color initial value is greater than a second threshold value;

[0048] If the first color initial value is greater than the first threshold, and the second color initial value is less than or equal to the second threshold; or, the first color initial value is less than or equal to the first threshold, and the second color initial value is greater than the second threshold; or, the first color initial value is less than or equal to the first threshold, and the second color initial value is less than or equal to the second threshold, compare the first ratio with the second ratio;

[0049] If the first ratio is equal to the second ratio, determining that the first color target value is equal to the color lower limit value, determining that the second color target value is equal to the color lower limit value, and determining that the fourth color target value is equal to the product of the third ratio and the color upper limit value;

[0050] Among them, the first ratio is the ratio of the first color initial value to the second color initial value, the second ratio is the ratio of the first threshold to the second threshold, the third ratio is the ratio of the first color initial value to the first threshold, or the third ratio is the ratio of the second color initial value to the second threshold.

[0051] The beneficial effects of the technical solutions provided by the embodiments of the present disclosure include at least:

[0052] The disclosed embodiments provide a laser projection method and device, which can determine the first color target value, second color target value, third color target value, and fourth color target value of each pixel in the projected image based on the first color initial value, second color initial value, and third color initial value of the pixel. The light valve is controlled to flip based on the color of the light emitted by the light source to the light valve, as well as the first color target value, second color target value, third color target value, and fourth color target value of the pixel. The disclosed embodiments increase the color light generated by the light source, determine the color target values ​​corresponding to the four colors of light based on the color initial values ​​of the three colors of each pixel in the projected image, and control the flipping of the light valve based on the color target values ​​corresponding to the four colors of light, thereby integrating the increased color light into the displayed projected image. This improves the brightness of the displayed image compared to the related art that only projects three colors of light to achieve image display. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0054] Figure 1 is a structural schematic diagram of a laser projection device provided by an embodiment of the present disclosure;

[0055] Figure 2 is a schematic structural diagram of another laser projection device provided by an embodiment of the present disclosure;

[0056] Figure 3 is a flow chart of a laser projection method provided by an embodiment of the present disclosure;

[0057] Figure 4 is a flow chart of another laser projection method provided by an embodiment of the present disclosure;

[0058] Figure 5This is a flowchart provided by an embodiment of the present disclosure for determining a first color target value, a second color target value, and a fourth color target value based on a first color initial value and a second color initial value. DETAILED DESCRIPTION

[0059] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0060] Figure 1 and Figure 2 FIG. 1 is a schematic diagram of the structure of a laser projection device provided by an embodiment of the present disclosure. Figure 1 and Figure 2 As shown, the laser projection device may include a driving circuit 10 , a light source 20 and a light valve 30 .

[0061] The driver circuit 10 may be a digital light processing (DLP) driver chip. The light source 20 may be a laser light source, for example, a blue laser. Alternatively, the light source 20 may be a light source other than a laser light source. For example, the light source 20 may be a light bulb or a light-emitting diode (LED). The light valve 30 may be a digital micro-mirror device (DMD).

[0062] refer to Figure 2 The laser projection device may further include a fluorescent wheel 80 and a color filter wheel 90. The blue laser light generated by the light source 20 is sequentially irradiated onto three different areas of the fluorescent wheel 80, thereby generating three-color light (the three-color light may include yellow fluorescent light, green fluorescent light, and blue laser light). The three-color light sequentially passes through the color filter wheel 90 to generate four-color light, which is sequentially irradiated onto the light valve 30.

[0063] Figure 3 This is a flow chart of a laser projection method provided by an embodiment of the present disclosure. The laser projection method can be applied to Figure 1 and Figure 2 In the driving circuit 10 of the laser projection device shown in FIG. 1 , the laser projection device may further include a light source 20 and a light valve 30. Figure 3 As shown, the method may include:

[0064] Step 301: Receive an image signal of a projected image.

[0065] The image signal may include a first color initial value, a second color initial value, and a third color initial value of each pixel in the projected image. The first color initial value, the second color initial value, and the third color initial value of each pixel may be represented by an 8-bit digital signal.

[0066] Optionally, the first color may be red, the second color may be green, and the third color may be blue. Accordingly, the first color initial value may be represented by R, the second color initial value may be represented by G, and the third color initial value may be represented by B. For example, the first color initial value R may be 100, the second color initial value G may be 120, and the third color initial value B may be 200.

[0067] refer to Figure 1 The driving circuit 10 can be connected to the front-end device 00. When the laser projection device projects and displays the projection image, the front-end device 00 can send the image signal of the projection image to the driving circuit 10. Correspondingly, the driving circuit 10 can receive the image signal of the projection image sent by the front-end device 00. Optionally, the front-end device 00 can be a computer.

[0068] Step 302: Determine a first color target value, a second color target value, a third color target value, and a fourth color target value of each pixel according to the first color initial value, the second color initial value, and the third color initial value of each pixel.

[0069] The sum of the first color target value, the second color target value, the third color target value and the fourth color target value is greater than or equal to the sum of the first color initial value, the second color initial value and the third color initial value.

[0070] Optionally, the fourth color may be yellow. The first color target value may be represented by R1, the second color target value may be represented by G1, the third color target value may be represented by B1, and the fourth color target value may be represented by Y1.

[0071] Step 303 : Control the light valve to flip according to the color of the light from the light source irradiating the light valve, and the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel.

[0072] In the disclosed embodiment, when the color of the light emitted by the light source 20 and directed to the light valve is a first color, the driver circuit 10 can control the light valve to flip according to the first color target value for each pixel. The first color can be red, i.e., the light emitted by the light source 20 and directed to the light valve 30 is red fluorescent light or red laser light. After determining the first color target value R1, the driver circuit 10 controls the light valve 30 to flip according to the first color target value R1 for each pixel when the color of the light emitted by the light source 20 and directed to the light valve 30 is red.

[0073] The flipping time of the light valve 30 is positively correlated with the first color target value R1 , and the illumination intensity of the red fluorescent light or red laser light finally projected onto the projection screen is positively correlated with the first color target value R1 .

[0074] When the color of the light emitted by the light source 20 and directed to the light valve is the second color, the driver circuit 10 may control the light valve to flip according to the second color target value for each pixel. Optionally, the second color may be green, i.e., the light emitted by the light source 20 and directed to the light valve 30 is green fluorescent light or green laser light. After determining the second color target value G1, the driver circuit 10 controls the light valve 30 to flip according to the second color target value G1 for each pixel when the color of the light emitted by the light source 20 and directed to the light valve 30 is green.

[0075] The flipping time of the light valve 30 is positively correlated with the second color target value G1 , and the illumination intensity of the green fluorescent light or green laser light finally projected onto the projection screen is positively correlated with the second color target value G1 .

[0076] When the color of the light emitted by the light source 20 and directed to the light valve is the third color, the driver circuit 10 may control the light valve to flip according to the third color target value for each pixel. Optionally, the third color may be blue, i.e., the light emitted by the light source 20 and directed to the light valve 30 is blue laser light. After determining the third color target value, the driver circuit 10 controls the light valve 30 to flip according to the third color target value B1 for each pixel when the color of the light emitted by the light source 20 and directed to the light valve 30 is blue.

[0077] The flipping time of the light valve 30 is positively correlated with the third color target value B1 , and the illumination intensity of the blue laser light finally projected onto the projection screen is positively correlated with the third color target value B1 .

[0078] When the color of the light emitted by the light source 20 and directed to the light valve is the fourth color, the driver circuit 10 may control the light valve to flip according to the fourth color target value for each pixel. Optionally, the fourth color may be yellow, i.e., the light emitted by the light source 20 and directed to the light valve 30 is yellow. After determining the fourth color target value, the driver circuit 10 controls the light valve 30 to flip according to the fourth color target value B1 for each pixel when the color of the light emitted by the light source 20 and directed to the light valve 30 is yellow.

[0079] The flipping time of the light valve 30 is positively correlated with the fourth color target value Y1 , and the illumination intensity of the yellow light finally projected onto the projection screen is positively correlated with the fourth color target value Y1 .

[0080] In summary, the embodiments of the present disclosure provide a laser projection method that can determine a first color target value, a second color target value, a third color target value, and a fourth color target value for each pixel in a projected image based on the first color initial value, the second color initial value, and the third color initial value of the pixel. The light valve flipping is controlled based on the color of the light emitted by the light source to the light valve, as well as the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel. The embodiments of the present disclosure increase the color light generated by the light source, determine the color target values ​​corresponding to the four colors of light based on the color initial values ​​of the three colors of each pixel in the projected image, and control the flipping of the light valve based on the color target values ​​corresponding to the four colors of light, thereby integrating the increased color light into the displayed projected image. This improves the brightness of the displayed image compared to the related art that merely projects three colors of light to achieve image display.

[0081] Figure 4 This is a flow chart of another laser projection method provided by an embodiment of the present disclosure. The laser projection method can be applied to Figure 1 and Figure 2 In the driving circuit 10 of the laser projection device shown in FIG. 1 , the laser projection device may further include a light source 20 and a light valve 30. Figure 4 As shown, the method may include:

[0082] Step 401: Receive an image signal of a projected image.

[0083] The image signal may include a first color initial value, a second color initial value, and a third color initial value of each pixel in the projected image. Optionally, the first color initial value, the second color initial value, and the third color initial value of each pixel may be represented by an 8-bit digital signal.

[0084] The present disclosure is described using the example of a first color being red, a second color being green, and a third color being blue. The first color initial value can be represented by R, the second color initial value can be represented by G, and the third color initial value can be represented by B. For example, the first color initial value R can be 100, the second color initial value G can be 120, and the third color initial value B can be 200.

[0085] refer to Figure 1 The driving circuit 10 can be connected to the front-end device 00. When the laser projection device projects and displays the projection image, the front-end device 00 can send the image signal of the projection image to the driving circuit 10. Correspondingly, the driving circuit 10 can receive the image signal of the projection image sent by the front-end device 00. For example, the front-end device can be a computer.

[0086] Step 402: Detect whether the first color initial value, the second color initial value, and the third color initial value meet the target condition.

[0087] In the embodiment of the present disclosure, after receiving the image signal of the projected image, the driving circuit 10 can detect whether the first color initial value R, the second color initial value G, and the third color initial value B of each pixel in the image signal meet the target condition. If the first color initial value R, the second color initial value G, and the third color initial value B do not meet the target condition, it indicates that the color presented by the pixel in the projected image is not a pure color, and color mixing is required, and step 403 is executed. If the first color initial value R, the second color initial value G, and the third color initial value B do not meet the target condition, it indicates that the color presented by the pixel in the projected image is a pure color, and steps 405 and 406 can be executed.

[0088] The target condition may include one or more of the following conditions:

[0089] (1) The target color initial value among the first color initial value, the second color initial value, and the third color initial value is the color upper limit value, and the other color initial values ​​except the target color initial value are the color lower limit values. Optionally, the color upper limit value K1 can be 255, and the color lower limit value K2 can be 0.

[0090] For example, if the target color value is the first color initial value R, that is, the first color initial value is 255, the second color initial value G is 0, and the third color initial value B is 0, it indicates that the color presented by the pixel in the projected image is 100% pure red.

[0091] If the target color value is the second color initial value G, that is, the second color initial value G can be 255, the first color initial value R is 0, and the third color initial value B is 0, it indicates that the color presented by the pixel in the projected image is 100% pure green.

[0092] If the target color value is the third color initial value B, that is, the third color initial value B is 255, the first color initial value R is 0, and the second color initial value G can be 0, it indicates that the color presented by the pixel in the projected image is 100% pure blue.

[0093] (2) The first color initial value, the second color initial value, and the third color initial value are all color upper limit values.

[0094] For example, if the first color initial value R of a pixel is 255, the second color initial value G is 255, and the third color initial value B is 255, it indicates that the color presented by the pixel in the projected image is 100% pure white.

[0095] Step 403: Determine whether the third color target value is equal to the third color initial value.

[0096] In the embodiment of the present disclosure, after determining that the first color initial value R, the second color initial value G, and the third color initial value B do not meet the target condition, the driving circuit 10 may determine that the third color target value B1 is equal to the third color initial value B, where B1 = B. For example, if the third color initial value B is 200, then the third color target value B1 may be determined to be 200.

[0097] Step 404: Determine a first color target value, a second color target value, and a fourth color target value according to the first color initial value and the second color initial value.

[0098] In the disclosed embodiment, after determining that the first color initial value R, the second color initial value G, and the third color initial value B do not meet the target condition, the driver circuit 10 can determine a first color target value R1, a second color target value G1, and a fourth color target value Y1 based on the first color initial value and the second color initial value. The fourth color can be yellow, and the fourth color value can be represented by Y1. Since red and green light mix to form yellow light, the color target value of red fluorescence and the color target value of green light can be expressed by the color target value of yellow light. The red light can be red fluorescence or red laser. The green light can be green fluorescence or green laser. The yellow light can be yellow fluorescence.

[0099] Optional, such as Figure 5 As shown, step 404 may include:

[0100] Step 4041: Detect whether the initial value of the first color is greater than a first threshold, and whether the initial value of the second color is greater than a second threshold.

[0101] In the embodiment of the present disclosure, after determining that the first color initial value R, the second color initial value G, and the third color initial value B do not meet the target conditions, the driving circuit 10 can respectively detect whether the first color initial value R is greater than the first threshold value X1, and whether the second color initial value G is greater than the second threshold value X2. If the first color initial value R is greater than the first threshold value X1, and the second color initial value G is less than or equal to the second threshold value X2. Alternatively, the first color initial value R is less than or equal to the first threshold value X1, and the second color initial value G is greater than the second threshold value X2. Alternatively, the first color initial value R is less than or equal to the first threshold value X1, and the second color initial value G is less than or equal to the second threshold value X2, then step 4042 is executed. If the first color initial value R is greater than the first threshold value X1, and the second color initial value G is greater than the second threshold value X2, indicating that the color target value of the yellow light cannot fully express the first color initial value R and the second color initial value G, then step 4047 can be executed.

[0102] The first threshold value X1 and the second threshold value X2 may be fixed values ​​pre-stored in the driving circuit 10. The first threshold value X1 represents the limit value of the initial color value of red light that can be expressed by the color target value of yellow light. The second threshold value X2 represents the limit value of the initial color value of green light that can be expressed by the color target value of yellow light.

[0103] For example, the first threshold X1 may be 141.7, and the second threshold X2 may be 115.9.

[0104] Step 4042: Compare the first ratio and the second ratio.

[0105] When the driving circuit determines that the first color initial value R is not greater than the first threshold and the second color initial value G is not greater than the second threshold, the first ratio N1 and the second ratio N2 may be compared. If the first ratio N1 is equal to the second ratio N2, indicating that the target color value of the yellow light can fully express the first color initial value R and the second color initial value G, step 4043 may be executed. If the first ratio N1 is less than the second ratio N2, indicating that the target color value of the yellow light can fully express the first color initial value R but cannot fully express the second color initial value G, step 4044 may be executed. If the first ratio N1 is greater than the second ratio N2, indicating that the target color value of the yellow light can fully express the second color initial value G but cannot fully express the first color initial value R, step 4045 may be executed.

[0106] The first ratio N1 can be the ratio of the first color initial value R to the second color initial value G, that is, N1= The second ratio N2 is the ratio of the first threshold value X1 to the second threshold value X2, that is, N2= .

[0107] For example, if the first threshold X1 is 141.7 and the second threshold X2 is 115.9, then N2= =1.2226.

[0108] Step 4043: Determine that the first color target value is equal to the color lower limit value, determine that the second color target value is equal to the color lower limit value, and determine that the fourth color target value is equal to the product of the third ratio and the color upper limit value.

[0109] In the embodiment of the present disclosure, when the driving circuit 10 determines that the first ratio N1 is equal to the second ratio N2, it can determine that the color target value of the yellow light can fully express the first color initial value R and the second color initial value G, and therefore it can be determined that the first color target value R1 is equal to the color lower limit value K2, where R1=K2, the second color target value G1 is equal to the color lower limit value K2, where G1=K2, and the fourth color target value Y1 is equal to the third ratio N3×color upper limit value K1, where Y1=N3×K1.

[0110] The third ratio N3 is the ratio of the first color initial value R to the first threshold value X1. Or the third ratio N3 is the ratio of the second color initial value G to the second threshold value X2. = .

[0111] For example, assuming that the first color initial value R is 14.17, the second color initial value G is 11.59, the first threshold X1 is 141.7, the second threshold X2 is 115.9, the color upper limit K1 is 255, and the color lower limit K2 is 0, then the first ratio N1= = =1.2226, the second ratio N2= =1.2226, the third ratio N3= = =0.1. Since N1=N2, the driving circuit 10 can determine the first color target value R1=0, the second color target value G1=0, and the fourth color target value Y1=N3×255=0.1×255=25.5.

[0112] Step 4044: Determine that the first color target value is equal to the color lower limit value, determine that the fourth color target value is equal to the product of the fourth ratio and the color upper limit value, and determine that the second color target value is equal to the product of the fifth ratio and the color upper limit value.

[0113] In the embodiment of the present disclosure, after determining that the first ratio N1 is less than the second ratio N2, the driving circuit 10 can determine that the color target value of the yellow light can fully express the first initial color value R, but cannot fully express the second initial color value G. Therefore, the driving circuit 10 can determine that the first color target value R1 is equal to the color lower limit value K2, where R1=K2, determine that the fourth color target value Y1 is equal to the product of the fourth ratio N4 and the color upper limit value K1, where Y1=N4×K1, and determine that the second color target value G1 is equal to the product of the fifth ratio N5 and the color upper limit value K1, where G1=N5×K1.

[0114] The fourth ratio N4 is the ratio of the first color initial value R to the first threshold value X1, and N4= The fifth ratio N5 is the ratio of the first difference d1 to the second difference d2, the first difference d1 is the difference between the second color initial value G and the product of the fourth ratio N4 and the second threshold value X2, the second difference d2 is the difference between the color upper limit value K1 and the second threshold value X2, the N5= = The second difference d2 is a limit value of the initial color value of the red light that can be expressed by the color target value of the red light.

[0115] For example, assuming that the first color initial value R is 100, the second color initial value G is 120, the first threshold value X1 is 141.7, the second threshold value X2 is 115.9, the color upper limit value is 255, and the color lower limit value is 0, the driving circuit 10 can determine the first ratio N1= = =0.83, the second ratio N2= =1.2226, the fourth ratio N4= = =0.7057, the fifth ratio N5= = = =0.2747. Since the first ratio N1=0.83 is less than the second ratio N2=1.2226, the driving circuit 10 can determine the first color target value R1=0, the fourth color target value Y1=N4×255=0.7057×255=180, and the second color target value G1=N5×K1=0.2747×255=70.

[0116] Step 4045: Determine that the second color target value is equal to the color lower limit value, determine that the fourth color target value is equal to the product of the sixth ratio and the color upper limit value, and determine that the first color target value is equal to the product of the seventh ratio and the color upper limit value.

[0117] In the embodiment of the present disclosure, after determining that the first ratio N1 is greater than the second ratio N2, the driving circuit 10 can determine that the color target value of the yellow light can fully express the second color initial value G, but cannot fully express the first color initial value R, then the second color target value G1 can be determined to be the color lower limit value K2, where G1=K2, and the fourth color target value Y1 is determined to be equal to the product of the sixth ratio N6 and the color upper limit value K1, where Y1=N6×K1, and the first color target value R1 is determined to be equal to the product of the seventh ratio N7 and the color upper limit value K1, where R1=N7×K1.

[0118] The sixth ratio N6 is the ratio of the second color initial value G to the second threshold value X2, and N6= The seventh ratio N7 is the ratio of the third difference d3 to the fourth difference d4, the third difference d3 is the difference between the first color initial value R and the product of the sixth ratio N6 and the first threshold value X1, the fourth difference d4 is the difference between the color upper limit value K1 and the first threshold value X1, the N7= = The fourth difference is a limit value of the initial color value of the green light that can be expressed by the color target value of the green light.

[0119] For example, assuming that the first color initial value R is 130, the second color initial value G is 100, the first threshold value X1 is 141.7, the second threshold value X2 is 115.9, the color upper limit value is 255, and the color lower limit value is 0, the driving circuit 10 can determine the first ratio N1= = =1.3, the second ratio N2= =1.2226, the sixth ratio N6= = =0.8628. The seventh ratio N7= = = =0.0683. Since the first ratio N1=1.3 is greater than the second ratio N2=1.2226, the driving circuit 10 can determine the second color target value G1=0, the fourth color target value Y1=N6×K1=0.8628×255=220, and the first color target value R1=N7×K1=0.0683×255=17.

[0120] Step 4046: Determine that the fourth color target value is the color upper limit value, determine that the first color target value is equal to the product of the eighth ratio and the color upper limit value, and determine that the second color target value is equal to the product of the ninth ratio and the color upper limit value.

[0121] When the driving circuit 10 determines that the first color initial value R is greater than the first threshold value X1 and the second color initial value G is greater than the second threshold value X2, it can determine that the color target value of the yellow light cannot fully express the second color initial value G and the first color initial value R. The driving circuit 10 can then determine that the fourth color target value Y1 is equal to the color upper limit value K1, where Y1 = K1. The first color target value R1 is determined to be equal to the product of the eighth ratio N8 and the color upper limit value K1, where R1 = N8 × K1. The second color target value G1 is determined to be equal to the product of the ninth ratio N9 and the color upper limit value K1, where G1 = N9 × K1.

[0122] The eighth ratio N8 is the ratio of the difference between the first color initial value R and the first threshold value X1 to the fourth difference d4. N8= The ninth ratio N9 is the ratio of the difference between the second color initial value G and the second threshold value X2 to the second difference d2. N9= .

[0123] For example, assuming that the first color initial value R is 150, the second color initial value G is 120, the first threshold value X1 is 141.7, the second threshold value X2 is 115.9, the color upper limit value K1 is 255, and the color lower limit value K2 is 0, then the eighth ratio N8= = = =0.0733, the ninth ratio N9= = = =0.0072. Since the first color initial value R=150 is greater than the second color initial value G=120, the driving circuit 10 can determine the fourth color value Y1=255, determine the first color target value R1=N8×255=0.0733×255=19, and determine the second color target value G1=N9×255=0.0072×255=2.

[0124] In the embodiment of the present disclosure, after color mixing, the sum of the first color target value R1, the second color target value G1, the third color target value B1 and the fourth color target value Y1 is greater than the sum of the first color initial value R, the second color initial value G and the third color initial value B, that is, R1+G1+B1+Y1>R+G+B.

[0125] For example, if the first color initial value R is 150, the second color initial value G is 120, and the third color initial value B1 is 200, the driving circuit 10 can determine the first color target value R1=19, the second color target value G1=2, the third target value B1=200 and the fourth color target value Y1=255 by executing the above steps 403 and 404. R1+G1+B1+Y1=19+2+200+255=476, and R+G+B=150+120+200=470. Since 476>470, it can be seen that R1+G1+B1+Y1>R+G+B.

[0126] Step 405 : Determine that the color target value corresponding to the target color initial value is equal to the color upper limit value, and determine that the color target values ​​other than the color target value corresponding to the target color initial value are equal to the color lower limit value.

[0127] In the embodiment of the present disclosure, if the target color initial value among the first color initial value R, the second color initial value G, and the third color initial value B is determined to be the color upper limit value, and the color initial values ​​other than the target color initial value are the color lower limit values, the driving circuit 10 may determine that the color target value corresponding to the target color initial value is equal to the color upper limit value K1, and determine that the color target values ​​other than the color target value corresponding to the target color initial value are equal to the color lower limit value K2. The target color initial value may be any one of the first color initial value R, the second color initial value G, and the third color initial value B.

[0128] For example, assuming that the color upper limit value K1 is 255 and the color lower limit value K2 is 0. If the target color initial value is the first color initial value R, the driving circuit 10 can determine the first color target value R1=255, the second color target value G1=0, the third color target value B1=0, and the fourth color target value Y1=0.

[0129] If the target color value is the second color initial value G, the driving circuit 10 may determine the second color target value G1=255, the first color target value R1=0, the third color target value B1=0, and the fourth color target value Y1=0.

[0130] If the target color value is the third color initial value B, the driving circuit 10 may determine the third color target value B1=255, the first color target value R1=0, the second color target value G1=0, and the fourth color target value Y1=0.

[0131] In an embodiment of the present disclosure, if the color presented by the pixel in the projected image is pure red, pure green or pure blue, then the sum of the first color target value, the second color target value, the third color target value and the fourth color target value is equal to the sum of the first color initial value, the second color initial value and the third color initial value.

[0132] Step 406: Determine whether the first color target value, the second color target value, the third color target value, and the fourth color target value are all equal to the color upper limit value.

[0133] In the embodiment of the present disclosure, if the first color initial value R, the second color initial value G, and the third color initial value B are all determined to be the color upper limit value K1, the driving circuit 10 can determine that the first color target value R1 is equal to the color upper limit value K1, where R1 = K1. The second color target value G1 is determined to be equal to the color upper limit value K1, where G1 = K1. The third color target value B1 is determined to be equal to the color upper limit value K1, where B1 = K1. The fourth color target value Y1 is determined to be equal to the color upper limit value K1, where Y1 = K1.

[0134] For example, assuming that the color upper limit value K1 is 255, the first color initial value R, the second color initial value G and the third color initial value B are all the color upper limit value K1, then the driving circuit 10 can determine the first color target value R1=255, determine the second color target value G1=255, determine the third color target value B1=255, and determine the fourth color target value Y1=255.

[0135] Among them, if the color presented by the pixel in the projected image is pure white, the sum of the first color target value, the second color target value, the third color target value and the fourth color target value is greater than the sum of the first color initial value, the second color initial value and the third color initial value.

[0136] Step 407 : Control the light valve to flip according to the color of the light from the light source irradiating the light valve, and the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel.

[0137] In the embodiment of the present disclosure, the driving circuit 10 can control the flipping of the light valve according to the color of the light irradiated to the light valve by the light source, and the first color target value, second color target value, third color target value and fourth color target value of the pixel.

[0138] Optionally, when the color of the light emitted by the light source to the light valve is a first color, the driving circuit 10 can control the light valve to flip according to the first color target value of each pixel. The first color is red, that is, the light emitted by the light source 20 to the light valve 30 is red fluorescent light r or red laser light r. Figure 1After determining the first color target value R1 for each pixel in the projected image, the driver circuit 10 may send a driving signal to the light valve 30. This driving signal may carry the first color target value R1 for each pixel. When the color of the light emitted by the light source 20 to the light valve 30 is the first color, the light valve 30 may flip according to the first color target value R1 for each pixel.

[0139] The flipping duration of the light valve 30 is positively correlated with the magnitude of the first color target value R1, and the intensity of the red fluorescent light or red laser light ultimately projected onto the projection screen is also positively correlated with the magnitude of the first color target value R1. That is, the larger the first color target value R1, the longer the flipping duration of the light valve 30, and accordingly, the higher the intensity of the red fluorescent light r or red laser light ultimately projected onto the projection screen. By controlling the flipping duration of the light valve 30 using the first color target value R1, the intensity of the red fluorescent light r or red laser light ultimately projected onto the projection screen is controlled, thereby controlling the display intensity of the red component of each pixel in the image ultimately projected onto the projection screen.

[0140] The light valve 30 is integrated with multiple lenses, each corresponding to a pixel in the projected image. These lenses simultaneously project the same color of light. When light shines on the light valve, each lens flips based on the first color target value R1 of the corresponding pixel, projecting the corresponding pixel's red fluorescent light r or red laser light r onto the projection screen.

[0141] refer to Figure 1 and Figure 2 The laser projection device may further include a laser driving assembly 40 connected to the driving assembly 10, a beam shaping assembly 50, a light combining assembly 60, a reflection assembly 70, a fluorescent wheel 80, a color filter wheel 90, a light rod 100, a lens assembly 110, a total internal reflection (TIR) ​​lens 120, a projection lens 130 and a projection screen 140.

[0142] The laser driver assembly 40 is connected to the light source 20, which is a blue laser. The reflective assembly 70 may include a first reflector 701, a second reflector 702, and a third reflector 703. The light combining assembly 60 may be a dichroic filter. The light rod 100 may also be referred to as a light guide.

[0143] In the embodiment of the present disclosure, after receiving the image signal of the projected image, the driver circuit 10 can output an enable signal EN and a current control signal corresponding to the projected image, and transmit the enable signal and the current control signal to the laser driver component 40. The current control signal can be a pulse width modulation (PWM) signal. In response to the received enable signal EN and current control signal, the laser driver component 40 can provide a corresponding drive current to the blue laser connected to it. The blue laser can emit light under the drive current provided by the laser driver component 40.

[0144] refer to Figure 2 The blue laser light emitted by the light source 20 (i.e., a blue laser) is focused by the beam shaping assembly 50 and reflected by the light combining assembly 60. It then projects onto the yellow phosphor area of ​​the phosphor wheel 80, stimulating yellow fluorescence. This yellow fluorescence, after being reflected by the metal substrate of the phosphor wheel 80, passes through the light combining assembly 60 again and is filtered by the color filter wheel 90 to produce red fluorescence r. This red fluorescence r is homogenized by the light rod 100 and shaped by the lens assembly 110 before entering the TIR lens 120. After total internal reflection by the TIR lens 120, this red fluorescence r is irradiated onto the light valve 30. The light valve 30 flips according to the first color target value R1 for each pixel to reflect the red fluorescence r. The red fluorescence r then passes through the TIR lens 120 again and is projected onto the projection screen 140 through the projection lens 130.

[0145] Optionally, when the color of the light emitted by the light source to the light valve is a second color, the driving circuit 10 can control the light valve to flip according to the second color target value of each pixel. The second color is green, that is, the light emitted by the light source 20 to the light valve 30 is green fluorescent light g or green laser light g. Figure 1 After determining the second color target value G1, the driver circuit 10 may send a driving signal to the light valve 30. The driving signal may include the second color target value G1 for each pixel. When the color of the light emitted by the light source 20 to the light valve 30 is the second color, the light valve 30 may flip according to the second color target value G1 for each pixel.

[0146] The flipping duration of the light valve 30 is positively correlated with the magnitude of the second color target value G1, and the intensity of the green fluorescent light or green laser light ultimately projected onto the projection screen is also positively correlated with the magnitude of the second color target value G1. That is, the larger the second color target value G1, the longer the flipping duration of the light valve 30, and accordingly, the higher the intensity of the green fluorescent light g or green laser light g ultimately projected onto the projection screen. In other words, by controlling the flipping duration of the light valve 30 based on the second color target value G1, the intensity of the green fluorescent light g or green laser light g ultimately projected onto the projection screen is controlled, thereby controlling the display intensity of the green component of each pixel in the image ultimately projected onto the projection screen.

[0147] Optionally, after the light source irradiates the light valve, each lens may be flipped according to the second color target value G1 of the corresponding pixel, thereby projecting the green fluorescence g or green laser g of the corresponding pixel onto the projection screen.

[0148] refer to Figure 1 and Figure 2 The blue laser light emitted by the light source 20 (a blue laser) is focused by the beam shaping assembly 50 and reflected by the light combining assembly 60 before being projected onto the green phosphor area of ​​the phosphor wheel 80, thereby stimulating green fluorescence. This green fluorescence light is reflected by the metal substrate of the phosphor wheel 80, passes through the light combining assembly 60 again, and is filtered by the color filter wheel 90 to produce green fluorescence light g. This green fluorescence light g is homogenized by the light rod 100 and shaped by the lens assembly 110 before entering the TIR lens 120. After being totally reflected by the TIR lens 120, this green fluorescence light g is irradiated onto the light valve 30. The light valve 30 flips according to the second color target value G1 for each pixel to reflect the green fluorescence light g. This green fluorescence light g then passes through the TIR lens 120 again and is projected onto the projection screen 140 through the projection lens 130.

[0149] Optionally, when the color of the light emitted by the light source 20 to the light valve is a third color, the driver circuit 10 may control the light valve to flip based on the third color target value for each pixel. The third color is blue, meaning that the light emitted by the light source 20 to the light valve 30 is blue laser light b. After determining the third color target value B1, the driver circuit 10 may send a drive signal to the light valve 30. This drive signal may include the second color target value B1 for each pixel. When the color of the light emitted by the light source 20 to the light valve 30 is the third color, the light valve 30 may flip based on the third color target value B1 for each pixel.

[0150] The flipping duration of the light valve 30 is positively correlated with the magnitude of the third color target value B1, and the intensity of the blue laser light ultimately projected onto the projection screen is also positively correlated with the magnitude of the third color target value B1. That is, the larger the third color target value B1, the longer the flipping duration of the light valve 30, and accordingly, the higher the intensity of the blue laser light ultimately projected onto the projection screen. By controlling the flipping duration of the light valve 30 using the third color target value B1, the intensity of the blue laser light ultimately projected onto the projection screen is controlled, thereby controlling the display intensity of the blue component of each pixel in the image ultimately projected onto the projection screen.

[0151] Optionally, after the light source 20 irradiates the light valve 30 , each lens may be flipped according to the third color target value B1 of the corresponding pixel, thereby projecting the blue laser light of the corresponding pixel onto the projection screen.

[0152] refer to Figure 1 and Figure 2 The blue laser light emitted by light source 20 (a blue laser) is focused by beam shaping assembly 50 and reflected by light combining assembly 60. It then passes through the transparent area of ​​phosphor wheel 80, sequentially reflects off first reflector 701, second reflector 702, and third reflector 703, and then reflects again from light combining assembly 60. It then passes through the transparent area of ​​color filter wheel 90 to produce blue laser light b. This blue laser light b is homogenized by light rod 100 and shaped by lens assembly 110 before entering TIR lens 120. After total internal reflection from TIR lens 120, this blue laser light b is irradiated by light valve 30, which flips to reflect the blue laser light b based on the third color target value B1 for each pixel. This blue laser light b then passes through TIR lens 120 again and is projected onto projection screen 140 through projection lens 130.

[0153] Optionally, when the color of the light emitted by the light source to the light valve is a fourth color, the driving circuit 10 can control the light valve to flip according to the fourth color target value of each pixel. The fourth color is yellow, that is, the light emitted by the light source 20 to the light valve 30 is yellow fluorescent light y. Figure 1 After determining the fourth color target value Y1, the driver circuit 10 may send a driving signal to the light valve 30. The driving signal may carry the fourth color target value Y1 for each pixel. When the color of the light emitted by the light source 20 to the light valve 30 is the fourth color, the light valve 30 may flip according to the fourth color target value Y1 for each pixel.

[0154] The flipping duration of the light valve 30 is positively correlated with the magnitude of the fourth color target value Y1, and the intensity of the yellow fluorescent light ultimately projected onto the projection screen is also positively correlated with the magnitude of the fourth color target value Y1. That is, the larger the fourth color target value Y1, the longer the flipping duration of the light valve 30, and accordingly, the higher the intensity of the yellow fluorescent light ultimately projected onto the projection screen. In other words, by controlling the flipping duration of the light valve 30 based on the fourth color target value Y1, the intensity of the yellow fluorescent light ultimately projected onto the projection screen is controlled, thereby controlling the display intensity of the red and green components of each pixel in the image ultimately projected onto the projection screen.

[0155] Optionally, after the light source 20 irradiates the light valve 30 , each lens may be flipped according to the fourth color target value Y1 of the corresponding pixel, thereby projecting the yellow fluorescence y of the corresponding pixel onto the projection screen.

[0156] refer to Figure 1 and Figure 2 The blue laser light emitted by light source 20 (a blue laser) is focused by beam shaping assembly 50 and reflected by light combining assembly 60. It then strikes the yellow phosphor area of ​​phosphor wheel 80, stimulating yellow fluorescence. This yellow fluorescence is reflected by the metal substrate of phosphor wheel 80, passes through light combining assembly 60 again, and passes through the transparent area of ​​color filter wheel 90 to produce yellow fluorescence y. This yellow fluorescence y is homogenized by light rod 100 and shaped by lens assembly 110 before entering TIR lens 120. After total internal reflection by TIR lens 120, this yellow fluorescence y is irradiated by light valve 30. Light valve 30 flips the light according to the fourth color target value Y1 for each pixel to reflect the yellow fluorescence y. This yellow fluorescence y then passes through TIR lens 120 again and is projected onto projection screen 140 through projection lens 130.

[0157] The red fluorescent light r, the green fluorescent light g, the blue laser light b, and the yellow fluorescent light y are sequentially projected onto the projection screen 140 through the projection lens 130 , thereby displaying the projection image on the projection screen 140 .

[0158] In the embodiment of the present disclosure, by increasing the color light generated by the light source, the color target values ​​corresponding to the four-color light are determined based on the color initial values ​​of the three colors of each pixel in the projected image, and the flipping duration of the light valve is controlled based on the color target values ​​corresponding to the four-color light to control the cumulative time of the light source input into the projection lens, thereby realizing the use of the four-color light and the three colors of the image, thereby integrating the increased color light into the displayed projected image.

[0159] In the embodiment of the present disclosure, assuming that the frequency of the fluorescent wheel 80 and the color filter wheel 90 is H Hertz (HZ), one cycle is T, where T= The rotation angle of the fluorescent wheel 80 and the color filter wheel 90 in one cycle is Y. Then, in one cycle, when the light source 20 passes through the fluorescent wheel 80 and the color filter wheel 90 to generate red fluorescence r, the maximum angle that the fluorescent wheel 80 and the color filter wheel 90 can rotate is the first angle y1. When the red fluorescence irradiates the light valve 30, the maximum flipping time of the light valve 30 is T1, where T1 = It can be seen from this that when the light valve 30 is flipped according to the first color target value R1, its flipping time is t1, which is t1 = × T1. The maximum flipping time T1 of the light valve 30 is positively correlated with the first angle y1.

[0160] For example, when the first color initial value R of a pixel in the image signal is 255, the second color initial value G is 0, and the third color initial value B is 0, that is, the pixel appears to be 100% pure red in the projected image, and the grayscale ratio is reduced year by year. The first angle y1 can be 80, at which time the light intensity of the red fluorescent light projected onto the projection screen is the highest.

[0161] When the light source 20 generates green fluorescence g through the fluorescent wheel 80 and the color filter wheel 90 in one cycle, the maximum angle that the fluorescent wheel 80 and the color filter wheel 90 can rotate is the second angle y2. When the green fluorescence g irradiates the light valve 30, the maximum flipping time of the light valve 30 is T2, where T2= It can be seen from this that when the light valve 30 is flipped according to the second color target value G1, its flipping time is t2, which is t2 = × T2. The maximum flipping time T2 of the light valve 30 is positively correlated with the second angle y2.

[0162] For example, when the first color initial value R of a pixel in the image signal is 0, the second color initial value G is 255, and the third color initial value B is 0, that is, the pixel appears to be 100% pure green in the projected image, and the grayscale ratio is reduced year by year. The second angle y2 can be 120, at which time the light intensity of the green fluorescent light projected onto the projection screen is the highest.

[0163] When the light source 20 generates blue laser light b through the fluorescent wheel 80 and the color filter wheel 90 in one cycle, the maximum angle that the fluorescent wheel 80 and the color filter wheel 90 can rotate is the third angle y3. When the blue laser light b irradiates the light valve 30, the maximum flipping time of the light valve 30 is T3, where T3 = It can be seen from this that when the light valve 30 is flipped according to the third color target value B1, its flipping time is t3, which is t3 = × T3. The maximum flipping time T3 of the light valve 30 is positively correlated with the third angle y3.

[0164] For example, when the first color initial value R of a pixel in the image signal is 0, the second color initial value G is 0, and the third color initial value B is 255, that is, the pixel appears to be 100% pure blue in the projected image, and the third angle y3 can be 60 according to the grayscale ratio.

[0165] When the light source 20 generates yellow fluorescence y through the fluorescent wheel 80 and the color filter wheel 90 in one cycle, the maximum angle that the fluorescent wheel 80 and the color filter wheel 90 can rotate is the fourth angle y4. When the yellow fluorescence y irradiates the light valve 30, the maximum flipping time of the light valve 30 is T4, where T4= It can be seen from this that when the light valve 30 is flipped according to the fourth color target value Y1, its flipping time is t4, which is t4 = × T4. The maximum flipping time T4 of the light valve 30 is positively correlated with the fourth angle y4.

[0166] For example, when the first color initial value R of a pixel in the image signal is 255, the second color initial value G is 255, and the third color initial value B is 255, that is, the pixel appears to be 100% pure white in the projected image, and the fourth angle y4 can be 100 according to the grayscale ratio.

[0167] In the embodiment of the present disclosure, the first angle, the second angle, the third angle and the fourth angle can be set according to the material of the phosphor on the phosphor wheel and specific design requirements.

[0168] For example, assuming that the frequency of the fluorescent wheel and the color filter wheel is H = 120 Hz, that is, T = 8.33 milliseconds (ms), the rotation angle of the fluorescent wheel 80 and the color filter wheel 90 in one cycle is Y = 360 degrees, the first angle y1 is 80, the second angle y2 is 120, the third angle y3 is 60, the fourth angle y4 is 100, and the color upper limit value K1 is 255.

[0169] If the first color target value R1=0, when the red fluorescence r irradiates the light valve 30, the maximum flipping time T1 of the light valve 30= = ×8.33=1.85ms. Therefore, it can be obtained that when the light valve 30 is flipped according to the first color target value R1, its flipping time is t1= ×T1= ×1.85=0ms.

[0170] If the second color target value G1=70, when the green fluorescence g irradiates the light valve 30, the maximum flipping time of the light valve 30 is T2= = × 8.33 = 2.78ms. Therefore, it can be obtained that when the light valve 30 is flipped according to the second color target value G1, its flipping time is t2 = ×T2= ×2.78=0.76ms.

[0171] If the third color target value B1=200, when the blue laser b irradiates the light valve 30, the maximum flipping time of the light valve 30 is T3= = ×8.33=1.39ms. Therefore, when the light valve 30 is flipped according to the third color target value B1, its flipping time is t3= ×T3= ×1.39=1.09ms.

[0172] If the fourth color target value Y1=200, when the yellow fluorescence y irradiates the light valve 30, the maximum flipping time of the light valve 30 is T4= = ×8.33=2.31ms. Therefore, it can be obtained that when the light valve 30 is flipped according to the fourth color target value Y1, its flipping time is t4= ×T4= ×2.31=1.63ms.

[0173] It should be noted that the first threshold X1 is equal to the product of the tenth ratio N10 and the color upper limit K1, X1=N10×K1. The second threshold X2 is equal to the product of the eleventh ratio N11 and the color upper limit K1, X2=N11×K1.

[0174] The tenth ratio N10 is the ratio of the fourth angle y4 to the sum of the first angle y1 and the fourth angle y4. The eleventh ratio N11 is the ratio of the fourth angle y4 to the sum of the second angle y2 and the fourth angle y4, and N11= .

[0175] For example, assuming that the first angle y1 is 80, the second angle y2 is 120, the fourth angle y4 is 100, and the color upper limit value K1=255. Then the first threshold X1= ×255= ×255=141.7. The second threshold value X2= ×255= ×255=115.9.

[0176] It should be noted that in the above step 403, the third color target value B1 can also be equal to × K. In the first step 4044, the fourth color target value Y1 can also be equal to × K1. In the above step 4045, the fourth color target value Y1 can also be equal to ×K1.

[0177] It should be noted that the order of the steps of the laser projection method provided in the embodiments of the present disclosure can be appropriately adjusted, and steps can be deleted as needed. For example, steps 402 and 404 can be deleted as needed, or steps 405 and 406 can be deleted as needed, or any of steps 405 and 406 can be deleted as needed, or steps 4041 to 4046 can be deleted. Any method that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be covered by the scope of protection of this disclosure, and therefore will not be described in detail.

[0178] In summary, the embodiments of the present disclosure provide a laser projection method that can determine a first color target value, a second color target value, a third color target value, and a fourth color target value for each pixel in a projected image based on the first color initial value, the second color initial value, and the third color initial value of the pixel. The light valve flipping is controlled based on the color of the light emitted by the light source to the light valve, as well as the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel. The embodiments of the present disclosure increase the color light generated by the light source, determine the color target values ​​corresponding to the four colors of light based on the color initial values ​​of the three colors of each pixel in the projected image, and control the flipping of the light valve based on the color target values ​​corresponding to the four colors of light, thereby integrating the increased color light into the displayed projected image. This improves the brightness of the displayed image compared to the related art that merely projects three colors of light to achieve image display.

[0179] refer to Figure 1 and Figure 2 The laser projection device includes a driving circuit, a light source, and a light valve. The driving circuit 10 is configured to receive an image signal of a projected image, the image signal including a first color initial value, a second color initial value, and a third color initial value for each pixel in the projected image.

[0180] The driving circuit 10 is also used to determine the first color target value, second color target value, third color target value and fourth color target value of the pixel based on the first color initial value, second color initial value and third color initial value of each pixel, wherein the sum of the first color target value, the second color target value, the third color target value and the fourth color target value is greater than or equal to the sum of the first color initial value, the second color initial value and the third color initial value.

[0181] The driving circuit 10 is further configured to control the flipping of the light valve according to the color of the light irradiated from the light source to the light valve, and the first color target value, the second color target value, the third color target value and the fourth color target value of the pixel.

[0182] Optionally, the driving circuit 10 is further configured to:

[0183] If the first color initial value, the second color initial value, and the third color initial value do not meet the target condition, the third color target value is determined to be equal to the third color initial value.

[0184] A first color target value, a second color target value, and a fourth color target value are determined according to the first color initial value and the second color initial value.

[0185] The target conditions include one or more of the following conditions:

[0186] The target color initial value among the first color initial value, the second color initial value, and the third color initial value is the color upper limit value, and the other color initial values ​​except the target color initial value are the color lower limit values;

[0187] The first color initial value, the second color initial value, and the third color initial value are all color upper limit values.

[0188] Optionally, the driving circuit 10 is further configured to:

[0189] It is respectively detected whether the first color initial value is greater than a first threshold value and whether the second color initial value is greater than a second threshold value.

[0190] If the initial value of the first color is greater than the first threshold and the initial value of the second color is less than or equal to the second threshold; or, the initial value of the first color is less than or equal to the first threshold and the initial value of the second color is greater than the second threshold; or, the initial value of the first color is less than or equal to the first threshold and the initial value of the second color is less than or equal to the second threshold, compare the first ratio with the second ratio.

[0191] If the first ratio is equal to the second ratio, determining that the first color target value and the second color target value are both equal to the color lower limit value, and determining that the fourth color target value is equal to the product of the third ratio and the color upper limit value;

[0192] Among them, the first ratio is the ratio of the first color initial value to the second color initial value, the second ratio is the ratio of the first threshold to the second threshold, the third ratio is the ratio of the first color initial value to the first threshold, or the third ratio is the ratio of the second color initial value to the second threshold.

[0193] Optionally, the driving circuit 10 is further configured to:

[0194] After comparing the first ratio with the second ratio, if the first ratio is smaller than the second ratio, it is determined that the first color target value is equal to the color lower limit value.

[0195] The fourth color target value is determined to be equal to the product of a fourth ratio and the color upper limit value, where the fourth ratio is the ratio of the first color initial value to the first threshold value.

[0196] Determine that the second color target value is equal to the product of the fifth ratio and the color upper limit value, the fifth ratio is the ratio of the first difference to the second difference, the first difference is the difference between the second color initial value and the product of the fourth ratio and the second threshold value, and the second difference is the difference between the color upper limit value and the second threshold value.

[0197] Optionally, the driving circuit 10 is further configured to:

[0198] After comparing the first ratio with the second ratio, if the first ratio is greater than the second ratio, it is determined that the second color target value is equal to the color lower limit value.

[0199] The fourth color target value is determined to be equal to a product of a sixth ratio and a color upper limit value, where the sixth ratio is a ratio of the second color initial value to the second threshold value.

[0200] Determine that the first color target value is equal to the product of the seventh ratio and the color upper limit value, the seventh ratio is the ratio of the third difference to the fourth difference, the third difference is the difference between the first color initial value and the product of the sixth ratio and the first threshold value, and the fourth difference is the difference between the color upper limit value and the first threshold value.

[0201] Optionally, the driving circuit 10 is further configured to:

[0202] After respectively detecting whether the first color initial value is greater than the first threshold and whether the second color initial value is greater than the second threshold, if the first color initial value is greater than the first threshold and the second color initial value is greater than the second threshold, the fourth color target value is determined to be the color upper limit value.

[0203] Determine that the first color target value is equal to the product of the eighth ratio and the color upper limit value, the eighth ratio is the ratio of the difference between the first color initial value and the first threshold value to the fourth difference value, and the fourth difference is the difference between the color upper limit value and the first threshold value.

[0204] Determine that the second color target value is equal to the product of the ninth ratio and the color upper limit value, the ninth ratio is the ratio of the difference between the second color initial value and the second threshold value to the second difference, and the second difference is the difference between the color upper limit value and the second threshold value.

[0205] Optionally, the driving circuit 10 is further configured to:

[0206] When the first color initial value, the second color initial value and the third color initial value meet the target conditions, if the target color initial value among the first color initial value, the second color initial value and the third color initial value is the color upper limit value, and the other color initial values ​​except the target color initial value are the color lower limit values, it is determined that the color target value corresponding to the target color initial value is equal to the color upper limit value, and it is determined that the other color target values ​​except the color target value corresponding to the target color initial value are equal to the color lower limit value.

[0207] If the first color initial value, the second color initial value, and the third color initial value are all color upper limit values, it is determined that the first color target value, the second color target value, the third color target value, and the fourth color target value are all equal to the color upper limit value.

[0208] In summary, the embodiments of the present disclosure provide a laser projection device that can determine the first color target value, second color target value, third color target value, and fourth color target value of each pixel in the projected image based on the first color initial value, second color initial value, and third color initial value of the pixel. The light valve flipping is controlled based on the color of the light emitted by the light source to the light valve, as well as the first color target value, second color target value, third color target value, and fourth color target value of the pixel. The embodiments of the present disclosure increase the color light generated by the light source, determine the color target values ​​corresponding to the four colors of light based on the color initial values ​​of the three colors of each pixel in the projected image, and control the flipping of the light valve based on the color target values ​​corresponding to the four colors of light, thereby integrating the increased color light into the displayed projected image. This improves the brightness of the displayed image compared to the related art that merely projects three colors of light to achieve image display.

[0209] The above description is merely an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A laser projection device, characterized in that: Including light source, light valve and driving circuit, The light source is used to irradiate light of a first color, a second color, a third color and a fourth color toward the light valve; The light valve is used to sequentially receive illumination from the first color, the second color, the third color, and the fourth color; The driving circuit is configured to receive an image signal of a projected image, the image signal including a first color initial value, a second color initial value, and a third color initial value for each pixel in the projected image; and further configured to determine a first color target value, a second color target value, a third color target value, and a fourth color target value for each pixel based on the first color initial value, the second color initial value, and the third color initial value, wherein a sum of the first color target value, the second color target value, the third color target value, and the fourth color target value is greater than a sum of the first color initial value, the second color initial value, and the third color initial value; Wherein, the fourth color target value is determined by the first color initial value and the second color initial value; The driving circuit is further configured to: respectively detecting whether the first color initial value is greater than a first threshold value and whether the second color initial value is greater than a second threshold value; If the first color initial value is greater than the first threshold, and the second color initial value is less than or equal to the second threshold; or, the first color initial value is less than or equal to the first threshold, and the second color initial value is greater than the second threshold; or, the first color initial value is less than or equal to the first threshold, and the second color initial value is less than or equal to the second threshold, compare the first ratio with the second ratio; If the first ratio is equal to the second ratio, determining that the first color target value and the second color target value are both equal to the color lower limit value, and determining that the fourth color target value is equal to the product of the third ratio and the color upper limit value; wherein the color upper limit value is 255 and the color lower limit value is 0; The first ratio is the ratio of the first color initial value to the second color initial value, and the second ratio is the ratio of the first threshold to the second threshold. The third ratio is a ratio of the first color initial value to the first threshold, or the third ratio is a ratio of the second color initial value to the second threshold; The driving circuit is configured to output an enable signal and a current control signal corresponding to the projected image after receiving the image signal of the projected image, and transmit the enable signal and the current control signal to the laser driving component to drive the laser of the corresponding color to emit light, Furthermore, the device is configured to control the flipping of the light valve according to the color of the light emitted by the light source to the light valve, and the first color target value, the second color target value, the third color target value, and the fourth color target value of the pixel.

2. The laser projection device according to claim 1, characterized in that: The driving circuit is a digital light processing driving chip, The driving signal sent by the driving circuit to the light valve carries the first color target value, the second color target value, the third color target value and the fourth color target value of each pixel. The light valve is a DMD, including multiple lenses, each lens corresponding to a pixel in the projected image, and each lens is flipped according to the color target value of the corresponding pixel. The flipping time of the light valve is positively correlated with the size of the corresponding color target value.

3. The laser projection device according to claim 2, characterized in that: The multiple lenses project light of the same color at the same time, and the display intensity of any one color component of the first color, the second color, and the third color of each pixel in the projected image is controlled by the flipping duration of the multiple lenses of the light valve.

4. The laser projection device according to any one of claims 1 to 3, characterized in that: The first color is red, the second color is green, the third color is blue, and the fourth color is yellow.

5. The laser projection device according to claim 4, characterized in that: The laser projection device satisfies at least one of the following conditions: The first color is red fluorescence or red laser; The second color is green fluorescence or green laser; The third color is blue laser; The fourth color is yellow fluorescence.

6. The laser projection device according to claim 1, characterized in that: The driving circuit is further used for: If the first color initial value, the second color initial value, and the third color initial value do not meet the target condition, determining that the third color target value is equal to the third color initial value; determining the first color target value, the second color target value, and the fourth color target value according to the first color initial value and the second color initial value; The target conditions include one or more of the following conditions: The target color initial value among the first color initial value, the second color initial value, and the third color initial value is the color upper limit value, and the other color initial values ​​except the target color initial value are the color lower limit values; The first color initial value, the second color initial value, and the third color initial value are all the color upper limit values.

7. The laser projection device according to claim 1, characterized in that: If the color of the pixel in the projected image is pure white, the sum of the first color target value, the second color target value, the third color target value and the fourth color target value is greater than the sum of the first color initial value, the second color initial value and the third color initial value.

8. The laser projection device according to claim 6 or 7, characterized in that: The first color initial value, the second color initial value, and the third color initial value are represented by 8-bit digital signals.

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