WO2021179908A1 - 激光投影设备 - Google Patents

激光投影设备 Download PDF

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Publication number
WO2021179908A1
WO2021179908A1 PCT/CN2021/077665 CN2021077665W WO2021179908A1 WO 2021179908 A1 WO2021179908 A1 WO 2021179908A1 CN 2021077665 W CN2021077665 W CN 2021077665W WO 2021179908 A1 WO2021179908 A1 WO 2021179908A1
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WIPO (PCT)
Prior art keywords
laser
light
brightness
brightness value
brightness sensor
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Application number
PCT/CN2021/077665
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English (en)
French (fr)
Inventor
崔荣荣
Original Assignee
青岛海信激光显示股份有限公司
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Publication of WO2021179908A1 publication Critical patent/WO2021179908A1/zh

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/20—Lamp housings
    • G03B21/2006—Lamp housings characterised by the light source
    • G03B21/2013—Plural light sources
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/20—Lamp housings
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/20—Lamp housings
    • G03B21/2006—Lamp housings characterised by the light source
    • G03B21/2033—LED or laser light sources
    • G03B21/204—LED or laser light sources using secondary light emission, e.g. luminescence or fluorescence
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/20—Lamp housings
    • G03B21/2053—Intensity control of illuminating light

Definitions

  • This application relates to the field of projection display, and in particular to a laser projection device.
  • the laser projection device may include a laser light source, and the laser light source may include a laser of at least one color.
  • the laser light source may include a blue laser for emitting blue laser light.
  • the laser projection device is a full-color laser projection device, the laser light source may include a blue laser, a red laser for emitting red laser light, and a green laser for emitting green laser light.
  • the laser in the laser projection equipment will be overloaded due to the power density of the laser semiconductor junction exceeding the power density during the process of emitting the laser, and the cavity surface of the laser needs to bear a relatively large optical power density to melt and recrystallize, causing the laser to be melted and recrystallized.
  • the cavity surface of the laser absorbs more heat generated by the light and generates a larger temperature rise, which in turn causes catastrophic optical damage (COD) on the cavity surface of the laser.
  • COD catastrophic optical damage
  • the current and voltage Basically remain unchanged, so it is difficult to detect the above-mentioned faults even by monitoring current and voltage changes. If the COD failure of the laser occurs for a long time, it will eventually cause permanent damage to the laser, and also make the quality of the projection image of the laser projection equipment drastically deteriorated. This also reduces the service life and working reliability of lasers and laser projection equipment.
  • An embodiment of the present application provides a laser projection device, including: a display control circuit, a laser light source, at least one laser driving component, and at least one brightness sensor;
  • the laser light source includes at least one group of lasers corresponding to at least one laser driving component one-to-one;
  • the display control circuit is used to output a primary color enable signal and a primary color current control signal to at least one laser driving component to drive at least one group of lasers to emit light.
  • a brightness value and sending the first brightness value to the display control circuit;
  • the display control circuit is also used to obtain the second brightness value corresponding to the drive current of each laser. If the difference between the second brightness value of the laser and the first brightness value of the laser is greater than the difference threshold, adjust the laser drive corresponding to the laser The current control signal of the component until the difference is less than or equal to the difference threshold.
  • Fig. 1 is a schematic diagram of the output characteristics of a laser provided by the related art when a COD failure occurs in a laser;
  • 2A is a schematic diagram of the circuit principle of a laser projection device provided by an embodiment of the present application.
  • 2B is a schematic diagram of the circuit principle of another laser projection device provided by an embodiment of the present application.
  • FIG. 3 is a schematic structural diagram of another laser projection device provided by an embodiment of the present application.
  • FIG. 4 is a schematic structural diagram of another laser projection device provided by an embodiment of the present application.
  • FIG. 5 is a schematic structural diagram of still another laser projection device provided by an embodiment of the present application.
  • FIG. 6 is a schematic structural diagram of another laser projection device provided by an embodiment of the present application.
  • FIG. 7 is a schematic structural diagram of another laser projection device provided by an embodiment of the present application.
  • FIG. 8 is a schematic structural diagram of another laser projection device provided by an embodiment of the present application.
  • FIG. 9 is a schematic structural diagram of another laser projection device provided by an embodiment of the present application.
  • FIG. 10 is a schematic diagram of the circuit principle of another laser projection device provided by an embodiment of the present application.
  • FIG. 11 is a schematic diagram of the principle of the optical path architecture of a laser projection device provided by an embodiment of the application.
  • FIG. 12 is a schematic diagram of the appearance structure of a laser provided by an embodiment of the application.
  • FIG. 1 is a schematic diagram of the output characteristics of a laser provided by the related art when a COD failure occurs in a laser.
  • the schematic diagram includes a first curve and a second curve.
  • the first curve is a change curve of the drive voltage of the laser
  • the second curve is a change curve of the drive current of the laser.
  • the abscissa in the schematic diagram is the driving current
  • the first ordinate is the light-emitting power of the laser
  • the second ordinate is the driving voltage of the laser.
  • the unit of drive current is ampere (A)
  • the unit of luminous power is milliwatt (mW)
  • the unit of drive voltage is volt (V).
  • the laser has a COD failure.
  • its drive current and drive voltage remain basically unchanged, but the laser's luminous power will suddenly decrease.
  • the electric power that drives the laser to emit light remains unchanged, the light emitted by the laser is mainly absorbed by the cavity surface inside the laser and converted into heat, which causes the cavity surface of the laser to generate a large temperature rise, thereby damaging the cavity surface of the laser. Since only a small part of the laser is emitted from the inside of the laser, the luminous power of the laser will suddenly decrease (that is, the luminous brightness of the laser will decrease).
  • the laser when a COD failure occurs, the laser will work at a higher driving current, but it cannot provide a luminous brightness that matches the driving current. If things go on like this, the laser will be damaged, and the image display effect of the laser projection equipment will be poor.
  • each brightness sensor can detect the first brightness value of a group of lasers.
  • the display control circuit can obtain the second brightness value corresponding to the driving current of each group of lasers, and when it is determined that the difference between the second brightness value of the laser and the first brightness value of the laser is greater than the difference threshold, it is determined that the laser is COD failure. Then the display control circuit can adjust the current control signal of the laser driving component corresponding to the laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the laser.
  • the laser projection device can eliminate the COD failure of the laser in time, reduce the duration of the COD failure of the laser, reduce the damage rate of the laser, and ensure the image display effect of the laser projection device.
  • FIG. 2A is a schematic diagram of the principle of a laser projection device provided by an embodiment of the present application.
  • the laser projection device may include a display control circuit 10, a laser light source 20, a laser driving assembly 30, and a brightness sensor 40.
  • the laser light source 20 may include at least one group of lasers 200 corresponding to the laser driving assembly 30. Wherein, the at least one refers to one or more, and multiple refers to two or more.
  • the at least one group refers to one or more groups, and the multiple groups refers to two or more than two groups, and each group of lasers may include one or more lasers.
  • the laser projection device may include a display control circuit 10, a laser light source 20, at least one laser driving component 30, and at least one brightness sensor 40.
  • the laser light source 20 may include a one-to-one correspondence with the at least one laser driving component 30.
  • At least one set of lasers wherein, the at least one refers to one or more, and multiple refers to two or more.
  • the at least one group refers to one or more groups, and the multiple groups refers to two or more than two groups, and each group of lasers may include one or more lasers.
  • the laser projection device shown in FIG. 2B includes three laser driving components 30 and a brightness sensor 40. Accordingly, the laser light source 20 includes three groups of lasers corresponding to the three laser driving components 30 one-to-one.
  • the three groups of lasers can They are a blue laser 201, a red laser 202, and a green laser 203, respectively.
  • the blue laser 201 is used for emitting blue laser
  • the red laser 202 is used for emitting red laser
  • the green laser 203 is used for emitting green laser.
  • the display control circuit 10 is connected to each laser driving component 30, and is used to output at least one enable signal corresponding to the three primary colors of each frame of the multi-frame display image, and transmit the at least one enable signal to
  • the corresponding laser driving component 30 outputs at least one current control signal corresponding to the three primary colors of each frame of image one-to-one, and transmits the at least one current control signal to the corresponding laser driving component 30 respectively.
  • the display control circuit 10 may be a microcontroller unit (MCU), also called a single-chip microcomputer.
  • the current control signal may be a pulse width modulation (PWM) signal.
  • the display control circuit 10 may output a blue PWM signal B_PWM corresponding to the blue laser 201 based on the blue primary color component of the image to be displayed, and output based on the red primary color component of the image to be displayed corresponding to the red laser 202
  • the red PWM signal R_PWM of the signal to be displayed outputs the green PWM signal G_PWM corresponding to the green laser 203 based on the green primary color component of the image to be displayed.
  • the display control circuit 01 can output the enable signal B_EN corresponding to the blue laser 201 based on the lighting duration of the blue laser 201 in the driving cycle, and output the same as the red laser based on the lighting duration of the red laser 202 in the driving cycle.
  • the enable signal R_EN corresponding to 202 outputs an enable signal G_EN corresponding to the green laser 203 based on the lighting duration of the green laser 203 in the driving period.
  • Each laser driving component 30 is connected to a corresponding group of lasers, and is used to provide a corresponding driving current to the laser connected to it in response to the received enable signal and current control signal.
  • Each group of lasers is used to emit light under the driving of the driving current provided by the corresponding laser driving assembly 30.
  • the blue laser 201, the red laser 202, and the green laser 203 are respectively connected to the corresponding laser driving assembly 30.
  • the laser driving component 30 corresponding to the blue laser 201 can provide a corresponding driving current to the blue laser 201 in response to the blue PWM signal B_PWM and the enable signal B_EN sent by the display control circuit 10.
  • the blue laser 201 is used to emit light under the driving of the driving current.
  • At least one brightness sensor 40 is provided on the light-emitting side of the laser light source 20, and each brightness sensor is connected to the display control circuit 10 for detecting the first brightness value of a group of lasers and sending the first brightness value to the display control circuit 10. .
  • the display control circuit 10 is also used to obtain the second brightness value corresponding to the drive current of each group of lasers. When it is detected that the difference between the second brightness value of the laser and the first brightness value of the laser is greater than the difference within the target time period
  • the threshold value indicates that the brightness of the laser drops sharply, that is, the laser has a COD failure.
  • the display control circuit 10 can adjust the current control signal of the laser drive component 30 corresponding to the laser until the difference is less than or equal to the difference threshold, that is, by reducing
  • the drive current of the laser is used to eliminate the COD failure of the laser.
  • the display control circuit 10 does not need to adjust the laser drive corresponding to the laser Component 30 current control signal.
  • the target duration may be a fixed duration pre-stored in the display control circuit 10.
  • the corresponding relationship between the current and the brightness value may be stored in the display control circuit 10.
  • the brightness value corresponding to each current in the corresponding relationship is the initial brightness value that the laser can emit when the laser works normally under the drive of the current (that is, when no COD failure occurs).
  • the brightness value may be the initial brightness when the laser is first turned on when the laser is driven by the current.
  • the display control circuit 10 can obtain the second brightness value corresponding to the driving current of each group of lasers from the corresponding relationship.
  • the driving current is the current actual working current of the laser
  • the second brightness value corresponding to the driving current is the laser in the driving current.
  • the brightness value that can be emitted during normal operation under the drive of The difference threshold may be a fixed value stored in advance in the display control circuit 10.
  • the current control of the laser driving component 30 corresponding to the laser can be reduced.
  • the duty cycle of the signal thereby reducing the drive current of the laser.
  • the display control circuit 10 is used to maintain the current control signal of the laser drive component corresponding to the laser when it is detected that the difference between the second brightness value of the laser and the first brightness value of the laser is less than or equal to the difference threshold.
  • the duty cycle remains unchanged, that is, the display control circuit 10 provides a reduced current control signal to the laser drive component corresponding to the laser, and keeps the duty cycle of the reduced current control signal unchanged.
  • the laser drive component 30 provides a reduced drive current to the corresponding laser, and the laser emits light under the drive of the reduced drive current, thereby forming a closed-loop automatic adjustment process.
  • the brightness sensor 40 can detect the first brightness value of the blue laser 201 and send the first brightness value to the display control circuit 10.
  • the display control circuit 10 can obtain the driving current of the blue laser 201, and obtain the second brightness value corresponding to the driving current from the corresponding relationship between the current and the brightness value. Afterwards, it is detected whether the difference between the second brightness value and the first brightness value within the target time period is greater than the difference threshold. If the difference is greater than the difference threshold, it indicates that the blue laser 201 has a COD failure, and the display control circuit 10 can reduce the duty cycle of the current control signal of the laser driving component 30 corresponding to the blue laser 201.
  • the display control circuit 10 can obtain the first brightness value of the blue laser 201 and the second brightness value corresponding to the driving current of the blue laser 201 again, and the difference between the second brightness value and the first brightness value is greater than
  • the difference threshold is lowered, the duty cycle of the current control signal of the laser driving assembly 30 corresponding to the blue laser 201 is lowered again.
  • the duty cycle of the current control signal of the laser drive component corresponding to the laser is kept unchanged . Therefore, by reducing the driving current of the blue laser 201, the COD failure of the blue laser 201 is eliminated.
  • the display control circuit 10 can monitor each group of lasers in real time according to the first brightness value of each group of lasers acquired by at least one brightness sensor 40 and the second brightness value corresponding to the driving current of each group of lasers. Whether a COD failure has occurred. When it is determined that any group of lasers has a COD failure, the COD failure of the laser is eliminated in time, the duration of the COD failure of the laser is reduced, the damage of the laser is reduced, and the image display effect of the laser projection equipment is ensured.
  • the embodiment of the present application provides a laser projection device.
  • each brightness sensor can detect the first brightness value of a laser, and the first brightness The value is sent to the display control circuit.
  • the display control circuit can obtain the second brightness value corresponding to the drive current of each group of lasers, and when it is detected that the difference between the second brightness value of the laser and the first brightness value of the laser within the target time period is greater than the difference threshold , It is determined that the laser has a COD failure. Then the display control circuit can adjust the current control signal of the corresponding laser driving component of the laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the laser.
  • the laser projection device provided in the embodiments of the present application can eliminate the COD failure of the laser in time, reduce the duration of the COD failure of the laser, reduce the damage rate of the laser, and ensure the image display effect of the laser projection device.
  • FIG. 11 shows a schematic diagram of a laser projection optical path structure.
  • the schematic diagram of the optical architecture of the laser projection device shown in FIG. 11 according to the optical function, it is divided into a light source 100, an optical engine 200 and a lens 300.
  • the light beam output by the light source 100 enters the optical engine 200, and the optical engine 200 then enters the light beam into the lens 300.
  • the light source 100 is a three-color laser light source capable of outputting red, green and blue lasers.
  • the light source 100 also includes a plurality of optical lenses, which combine and converge the laser beam.
  • the optical path of the light source output to the optical machine can also be provided with a speckle dissipating component, such as a moving diffuser, and a moving diffuser. After the diffuser diffuses the light beam, the divergence angle of the light beam can be increased, which is beneficial to improve the speckle phenomenon.
  • the moving diffuser can be set in the light source 100 or in the light engine 200. The light beam emitted from the light source 100 enters the optical engine 200.
  • light-receiving and homogenizing components such as a light pipe located at the front end of the light engine 200, are used to receive the illuminating beam of the light source and have the function of light mixing and homogenization.
  • the outlet of the light pipe is rectangular, which has a shaping effect on the light spot.
  • the optical machine 200 also includes a plurality of lens groups.
  • the TIR or RTIR prism is used to form an illumination light path, and the light beam is incident on the core key component-a light valve.
  • the light valve modulates the light beam and enters the lens group of the lens 300 for imaging.
  • the light valve can include many types, such as LCOS, LCD, or DMD.
  • the DLP architecture is applied, and the light valve is a DMD chip or a digital micro-mirror array.
  • the laser projection device mentioned in this example may be an ultra-short throw laser projection device.
  • the laser projection device in this example may adopt the laser projection optical path exemplified in the above multiple embodiments.
  • the laser light source 20 in the laser projection device may include a set of blue lasers 201, and the laser projection device may be referred to as a monochromatic laser projection device.
  • the at least one brightness sensor 40 may include a first brightness sensor 401, and the first brightness sensor 401 may be a blue light brightness sensor or a white light brightness sensor.
  • the first brightness sensor 401 is arranged on the light-emitting side of the blue laser 201.
  • the first brightness sensor is arranged on the light-emitting side of the blue laser 201, which improves the first brightness sensor 401 to detect the first brightness value of the laser. Accuracy.
  • the display control circuit 10 can read the value detected by the first brightness sensor 401 when the blue laser 201 outputs the target primary color light. Brightness value. And when outputting other primary color light than the target primary color light, stop reading the brightness value detected by the first brightness sensor 401.
  • the blue laser 201 has the largest driving current when outputting the target primary color light, and the target primary color light may be blue laser, red fluorescence or green fluorescence. In the process of projecting an image by the laser projection device, the first brightness sensor 401 is always in an on state.
  • the laser projection device may further include a first lens assembly 50, a first dichroic plate 601, a fluorescent wheel 70, a mirror assembly 80, a second lens assembly 90, a color filter wheel 100, and a receiver.
  • the optical component 110 a total internal reflection (TIR) lens 120, a digital micro mirror device (DMD) 130, and a projection lens 140.
  • the first brightness sensor 401 may be arranged between the light emitting side of the blue laser 201 and the first lens assembly 50.
  • the light receiving component 110 may also be referred to as a light rod.
  • the reflector assembly 80 may include a first reflector 801, a second reflector 802, and a third reflector 803.
  • the second lens assembly 90 may include a first lens 901, a second lens 902, and a third lens 903.
  • the blue laser light emitted by the blue laser 201 is condensed by the first lens assembly 50, passes through the transparent area of the first dichroic plate 601 and the fluorescent wheel 70, and sequentially passes through the first mirror 801 and the second mirror 802. And after the reflection of the third mirror 803. After passing through the first dichroic plate 601 again, and condensing light by the first lens 901, a blue laser light is generated through the transparent area of the filter color wheel 100.
  • the blue laser light emitted by the blue laser 201 is collected by the first lens assembly 50, passes through the first dichroic plate 601, and is projected to the yellow phosphor area of the phosphor wheel 70 to excite yellow fluorescence.
  • the yellow fluorescent light is reflected by the metal substrate of the fluorescent wheel 70, reflected again by the first dichroic plate 601, and the first lens 901 condenses light. Then, the yellow fluorescence is filtered by the filter color wheel 100 to generate red fluorescence.
  • the blue laser light emitted by the blue laser 201 is collected by the first lens assembly 50, passes through the first dichroic plate 601, and is projected to the green phosphor area of the phosphor wheel 70 to excite green fluorescence.
  • the green fluorescent light is reflected by the metal substrate of the fluorescent wheel 70, reflected again by the first dichroic plate 601, and the first lens 901 condenses light. After that, the green fluorescence is filtered by the filter color wheel 100 to generate green fluorescence.
  • the three primary colors of blue laser light, red fluorescent light and green fluorescent light generated by the filtered color wheel 100 are time-shared and homogenized by the light-receiving component 110, and after being shaped by the second lens 902 and the third lens 903, it enters the TIR lens 120. The reflection is reflected by the DMD 130 and then transmitted through the TIR lens 120, and finally projected onto the display screen through the projection lens 140 to form an image to be displayed.
  • the laser light source 20 in the laser projection device may include a set of blue lasers 201 and a set of red lasers 202.
  • the laser projection device It can be called a two-color laser projection device.
  • the at least one brightness sensor 40 may include a first brightness sensor 401 and a second brightness sensor 402.
  • the second brightness sensor 402 may be a red light brightness sensor and a white light brightness sensor.
  • the first brightness sensor 401 is arranged on the light output side of the blue laser 201
  • the second brightness sensor 402 is arranged on the light output side of the red laser 202.
  • the brightness sensor is arranged on the light output side of the laser, which improves the accuracy of the brightness sensor for detecting the first brightness value of the laser.
  • the display control circuit 10 is also used to read the brightness value detected by the first brightness sensor 401 when controlling the blue laser 201 to emit blue laser light. And when the blue laser 201 is controlled to be turned off, the reading of the brightness value detected by the first brightness sensor 401 is stopped.
  • the display control circuit 10 is also used to read the brightness value detected by the second brightness sensor 402 when controlling the red laser 202 to emit red laser light, and to stop reading the brightness detected by the second brightness sensor 402 when the red laser 202 is turned off. value.
  • the first brightness sensor 401 and the second brightness sensor 402 are always in an on state.
  • the laser projection device may further include a light receiving component 110.
  • the first brightness sensor 401 is disposed on the light-emitting side of the blue laser 201
  • the second brightness sensor 402 is disposed on the light-emitting side of the light receiving component 110.
  • the display control circuit 10 is also used to read the brightness value detected by the second brightness sensor 402 when the red laser 202 emits a red laser, and stop reading the brightness value detected by the second brightness sensor 402 when the red laser 202 is turned off , To ensure that the second brightness sensor 402 can detect the first brightness value of the red laser 202.
  • the display control circuit 10 is further configured to read the brightness value detected by the first brightness sensor 401 when controlling the blue laser 201 to emit blue laser light. And when the blue laser 201 is controlled to be turned off, the reading of the brightness value detected by the first brightness sensor 401 is stopped.
  • the laser projection device may further include a first lens assembly 50, a second dichroic plate 602, a third dichroic plate 603, a fluorescent wheel 70, a mirror assembly 80, and a second lens assembly.
  • the first lens assembly 50 may include a fourth lens 501 and a fifth lens 502.
  • the mirror assembly 80 may include a first mirror 801, a second mirror 802, and a fourth mirror 804.
  • the second lens assembly 90 may include a first lens 901, a second lens 902, and a third lens 903.
  • the blue laser light emitted by the blue laser 201 is collected by the fourth lens 501, passes through the second dichroic plate 602, passes through the transparent area of the fluorescent wheel 70, and passes through the first reflector.
  • the continuous reflection of 801 and the second mirror 802 is again reflected by the third dichroic plate 603, passes through the second dichroic plate 602, and collects light by the first lens 901, and then passes through the transparent area of the filter color wheel 100 After entering the light receiving part 110 to homogenize the light, a blue laser light is generated.
  • the blue laser light emitted by the blue laser 201 is condensed by the fourth lens 501, passes through the second dichroic plate 602, and is projected to the yellow phosphor area on the phosphor wheel 70 to excite yellow fluorescence.
  • the metal substrate of the fluorescent wheel 70 is reflected again by the second dichroic plate 602, and after the light is collected by the first lens 901, the color is filtered by the color filter wheel 100 and enters the light-receiving part 110 to generate yellow fluorescence.
  • the blue laser light emitted by the blue laser 201 is condensed by the fourth lens 501, passes through the second dichroic plate 602, and is projected to the green phosphor area on the phosphor wheel 70 to excite green fluorescence.
  • the metal substrate of the fluorescent wheel 70 is reflected again by the second dichroic plate 602, and after the light is collected by the first lens 901, the color is filtered by the filter color wheel 100 and enters the light receiving part 110 to generate green fluorescence.
  • the red laser light emitted by the red laser 202 is collected by the fifth lens 502, it is reflected by the fourth mirror 804, passes through the third dichroic plate 603 and the second dichroic plate 602, directly enters the first lens 901, and passes through The transparent area of the filter color wheel 100 enters the light receiving part 110 to homogenize the light to obtain the red laser light.
  • the four primary colors of red laser, blue laser, green fluorescence and yellow fluorescence time-sharing pass through the light-receiving part 110 to homogenize the light, then pass through the second lens 902 and the third lens 903 after shaping, enter the TIR lens 120 for total reflection, and pass through the DMD After reflection 130, it passes through the TIR lens 120, and finally is projected onto the display screen through the projection lens 140 to form an image to be displayed.
  • the laser light source 20 in the laser projection device may include a group of blue lasers 201, a group of red lasers 202, and a group of green lasers that are independently arranged.
  • the laser 203, the laser projection equipment is provided with a laser that can emit light of three primary colors, so that there is no need to install a fluorescence conversion device such as a fluorescent wheel.
  • a fluorescence conversion device can also be provided in addition to the three-color laser to generate partial metamerism with the laser type to supplement the laser light of the same color.
  • the blue laser 201, the red laser 202, and the green laser 203 in this example are all MCL (multi-chip laser-diode, multi-chip laser light-emitting diode) type packaged lasers, which are small in size and facilitate the compact arrangement of the optical path.
  • MCL multi-chip laser-diode, multi-chip laser light-emitting diode
  • the at least one brightness sensor 40 may include a first brightness sensor 401, a second brightness sensor 402, and a third brightness sensor 403.
  • the third brightness sensor 403 is a green light brightness sensor. Or white light brightness sensor.
  • the first brightness sensor 401 is arranged on the light output side of the blue laser 201
  • the second brightness sensor 402 is arranged on the light output side of the red laser 202
  • the third brightness sensor 403 is arranged on the light output side of the green laser 203. Since the laser light emitted by the laser is not attenuated on the light output side, the brightness sensor is arranged on the light output side of the laser, which improves the accuracy of the brightness sensor for detecting the first brightness value of the laser.
  • the display control circuit 10 is also used to read the brightness value detected by the first brightness sensor 401 when controlling the blue laser 201 to emit blue laser light. And when the blue laser 201 is controlled to be turned off, the reading of the brightness value detected by the first brightness sensor 401 is stopped.
  • the display control circuit 10 is also used to read the brightness value detected by the second brightness sensor 402 when controlling the red laser 202 to emit red laser light, and to stop reading the brightness value detected by the second brightness sensor 402 when the red laser 202 is turned off. Brightness value.
  • the display control circuit 10 is also used to read the brightness value detected by the third brightness sensor 403 when the green laser 203 is controlled to emit green laser light, and to stop reading the third brightness sensor 403 when the green laser 203 is turned off. The brightness value.
  • the laser projection device may further include a light receiving component 110.
  • the at least one brightness sensor 40 may include a fourth brightness sensor 404, and the fourth brightness sensor 404 may be white light brightness. sensor.
  • the fourth brightness sensor 404 is arranged on the light emitting side of the light receiving component 110.
  • the display control circuit 10 is also used to read the brightness value detected by the fourth brightness sensor 404 when the blue laser 201, the red laser 202, and the green laser 203 are turned on in a time-division manner, so as to ensure that the fourth brightness sensor 404 can detect To the first brightness value of the blue laser 201, the first brightness value of the red laser 202, and the first brightness value of the green laser 203. And when the blue laser 201, the red laser 202 and the green laser 203 are all turned off, the reading of the brightness value detected by the fourth brightness sensor 404 is stopped.
  • the fourth brightness sensor 404 is always in an on state.
  • the laser projection device may further include a fourth dichroic plate 604, a fifth dichroic plate 605, a fifth mirror 904, a second lens assembly 90, a diffusion wheel 150, and TIR Lens 120, DMD 130 and projection lens 140.
  • the second lens assembly 90 includes a first lens 901, a second lens 902, and a third lens 903.
  • the fourth dichroic film 604 can transmit blue laser light and reflect green laser light.
  • the fifth dichroic sheet 605 can transmit red laser light and reflect green laser light and blue laser light.
  • the blue laser light emitted by the blue laser 201 passes through the fourth dichroic plate 604, and then is reflected by the fifth dichroic plate 605 and enters the first lens 901 to collect light.
  • the red laser light emitted by the red laser 202 passes through the fifth dichroic plate 605 and directly enters the first lens 901 to collect light.
  • the green laser light emitted by the green laser 203 is reflected by the fifth reflecting mirror 904, is reflected by the fourth dichroic plate 604 and the fifth dichroic plate 605 in turn, and then enters the first lens 901 to collect light.
  • the blue laser, red laser and green laser light collected by the first lens 901 pass through the rotating diffuser wheel 150 to dissipate the speckle in a time-sharing manner, and are projected to the light receiving part 110 after homogenization, and then pass through the second lens 902 and the third lens 902 and the third lens 902.
  • the lens 903 is reshaped and enters the TIR lens 120 for total reflection, is reflected by the DMD 130, and then passes through the TIR lens 120, and finally is projected onto the display screen through the projection lens 140 to form an image to be displayed.
  • the laser light source 20 in the laser projection device may be an MCL type laser, for example, an MCL type laser, where the one MCL type laser is shown in FIG.
  • a substrate 2001 is included.
  • the substrate 2001 and the surrounding frame form a concave space.
  • a plurality of light-emitting chips are attached to the inner and upper surface of the substrate 2001, and the plurality of light-emitting chips can emit red, blue, and green lasers.
  • Lead terminals are led out from the side of the frame for powering on to drive the light-emitting chip of the laser, and a collimating lens group 2003 is also covered above the light-emitting surface of the light-emitting chip, with multiple collimating lenses corresponding to the light-emitting chip's Light beam.
  • a three-color laser can be emitted through an MCL laser.
  • the MCL laser includes light-emitting chips arranged in rows and columns, and may include two rows of red lasers 202, one row of blue lasers 201, and one row of green lasers 203.
  • This laser projection device can be called a full-color laser projection device.
  • the blue laser 203 in the laser projection device is arranged in the middle of the red laser 202 and the green laser 203. Since the blue laser 201 can withstand a higher temperature, the blue laser 203 is placed in the middle of the red laser 202 and the green laser 203. This setting is more conducive to the rapid heat dissipation of the red laser 202 and the green laser 203, so that The reliability of the integrated multiple lasers is higher.
  • the brightness sensor 40 may include a first brightness sensor 401, a second brightness sensor 402, and a third brightness sensor 403.
  • the first brightness sensor 401 is arranged in the light exit path of the blue laser 201, specifically, the side of the collimated beam exit path of the blue laser beam is arranged without blocking the light path.
  • the second brightness sensor 402 The third brightness sensor 403 is arranged in the light output path of the collimated beam of the two rows of red lasers 202, specifically, on the side of the light output path of the red laser beam.
  • the third brightness sensor 403 is arranged in the light output path of the green laser 203.
  • the collimated beam of the laser beam is one side of the light path.
  • the display control circuit 10 is also used to read the brightness value detected by the first brightness sensor 401 when controlling the blue laser 201 to emit blue laser light. And when the blue laser 201 is controlled to be turned off, the reading of the brightness value detected by the first brightness sensor 401 is stopped.
  • the display control circuit 10 is also used to read the brightness value detected by the second brightness sensor 402 when controlling the red laser 202 to emit red laser light, and to stop reading the brightness value detected by the second brightness sensor 402 when the red laser 202 is turned off. Brightness value.
  • the display control circuit 10 is also used to read the brightness value detected by the third brightness sensor 403 when the green laser 203 is controlled to emit green laser light, and to stop reading the third brightness sensor 403 when the green laser 203 is turned off. The brightness value.
  • the first brightness sensor 401 may be a blue first brightness sensor or a white brightness sensor
  • the second brightness sensor 402 is a red brightness sensor or a white brightness sensor
  • the third brightness sensor 403 is a green brightness sensor or a white brightness sensor.
  • the laser projection device may further include a light-receiving component 110, specifically, the light-receiving component 110 may be a light pipe.
  • the brightness sensor 40 may include a fourth brightness sensor 404.
  • the fourth brightness sensor 404 is arranged in the light output path of the two red lasers 202, the light output path of the blue laser 201 and the light output path of the green laser 203. That is, the fourth brightness sensor 404 is arranged in the light exit path of the laser light source 20. Or, referring to FIG. 4, the fourth brightness sensor 404 is arranged in the light exit path of the light pipe 110.
  • the display control circuit 10 is also used for reading the brightness value detected by the fourth brightness sensor 404 when the laser projection device is controlled to start projecting a display image.
  • the fourth brightness sensor 404 is used to detect the first brightness value of the blue laser 201 when the blue laser 201 emits blue laser light.
  • the red laser 202 emits a red laser
  • the first brightness value of the red laser 202 is detected.
  • the green laser 203 emits a green laser
  • the first brightness value of the green laser 203 is detected.
  • the laser projection device is controlled to stop projecting and displaying an image, it stops reading the brightness value detected by the fourth brightness sensor 404.
  • the laser projection device may further include four fifth reflecting glasses 805, a second lens assembly 90, a TIR lens 120, a DMD 130, a projection lens 140, and a diffusion wheel 150.
  • the second lens assembly 90 includes a first lens 901, a second lens 902, and a third lens 903.
  • Each laser is provided with a fifth reflecting mirror 805 correspondingly.
  • the blue laser light emitted by the blue laser 201 is reflected by the fifth reflector 805 at the corresponding position, collected by the first lens 901, uniformed by the diffuser wheel 150, and then uniformly reflected by the light pipe 110.
  • the red laser light emitted by the red laser 202 is reflected by the fifth reflector 805 at the corresponding position and collected by the first lens 901.
  • the red laser light is defocused and chromatic uniformed through the diffuser wheel 150, and then passes through the light pipe 110 Perform total reflection and homogenization.
  • the green laser light emitted by the green laser 202 is reflected by the fifth reflector 805 at the corresponding position and collected by the first lens 901.
  • the green laser light is defocused and chromatic uniformed through the diffuser wheel 150, and then passes through the light pipe 110 Perform total reflection and homogenization.
  • the blue laser, red laser and green laser that have been homogenized through the light pipe 110 are time-sharing shaped by the second lens 902 and the third lens 903, and enter the TIR lens 120 for total reflection, and then pass through the TIR lens 120 after being reflected by the DMD 130 , And finally projected onto the display screen through the projection lens 140 to form the image to be displayed.
  • the laser driving component 30 may include a driving circuit 301, a switching circuit 302, and an amplifying circuit 303.
  • the driving circuit 301 may be a driving chip.
  • the switch circuit 302 may be a metal-oxide-semiconductor (MOS) tube.
  • the driving circuit 301 is respectively connected to the corresponding laser included in the switch circuit 302, the amplifying circuit 303, and the laser light source 20.
  • the driving circuit 301 is configured to output a driving current to the corresponding laser in the laser light source 20 through the VOUT terminal based on the current control signal sent by the display control circuit 10, and transmit the received enable signal to the switch circuit 302 through the ENOUT terminal.
  • the laser may include n sub-lasers connected in series, namely sub-lasers LD1 to LDn. n is a positive integer greater than zero.
  • the switch circuit 302 is connected in series in the current path of the laser, and is used to control the conduction of the current path when the received enable signal is at an effective potential.
  • the amplifying circuit 303 is respectively connected to the detection node E in the current path of the laser light source 20 and the display control circuit 10, for converting the detected driving current of the laser assembly 201 into a driving voltage, amplifying the driving voltage, and converting the amplified The driving voltage is transmitted to the display control circuit 10.
  • the display control circuit 10 is also used to determine the amplified driving voltage as the driving current of the laser, and obtain the second brightness value corresponding to the driving current.
  • the amplifying circuit 303 may include: a first operational amplifier A1, a first resistor (also called a sampling power resistor) R1, a second resistor R2, a third resistor R3, and a fourth resistor R4.
  • the non-inverting input terminal (also called the positive terminal) of the first operational amplifier A1 is connected to one end of the second resistor R2, and the inverting input terminal (also called the negative terminal) of the first operational amplifier A1 is connected to one end and the first terminal of the third resistor R3 respectively.
  • One end of the four resistors R4 is connected, and the output end of the first operational amplifier A1 is respectively connected to the other end of the fourth resistor R4 and the processing sub-circuit 3022.
  • One end of the first resistor R1 is connected to the detection node E, and the other end of the first resistor R1 is connected to the reference power terminal.
  • the other end of the second resistor R2 is connected to the detection node E, and the other end of the third resistor R3 is connected to the reference power terminal.
  • the reference power terminal is the ground terminal.
  • the first operational amplifier A1 may also include two power terminals, one of which is connected to the power terminal VCC, and the other power terminal may be connected to the reference power terminal.
  • the larger drive current of the laser 20 includes a laser light source through a first resistor R1 is a voltage drop, the voltage V i to the end of the first resistor R1 (i.e., the detection node E) is transmitted to the second resistor R2 through a first operational amplifier
  • the non-inverting input terminal of A1 is output after being amplified by N times by the first operational amplifier A1.
  • the N is the amplification factor of the first operational amplifier A1, and N is a positive number.
  • the amplification factor N can make the value of the voltage V fb output by the first operational amplifier A1 an integer multiple of the value of the driving current of the laser.
  • the value of the voltage V fb may be equal to the value of the driving current, so that the display control circuit 10 can determine the amplified driving voltage as the driving current of the laser.
  • the input and output voltage amplification formula of the first operational amplifier A1 is: V i is the input voltage of the first operational amplifier A1, and V fb is the output voltage of the first operational amplifier A1.
  • the amplification factor N of the first operational amplifier A1 satisfies:
  • the display control circuit 10, the driving circuit 301, the switch circuit 302, and the amplifying circuit 303 form a closed loop to realize feedback adjustment of the driving current of the laser, so that the display control circuit 10 can pass the laser
  • the difference between the second brightness value and the first brightness value is to adjust the driving current of the laser in time, that is, to adjust the actual luminous brightness of the laser in time to avoid long-term COD failure of the laser and improve the accuracy of laser emission control.
  • the laser light source 20 includes a group of blue lasers 201, a group of red lasers 202 and a group of green lasers 203.
  • the blue laser 201 may be set at the L1 position
  • the red laser 202 may be set at the L2 position
  • the green laser 203 may be set at the L3 position.
  • the laser at the position L1 passes through the fourth dichroic plate 604 once, and then passes through the fifth dichroic plate 605 to reflect once and enters the first lens 901.
  • Pt represents the transmittance of the dichroic film
  • Pf represents the reflectance of the dichroic film or the fifth reflectance 904.
  • Table 1 shows the transmittance Pt of each laser through each dichroic plate and the reflectivity of each dichroic plate or the fifth mirror 904 reflected.
  • the transmittance of red laser light through each dichroic plate is 97%
  • the reflectance of red laser light reflected by each dichroic plate or fifth mirror 904 is 99%.
  • the maximum light efficiency at the L1 position is 96.03%.
  • the light efficiency of the blue laser is 96.5%
  • the light efficiency of the red laser is 97%
  • the light efficiency of the green laser is 96.5%, that is, the light efficiency of the red laser is the highest at the L1 position.
  • the maximum light efficiency at the L1 position is 97%.
  • the laser at the position L3 is reflected once by the fifth mirror 904, once by the fourth dichroic plate 604, and once again by the fifth dichroic plate 605 before entering the first lens 901.
  • the laser at the L3 position is reflected three times in total.
  • the optical efficiency of the laser at the L3 position is the highest, and the optical efficiency of the laser at the L1 position is the lowest.
  • the green laser 203 is set at the L3 position, the red laser 202 is set at the L2 position, and the blue laser 201 is set at the L1 position. That is, the green laser 203 is arranged in the optical path with the highest light efficiency, so as to ensure that the laser projection device can obtain the highest light efficiency.
  • the laser light source of the laser projection device is a monochromatic laser light source
  • the blue brightness sensor located on the light output side of the blue laser can detect the first brightness value Send to the display control circuit.
  • the display control circuit can obtain the second brightness value corresponding to the driving current of the blue laser.
  • the display control circuit can Reduce the duty cycle of the current control signal of the laser drive component corresponding to the blue laser to reduce the drive current of the blue laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD of the blue laser Failure, restore the normal operation of the blue laser.
  • the laser light source of the laser projection device is a blue-red two-color laser light source
  • the blue brightness sensor located on the light-emitting side of the blue laser can send the detected first brightness value to the display control circuit .
  • the display control circuit can obtain the second brightness value corresponding to the driving current of the blue laser.
  • the display control circuit 10 When the difference between the second brightness value and the first brightness value is greater than the difference threshold within the target duration, it is determined that the brightness of the blue laser drops sharply, that is, the blue laser has a COD failure, then the display control circuit 10 The duty cycle of the current control signal of the laser drive component corresponding to the blue laser can be reduced to reduce the drive current of the laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the blue laser , To resume the normal operation of the blue laser.
  • the red light brightness sensor located on the light output side of the red laser or the white light brightness sensor located on the light output side of the light receiving part can send the detected first brightness value to the display control circuit.
  • the display control circuit can obtain the second brightness value corresponding to the driving current of the red laser.
  • the display control circuit 10 can The duty cycle of the current control signal of the laser driving component corresponding to the red laser is reduced to reduce the driving current of the red laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the red laser and restoring the red color The normal operation of the laser.
  • the laser light source of the laser projection equipment is a three-color laser light source
  • the blue light brightness sensor located on the light output side of the blue laser or the white light brightness sensor located on the light output side of the light receiving part can detect The first brightness value of is sent to the display control circuit.
  • the display control circuit can obtain the second brightness value corresponding to the driving current of the blue laser.
  • the display control circuit 10 When the difference between the second brightness value and the first brightness value is greater than the difference threshold within the target duration, it is determined that the brightness of the blue laser drops sharply, that is, the blue laser has a COD failure, then the display control circuit 10 The duty cycle of the current control signal of the laser drive component corresponding to the blue laser can be reduced to reduce the drive current of the blue laser until the difference is less than or equal to the difference threshold, thereby eliminating the blue laser COD failure, restore the normal operation of the blue laser.
  • the red light brightness sensor located on the light output side of the red laser or the white light brightness sensor located on the light output side of the light receiving component can send the detected first brightness value to the display control circuit.
  • the display control circuit can obtain the second brightness value corresponding to the driving current of the red laser.
  • the display control circuit 10 can The duty cycle of the current control signal of the laser driving component corresponding to the red laser is reduced to reduce the driving current of the red laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the red laser and restoring the red color The normal operation of the laser.
  • the green light brightness sensor located on the light output side of the green laser or the white light brightness sensor located on the light output side of the light receiving part can send the detected first brightness value to the display control circuit.
  • the display control circuit can obtain the second brightness value corresponding to the driving current of the green laser. And when the difference between the second brightness value and the first brightness value is greater than the difference threshold within the target time period, it can be determined that the brightness of the green laser drops sharply, that is, the green laser has a COD failure, and the display control circuit can Reduce the duty cycle of the current control signal of the laser drive component corresponding to the green laser to reduce the drive current of the green laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the green laser. Restore the normal operation of the green laser.
  • the laser projection device provided in the present application can apply the laser light sources in the above-mentioned multiple examples.
  • laser failures can be found in time, and the drive current can be reduced to interfere in time to prevent the laser from being in a COD failure state for a long time, and to promote the repair of laser failures.
  • the normal PWM signal output can be performed after the fault is eliminated, the laser is normally driven, and the closed-loop self-recovery control is performed, which improves the reliability and stability of the laser light source and ensures the quality of the projection image.

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Abstract

一种激光投影设备，包括显示控制电路（10）、激光光源（20）、激光器驱动组件（30）和亮度传感器（40）。显示控制电路（10）用于驱动激光光源（20）发光，亮度传感器（40）用于检测激光器（20）的第一亮度值，并将第一亮度值发送至显示控制电路（10），显示控制电路（10）用于获取激光器（20）的驱动电流对应的第二亮度值，根据第二亮度值和第一亮度值的差值，调整激光器驱动组件（30）的电流控制信号，直至第一亮度和第一亮度的差值满足阈值要求。

Description

激光投影设备
相关申请的交叉引用
本申请要求在2020年3月9日提交中国专利局、申请号为202010157119.5，发明名称为“激光投影设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及投影显示领域，特别涉及一种激光投影设备。
背景技术
目前，激光投影设备可以包括激光光源，该激光光源可以包括至少一种颜色的激光器。例如，若该激光投影设备为单色激光投影设备，则该激光光源可以包括用于出射蓝色激光的蓝色激光器。若该激光投影设备为全色激光投影设备，则该激光光源可以包括蓝色激光器、用于出射红色激光的红色激光器和用于出射绿色激光的绿色激光器。
相关技术中，激光投影设备中的激光器在出射激光的过程中，会由于激光器半导体结超过功率密度导致过载，而使激光器的腔面需承受较大的光功率密度而熔化以及再结晶，使激光器的腔面会吸收较多光产生的热量从而产生较大的温升，进而使得激光器的腔面发生灾变性光学镜面损伤(catastrophic optical damage，COD)，而激光器发生上述故障时，但其电流和电压基本保持不变，因此，即便是通过监控电流和电压变化难以检测到上述故障。如果激光器长时间发生COD故障，最终会导致激光器永久性损伤，也使得激光投影设备的投影画面质量急剧恶化。这也降低了激光器和激光投影设备使用寿命和工作可靠性。
发明内容
本申请实施例提供了一种激光投影设备，包括：显示控制电路、激光光源、至少一个激光器驱动组件以及至少一个亮度传感器；
激光光源包括与至少一个激光器驱动组件一一对应的至少一组激光器；
显示控制电路用于向至少一个激光器驱动组件输出基色使能信号以及基色电流控制信号，以驱动至少一组激光器发光，亮度传感器设置于激光光源的出光路径中，用于检测至少一组激光器的第一亮度值，并将第一亮度值发送至显示控制电路；
显示控制电路，还用于获取每个激光器的驱动电流对应的第二亮度值，若激光器的第二亮度值与激光器的第一亮度值的差值大于差值阈值，调整与激光器对应的激光器驱动组件的 电流控制信号，直至差值小于等于差值阈值。
附图说明
为了更清楚地说明本申请实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是相关技术所提供的一种激光器发生COD故障时激光器的输出特性的示意图；
图2A是本申请实施例提供的一种激光投影设备的电路原理示意图；
图2B是本申请实施例提供的又一种激光投影设备的电路原理示意图；
图3是本申请实施例提供的另一种激光投影设备的结构示意图；
图4是本申请实施例提供的又一种激光投影设备的结构示意图；
图5是本申请实施例提供的再一种激光投影设备的结构示意图；
图6是本申请实施例提供的又一种激光投影设备的结构示意图；
图7是本申请实施例提供的又一种激光投影设备的结构示意图；
图8是本申请实施例提供的又一种激光投影设备的结构示意图；
图9是本申请实施例提供的另一种激光投影设备的结构示意图；
图10是本申请实施例提供的又一种激光投影设备的电路原理示意图；
图11为本申请实施例提供的一种激光投影设备的光路架构原理示意图；
图12为本申请实施例提供的一种激光器的外观结构示意图。
具体实施方式
为使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请实施方式作进一步地详细描述。
图1是相关技术所提供的一种激光器发生COD故障时激光器的输出特性的示意图。该示意图包括第一曲线和第二曲线，第一曲线为激光器的驱动电压的变化曲线，第二曲线为激光器的驱动电流的变化曲线。该示意图中的横坐标为驱动电流，第一纵坐标为激光器的发光功率，第二纵坐标为激光器的驱动电压。其中，驱动电流的单位为安(A)，发光功率的单位为毫瓦(mW)，驱动电压的单位为伏特(V)。
参考图1，激光器在工作的过程中，随着激光器接收到的驱动电流的增大，当该驱动电流增大至远超过激光器的额定电流时，激光器发生COD故障。在激光器发生COD故障时，其驱动电流和驱动电压基本保持不变，但激光器的发光功率会骤然降低。其中，虽然 驱动激光器发光的电功率不变，但激光器发出的光主要被激光器内部的腔面吸收转化成热量，使得激光器的腔面产生较大的温升，从而损伤激光器的腔面。由于只有小部分激光从激光器内部发射出来，因此激光器的发光功率会骤然降低(即激光器的发光亮度会降低)。也即是激光器在发生COD故障时，其将在较高的驱动电流下工作，但却无法提供与该驱动电流相匹配的发光亮度。长此以往，会导致激光器出现损伤，激光投影设备的图像显示效果较差。
本申请实施例提供的激光投影设备，通过在激光光源的出光侧设置至少一个亮度传感器，该每个亮度传感器可以检测一组激光器的第一亮度值。该显示控制电路可以获取每组激光器的驱动电流对应的第二亮度值，并在确定该激光器的第二亮度值与该激光器的第一亮度值的差值大于差值阈值时，确定该激光器发生COD故障。则显示控制电路可以调整该激光器对应的激光器驱动组件的电流控制信号，直至该差值小于等于该差值阈值，从而消除该激光器的COD故障。相较于相关技术，该激光投影设备能够及时消除激光器的COD故障，减少激光器发生COD故障的持续时长，降低了激光器的损坏率，确保了激光投影设备的图像显示效果。
图2A是本申请实施例提供的一种激光投影设备的原理示意图。如图2A所示，该激光投影设备可以包括显示控制电路10、激光光源20、激光器驱动组件30以及亮度传感器40。激光光源20可以包括与激光器驱动组件30对应的至少一组激光器200。其中，该至少一个是指一个或多个，多个是指两个或两个以上。该至少一组是指一组或多组，多组是指两组或两组以上，每组激光器可以包括一个或多个激光器。
如图2B所示，该激光投影设备可以包括显示控制电路10、激光光源20、至少一个激光器驱动组件30以及至少一个亮度传感器40，该激光光源20可以包括与至少一个激光器驱动组件30一一对应的至少一组激光器。其中，该至少一个是指一个或多个，多个是指两个或两个以上。该至少一组是指一组或多组，多组是指两组或两组以上，每组激光器可以包括一个或多个激光器。
图2B所示的激光投影设备包括三个激光器驱动组件30和一个亮度传感器40，相应的，该激光光源20包括与该三个激光器驱动组件30一一对应的三组激光器，该三组激光器可以分别为蓝色激光器201、红色激光器202和绿色激光器203。其中，该蓝色激光器201用于出射蓝色激光，该红色激光器202用于出射红色激光，该绿色激光器203用于出射绿色激光。
显示控制电路10与每个激光器驱动组件30连接，用于输出与多帧显示图像中的每一帧图像的三种基色一一对应的至少一个使能信号，将至少一个使能信号分别传输至对应的 激光器驱动组件30，以及，输出与每一帧图像的三种基色一一对应的至少一个电流控制信号，将至少一个电流控制信号分别传输至对应的激光器驱动组件30。示例的，该显示控制电路10可以为微控制单元(microcontroller unit，MCU)，又称为单片机。其中，该电流控制信号可以是脉冲宽度调制(pulse width modulation，PWM)信号。
示例的，参考图2B，该显示控制电路10可以基于待显示图像的蓝色基色分量输出与蓝色激光器201对应的蓝色PWM信号B_PWM，基于待显示图像的红色基色分量输出与红色激光器202对应的红色PWM信号R_PWM，基于待显示图像的绿色基色分量输出与绿色激光器203对应的绿色PWM信号G_PWM。该显示控制电路01可以基于蓝色激光器201在驱动周期内的点亮时长，输出与蓝色激光器201对应的使能信号B_EN，基于红色激光器202在驱动周期内的点亮时长，输出与红色激光器202对应的使能信号R_EN，基于绿色激光器203在驱动周期内的点亮时长，输出与绿色激光器203对应的使能信号G_EN。
每个激光器驱动组件30与对应的一组激光器连接，用于响应于接收到的使能信号和电流控制信号，向其所连接的激光器提供对应的驱动电流。
每组激光器用于在对应的激光器驱动组件30提供的驱动电流的驱动下发光。
示例的，参考图2B，该蓝色激光器201、红色激光器202和绿色激光器203分别与对应的激光器驱动组件30连接。该蓝色激光器201对应的激光器驱动组件30可以响应于显示控制电路10发送的蓝色PWM信号B_PWM和使能信号B_EN，向该蓝色激光器201提供对应的驱动电流。该蓝色激光器201用于在该驱动电流的驱动下发光。
至少一个亮度传感器40设置在激光光源20的出光侧，该每个亮度传感器与显示控制电路10连接，用于检测一组激光器的第一亮度值，并将第一亮度值发送至显示控制电路10。
显示控制电路10，还用于获取每组激光器的驱动电流对应的第二亮度值，当检测到在目标时长内该激光器的第二亮度值与该激光器的第一亮度值的差值大于差值阈值，表明该激光器的亮度骤降，即该激光器发生COD故障，显示控制电路10可以调整与激光器对应的激光器驱动组件30的电流控制信号，直至该差值小于等于该差值阈值，即通过降低激光器的驱动电流来消除该激光器的COD故障。若检测到的该激光器的第二亮度值与该激光器的第一亮度值的差值小于等于差值阈值，表明该激光器未发生COD故障，则显示控制电路10无需调整与该激光器对应的激光器驱动组件30的电流控制信号。该目标时长可以为显示控制电路10中预先存储的固定时长。
其中，显示控制电路10中可以存储有电流与亮度值之间的对应关系。该对应关系中每个电流对应的亮度值为激光器在该电流的驱动下正常工作(即在未发生COD故障)时， 该激光器能够发出的初始亮度值。例如，该亮度值可以是激光器在该电流的驱动下工作时，其首次点亮时的初始亮度。
显示控制电路10可以从该对应关系中获取每组激光器的驱动电流对应的第二亮度值，该驱动电流为激光器当前的实际工作电流，该驱动电流对应的第二亮度值为激光器在该驱动电流的驱动下正常工作时能够发出的亮度值。该差值阈值可以为显示控制电路10中预先存储的固定数值。
可选的，显示控制电路10当检测到在目标时长内激光器的第二亮度值与激光器的第一亮度值的差值大于差值阈值时，可以降低与激光器对应的激光器驱动组件30的电流控制信号的占空比，从而降低激光器的驱动电流。以及，该显示控制电路10用于当检测到激光器的第二亮度值与该激光器的第一亮度值的差值小于或等于差值阈值时，保持与激光器对应的激光器驱动组件的电流控制信号的占空比不变，即显示控制电路10向与激光器对应的激光器驱动组件提供降低后的电流控制信号，并保持该降低后的电流控制信号的占空比不变，相应的，该激光器驱动组件30向对应的激光器提供降低后的驱动电流，该激光器在该降低后的驱动电流的驱动下发光，从而形成一个闭环自动调整的过程。
示例的，若该至少一个亮度传感器40包括一个亮度传感器40，参考图2B，该亮度传感器40可以检测蓝色激光器201的第一亮度值，并将该第一亮度值发送至显示控制电路10。该显示控制电路10可以获取该蓝色激光器201的驱动电流，并从电流与亮度值的对应关系中获取该驱动电流对应的第二亮度值。之后检测在目标时长内该第二亮度值与第一亮度值之间的差值是否大于差值阈值，若该差值大于差值阈值，表明该蓝色激光器201发生COD故障，则显示控制电路10可以降低与该蓝色激光器201对应的激光器驱动组件30的电流控制信号的占空比。之后显示控制电路10可以再次获取蓝色激光器201的第一亮度值，以及蓝色激光器201的驱动电流对应的第二亮度值，并在第二亮度值与第一亮度值之间的差值大于差值阈值时，再次降低与该蓝色激光器201对应的激光器驱动组件30的电流控制信号的占空比。如此循环，当检测到激光器的第二亮度值与该激光器的第一亮度值的差值小于或等于差值阈值时，保持该与激光器对应的激光器驱动组件的电流控制信号的占空比不变。由此通过降低蓝色激光器201的驱动电流，消除该蓝色激光器201的COD故障。
在本申请实施例中，显示控制电路10可以根据至少一个亮度传感器40获取到的每一组激光器的第一亮度值，以及每组激光器的驱动电流对应的第二亮度值，实时监测每组激光器是否发生COD故障。并在确定任一组激光器发生COD故障时，及时消除该激光器的COD故障，减少激光器发生COD故障的持续时长，降低该激光器的损伤，确保激光投影 设备的图像显示效果。
综上所述，本申请实施例提供了一种激光投影设备，通过在激光光源的出光侧设置至少一个亮度传感器，该每个亮度传感器可以检测一个激光器的第一亮度值，并将第一亮度值发送至显示控制电路。该显示控制电路可以获取每组激光器的驱动电流对应的第二亮度值，并当检测到在目标时长内该激光器的第二亮度值与该激光器的第一亮度值的差值大于差值阈值时，确定该激光器发生COD故障。则显示控制电路可以调整激光器的对应的激光器驱动组件的电流控制信号，直至该差值小于等于该差值阈值，从而消除该激光器的COD故障。相较于相关技术，本申请实施例提供的激光投影设备能够及时消除激光器的COD故障，减少激光器发生COD故障的持续时长，降低了激光器的损坏率，确保了激光投影设备的图像显示效果。
以及，图11示出了一种激光投影光路架构示意图。如图11所示的激光投影设备光学架构示意图中，按照光学功能划分，分为光源100，光机200和镜头300。光源100输出的光束入射至光机200中，光机200再将光束入射至镜头300。其中光源100为三色激光光源，能够输出红绿蓝三色激光。光源100还包括多个光学镜片，对激光光束合光和会聚。由于激光本身具有较强的相干性，因此，为了改善激光投影带来的散斑问题，在光源输出至光机的光路中还可设置有消散斑部件，比如，运动的扩散片，经运动的扩散片对光束进行扩散后，可增加光束的发散角度，利于改善散斑现象。运动的扩散片可设置于光源100中，也可以设置于光机200中。从光源100出射的光束入射至光机200。通常收光、匀化部件，比如光导管位于光机200的前端，用于接收光源的照明光束，具有混光和匀化的作用，且光导管的出口为矩形，对光斑具有整形效果。光机200中还包括多个透镜组，TIR或RTIR棱镜用于形成照明光路，将光束入射至核心关键器件-光阀，光阀调制光束后入射至镜头300的透镜组中进行成像。根据投影架构的不同，光阀可以包括很多种，比如LCOS，LCD或者DMD，在本示例中，应用DLP架构，光阀为DMD芯片或称数字微镜阵列。
本示例中提到的激光投影设备可以为超短焦激光投影设备。
本示例中的激光投影设备可以采用上述多个实施例中所示例的激光投影光路。
在一种可选的实现方式中，如图3所示，该激光投影设备中的激光光源20可以包括一组蓝色激光器201，该激光投影设可以称为单色激光投影设备。该至少一个亮度传感器40可以包括第一亮度传感器401，该第一亮度传感器401可以为蓝光亮度传感器或者白光亮度传感器。该第一亮度传感器401设置在蓝色激光器201的出光侧。
由于该蓝色激光器201出射的蓝色激光在其出光侧并未出现衰减，将第一亮度传感器设置在蓝色激光器201的出光侧，提高了第一亮度传感器401对激光器的第一亮度值检测 的精度。
可选的，由于蓝色激光器201在输出不同种基色光时驱动电流的大小可能不同，因此该显示控制电路10可以在蓝色激光器201输出目标基色光时，读取第一亮度传感器401检测的亮度值。并在输出除目标基色光以外的其他基色光时，停止读取第一亮度传感器401检测的亮度值。其中，该蓝色激光器201输出目标基色光时的驱动电流最大，该目标基色光可以为蓝色激光、红色荧光或者绿色荧光。在激光投影设备投影图像的过程中，该第一亮度传感器401一直处于开启状态。
可选的，参考图3，该激光投影设备还可以包括第一透镜组件50、第一二向色片601、荧光轮70、反射镜组件80、第二透镜组件90、滤色轮100、收光部件110、全内反射(total internal reflection，TIR)透镜120、数字微镜器件(digital micro mirror device，DMD)130和投影镜头140。该第一亮度传感器401可以设置在该蓝色激光器201的出光侧和第一透镜组件50之间。可选的，该收光部件110也可以称为光棒。
其中，该反射镜组件80可以包括第一反射镜801、第二反射镜802和第三反射镜803。该第二透镜组件90可以包括第一透镜901、第二透镜902和第三透镜903。
该蓝色激光器201出射的蓝色激光经过第一透镜组件50聚光，并透过第一二向色片601和荧光轮70的透明区，依次经过第一反射镜801、第二反射镜802和第三反射镜803的反射后。再次透过第一二向色片601，并经过第一透镜901聚光后，经过滤色轮100的透明区产生蓝色激光。
蓝色激光器201出射的蓝色激光经过第一透镜组件50聚光后，透过第一二向色片601，并投射到荧光轮70的黄色荧光粉区从而激发出黄色荧光。该黄色荧光被荧光轮70的金属基板反射，再次经过第一二向色片601反射，以及第一透镜901进行聚光。之后该黄色荧光经过滤色轮100滤色后产生红色荧光。
该蓝色激光器201出射的蓝色激光经过第一透镜组件50聚光后，透过第一二向色片601，并投射到荧光轮70的绿色荧光粉区从而激发出绿色荧光。该绿色荧光被荧光轮70的金属基板反射，再次经过第一二向色片601反射，以及第一透镜901进行聚光。之后该绿色荧光经过滤色轮100滤色后产生绿色荧光。
该经过滤色轮100产生的蓝色激光、红色荧光和绿色荧光三种基色光分时通过收光部件110进行匀光，并经过第二透镜902和第三透镜903整形后进入TIR透镜120全反射，经过DMD 130反射后再透过TIR透镜120，最后经过投影镜头140投射至显示屏幕上，形成需要显示的图像。
在本申请实施例另一种可选的实现方式中，参考图4和图5，该激光投影设备中的激 光光源20可以包括一组蓝色激光器201和一组红色激光器202，该激光投影设备可以称为双色激光投影设备。该至少一个亮度传感器40可以包括第一亮度传感器401和第二亮度传感器402。该第二亮度传感器402可以为红光亮度传感器和白光亮度传感器。
作为本申请一种可选的实现方式，该第一亮度传感器401设置在蓝色激光器201的出光侧，该第二亮度传感器402设置在红色激光器202的出光侧。
由于该激光器出射的激光在其出光侧并未出现衰减，将亮度传感器设置在激光器的出光侧，提高了亮度传感器对激光器第一亮度值检测的精度。
该显示控制电路10还用于在控制该蓝色激光器201出射蓝色激光时，读取该第一亮度传感器401检测的亮度值。并在控制该蓝色激光器201关闭时，停止读取该第一亮度传感器401检测的亮度值。
该显示控制电路10还用于在控制红色激光器202出射红色激光时，读取第二亮度传感器402检测的亮度值，并在控制红色激光器202关闭时，停止读取第二亮度传感器402检测的亮度值。
在激光投影设备投影图像的过程中，该第一亮度传感器401和第二亮度传感器402一直处于开启状态。
参考图5，该激光投影设备还可以包括收光部件110。作为本申请另一种可选的实现方式，该第一亮度传感器401设置在该蓝色激光器201的出光侧，该第二亮度传感器402设置收光部件110的出光侧。
该显示控制电路10还用于在红色激光器202出射红色激光时，读取第二亮度传感器402检测的亮度值，并在该红色激光器202关闭时，停止读取第二亮度传感器402检测的亮度值，以确保该第二亮度传感器402可以检测该红色激光器202的第一亮度值。
可选的，该显示控制电路10还用于在控制该蓝色激光器201出射蓝色激光时，读取该第一亮度传感器401检测的亮度值。并在控制该蓝色激光器201关闭时，停止读取该第一亮度传感器401检测的亮度值。
示例的，参考图4和图5，该激光投影设备还可以包括第一透镜组件50、第二二向色片602、第三二向色片603、荧光轮70、反射镜组件80、第二透镜组件90、滤色轮100、TIR透镜120、DMD 130和投影镜头140。
其中，该第一透镜组件50可以包括第四透镜501和第五透镜502。该反射镜组件80可以包括第一反射镜801、第二反射镜802和第四反射镜804。该第二透镜组件90可以包括第一透镜901、第二透镜902和第三透镜903。
在本申请实施例中，蓝色激光器201出射的蓝色激光经过第四透镜501聚光后，透过 第二二向色片602，并透过荧光轮70的透明区，经过第一反射镜801和第二反射镜802的连续反射，再次经过第三二向色片603反射，透过第二二向色片602，经过第一透镜901进行聚光后，透过滤色轮100的透明区进入收光部件110匀光后产生蓝色激光。
蓝色激光器201出射的蓝色激光经过第四透镜501聚光后，透过第二二向色片602，并投射到荧光轮70上的黄色荧光粉区从而激发出黄色荧光，该黄色荧光被荧光轮70的金属基板反射，再次经过第二二向色片602反射，以及第一透镜901聚光后，经过滤色轮100滤色并进入收光部件110匀光后产生黄色荧光。
蓝色激光器201出射的蓝色激光经过第四透镜501聚光后，透过第二二向色片602，并投射到荧光轮70上的绿色荧光粉区从而激发出绿色荧光，该绿色荧光被荧光轮70的金属基板反射，再次经过第二二向色片602反射，以及第一透镜901聚光后，经过滤色轮100滤色并进入收光部件110匀光后产生绿色荧光。
红色激光器202发出的红色激光经过第五透镜502聚光后，经过第四反射镜804反射，透过第三二向色片603和第二二向色片602直接进入第一透镜901，并经过滤色轮100的透明区进入收光部件110匀光得到红色激光。
该红色激光、蓝色激光、绿色荧光和黄色荧光四种基色光分时通过收光部件110匀光后，经过第二透镜902和第三透镜903整形后进入TIR透镜120全反射，并经过DMD 130反射后再透过TIR透镜120，最后经过投影镜头140投射至显示屏幕上，形成需要显示的图像。
在本申请又一种可选的实现方式中，参考图6和图7，该激光投影设备中的激光光源20可以包括独立设置的一组蓝色激光器201、一组红色激光器202和一组绿色激光器203，该激光投影设备通过设置可以发出三种基色光的激光器，从而可以不用再设置荧光轮等荧光转换装置。在一些实施方式中，也可以在三色激光器之外，再设置荧光转换装置，用于产生部分与激光种类同色异谱的荧光，以对同色的激光基色光进行补充。
以及，本示例中蓝色激光器201、红色激光器202和绿色激光器203均为MCL(multi_chip laser-diode，多芯片激光发光二极管)类型封装激光器，其体积小，利于光路的紧凑排布。
作为一种可选的实现方式，参考图6，该至少一个亮度传感器40可以包括第一亮度传感器401、第二亮度传感器402和第三亮度传感器403，该第三亮度传感器403为绿光亮度传感器或者白光亮度传感器。
其中，该第一亮度传感器401设置在蓝色激光器201的出光侧，该第二亮度传感器402设置在红色激光器202的出光侧，该第三亮度传感器403设置在绿色激光器203的出光侧。 由于该激光器出射的激光在其出光侧并未出现衰减，将亮度传感器设置在激光器的出光侧，提高了亮度传感器对激光器第一亮度值检测的精度。
该显示控制电路10还用于在控制蓝色激光器201出射蓝色激光时，读取该第一亮度传感器401检测的亮度值。并在控制该蓝色激光器201关闭时，停止读取该第一亮度传感器401检测的亮度值。
该显示控制电路10还用于在控制红色激光器202出射红色激光时，读取该第二亮度传感器402检测的亮度值，并在控制红色激光器202关闭时，停止读取第二亮度传感器402检测的亮度值。
该显示控制电路10还用于在控制绿色激光器203出射绿色激光时，读取该第三亮度传感器403检测的亮度值，并在控制绿色激光器203关闭时，停止读取该第三亮度传感器403检测的亮度值。
参考图7，该激光投影设备还可以包括收光部件110，作为另一种可选的实现方式，该至少一个亮度传感器40可以包括第四亮度传感器404，该第四亮度传感器404可以为白光亮度传感器。其中，该第四亮度传感器404设置在收光部件110的出光侧。
该显示控制电路10还用于在控制蓝色激光器201、红色激光器202和绿色激光器203分时开启时，读取该第四亮度传感器404检测的亮度值，以确保该第四亮度传感器404可以检测到该蓝色激光器201的第一亮度值、该红色激光器202的第一亮度值和该绿色激光器203的第一亮度值。并在控制该蓝色激光器201、红色激光器202和绿色激光器203均关闭时，停止读取该第四亮度传感器404检测的亮度值。
在激光投影设备投影图像的过程中，该第四亮度传感器404一直处于开启状态。
示例的，参考图6和图7，该激光投影设备还可以包括第四二向色片604、第五二向色片605、第五反射镜904、第二透镜组件90、扩散轮150、TIR透镜120、DMD 130和投影镜头140。其中，该第二透镜组件90包括第一透镜901、第二透镜902和第三透镜903。该第四二向色片604可以透过蓝色激光，反射绿色激光。该第五二向色片605可以透过红色激光，反射绿色激光和蓝色激光。
该蓝色激光器201出射的蓝色激光透过第四二向色片604，再经过第五二向色片605反射进入第一透镜901聚光。红色激光器202出射的红色激光透过第五二向色片605直接进入第一透镜901聚光。绿色激光器203出射的绿色激光经过第五反射镜904反射，依次经过第四二向色片604和第五二向色片605反射后进入第一透镜901聚光。经过第一透镜901聚光后的蓝色激光、红色激光和绿色激光分时透过旋转的扩散轮150进行消散斑，并投射到收光部件110匀光后，经过第二透镜902和第三透镜903整形后进入TIR透镜120 全反射，并经过DMD 130反射后再透过TIR透镜120，最后经过投影镜头140投射至显示屏幕上，形成需要显示的图像。
在另一种可选的实现方式中，如图8和图9所示，该激光投影设备中的激光光源20可以为MCL型激光器，比如为一个MCL型激光器，其中该一个MCL型激光器如图12所示，包括基板2001，基板2001与周围框架形成内凹空间，基板2001的内上表面贴装有多个发光芯片，多个发光芯片可以发出红色，蓝色，绿色的激光。框体侧部引出引线端子，用于通电对激光器的发光芯片进行驱动，以及在发光芯片的出光面上方还覆盖有准直透镜组2003，具有多个准直透镜，分别一一对应发光芯片的出光光束。
在本示例中，通过一个MCL型激光器，就可以发出三色激光。具体地，该MCL激光器包括行列排布的发光芯片，可以包括两行红色激光器202、一行蓝色激光器201和一行绿色激光器203。该激光投影设备可以称为全色激光投影设备。该激光投影设备中的蓝色激光器203设置在红色激光器202和绿色激光器203的中间。由于蓝色激光器201所能承受的温度更高，因此将该蓝色激光器203设置在红色激光器202和绿色激光器203的中间，该设置方式更有利于红色激光器202和绿色激光器203的快速散热，使得该集成设置的多个激光器的可靠性更高。
作为一种可选的实现方式，亮度传感器40可以包括第一亮度传感器401、第二亮度传感器402和第三亮度传感器403。
其中，该第一亮度传感器401设置在蓝色激光器201的出光路径中，具体地，设置蓝色激光光束的准直光束出光路径一侧，而不遮挡光路，同理，该第二亮度传感器402设置在两行红色激光器202的准直光束出光路径中，具体地，设置在红色激光光束的出光路径一侧，该第三亮度传感器403设置在绿色激光器203的出光路径中，具体设置在设置绿色激光光束的准直光束出光路径一侧。
该显示控制电路10还用于在控制蓝色激光器201出射蓝色激光时，读取该第一亮度传感器401检测的亮度值。并在控制该蓝色激光器201关闭时，停止读取该第一亮度传感器401检测的亮度值。
该显示控制电路10还用于在控制红色激光器202出射红色激光时，读取该第二亮度传感器402检测的亮度值，并在控制红色激光器202关闭时，停止读取第二亮度传感器402检测的亮度值。
该显示控制电路10还用于在控制绿色激光器203出射绿色激光时，读取该第三亮度传感器403检测的亮度值，并在控制绿色激光器203关闭时，停止读取该第三亮度传感器403检测的亮度值。
其中，第一亮度传感器401可以是蓝光第一亮度传感器或者白光亮度传感器，第二亮度传感器402为红光亮度传感器或者白光亮度传感器，第三亮度传感器403为绿光亮度传感器或者白光亮度传感器。
以及，作为本申请的另一种实施方式，亮度传感器也可以为一个，设置于三色激光的合光路径中，比如合光反射镜805所反射的光路径中。
或者，参考图8，该激光投影设备还可以包括收光部件110，具体地，收光部件110可以为光导管。作为另一种可选的实现方式，该亮度传感器40可以包括第四亮度传感器404。其中，第四亮度传感器404设置在两个红色激光器202的出光路径中、蓝色激光器201的出光路径中和绿色激光器203的出光路径中。也即是，该第四亮度传感器404设置在激光光源20的出光路径中。或者，参考图4，该第四亮度传感器404设置在光导管110的出光路径中。
该显示控制电路10还用于在控制激光投影设备开始投影显示图像时，读取该第四亮度传感器404检测的亮度值。该第四亮度传感器404用于在蓝色激光器201出射蓝色激光时，检测该蓝色激光器201的第一亮度值。在红色激光器202出射红色激光时，检测该红色激光器202的第一亮度值。在绿色激光器203出射绿色激光时，检测该绿色激光器203的第一亮度值。并在控制激光投影设备停止投影显示图像时，停止读取该第四亮度传感器404检测的亮度值。
参考图8和图9，该激光投影设备还可以包括四个第五反射镜片805、第二透镜组件90、TIR透镜120、DMD 130、投影镜头140和扩散轮150。其中，该第二透镜组件90包括第一透镜901、第二透镜902和第三透镜903。每个激光器对应设置有一个第五反射镜片805。
蓝色激光器201出射的蓝色激光经过相应位置处的第五反射镜片805反射，并经过第一透镜901聚光，透过扩散轮150匀光，再经过光导管110进行全反射匀光。红色激光器202出射的红色激光经过相应位置处的第五反射镜片805反射，并经过第一透镜901聚光，透过扩散轮150对红色激光进行消散斑和色度匀光，再经过光导管110进行全反射匀光。绿色激光器202出射的绿色激光经过相应位置处的第五反射镜片805反射，并经过第一透镜901聚光，透过扩散轮150对绿色激光进行消散斑和色度匀光，再经过光导管110进行全反射匀光。经过光导管110匀光后的蓝色激光、红色激光和绿色激光分时经过第二透镜902和第三透镜903整形，并进入TIR透镜120全反射，经过DMD 130反射后再透过TIR透镜120，最后经过投影镜头140投射到显示屏幕上，形成需要显示的图像。
在本申请实施例中，参考图10，该激光器驱动组件30可以包括驱动电路301、开关 电路302和放大电路303。该驱动电路301可以为驱动芯片。该开关电路302可以为金属氧化物半导体(metal-oxide-semiconductor，MOS)管。
其中，该驱动电路301分别与开关电路302、放大电路303以及激光光源20所包括的对应的激光器连接。该驱动电路301用于基于显示控制电路10发送的电流控制信号通过VOUT端向激光光源20中对应的激光器输出驱动电流，并通过ENOUT端将接收到的使能信号传输至开关电路302。其中，该激光器可以包括串联的n个子激光器，分别为子激光器LD1至LDn。n为大于0的正整数。
开关电路302串联在激光器的电流通路中，用于在接收到的使能信号为有效电位时，控制电流通路导通。
放大电路303分别与激光光源20的电流通路中的检测节点E和显示控制电路10连接，用于将检测到的激光器组件201的驱动电流转换为驱动电压，放大该驱动电压，并将放大后的驱动电压传输至显示控制电路10。
显示控制电路10还用于将放大后的驱动电压确定为激光器的驱动电流，并获取该驱动电流对应的第二亮度值。
示例的，如图10所示，放大电路303可以包括：第一运算放大器A1、第一电阻(又称取样功率电阻)R1、第二电阻R2、第三电阻R3和第四电阻R4。
第一运算放大器A1的同相输入端(又称正端)与第二电阻R2的一端连接，第一运算放大器A1的反相输入端(又称负端)分别与第三电阻R3的一端和第四电阻R4的一端连接，第一运算放大器A1的输出端分别与第四电阻R4的另一端和处理子电路3022连接。第一电阻R1的一端与检测节点E连接，第一电阻R1的另一端与参考电源端连接。第二电阻R2的另一端与检测节点E连接，第三电阻R3的另一端与参考电源端连接。该参考电源端为接地端。
如图10所示，该第一运算放大器A1还可以包括两个电源端，其中一个电源端与电源端VCC连接，另一个电源端可以与参考电源端连接。
激光光源20所包括的激光器的较大的驱动电流通过第一电阻R1后产生压降，该第一电阻R1一端(即检测节点E)的电压V i通过第二电阻R2传输至第一运算放大器A1的同相输入端，经过第一运算放大器A1放大N倍后输出。该N为该第一运算放大器A1的放大倍数，且N为正数。该放大倍数率N可以使得第一运算放大器A1输出的电压V fb的数值为激光器的驱动电流的数值的整数倍。示例的，电压V fb的数值可以与该驱动电流的数值相等，从而便于显示控制电路10将该放大后的驱动电压确定为激光器的驱动电流。
本申请实施例中，该第一运算放大器A1的输入输出电压的放大公式为：
Figure PCTCN2021077665-appb-000001
V i为第一运算放大器A1的输入电压，V fb为第一运算放大器A1的输出电压。该第一运算放大器A1的放大倍数N满足：
Figure PCTCN2021077665-appb-000002
在本申请实施例中，该显示控制电路10、驱动电路301、开关电路302和放大电路303形成闭环，以实现对该激光器的驱动电流的反馈调节，从而使得该显示控制电路10可以通过激光器的第二亮度值与第一亮度值的差值，及时调节该激光器的驱动电流，也即是及时调节该激光器的实际发光亮度，避免激光器长时间发生COD故障，同时提高了对激光器发光控制的准确度。
需要说明的是，参考图6和图7，若激光光源20包括一组蓝色激光器201、一组红色激光器202和一组绿色激光器203。该蓝色激光器201可以设置在L1位置处，该红色激光器202可以设置在L2位置处，绿色激光器203可以设置在L3位置处。
参考图6和图7，L1位置处的激光经过第四二向色片604一次透射，再经过第五二向色片605反射一次后进入第一透镜901中。该L1位置处的光效率P1＝Pt×Pf。其中，Pt表示的是二向色片的透射率，Pf表示的是二向色片或者第五反射率904的反射率。
表1示出了每种激光透过每个二向色片的透射率Pt以及被每个二向色片或者第五反射镜904反射的反射率。示例的，如表1所示，红色激光透过每个二向色片的透射率为97％，红色激光被每个二向色片或第五反射镜904反射的反射率为99％。
参考表1，在L1位置处，蓝色激光的光效率为96.5％×99％＝95.535％。红色激光的光效率为97％×99％＝96.03％，绿色激光的光效率为96.5％×99％＝95.535％。即在L1位置处红色激光的光效率最高，蓝色激光和绿色激光的光效率最低，均为95.535％。在L1位置处的最大光效率为96.03％。
L2位置处的激光只需经过第五二向色片605一次透射即可进入第一透镜901中，该L2位置处的光效率P2＝Pt。
参考表1，蓝色激光的光效率为96.5％，红色激光的光效率为97％，绿色激光的光效率为96.5％，即在L1位置处红色激光的光效率最高。在L1位置处的最大光效率为97％。
L3位置处的激光经过第五反射镜904反射一次，经过第四二向色片604反射一次，再经过第五二向色片605反射一次后才进入第一透镜901中。该L3位置处的激光共进行了3次反射。该L3位置处的光效率P3＝Pf×Pf×Pf。
参考表1，由于蓝色激光、红色激光和绿色激光的反射率均为99％，因此蓝色激光、红色激光和绿色激光的光效率均为99％×99％×99％＝97.0299％。即在L3位置处蓝色激光、红色激光和绿色激光的光效率相同。在L1位置处的最大光效率为97.0299％。
表1
Figure PCTCN2021077665-appb-000003
由以上可知，在L1、L2和L3三个位置中，L3位置处的激光的光效率最高，L1位置处的激光的光效率最低。由于蓝色激光器201输出的最大光功率Pb＝4.5瓦(W)，红色激光器202输出的最大光功率Pr＝2.5W，绿色激光器203输出的最大光功率Pg＝1.5W。即蓝色激光器201输出的最大光功率最大，红色激光器202输出的最大光功率次之，绿色激光器203输出的最大光功率最小。因此将绿色激光器203设置在L3位置处，将红色激光器202设置在L2位置处，将蓝色激光器201设置在L1位置处。也即是将绿色激光器203设置在光效率最高的光路中，从而确保激光投影设备能够获得最高的光效率。
综上多个实施例，当激光投影设备的激光光源为单色激光光源时，在蓝色激光器的出光路径中，位于蓝色激光器的出光侧的蓝光亮度传感器可以将检测到的第一亮度值发送至显示控制电路。该显示控制电路可以获取该蓝色激光器的驱动电流对应的第二亮度值。并当在目标时长内该第二亮度值与第一亮度值之间的差值大于差值阈值，确定该蓝色激光器的亮度骤降，即该蓝色激光器发生COD故障，则显示控制电路可以将与该蓝色激光器对应的激光器驱动组件的电流控制信号的占空比调小，以降低蓝色激光器的驱动电流，直至该差值小于等于该差值阈值，从而消除该蓝色激光器的COD故障，恢复蓝色激光器的正常工作。
当该激光投影设备的激光光源为蓝红双色激光光源时，在蓝色激光器的出光路径中，位于蓝色激光器的出光侧的蓝光亮度传感器可以将检测到的第一亮度值发送至显示控制电路。该显示控制电路可以获取该蓝色激光器的驱动电流对应的第二亮度值。并当在目标时长内该第二亮度值与第一亮度值之间的差值大于差值阈值，确定该蓝色激光器的亮度骤降，即该蓝色激光器发生COD故障，则显示控制电路10可以将与该蓝色激光器对应的激光器驱动组件的电流控制信号的占空比调小，以降低激光器的驱动电流，直至该差值小于等于该差值阈值，从而消除该蓝色激光器的COD故障，恢复蓝色激光器的正常工作。
在红色激光器的出光路径中，位于红色激光器的出光侧的红光亮度传感器或者位于收光部件出光侧的白光亮度传感器可以将检测到的第一亮度值发送至显示控制电路。该显示控制电路可以获取该红色激光器的驱动电流对应的第二亮度值。并当在目标时长内该第二亮度值与第一亮度值之间的差值大于差值阈值，确定该红色激光器的亮度骤降，即该红色 激光器发生COD故障，则显示控制电路10可以将与该红色激光器对应的激光器驱动组件的电流控制信号的占空比调小，以降低红色激光器的驱动电流，直至该差值小于等于该差值阈值，从而消除该红色激光器的COD故障，恢复红色激光器的正常工作。
当激光投影设备的激光光源为三色激光光源时，在蓝色激光器的出光路径中，位于蓝色激光器的出光侧的蓝光亮度传感器或者位于收光部件的出光侧的白光亮度传感器可以将检测到的第一亮度值发送至显示控制电路。该显示控制电路可以获取该蓝色激光器的驱动电流对应的第二亮度值。并当在目标时长内该第二亮度值与第一亮度值之间的差值大于差值阈值，确定该蓝色激光器的亮度骤降，即该蓝色激光器发生COD故障，则显示控制电路10可以将与该蓝色激光器对应的激光器驱动组件的电流控制信号的占空比调小，以降低蓝色激光器的驱动电流，直至该差值小于等于该差值阈值，从而消除该蓝色激光器的COD故障，恢复蓝色激光器的正常工作。
在红色激光器的出光路径中，位于红色激光器的出光侧的红光亮度传感器或者位于收光部件的出光侧的白光亮度传感器可以将检测到的第一亮度值发送至显示控制电路。该显示控制电路可以获取该红色激光器的驱动电流对应的第二亮度值。并当在目标时长内该第二亮度值与第一亮度值之间的差值大于差值阈值，确定该红色激光器的亮度骤降，即该红色激光器发生COD故障，则显示控制电路10可以将与该红色激光器对应的激光器驱动组件的电流控制信号的占空比调小，以降低红色激光器的驱动电流，直至该差值小于等于该差值阈值，从而消除该红色激光器的COD故障，恢复红色激光器的正常工作。
在绿色激光器的出光路径中，位于绿色激光器的出光侧的绿光亮度传感器或者位于收光部件的出光侧的白光亮度传感器可以将检测到的第一亮度值发送至显示控制电路。该显示控制电路可以获取该绿色激光器的驱动电流对应的第二亮度值。并当在目标时长内该第二亮度值与第一亮度值之间的差值大于差值阈值，则可以确定该绿色激光器的亮度骤降，即该绿色激光器发生COD故障，则显示控制电路可以将与该绿色激光器对应的激光器驱动组件的电流控制信号的占空比调小，以降低该绿色激光器的驱动电流，直至该差值小于等于该差值阈值，从而消除该绿色激光器的COD故障，恢复绿色激光器的正常工作。
综上可知，本申请提供的激光投影设备，可以应用上述多个示例中的激光光源。在示例方案中，可以及时发现激光器的故障，通过降低驱动电流及时干涉，防止该激光器长时间处于COD故障状态，促进激光器故障的修复。并且可以在故障排除后再进行正常PWM信号的输出，对激光器进行正常驱动，进行了闭环的自恢复控制，提高了激光光源使用的可靠性和稳定性，保证了投影画面的质量。
以上所述仅为本申请的可选实施例，并不用以限制本申请，凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (12)

  1. 一种激光投影设备，其特征在于，包括：显示控制电路、激光光源、至少一个激光器驱动组件以及至少一个亮度传感器，所述激光光源包括与所述至少一个激光器驱动组件一一对应的至少一组激光器；
    所述显示控制电路用于向所述至少一个激光器驱动组件输出基色使能信号以及基色电流控制信号，以驱动所述至少一组激光器发光，
    所述亮度传感器设置于所述激光光源的出光路径中，用于检测所述至少一组激光器的第一亮度值，并将所述第一亮度值发送至所述显示控制电路；
    所述显示控制电路，还用于获取每个所述激光器的驱动电流对应的第二亮度值，若所述激光器的第二亮度值与所述激光器的第一亮度值的差值大于差值阈值，调整与所述激光器对应的所述激光器驱动组件的电流控制信号，直至所述差值小于等于所述差值阈值。
  2. 根据权利要求1所述的激光投影设备，其特征在于，所述显示控制电路还用于，当在目标时长内，所述激光器的第二亮度值与所述激光器的第一亮度值的差值大于差值阈值时，降低与所述激光器对应的所述激光器驱动组件的电流控制信号的占空比；
    以及，用于当所述激光器的第二亮度值与所述激光器的第一亮度值的差值小于或等于所述差值阈值时，保持与所述激光器对应的所述激光器驱动组件的电流控制信号的占空比不变。
  3. 根据权利要求1所述的激光投影设备，其特征在于，
    所述调整与所述激光器对应的所述激光器驱动组件的电流控制信号，直至所述差值小于等于所述差值阈值具体包括：
    若所述激光器的第二亮度值减去所述激光器的第一亮度值的差值大于差值阈值，减小与所述激光器对应的所述激光器驱动组件的电流控制信号，直至所述差值小于等于所述差值阈值。
  4. 根据权利要求1所述的激光投影设备，其特征在于，所述激光光源包括：一组蓝色激光器；所述至少一个亮度传感器包括：第一亮度传感器；
    所述第一亮度传感器设置在所述蓝色激光器的出光侧。
  5. 根据权利要求4所述的激光投影设备，其特征在于，所述激光光源还包括：一组红色激光器；所述至少一个亮度传感器还包括：第二亮度传感器；
    所述第二亮度传感器设置在所述红色激光器的出光侧；
    所述显示控制电路还用于在控制所述红色激光器出射红色激光时，读取所述第二亮度传感器检测的亮度值，以及在控制所述红色激光器关闭时，停止读取所述第二亮度传感器检测的亮度值。
  6. 根据权利要求1所述的激光投影设备，其特征在于，所述激光光源包括：独立设置的一组蓝色激光器、一组红色激光器和一组绿色激光器；
    以及，所述激光投影设备还包括：收光部件；
    所述至少一个亮度传感器包括：第四亮度传感器，所述第四亮度传感器设置在所述收光部件的入光侧或出光侧。
  7. 根据权利要求6所述的激光投影设备，其特征在于，所述蓝色激光器、红色激光器、绿色激光器均为MCL型激光器，所述至少一个亮度传感器包括第一亮度传感器、第二亮度传感器、第三亮度传感器，分别设置于每个所述MCL激光器的准直光束出光路径一侧。
  8. 根据权利要求1所述的激光投影设备，其特征在于，所述激光光源包括至少一个呈阵列排布的激光器，用于发出蓝色激光、红色激光、绿色激光，所述亮度传感器为多个，分别设置在所述蓝色激光、红色激光、绿色激光的出光路径一侧。
  9. 根据权利要求7或8所述的激光投影设备，其特征在于，所述激光投影设备还包括：收光部件；所述至少一个亮度传感器包括：第四亮度传感器；
    所述第四亮度传感器设置在所述收光部件的出光侧。
  10. 根据权利要求6或9所述的激光投影设备，其特征在于，所述第四亮度传感器为白光亮度传感器。
  11. 根据权利要求1或2所述的激光投影设备，其特征在于，所述第一亮度值，所述第二亮度值均为光输出功率值，所述第一亮度值小于所述第二亮度值的50％。
  12. 根据权利要求1或2所述的激光投影设备，其特征在于，所述显示控制电路，还用于，当所述激光器的第二亮度值与所述激光器的第一亮度值的差值小于等于差值阈值时，恢复与所述激光器对应的所述激光器驱动组件的电流控制信号至初始值。
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