A projector control circuit, a projector, and a projector control method

Abstract

The application discloses a projector control circuit, a projector and a projector control method. The projector control circuit comprises a color wheel feedback circuit configured to feed back a color wheel rotating speed signal; a detection circuit connected with the color wheel feedback circuit, configured to receive the color wheel rotating speed signal and output a high-level signal when the color wheel rotating speed signal is greater than a preset value or output a low-level signal when the color wheel rotating speed signal is less than the preset value; and a light source module connected with the detection circuit, configured to keep closed when the low-level signal is received or keep opened when the high-level signal is received. The application adopts a pure hardware circuit to detect the color wheel rotating speed signal, controls the light source module to be opened when the color wheel rotating speed is large, guarantees normal start of the projector, controls the light source module to be closed when the color wheel rotating speed is small, and protects the color wheel. The application has high reliability and solves problems of abnormal start of the projector caused by instability of a processor, occupation of processor resources and the like in prior art.

Description

Technical Field

[0001] This application relates to the field of projection equipment technology, and in particular to a projector control circuit, a projector, and a projector control method. Background Technology

[0002] The color wheel is one of the most crucial components in a projector system. It separates and filters the light source through a high-speed rotating wheel. The separated light beams are then refracted by other optomechanical elements, allowing the colors to be sequentially transmitted to the human eye. Based on the principle of visual persistence in the human brain, visual synthesis is then performed, resulting in a final image that is perceived by the viewer.

[0003] Since the color wheel is a key component for color separation in a projector's monochromatic light source, its lifespan and protection are crucial. Current technologies typically involve processor-based timing design within the projector system to protect the color wheel. However, timing design is complex, and poor design can damage the color wheel, leading to issues such as processor instability causing abnormal projector startup and excessive processor resource consumption. Summary of the Invention

[0004] Therefore, it is necessary to propose a projector control circuit, a projector, and a projector control method to address the above problems. This method can activate the light source module when the color wheel speed is high, ensuring the projector can start normally; and deactivate the light source module when the color wheel speed is low, protecting the color wheel.

[0005] In a first aspect, this application provides a projector control circuit, the circuit comprising:

[0006] Color wheel feedback circuit, used to provide feedback on the color wheel rotation speed signal;

[0007] The detection circuit is connected to the color wheel feedback circuit and is used to receive the color wheel rotation speed signal, and output a high-level signal when the color wheel rotation speed signal is greater than a preset value or output a low-level signal when the color wheel rotation speed signal is less than the preset value.

[0008] The light source module, connected to the detection circuit, is used to remain off when the low-level signal is received or to turn on when the high-level signal is received.

[0009] In some embodiments, the color wheel feedback circuit includes a comparator and an inverting circuit connected in sequence;

[0010] The comparator is used to convert the original color wheel rotation speed signal into a square wave signal;

[0011] The inverting circuit is used to invert the square wave signal to obtain the color wheel rotation speed signal.

[0012] In some embodiments, the inverting circuit includes a first hysteresis comparator, the negative input terminal of the first hysteresis comparator is used to input the square wave signal, and the positive input terminal of the first hysteresis comparator is connected to the internal power supply and the output terminal of the first hysteresis comparator respectively.

[0013] When the square wave signal is greater than the upper threshold of the first hysteresis comparator, the first hysteresis comparator outputs a low-level signal.

[0014] When the square wave signal is less than the lower threshold of the first hysteresis comparator, the first hysteresis comparator outputs a high-level signal.

[0015] In some embodiments, the detection circuit includes a charging circuit and a comparison circuit connected in sequence;

[0016] The charging circuit is connected to the color wheel feedback circuit and is used to receive the color wheel rotation speed signal and charge itself.

[0017] The comparison circuit is connected to the light source module and is used to compare the charging voltage of the charging circuit with a preset voltage, and output a high-level signal when the charging voltage is greater than the preset voltage or output a low-level signal when the charging voltage is less than the preset voltage.

[0018] In some embodiments, the charging circuit includes an RC integral circuit and a second capacitor connected in sequence;

[0019] The RC integrator circuit is connected to the color wheel feedback circuit, and the second capacitor is connected to the comparator circuit.

[0020] In some embodiments, the detection circuit further includes a buffer circuit, which is connected to the color wheel feedback circuit and the charging circuit respectively, and is used to buffer the color wheel rotation speed signal.

[0021] In some embodiments, the detection circuit further includes a first transistor, the base of which is connected to the output of the comparator circuit, the collector of which is connected to the internal power supply and the light source module, and the emitter of which is grounded.

[0022] In some embodiments, the comparison circuit includes a second hysteresis comparator, the negative input terminal of the second hysteresis comparator is used to input the charging voltage, and the positive input terminal of the second hysteresis comparator is connected to the internal power supply and the output terminal of the second hysteresis comparator, respectively.

[0023] When the charging voltage is greater than the upper limit threshold of the second hysteresis comparator, the second hysteresis comparator outputs a low-level signal, the first transistor is turned off, and the collector of the first transistor is at a high level, thereby turning on the light source module.

[0024] When the charging voltage is less than the lower threshold of the second hysteresis comparator, the second hysteresis comparator outputs a high-level signal, the first transistor turns on, and the collector of the first transistor is at a low level, causing the light source module to turn off.

[0025] Secondly, this application also provides a projector, the projector including the projector control circuit as described in any of the first aspects.

[0026] Thirdly, embodiments of this application also provide a projector control method, applied to a projector control circuit as described in any of the first aspects, the method comprising:

[0027] Detect the color wheel rotation speed signal;

[0028] When the color wheel rotation speed signal is greater than a preset value, the light source module is turned on; or,

[0029] When the color wheel rotation speed signal is less than the preset value, the light source module is controlled to turn off.

[0030] The embodiments of this application have at least the following beneficial effects:

[0031] The projector control circuit of this application embodiment includes: a color wheel feedback circuit for feeding back the color wheel rotation speed signal; a detection circuit connected to the color wheel feedback circuit for receiving the color wheel rotation speed signal and outputting a high-level signal when the color wheel rotation speed signal is greater than a preset value or outputting a low-level signal when the color wheel rotation speed signal is less than a preset value; and a light source module connected to the detection circuit for remaining off when a low-level signal is received or turning on when a high-level signal is received. This application embodiment uses a purely hardware circuit to detect the color wheel rotation speed signal and control the light source module. When the color wheel rotation speed is high, the light source module is turned on to ensure normal projector startup; when the color wheel rotation speed is low, the light source module is turned off to protect the color wheel. This provides high reliability and does not involve processor timing design, thus solving the problems of processor instability leading to abnormal projector startup and excessive processor resource consumption in existing technologies using processor-based software timing designs. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] in:

[0034] Figure 1 This is a schematic diagram of the first structure in the prior art;

[0035] Figure 2 This is a schematic diagram of the second structure in the prior art;

[0036] Figure 3 This is a schematic diagram of the structure of the projector control circuit in one embodiment of this application;

[0037] Figure 4 This is a schematic diagram of the color wheel feedback circuit in one embodiment of this application;

[0038] Figure 5 This is a circuit diagram of an inverting circuit in one embodiment of this application;

[0039] Figure 6 This is a circuit diagram of the detection circuit in one embodiment of this application;

[0040] Figure 7 This is a flowchart illustrating a projector control method in one embodiment of this application. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0042] In existing technologies, protecting the color wheel typically involves processor-based timing design of the projector system to achieve this purpose. However, timing design is quite complex, and poor design can lead to damage to the color wheel, as well as issues such as processor instability causing abnormal projector startup and excessive processor resource consumption.

[0043] Specifically, after the color wheel is driven, it sends a rotation speed signal to the processor. The rotation speed of the color wheel increases from low to high, and the rotation speed is detected by photoelectric devices on the color wheel. Typically, the processor uses one of two processing methods.

[0044] Figure 1 This is a schematic diagram of the first structure in the prior art. Please refer to... Figure 1 Instead of processing the color wheel feedback signal, the processor delays it by a few seconds before controlling the startup of the light source module via the processor's GPIO2 port. This method only performs a delay, which can lead to inconsistencies between ICs, potentially damaging the color wheel. Furthermore, the delay of a few seconds can affect the projector's startup time, thus impacting the user experience.

[0045] Figure 2 This is a schematic diagram of a second structural design in the prior art. Please refer to... Figure 2 After receiving the color wheel feedback signal from the processor's GPIO1 port, the processor detects the feedback signal. Once the rotation speed reaches its maximum, the processor's GPIO2 then controls the start of the light source module. This method requires the processor's GPIO ports to constantly detect the color wheel's rotation speed and control the light source module, consuming processor resources and depending on the processor's stability. If the GPIO ports fail, the rotation speed cannot be read, leading to abnormal startup of the color wheel and light source. Furthermore, this method also carries the risk of damaging the color wheel if the GPIO ports fail.

[0046] To address the aforementioned issues, this application provides a projector control circuit, a projector, and a projector control method. It primarily utilizes hardware circuitry to detect the color wheel rotation speed and activate the light source module. It does not involve the processor continuously reading the color wheel rotation speed via GPIO ports. The light source module is activated only when the color wheel rotation speed f reaches a certain value, and deactivated when the rotation speed drops to a certain value. This prevents the color wheel from being exposed to strong light at low speeds, which could reduce its lifespan or cause it to burn out, thus protecting the color wheel.

[0047] The technical solutions shown in this application will now be described in detail through specific embodiments. It should be noted that the following embodiments may exist independently or in combination with each other; identical or similar content will not be repeated in different embodiments.

[0048] In a first aspect, embodiments of this application provide a projector control circuit. Figure 3 This is a schematic diagram of the projector control circuit in one embodiment of this application. Please refer to... Figure 3 In some embodiments, the projector control circuit includes a color wheel feedback circuit 100, a detection circuit 200, and a light source module 300.

[0049] The color wheel feedback circuit 100 is connected to the color wheel of the projector and receives the color wheel rotation speed signal from the color wheel, feeding it back to the detection circuit 200. The detection circuit 200 is connected to the color wheel feedback circuit 100 and receives the color wheel rotation speed signal. It outputs a high-level signal to the light source module 300 when the color wheel rotation speed signal is greater than a preset value, or outputs a low-level signal to the light source module 300 when the color wheel rotation speed signal is less than the preset value. The light source module 300 is connected to the detection circuit 200 and remains off when it receives a low-level signal or turns on when it receives a high-level signal.

[0050] This application uses a pure hardware circuit to detect the color wheel rotation speed signal and control the light source module. When the color wheel rotation speed is high, the light source module is turned on to ensure the projector starts up normally; when the color wheel rotation speed is low, the light source module is turned off to protect the color wheel. This method has high reliability and solves the problems of processor instability and abnormal projector startup and processor resource consumption caused by processor-based software timing design in the prior art.

[0051] In some embodiments, the color wheel feedback circuit 100 includes a comparator and an inverting circuit connected in sequence. The comparator is used to convert the original color wheel rotation speed signal into a square wave signal. The inverting circuit is used to invert the square wave signal to obtain the color wheel rotation speed signal.

[0052] Figure 4 This is a schematic diagram of the color wheel feedback circuit in one embodiment of this application. Please refer to... Figure 4 In some embodiments, the negative input of comparator 110 is used to input a reference level Vref, and the positive input of comparator 110 is used to input the original color wheel rotation speed signal. Comparator 110 is used to filter the portion of the original color wheel rotation speed signal that is higher than the reference level Vref to obtain a square wave signal. Inverting circuit 120 is used to invert the square wave signal to obtain the color wheel rotation speed signal, which is also a square wave signal.

[0053] In some embodiments, if the comparator 110 outputs a square wave signal with a 10% duty cycle, the square wave signal is inverted by the inverting circuit 120 and then outputs a square wave signal with a 90% duty cycle, which is the color wheel speed signal.

[0054] Figure 5 This is a circuit diagram of the inverting circuit in one embodiment of this application. Please refer to... Figure 5In some embodiments, the inverting circuit 120 includes a first hysteresis comparator U1A. The negative input terminal of the first hysteresis comparator U1A is used to input a square wave signal, and the positive input terminal of the first hysteresis comparator U1A is connected to an internal 3.3V power supply and the output terminal of the first hysteresis comparator U1A, respectively. The output terminal of the first hysteresis comparator U1A is used to output a color wheel rotation speed signal. The first hysteresis comparator U1A can reduce interference from glitches in the square wave signal.

[0055] In some embodiments, the duty cycle of the initial speed signal is generally small, resulting in a relatively small voltage detected by the subsequent hardware circuitry, which is inconvenient for detection and calculation. Therefore, inverting the speed signal with a small duty cycle before inputting it to the subsequent hardware circuitry facilitates detection and calculation.

[0056] Please refer to Figure 5 The inverting circuit 120 also includes an external circuit consisting of a third resistor R3, a fourth resistor R4, an eleventh resistor R11, a twelfth resistor R12, and a third capacitor C3. One end of the third resistor R3 is connected to one end of the fourth resistor R4, one end of the twelfth resistor R12, and the non-inverting input of the first hysteresis comparator U1A. The other end of the third resistor R3 is connected to an internal 3.3V power supply. The other end of the fourth resistor R4 is grounded. The other end of the twelfth resistor R12 is connected to the output of the first hysteresis comparator U1A. One end of the eleventh resistor R11 is connected to the internal 3.3V power supply, and the other end of the eleventh resistor R11 is connected to the output of the first hysteresis comparator U1A. One end of the third capacitor C3 is connected to the internal 3.3V power supply, and the other end of the third capacitor C3 is grounded.

[0057] Please refer to Figure 5 According to the circuit principle, the voltage Vth1 at the non-inverting input terminal of the first hysteresis comparator U1A is Vo1*(R4 / (R4+R12)+3.3*(R4 / (R3+R4)). Where Vo1 is the voltage at the output terminal of the first hysteresis comparator U1A.

[0058] When Vo1 outputs a high-level signal (3.3V), the upper limit threshold of the first hysteresis comparator U1A is: Vth1up = 3.3*(10 / 110)+3.3*0.5 = 1.95V.

[0059] When Vo1 outputs a low-level signal (0V), the lower threshold of the first hysteresis comparator U1A is: Vth1down = 0*(10 / 110)+3.3*0.5 = 1.65V.

[0060] Therefore, when the square wave signal is greater than the upper threshold of 1.95V of the first hysteresis comparator U1A, the first hysteresis comparator U1A outputs a low-level signal; when the square wave signal is less than the lower threshold of 1.65V of the first hysteresis comparator U1A, the first hysteresis comparator U1A outputs a high-level signal, thereby inverting the square wave signal.

[0061] In some embodiments, the above-mentioned upper and lower thresholds can be adjusted according to the specific color wheel; only the adjustment is needed. Figure 5 The resistance values ​​of resistors R3, R4, and R12 can be determined.

[0062] In some embodiments, the first hysteresis comparator U1A is of model LM393.

[0063] Figure 6 This is a circuit diagram of the detection circuit in one embodiment of this application. Please refer to... Figure 6 In some embodiments, the detection circuit 200 includes a charging circuit 210 and a comparison circuit 220 connected in sequence, and also includes a buffer circuit 230. The buffer circuit 230 is connected to both the color wheel feedback circuit 100 and the charging circuit 210, and is used to buffer the color wheel rotation speed signal. The charging circuit 210 is connected to the buffer circuit 230 and is used to receive the buffered color wheel rotation speed signal and charge itself. The comparison circuit 220 is connected to the charging circuit 210 and is used to compare the charging voltage of the charging circuit 210 with a preset voltage, and output a high-level signal when the charging voltage is greater than the preset voltage or output a low-level signal when the charging voltage is less than the preset voltage.

[0064] Please refer to Figure 6 The buffer circuit 230 includes a buffer U2 and a fourth capacitor C4. Pin 2 of the buffer U2 is connected to the output of the color wheel feedback circuit 100, and pin 4 of the buffer U2 is connected to one end of the first resistor R1 of the charging circuit 210 and one end of the fourth capacitor C4, respectively. The other end of the fourth capacitor C4 is grounded. The color wheel speed signal passes through the buffer U2, which improves the rising and falling edges of the waveform, and the low level can be as low as 0V.

[0065] In some embodiments, the buffer U2 is model 74LVC1G125G.

[0066] The charging circuit 210 includes an RC integrator circuit and a second capacitor C2 connected in sequence. The RC integrator circuit is connected to the buffer U2, and the second capacitor C2 is connected to the comparator circuit 220.

[0067] The RC integrator circuit includes a first resistor R1 and a first capacitor C1, as well as a first diode D1 and a second diode D2. The first resistor R1 is connected to the first capacitor C1, and the first capacitor C1 is connected to the positive terminal of the first diode D1 and the negative terminal of the second diode D2. The negative terminal of the first diode D1 and the positive terminal of the second diode D2 are connected to the second capacitor C2.

[0068] When the voltage V1 at the output of buffer U2 is high, the first resistor R1 and the first capacitor C1 are fully charged, and the second capacitor C2 is charged through the second diode D2.

[0069] When the voltage V1 at the output of buffer U2 is low, since the voltage across the capacitor cannot change abruptly, the first diode D1 and the first capacitor C1 form a circuit until the second capacitor C2 is fully charged.

[0070] In some embodiments, the charging circuit 210 further includes a second resistor R2. The second resistor R2 is connected in parallel with the second capacitor C2.

[0071] In some embodiments, the comparator circuit 230 includes a second hysteresis comparator U1B. The negative input terminal of the second hysteresis comparator U1B is connected to the second capacitor C2 for inputting a charging voltage. The positive input terminal of the second hysteresis comparator U1B is connected to the internal 3.3V power supply and the output terminal of the second hysteresis comparator U1B, respectively.

[0072] In some embodiments, the second hysteresis comparator U1B is of model LM393.

[0073] In some embodiments, the comparator circuit 230 further includes an external circuit consisting of a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a fifth capacitor C5. One end of the fifth resistor R5, pin 8 of the second hysteresis comparator U1B, one end of the fifth capacitor C5, and one end of the eighth resistor R8 are all connected to an internal 3.3V power supply. The other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, one end of the seventh resistor R7, and the non-inverting input of the second hysteresis comparator U1B, respectively. The other end of the sixth resistor R6 is grounded. The other end of the seventh resistor R7 is connected to the output of the second hysteresis comparator U1B. The other end of the eighth resistor R8 is connected to the output of the second hysteresis comparator U1B and the ninth resistor R9, respectively. Pin 4 of the second hysteresis comparator U1B is grounded.

[0074] Please continue to refer to Figure 6 According to the circuit principle, the voltage Vth2 at the non-inverting input of the second hysteresis comparator U1B is Vo2*(R6 / (R6+R7)+3.3*(R6 / (R5+R6)). Where Vo2 is the voltage at the output of the second hysteresis comparator U1B.

[0075] When Vo2 outputs a high-level signal (3.3V), the upper limit threshold of the second hysteresis comparator U1B is: Vth2up = 3.3*(33 / 433)+3.3*(33 / 80) = 1.61V.

[0076] When Vo2 outputs a low-level signal (0V), the lower threshold of the second hysteresis comparator U1B is: Vth2down = 0*(33 / 433)+3.3*(33 / 80) = 1.36V.

[0077] Please continue to refer to Figure 6 The charging voltage across the second capacitor C2 is V3. According to circuit principles, the charging voltage V3 = V1 * (R2 * C1 * f / (1 + R2 * C1 * f)), where f is the rotational speed of the color wheel. Therefore, we can conclude:

[0078] V3=3.3*90%*(100000*0.1*0.000001*120 / (1+100000*0.1*0.000001*120))=2.97*(1.2 / (1+1.2)) = 1.62V.

[0079] The charging voltage V3 is input to the negative input terminal of the second hysteresis comparator U1B and compared with the upper threshold of the second hysteresis comparator U1B. When the charging voltage V3 is greater than the upper threshold of the second hysteresis comparator U1B (1.61V), pin 7 of the second hysteresis comparator U1B outputs a low-level signal.

[0080] When the color wheel speed decreases and the charging voltage V3 is lower than the lower threshold of 1.36V of the second hysteresis comparator U1B, pin 7 of the second hysteresis comparator U1B outputs a high-level signal.

[0081] Please continue to refer to Figure 6 In some embodiments, the detection circuit 200 further includes a first transistor Q1, the base of which is connected to the output of the comparator circuit 230, the collector of which is connected to an internal 3.3V power supply and an enable port, the enable port being connected to a light source module, and the emitter of which is grounded.

[0082] When pin 7 of the second hysteresis comparator U1B outputs a low-level signal, the first transistor Q1 is turned off (the first transistor Q1 is turned on by default when powered on, and the enable port LD_EN is low). At this time, the collector of the first transistor Q1 is high, and the enable port LD_EN is also high, which turns on the light source module and ensures that the projector is powered on normally.

[0083] When pin 7 of the second hysteresis comparator U1B outputs a high-level signal, the first transistor Q1 is turned on. At this time, the collector of the first transistor Q1 is at a low level, and the enable port LD_EN is also at a low level, which turns off the light source module to avoid burning out the color wheel and thus protect the color wheel.

[0084] In some embodiments, the first transistor Q1 can also be replaced by other switching components, such as MOSFETs, relays, etc.

[0085] In some embodiments, Figure 6 The circuit can adjust the component parameters according to the different rotational speeds f of the color wheels.

[0086] Combination Figures 3 to 6 The comparator in the color wheel feedback circuit 100 filters the portion of the original color wheel rotation speed signal that is higher than the reference level Vref, obtaining a square wave signal. This square wave signal is input to the first hysteresis comparator U1A for inversion, and then charges the second capacitor C2 through the RC integrator circuit. As the color wheel rotation speed frequency f increases, the charging voltage V3 on the second capacitor C2 increases until the charging voltage V3 exceeds the upper limit threshold of 1.61V of the second hysteresis comparator U1B. At this point, the second hysteresis comparator U1B outputs a low-level signal, the first transistor Q1 is turned off, and the enable port LD_EN is high, turning on the light source module and ensuring the projector powers on normally.

[0087] When the rotational speed of the color wheel decreases and the charging voltage V3 falls below the lower threshold of 1.36V of the second hysteresis comparator U1B, the second hysteresis comparator U1B outputs a high-level signal, the first transistor Q1 turns on, and the enable port LD_EN is at a low level, which turns off the light source module and prevents the color wheel from being exposed to strong light at low speed, thus protecting the color wheel from reduced service life and burnout.

[0088] It should be noted that the peripheral circuits in this embodiment, such as the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5, are conventional circuit configurations, and their functions are not described in detail. For example, the function of the third capacitor C3 is power supply filtering to ensure the stable operation of the first hysteresis comparator U1A.

[0089] In combination with the above, the projector control circuit of this application embodiment has the following beneficial effects:

[0090] 1. The color wheel rotation speed signal is detected and the light source module is controlled by pure hardware circuit. When the color wheel rotation speed is high, the light source module is turned on to ensure normal power-on of the projector; when the color wheel rotation speed is low, the light source module is turned off to protect the color wheel. This technology has high reliability and solves the problems of processor instability and abnormal power-on of the projector and excessive processor resources caused by the processor-based software timing design in the existing technology.

[0091] 2. Use the first hysteresis comparator to reduce signal glitches and interference.

[0092] 3. By utilizing the charging and discharging of the capacitor and the fact that the voltage across the capacitor cannot change abruptly, the output voltage value V3 at different color wheel rotation speeds can be calculated.

[0093] 4. Hardware parameters can be adjusted according to the different color wheel speeds of different projectors.

[0094] Secondly, embodiments of this application also provide a projector, including the projector control circuit as described in any embodiment of the first aspect.

[0095] In some embodiments, a projector control circuit is disposed in the projector, which also includes a color wheel and other necessary modules. The projector has at least the effects of the projector control circuit described in any embodiment of the first aspect, which will not be elaborated further here.

[0096] Thirdly, embodiments of this application also provide a projector control method, applied to a projector control circuit as described in any embodiment of the first aspect.

[0097] Figure 7 This is a flowchart illustrating a projector control method in one embodiment of this application. Please refer to... Figure 7 In some embodiments, the projector control method includes:

[0098] S110: Detects color wheel rotation speed signal;

[0099] S120: Controls the light source module to turn on when the color wheel speed signal is greater than a preset value; or,

[0100] S130: When the color wheel rotation speed signal is less than a preset value, control the light source module to turn off.

[0101] The color wheel feedback circuit in the projector's control circuit feeds back the color wheel rotation speed signal to the detection circuit. The detection circuit detects the color wheel rotation speed signal. When the color wheel rotation speed signal is greater than a preset value, it outputs a high-level signal to the light source module, turning on the light source module and ensuring the projector powers on normally. When the color wheel rotation speed signal is less than the preset value, it outputs a low-level signal to the light source module, turning off the light source module to prevent the color wheel from being exposed to strong light at low rotation speeds, which could reduce its lifespan or cause it to burn out, thus protecting the color wheel.

[0102] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A projector control circuit, characterized in that, The circuit includes: Color wheel feedback circuit, used to provide feedback on the color wheel rotation speed signal; The detection circuit is connected to the color wheel feedback circuit and is used to receive the color wheel rotation speed signal, and output a high-level signal when the color wheel rotation speed signal is greater than a preset value or output a low-level signal when the color wheel rotation speed signal is less than the preset value. A light source module, connected to the detection circuit, is used to remain off when the low-level signal is received or to turn on when the high-level signal is received; The detection circuit includes a charging circuit and a comparison circuit connected in sequence; The charging circuit is connected to the color wheel feedback circuit and is used to receive the color wheel rotation speed signal and charge itself. The comparison circuit is connected to the light source module and is used to compare the charging voltage of the charging circuit with a preset voltage, and output a high-level signal when the charging voltage is greater than the preset voltage or output a low-level signal when the charging voltage is less than the preset voltage. The detection circuit further includes a first transistor, the base of which is connected to the output terminal of the comparator circuit, the collector of which is connected to the internal power supply and the light source module, and the emitter of which is grounded. The comparison circuit includes a second hysteresis comparator. The negative input terminal of the second hysteresis comparator is used to input the charging voltage, and the positive input terminal of the second hysteresis comparator is connected to the internal power supply and the output terminal of the second hysteresis comparator, respectively. When the charging voltage is greater than the upper limit threshold of the second hysteresis comparator, the second hysteresis comparator outputs a low-level signal, the first transistor is turned off, and the collector of the first transistor is at a high level, thereby turning on the light source module. When the charging voltage is less than the lower threshold of the second hysteresis comparator, the second hysteresis comparator outputs a high-level signal, the first transistor turns on, and the collector of the first transistor is at a low level, causing the light source module to turn off.

2. The projector control circuit according to claim 1, characterized in that, The color wheel feedback circuit includes a comparator and an inverting circuit connected in sequence; The comparator is used to convert the original color wheel rotation speed signal into a square wave signal; The inverting circuit is used to invert the square wave signal to obtain the color wheel rotation speed signal.

3. The projector control circuit according to claim 2, characterized in that, The inverting circuit includes a first hysteresis comparator. The negative input terminal of the first hysteresis comparator is used to input the square wave signal. The positive input terminal of the first hysteresis comparator is connected to the internal power supply and the output terminal of the first hysteresis comparator, respectively. When the square wave signal is greater than the upper threshold of the first hysteresis comparator, the first hysteresis comparator outputs a low-level signal. When the square wave signal is less than the lower threshold of the first hysteresis comparator, the first hysteresis comparator outputs a high-level signal.

4. The projector control circuit according to claim 1, characterized in that, The charging circuit includes an RC integrating circuit and a second capacitor connected in sequence. The RC integrator circuit is connected to the color wheel feedback circuit, and the second capacitor is connected to the comparator circuit.

5. The projector control circuit according to claim 1, characterized in that, The detection circuit also includes a buffer circuit, which is connected to the color wheel feedback circuit and the charging circuit respectively, and is used to buffer the color wheel rotation speed signal.

6. A projector, characterized in that, Includes the projector control circuit as described in any one of claims 1 to 5.

7. A projector control method, characterized in that, The method, applied to a projector control circuit as described in any one of claims 1 to 5, comprises: Detect the color wheel rotation speed signal; When the color wheel rotation speed signal is greater than a preset value, the light source module is turned on; or, When the color wheel rotation speed signal is less than the preset value, the light source module is controlled to turn off.

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