A multi-mode switching projector

Abstract

The present invention relates to the technical field of projection equipment, and specifically discloses a projector capable of automatically adjusting audio parameters according to working modes and performing multi-mode switching. The projector comprises a main control unit with a CPU controller, an audio playback unit, a video playback unit and a graphic equalizer. The audio playback unit comprises an audio signal processing circuit connected to the CPU controller and a speaker for audio playback. The graphic equalizer adjusts the frequency and volume of a sound signal output by the audio signal processing circuit according to an instruction sent by the CPU controller. When the CPU controller receives a first control instruction, the video playback unit is controlled to work, and a first signal is sent to the graphic equalizer to control the audio signal processing circuit to output an audio signal according to a first audio model. When the CPU controller receives a second control instruction, the second signal is sent to the graphic equalizer to control the audio signal processing circuit to output an audio signal according to a second audio model.

Description

Technical Field

[0001] The present invention relates to the technical field of projection equipment, and in particular to a projector capable of automatically adjusting audio parameters according to working modes and performing multi-mode switching. Background Art

[0002] A projector is a device that can project images or videos onto a screen. It can be connected to computers, VCDs, DVDs, BDs, game consoles, DVs and other devices through different interfaces to play video signals from different signal sources. Early projectors were only used as video projection devices, and external speakers were required to play audio signals that matched the video. In this way, in order to obtain audio and video information at the same time, users needed to turn on multiple devices, which was cumbersome to operate and had high audio-visual costs. After technological innovation, projectors have now become a new type of playback device that integrates video and audio playback. Compared with traditional TVs, projectors are smaller in size, easier to carry, and have lower requirements for playback scenes. They can be instantly projected onto walls, screens or other obstacles for display, reducing the difficulty of viewing movies.

[0003] However, the audio playback module of a traditional projector is only used to work in conjunction with the video playback module, that is, the audio signal is played while the video is being shown. The projector cannot play audio alone, which makes it difficult to meet users' needs for multiple working modes of the projector. In addition, the audio parameters of a traditional projector require users to manually adjust them according to their own needs, which is cumbersome and not conducive to improving the user's audio-visual experience. Summary of the invention

[0004] Based on this, it is necessary to provide a projector that can automatically adjust audio parameters according to the working mode and switch between multiple modes to address the technical problem that the projector has a single function and requires manual adjustment of audio parameters.

[0005] A multi-mode switching projector, the multi-mode switching projector comprising a main control unit having a CPU controller, an audio playback unit, a video playback unit connected to the CPU controller, and a graphic equalizer, the audio playback unit comprising an audio signal processing circuit connected to the CPU controller and a speaker for receiving a signal output by the audio signal processing circuit and performing audio playback, the graphic equalizer being used to adjust the frequency and volume of a sound signal output by the audio signal processing circuit according to an instruction sent by the CPU controller;

[0006] When receiving the first control instruction, the CPU controller controls the video playback unit to work, and sends a first signal to the graphic equalizer, so that the graphic equalizer controls the audio signal processing circuit to output an audio signal according to the first audio model to enter the projection working mode;

[0007] When receiving the second control instruction, the CPU controller sends a second signal to the graphic equalizer, so that the graphic equalizer controls the audio signal processing circuit to output an audio signal according to a second audio model to enter an audio working mode.

[0008] In one embodiment, the frequency-volume curve of the first audio model is a saddle-shaped structure, and the frequency of the first audio model is a narrow-band frequency between 400 Hz and 2.3 kHz; the frequency-volume curve of the second audio model drops to a valley point after the volume gradually increases in the bass range, then rises, and the volume continues to rise in the treble range; the volume of the frequency-volume curve of the first audio model before the first drop and after the second drop is higher than the volume of the frequency-volume curve of the second audio model at the corresponding frequency.

[0009] In one of the embodiments, the projector further includes a voice acquisition module, and the voice acquisition module is used to collect sound signals in the environment and perform noise reduction processing on the sound signals.

[0010] In one of the embodiments, the voice collection module is a microphone array.

[0011] In one embodiment, the main control unit also includes a speech recognition module and a keyword recognition module. The speech recognition module is used to convert the speech information after noise reduction processing into text information; the keyword recognition module is constructed with a speech database containing several keywords, and the keyword recognition module is used to receive the text information sent by the speech recognition module and perform matching and recognition. When the text information matches any preset keyword in the speech database, the keyword recognition module sends a first control instruction or a second control instruction to the CPU controller.

[0012] In one embodiment, the projector further includes one or two command controls. When the number of command controls is one, the command control sends a first control instruction and a second control instruction to the CPU controller respectively under different operating conditions; when the number of command controls is two, the two command controls send a first control instruction and a second control instruction to the CPU controller respectively under predetermined operating conditions.

[0013] In one embodiment, the projector also includes an atmosphere light module, which includes a voltage-dividing resistor adjustment circuit connected to the CPU controller, an LED driving circuit connected to the voltage-dividing resistor adjustment circuit, and a light group circuit connected to the LED driving circuit. When receiving a second control instruction, the CPU controller sends an electrical signal to the voltage-dividing resistor adjustment circuit, and controls the LED driving circuit and the light group circuit to operate in sequence to perform atmosphere light projection.

[0014] In one of the embodiments, the projector further includes a data interface connected to the CPU controller, and the data interface supports HDMI and MHL dual interfaces.

[0015] In one embodiment, the projector further comprises a communication module connected to the CPU controller, and the communication module is connected to an external intelligent mobile device or a background server via a serial peripheral interface.

[0016] In one of the embodiments, the video playback unit includes a digital micromirror device (DMD) for receiving a video signal sent by the CPU controller and performing data processing.

[0017] The multi-mode switching projector of the present invention is implemented by setting a graphic equalizer in the projector and presetting a first audio model and a second audio model. During the operation of the projector, the CPU controller of the projector controls the video playback unit and the audio playback unit to work to enter the projection working mode, or controls the audio playback unit alone to work to enter the audio working mode when receiving different control instructions. When the projector is in different working modes, the sound signal output rules of the audio playback unit are different, so that the sound effect focus in different working modes is close to the user's needs. In this way, the projector can be used for audio and video playback and can also replace the audio. There is no need to manually adjust the working parameters of the projector, so as to meet the user's needs for sound effects in different working modes, enhance the user's audio-visual experience, and help improve the market competitiveness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the module structure of a projector in one embodiment of the present invention;

[0019] Figure 2 A frequency-volume curve comparison diagram of a first audio model and a second audio model in one embodiment of the present invention;

[0020] Figure 3 A mode switching logic diagram of a projector in one embodiment of the present invention;

[0021] Figure 4 is a circuit schematic diagram of a microphone array in one embodiment of the present invention;

[0022] Figure 5 is a circuit schematic diagram of an audio signal processing circuit in one embodiment of the present invention;

[0023] Figure 6 is a circuit schematic diagram of a voltage-dividing resistor adjustment circuit in one embodiment of the present invention;

[0024] Figure 7is a circuit schematic diagram of an LED driving circuit in one embodiment of the present invention;

[0025] Figure 8 is a circuit schematic diagram of a lamp assembly circuit in one embodiment of the present invention;

[0026] Fig. 9 is a circuit schematic diagram of a main control loop in one embodiment of the present invention;

[0027] Fig.10 FIG. 4 is a circuit schematic diagram of a DMD driving circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0029] The present invention provides a projector 10 that can automatically adjust audio parameters according to the working mode and switch between multiple modes. Specifically, a graphic equalizer 400 is set in the projector, and audio models under different working modes are preset, so that the audio playback unit 200 works with audio parameters with different characteristic rules in different working modes, so that the sound effect during audio playback is adapted to the working mode of the projector, thereby improving the user's audio-visual experience.

[0030] See also Figure 1The multi-mode switching projector 10 of the present invention comprises a main control unit 100 having a CPU controller 110, an audio playback unit 200 for audio playback, a video playback unit 300 connected to the CPU controller 110 and used for video playback, and a graphic equalizer 400. The audio playback unit 200 comprises an audio signal processing circuit 210 connected to the CPU controller 110 and a speaker 220 for receiving a signal output from the audio signal processing circuit 210 and performing audio playback. The graphic equalizer 400 is used to adjust the audio signal processing circuit 210 according to the instruction sent by the CPU controller 110. 0 output audio signal frequency and volume; when receiving the first control instruction, the CPU controller 110 controls the video playback unit 300 to work, and sends a first signal to the graphic equalizer 400, so that the graphic equalizer 400 controls the audio signal processing circuit 210 to output an audio signal according to the first audio model EQ1, so as to enter the projection working mode; when receiving the second control instruction, the CPU controller 110 sends a second signal to the graphic equalizer 400, so that the graphic equalizer 400 controls the audio signal processing circuit 210 to output an audio signal according to the second audio model EQ2, so as to enter the sound working mode. In this way, the projector adjusts the audio parameters according to different audio models in different working modes, so that the sound effect of the projector is adapted to the working mode.

[0031] See also Figure 2 , Figure 2 FIG. 4 shows a comparison of the frequency-volume curves (i.e., EQ curves) of the first audio model EQ1 and the second audio model EQ2. Figure 2 As shown, the frequency-volume curve of the first audio model EQ1 (such as Figure 2 The curve a) in the figure presents a saddle-shaped structure, that is, the frequency-volume curve of the first audio model EQ1 gradually rises to the first volume peak at a low frequency and then drops to the first volume valley, and then rises again to the second volume peak and then continues to drop. The frequency-volume curve of the first audio model EQ1 undergoes two rises and two drops. Furthermore, the frequency of the first audio model EQ1 is a narrowband frequency between 400Hz-2.3KHz. In this way, when the CPU controller 110 receives the first control instruction and switches the working mode of the projector to the projection working mode, the audio signal processing circuit 210 outputs at a lower volume in the bass area to facilitate the coordination of audio and video, and to prevent the user from focusing too much on the audio. In other words, the setting of the first audio model EQ1 improves the brightness of the timbre of the projector in the projection mode. The frequency-volume curve of the second audio model EQ2 (such as Figure 2Curve b) in the bass region gradually increases in volume and then drops to a valley point, then rises, and the volume in the treble region continues to rise; the volume of the frequency-volume curve of the first audio model EQ1 before the first drop and after the second drop is higher than the volume of the frequency-volume curve of the second audio model EQ2 at the corresponding frequency. In this way, when the projector switches to the audio working mode, the volume of the sound signal output by the speaker 220 is higher in the low-frequency section, and the volume continues to rise when entering the high-frequency section, so that the projector can improve the bass strength in the bass region and improve the sound transparency in the treble region to meet the demand for sound effects in the audio working mode of the projector.

[0032] See also Figure 3 , the control command input of the projector of this embodiment can be realized in two ways, one is to realize it by the mode switch (i.e., the command control 500), and the other is to realize it by the voice recognition. In the case of using the mode switch to input the control command, the projector includes one or two command controls 500. When the number of the command controls 500 is one, the command control 500 sends the first control command and the second control command to the CPU controller 110 respectively under different operating conditions; when the number of the command controls 500 is two, the two command controls 500 send the first control command and the second control command to the CPU controller 110 respectively under predetermined operating conditions. In other words, the user can use multiple different controls to input different commands to the CPU controller 110 respectively, and can also connect the switch corresponding to the same control to multiple control circuits, and achieve the purpose of inputting different commands to the CPU controller 110 by operating the same command control 500.

[0033] When the control command is obtained by voice recognition, the projector also includes a voice acquisition module 600, which is used to collect sound signals in the environment and perform noise reduction on the sound signals. Preferably, the voice acquisition module 600 is a microphone array. The microphone array is a system composed of multiple acoustic sensors, which is used to sample and process the spatial characteristics of the sound field. In the frequency response of the microphone array, an application similar to a spatial filter is formed according to the beam in the time domain, and the direction of the sound source of the received voice signal and its changes are analyzed. This type of analysis can be displayed in the form of a beam by a polar coordinate diagram. The intensity and angle of the voice signal, using this technology, can use the difference between the phases of the sound waves received by the two microphones to filter the sound waves, and can remove the environmental background sound to the maximum extent, leaving only the required sound waves, so that the purpose of collecting effective sound signals in a noisy environment can be achieved.

[0034] See also Figure 4In this embodiment, the microphone array includes two voice collection circuits, each of which includes a microphone for picking up sound signals in the environment. The ambient sound signals picked up by the microphone are processed by a filter circuit composed of a capacitor and an inductor, and then output through a relay J552 under the action of an electrostatic protection circuit, thereby obtaining a target sound wave that eliminates ambient noise.

[0035] Furthermore, the main control unit 100 also includes a speech recognition module 120 and a keyword recognition module 130. The speech recognition module 120 is used to convert the speech information after noise reduction processing into text information; the keyword recognition module 130 has a speech database containing several keywords built in it, and the keyword recognition module 130 is used to receive the text information sent by the speech recognition module 120 and perform matching and recognition. When the text information matches any preset keyword in the speech database, the keyword recognition module 130 sends a first control instruction or a second control instruction to the CPU controller 110. Preferably, the speech database includes a primary word library and a secondary word library, the primary word library includes single-word verbs or nouns such as "listen", "see", "visual", "shadow", "sound" and "audio" related to the working mode of the projector, and the secondary word library also stores auxiliary verbs, verbs or nouns directly related to mode switching for expressing wishes or results, such as "want to listen", "switch to see", "watch a movie" and other related phrases. In this way, after the speech recognition module 120 converts the speech information into text information, the keyword recognition module 130 first compares the text information with the speech data in the primary word library. If the text information does not match the speech data in the primary word library, the keyword recognition module 130 outputs a signal "0", and the CPU controller 110 does not perform the corresponding mode switching operation. If the text information matches one or more speech data in the primary word library, the speech recognition module 120 further matches and identifies the matching fields with the speech data in the secondary word library. Only when a matching field matches any speech data in the secondary word library, the keyword recognition module 130 outputs a signal "1" so that the CPU controller 110 performs the corresponding action. Specifically, the CPU controller 110 first determines whether the target working mode matches the current working mode. If so, the CPU controller 110 does not send a working instruction to the video playback unit 300 and / or the audio playback unit 200, that is, the current working mode is still maintained; if not, the CPU controller 110 sends a working instruction to the video playback unit 300 and / or the audio playback unit 200, and at the same time sends an electrical signal to the graphic equalizer 400 to switch the working mode of the projector.

[0036] See also Figure 5The audio signal processing circuit 210 of this embodiment includes a DSP chip, which has the advantages of a DSP (Digital Signal Process) chip and an AMP chip, and can perform digital signal processing. It adopts a Harvard structure in which programs and data are separated, has a dedicated hardware multiplier, widely adopts pipeline operations, and provides special DSP instructions, which can be used to quickly implement various digital signal processing algorithms; at the same time, it also serves as an amplifier, and can amplify data signals.

[0037] Please combine Figure 1 , Figure 6 , Figure 7 as well as Figure 8 In one embodiment, the projector further includes an atmosphere light module 700, which includes a voltage-dividing resistor adjustment circuit connected to the CPU controller 110, an LED driving circuit connected to the voltage-dividing resistor adjustment circuit, and a light group circuit connected to the LED driving circuit. When receiving the second control instruction, the CPU controller 110 sends an electrical signal to the voltage-dividing resistor adjustment circuit, and controls the LED driving circuit and the light group circuit to work in sequence to perform atmosphere light projection. The voltage-dividing resistor adjustment circuit is connected to the power supply circuit of the projector through the LED_POWER_EN pin, and is connected to the LED driving circuit through the LED_ADODE pin. The voltage-dividing resistor adjustment circuit is used to step down the voltage transmitted by the power supply circuit and adapt it to the working voltage of the LED light group. The LED driving circuit includes a power chip with a model number of MO8888 QFN28, that is, Figure 6 U6 in the lamp group circuit includes a plurality of lamp beads arranged on the lamp board, specifically including red, green and blue lamp beads. The power chip is also connected to the clock through the SCL / SCLK pin to control the flashing time or cycle of the lamp beads. When the projector switches to the audio working mode, the CPU controller 110 sends an electrical signal to the voltage divider resistor adjustment circuit, and enables the LED driving circuit to control each lamp bead to light up according to a predetermined rule, for example, the lamp beads light up in a predetermined order and limit the lighting time of a single lamp bead and the interval time between two lightings. Of course, the number of lamp beads can be increased or the color of the lamp beads can be changed according to actual needs to meet the audio-visual needs of users in the audio working mode.

[0038] In this embodiment, the CPU controller 110 and its peripheral components constitute a main control circuit. Figure 1 and Fig. 9The projector also includes a data interface 800 connected to the CPU controller 110, and the data interface 800 supports HDMI and MHL dual interfaces. The HDMI interface refers to the High Definition Multimedia Interface, which is a digital video / audio interface technology. It is a dedicated digital interface suitable for image transmission. It can transmit audio and image signals at the same time. The maximum data transmission speed is 2.25GB / s, and there is no need to perform digital / analog or analog / digital conversion before signal transmission; the MHL interface (Mobile High-Definition Link) is a mobile terminal high-definition audio and video standard interface. It is a standard audio and video interface for connecting portable consumer electronic devices. The MHL interface only uses a signal cable and can be presented on a high-definition TV through a standard HDMI input interface. By integrating the HDMI interface and the MHL interface on the same data interface 800, users can select the corresponding connection cable to be plugged into the data interface 800 to realize data transmission according to their needs, reducing the number of interfaces on the projector and being more conducive to shaping the external structure of the projector.

[0039] Further, the projector also includes a communication module 900 connected to the CPU controller 110, and the communication module 900 is connected to an external intelligent mobile device or a background server through a serial peripheral interface. Preferably, the communication module 900 is a WIFI signal transceiver, so that the CPU controller 110 can load audio and / or video from the background server regularly through the communication module 900 to instantly update the audio and video playback source in the projector. In addition, on the one hand, the user can send a control instruction to the CPU controller 110 through an intelligent mobile terminal such as a mobile phone or a tablet computer connected to the communication module 900 to remotely control the work of the projector, and on the other hand, the relevant application APP can also be loaded on an intelligent mobile terminal such as a mobile phone, and the APP is associated with the background server. In this way, the user can enter the password of the corresponding account in the APP for identity authentication, and realize the account binding with the background server to obtain audio and video permissions, and then load the audio and video into the CPU controller 110 of the projector through the operation in the mobile phone APP to increase the playback source of the projector.

[0040] In one embodiment, the video playback unit 300 includes a digital micromirror device DMD for receiving a video signal sent by the CPU controller 110 and performing data processing. Specifically, the digital micromirror device DMD is used to adjust the clarity, brightness and contrast of a predetermined image and output a projection light with specified parameters. When the projector enters the projection working mode, the LCD screen of the video playback unit 300 displays a predetermined image under the control of the CPU controller 110. At the same time, the light generated by the light source in the video playback unit 300 when working passes through the LCD screen and projects the predetermined image on the LCD screen onto the digital micromirror device DMD to output projection light with predetermined image parameters. The LCD screen includes two parallel glass substrates, a liquid crystal box arranged between the two glass substrates, a TFT (thin film transistor) arranged on one of the glass substrates, and a color filter arranged on the other glass substrate. When the LCD screen works under the action of the CPU controller 110, the signal and voltage transmitted from the CPU controller 110 to the TFT change, thereby controlling the rotation direction of the liquid crystal molecules in the liquid crystal box, thereby achieving the purpose of controlling whether the polarized light of each pixel point is emitted or not to display the image. The digital micromirror device chip can be regarded as a semiconductor optical switch with hundreds of thousands or even millions of micromirrors inside. Each micromirror represents a pixel, and the conversion rate is as high as 1000 times / second. In order to adjust its direction and angle, a hinge-like rotating device is provided below it. The rotation of the micromirror is controlled by the digital drive signal from the CMOS RAM. When the digital signal is written into the SRAM, static electricity activates the address electrode, the lens and the yoke plate to cause the hinge device to rotate. Once the corresponding signal is received, the lens tilts 10° and tilts +12° with the digital signal from the SRAM; if the microscope is in a non-projection state, it is shown as "off" and tilted -12°. In short, the working principle of DMD is to reflect the required light with the help of the micromirror device, and absorb the unnecessary light through the light absorber to realize the projection of the image, so as to adjust the clarity, brightness and contrast of the predetermined image and output the projection light with specified parameters.

[0041] See also Fig.10The projector also includes a DMD driving circuit for controlling the operation of the digital micromirror device DMD. The DMD driving circuit includes a relay J12. The relay J12 is provided with 15 pins DMD_D0-DMD_D14, etc., which are respectively connected to the diodes. The DMD driving circuit also includes a plurality of sub-circuits for adjusting DMD_VREF, DMD_VCC, DMD_VBIAS, DMD_VRST and DMD_VOFS. Each sub-circuit is respectively connected to the 50th pin, the 9th pin, the 38th pin, the 42nd pin and the 48th pin of the relay J12. Among them, the sub-circuits for adjusting DMD_VBIAS, DMD_VRST and DMD_VOFS respectively include two parallel capacitors. In the sub-circuit for adjusting DMD_VCC, the voltage is first processed by the inductor FB134 before being connected, and then enters the loop of the two parallel capacitors for further processing. In the sub-circuit for adjusting DMD_VREF, the two capacitors are connected in series and in parallel with the inductor to realize filtering processing of the reference voltage.

[0042] The multi-mode switching projector 10 of the present invention is implemented by setting a graphic equalizer 400 in the projector and presetting a first audio model EQ1 and a second audio model EQ2. During the operation of the projector, the CPU controller 110 of the projector controls the video playback unit 300 and the audio playback unit 200 to work to enter the projection working mode, or controls the audio playback unit 200 alone to work to enter the audio working mode when receiving different control instructions. When the projector is in different working modes, the sound signal output rules of the audio playback unit 200 are different, so that the sound effect focus in different working modes is close to the user's needs. In this way, the projector can be used for audio and video playback, and can also replace the audio. There is no need to manually adjust the working parameters of the projector, so as to meet the user's needs for sound effects in different working modes, enhance the user's audio-visual experience, and help improve the market competitiveness of the product.

[0043] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0044] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A multi-mode switching projector, characterized in that: It comprises a main control unit having a CPU controller, an audio playback unit, a video playback unit connected to the CPU controller, and a graphic equalizer, wherein the audio playback unit comprises an audio signal processing circuit connected to the CPU controller and a speaker for receiving a signal output from the audio signal processing circuit and performing audio playback, and the graphic equalizer is used to adjust the frequency and volume of the sound signal output by the audio signal processing circuit according to the instruction sent by the CPU controller; When receiving the first control instruction, the CPU controller controls the video playback unit to work, and sends a first signal to the graphic equalizer, so that the graphic equalizer controls the audio signal processing circuit to output an audio signal according to the first audio model to enter the projection working mode; When receiving the second control instruction, the CPU controller sends a second signal to the graphic equalizer, so that the graphic equalizer controls the audio signal processing circuit to output an audio signal according to the second audio model to enter the audio working mode; The frequency-volume curve of the first audio model is a saddle-shaped structure, and the frequency of the first audio model is a narrowband frequency between 400 Hz and 2.3 kHz; the frequency-volume curve of the second audio model drops to a valley point after the volume gradually increases in the bass range, then rises, and the volume in the treble range continues to rise; the volume of the frequency-volume curve of the first audio model before the first drop and after the second drop is higher than the volume of the frequency-volume curve of the second audio model at the corresponding frequency; It also includes a voice collection module, which is used to collect sound signals in the environment and perform noise reduction processing on the sound signals; The main control unit also includes a speech recognition module and a keyword recognition module. The speech recognition module is used to convert the speech information after noise reduction processing into text information; a speech database containing several keywords is constructed in the keyword recognition module. The keyword recognition module is used to receive the text information sent by the speech recognition module and perform matching and recognition. When the text information matches any preset keyword in the speech database, the keyword recognition module sends a first control instruction or a second control instruction to the CPU controller.

2. The multi-mode switching projector according to claim 1, characterized in that: The voice collection module is a microphone array.

3. The multi-mode switching projector according to claim 1, characterized in that: It also includes one or two instruction controls. When the number of instruction controls is one, the instruction control sends the first control instruction and the second control instruction to the CPU controller respectively under different operating conditions; when the number of instruction controls is two, the two instruction controls send the first control instruction and the second control instruction to the CPU controller respectively under predetermined operating conditions.

4. The multi-mode switching projector according to claim 3, characterized in that: It also includes an atmosphere light module, which includes a voltage-dividing resistor adjustment circuit connected to the CPU controller, an LED driving circuit connected to the voltage-dividing resistor adjustment circuit, and a light group circuit connected to the LED driving circuit. When receiving a second control instruction, the CPU controller sends an electrical signal to the voltage-dividing resistor adjustment circuit, and controls the LED driving circuit and the light group circuit to work in sequence to perform atmosphere light projection.

5. The multi-mode switching projector according to claim 1, characterized in that: The projector also includes a data interface connected to the CPU controller, and the data interface supports HDMI and MHL dual interfaces.

6. The multi-mode switching projector according to claim 1, characterized in that: The projector further comprises a communication module connected to the CPU controller, and the communication module is connected to an external intelligent mobile device or a background server through a serial peripheral interface.

7. The multi-mode switching projector according to claim 1, characterized in that: The video playback unit includes a digital micromirror device (DMD) for receiving a video signal sent by the CPU controller and performing data processing.

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