CN1315036C - Portable equipment video switching equipment and switching method thereof - Google Patents

Abstract

The invention discloses a video switching device of a portable device, comprising: an external video detection unit, a video signal conversion unit and a video output unit; the external video detection and video signal conversion units are respectively connected to the video output unit, and the external video detection unit is To detect whether a large-screen display device is connected, the video signal conversion unit receives the data stream from the portable device, converts it and outputs it to the video output unit, and then outputs it to the large-screen display device. The video switching device and switching method for portable equipment proposed by the present invention realize the connection of portable equipment such as portable computers, MP3, MD and PDA with TVs, projectors and other large-screen display devices that support VGA and AV, and perform large-screen display ; The present invention realizes the monitoring function of the external equipment through the external video detection unit, and reduces the energy consumption to the greatest extent; and makes the control more convenient by being compatible with general-purpose remote control boards such as TVs and DVD players.

Description

Portable device video switching device and switching method

technical field

The present invention relates to a video switching device and switching method for portable equipment, in particular to a switching device and switching method for video switching between portable equipment such as a portable computer and a large-screen display device such as a TV with a monitoring function . It belongs to the field of computer and its peripheral equipment.

Background technique

With the widespread application of digital technology and the emergence of large-capacity and small-volume storage devices, more and more functions are integrated into portable devices such as portable computers. Massive data and materials, including multimedia, are stored and viewed using portable devices such as portable computers.

These portable devices such as portable computers have small display screens for the convenience of carrying. In actual use, especially when playing video and viewing image files, the effect is not as good as that of a large-screen display device. Especially in some cases, it is necessary to display to the public, such as playing video files, animations and other video files in the computer, and viewing image files such as flow charts and renderings stored in the computer, because the display screen is too small, it is almost impossible to conduct. And although large-screen display devices such as TVs are easy to obtain, they cannot be easily connected with large-screen display devices such as portable computers and TVs, and the purpose of large-screen display cannot be reached.

Contents of the invention

In view of the above requirements, to solve the problem of convenient connection between portable devices such as portable computers and large-screen display devices such as TVs, the present invention proposes a video adapter device for portable devices, which can easily connect portable devices such as portable computers and PDAs with Large-screen display devices such as TVs and projectors are connected to display on a large screen; the video adapter device for portable equipment of the present invention has also taken monitoring measures to reduce energy consumption; It is a function compatible with general remote control boards such as mobile phones.

In order to better accomplish the purpose of the invention, the present invention also proposes a method for switching between a portable device and a large-screen display device.

The object of the present invention is achieved through the technical solutions described below.

A video switching device for a portable device, comprising: an external video detection unit, a video signal conversion unit and a video output unit;

The external video detection unit is connected with the video output unit, and the information of whether there is a large-screen display device is obtained through the output interface of the video output unit for connecting the large-screen display device, and the video signal conversion unit is connected with the video output unit, and the converted The data stream is sent to the video output unit;

The external video unit is provided with an interface connected to the portable device, which is used to send the information of whether there is a large-screen display device to the portable device;

The video signal conversion unit is provided with a command interface connected to the portable device for receiving various control commands from the portable device and a video interface connected to the portable device for receiving the data stream to be played from the portable device.

In the above-mentioned video switching device for portable devices, the external video detection unit includes at least one voltage comparison chip, one input terminal of the voltage comparison chip is connected to the output interface of the video output unit, and the other is connected to the standard voltage of the input terminal The voltage of the video output interface is compared with the standard voltage through the voltage comparison chip to judge whether a large-screen display device is connected; the output of the voltage comparison chip is connected to the portable device.

In the above-mentioned video switching device of a portable device, the external video detection unit includes an electric control switch, and the electric control switch is connected in series between the external video detection unit and the video output unit to control the external video detection unit and the video output unit The connection of the electric control switch is connected with the portable device.

In the video switching device of the portable device as described above, the video signal conversion unit includes a video signal conversion chip, the video input end of the video signal conversion chip is connected to the video output end of the portable device; the control end of the video signal conversion chip is connected to the video signal conversion chip. Portable device connected.

In the above-mentioned video switching device for portable equipment, the video output unit at least includes an impedance matching circuit and a filter circuit, and the data stream input from the video signal conversion unit passes through the impedance matching circuit and the filter circuit in sequence, and is output to the large-screen display device interface;

The video transfer device of the portable device as described above also includes an infrared receiving unit, the infrared receiving unit includes an infrared decoding chip and an infrared signal receiver; the infrared signal receiver receives the infrared signal sent by the remote controller, and converts the infrared signal into an electrical signal After sending to the infrared decoding chip, the infrared decoding chip decodes the received signal and sends it to the portable device.

Due to the disconnection or connection of the device and the external display device, the resistance of the port of the video output unit will change, thereby causing the change of the total resistance of the detection circuit, and the voltage of the detection circuit remains constant, so the voltage of the port of the video output unit will also change. There are corresponding changes. The external detection unit determines whether the external display device is connected or disconnected by comparing the port voltage of the video output unit with the standard voltage.

The video signal conversion unit is in a "sleep" state in which most of the functional units of the video signal conversion unit are closed and the clock frequency is reduced;

When the external video detection unit detects that a large-screen display device is connected, the external video detection unit sends the connection information to the portable device. The detection unit detects the external large-screen display device; then sends a "wake-up" command for power-on work to the portable device through the command interface to the video signal conversion unit, and transmits parameter setting information; the video signal conversion unit is powered on, and press the received The parameters of the parameters are set; the video signal conversion unit automatically receives the data stream from the portable device, converts it and outputs it in the specified format, and sends the converted signal to the video output unit, which is output by the video output unit after impedance matching and filtering to the large-screen display device for display. During the display process, the video signal conversion unit can also receive control commands from the portable device to complete the video control function.

When the video signal conversion unit receives the "body sleep" command from the portable device or detects that the large-screen display device is disconnected, the video signal conversion unit automatically powers off and enters the "sleep" state. At the same time, the portable device turns on the electric control switch of the external video detection unit, so that the external video detection unit enters the working state, and monitors the connection state of the external video.

The infrared receiving unit receives the information sent by the remote controller from the infrared receiving interface, converts it and sends it to the portable device, and the portable device responds to the commands sent by the remote controller; the portable device sends a command to make the video conversion unit complete power-on output or enter "Hibernate" function.

A video transfer method for a portable device, comprising the following steps:

Step 1, the external video detection unit continuously detects whether there is a large-screen display device connected; the external video detection unit detects that the large-screen display device is connected, and sends the connection information to the portable device;

Step 2: the portable device controls the video signal conversion unit to output the converted signal to the video output unit;

Step 3: After the video output unit processes the signal, it outputs it to a large-screen display device for display.

As described above in the video switching method of the portable device, the specific working process of the external detection unit in the step 1 includes:

Step 1.1 The external detection unit detects the interface voltage of the video output unit connected to the large-screen display device;

Step 1.2 is compared with the preset standard voltage through the voltage comparison chip,

Step 1.3 When the voltage of the video output interface is lower than the standard voltage, send the connection information to the portable device;

Step 1.4 When the voltage of the video output interface is greater than or equal to the standard voltage, proceed to step 1.1.

Due to the disconnection or connection of the device and the external display device, the resistance of the port of the video output unit will change, thereby causing the change of the total resistance of the detection circuit, and the voltage of the detection circuit remains constant, so the voltage of the port of the video output unit will also change. There are corresponding changes. Through this principle, the detection of an external large-screen display device is realized.

As mentioned above, the video switching method of the portable device, the step 1 further includes step 1.5 after the step 1.4: the portable device turns off the external video detection unit.

As mentioned above, the video transfer method of the portable device, the specific working process of the video signal conversion unit in the step 2 includes:

Step 2.1 The portable device sends a "wake-up" command and parameter setting information for power-on work to the video signal conversion unit;

Step 2.2 The video signal conversion unit is powered on, and the parameters are set according to the received parameters;

Step 2.3 The video signal conversion unit automatically receives the data stream from the portable device, converts it and outputs it to the video output unit in a specified format.

As described above in the video switching method for portable devices, in step 2.3 in step 2: the video signal conversion unit receives control commands from the portable device during the process of converting data streams to complete the video format conversion.

As described above, the video switching method of the portable device, the specific working process of the video output unit in the step 3 includes:

Step 3.1 The video output unit performs impedance matching on the converted video signal;

Step 3.2 The video output unit filters the impedance-matched signal;

Step 3.3 The video output unit outputs the impedance-matched and filtered signal to the connected large-screen display device for display.

As mentioned above in the video switching method of the portable device, the step 3.1 video output unit in the step 3 performs impedance matching, usually the matching impedance is 75 ohms.

As described above, the video switching method of the portable device, after the step 3, also includes the step 4, specifically as follows:

Step 4.1 When the video signal conversion unit receives the "sleep" command from the portable device, or detects that the large-screen display device is disconnected, execute step 4.2; otherwise, continue to execute step 1;

Step 4.2 The video signal conversion unit automatically powers off and enters the "sleep" state; perform step 1.

The "sleep" mentioned refers to a state in which most of the functional units (units related to video conversion: such as DAC) are turned off and the clock frequency is reduced at the same time.

As mentioned above, the video switching method of the portable device, between the steps 1 and 2, the portable device also includes turning off the external video detection unit, and after step 4, it also includes step 5: the portable device turns on the external video detection unit, so that the external video detection unit The unit enters the working state and monitors the connection state of the external video.

As mentioned above, the video switching method of the portable device, before the step 1, also includes step A: the infrared receiving unit receives the power-on command sent by the remote controller, decodes it and sends it to the portable device; after the portable device receives the signal, it automatically starts up, Output video data stream.

As mentioned above, the video transfer method for portable devices, before step 4, after step 3 also includes step B: the infrared receiving unit receives the "sleep" command sent by the remote control, decodes it and sends it to the portable device; the portable device receives After the signal, send a "sleep" bus command to the video conversion unit.

The video switching device and switching method for portable equipment proposed by the present invention realize the connection of portable equipment such as portable computers, MP3, MD and PDA with TVs, projectors and other large-screen display devices that support VGA and AV, and perform large-screen display ; It is also possible to use the same device and method to connect the portable device with various audio equipment to play sound. The invention realizes the monitoring function of the external equipment through the external video detection unit, and reduces the energy consumption to the greatest extent; and makes the control more convenient by being compatible with common remote control boards such as TVs and DVD players.

The video switching device of the portable device proposed by the present invention can be placed inside the portable device, and can also be placed outside the portable device as its plug-and-play device, which is small in size and easy to carry.

Description of drawings

Fig. 1 is a schematic block diagram of Embodiment 1 of the present invention.

Fig. 2 is a circuit diagram of an external video detection unit, video signal conversion unit and video output unit in Embodiment 1 of the present invention.

FIG. 3 is a circuit diagram of an infrared receiving unit according to Embodiment 1 of the present invention.

Fig. 4 is a flowchart of Embodiment 2 of the present invention.

Fig. 5 is a working flow diagram of the external detection unit according to the embodiment of the present invention.

Fig. 6 is a working flow diagram of the video conversion unit according to the embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be described in detail below in conjunction with the drawings and embodiments.

Embodiment 1 (device):

FIG. 1 shows a block diagram of the circuit principle of the device of this embodiment, and FIG. 2 shows a specific circuit diagram. As can be seen from Figures 1 and 2, this embodiment includes: an external video detection unit, a video signal conversion unit and a video output unit;

As shown in the upper right of Figure 2, the external video detection unit includes two S-809 voltage comparison chips, which are used to compare the voltage of the video output unit S-VIDEO and the AV port with the standard voltage, and determine the connection of the external large-screen display device. disconnect. This is because the disconnection or connection between the device and the external display device will cause the change of the port resistance of the video output unit, thereby causing the change of the total resistance of the detection circuit, and the voltage of the detection circuit remains constant, so the voltage of the port of the video output unit There will be corresponding changes.

External video detection unit VPWR_EN in the upper right block of Figure 2 is connected to the portable device. When VPWR_EN is at low level, the electronically controlled switch is closed, forming an open circuit; when VPWR_EN is at high level, the electronically controlled switch is opened to form a path. Output the connection status between the unit and the external display device. In this way, the opening and closing of the external video detection unit can be controlled.

The external video detection unit is connected to the video output unit through P_CVBS and P_C in the upper right block of Figure 2 to obtain information on whether there is an external device. The external video unit also includes an INT_V interface connected to the portable device, and sends the information to the portable device whether there is an external device. information.

As shown in the left middle of Figure 2, the video signal conversion unit selects the CH7013A chip to complete the video signal conversion. The CVBS pin and C pin of the video signal conversion chip are connected with the P_CVBS and P_C of the video output unit, and the converted data stream is sent to the video output unit. The video signal conversion unit also includes: a control command bus interface connected to the portable device, As shown in the lower left of Figure 2; used to receive various command signals from the portable device and a video signal bus interface connected to the portable device, as shown in the upper left of Figure 2, used to receive the data stream to be played from the portable device.

The video output unit includes two external device interfaces, the S-VIDEO interface and the AV (PAL) interface, namely the COMPOSITE VIDEO interface in the lower right block in Figure 2, which are used to connect the large-screen display device. In the lower right block in Figure 2, from left to right, there are impedance matching circuit, filter circuit and output interface.

When the external video detection unit detects that a large-screen display device is connected, the external video detection unit INT_V changes from a low level to a high level output. After the portable device receives this information, it first turns off the electronic control of the external video detection unit through VPWR_EN. switch, so as to close the detection function of the external video detection unit; then send the power-on command to the video signal conversion chip CH7013A through the control command bus, and transmit the parameter setting information; Parameter setting; the video signal conversion chip automatically receives the data stream from the portable device through the video signal bus, and converts the data stream according to the specified format, and sends the converted signal to the video output unit, and the video output unit undergoes impedance matching and filtering. Output to the large-screen display device for display. During the display process, the video signal conversion unit can also receive control commands from the portable device to complete the function of video format conversion.

During the working process of the video signal conversion unit, the portable device can actively issue a "sleep" command, and can also send a "sleep" command after detecting that the large-screen display device is disconnected. The portable device regularly reads the register indicating the connection status in the video conversion chip through the bus, so as to detect the connection status of the external large-screen display device. When the portable device reads the value of "no connection", it sends a "sleep" command to the video conversion unit to make it enter the dormant state.

When the video signal conversion unit receives the "sleep" command from the portable device, the video signal conversion unit automatically powers off and enters the "sleep" state. At the same time, the portable device turns on the electric control switch of the external video detection unit, so that the external video detection unit enters the working state, and monitors the connection state of the external video.

The infrared receiving unit includes an infrared decoding chip and an infrared signal receiver; the infrared signal receiver receives the infrared signal sent by the remote control, converts the infrared signal into an electrical signal and sends it to the infrared decoding chip, and the infrared decoding chip decodes the received signal and sends it to to the portable device. As shown in Figure 3, what the infrared receiving unit chooses is the IRDC370BM decoding chip. Infrared remote control board commands are introduced through the P_RXIN pin, decoded by this unit and sent to the portable device by P_IROUT and P_PWRCRL, and the portable device completes the specified function of starting up or "sleeping" according to the received command.

Embodiment 2 (method):

As shown in Figure 4, this embodiment includes the following steps:

Step A, the portable device starts up after receiving the start-up command of the infrared receiving unit, the portable device works normally, and outputs the video data stream. At this moment, the video signal conversion unit is in the "sleep" state that the video signal conversion unit is in most of the functional units (units related to video conversion: such as DAC) and the clock frequency is reduced;

Step 1 Combined with Figure 5, the external detection unit detects the voltage V1 of the video output interface and compares it with the standard voltage V0 through the voltage comparison chip. When the voltage V1 of the video output interface is greater than or equal to the standard voltage V0, the external detection unit does not do anything. Action, continue to detect the voltage V1 of the video output interface, and compare it with the standard voltage V0; when the voltage of the video output interface is lower than the standard voltage, a large-screen display device is connected at this time, and the external detection unit sends the connection status information to the portable device; portable The device turns off the external video detection unit;

Step 2 Combined with Figure 6, the portable device sends a power-on command and parameter setting information to the video signal conversion unit; the video signal conversion unit is powered on, and the parameters are set according to the received parameters; the video signal conversion unit automatically passes The video signal bus receives the data stream from the portable device, converts it according to the specified format, and then outputs it to the video output unit; during the display process, the video signal conversion unit receives the control command from the portable device through the control command bus. " command, go to step 5; if a format conversion command is received, adjust the output format of the video according to the command;

Step 3 The video output unit performs impedance matching and filtering processing on the signal, the main purpose of filtering is to reduce the impact of noise on the output video signal, and then output to the large-screen display device for display;

Step 4: The portable device receives the command from the infrared receiving unit to make the video signal conversion unit enter "sleep" and forwards it to the video signal conversion unit, and the video signal conversion unit is powered off and enters the "sleep" state;

Step 5 If the video signal conversion unit detects that the large-screen display device is disconnected, the video signal conversion unit automatically powers off and enters a "sleep" state;

Step 6: The portable device turns on the electric control switch of the external video detection unit, makes the external video detection unit enter the working state, and monitors the connection state of the external video.

Finally, it should be noted that the above embodiments are only used to illustrate and not limit the technical solutions of the present invention, although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be modified Or an equivalent replacement, any modification or partial replacement without departing from the spirit and scope of the present invention shall fall within the scope of the claims of the present invention.

Claims (17)

1. A video switching device of a portable device, characterized in that: the method comprises the following steps: the device comprises an external video detection unit, a video signal conversion unit and a video output unit; wherein,

the external video detection unit is connected with the video output unit, and the information of whether the large-screen display equipment exists or not is acquired through an output interface of the video output unit, which is used for connecting the large-screen display device; the video signal conversion unit is connected with the video output unit and sends the converted data stream to the video output unit;

the external video detection unit is provided with an interface connected to the portable equipment and used for sending information whether the large screen display device exists or not to the portable equipment;

the video signal conversion unit is provided with a control command interface and a video interface which are connected to the portable equipment; the control command interface is used for receiving various control commands from the portable equipment; the video interface is used for receiving a data stream to be converted from the portable device;

the external video detection unit at least comprises a voltage comparison chip, one input end of the voltage comparison chip is connected with an output interface of the video output unit, the other input end of the voltage comparison chip is connected with a standard voltage, the voltage comparison chip is used for comparing whether the voltage of the video output interface is smaller than the standard voltage or not, and judging whether a large-screen display device is connected or not; the output of the voltage comparison chip is connected to the portable device.

2. The video switching apparatus of portable device according to claim 1, wherein: the external video detection unit comprises an electric control switch, the electric control switch is connected in series between the external video detection unit and the video output unit and controls the connection of the external video detection unit and the video output unit, and the control end of the electric control switch is connected with the portable equipment.

3. The video switching apparatus of portable device according to claim 1, wherein: the video signal conversion unit comprises a video signal conversion chip, and a video input end of the video signal conversion chip is connected with a video output end of the portable equipment and is used for receiving a data stream to be converted; the control end of the video signal conversion chip is connected with the portable equipment and is used for receiving a control command sent by the portable equipment.

4. The video switching apparatus of portable device according to claim 1, wherein: the video output unit at least comprises an impedance matching circuit and a filter circuit, and the data stream input from the video signal conversion unit passes through the impedance matching circuit and the filter circuit in sequence and is output to the interface of the large-screen display device.

5. The video switching apparatus of portable device according to claim 4, wherein: the optimal impedance matching value of the video output unit is 75 ohms.

6. The video switching apparatus of portable device according to claim 1, wherein: the video signal output by the video output unit comprises: and two outputs of S-Video and AV.

7. The video switching apparatus of portable device according to claim 1, wherein: the infrared receiving unit comprises an infrared decoding chip and an infrared signal receiver; the infrared signal receiver receives an infrared signal sent by the remote controller, converts the infrared signal into an electric signal and sends the electric signal to the infrared decoding chip, and the infrared decoding chip decodes the received signal and sends the decoded signal to the portable equipment.

8. A video switching method of a portable device, characterized in that: video switching in any one of the devices of claims 1-7, comprising the steps of:

the method comprises the following steps that firstly, an external video detection unit continuously detects whether a large-screen display device is connected; when external video detection unit detects that there is the large screen display device to connect, send connection information to portable equipment, specific working process includes:

step 1.1, an external detection unit detects the interface voltage of a video output unit connected with a large-screen display device;

step 1.2, comparing the voltage with a preset standard voltage through a voltage comparison chip;

step 1.3, when the voltage of the video output interface is smaller than the standard voltage, sending the connection information to the portable equipment, and then executing the step two; when the voltage of the video output interface is greater than or equal to the standard voltage, continuing to execute the step 1.1;

step two, the portable equipment controls the video signal conversion unit to output the converted signal to the video output unit;

and step three, the video output unit processes the signals and outputs the signals to a large-screen display device for display.

9. The video relay method of the portable device according to claim 8, wherein: step 1.4 is also included after step 1.3 in the first step, namely the portable device turns off the external video detection unit.

10. The video relay method of the portable device according to claim 8, wherein: the specific working process of the video signal conversion unit in the second step comprises:

step 2.1, the portable device sends a power-on work 'awakening' command and parameter setting information to the video signal conversion unit;

step 2.2, powering up the video signal conversion unit, and setting parameters according to the received parameters;

and 2.3, the video signal conversion unit automatically receives the data stream from the portable equipment, converts the data stream according to a specified format and outputs the converted data stream to the video output unit.

11. The video relay method of the portable device according to claim 10, wherein: in step 2.3 in the second step, in the process of converting the data stream, the video signal conversion unit receives the control command from the portable device to complete the video format conversion.

12. The video relay method of the portable device according to claim 8, wherein: the specific working process of the video output unit in the third step comprises the following steps:

step 3.1, the video output unit performs impedance matching on the converted video signal;

step 3.2, the video output unit filters the signals after impedance matching;

and 3.3, the video output unit outputs the signals subjected to impedance matching and filtering to a connected large-screen display device for display.

13. The video relay method of the portable device according to claim 12, wherein: in the third step, the video output unit in the step 3.1 performs impedance matching, and the optimal value of the matched impedance is 75 ohms.

14. The video relay method of the portable device according to claim 8, wherein: the third step is followed by a fourth step, which is specifically as follows:

step 4.1, the video signal conversion unit receives a 'sleep' command from the portable equipment, or detects that the large screen display device is disconnected, and executes step 4.2; otherwise, continuing to execute the step one;

and 4.2, automatically powering off the video signal conversion unit, entering a dormant state, and executing the step one.

15. The video relay method of the portable device according to claim 14, wherein: and step five is included between the step one and the step two, the portable equipment closes the external video detection unit, and the portable equipment opens the external video detection unit to enable the external video detection unit to enter a working state and monitor the connection state of the external video.

16. The video relay method of the portable device according to claim 8, wherein: the first step also comprises the following steps: the infrared receiving unit receives a starting-up command sent by the remote controller, decodes the starting-up command and sends the decoded starting-up command to the portable equipment; after receiving the signal, the portable device is automatically started up and outputs a video data stream.

17. The video relay method of the portable device according to claim 14, wherein: before the fourth step, after the third step, the method also comprises a step B: the infrared receiving unit receives a 'sleep' command sent by the remote controller, decodes the command and sends the decoded command to the portable equipment; after receiving the signal, the portable device sends a 'sleep' bus command to the video conversion unit.

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