TWI518673B - Video switch and switching method thereof - Google Patents

Description

Image switcher and switching method thereof

The present invention relates to an image switcher, and more particularly to an image switcher and a switching method thereof for shortening an image non-drawing time when an extended display identification data (EDID) of a display device is updated.

In the framework of conventional video sources, such as computers, DVD players or Blu-ray DVD players, and video output devices, such as monitors or monitors and speakers, in order to allow video sources to output audio and video output devices, support Displayed screen data. Generally speaking, the image source queries the display device's EDID via the Display Data Channel (DDC), so that the image source can know the basic parameters of the video output device, such as the manufacturer and the support screen resolution. And so on, the screen information corresponding to the video output device can be output, and the best quality of the image is displayed on the display device.

Due to the diversified needs of the display market, such as: stage performance, game broadcast or control center and any system that requires instant image switching or video wall combination, a matrix image switcher provides multiple display sources and multiple display devices in the conventional technology. Switching interface to provide solutions to different contextual needs. The so-called matrix type image switcher has a plurality of video input sources coupled to each other and a plurality of audio and video output devices. Through the switching control, multiple audio and video input sources can be output to multiple audio and video output devices, or a single audio and video input source. It is output to a plurality of video output devices, and a display effect of splitting a split screen or a video wall is generated.

In a combination of a plurality of video input sources, a matrix image switcher and a plurality of video output devices, each of the video input sources also obtains an EDID of the audio and video output device via the image switcher, and the audio and video input source is outputting audio and video. Or after the image information, if it is necessary to update the EDID, for example, when the AV output device is replaced, or in a specific case, when the EDID preset inside the image switcher is used as the video input source to output the audio or video parameters, A short picture-free situation will occur because the AV input source is to update the EDID.

Please refer to FIG. 1 to FIG. 3 , wherein FIG. 1 is a schematic diagram of a conventional image switcher architecture, and FIG. 2 to FIG. 3 are schematic diagrams of a conventional image switcher for updating an EDID. As shown in FIG. 1 , the input port of the image switcher is coupled to the image input source, and each input source corresponds to an EDID memory, such as an EEPROM, and the output of the image switcher is coupled to the audio and video output devices D1 and D2, wherein The video output devices D1 and D2 have their respective EDIDs. For example, in one case, as shown in FIG. 1 and FIG. 2, when the user wants to use the preset EDID inside the image switcher to update the EDID information stored in the original EDID memory, the control unit (Micro Control Unit) , the MCU) controls a hot plug detection (HPD) pin to be switched from a high level to a low level during which the control unit MCU writes the preset EDID to the low level. In the EDID memory, the HPD signal is then returned to the high level. When returning to the high level, the image input source reads the information newly written into the EDID memory. After a reading time, the new image is output to the video output devices D1 and D2 according to the updated EDID.

Another situation is shown in Figure 1 and Figure 3. This situation occurs when the screen is replaced. In the context of the replacement of the audio-video output device, the control unit (MCU) of the image switcher will be rooted. According to the EDID of all audio and video output devices, the optimal output picture is determined. At this time, when the user wants to change the video output device from D2 to D3, the control unit (MCU) firstly uses D1 and The EDID of D3 determines an optimal EDID, and then the control unit (MCU) controls the HPD signal on a hot plug detection pin to be switched from a high level to a low level during which the low level will be The EDID of the AV output device D3 is written into the EDID memory and then returned to the high level. When returning to the high level, the image input source reads the information newly written into the EDID memory. After a reading time, the new image is output to the video output devices D1 and D3 according to the updated EDID.

In the conventional architecture, when the above-mentioned control unit (MCU) writes the EDID to the EDID memory, the image input source interrupts the reading of the EDID memory until the control unit (MCU) completes the write operation, and then resumes. Read the EDID. While the control unit MCU writes the EDID to the EDID memory and the image input source resumes reading the EDID information in the EDID memory, the image input source cannot be normally drawn, resulting in the audio output device D1 and D2 or D1. Cannot display images with D3.

In order to shorten the time when the audio-visual display device cannot draw, there is a need for an image switcher and a switching method thereof to solve the problems caused by the conventional technology.

A main object of the present invention is to provide an image switcher that updates display information through a switching mechanism when updating display information to shorten the time of drawing.

In an embodiment, the present invention provides a video switcher, including: a control unit; and at least one display information switching module electrically connected to the control unit, each display information switching module further includes: The first storage module stores a first display information; a second storage unit; a first switching unit, wherein one of the first and second storage modules is electrically connected to the control unit; and a second switching unit is selected to be electrically connected to the first storage module The second display information is stored in the second storage module by the first switching unit, and is stored after the first display information is to be updated. Afterwards, the second switching unit switches to the second storage module to output the second display information.

In another embodiment, the present invention provides an image switching method, including the steps of: providing an image switcher with at least one image source and at least one video output device; selecting at least one video output device and one of the images The image source is coupled to the first display information stored in the image switcher to output an image signal to the image switcher according to the first display information; the image switcher outputs the image signal Providing the selected video output device; when the first display information is to be updated by the second display information, the second display information is first stored, wherein the selected image source is stored during the storing of the second display information The first display information is not interrupted; and after the second display information is stored, the image source is caused to read the second display information.

The advantages and spirit of the present invention can be further understood from the following embodiments and the accompanying drawings.

1‧‧‧Image Switcher

11‧‧‧Control unit

110‧‧‧ memory

12‧‧‧ Display information switching module

121‧‧‧First switching unit

122‧‧‧Second switching unit

123‧‧‧First storage module

124‧‧‧Second storage module

13a, 13b‧‧‧ signal processing unit

V1, V2‧‧‧ image source

D1, D2‧‧‧ audio and video output device

FIG. 1 is a schematic diagram of a matrix switching system architecture of the prior art.

2 and FIG. 3 are schematic diagrams of conventional EDID update timing.

4 is a flow chart of an embodiment of a method of the present invention.

FIG. 5 is a schematic block diagram of an embodiment of an image switcher according to the present invention.

6 is a block diagram of an embodiment of a display information switching module of the present invention.

FIG. 7 and FIG. 8 are schematic diagrams showing image signal output and interruption of different embodiments of the updated display information according to the present invention.

In the following, a plurality of embodiments of the present invention will be disclosed in the accompanying drawings. For the purpose of clarity, the details of the invention are described in the following description. However, it should be understood that these practical details are not intended to limit the invention. In addition, some of the known structures and elements are illustrated in the drawings in a simplified schematic representation.

Please refer to FIG. 4, which is a schematic diagram of an updated EDID process of the present invention. The process includes the following steps: First, step S1 is performed to provide an image switcher connected to at least one image source and at least one video output device. In this step, please refer to FIG. 5 and FIG. 6. FIG. 5 is a block diagram of an embodiment of the image switching device of the present invention, and FIG. 6 is a block diagram of an embodiment of the information switching module of the present invention. As shown in FIG. 5, the image switcher 1 has a control unit 11, a plurality of display information switching modules 12 electrically connected to the control unit 11, a plurality of input ports and output ports coupled to the control unit 11, and a plurality of signals. Processing units 13a and 13b. The input port and the output port are respectively connected to an input/output device such as a plurality of video sources V1, V2, ..., and audio/video output devices D1, D2, .... The input port and output port can be selected as one of an HDMI interface, a DVI interface, a DisplayPort interface, a Thunderbolt interface, and a VGA interface. The image source is a computer, a DVD player or a Blu-ray player that outputs images or audio and video information through an HDMI interface, a DVI interface, a DisplayPort interface, a Thunderbolt interface or a VGA interface, but is not limited thereto. The video output device D1, D2, ... can be used for LCD video, plasma TV or projector, etc. A capable display. Each of the video output devices D1, D2, ... has its own EDID.

The image switcher 1 can select an output image or a video signal in which each of the image sources V1, V2, ... is outputted to one or more of the video output devices D1, D2, . In an embodiment, the image or video information input by each of the image sources V1, V2, ... is input to the connected signal processing unit 13a via the corresponding input port. In this embodiment, the signal processing unit 13a is configured to be a video receiver, for example, an HDMI receiver or a DVI receiver for converting signals input through the input port into image information, sound information, and control information, for example, : HPD, CEC and other information. The information is switched by the switching module according to the destination video output devices D1, D2. Similarly, the destination video output devices D1, D2, . . . are also electrically connected to the signal processing unit 13b, respectively, as a video transmitter. The image information, the sound information and the control information that have been selectively switched are converted into corresponding specification signals of the audio/video output devices D1, D2, ... by the signal processing unit 13b, for example, HDMI or DVI specifications, and output to the audio/video output devices D1, D2. .

Each of the display information switching modules 12 corresponds to each of the image sources V1 and V2 for processing the EDID information to shorten the time when the image sources V1 and V2 are not drawn. As shown in FIG. 6, it is a block diagram of an embodiment of the display information switching module architecture of the present invention. In this embodiment, the display information switching module 12 is electrically connected to the control unit 11 , and includes a first switching unit 121 , a second switching unit 122 , a first storage module 123 , and a second storage module 124 . The first and second switching units 121 and 122 may be analog or digital switches. The first and second storage modules 123 and 124 are used to store the EDID, and the EDID definition stored in the first storage module 123 is defined here. For the first display information, the EDID stored in the second storage module 124 is defined as the second display information. The first switching unit 121 and the first storage module 123 and the second storage module 124 and the control list The electrical connection of the element 11 is mainly to select one of the first and second storage modules 123 or 124 to be electrically connected to the control unit 11, and the second switching unit 122 is configured to select the first or second storage module 123 or One of the 124s is electrically connected to the image source V1 to establish a transmission channel for bidirectional information. It should be noted that, in an embodiment, the foregoing transmission channel is a display data channel (DDC) for providing a communication protocol of an Inter Integrated Circuit (I2C) for bidirectional communication.

Returning to FIG. 4, a plurality of video output devices are selected to be coupled to one of the image sources as in step S2. Please refer to FIG. 5, in this step, the selection of the image source V1 is simultaneously output to the video output devices D1 and D2 for explanation. Then, as shown in FIG. 4, the selected image source in step S3 reads the first display information stored in the image switcher to output an image signal to the image switcher according to the first display information. In this step, please refer to FIG. 5 and FIG. 6 , and the display information switching module 12 corresponding to the image source V1 is used for description. It is assumed that the first display information is already stored in the first storage module 123, that is, the EDID. At this time, the second switching unit 122 switches the image source V1 to be electrically connected to the first storage module to establish a communication channel. This embodiment is a DDC channel. At this time, the image source V1 reads the first display information from the first storage module 123 through the DDC channel and the I2C communication protocol to complete step S3. Returning to FIG. 4, after step S3, proceeding to step S4, the image source V1 is drawn to the image switcher 1 according to the content of the first display information, and the image switcher 1 receives the image from the image source V1. Or the audio and video signals are output to the selected video output devices D1 and D2.

Then, when it is necessary to update the EDID information, the update is performed in the manner of steps S5 and S6. Before the steps S5 and S6 are updated, the timing of the possible update of the EDID will be described. In an embodiment, illustrated by the image switcher 1 shown in FIG. 5, the image switcher 1 is provided to the image. The source EDID information has the following modes. The first mode is the preset mode, that is, the preset value of the EDID in the image switcher. In this mode, the preset value can be used as the image source output screen. The second mode is a specific mode. In this mode, the EDID of the video output device coupled to the specific port is used as the basis for the image source drawing. In an embodiment, the specific frame is used. It can be the first one, but it is not limited to this. The other mode is an automatic mode. In this mode, the control unit 11 determines an optimized EDID according to the EDID of at least one of the audio and video output devices that need to be drawn, as a basis for the image source to draw. In the above several modes, the method of updating the EDID of the present invention can be used to shorten the time when the image source does not draw.

Therefore, when there is a need to update the EDID required for the image source to draw, that is, when the first display information is to be updated with a second display information, the second display information is first stored as shown in step S5. The selected image source does not interrupt reading the first display information during the storing of the second display information. In this step, referring to FIG. 5-7, in FIG. 7, the image output devices D1 and D2 coupled to the image switcher continuously output a picture from the image source V1, and are coupled to the image source V1 during this period. The second switching unit 122 of the display information switching module 12 is connected to the image source V1 and the first storage module 123, so that the image source V1 can read the first display information stored in the first storage module 123 through the channel. That is, the EDID outputs a picture to the video output devices D1 and D2. After the time of T0, when the user wants to use the preset EDID in the image switcher as the basis for outputting the image of the image source V1, the control unit 11 sends a control signal to control the first switching unit 121 to switch to the second. The storage module 124 is configured to electrically connect the second storage module 124 to the control unit 11. After that, the control unit 11 will store the preset EDID stored in the internal memory 110, that is, the second display information in the step S5, via the I2C communication protocol, but not limited thereto, and write to the second storage. Inside the module 124. It should be noted that the preset EDID is not stored inside the control unit. In another embodiment, the preset EDID may also be pre-stored in the storage module in the image controller, and the control unit 11 reads the module. As can be seen from FIG. 7, during the process of storing the second display information in the second storage module 124, the selected image source does not interrupt reading the first display information. That is, during the time of T1, the image source V1 can continue to read the first display information in the first storage module 123, so that the video output devices D1 and D2 can maintain the screen of continuing to output the image source V1.

Then, in step S6, after storing the second display information, the image source is caused to read the second display information. In step S6, the control unit 11 controls a hot plug signal to be switched from a high level to a low level, and during the low level, the second switching unit 122 is controlled to switch the image source V1 and the second. The storage module 124 is electrically connected to establish an information channel, such as a DDC channel. It should be noted that the Hot Plug Detection (HPD) is a detection signal in the HDMI or DVI specification, which is output through a pin in the HDMI or DVI interface of the AV output device to provide images. The source judges whether there is a screen change according to the level of the signal, so as to read the EDID information of the video output device. In general, when the HPD signal changes from a high level to a low level and then returns from a low level to a high level, the audio output device is changed. At this time, the image source reads the EDID information of the video output device. In the embodiment of the present invention, instead of directly reading the high and low levels of the HPD signal output by the video output device through the image source, the HPD is controlled by the control unit 11 in the switch to be at a high level or a low level. Changes, which in turn can control when the image source reads the EDID.

In this embodiment, the internal preset EDID is used as the image source to draw the image. Therefore, the audio output device is not actually replaced. Therefore, the HPD signal between the image source V1 and the image source V1 is actively disconnected through the control unit 11. , simulate the output of the audio and video output device, and make the shadow The image source V1 thinks that the video output device has been disconnected from it, and returns to the high level after the low level for a period of time T2, so that the image source V1 considers that the video output device has been connected, and actively reads the EDID, so that The selected image source V1 reads the second display information in the second storage module 124 via the DDC information channel. After the reading time of the T3, after the image source V1 finishes reading the second display information, the image source V1 can output the image signal to the video output devices D1 and D2 according to the read second display information. During the time of T2 and T3, the output pictures are given to the displays D1 and D2 in the image source. It can be seen from FIG. 7 that, when the EDID display information is updated, since the switching between the first and second switching units 121 and 122 and the second storage module 124 is performed, the second display information can be stored in the second storage. During the process of the module 124, the selected image source does not interrupt the reading of the first display information. Therefore, during the time of T1, the image source V1 can continue to read the first in the first storage module 123. As soon as the information is displayed, the time of drawing out of the audio-video output devices D1 and D2 is shortened to T2+T3 by the conventional non-drawing time T1+T2+T3.

Please refer to FIGS. 4-6 and FIG. 8 for explaining another embodiment of steps S5 and S6. The former embodiment is updated with a preset EDID in the switch. In this embodiment, the EDID is updated when the video output device is replaced. In this embodiment, as shown in FIG. 5 and FIG. 8 , the image source V1 provides a corresponding picture to the video output device D1 according to the first display information stored in the first storage module 123, that is, the EDID information. D2, and after a period of time T0. When the video output device D2 is replaced with D3, first, the EDID of the video output device D3 is first read by the control unit 11 to the internal memory, and the control unit 11 will update the mode according to the EDID, such as the automatic mode or the specific mode. Mode to judge. Taking the automatic mode as an example, when the EDID information of the video output device D3 is read to the memory 110 in the control unit 11, the control unit 11 determines the EDID of the video output devices D1 and D3 that are drawn according to the need. The best EDID for painting as an image source V1 Basis. After the optimal EDID is determined, the following is performed by the second display information, and step S5 is performed. The first switching unit 121 in the display information switching module 12 corresponding to the image source V1 controls the control unit 11 and the second storage. The module 124 is electrically connected, and the control unit 11 transmits the second display information to the second storage module 124 for storage via the I2C communication protocol. During the stored T1 time, the image source V1 does not interrupt the reading of the first display information by the first storage module 123, so that the video output device D1 can be continuously drawn.

After the storage is completed, proceeding to step S6, the control unit 11 controls an HPD signal to be switched from a high level to a low level to simulate a state in which the video output device is disconnected, and during the low level, the second is controlled. The switching unit 122 switches the image source V1 to be electrically connected to the second storage module 124 to establish an information channel, and then switches to the low level for a period of time T2 and then returns to the high level to simulate the audio output device being connected. The above state, the principle of controlling the HPD high level and low level is as described above, and will not be described here. Then, the selected image source V1 is caused to read the second display information in the second storage module 124 via the DDC information channel. After the T3 time, after the image source V1 finishes reading the second display information, the image source V1 can output the image signal to the video output devices D1 and D3 according to the read second display information. It can be seen from FIG. 8 that, when the EDID display information is updated, the second display information can be stored in the second storage due to the switching between the first and second switching units 121 and 122 and the second storage module 124. During the process of the module 124, that is, during the time of the T1, the image source V1 can continue to read the first display information in the first storage module 123 without being interrupted by writing the second display information. The video output device D1 can maintain the screen for continuing to output the video source V1. The non-drawing time of the video output device D1 is shortened to T2+T3 by the conventional non-drawing time T1+T2+T3. It should be noted that although the foregoing describes the update EDID mode of replacing the video output device in an automatic mode, according to the same principle, In the case where the specific 埠 mode is selected, when the audio/video output device of the specific 该 is updated, the manner in which the switcher updates the EDID is also as described above.

It should be noted that, in the foregoing embodiment of updating the EDID, the first switching unit 121 and the second switching unit 122 do not limit the mutually exclusive control conditions, and the first switching unit 121 is not synchronized with the second switching unit 122. In the reverse switching, the first switching unit 121 determines which one is electrically connected according to the control signal of the control unit 11. In another embodiment, the control of the first switching unit 121 and the second switching unit 122 may be mutually exclusive control modes, that is, when the second switching unit 122 is switched to be coupled to the second storage module 124. The first switching unit 121 is synchronously switched to be coupled to the first storage module 123. Otherwise, when the second switching unit 122 is switched to the first storage module 123, the first switching unit 121 is synchronously switched. To be coupled to the second storage module 124. Therefore, as shown in FIG. 6 , the second switching unit 122 is coupled to the first storage module 123 when the time period is T0. At this time, the first switching unit 121 and the second storage module 124 are coupled to the second storage module 124. Coupling. Therefore, the image source V1 can read the first display information stored in the first storage module 123 via the DDC channel, and output the image to the video output devices D1 and D2 according to the first display information. When the first display information is to be updated with the second display information, for example, in the case of FIG. 7-8, the control unit 11 stores the second display information in the second display information via the first switching unit 121 according to step S5. Two storage modules 124. After the time T1 is stored, the control unit 11 controls to pull the HPD signal between the image source and the image source to a low level. At this time, the control unit controls the second switching unit 122 to be coupled to the second storage module 124 at the same time, and The first switching unit 121 is coupled to the first storage module 123. After the low level has passed the time T2, the control unit 11 cuts the HPD signal between the image source V1 to the high level, and causes the image source V1 to read the second display in the second storage module 124. News. After a period of reading time T3, the image source V1 Re-draw to the audio output devices D1 and D2. Similarly, in the time when the second display information is stored in the second display module in the step S5, the image source V1 can still smoothly read the first display information stored in the first storage module 123, so During the process of entering the second display information in the second storage module 124, the image source V1 can be smoothly drawn without interruption.

According to the prior art of FIG. 1-3, the present embodiment uses the display information switching module to switch the display information in a time-sharing manner, so that the drawing time T1 can be extended to shorten the display of the display information. The video output device does not draw time.

The features and spirits of the present invention are intended to be more apparent from the detailed description of the embodiments described herein. Various changes and retouchings can be made without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

11‧‧‧Control unit

110‧‧‧ memory

12‧‧‧ Display information switching module

121‧‧‧First switching unit

122‧‧‧Second switching unit

123‧‧‧First storage module

124‧‧‧Second storage module

V1‧‧‧ image source

Claims (14)

An image switcher includes: a control unit; and at least one display information switching module electrically connected to the control unit, each display information switching module further comprises: a first storage module, storing one First display information; a second storage module; a first switching unit, selecting one of the first and second storage modules to be electrically connected to the control unit; and a second switching unit, selecting and first The storage module is electrically connected to transmit the first display information. When the first display information is to be updated, the control unit stores a second display information in the second storage mode by using the first switching unit. After the storage is completed, the second switching unit switches to the second storage module to output the second display information. The image switcher of claim 1, wherein the first and second switching units are an analog switch or a digital switch. The image switcher of claim 1, wherein the control unit converts a hot plug detection pin from a high level to a low level after the second display information is stored in the second storage module. Revert to the high level after a while. The image switcher of claim 3, wherein the second switching unit is electrically connected to the second storage module when the low level is at the low level, and provides an image source reading when returning to the high level Taking the second display information in the second storage module. The image switcher of claim 1, wherein each of the display information switching modules is further connected to an input port for receiving the first or second display information outputted by the second switching unit. The image switcher of claim 5, wherein the control unit is further coupled with a plurality of output ports, each output system selectively receiving an image information received by one of the input ports according to a switching control. The image switcher of claim 6, wherein the second display information in each of the display information switching modules is configured by the control unit to select at least one output coupled to the output port corresponding to the display information switching module.产生 is generated by replacing at least one third display information received by the video output device. The image switcher of claim 7, wherein the control unit determines an optimized display information as the second display information or the third display information of the audio/video output device coupled to the at least one output port The control unit directly uses the third display information of the replaced audio/video output device as the second display information. The image switcher of claim 1, wherein the control unit uses a preset display information as the second display information. An image switching method includes the following steps: providing an image switcher connected to at least one image source and at least one video output device; selecting at least one video output device to be coupled to one of the image sources; and selecting the selected image source to read Taking the first display information stored in the image switcher to output an image signal to the image switcher according to the first display information; the image switcher outputs the image signal to the selected video output device; When the first display information is to be updated by the second display information, the second display information is first stored, wherein the selected image source does not interrupt the reading during the storing of the second display information. After displaying the information, and storing the second display information, the image source is caused to read the second display information, wherein the second display information is a preset display information stored in the image switcher. The image switching method of claim 10, wherein the image switcher further has a first storage module and a second storage module, wherein the first storage module stores the first display information for the first And displaying the first display information in the first storage module, wherein the second storage module is configured to provide the second display information. The image switching method of claim 11, wherein the storing the second display information further comprises the steps of: controlling a hot plug signal to be converted from a high level to a low level; during the low level The selected image source is coupled to the second storage module through a switch; after the low level is cut for a period of time, the image source is restored to the high level, so that the selected image source reads the second storage The second display information in the module. An image switching method includes the following steps: providing an image switcher connected to at least one image source and at least one video output device; selecting at least one video output device to be coupled to one of the image sources; and selecting the selected image source to read Taking the first display information stored in the image switcher to output an image signal to the image switcher according to the first display information; the image switcher outputs the image signal to the selected video output device; When the first display information is to be updated by the second display information, the second display information is first stored, wherein the selected image source does not interrupt the reading during the storing of the second display information. Displaying the information; and after storing the second display information, causing the image source to read the second display information; wherein the second display information is generated by: replacing the selected video with at least one new video output device The output device determines the second display information according to the third display information of the at least one new video output device. The image switching method of claim 13, wherein the control unit determines an optimized display information as the second display information or in the third display information of the audio/video output device coupled to the at least one output port The control unit directly uses the third display information of the replaced audio/video output device as the second display information.