KR20180105430A - Multi-Display System with Network-based Auxiliary Synchronous Clock - Google Patents

Abstract

A multi-display system with a network-based synchronous auxiliary clock is provided. An image playing apparatus according to an embodiment of the present invention includes a player for playing one of images to be displayed on each of a plurality of displays, a first clock system for providing a first clock, a second clock system for providing a second clock, and a synchronization system for synchronizing an image playing time of the player with the image playing times of the other players using the first clock provided by the first clock system and the second clock provided by the second clock system. Accordingly, even if a problem occurs in a main-clock based on the network, image playing synchronization can be precisely maintained through a multi-display, a super-multi-viewpoint display, etc. using an internally generated auxiliary-clock.

Description

[0001] The present invention relates to a multi-display system having a network-based synchronous auxiliary clock,

The present invention relates to a multi-display system, and more particularly, to a multi-display system for displaying pictures in synchronization with a clock.

Recently, in the case of a multi-display used for advertisement or information display or a multi-view player display which displays a screen on multiple displays with many viewpoints, a plurality of displays The device exposes various screen display periods such as 30Hz, 60Hz, or 120Hz or the like to the screen.

At this time, each multi-display system receives and receives clock correction information from the system using the reference master clock, and each system is adjusted to the reference synchronization. Usually, the prior art synchronizes with the Precision Time Protocol (PTP) and utilizes this PTP information to provide sophisticated media playback timing.

However, when the system is used in an actual system, when the network becomes unused (idle) while the PTP is in operation, the synchronizing clock function does not work or the synchronized part is turned off in the display system.

In this case, the screens displayed between the multi-display screens are turned off, resulting in a problem in the display of the entire screen, and a search for a solution for solving the problems is requested.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide an apparatus and a method for displaying images on a plurality of displays by operating an auxiliary clock in addition to a network- There is provided a video playback apparatus capable of maintaining accurate video playback time synchronization even when a problem occurs.

According to an aspect of the present invention, there is provided an image reproducing apparatus comprising: a player for reproducing one of images to be displayed on each of a plurality of displays; A first clock system providing a first clock; A second clock system providing a second clock; And a synchronization system for synchronizing the video playback time of the player with the video playback times of the other players using a first clock provided by the first clock system and a second clock provided by the second clock system.

And, the first clock system can acquire and provide the first clock provided in the external network to the synchronization system.

Also, the second clock system can internally generate the second clock.

Then, the stability of the first clock may be higher than the stability of the second clock.

The synchronization system may also provide a first clock to the player if the first clock is provided in the first clock system.

The synchronization system may then provide a second clock to the player if the first clock is not provided in the first clock system.

The synchronization system may also provide a second clock to the player if the first clock provided by the first clock system does not match the time transition.

The synchronization system may then provide the second clock to other players.

The second clock system further includes: a receiver for receiving a first clock from the first clock system; A clock generator for generating an internal clock; An analyzer for comparing an internal clock with a first clock to correct an internal clock; And an output unit for outputting the corrected internal clock as a second clock.

According to another aspect of the present invention, there is provided an image reproducing method, including: a step of reproducing one of images to be displayed on each of a plurality of displays; And synchronizing the image reproduction time with the image reproduction times of the other reproducers using the first clock provided by the first clock system and the second clock provided by the second clock system.

According to another embodiment of the present invention, an image display system includes: a player for reproducing one of images to be displayed on each of a plurality of displays; A display for displaying an image reproduced by the player; A first clock system providing a first clock; A second clock system providing a second clock; And a synchronization system for synchronizing the video playback time of the player with the video playback times of the other players using the first clock obtained in the first clock system and the second clock generated in the second clock system.

According to another aspect of the present invention, there is provided a method of displaying an image, the method comprising: a step of reproducing one of images to be displayed on each of a plurality of displays; Displaying the reproduced image; And synchronizing the image reproduction time with the image reproduction times of the other reproducers using the first clock provided by the first clock system and the second clock provided by the second clock system.

As described above, according to the embodiments of the present invention, even when a problem occurs in a network-based main clock, even if a sub-clock generated internally is used, the video playback motive through multi display, It can be maintained precisely.

In addition, according to embodiments of the present invention, it is possible to synchronize high-definition video playback time without main clock by preparing a sub-clock near the main-clock by analyzing the network-based main-clock and correcting the sub- .

1 shows a multi-display system to which the present invention is applicable,
2 is a block diagram of an image reproducing apparatus according to an embodiment of the present invention;
FIG. 3 is a detailed block diagram of the SACS shown in FIG. 2,
4 is a diagram showing the difference in speed between the PTP clock and the internal clock.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1. Display system

1 is a diagram showing a display system to which the present invention is applicable. The illustrated display system can be implemented as a multi-display system, a super multi-display system, or the like.

Also, FIG. 1 shows the concept of time synchronization between devices via PTP. The multi-display system to which the present invention can be applied is based on IEEE 1588 PTP (Precision Time Protocol) or IEEE 802.1AS standard in an Ethernet network environment.

Point devices are all synchronized to a source that provides the same time, i.e., a Grandmaster.

For this time synchronization, each terminal must support PTP, and each terminal must be connected to the network through an Ethernet switch supporting PTP. PTP-synchronized terminals can precisely synchronize to microseconds or nanoseconds.

Therefore, the times of the used clocks of all the terminals of the network that have been synchronized with the PTP are almost exactly the same.

2. Video playback device

2 is a block diagram of an image reproducing apparatus according to an embodiment of the present invention. The image reproducing apparatus according to the embodiment of the present invention uses the network-based PTP clock as a main clock and operates the internal clock as an auxiliary clock.

More specifically, when a problem occurs in using the PTP clock which is the main-clock, the image reproducing apparatus according to the embodiment of the present invention synchronizes the image reproducing apparatus with other image reproducing apparatus using the sub- Ensure that no problems occur in synchronization.

Further, the image reproducing apparatus according to the embodiment of the present invention adjusts the auxiliary-clock using the PTP clock which is the main-clock, so that the auxiliary-clock coincides with the main-clock as much as possible.

2, the image reproducing apparatus according to the embodiment of the present invention includes a player 110, a PCS (PTP Clock System) 120, a CCS (Clock Comparator System) 130, And a Synchronization Assistant Clock System (SACS) 140.

The player 110 receives and reproduces an image, and displays the reproduced image through a display (not shown).

An image reproduced by the player 110 corresponds to one of images to be displayed on each of a plurality of displays as an image for multi-display or super-multi-view display, and a multi-screen or super multi-view image .

PCS 120 receives and acquires a PTP clock from a network switch (an Ethernet switch that supports PTP), and provides the obtained PTP clock to CCS 130 and SACS 140. The PTP clock functions as a main-clock.

The SACS 140 generates an SAC (Synchronization Assistant Clock) functioning as an auxiliary-clock using the internal clock of the system, and provides the generated SAC to the CCS 130.

The detailed structure of the SACS 140 and how the SACS 140 generates the SAC will be described later in detail.

The CCS 130 uses the PTP clock provided from the PCS 120 and the SAC provided from the SACS 140 to convert the video playback time of the player 110 into video playback times of the video playback apparatuses Synchronization system.

In order to ensure that there is no problem in image synchronization even in the event of a problem / anomalous situation, the CCS 130 performs the following functions.

1) If a PTP clock is provided from the PCS 120, the CCS 130 delivers the PTP clock to the player 110 to synchronize the video playback time with the PTP clock.

2) If the PTP clock is not provided from the PCS 120, the CCS 130 transfers the SAC provided from the SACS 140 to the player 110 to synchronize the video playback time with the SAC.

3) Even if the PTP clock is provided from the PCS 120 but the PTP clock does not conform to the time transition, the CCS 130 also transfers the SAC provided from the SACS 140 to the player 110, So that the synchronization of the video reproduction time is performed.

Whether or not it meets the time transition can be judged by comparing the PTP clock and the SAC. If the time difference is irregular as a result of the comparison, it can be determined that the PTP clock does not match the time transition.

4) When the situation of "2)" or "3)" occurs, the PCS 120 notifies the SACS 140 of the other multi- Provided SAC can be provided.

3. Synchronization Assistant Clock System (SACS)

Hereinafter, the SACS 140 will be described in detail with reference to FIG. 3 is a detailed block diagram of the SACS 140 shown in FIG. The SACS 140 includes an output unit 141, an analysis unit 142, a reception unit 143, and an internal clock generation unit 144, as shown in FIG.

The receiving unit 143 receives the PTP clock from the PCS 120 and transmits the received PTP clock to the analyzing unit 142.

The internal clock generator 144 generates an internal clock using an oscillator provided in the system, and transmits the generated internal clock to the analyzer 142.

The analysis unit 142 analyzes the PTP clock received through the reception unit 143 and corrects the internal clock generated by the internal clock generation unit 144. Unlike the PTP clock, the internal clock generated by the internal clock generator 144 is unstable and needs to be corrected.

That is, as shown in FIG. 4, the PTP clock received through the receiving unit 143 normally provides synchronization information without shaking, while in the computing environment in which various processes are executed, the internal clock generating unit 144 generates The internal clock oscillates, causing a difference in clock speed between the two.

Accordingly, the analyzer 142 grasps this difference, and continues the process of calculating and correcting? T between the PTP clock and the internal clock during the operating time of the internal clock generator 144.

The output unit 141 outputs the internal clock corrected by the analysis unit 142 to the CCS 130 as the SAC.

Up to now, a multi-display system having a network-based synchronous auxiliary clock has been described in detail with a preferred embodiment.

In an embodiment of the present invention, precise time synchronization for image reproduction / display is maintained even if the network-based PTP clock is stopped by operating an auxiliary-clock in a system for displaying images on multiple displays.

The technical idea of the present invention can be applied not only to an image reproducing apparatus that reproduces an image and transmits the image to a display, but also to an image display system that displays an image including a display.

It goes without saying that the technical idea of the present invention can also be applied to a computer-readable recording medium having a computer program for performing the functions of the apparatus and method according to the present embodiment. In addition, the technical idea according to various embodiments of the present invention may be embodied in computer-readable code form recorded on a computer-readable recording medium. The computer-readable recording medium is any data storage device that can be read by a computer and can store data. For example, the computer-readable recording medium may be a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical disk, a hard disk drive, or the like. In addition, the computer readable code or program stored in the computer readable recording medium may be transmitted through a network connected between the computers.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

110: Player 120: PCS (PTP Clock System)
130: Clock Comparator System (CCS)
140: Synchronization Assistant Clock System (SACS)
141: output section 142: analysis section
143: Receiver 144: Internal clock generator

Claims (12)

A player for reproducing one of the images to be displayed on each of the plurality of displays;
A first clock system providing a first clock;
A second clock system providing a second clock;
And a synchronization system for synchronizing the video playback time of the player with the video playback times of the other players using the first clock provided by the first clock system and the second clock provided by the second clock system, .
The method according to claim 1,
The first clock system comprises:
And acquires a first clock provided from an external network and provides the first clock to the synchronization system.
The method according to claim 1,
The second clock system,
And generates a second clock internally.
The method according to claim 1,
The stability of the first clock,
Wherein the second clock is higher than the second clock.
The method according to claim 1,
The synchronization system comprises:
Wherein when the first clock is provided in the first clock system, the first clock is provided to the player.
The method of claim 5,
The synchronization system comprises:
Wherein if the first clock is not provided in the first clock system, the second clock is provided to the player.
The method of claim 6,
The synchronization system comprises:
And provides the second clock to the player if the first clock provided by the first clock system does not match the time transition.
The method according to claim 5 or 6,
The synchronization system comprises:
And provides the second clock to the other players.
The method according to claim 1,
The second clock system,
A receiver for receiving a first clock from a first clock system;
A clock generator for generating an internal clock;
An analyzer for comparing an internal clock with a first clock to correct an internal clock; And
And outputting the corrected internal clock as a second clock.
A decimation system for reproducing one of the images to be displayed on each of the plurality of displays;
And synchronizing the image reproduction time with the image reproduction time of the other reproducers using the first clock provided by the first clock system and the second clock provided by the second clock system, Way.
A player for reproducing one of the images to be displayed on each of the plurality of displays;
A display for displaying an image reproduced by the player;
A first clock system providing a first clock;
A second clock system providing a second clock;
And a synchronization system for synchronizing the video playback time of the player with the video playback times of the other players using the first clock obtained by the first clock system and the second clock generated by the second clock system, Image display system.
A decimation system for reproducing one of the images to be displayed on each of the plurality of displays;
Displaying the reproduced image;
And synchronizing the image reproduction time with the image reproduction times of the other reproducers using the first clock provided by the first clock system and the second clock provided by the second clock system, Way.

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