JP2004228747A - Image synchronizing apparatus and synchronization control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image synchronizing apparatus and a synchronization control apparatus capable of each synchronizing video signal generated by a plurality of image generating apparatuses having no synchronization function with each other and suppressing the occurrence of time differences in units of frames. <P>SOLUTION: The synchronization control apparatus 20 outputs a delay control variable Dn to select and read pixel data with a frame number Fmin in newest outputs of all channels whose outputs are completed and a total synchronizing signal to match timings to read the Fmin with each other to image synchronizing apparatuses 30<SB>1</SB>to 30<SB>3</SB>. The image synchronizing apparatuses 30<SB>1</SB>to 30<SB>3</SB>read pixel data with the same frame number Fmin on the basis of the delay control variable in the timing of the total synchronizing signal. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image synchronization apparatus and a synchronization control apparatus for synchronizing and displaying images generated by a plurality of image generation apparatuses on one screen.
[0002]
[Prior art]
When each video signal is generated by a plurality of image generation devices and the images based on these video signals are displayed in combination, scenes at the same time in each screen need to be simultaneously displayed on the display device.
[0003]
At this time, in the video signal format normally used in video equipment and computers, the values of the pixels constituting one image are transmitted in time series in a predetermined order. It is necessary to match the start timing.
[0004]
For example, consider a case where one screen is divided and generated by three computers, and video signals of three divided images are directly input to a projector and displayed side by side. In this case, as shown in FIG. 12, even if the composite screen G is normally displayed at time t1, if the video signals between the channels 1 to 3 are not synchronized, a time difference occurs between the channels 1 to 3, At time t2, there is a problem that the video is shifted between the divided images g1 to g3.
[0005]
On the other hand, the same applies to the case where a video composition device is interposed between each image generation device and the projector, and a plurality of video signals are synthesized and output to one projector. In this case, although the details differ depending on the synthesis method, there may be a problem that video signals at different times are synthesized, or that an image is corrupted.
[0006]
From the viewpoint of solving the above problems, an image generation apparatus (eg, a personal computer) having a synchronization function with other image generation apparatuses so as to match the start timings of the divided images generated by the image generation apparatuses. Graphic boards, etc.) are known.
[0007]
On the other hand, unlike this type of image generation apparatus, a product such as a frame synchronizer has been put to practical use as a product that realizes a synchronization function (for example, see Non-Patent Document 1).
[0008]
Such a frame synchronizer is arranged between each image generation device and a projector, temporarily stores a plurality of video signals having different start timings in a frame memory, and outputs them to one projector at a synchronized timing. is there.
[0009]
The frame synchronizer as described above is used for applications in which the start times of a plurality of video signals are matched but the output time of the video signal of a specific frame is not guaranteed. For example, a video signal of a specific frame and a video signal of a frame different from the specific frame may be displayed at the same time. For example, for the purpose of displaying video signals obtained by imaging different objects on the same screen. is there.
[0010]
[Non-Patent Document 1]
“SCAN CONVERT TRIMMING MULTI VISION BLANKING”, product catalog, Imagenics, Inc., September 2001.
[0011]
[Problems to be solved by the invention]
However, the present inventor is considering a case where video signals obtained by imaging the same object are displayed on the same screen.
That is, the present inventor is examining a technique that can synchronize the video signal and guarantees the output time of the video signal of a specific frame. Here, “guaranteeing the output time of a video signal of a specific frame” means, for example, a time difference in units of a frame such that a video signal of a certain channel is output one frame later than a video signal of another channel. It means that can be prevented.
[0012]
The present invention has been made in consideration of the above circumstances, and is an image that can synchronize each piece of video information generated by a plurality of image generation devices without a synchronization function and can prevent the occurrence of a time difference in units of frames. An object is to provide a synchronization device and a synchronization control device.
[0013]
[Means for Solving the Problems]
The invention corresponding to claim 1 is an image synchronizer for synchronizing video information transmitted from a plurality of channels of image generating devices, and includes generation timing information including time information received from the image generating devices. The image synchronization apparatus includes a calculation unit that obtains a delay control amount for eliminating a time difference between video information received from each of the image generation apparatuses.
[0014]
According to a second aspect of the present invention, there is provided an image synchronizer corresponding to the first aspect, wherein an output means for delaying and outputting each video information received from each of the image generating devices based on the delay control amount. An image synchronization apparatus provided.
[0015]
Further, the invention corresponding to claim 3 is the image synchronizer according to claim 2, wherein the output means is provided individually for each of the channels, and the video information is individually delayed and output. It is an image synchronizer provided with a plurality of information delay means.
[0016]
According to a fourth aspect of the present invention, there is provided the image synchronizer according to the second or third aspect, wherein the output means is provided individually for each channel, and pixel data based on the video information. Is an image synchronization apparatus comprising a plurality of pixel data transfer means for transferring the image data with a delay, and a combining means for combining the pixel data transferred from the pixel data transfer means.
[0017]
Furthermore, the invention corresponding to claim 5 is the image synchronizer according to any one of claims 1 to 4, wherein the calculation means includes generation timing information including time information received from each of the image generation apparatuses. Instead, the image synchronization apparatus uses the synchronization information and the frame identification information received from each of the image generation apparatuses.
[0018]
According to a sixth aspect of the present invention, in the image synchronizer corresponding to the fifth aspect, the calculation means obtains a history of frame identification information for each channel based on the synchronization information and frame identification information. And a history control means for specifying frame identification information for which output has been completed for all channels based on the history, and a delay control amount for each channel for selecting video information of the specified frame identification information And an image synchronizer comprising:
[0019]
Furthermore, the invention corresponding to claim 7 is the image synchronization apparatus according to claim 5 or 6, further comprising an output unit that uses the delay control amount obtained by the calculation unit, and the output unit includes: An image synchronization apparatus comprising: means for delaying each video information based on each synchronization information received from each image generation apparatus and the delay control amount.
[0020]
An invention corresponding to claim 8 is the image synchronization apparatus corresponding to claim 5 or claim 6, further comprising an output unit that uses the delay control amount obtained by the calculation unit, and the output unit includes: Based on each synchronization information received from each image generation device, synchronization generation means for creating output synchronization information that synchronizes when output, and each delay control amount to synchronize with the output synchronization information And a means for delaying video information.
[0021]
Further, the invention corresponding to claim 9 is an image synchronization apparatus provided for each channel and for synchronizing each video information individually transmitted from the image generation apparatus of each channel, and for each frame First-in first-out memory in which pixel data is stored, means for writing pixel data for each frame based on the video information into the first-in first-out memory, and means for reading out pixel data for each frame from the first-in first-out memory When a delay control amount is received from the outside, a read position on the first-in first-out memory is obtained from this delay control amount, and a read instruction including this read position is set based on output synchronization information set in advance or input from the outside And means for giving to the means for reading at timing.
[0022]
According to a tenth aspect of the present invention, there is provided an image synchronizer for synchronizing video information transmitted from a plurality of channels of image generating apparatuses, provided for each of the channels, and pixel data for each frame. Is stored in the first-in first-out memory of each channel, and the pixel data for each frame obtained based on the video information transmitted from the image generating apparatus of the own channel is written in the first-in first-out first memory of the own channel. Means for synthesizing the pixel data for each frame of each channel, and for each channel, reading out the pixel data for each frame from the first-in first-out memory of the channel and transferring it to the synthesis means And means for taking a history of frame identification information for each channel based on synchronization information and frame identification information received from each image generating device. Based on the history, the frame identification information that has been output in all channels is identified, a calculation means for obtaining a delay control amount in units of frames for each channel for selecting video information of the identified frame identification information, An image synchronization apparatus comprising: means for obtaining a reading position on a first-in first-out memory based on the delay control amount, and giving a transfer instruction including the reading position to the transferring means.
[0023]
Furthermore, the invention corresponding to claim 11 is a synchronization control device for synchronizing each video information transmitted from a plurality of channel image generation devices, wherein the synchronization information and frame identification information received from each image generation device Based on the above, means for taking a history of frame identification information for each channel, and identifying the frame identification information that has been output in all channels based on the history, and selecting the video information of the identified frame identification information Means for obtaining a delay control amount in units of frames for each channel, synchronization generating means for creating output synchronization information for eliminating a time difference between the synchronization information, the delay control amount and the output synchronization information And a means for outputting the video information to a destination of the video information.
[0024]
(Function)
Therefore, the invention corresponding to claim 1 is a delay control for eliminating a time difference between video information received from each image generating device based on generation timing information including time information received from each image generating device. Since the amount is obtained, it is possible to synchronize each piece of video information generated by a plurality of image generation apparatuses having no synchronization function with respect to other image generation apparatuses, and to prevent occurrence of a time difference in units of frames.
[0025]
In the invention corresponding to claim 2, since the output means delays and outputs each video information received from each image generating device based on the delay control amount, the operation corresponding to claim 1 can be easily performed. It can be played reliably.
[0026]
In the invention corresponding to claim 3, since the plurality of information delay means individually delay and output each piece of video information, the operation corresponding to claim 2 can be easily and reliably performed.
[0027]
Further, in the invention corresponding to claim 4, the plurality of pixel data transfer means delays the pixel data based on each video information and transfers it to the synthesizing means, and the synthesizing means synthesizes the transferred pixel data. Therefore, the effect | action corresponding to Claim 2, 3 can be show | played easily and reliably.
[0028]
Moreover, since the invention corresponding to claim 5 uses the synchronization information and the frame identification information instead of the generation timing information, the same action as the action corresponding to claims 1 to 4 can be achieved.
[0029]
Furthermore, the invention corresponding to claim 6 takes a history of frame identification information, and based on this history, identifies frame identification information that has been output in all channels, and obtains a delay control amount. In addition to the action corresponding to the above, it is possible to operate without trouble even when there is a missing frame.
[0030]
The invention corresponding to claim 7 delays and outputs each video information received from each image generation device based on the delay control amount obtained based on the history. Can be achieved easily and reliably.
[0031]
In the invention corresponding to claim 8, since the output synchronization information generated based on each synchronization information is used for synchronization, the operation corresponding to claims 5 and 6 can be achieved easily and reliably.
[0032]
Further, the invention corresponding to claim 9 provides the readout means for reading the pixel data to the readout means based on the delay control amount received from the outside, so that it has a simple configuration without the delay control amount calculation means. In addition, it is possible to synchronize each piece of video information generated by a plurality of image generation apparatuses that do not have a synchronization function with respect to other image generation apparatuses, and to prevent occurrence of a time difference in units of frames.
[0033]
According to a tenth aspect of the present invention, there is provided an image synchronizer corresponding to the fourth to sixth aspects and an image synchronizer corresponding to the ninth aspect on a single image synchronizer. Image synchronization actions corresponding to 4 to 6 and 9 can be obtained on one image synchronization apparatus.
[0034]
Furthermore, the invention corresponding to claim 11 obtains a delay control amount for selecting video information identified by the specified frame identification information and output synchronization information for eliminating a time difference between the synchronization information. The delay control amount and the output synchronization information are output to each video information transmission destination, so that each video information generated by a plurality of image generation devices without a synchronization function can be synchronized, and in units of frames. Generation of a time difference can be prevented.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram showing a configuration of an image display system including a synchronization control device and an image synchronization device according to the first embodiment of the present invention. This image display system includes three image generation apparatuses 10.₁-10₃One synchronization control device 20, three image synchronization devices 30₁~ 30₃And three projectors 40₁~ 40₃It has. Each device 10₁-10₃, 30₁~ 30₃, 40₁~ 40₃In addition, in the functional blocks inside thereof, the same subscripts (1 to 3) represent the same channel (signal system). Note that these three channels are merely examples, and needless to say, any number of channels can be applied as long as the number is two or more. Each device 10₁-10₃, 30₁~ 30₃, 40₁~ 40₃Is not limited to being realized as a dedicated device, but may be realized as a general-purpose computer such as a personal computer in which a program for realizing the function is read from a storage medium or a network and installed. The same applies to the following embodiments.
[0036]
Here, the image generation apparatus 10₁-10₃Generates a video signal (video information) composed of a luminance signal and a synchronization signal (synchronization information) for displaying a divided image for each frame for each channel 1, 2 and 3, and synchronizes the video signals differently. Each image synchronizer 30 at the timing₁~ 30₃Simultaneously with the output of the synchronization signal and the frame number being output to the synchronization control device 20.
[0037]
Here, the synchronization signal is an example of synchronization information. The synchronization information is information that can measure timing such as a synchronization signal such as a pulse, time information, and time information.
[0038]
The video signal is an example of video information. The video information is information such as an analog video signal or digital image data (pixel data) that can display a video.
[0039]
The outputting frame number (frame identification information) may be always output, or may be output at the start of output for each frame. The output frame number is an example of frame identification information, and may be replaced with other information as long as the information can identify the frame. Here, as the frame identification information, any identification information such as a time code used in a broadcast video device, an elapsed time, an identification name, or the like can be applied in addition to the currently output frame number. The image generation apparatus 10₁-10₃Each device 10₁-10₃It does not have a synchronization function for synchronizing video signals with each other.
[0040]
As shown in a flowchart of FIG.₁-10₃Based on the synchronization signal received from the output and the frame number being output, a function that takes a history of the frame number being output for each channel, and the latest output frame number that has been output on all channels is identified based on this history A function for obtaining a delay control amount Dn (n = 1, 2, 3) in units of frames for each channel for selecting the video signal of the specified frame number during output, and the image generation apparatus 10₁-10₃A function for creating a total synchronization signal (output synchronization information) for synchronizing each channel based on the synchronization signal received from the image, and the delay control amount Dn and the total synchronization signal are stored in the image synchronizer 30.₁~ 30₃It has a function to send to. Note that the frame unit of the delay control amount is an example, and an arbitrary unit may be used for the delay control amount instead of the frame unit.
[0041]
Here, the overall synchronization signal is an example of output synchronization information. The output synchronization information is information that can measure timing such as an overall synchronization signal such as a pulse (may be called an output synchronization signal), output time information, and output time information.
[0042]
Image synchronization device 30₁~ 30₃A / D converter 31₁~ 31₃, Write control unit 32₁~ 32₃, Image storage ring buffer 33₁~ 33₃Read controller 34₁~ 34₃, D / A converter 35₁~ 35₃And the overall control unit 36₁~ 36₃It has.
[0043]
A / D converter 31₁~ 31₃Each image generating device 10₁-10₃A / D conversion is performed on the analog luminance signal received from the digital signal, and the obtained digital pixel data is written to the write control unit 32₁~ 32₃It has a function to send to. However, the A / D converter 31₁~ 31₃Is not essential, for example, instead of an analog luminance signal, each image generating device 10₁-10₃This can be omitted when receiving a digital video signal.
[0044]
Write control unit 32₁~ 32₃The overall control unit 36₁~ 36₃On the basis of the write instruction received from the A / D converted pixel data, the image storage ring buffer 33₁~ 33₃Have the ability to write to
[0045]
Ring buffer 33 for image storage₁~ 33₃Is a first-in first-out memory in which pixel data of a plurality of frames are stored for each frame, and the write control unit 32₁~ 32₃The pixel data is written by the readout control unit 34.₁~ 34₃Thus, the pixel data is read out.
[0046]
Read control unit 34₁~ 34₃The overall control unit 36₁~ 36₃Based on the read instruction received from the image storage ring buffer 33₁~ 33₃The pixel data is read out and the D / A converter 35₁~ 35₃It has a function to send to.
[0047]
D / A converter 35₁~ 35₃Read controller 34₁~ 34₃D / A conversion is performed on the pixel data received from the projector 40, and the obtained luminance signal is converted into the projector 40.₁~ 40₃It has a function to output to. However, the D / A converter 35₁~ 35₃Is not essential. For example, an analog luminance signal is output from the projector 40.₁~ 40₃In the case of outputting a digital video signal (pixel data) to the display device instead of the case of outputting to the display device, it can be omitted.
[0048]
For example, the image synchronization device 30₁~ 30₃(Image generation device 10₁-10₃Digital image data received from a personal computer (as a projector 40)₁~ 40₃In the case of transmitting to a liquid crystal display device (provided instead of) via a DVI (digital visual interface), the A / D converter 31₁~ 31₃And D / A converter 35₁~ 35₃Is omitted.
[0049]
Overall control unit 36₁~ 36₃The image generation apparatus 10₁-10₃Based on the synchronization signal received from the image storage ring buffer 33₁~ 33₃The write control unit 32 issues a write instruction including the upper write position.₁~ 32₃The image storage ring buffer 33 is converted from the delay control amount Dn on the basis of the function provided to the synchronization control device 20 and the overall synchronization signal and delay control amount Dn received from the synchronization control device 20₁~ 33₃An upper reading position is obtained, and a reading instruction including this reading position is issued at a timing based on the overall synchronization signal.₁~ 34₃It has a function to give to.
[0050]
Here, the reading position is the ring buffer 33 for image storage.₁~ 33₃The frame position of (Dn + 1) frames ahead of the frame position during writing is obtained.
[0051]
Projector 40₁~ 40₃Each image synchronizer 30₁~ 30₃Each has a function of displaying an image on the basis of a video signal composed of an overall synchronization signal and a luminance signal. The projector 40₁~ 40₃May be changed to any type of device as long as it is a display device capable of displaying images.₁~ 40₃Instead of this, a CRT display device or a liquid crystal display device may be used.
[0052]
Next, an image synchronization method by the image synchronization apparatus configured as described above will be described with reference to the flowchart of FIG.
First, each image generating device 10₁-10₃Generates a video signal composed of a luminance signal and a synchronization signal for displaying a divided image for each frame for each of the channels 1, 2, and 3.₁~ 30₃At the same time, the synchronization signal and the output frame number are output to the synchronization controller 20.
[0053]
As shown in FIG. 3, the synchronization control device 20 includes each image generation device 10.₁-10₃To each image synchronizer 30₁~ 30₃As shown in FIG. 4, a history of the frame number Fn is held based on the synchronization signal and the frame number being output with respect to each frame of the video signal transmitted to.
[0054]
Here, the synchronization controller 20 monitors the synchronization signal for each of the channels 1 to 3 (ST1), and confirms the completion of input of one frame based on the synchronization signal for each channel n (ST2).
[0055]
When the synchronization control device 20 does not detect the synchronization signal, the synchronization control device 20 returns to step ST1 and continues monitoring (ST3: NO). The output frame number Fn and the frame number history at the time of completion are updated (ST4).
[0056]
Further, the synchronization control device 20 sets the common latest value of the input completion frame numbers of all the channels 1 to 3 as Fmin (hereinafter also referred to as the latest common frame number) (ST5).
[0057]
Thereafter, the synchronization control device 20 refers to its own memory, obtains the relative position of the frame Fn with respect to the latest common frame number Fmin on the frame number history of each channel, and determines this relative position as the delay control amount Dn ( ST6).
[0058]
For example, as shown in FIG. 4, the latest common frame number Fmin on the frame number history of each of the channels 1 to 3 is Fmin = 1. At this time, the delay control amount Dn for reading Fmin is, in the case of channel 1, the relative position difference between the currently input frame number F1 = 4 and the latest common frame number Fmin = 1 is two frames. Yes (D1 = 2). Similarly, in the case of channel 2, the relative position difference between the current “3” and the Fmin “1” is 4 frames (D2 = 4). Similarly, in the case of channel 3, the relative position difference between the current “1” and the Fmin “1” is 0 frame (D3 = 0).
[0059]
In addition, the synchronization control device 20 uses each image generation device 10 based on each synchronization signal.₁-10₃An output time difference between them is calculated, and an overall synchronization signal is generated so as to eliminate this time difference. Note that the overall synchronization signal may be a reference signal for making the output timings of the video signals coincide with each other. Therefore, the overall synchronization signal may be generated without using each synchronization signal and its output time difference.
[0060]
Subsequently, the synchronization control device 20 sends the overall synchronization signal and the delay control amount Dn to each image synchronization device 30.₁~ 30₃(ST7).
[0061]
On the other hand, each image synchronizer 30₁~ 30₃Each image generating device 10₁-10₃Among the video signals received from the A / D converter 31₁~ 31₃Is converted into digital pixel data by the write controller 32.₁~ 32₃Into.
[0062]
In addition, each image synchronization device 30₁~ 30₃Each image generating device 10₁-10₃Among the video signals received from the general control unit 36.₁~ 36₃Into.
[0063]
Overall control unit 36₁~ 36₃The image storage ring buffer 33 is based on the synchronization signal.₁~ 33₃The write control unit 32 issues a write instruction including the upper write position.₁~ 32₃To give.
[0064]
Write control unit 32₁~ 32₃In response to this write instruction, the pixel data for each frame is transferred to the image storage ring buffer 33.₁~ 33₃Write to.
[0065]
In addition, each image synchronization device 30₁~ 30₃The overall synchronization signal and the delay control amount Dn are sent to the overall control unit 36.₁~ 36₃Into.
[0066]
Overall control unit 36₁~ 36₃The image storage ring buffer 33 is calculated from the delay control amount Dn.₁~ 33₃The upper reading position is obtained, and an instruction including the reading position is read at a timing based on the entire synchronization signal.₁~ 34₃To give.
[0067]
The reading position is the image storage ring buffer 33.₁~ 33₃The frame position of (Dn + 1) frames ahead of the frame position during writing is obtained.
[0068]
Read control unit 34₁~ 34₃In response to this read instruction, the image storage ring buffer 33₁~ 33₃The pixel data of the inner frame is read and the D / A converter 35₁~ 35₃Output to.
[0069]
At this time, the read position of the output pixel data is determined by the overall control unit 36.₁~ 36₃Are synchronized with each other by the overall synchronization signal, and as shown in “current output pixel position” in FIG.₁~ 30₃Are consistent. Note that the “current transmission pixel position” in FIG.₁-10₃And image synchronizer 30₁~ 30₃The position of the pixel data corresponding to the video signal being transmitted between.
[0070]
D / A converter 35₁~ 35₃Converts the pixel data into a luminance signal to convert each projector 40₁~ 40₃Output to.
[0071]
In parallel with this, the overall control unit 36₁~ 36₃Sends the overall synchronization signal to each projector 40.₁~ 40₃Output to.
[0072]
Projector 40₁~ 40₃Displays a divided image based on a video signal composed of an overall synchronization signal and a luminance signal. Since these divided images are synchronized with each other and have no frame-by-frame error, it is possible to realize a composite image in which there is no deviation at the boundary between divided images.
[0073]
As described above, according to the present embodiment, the delay control amount Dn for selecting and reading the pixel data of the latest frame number Fmin being output that has been output in all channels is matched with the timing for reading Fmin. Are synchronized with each other by the synchronization control device 20.₁~ 30₃Output to. Each image synchronizer 30₁~ 30₃Reads out the pixel data of the same frame number Fmin based on the delay control amount Dn at the timing of the entire synchronization signal.
[0074]
Therefore, a plurality of image generation apparatuses 10 without a synchronization function.₁-10₃The video signals generated by the above can be synchronized, and the occurrence of a time difference in units of frames can be prevented.
[0075]
In the present embodiment, the case where a history is taken assuming that there is a missing frame has been described. You may deform | transform into the structure which abbreviate | omitted the function to take.
[0076]
In the case of this modification, the synchronization control device 20 includes the image generation device 10.₁-10₃A function for obtaining a delay control amount Dn in units of frames for each channel for selecting a video signal of the frame identification information based on the synchronization signal and frame identification information (for example, output frame number) received from Device 10₁-10₃A function of creating an overall synchronization signal for synchronizing the channels based on the synchronization signal received from the channel, and the delay control amount Dn and the overall synchronization signal are stored in the image synchronization device 30.₁~ 30₃It has a function to send to. Even in such a modification, the effect of the present embodiment can be obtained similarly.
[0077]
In the present embodiment, each image synchronization apparatus 30₁~ 30₃Although the case where the synchronization control device 20 is provided as a separate device has been described, the present invention is not limited to this, and as shown in FIG.₁~ 30₃Each image synchronization unit 30₁~ 30₃As shown in the figure, the image synchronizer 30 is replaced with a name representing a part of the apparatus.₁~ 30₃And the synchronization control device 20 into a single image synchronization device 30._allEven if the configuration is modified as described above, the above-described effects can be obtained in the same manner.
[0078]
Furthermore, although this embodiment described the case where the synchronous control apparatus 20 produces | generates the whole synchronization signal, the function which produces | generates the whole synchronization signal of the synchronization control apparatus 20 is abbreviate | omitted, for example, the following (1) ) And (2) may be modified.
[0079]
(1) The image synchronization device 30 receives the overall synchronization signal from another external device different from the synchronization control device 20.₁~ 30₃Configuration to enter in.
[0080]
(2) The entire synchronization signal is sent to a predetermined one image synchronization device 30._jFrom own device 30_jOverall control unit 36_jOn the other hand, each of the other image synchronization devices 30_kConfiguration to enter in.
[0081]
In the modified examples of (1) and (2), the overall synchronization signal is generated without using each synchronization signal and its output time difference, unlike the signal generated based on each synchronization signal. A reference signal for matching the output timing is used. For example, a periodic pulse signal for each frame interval can be used as the overall synchronization signal.
[0082]
(Second Embodiment)
FIG. 7 is a schematic diagram showing a configuration of an image display system including an image synchronization apparatus according to the second embodiment of the present invention. The same parts as those in FIG. Is given a subscript of x and detailed description thereof is omitted, and here, different parts will be mainly described. In the following embodiments, the same description is omitted.
[0083]
That is, this embodiment is a modification of the first embodiment, and has a preferable configuration for handling high-definition image data. Specifically, the synchronization control device 20 and the plurality of image synchronization devices 30 shown in FIG.₁~ 30₃Instead of this, one image synchronizer 50 is provided.
[0084]
Supplementally, for example, when an image is displayed by one projector, the projector 40 described above is used.₁~ 40₃When the projector 40x having a larger number of pixels than each of the above is used, the image generation processing by the image generation apparatus 10 may not be in time for the larger number of pixels. Therefore, a plurality of image generation apparatuses 10 are used for one projector 40x.₁-10₃And each image generating device 10₁-10₃Is synthesized by the image synchronizer 50 and output to the projector 40x.
[0085]
Here, specifically, the image synchronization apparatus 50 includes an overall control unit 20x and three image synchronization units 30x.₁~ 30x₃And a composite frame buffer 51.
[0086]
The overall control unit 20x includes the above-described synchronization control device 20 and the overall control unit 36.₁~ 36₃As shown in the flowchart of FIG. 8 to be described later, the image generating device 10₁-10₃Based on the synchronization signal received from the output and the frame number being output, a function that takes a history of the frame number being output for each channel, and the latest output frame number that has been output on all channels is identified based on this history A function for obtaining a delay control amount Dn (n = 1, 2, 3) in units of frames for each channel for selecting the video signal of the specified frame number during output, and the image generation apparatus 10₁-10₃A function of creating an overall synchronization signal for synchronizing the channels based on the synchronization signal received from the channel, and a ring buffer for storing images from the delay control amount Dn based on the delay control amount Dn and the overall synchronization signal. 33₁~ 33₃The upper read position is obtained, and the transfer instruction including the read position and the write position on the combined frame buffer 51 is sent at the timing based on the overall synchronization signal.₁~ 37₃And the image generating apparatus 10₁-10₃Based on the synchronization signal received from the image storage ring buffer 33₁~ 33₃The write control unit 32 issues a write instruction including the upper write position.₁~ 32₃It has a function to give to.
[0087]
Image synchronization unit 30x₁~ 30x₃Is the image synchronization device 30 described above.₁~ 30₃To the overall control unit 36₁~ 36₃Is omitted and the read control unit 34 is omitted.₁~ 34₃And D / A converter 35₁~ 35₃Instead of the composition control unit 37₁~ 37₃It is equipped with.
[0088]
Synthesis control unit 37₁~ 37₃Is stored in the image storage ring buffer 33 in accordance with the transfer instruction received from the overall control unit 20x.₁~ 33₃It has a function of reading out pixel data of a frame stored ahead of (Dn + 1) frames with respect to the frame being written, and transferring it to the composite frame buffer 51.
[0089]
The synthesis frame buffer 51 is provided with the synthesis control unit 37.₁~ 37₃Is a frame memory having a function of holding the pixel data transferred from the image data as composite image data and a function of converting the stored composite image data into a video signal by a D / A converter (not shown) and outputting the video signal to the projector 40x.
[0090]
The projector 40x is the projector 40 described above.₁~ 40₃Each of the display pixels corresponds to a larger number of display pixels than the number of display pixels, and has a function of displaying an image of a synthesis result based on a video signal received from the image synchronization device 50.
[0091]
Next, an image synchronization method by the image synchronization apparatus configured as described above will be described with reference to the flowchart of FIG.
First, in the image synchronization apparatus 50, initialization is performed by the overall control unit 20x (ST0x1 to ST3).
That is, the overall control unit 20x initializes the write frame position Wn to “1”, the input completion frame number Fn to “0”, and the delay control amount Dn to “0” for each of the channels 1, 2, and 3. (ST0x-1).
[0092]
Subsequently, the overall control unit 20x writes the write control unit 32 for each channel.₁~ 32₃The initial write frame position “1” is set (ST0x-2).
In addition, the overall control unit 20x includes a synthesis control unit 37 for each channel.₁~ 37₃The initial read frame position “0” is set (ST0x-3).
[0093]
Thereby, initialization of the image synchronizer 50 is completed. Accordingly, each image generation device 10 in the previous stage of the image synchronization device 50 is used.₁-10₃Can generate an image.
[0094]
Next, each image generation device 10₁-10₃As described above, generates a video signal for displaying a divided image for each frame for each of the channels 1, 2, and 3. However, unlike the above, where the output destination is divided for each signal, the video signal and the frame signal being output are all output to the image synchronizer 50.
[0095]
In the image synchronizer 50, the luminance signal of the video signal is converted into the A / D converter 31.₁~ 31₃Is converted into digital pixel data by the write controller 32.₁~ 32₃Into.
[0096]
Further, in the image synchronization device 50, the overall control unit 20x, as shown in FIG.₁-10₃As shown in FIG. 4, the frame number history is held on the basis of the synchronization signal and the frame number being output for each frame of the video signal transmitted from.
[0097]
Here, the overall control unit 20x executes steps ST1 to ST4 in the same manner as described above, and when a synchronization signal is detected during monitoring of the synchronization signal, the currently output frame number when the input of the channel n held in its own memory is completed. Update Fn and frame number history.
[0098]
Thereafter, the overall control unit 20x advances the write frame position Wn of the channel n by “1” frame and issues a write instruction to the write control unit 32.₁~ 32₃To send.
[0099]
As a result, the write control unit 32₁~ 32₃The image storage ring buffer 33 stores the pixel data for each frame based on the write instruction.₁~ 33₃Write to.
[0100]
Further, the overall control unit 20x sets the common latest value of the input completion frame numbers of all the channels 1 to 3 as Fmin (ST5).
[0101]
Thereafter, the overall control unit 20x refers to its own memory, obtains the relative position of the frame Fn with respect to the latest common frame number Fmin on the frame number history of each channel, and delay-controls this relative position (read frame position). A quantity Dn is determined (ST6).
[0102]
Further, the overall control unit 20x, based on each synchronization signal, each image generation device 10.₁-10₃An output time difference between them is calculated, and an overall synchronization signal is generated so as to eliminate this output time difference.
[0103]
Subsequently, the overall control unit 20x obtains the image storage ring buffer 33 obtained from the delay control amount Dn at a timing based on the overall synchronization signal.₁~ 33₃A transfer instruction including the above read position and the write position on the combined frame buffer 51 is sent to the combining control unit 37.₁~ 37₃(ST7x).
[0104]
Synthesis control unit 37₁~ 37₃In response to this transfer instruction, the image storage ring buffer 33₁~ 33₃The pixel data of the frame stored (Dn + 1) frames ahead of the frame being written in is read out and transferred to the composite frame buffer 51.
[0105]
At this time, the readout position of the pixel data to be transferred is the same as described above, because the overall control unit 20x is synchronized with each other by the overall synchronization signal. Synchronizer 30x₁~ 30x₃Are consistent. Note that the “current transmission pixel position” in FIG.₁-10₃And the position of the pixel data corresponding to the video signal being transmitted between the image synchronizer 50.
[0106]
In the composite frame buffer 51, the pixel data are combined and held as composite image data, the composite image data is converted into a video signal, and the video signal is output to each projector 40x.
[0107]
The projector 40x displays a composite result image based on the video signal. Since these synthesized images are synchronized with each other and have no frame unit error, it is possible to realize a synthesized image having no deviation at the boundary between the divided images.
[0108]
As described above, according to the present embodiment, the same effect as that of the first embodiment can be obtained even if one image synchronizer 50 combines the image data of each channel. Further, it is possible to provide the image synchronization apparatus 50 that can be applied to the high-definition projector 40x.
[0109]
In this embodiment, the case of using a synthesis memory (eg, the synthesis frame buffer 51) has been described as a synthesis method. However, the present invention is not limited to this. For example, each channel memory (eg, an image storage ring buffer) is used. 33₁~ 33₃The pixel data may be sequentially read out and synthesized, and output to an output device such as a projector without using the synthesis memory.
[0110]
(Third embodiment)
FIG. 9 is a schematic diagram showing a configuration of an image display system including an image synchronization apparatus according to the third embodiment of the present invention.
That is, this embodiment is a modification of the first embodiment, and is configured to eliminate the time difference between the video signals based on the common time information. Specifically, the three image generation apparatuses 10 are configured.₁'-10₃'Is individually connected to the three projectors 40 via the image synchronization device 60.₁~ 40₃It is the composition connected to.
[0111]
Here, the image generation apparatus 10₁'-10₃When “elapsed time information Ti is received from the image synchronizer 60, 'generates a divided image for each frame corresponding to the elapsed time information Ti for each channel 1, 2 and 3, and displays this divided image. And a generation completion signal (generation timing information) including the corresponding elapsed time information Ti are output to the image synchronizer 60. The generation completion signal is an example of generation timing information. The generation timing information is information that can measure generation timing such as a generation completion signal such as a pulse, generation time information, and generation time information.
[0112]
The image synchronization apparatus 60 includes a reference time generation unit 61, a delay control amount calculation unit 62, and three signal delay units 63.₁~ 63₃It has.
The reference time generation unit 61 sequentially generates the reference time information To and the elapsed time information Ti extracted from the reference time information To into an internal memory (not shown) for each arbitrary unit (eg, frame unit). Image generation device 10₁'-10₃'And a function of sending the reference time information To to the delay control amount calculation unit 62 in response to an acquisition request from the delay control amount calculation unit 62.
[0113]
The elapsed time information Ti is time information common to the channels 1, 2, and 3, and is a value sent from the reference time generation unit 61 for each frame or every integer multiple of each frame. The elapsed time value extracted from the reference time information To may be an absolute value of the elapsed time.
[0114]
The reference time information To is reference time information used for calculating the delay control amount Dn, and is timed with a resolution equal to or less than the period of the horizontal synchronization signal from the viewpoint of eliminating the time difference of the video signal for each channel. It is a value. Since the reference time information To and the elapsed time information Ti are calculated as differences from each other as will be described later, the same type of time or time difference (elapsed time) that is a concept that can be used as time information. Time information is used. For example, when the elapsed time information Ti is time, the reference time information To is also time. When the elapsed time information Ti is an absolute value of the elapsed time, the reference time information To is also an absolute value of the elapsed time.
[0115]
The delay control amount calculation unit 62 is connected to each image generation device 10.₁'-10₃A function for confirming detection of a generation completion signal including elapsed time information T received from ', a function for transmitting an acquisition request for reference time information To to the reference time generation unit 61 when there is detection, and an acquisition from the reference time generation unit 61 Reference time information To and each image generating device 10₁'-10₃'And the elapsed time information T in the generation completion signal received from'₁'-10₃'Determining the delay control amount Dn for eliminating the time difference between the video signals received from' and the obtained delay control amount Dn to each signal delay unit 63₁~ 63₃It has a function to send to.
[0116]
Each signal delay unit 63₁~ 63₃Are provided in parallel for each of the channels 1, 2, 3, and each image generation device 10₁'-10₃The video signals received from 'are individually delayed in parallel based on the delay control amount Dn received from the delay control amount calculation unit 62, and the projectors 40 are connected in parallel.₁~ 40₃For example, each image synchronizer 30 shown in FIG.₁~ 30₃Can be applied.
[0117]
Next, an image synchronization method by the image synchronization apparatus configured as described above will be described with reference to the flowchart of FIG.
[0118]
The reference time generation unit 61 clears a memory (not shown) in which the elapsed time information Ti is stored to zero (ST11), and subsequently generates the reference time information To sequentially.
[0119]
In addition, the reference time generation unit 61 updates the elapsed time information Ti every time the reference time information To elapses for each frame (ST12), and updates the elapsed time information Ti after the update to each image generation device 10.₁'-10₃'(ST13).
[0120]
Furthermore, the reference time generation unit 61 waits for one frame time (ST14), and returns to step ST12.
[0121]
Image generation device 10₁'-10₃′ Receives the elapsed time information Ti from the image synchronizer 60 (ST15), generates a divided image for each frame corresponding to the elapsed time information Ti for each channel 1, 2 and 3 (ST16). A video signal for displaying the divided image is transmitted to the image synchronization device 60.
[0122]
At this time, the image generation device 10₁'-10₃'Starts frame transmission following the synchronization signal in the video signal (ST17), and transmits a generation completion signal including the corresponding elapsed time information Ti to the image synchronization apparatus 60 (ST18).
[0123]
The delay control amount calculation unit 62 always confirms the detection of the generation completion signal of each channel n (= 1, 2, 3) (ST19). At this time, the delay control amount calculation unit 62 determines the presence / absence of detection (ST20), and if there is no detection, returns to step ST19 and continues the confirmation, but if there is a detection, from the reference time generation unit 21 Current reference time information To_nIs acquired (ST21).
[0124]
Subsequently, the delay control amount calculation unit 62 calculates the delay control amount Dn of the corresponding channel n based on the reference time information To and the elapsed time information Ti in the generation completion signal as follows ( ST22).
Dn = Tmax- | Ti-To_n｜
However, Tmax: Expected | Ti-To_nMaximum value of |
[0125]
For example, the delay control amount D1 for channel 1, the delay control amount D2 for channel 2, and the delay control amount D3 for channel 3 are calculated as follows:
D1 = Tmax- | Ti-To₁｜
D2 = Tmax- | Ti-To₂｜
D3 = Tmax- | Ti-To₃｜
Note that Tmax is usually equal to or longer than the time of one frame (eg, 1/30 seconds) and may be a time of 2 to 3 frames with a margin, but | Ti−To for the same calculated Ti_nIt may be the maximum value of |. However, Tmax is set to | Ti-To_nIn the case of the maximum value of |, there is a possibility that a malfunction may occur when the arrival order of the video signals between the channels is reversed, and this arrival order is known only when all the generation completion signals are received. A reception waiting time for the last generation completion signal occurs. For this reason, it is preferable to set Tmax to a fixed value.
[0126]
Also, Ti-To_nFor the term of |, the order of subtraction is reversed (To) for the convenience of not making the calculation result negative._n-Ti) may be calculated.
[0127]
In any case, the delay control amount calculation unit 62 uses the delay control amount Dn obtained in step ST22 as the signal delay unit 63 of the corresponding channel n._n(ST23). For example, the delay control amount D1 of the channel 1 is changed to the signal delay unit 63.₁The delay control amount D2 of the channel 1 is sent to the signal delay unit 63.₂The delay control amount D3 of the channel 3 is sent to the signal delay unit 63.₃To send.
[0128]
Each signal delay unit 63₁~ 63₃Each image generating device 10₁'-10₃The video signals received from 'are individually delayed in parallel based on the delay control amount Dn received from the delay control amount calculation unit 62, and the projectors 40 are connected in parallel.₁~ 40₃Output to.
[0129]
Each projector 40₁~ 40₃Displays a divided image based on each video signal as described above. Since these divided images have their time differences eliminated in advance by the respective delay control amounts Dn, it is possible to realize a composite image in which there is no deviation at the boundary between the divided images.
[0130]
As described above, according to the present embodiment, the delay control amount calculation unit 62 includes the image generation devices 10.₁'-10₃The delay control amounts D1 to D3 are calculated based on the generation completion signal including the elapsed time information Ti received from ', and the signal delay unit 63₁~ 63₃Since each video signal is delayed and output based on the delay control amounts D1 to D3, the video signals generated by a plurality of image generation devices having no synchronization function with respect to other image generation devices are synchronized. And the occurrence of a time difference in units of frames can be prevented.
[0131]
In addition, although this embodiment demonstrated the case where the elapsed time information Ti received from the reference time production | generation part 61 was used as time information contained in a generation completion signal, it is not restricted to this, Time information contained in a generation completion signal As shown in FIG.₁ ^'-10₃ ^'Even if the configuration is changed to the configuration using the elapsed time information Ti ′ at the time of image generation measured by the method, the same effect as in the present embodiment can be obtained.
[0132]
Further, in the present embodiment, the signal delay unit 63 provided in parallel is used.₁~ 63₃However, the present invention is not limited to this, and as shown in FIG.₁~ 63₃Instead of the pixel data delay unit 63₁'-63₃'And the image synchronizer 60x including the composite frame buffer 51 may be modified.
[0133]
Here, the pixel data delay unit 63₁'-63₃′ Is a signal delay unit 63.₁~ 63₃The output is pixel data instead of a video signal. For example, the signal delay unit 63₁~ 63₃The output side D / A converter (not shown) is omitted. The composite frame buffer 51 is the same as that described above in FIG.
[0134]
That is, this embodiment is modified to a configuration in which synchronization is achieved by delaying in parallel as shown in FIG. 11 instead of a configuration in which synchronization is achieved by delaying in parallel as shown in FIG. Even in this case, similar effects can be obtained.
[0135]
The method described in each of the above embodiments is a program that can be executed by a computer, such as a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), an optical disk (CD-ROM, DVD, etc.), a magneto-optical disk ( MO), and can be stored and distributed in a storage medium such as a semiconductor memory.
[0136]
Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. In addition, the embodiments may be appropriately combined as much as possible, and in that case, combined effects can be obtained. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, when an invention is extracted by omitting some constituent elements from all the constituent elements shown in the embodiment, when the extracted invention is implemented, the omitted part is appropriately supplemented by a well-known common technique. It is what is said.
[0137]
In addition, the present invention can be implemented with various modifications without departing from the gist thereof.
[0138]
【The invention's effect】
As described above, according to the present invention, it is possible to synchronize video information generated by a plurality of image generation apparatuses having no synchronization function, and to prevent occurrence of a time difference in units of frames.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of an image display system including a synchronization control device and an image synchronization device according to a first embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation in the embodiment;
FIG. 3 is a schematic diagram for explaining an operation in the embodiment;
FIG. 4 is a schematic diagram for explaining an operation in the embodiment;
FIG. 5 is a schematic diagram for explaining an operation in the embodiment;
FIG. 6 is a schematic diagram showing a modified configuration in the embodiment.
FIG. 7 is a schematic diagram showing a configuration of an image display system including an image synchronization apparatus according to a second embodiment of the present invention.
FIG. 8 is a flowchart for explaining the operation in the embodiment;
FIG. 9 is a schematic diagram showing a configuration of an image display system including an image synchronization apparatus according to a third embodiment of the present invention.
FIG. 10 is a flowchart for explaining the operation in the embodiment;
FIG. 11 is a schematic diagram showing a modified configuration in the embodiment.
FIG. 12 is a schematic diagram for explaining a conventional technique.
[Explanation of symbols]
10₁-10₃, 10₁'-10₃′… Image generation device
20 ... Synchronous control device
20x ... Overall control unit
30₁~ 30₃, 50, 60 ..Image synchronization device
30x₁~ 30x₃... Image synchronization section
31₁~ 31₃... A / D converter
32₁~ 32₃... Write controller
33₁~ 33₃... Ring buffer for image storage
34₁~ 34₃... Reading control unit
35₁~ 35₃... D / A converter
36₁~ 36₃... Overall control unit
37₁~ 37₃... Synthesis control unit
40₁~ 40₃, 40x ... Projector
51. Composite frame buffer
61 ... Reference time generator
62: Delay control amount calculation unit
63₁~ 63₃... Signal delay section
63₁'-63₃′… Pixel data delay unit

Claims (11)

An image synchronization apparatus for synchronizing video information transmitted from a multi-channel image generation apparatus,
And a calculation unit that obtains a delay control amount for eliminating a time difference between video information received from each image generation device based on generation timing information including time information received from each image generation device. Image synchronization device. The image synchronization apparatus according to claim 1,
An image synchronization apparatus comprising: output means for delaying and outputting each video information received from each image generation apparatus based on the delay control amount. The image synchronization apparatus according to claim 2, wherein
The image synchronization apparatus according to claim 1, wherein the output means includes a plurality of information delay means provided individually for each of the channels and for individually outputting the video information with a delay. In the image synchronizer according to claim 2 or 3,
The output means includes
A plurality of pixel data transfer means provided individually for each of the channels, for transferring pixel data with a delay based on the video information;
Combining means for combining the pixel data transferred from the pixel data transfer means;
An image synchronizer comprising: The image synchronization apparatus according to any one of claims 1 to 4,
The calculation means uses the synchronization information and frame identification information received from each image generation device instead of the generation timing information including time information received from each image generation device. The image synchronization apparatus according to claim 5, wherein
The calculating means includes
History means for acquiring a history of frame identification information for each channel based on the synchronization information and frame identification information;
Means for identifying frame identification information for which output has been completed in all channels based on the history, and determining a delay control amount in units of frames for each channel for selecting video information of the identified frame identification information;
An image synchronizer comprising: In the image synchronizer according to claim 5 or 6,
Output means using the delay control amount obtained by the calculating means;
The output means includes
Means for delaying each video information based on each synchronization information received from each image generation device and the delay control amount;
An image synchronizer comprising: In the image synchronizer according to claim 5 or 6,
Output means using the delay control amount obtained by the calculating means;
The output means includes
Based on each synchronization information received from each of the image generation devices, a synchronization generation means for creating output synchronization information for synchronization when outputting,
Means for delaying each video information according to the delay control amount so as to be synchronized with the output synchronization information;
An image synchronizer comprising: An image synchronization apparatus provided for each channel, for synchronizing each video information individually transmitted from the image generation apparatus of each channel,
A first-in first-out memory in which pixel data is stored for each frame;
Means for writing pixel data for each frame based on the video information into the first-in first-out memory;
Means for reading pixel data for each frame from the first-in first-out memory;
When an external delay control amount is received, a read position on the first-in first-out memory is obtained from the delay control amount, and a read instruction including the read position is set based on output synchronization information set in advance or input from the outside. Means for giving to the means for reading at
An image synchronizer comprising: An image synchronization device for synchronizing video information transmitted from a multi-channel image generation device,
A first-in first-out memory provided for each channel and storing pixel data for each frame;
Means for writing to each first-channel first-in first-out memory of pixel data provided for each channel and obtained for each frame based on video information transmitted from the image generation device of the own channel;
Combining means for combining pixel data for each frame of each channel;
Provided for each channel, means for reading out pixel data for each frame from the first-in first-out memory of the own channel and transferring the data to the combining means;
Means for taking a history of frame identification information for each channel based on synchronization information and frame identification information received from each of the image generation devices;
Calculation means for identifying frame identification information for which output has been completed for all channels based on this history, and determining a delay control amount in units of frames for each channel for selecting video information of the identified frame identification information; ,
A means for obtaining a read position on the first-in first-out memory based on the delay control amount and giving a transfer instruction including the read position to the means for transferring;
An image synchronizer comprising: A synchronization control device for synchronizing video information transmitted from a multi-channel image generation device,
Means for taking a history of frame identification information for each channel based on synchronization information and frame identification information received from each of the image generation devices;
Means for identifying frame identification information for which output has been completed in all channels based on the history, and determining a delay control amount in units of frames for each channel for selecting video information of the identified frame identification information;
Synchronization generating means for creating output synchronization information for eliminating a time difference between the respective synchronization information;
Means for outputting the delay control amount and the output synchronization information to a destination of the video information;
A synchronization control device comprising:

Images