JP2008197383A - Multi-display system, image display device, image display method, and image display program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-display system capable of holding consistency of images, an image display device, an image display method, and an image display program. <P>SOLUTION: The multi-display system is equipped with a plurality of image display devices 3 (3A, 3B) which display images corresponding to input image signals, and an image output device 2 which outputs the image signals to the image display devices 3 (3A, 3B). The image display devices 3 (3A, 3B) each have an image forming means 32 which is driven in predetermined display update cycles to form an image corresponding to an image signal, a time acquiring means 313 of acquiring current time, a storage means 311 of storing previously set starting point time, and a display normalizing means 315 of normalizing the display update cycles and phases of the display update cycles, and the display normalizing means times the start of the display update cycles to set time calculated from the starting point time and current time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multi-display system, an image display device, and an image display that include a plurality of image display devices that display images according to input image signals and an image output device that outputs image signals to the plurality of image display devices. The present invention relates to a method and an image display program.

  2. Description of the Related Art Conventionally, a multi-display system including a plurality of image display devices that display images according to input image signals and an image output device that outputs image signals to the plurality of image display devices is known. Examples of such an image display device include a projector that modulates a light beam emitted from a light source according to image information to form an optical image, and various displays such as liquid crystal. The image output device includes a PC (Personal Computer), a tuner that outputs an image signal based on television radio waves received via an antenna, and a player configured to be able to reproduce various disc-type recording media. Can be illustrated.

  As such a multi-display system, a tiling-type multi-projection system (see, for example, Patent Document 1) that realizes a large screen and a large number of pixels by arranging image projection areas of respective projectors as image display devices in parallel. A stacking type multi-projection system (image display system) (see, for example, Patent Document 2) that realizes high brightness and high time resolution by superimposing the image projection areas of the projectors is known.

By the way, in such a multi-projection system of the tiling method and the stacking method, it is necessary to take spatial consistency and temporal consistency in order to form and display one image by each projector. is there.
Among these, spatial consistency is to appropriately set the projection area of each projector. The temporal consistency is to appropriately set the image display timing by each projector.

In order to achieve such temporal consistency, in the multi-projection system described in Patent Document 1 described above, each projector forms and projects an image at the same timing based on a synchronization signal mixed with an input signal.
Further, in the multi-projection system described in Patent Document 2, the image information processing apparatus supplies image data (frame) having a phase shift to each projector based on the reference synchronization signal generated by the reference synchronization signal generator. Thus, the image display of each projector is shifted in time.

JP 2006-74085 A JP 2005-136868 A

However, maintaining the temporal consistency by the multi-display system as described in Patent Document 1 and Patent Document 2 described above is that each display device (projector) operates in synchronization with the input synchronization signal. However, it is difficult to realize this assumption in the following points.
First, since it is necessary to input a video signal and a synchronization signal to each display device without delay, it is necessary to dispose the display devices close to each other. However, when the projectors as display devices are arranged close to each other, the installation location becomes large, and when an obstacle that blocks the projection optical path enters, each projection image is simultaneously affected by the obstacle. is there.

  Second, the image processing performance of each display device needs to be uniform. This is because even if the input timing of the video signal is the same in each image display device, temporal consistency cannot be achieved if there is a shift in the output (display) timing. Specifically, the display device performs complex processing such as gamma correction on the input image signal, and then forms and displays an image related to the image signal. Therefore, there is a delay in image processing between the display devices. When it occurs, the display timing of the image is shifted between the display devices. For this reason, there is a problem that the consistency of the display image is lost.

Thirdly, it is necessary to align the display update cycle phase of each display device, that is, the display timing of images between the display devices. Even if the display update period (the number of display frames per second, the unit is “fps (frame per second)”) of each display device is the same, the phase of the display update period is shifted. In this case, the display timing of the image is shifted, and the consistency of the display image is lost.
The problems as described above become prominent when displaying an image related to an NTSC (National Television System Committee) standard image signal on each display device.

  That is, the NTSC standard image signal includes 29.97 frames (29.97 fps) of image information per second. On the other hand, the display update cycle of a liquid crystal panel or the like used in a display device is often 60 frames per second (60 fps). For this reason, when an NTSC standard image signal is input, a method of matching the timing of the input video signal and the image display timing by displaying the same frame image twice is known. However, in such a method, the switching cycle of the image related to each frame (that is, the cycle in which an image related to a certain input frame and an image related to another input frame input after the input frame are switched) is 30 fps. On the other hand, the frame input period of the NTSC standard image signal is as small as 29.97 fps, so that the difference (margin) between the input timing of the frame and the output (display) timing of the frame becomes shorter as time passes. On the other hand, when the difference becomes a predetermined value or less, a method of recovering the margin by displaying the same frame one more time, a total of three times, is known. However, for example, when a moving object is included in the display image, the operation of the moving object is disturbed for a moment, and the observer will recognize the rattling of the image, that is, jerkiness.

Here, the jerkiness generated in one display device is an instantaneous phenomenon, but when jerkiness occurs in each of the plurality of display devices, the shakiness of the image becomes significant.
That is, the generation timing of jerkiness is different in each display device, and when jerkiness is generated in one display device and no jerkiness occurs in other display devices, in the image display by each display device, A shift of one frame remains. As a result, the consistency of one image as a whole is lost.
The phase shift of the display update cycle that is the basis of such a phenomenon is due to individual differences among the display devices, and also occurs when the display update cycle is slightly different.

In order to avoid such a phenomenon, it is conceivable that a synchronization signal is input from the outside to match the display update cycle and phase of each display device. However, in such a case, it is necessary to wire a signal line for inputting a synchronization signal between the display devices, and it is necessary to arrange the display devices close to each other so as not to delay the input of the synchronization signal. And face the above-mentioned problems.
Due to the above problems, there has been a demand for a multi-display system capable of maintaining the consistency of display images.

  An object of the present invention is to provide a multi-display system, an image display device, an image display method, and an image display program that can maintain image consistency.

  In order to achieve the above object, a multi-display system of the present invention outputs a plurality of image display devices that display images according to input image signals, and outputs the image signals to each of the plurality of image display devices. An image output device, wherein each image display device is driven at a predetermined display update period to form an image according to the image signal, and obtains the current time A time acquisition unit, a storage unit that stores a preset start time, and a display normalization unit that normalizes the display update period and the phase of the display update period, and the display normalization unit includes the start point The start timing of the display update cycle is matched with the set time calculated from the time and the current time.

Here, normalizing the display update cycle and the phase of the display update cycle means that the display update cycle of the image forming unit and the phase of the display update cycle are made uniform among the image display devices.
The display update cycle can be the number of display frames per second (unit: “fps”).
According to the present invention, the display normalization means of each image display device is calculated based on the starting time stored in the storage means, the current time acquired by the time acquisition means, and the display update period of the image forming means. By matching the start timing of the display update cycle of the image forming unit with the set time, the display update cycle of the image forming unit included in each image display device and the phase of the display update cycle can be made uniform.

  That is, the starting time stored in each image display device is set to the same time, the display update cycle of each image forming unit is set to the same cycle, and the set time calculated from the starting time and the current time is set to a predetermined time. By matching the start timing of the display update cycle with the set time as the timing, the phase of the display update cycle of each image display device can be matched. Therefore, since the above-mentioned jerkiness generation timing can be made uniform in each image display device, the consistency of the display image by each image display device can be maintained.

  This eliminates the need for externally inputting a synchronization signal for synchronizing the phase of the display update period to each image display device, thereby eliminating the need to provide a signal line for inputting the synchronization signal. Accordingly, the configuration of the multi-display system can be simplified, and it is not necessary to input the synchronization signal to each image display device without delay. Therefore, as long as the image signal is input to each image display device without delay, each image is displayed. It is possible to eliminate the need to arrange the display devices close to each other. Therefore, the degree of freedom of arrangement of each image display device can be improved.

  In the present invention, the display normalization means includes a display difference calculation unit that calculates a difference between the current time and the starting time, and an output counter that outputs a minimum integer value equal to or greater than a value obtained by multiplying the difference by the display update period. An output counter calculating unit that calculates the output counter, an output counter adding unit that adds the starting time to a value obtained by dividing the output counter by the display update period, and a time corresponding to the value calculated by the output counter adding unit. It is preferable to include a set time calculation unit that sets the set time, and a phase setting unit that matches the start time of the display update cycle to the set time.

According to the present invention, the phase setting unit sets the start timing of the display update cycle of the image forming unit at the set time calculated by the set time calculating unit, thereby updating the display of the image forming unit in each image display device. The phase of the period can be made uniform.
That is, the output counter calculated by the output counter calculation unit is a minimum integer value equal to or greater than a value obtained by multiplying the difference between the current time and the starting time calculated by the display difference calculation unit by the display update cycle, and The set time calculated by the set time calculation unit is a time corresponding to a value obtained by dividing the output counter by the display update period. That is, the set time is the time when the start timing of the first phase after the current time when the display update cycle is considered to have started from the starting time is matched. Therefore, the phase setting unit matches the start timing of the display update cycle of the image forming unit with the set time, so that the phase of the display update cycle of the image forming unit can be made uniform in each image display device. Therefore, the consistency of the image can be reliably maintained.

In the present invention, it is preferable that each of the image display devices includes input normalization means that normalizes image information in units of frames included in the image signal in accordance with an input cycle of the image information.
Here, normalization of input image information means that image information input with a delay from the time to be input and image information input prior to the time are matched with the input period of these image information. Indicates. The input cycle can be the number of input frames per second (unit: “fps”).
According to the present invention, the input normalization means normalizes the frame unit image information included in the input image signal in accordance with the input period of the image information. Can be handled as image information input at an appropriate input cycle. Therefore, since the shift of the input timing of the image information in each image display device can be corrected, the shift of the display timing of the image information can be suppressed, and as a result, the consistency of the image can be maintained more reliably. it can.

  In the present invention, the input normalization means includes an input time acquisition unit that acquires an input time when the image information is input, an input difference calculation unit that calculates a difference between the input time and the start time, and the difference An input counter calculation unit that calculates, as an input counter, a minimum integer value that is equal to or greater than a value obtained by multiplying the input period, an input counter raising unit that adds 1 to the input counter each time the image information is input, and the input An input counter adding unit that adds the starting time to a value obtained by dividing the counter by the input period, and a virtual input time calculating unit that calculates a time corresponding to the value calculated by the input counter adding unit as a virtual input time And an association unit that associates the image information with the virtual input time.

  According to the present invention, the input counter calculation unit sets the minimum integer value that is equal to or greater than the value obtained by multiplying the difference between the input time and the start time of the image information by the input period as the input counter, Each time information is input, 1 is added to the input counter. That is, the input counter is a counter that represents the number of input image information (the number of frames) when it is considered that the input of the image information has started from the starting time. Then, the virtual input time calculation unit divides the input counter by the input period, thereby calculating the time from the start time until image information related to the input time is input, and a value obtained by adding the start time to this time The time according to is set as the virtual input time. Each time image information is input, this virtual input time is a time at which an input interval for one frame based on the input period is left, and is regarded as a virtual input time of image information input according to the input period from the start time. Can be tricked. Then, by associating the virtual input time and the image information by the associating unit, it can be considered that each image information is input without delay or preceding the input period. Therefore, it can be considered that image information related to the same frame is input at the same timing in each image display device, and thus, an image related to the frame can be displayed at the same timing. The consistency of the display image by the display device can be maintained more reliably.

  Alternatively, in the present invention, the image output device outputs the image signal including the image information and time information relating to a time according to an output cycle of the image information, and the input normalization unit includes: It is preferable that the output time be a virtual input time, and another association unit for associating with the image information related to the output time is provided.

  According to the present invention, the image signal input to each image display device includes image information in units of frames and time information related to the time according to the output cycle of the image information. The time related to the time information is associated with the image information as a virtual input time. According to this, the image information input to each image display device can be easily normalized according to the image output cycle by the image output device. Accordingly, in one of the plurality of image display devices, even when the input timing of the image information is delayed, the virtual input time of the image information can be made uniform in each image display device. Can be displayed at the same display timing, whereby the consistency of the images displayed by the respective image display devices can be reliably maintained.

  In the present invention, each of the image display devices includes an image selection unit that selects the image information normalized by the input normalization unit, and outputs the selected image information to the image forming unit. Each time an image related to the image information input to the image forming unit is displayed by the forming unit, an output counter increment that adds 1 to the output counter, and the output counter incremented by the output counter increment A starting point time adding unit that adds the value obtained by dividing the display update period to the starting point time, and an output time calculating unit that calculates a time corresponding to the value calculated by the starting point time adding unit as an output time. An image selection unit that selects the image information before the output time and the virtual input time is closest to the output time, and the image selected by the image selection unit. The information preferably comprises an image output unit that outputs to the image forming unit.

  According to the present invention, the output counter is incremented by 1 every time an image is displayed by the output counter increment, so that the number of frames (numbers) to be displayed next when the image information is considered to be sequentially input from the starting time. ), And the time corresponding to the value obtained by adding the value obtained by dividing the output counter by the display update period to the starting time is set as the output time, and the time when the image display for one frame performed immediately before has elapsed. Can be calculated. Then, the virtual input time associated with the image information is before the calculated output time and the image information closest to the output time is selected by the image selection unit and output to the image forming unit, An image related to image information to be output can be displayed at an appropriate timing without error. Therefore, each image display device can display images related to the same image information at the same timing, and thereby the consistency of the displayed images can be maintained more reliably.

In this invention, it is preferable that the said time acquisition means acquires the said present time based on the time information contained in the electromagnetic wave input from the outside.
Here, the radio wave input from the outside may be a radio wave signal including time information. For example, a long wave standard radio wave carrying time information used for a radio wave correction clock or the like can be cited, and GPS ( Examples of radio signals used in the Global Positioning System.

  According to the present invention, the time acquisition unit can acquire the same time in each image display device by acquiring radio waves including time information. According to this, when the time acquisition means of each image display device has a clock, for example, it is not necessary to set the clock. Further, when the radio wave is a standard radio wave or a GPS radio signal, the correct time can be acquired simply and accurately. Therefore, the display timing of each image by each image display device can be more reliably aligned, and the consistency of image display can be more reliably maintained.

In addition, when the image display device receives a long wave standard radio wave as the radio wave, the long wave standard radio wave can easily reach the interior of the building, so that the radio wave can be reliably received. The degree of freedom of installation can be improved.
On the other hand, when the image display device receives a GPS signal as the radio wave, the time information included in the GPS signal has an accuracy of several nanoseconds, and thus the current time is obtained more accurately. be able to.

  The image display device of the present invention is an image display device that displays an image according to input image information, and is driven at a predetermined display update period to form an image according to the image information. Means, a time acquisition means for acquiring the current time, a storage means for storing a preset starting time, and a display normalization means for normalizing the display update period and the phase of the display update period. The display normalization means matches the start timing of the display update cycle with the set time calculated from the starting time and the current time.

According to the present invention, the same effects as those of the above-described multi-display system can be achieved.
That is, the present invention is configured as a multi-display system including a plurality of image display apparatuses according to the present invention, and the start time stored in the storage means is adjusted in each image display apparatus, and then the start time and the current time acquired by the time acquisition means By aligning the start timing of the display update cycle of the image forming unit with the set time calculated from the above, the phase of the display update cycle of the image forming unit included in each image display device can be made uniform. Therefore, as described above, the consistency of the display image by each image display means can be maintained.

  In addition, the image display method of the present invention includes a plurality of image display devices that display an image according to an input image signal, and an image output device that outputs the image signal to each of the plurality of image display devices. An image display method for use in each image display device of a multi-display system to align display timing of the image by each image display device, wherein the display update cycle acquires a display update cycle of the image by the image display device An acquisition step; a current time acquisition step for acquiring a current time; a start time acquisition step for acquiring a preset start time; a display difference acquisition step for acquiring a difference between the current time and the start time; An output counter calculation step of calculating a minimum integer value equal to or greater than a value obtained by multiplying the difference by the display update period as an output counter; A set time calculating step of calculating a time according to a value obtained by adding the starting time to a value obtained by dividing the output counter by the display update cycle, and starting the display update cycle at the set time And a phase setting step for adjusting the timing.

According to the present invention, the same effects as those of the above-described multi-display system can be achieved.
In other words, by setting the smallest integer value equal to or greater than the value obtained by multiplying the difference between the current time and the starting time by the display update cycle of the image forming means as the output counter, the value of the output counter is displayed in the difference period. This is the number of frames that should have been (the number of frames in the case of advancement is +1). The time corresponding to the value obtained by adding the starting point time to the value obtained by dividing the output counter by the display update cycle is calculated in the set time calculation step as the set time that is the start timing of the display update cycle of the image forming means. The Then, in the phase setting step, the phase of the display update cycle of the image forming unit, that is, the update timing of the display update cycle is matched with the set time. By performing such a step in each image display device, the phase of the display update cycle of the image forming means can be made uniform in each image display device. Therefore, even when jerkiness occurs in each image display device, the occurrence timing of the jerkiness can be aligned, and image consistency can be maintained.

  The image display program of the present invention includes a plurality of image display devices that display an image according to an input image signal, and an image output device that outputs the image signal to each of the plurality of image display devices. An image display program executed by each image display device of a multi-display system and aligning the display timing of the image by each image display device, wherein the image display device has a display update period of the image by the image display device A display update cycle acquisition step for acquiring the current time, a current time acquisition step for acquiring the current time, a start time acquisition step for acquiring a preset start time, and a display for acquiring a difference between the current time and the start time A difference acquisition step and a minimum integer value greater than or equal to a value obtained by multiplying the difference by the display update period is calculated as an output counter. An output counter calculating step, a setting time calculating step for calculating a time corresponding to a value obtained by adding the starting time to a value obtained by dividing the output counter by the display update period, and the setting time And a phase setting step for adjusting the start timing of the display update cycle.

According to the present invention, it is possible to achieve the same effect as the above-described image display method.
That is, by executing the image display program of the present invention in each image display device, the above-described steps are processed, and the phase of the display update cycle of the image forming means provided in each image display device can be made uniform. . Therefore, the consistency of the display image can be maintained.
Such an image display program can be recorded on a recording medium such as a disk-type recording medium or a storage medium such as a semiconductor, and the image display program recorded on such a recording medium is read and executed. Thus, the same effect as the above-described image display program can be obtained. In addition, the above-described image display program can be installed and distributed using such a recording medium.

[1. First Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
[Configuration of multi-display system 1]
FIG. 1 is a diagram illustrating a configuration of a multi-display system 1 according to the present embodiment.
As shown in FIG. 1, a multi-display system (hereinafter sometimes abbreviated as MDS) 1 includes an image output device 2 such as a PC that outputs an image signal, and an image based on the image signal input from the image output device 2. Is provided with two projectors 3 (3A, 3B) as image display devices that project the image onto a projection surface such as a screen SCR. The image output device 2 and each projector 3 are connected by a LAN (Local Area Network). Each of these projectors 3 is arranged such that parts of the images projected by the respective projectors 3 are close to each other and a seam between the respective images is not recognized. That is, the MDS 1 of this embodiment is configured as a tiling type multi-projection system.

[Configuration of Projector 3]
FIG. 2 is a block diagram showing the configuration of the projector 3.
As shown in FIG. 2, the projector 3 includes a control unit 31 and an image forming unit 32 that forms and displays an image corresponding to image information input from the control unit 31.
Among these, the image forming means 32 is a light modulation device having a light source device 321 having a discharge light source lamp and a liquid crystal panel that modulates the light beam emitted from the light source device 321 in accordance with image information inputted to form image light. The apparatus 322 includes a projection optical device 323 that projects the formed image light.
The light source device 321 may use a solid light source such as an LED (Light Emitting Diode) instead of the discharge light source lamp. In addition to the liquid crystal panel, the light modulation device may include a device using a micromirror.

[Configuration of Control Unit 31]
In addition to controlling the driving of the projector 3, the control unit 31 processes an image signal input from the image output device 2 to acquire image information in units of frames and outputs the image information to the image forming unit 32. The control unit 31 includes a storage unit 311, an image signal input unit 312, a time acquisition unit 313, an input normalization unit 314, a display normalization unit 315, a display cycle generation unit 316, and an image selection unit 317.

  The storage unit 311 stores various data necessary for driving the projector 3 and various programs such as an image display program described later. The storage unit 311 also stores an input image storage unit 3111 for storing image information in units of frames input from the image output apparatus 2 and a start time used in an image display process (to be described later) processed by executing the image display program. And a starting time storage unit 3112 stored therein. In this embodiment, the starting time storage unit 3112 stores “0” indicating “January 1, 1900 0: 0: 0” as the starting time. Such a storage means can be composed of a non-volatile semiconductor memory, and can also be composed of an HDD (Hard Disk Drive) or the like.

The image signal input means 312 acquires image information in units of frames from the image signal input from the image output device 2 based on the vertical synchronization signal and the horizontal synchronization signal included in the image signal, and classifies the image information. And stored in the input image storage unit 3111. The image signal input unit 312 outputs a signal indicating to which address in the input image storage unit 3111 the image information is stored to the input normalization unit 314 each time each piece of image information is input.
The time acquisition unit 313 has a clock inside, and the current time indicated by the clock is referred to by the input normalization unit 314 and the display normalization unit 315. Note that the time of this clock has an accuracy of millisecond units and is set so as to coincide with each projector 3.

[Configuration of Input Normalization Unit 314]
FIG. 3 is a block diagram showing the configuration of the input normalization means 314.
The input normalization unit 314 normalizes the image information acquired by the image signal input unit 312. Specifically, the input normalization unit 314 calculates a virtual input time obtained by correcting the input time when each image information is input according to the input period of each image information, and associates the virtual input time with the image information. I do. As shown in FIG. 3, the input normalization means 314 includes an input period acquisition unit 3141, an input time acquisition unit 3142, an origin time acquisition unit 3143, an input difference calculation unit 3144, an input counter calculation unit 3145, and an input counter addition unit 3146. , A virtual input time calculation unit 3147, an association unit 3148, an end determination unit 3149, and an input counter raising unit 314A.

The input cycle acquisition unit 3141 acquires the input cycle of each image information based on the signal input from the image signal input unit 312.
The input time acquisition unit 3142 acquires the current time with reference to the time acquisition unit 313, and acquires the input time of the image information input to the image signal input unit 312 based on the current time.
The starting time acquisition unit 3143 acquires the starting time stored in the starting time storage unit 3112 of the storage unit 311.
The input difference calculation unit 3144 subtracts the start time acquired by the start time acquisition unit 3143 from the input time acquired by the input time acquisition unit 3142, and calculates the difference in milliseconds between the input time and the start time. calculate.

The input counter calculation unit 3145 multiplies the difference calculated by the input difference calculation unit 3144 by the input cycle of the image information acquired by the input cycle acquisition unit 3141, and the minimum integer value equal to or greater than the calculated value Is calculated. Then, the input counter calculation unit 3145 holds the calculated value as an input counter.
The input counter adding unit 3146 calculates a value obtained by adding the above-described starting time to the value (time) obtained by dividing the input counter by the above-described input cycle.

The virtual input time calculation unit 3147 calculates a time corresponding to the value calculated by the input counter addition unit 3146 as a virtual input time. In this embodiment, since “0” indicating “0 January 0, 1900, 1:00:00” is set as the starting time, the value in seconds obtained by dividing the input counter by the input period is This is the number of elapsed seconds since the starting time.
The associating unit 3148 stores the virtual input time calculated by the virtual input time calculating unit 3147 in the storage unit 311 in association with the image information related to the input time used in calculating the virtual input time.

The end determination unit 3149 determines whether the input of image information from the image output device 2 to the image signal input unit 312 has ended.
The input counter raising part 314A responds to the input of new image information when the end determination unit 3149 determines that the input of the image information has not ended, that is, the input of the image information continues. The above input counter is incremented by one. Based on the incremented input counter, a new virtual input time is calculated by the input counter adding unit 3146 and the virtual input time calculating unit 3147, and the calculated new virtual input time is updated by the associating unit 3148. Stored in association with the image information. That is, the input counter raising unit 314A increments the input counter by 1 so that the virtual input time calculated based on the input counter and the virtual input time calculated based on the input counter before the carry are increased. There is a time difference corresponding to the input period of one frame.
Thus, since the virtual input time concerning each image information is set as a time separated by an interval according to the input period, the virtual input time and the image information are stored in association with each other so that the image information The input delay is corrected.

[Configuration of Display Normalizing Unit 315]
FIG. 4 is a block diagram showing the configuration of the display normalizing means 315.
Returning to FIG. 2, the display normalizing means 315 normalizes the phase of the display update cycle by the light modulation device 322 of the image forming means 32, and aligns the image display timing in each projector 3 (3 </ b> A, 3 </ b> B). . As shown in FIG. 4, the display normalization means 315 includes a display update period acquisition unit 3151, a current time acquisition unit 3152, a start time acquisition unit 3153, a display difference calculation unit 3154, an output counter calculation unit 3155, and an output counter addition unit. 3156, a set time calculation unit 3157, and a phase setting unit 3158.

The display update cycle acquisition unit 3151 is a display update cycle (the number of frames to be displayed per second) of the light modulation device 322 generated from the drive signal of the light modulation device 322 generated by the display cycle generation means 316 described later. “Fps (frame per second)”).
The current time acquisition unit 3152 refers to the time acquisition unit 313 and acquires the current time.
The start time acquisition unit 3153 acquires the start time stored in the start time storage unit 3112.
The display difference calculation unit 3154 calculates a difference in seconds between the acquired current time and the start time.

The output counter calculation unit 3155 calculates, as an output counter, a minimum integer value that is equal to or greater than a value obtained by multiplying the difference calculated by the display difference calculation unit 3154 by the display update period. The value of this output counter is the number of frames that can be displayed during the difference period from the starting time to the current time (if the number is raised, the number of frames is +1).
The output counter addition unit 3156 adds the starting time to the value (time) in seconds obtained by dividing the calculated output counter by the display update cycle.
The set time calculation unit 3157 calculates the time corresponding to the value calculated by the output counter addition unit 3156 as the set time that becomes the start timing of the display update cycle of the light modulation device 322 (start timing of the update cycle in image display). To do.
The phase setting unit 3158 outputs a control signal to the display cycle generation unit 316 when the current time reaches the calculated set time, and notifies the display cycle generation unit 316 of the start timing of the display update cycle at the set time. Let it be set.

  Returning to FIG. 2, the display cycle generation unit 316 controls driving of the light modulation device 322 of the image forming unit 32 to control image formation of the light modulation device 322. The display cycle generation unit 316 sets the start timing of the display update cycle of the light modulation device 322 according to the control signal input from the phase setting unit 3158. Such a display cycle generation unit 316 feeds back a signal indicating the phase of the display update cycle among the drive signals output to the light modulation device 322 to the display normalization unit 315. In this embodiment, the display cycle generation unit 316 drives the light modulation device 322 at a display update cycle of 60 frames / second (60 fps).

[Configuration of Image Selection Unit 317]
FIG. 5 is a block diagram showing the configuration of the image selection means 317.
The image selection unit 317 selects and acquires image information stored in the input image storage unit 3111 and outputs the acquired image information to the light modulation device 322. At this time, the image selection unit 317 selects image information corresponding to the image update timing based on the display update period of the light modulation device 322 and outputs the image information to the light modulation device 322. As shown in FIG. 5, such an image selection unit 317 includes a display update period acquisition unit 3171, an output counter acquisition unit 3172, a start time acquisition unit 3173, an output time calculation unit 3174, an image selection unit 3175, and an image output unit 3176. , An end determination unit 3177 and an output counter raising portion 3178 are provided.

The display update period acquisition unit 3171 acquires the display update period of the light modulation device 322 described above.
The output counter acquisition unit 3172 acquires the output counter calculated by the output counter calculation unit 3155 of the display normalization unit 315.
The starting point time addition unit 3173 adds the above-described starting point time to the value obtained by dividing the acquired output counter by the display update period.
The output time calculation unit 3174 calculates the time corresponding to the value in seconds calculated by the start time addition unit 3173 as the output time. This output time is the time when the image information selected by the image selection unit 3175 is output by the image output unit 3176.

The image selection unit 3175 uses the output time calculated by the output time calculation unit 3174 from the image information stored in the input image storage unit 3111 of the storage unit 311, and the image information by the association unit 3148 of the input normalization unit 314. The image information to be output to the light modulation device 322 at the output time is selected based on the virtual input time associated with.
Specifically, the image selection unit 3175 selects image information associated with a virtual input time that is prior to the output time and that is closest to the output time. Thus, the image information can be selected in the input order according to the driving state of the light modulation device 322, and the input cycle is smaller than the display update cycle of the light modulation device 322 as in the case of the image signal of the NTSC standard described above. (In the case of an NTSC image signal, the input cycle is 29.97 fps) Even when the image signal is input, the image information output immediately before can be selected again.
The image output unit 3176 outputs the image information selected by the image selection unit 3175 to the light modulation device 322 as soon as the above output time is reached.

The end determination unit 3177 determines whether there is image information to be displayed. That is, the end determination unit 3177 determines whether there is image information that matches the image information selection condition by the image selection unit 3175.
The output counter raising unit 3178 increments the value of the output counter by one when the end determination unit 3177 determines that there is image information to be displayed.

[Image display processing]
Hereinafter, the image display process will be described.
The image display process is performed by executing the image display program stored in the storage unit 311 by the function units 312 to 317 constituting the control unit 31 of each projector 3 when displaying the image of each projector 3. This image display processing is performed by normalizing the input normalization processing SA that normalizes image information included in the image signal input from the image output device 2 and the phase of the display update period of the light modulation device 322, and then processing the image. And an image output process SB for forming and displaying.

Hereinafter, the input normalization process SA will be described.
FIG. 6 is a flowchart showing the process of the input normalization process SA constituting the image display process.
In this input normalization process SA, as shown in FIG. 6, first, the input period acquisition unit 3141 of the input normalization means 314 inputs an input period (IFR) of a frame included in an image signal input from the image output apparatus 2 ( Frame / second) is acquired (input period acquisition step SA01).
Then, the image signal input unit 312 stores the image information relating to each frame from the image signal in the input image storage unit 3111 of the storage unit 311 (input image storage step SA02).

Thereafter, the input time acquisition unit 3142 of the input normalization unit 314 acquires the input time (T _I1 ) of the image information relating to the acquired frame with reference to the time acquisition unit 313 (input time acquisition step SA03). .
Further, the start time acquisition unit 3143 acquires the start time (T ₀ ) stored in the start time storage unit 3112 of the storage unit 311 (start time acquisition step SA04).
Then, the input difference calculation unit 3144 calculates a difference (S _I = T _I1 −T ₀ ) in seconds between the acquired input time (T _I1 ) and the start time (T ₀ ) (input difference calculation step) SA05).

Next, the input counter calculation unit 3145 calculates, as the input counter (N), a minimum integer value that is equal to or greater than a value obtained by multiplying the difference (S _I ) calculated by the input difference calculation unit 3144 by the input period (IFR). (Input counter calculation step SA06).
Further, the input counter adding unit 3146 calculates a time corresponding to the value obtained by dividing the input counter (N) by the input period (IFR) (input counter division step SA07), and the virtual input time calculating unit 3147 is calculated. The time obtained by adding the starting time to the time is calculated as the virtual input time of the input image information (virtual input time calculation step SA08).
Then, the associating unit 3148 associates the calculated virtual input time with the image information related to the virtual input time and stores it in the storage unit 311 (association step SA09).

Next, the end determination unit 3149 determines whether or not the input of the image information from the image output apparatus 2 has ended (end determination step SA10).
Here, when the end determination unit 3149 determines that the input of the image information has ended, the control unit 31 ends the input normalization process SA.
On the other hand, when the end determination unit 3149 determines that the input of image information has not ended, the image signal input unit 312 stores the input image information in the input image storage unit 3111 (input image storage step). In addition to SA11), the input counter raising unit 314A increments the input counter (N) by 1 (input counter raising step SA12).
Thereafter, the control means 31 returns to step SA07, executes the steps SA07 to SA09, calculates the virtual input time based on the incremented input counter (N), and newly sets the virtual input time. The image is stored in the storage unit 311 in association with the input image information.

FIG. 7 is a chart showing image information and display timing normalized by the input normalization process SA and the image output process SB.
By executing the input normalization process SA as described above, as shown in FIG. 7, each piece of image information input from the image output apparatus 2 is normalized according to the input period of the image information. .
That is, the image information first input from the image output device 2 is an input counter (N) that is a minimum integer value equal to or greater than the value calculated from the difference between the current time and the start time when the image information is input and the input period. Is stored in association with the virtual input time based on. Then, for the image information input next to the first image information, a virtual input time obtained by adding the time required to input one frame based on the input cycle by incrementing the input counter by 314A by the input counter increment 314A. Thereafter, similarly, a virtual input time is calculated for the input image information, and the virtual input time is stored in association with the image information.

  Among these image information, for example, as indicated by a circled number 1 in FIG. 7, image information input with a delay from the input timing expected from the input cycle and as indicated by a circled number 5 The virtual input time corresponding to the expected input timing is stored in association with the image information input prior to the expected input timing. Thus, by associating the virtual input time with each image information, it can be considered that each image information is input at an input timing corresponding to the input cycle started from the starting time.

Next, the image output process SB will be described.
FIG. 8 is a flowchart showing the process of the image output process SB.
In the image output process SB, as shown in FIG. 8, first, the display update cycle acquisition unit 3151 of the display normalization unit 315 refers to the display cycle generation unit 316 to display the display update cycle (OFR) of the light modulation device 322. (Frame / second) is acquired (display update cycle acquisition step SB01).
Next, the current time acquisition unit 3152 refers to the time acquisition unit 313 and acquires the current time (T _O1 ) (current time acquisition step SB02).
Furthermore, the start time acquisition unit 3153 acquires the start time (T ₀ ) stored in the start time storage unit 3112 (start time acquisition step SB03).

Thereafter, the display difference calculation unit 3154 calculates the difference (S _O = T _O1 −T ₀ ) between the current time (T _O1 ) and the start time (T ₀ ) (display difference calculation step SB04).
Then, the output counter calculation unit 3155 calculates, as the output counter (M), a minimum integer value that is equal to or greater than the value obtained by multiplying the difference (S _O ) by the display update period (OFR) (output counter calculation step SB05).

Further, the output counter addition unit 3156 calculates a time corresponding to a value obtained by dividing the calculated output counter (M) by the display update period (OFR) (output counter division step SB06), and the starting time is determined at the calculated time. Is added to calculate a set time for setting the display update cycle start timing of the light modulation device 322 (set time calculation step SB07).
Then, the phase setting unit 3158 outputs a control signal to the display cycle generation unit 316 so that the display update timing of the light modulation device 322 is matched with the calculated set time. Then, the display cycle generation unit 316 matches the start timing of the display update cycle of the light modulation device 322 with the set time based on the control signal, so that the display update cycle of the light modulation device 322 included in each projector 3 is set. The phases can be aligned (phase setting step SB08).
Thereafter, the control means 31 executes an image selection process (SC).

FIG. 9 is a flowchart showing the process of the image selection process SC.
The image selection process SC is a process of selecting image information to be displayed based on a virtual input time associated with each image information and an output time related to the output of each image information to the light modulation device 322. .
In this image selection process SC, as shown in FIG. 9, first, the starting time addition unit 3173 of the image selection means 317 acquires the display update cycle in the output counter (M) acquired by the output counter acquisition unit 3172. Time corresponding to a value obtained by multiplying the display update period (OFR) acquired by the unit 3171 is calculated (time calculation step SC01).
And the output time calculation part 3174 calculates the output time which added the starting time to the said time (output time calculation step SC02).

Next, the image selection unit 3175 sets “having a virtual input time before the output time” and “having a virtual input time closest to the output time” as the conditions of the image information to be acquired (acquisition Condition setting step SC03).
Then, the image selection unit 3175 acquires image information associated with a virtual input time that satisfies both of the two conditions (image acquisition step SC04).
Thereafter, the image output unit 3176 outputs the image information selected by the image selection unit 3175 to the light modulation device 322 (image output step SC05).
Thus, the image selection process SC ends.

When the image selection process SC is completed, as shown in FIG. 8, an image corresponding to the image information output to the light modulation device 322 is formed by the light modulation device 322 driven at the display update period (image). Display step SB09).
Thereafter, the end determination unit 3177 of the image selection means 317 determines whether or not there is image information to be displayed next that meets the above-described selection conditions (end determination step SB10).
Here, when the end determination unit 3177 determines that the corresponding image information does not exist, that is, when it is determined that all of the input image information has been displayed, the control unit 31 ends the image output processing SB. To do.
On the other hand, if the end determination unit 3177 determines that the corresponding image information exists, the output counter raising unit 3178 increments the output counter (M) by one (output counter raising step SB11), and the control unit 31 again Then, the image selection process SC is executed.
As described above, the control unit 31 executes the image output process SB until images related to all input image information are displayed.

  By executing the image output process SB as described above, as shown in FIG. 7, a display update period is set with the set time as the start timing and the image display timing every predetermined period. Then, image information to be displayed is selected according to the output time based on the display update period, and the image information is output to the light modulation device 322, whereby an appropriate image can be displayed at an appropriate timing. .

[Operation of Projector 3]
10 and 11 are charts showing an image output state of the projector 3 when an NTSC image signal is input.
Here, the operation of the projector 3 when an NTSC image signal is input will be described.
An NTSC standard image signal (hereinafter may be abbreviated as “NTSC signal”) includes 29.97 frames of image information per second, so that when the light modulation device 322 is driven at 60 frames per second, the NTSC signal Since the input period (29.97 fps) of the image information is shorter than the display update period (60 fps in the present embodiment) of the light modulation device 322, as shown in FIG. 10, the image related to the same image information is displayed twice. Even in this case, the period (margin) until the image related to the input image information is displayed becomes shorter as time passes. In such a case, for example, when the margin is equal to or less than 1/4 (0.25 frame period) of the image display holding period for one frame, the same as shown by the circled numeral 1 in FIG. By displaying the image related to the frame three times, the margin is restored only for a period corresponding to ½ of the display holding period (0.5 frame period). At this time, the same image is added for one frame. Since the image is displayed, the above-described rattling of the image, that is, jerkiness occurs.

FIG. 12 is a chart showing jerkiness generation timing in projectors 9X and 9Y that are independently driven.
Here, in the MDS provided with the projectors 9X and 9Y that are independently driven, when the image display timing related to the display update period of the light modulation device provided in each projector 9X and 9Y is different, as shown in FIG. The jerkiness generation timing X by the projector 9X is different from the jerkiness generation timing Y by the projector 9Y. In such a case, the deviation in the generation timing of the jerkiness is not eliminated as long as the image display is continued, and thereby the consistency of the image display is lost.

FIG. 13 is a chart showing jerkiness generation timing in each projector 3A, 3B.
On the other hand, each projector 3 (3A, 3B) of the MDS 1 of the present embodiment stores the same start time in the start time storage unit 3112 of each storage means 311 and updates the display of the light modulation device 322. The period is also set the same. Each projector 3A, 3B has a start timing (set time) of the display update cycle of each projector 3A, 3B based on the current time acquired by the time acquisition means 313 in addition to the starting time and the display update cycle. Set to the same. As a result, the display update period and the phase of the display update period of the projectors 3A and 3B are aligned, so that the image display timing is aligned, and as a result, the jerkiness generation timing is generated in the projectors 3A and 3B as shown in FIG. Z will be aligned. Accordingly, jerkiness is eliminated instantly in the entire images displayed by the projectors 3A and 3B, so that the consistency of image display can be maintained.

According to the MDS 1 of the present embodiment as described above, the following effects can be obtained.
(1) The display normalizing means 315 of each projector 3 (3A, 3B) is the starting time (T ₀ ) stored in the storage means 311 and the current time (T _O1 ) acquired with reference to the time acquisition means 313. And the start timing of the display update cycle (OFR) of the light modulation device 322 is matched with the set time calculated based on the display update cycle (OFR) of the light modulation device 322. According to this, the phase of the light modulation device 322 driven at the same display update period (OFR) can be made uniform in each projector 3A, 3B. For this reason, it is possible to align the image display timings in the projectors 3A and 3B, and thus even when jerkiness occurs, the occurrence timing of the jerkiness can be aligned in the projectors 3A and 3B. Accordingly, it is possible to maintain the consistency of the display images by the projectors 3A and 3B.
In addition, since the image display timings of the projectors 3A and 3B can be aligned without inputting a synchronization signal from the outside, it is not necessary to arrange the projectors 3A and 3B close to each other. Therefore, the degree of freedom of arrangement of the projectors 3A and 3B can be improved, and wiring and the like can be simplified.

(2) The output counter (M) calculated by the output counter calculation unit 3155 in the output counter calculation step SB05 is the difference between the current time (T _O1 ) and the start time (T ₀ ) calculated by the display difference calculation unit 3154. It is the smallest integer value equal to or greater than the value obtained by multiplying the difference (S _O ) by the display update period (OFR). The set time calculated by the set time calculating unit 3157 in the set time calculating step SB07 is a time obtained by adding the starting time to the value (time) obtained by dividing the output counter (M) by the display update period (OFR). It is. According to this, it is possible to match the current image display timing with the image display timing when it is assumed that the display update cycle (OFR) has started from the start time (T ₀ ). Therefore, each projector stores the same starting time (T ₀ ), so that the phase of the display update period (OFR) of the light modulation device 322 can be made uniform. Therefore, the consistency of the image can be reliably maintained.

  (3) In the input normalization process SA, the input normalization means 314 normalizes each piece of image information in units of frames according to the input period (IFR), so that the image information is input with a delay or preceding. Even in this case, it can be handled as image information input at an appropriate input cycle. Accordingly, since the shift in the input timing of the image information in each projector 3A, 3B can be corrected, the shift in the image display timing of each projector 3A, 3B can be suppressed.

(4) The input counter calculation unit 3145 calculates a minimum integer value that is equal to or greater than a value obtained by multiplying the difference (S _I ) between the input time (T _I1 ) and start time (T ₀ ) of the image information by the input period (IFR). The input counter (N) is used, and the input counter raising unit 314A adds 1 to the input counter (N) every time image information is input. Then, the virtual input time calculation unit 3147 calculates a time corresponding to a value obtained by adding the starting time (T ₀ ) to the value (time) obtained by dividing the input counter (N) by the input cycle (IFR) as the virtual input time. To do. By associating the virtual input time and the image information by the associating unit 3148, each image information can be regarded as input at the virtual input time related to the image information. Therefore, each projector 3A, 3B can be regarded as having the same image information input at the same virtual input time, so that the image related to the image information can be displayed at the same timing, and as a result Image consistency can be maintained more reliably.

  (5) The output counter increment 3178 of the image selection means 317 increments the output counter (M) by 1 each time an image is displayed. By raising the output counter (M), the output time calculated by the output time calculation unit 3174 is set according to the image display timing in the display update cycle (OFR) from the set time. Then, the image selection unit 3175 can select an image related to the image information to be displayed without an error by selecting the image information before the output time and closest to the output time, and display the image. The image can be displayed at an appropriate image display timing in the update cycle (OFR). Therefore, the same image can be displayed at the same timing on each projector 3A, 3B.

[2. Second Embodiment]
Next, the MDS 1A according to the second embodiment of the present invention will be described. The MDS 1A has the same configuration as the MDS 1 described above. However, in each projector 3 used in the MDS 1, the time acquisition unit 313 of the control unit 31 has a configuration including a clock, whereas the MDS 1A of the present embodiment. The time acquisition means 313A of the control means 31A constituting each projector 4 used in the above is different from the MDS 1 described above in that it receives radio waves including time information indicating the current time. In the following description, parts that are the same as or substantially the same as those already described are assigned the same reference numerals and description thereof is omitted.

FIG. 14 is a block diagram showing the configuration of the MDS 1A.
The MDS 1A includes an image output device 2 and two projectors 4 (4A, 4B) that form and project an image corresponding to an image signal input from the image output device 2 on the screen SCR.
Among these, the projectors 4A and 4B have the same configuration, and as shown in FIG. 14, the projector 4 responds to a control unit 31A for controlling the entire apparatus and an image signal input from the control unit 31A. And image forming means 32 for forming an image.

Similar to the control unit 31 described above, the control unit 31A includes a storage unit 311, an image signal input unit 312, an input normalization unit 314, a display normalization unit 315, a display cycle generation unit 316, and an image selection unit 317. Instead of the time acquisition unit 313, a time acquisition unit 313A is provided.
The time acquisition unit 313A includes a clock unit 313A1 and a standard time acquisition unit 313A2. The clock unit 313A1 measures the current time. The standard time acquisition unit 313A2 receives a radio signal including time information indicating the current time from the outside, and corrects the current time measured by the clock unit 313A1 according to the time information at a predetermined timing. In the present embodiment, the standard time acquisition unit 313A2 is configured to receive a longwave standard radio wave including time information indicating the standard time, but is configured to receive a GPS (Global Positioning System) signal that also includes time information. In other words, other radio signals may be received as long as the radio wave includes time information indicating the current time.

According to the MDS 1A of the present embodiment as described above, the same effects as the MDS 1 described above can be obtained, and the following effects can be obtained.
(6) When the standard time acquisition unit 313A2 of the time acquisition unit 313A receives the long wave standard radio wave including time information, the projectors 4A and 4B can acquire the same and accurate current time. According to this, not only the time adjustment of the clock unit 313A1 of each projector 4A, 4B can be made unnecessary, but also the correct current time can be acquired, so that the image display timing of each projector 4A, 4B is further increased. It can be surely aligned.
In addition, since the standard time acquisition unit 313A2 receives the long wave standard radio wave, it is possible to simplify the configuration for acquiring such an accurate current time, and the long wave standard radio wave can easily reach the building. The degree of freedom of installation of 4 can be improved.

[3. Third Embodiment]
Hereinafter, the MDS 1B according to the third embodiment of the present invention will be described. The MDS 1B of the present embodiment has the same configuration as the MDS 1 described above. However, in the MDS1, the input time of each image information included in the image signal is calculated based on the input period and the current time of each image information, and the virtual input time and the image information are associated with each other. On the other hand, in the MDS 1B, an image signal including image information and time information indicating the time when the image information is output is output from the image output device 2B, and each projector receives the time information and the image information. Are stored in association with each other, and MDS1B is different from MDS1.

FIG. 15 is a block diagram showing the configuration of the MDS 1B.
As shown in FIG. 15, the MDS 1B includes an image output device 2B that outputs an image signal, and two projectors that project an image corresponding to the image signal input from the image output device 2B onto a projection surface such as a screen SCR. 5 (5A, 5B).
The image output device 2B includes image information generation means 2B1, time information generation means 2B2, and image signal output means 2B3.

The image information generating means 2B1 generates frame unit image information to be displayed on the projector 5.
The time information generation unit 2B2 generates time information related to the time at which the image information is output. Note that the time information generation unit 2B2 may generate time information related to the time when the image related to the image information is displayed by the projector 5. In such a case, when the current time counted by the time acquisition unit 313A included in the projector 5 described later has passed the time information related to the first image information output from the image output device 2B, Since an image is displayed, timer display is possible.

FIG. 16 is a diagram showing the contents of the image signal output by the image signal output means 2B3.
The image signal output means 2B3 generates an image signal related to image data including a header portion including time information generated by the time information generation means 2B2 and a data portion including image information generated by the image information generation means 2B1. Then, the image signal is output to each projector 5.
Specifically, the image data generated by the image signal output means 2B3 includes an IP (Internet Protocol) header, a UDP (User Datagram Protocol) header, and an RTP (Real-time Transport Protocol) header, as shown in FIG. A header portion and a data portion including the above-described image information and the like. Among these, the RTP header includes a flag, a sequence number, a time stamp, and a transmission source identifier, and the time information described above is included in the time stamp.

Returning to FIG. 15, the projector 5 (5 </ b> A, 5 </ b> B) controls the entire apparatus, processes the input image signal, and outputs image information in units of frames, and inputs from the control unit 31 </ b> B. And image forming means 32 for forming and projecting an image according to the image information.
Among these, the control unit 31B includes a storage unit 311, an image signal input unit 312, a time acquisition unit 313A, an input normalization unit 314B, a display normalization unit 315, a display cycle generation unit 316, and an image selection unit 317.

Among these, the input normalization unit 314B stores the image information included in the image signal input from the image output apparatus 2B and acquired by the image signal input unit 312 in association with the time information included in the image signal. By storing in the means 311, the image information is normalized based on the time information. The input normalization means 314B includes a time information acquisition unit 314B1, an association unit 314B2, and an end determination unit 314B3.
The time information acquisition unit 314B1 acquires time information from the RTP header included in the header portion of the input image signal.
The associating unit 314B2 corresponds to another associating unit of the present invention, and stores the time information acquired by the time information acquiring unit 314B1 in the storage unit 311 in association with the image information related to the time information.
The end determination unit 314B3 determines whether the input of image information to the image signal input unit 312 from the image output apparatus 2B has ended.

Hereinafter, the input normalization process SD executed by the projector 5 of the present embodiment will be described.
When the projector 5 forms and projects an image according to the image signal input from the image output device 2B, the projector 5 executes an image display process including the input normalization process SD and the image output process SB. Among these, the input normalization process SD is a process for storing the time information included in the input image signal in association with the image information related to the time information.
This image display processing is performed by the control means 31B executing the image display program stored in the storage means 311.

FIG. 17 is a flowchart showing the process of the input normalization process SD.
In this input normalization process SD, as shown in FIG. 17, first, the image signal input unit 312 acquires image information in units of frames from the input image signal, and the image information is stored in the input image storage unit of the storage unit 311. 3111 (input image storage step SD01).
At this time, the time information acquisition unit 314B1 of the input normalization means 314B acquires time information related to the image information (time information acquisition step SD02), and the associating unit 314B2 uses the time information as a virtual input time to obtain image information. Is stored in the storage unit 311 (association step SD03).

Thereafter, the end determination unit 314B3 determines whether or not the input of the image information has ended, and if the end determination unit 314B3 determines that the image information input has not ended, the control unit 31B Returning to step SD01, the input image information is stored and the time information related to the image information is associated.
If the end determination unit 314B3 determines that the image information input has ended, the control unit 31B ends the input normalization process SD.
On the other hand, in the control means 31B, the image output processing SB is executed, the image display is normalized by the light modulation device 322, and based on the virtual input time and the output time of the image information to the light modulation device 322, Selection and output of image information relating to the displayed image is performed.

According to the MDS 1B of the present embodiment as described above, the effects (1), (2), (5), (6) that can be achieved by the above-described MDS can be achieved, and the following effects can be achieved. Can do.
(7) The image output device 2B that outputs an image signal to each projector 5 (5A, 5B) outputs an image signal including image information and time information related to the time when the image information was output. This time information is based on the image output period of the image output device 2B, and is the time related to the time information related to certain image information and the time related to the time information corresponding to the image information output next to the image information. And there is a time difference according to the output period for one frame. Then, the input normalization means 314B of each projector 5A, 5B acquires the time information, and the associating unit 314B2 stores the time indicated by the acquired time information as a virtual input time in association with the input image information. .
According to this, not only can the virtual input time corresponding to each image information be easily acquired, but also the association between the image information and the virtual input time can be easily performed. Further, since the output source of the time information related to the virtual input time is one place of the image output device 2B, the virtual input times corresponding to the respective image information can be surely aligned in each projector 5A, 5B. Therefore, it is possible to reliably maintain the consistency of images by the projectors 5A and 5B.

[4. Modification of Embodiment]
The present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.
In each of the above embodiments, the minimum integer value equal to or greater than the value obtained by multiplying the difference between the current time and the start time by the display update cycle is used as an output counter, and the start time is added to the value obtained by dividing the output counter by the display update cycle. Although the time according to the value is set as the start time of the display update cycle, the present invention is not limited to this. That is, each projector may drive the light modulation device at a display update period with the start time as the start timing.

In each of the above embodiments, the multi-display systems 1, 1A, 1B are each configured to include two projectors 3, 4, 5, but the present invention is not limited to this. That is, the number of projectors may be set as appropriate as long as it is two or more.
In the above embodiments, the multi-display systems 1, 1A, 1B are configured as a tiling-type multi-projection system in which the projection areas of the images by the projectors 3, 4, 5 are arranged in parallel. You may comprise as a stacking type multi-projection system.

  In each of the above embodiments, the image output device 2 is configured by a PC or the like. However, the present invention is not limited to this, and may be configured by various image output devices capable of outputting an image signal. For example, examples of such an image output device include a player that can reproduce a disc-type recording medium such as a DVD (Digital Versatile Disc), a tuner that receives and outputs a television image signal, and the like.

  In the above embodiments, the multi-display systems 1, 1A, 1B are configured to include the projectors 3, 4, 5 as image display devices, but the present invention is not limited to this. For example, the image display device may be configured by a display such as liquid crystal, plasma, organic EL, and CRT. Further, the projector is not limited to the front type that projects from the direction in which the screen SCR is observed, but may be a rear type projector that projects from the side opposite to the direction in which the screen SCR is observed.

1 is a diagram showing a configuration of a multi-display system according to a first embodiment of the present invention. The block diagram which shows the structure of the multi-display system in the said embodiment. The block diagram which shows the structure of the input normalization means in the said embodiment. The block diagram which shows the structure of the display normalization means in the said embodiment. The block diagram which shows the structure of the image selection means in the said embodiment. The flowchart which shows the process of the input normalization process in the said embodiment. The chart which shows the normalized image information and display timing in the said embodiment. 3 is a flowchart showing a process of image output processing in the embodiment. 5 is a flowchart showing a process of image selection processing in the embodiment. The chart which shows the image output state when the NTSC signal in the said embodiment is input. The chart which shows the image output state when the NTSC signal in the said embodiment is input. 6 is a chart showing jerkiness generation timing of each projector in a conventional multi-projection system. 6 is a chart showing jerkiness occurrence timing of each projector in the embodiment. The block diagram which shows the structure of the multi-display system which concerns on 2nd Embodiment of this invention. The block diagram which shows the structure of the multi-display system which concerns on 3rd Embodiment of this invention. The figure which shows the content of the image signal which the image signal output means in the said embodiment outputs. The flowchart which shows the process of the input normalization process in the said embodiment.

Explanation of symbols

  1, 1A, 1B: Multi-display system, 2, 2B: Image output device, 3 (3A, 3B), 4 (4A, 4B), 5 (5A, 5B) ... Projector (image display device), 32: Image formation Means, 311 ... Storage means, 313, 313A ... Time acquisition means, 314, 314B ... Input normalization means, 315 ... Display normalization means, 317 ... Image selection means, 3142 ... Input time acquisition section, 3144 ... Input difference calculation section , 3145 ... input counter calculation unit, 3146 ... input counter addition unit, 3147 ... virtual input time calculation unit, 3148 ... association unit, 314A ... input counter advance, 314B2 ... association unit (other association unit), 3154 ... display difference Calculation unit, 3155 ... Output counter calculation unit, 3156 ... Output counter addition unit, 3157 ... Set time calculation unit, 3158 ... Phase setting Part 3173 ... starting time addition part 3174 ... output time calculation part 3175 ... image selection part 3176 ... image output part 3178 ... output counter raising part, SB01 ... display update cycle acquisition step, SB02 ... current time acquisition step, SB03 ... origin time acquisition step, SB04 ... display difference acquisition step, SB05 ... output counter calculation step, SB07 ... set time calculation step, SB08 ... phase setting step.

Claims (10)

A multi-display system comprising: a plurality of image display devices that display images according to input image signals; and an image output device that outputs the image signals to each of the plurality of image display devices,
Each of the image display devices is
An image forming unit configured to drive at a predetermined display update cycle and form an image according to the image signal;
Time acquisition means for acquiring the current time;
Storage means for storing a preset starting time;
Display normalization means for normalizing the display update period and the phase of the display update period,
The display normalizing means includes
A multi-display system, wherein a start timing of the display update cycle is matched with a set time calculated from the starting time and the current time. The multi-display system according to claim 1.
The display normalizing means includes
A display difference calculation unit for calculating a difference between the current time and the start time;
An output counter calculation unit that calculates a minimum integer value equal to or greater than a value obtained by multiplying the display update cycle by the difference;
An output counter addition unit for adding the starting time to a value obtained by dividing the output counter by the display update period;
A set time calculator that sets the time according to the value calculated by the output counter adder as the set time;
A multi-display system comprising: a phase setting unit that synchronizes the display update cycle start timing with the set time. The multi-display system according to claim 2,
Each of the image display devices is
A multi-display system comprising input normalizing means for normalizing image information in units of frames included in the image signal in accordance with an input cycle of the image information. The multi-display system according to claim 3,
The input normalization means includes:
An input time acquisition unit for acquiring an input time input by the image information;
An input difference calculation unit that calculates a difference between the input time and the start time;
An input counter calculation unit that calculates, as an input counter, a minimum integer value equal to or greater than a value obtained by multiplying the difference by the input period;
Each time the image information is input, the input counter is incremented by 1 to the input counter;
An input counter addition unit for adding the starting time to a value obtained by dividing the input counter by the input period;
A virtual input time calculation unit that calculates a time corresponding to the value calculated by the input counter addition unit as a virtual input time;
A multi-display system comprising: an association unit that associates the image information with the virtual input time. The multi-display system according to claim 3,
The image output device includes:
The image signal is output including the image information and time information related to the time according to the output cycle of the image information,
The input normalization means includes:
A multi-display system comprising: another association unit that associates the output time with the image information related to the output time, using the output time as a virtual input time. The multi-display system according to claim 4 or 5,
Each of the image display devices is
An image selection unit that selects the image information normalized by the input normalization unit and outputs the image information to the image forming unit;
The image selection means includes
An output counter increment that adds 1 to the output counter each time an image related to the image information input to the image forming unit is displayed by the image forming unit;
A starting point time adding unit that adds a value obtained by dividing the output counter added by the output counter raising part by the display update period to the starting point time;
An output time calculation unit that calculates a time corresponding to the value calculated by the start time addition unit as an output time;
An image selection unit that selects the image information before the output time and the virtual input time closest to the output time;
A multi-display system comprising: an image output unit that outputs the image information selected by the image selection unit to the image forming unit. The multi-display system according to any one of claims 1 to 6,
The time acquisition means includes
A multi-display system, wherein the current time is acquired based on time information included in radio waves input from outside. An image display device that displays an image according to input image information,
An image forming unit configured to drive at a predetermined display update cycle and form an image according to the image information;
Time acquisition means for acquiring the current time;
Storage means for storing a preset starting time;
A display normalizing means for normalizing the display update cycle and the phase of the display update cycle;
The display normalizing means includes
An image display device, wherein the display update cycle start timing is matched with a set time calculated from the starting time and the current time. Each image display device of a multi-display system comprising: a plurality of image display devices that display images according to input image signals; and an image output device that outputs the image signals to each of the plurality of image display devices. An image display method used to align the display timing of the image by each image display device,
A display update cycle acquisition step of acquiring a display update cycle of the image by the image display device;
A current time acquisition step for acquiring the current time;
A starting time acquisition step of acquiring a preset starting time;
A display difference acquisition step for acquiring a difference between the current time and the start time;
An output counter calculation step of calculating, as an output counter, a minimum integer value equal to or greater than a value obtained by multiplying the display update cycle by the difference;
A set time calculation step of calculating a time according to a value obtained by adding the starting time to a value obtained by dividing the output counter by the display update period, as a set time;
And a phase setting step of adjusting the start timing of the display update cycle to the set time. By each image display device of a multi-display system comprising: a plurality of image display devices that display images according to input image signals; and an image output device that outputs the image signals to each of the plurality of image display devices. An image display program that is executed and aligns display timings of the images by the image display devices,
In the image display device,
A display update cycle acquisition step of acquiring a display update cycle of the image by the image display device;
A current time acquisition step for acquiring the current time;
A starting time acquisition step of acquiring a preset starting time;
A display difference acquisition step for acquiring a difference between the current time and the start time;
An output counter calculation step of calculating, as an output counter, a minimum integer value equal to or greater than a value obtained by multiplying the display update cycle by the difference;
A set time calculation step of calculating a time according to a value obtained by adding the starting time to a value obtained by dividing the output counter by the display update period, as a set time;
An image display program for executing a phase setting step for adjusting a start timing of the display update cycle at the set time.

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