JP3450401B2 - Video display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a one-dimensional display means, and scans a one-dimensional image displayed on the one-dimensional display means to display a two-dimensional image. The present invention relates to a video display device for performing the above. 2. Description of the Related Art As a conventional video display device, for example, as shown in FIG. 5, a one-dimensional display element 1 and a rotary polygon mirror 2 are used.
And the sequential elements 1-1 to 1-n of the one-dimensional display element 1
The one-dimensional image displayed on the one-dimensional display element 1 is scanned by the rotary polygon mirror 2 while the video signals of n scanning lines of one frame to be displayed are supplied in parallel, and as shown in FIG. There is known an apparatus which displays an image of one frame having n scanning lines. [0003] However, in the above-described conventional video display device, the number of one-dimensional display elements 1 needs to be equal to the number of scanning lines in one frame. There is a problem that as the number of scanning lines increases, the number of elements increases and the cost increases. [0004] The present invention has been made in view of such a conventional problem, without reducing the resolution.
It is an object of the present invention to provide a video display device that is appropriately configured so that the number of one-dimensional display elements can be made smaller than the number of scanning lines in one frame, and thus can be inexpensive. In order to achieve the above object, according to the present invention, there is provided a one-dimensional display means for displaying a one-dimensional image, and a displacement for displacing the one-dimensional display means substantially in the one-dimensional direction. Means, and a reflecting surface for reflecting a one-dimensional image displayed on the one-dimensional display means, and synchronizing the reflecting surface with an axis substantially parallel to the one-dimensional direction in synchronization with the displacement of the one-dimensional display means. Scanning means for rotating and displacing to the center, and synchronizing with the displacement of the one-dimensional display means by the displacement means, switching video signals of a plurality of different scanning lines, and changing the video signals of the plurality of scanning lines to the one-dimensional Video signal switching means for supplying in parallel to sequential elements of the display means. In the present invention, the video signals of a plurality of different scanning lines are switched by the video signal switching means in synchronization with the displacement of the one-dimensional display means by the displacement means, and the video signals of the plurality of scanning lines are changed. Are supplied in parallel to the sequential elements of the one-dimensional display means, and are scanned by the reflecting surface of the scanning means which rotates and displaces in synchronization with the displacement of the one-dimensional display means. Here, since the one-dimensional display means is displaced substantially in the one-dimensional direction, the scanning position of the one-dimensional image on the reflecting surface is moved in parallel with each displacement of the one-dimensional display means. Therefore, for example, when a video signal of one frame is displayed in two fields, the one-dimensional display means is displaced to the first position and the second position by the displacement means in synchronization with the vertical synchronization signal of the video signal. At the same time, if the video signals of the sequential fields are switched, and the video signals of all the scanning lines of each field are supplied in parallel to the sequential elements of the one-dimensional display means, that is, the odd field at the first position is replaced with the second field. If an even field is scanned at the position, a one-frame video signal can be displayed by the one-dimensional display means having the same number of elements as the number of scanning lines in one field. FIG. 1 shows a reference example developed with the present invention. This reference example is applied to a face- or head-mounted image display device having a right-eye optical system 11R and a left-eye optical system 11L.
Has a one-dimensional display element 12R, a polygon mirror 13R, a motor 14R, and an imaging lens 15R. The one-dimensional display element 12R is composed of, for example, an LCD or an LED array, and reflects a one-dimensional image displayed on the one-dimensional display element 12R with a polygon mirror 13R, and passes the image through an imaging lens 15R to the right eye 16R. To lead. In this reference example, the polygon mirror 13R has six first to sixth sequential reflecting surfaces, and these are arranged in one-dimensional direction of the one-dimensional display element 12R, that is, an axis substantially parallel to the element arrangement direction. Is rotated in a predetermined direction by the motor 14R. In this reference example, in order to display a television signal of the NTSC system, video signals of all the scanning lines of each field are supplied in parallel to the one-dimensional display element 12R sequentially by switching the field by field. To do. In addition, the polygon mirror 13R sets the inclination of the six reflecting surfaces of the one-dimensional display element 12R with respect to the one-dimensional direction,
The first, third, and fifth reflecting surfaces are made different from the second, fourth, and sixth reflecting surfaces, and these are rotated by one surface in one field period in synchronization with the vertical synchronizing signal of the television signal. Let it do. As described above, by scanning the one-dimensional image displayed on the one-dimensional display element 12R while rotating the polygon mirror 13R, as shown in FIG. The image of the odd field consisting of the odd scanning line indicated by the solid line is led to the right eye 16R by the second, fourth and sixth reflecting surfaces, and the image of the even field consisting of the even scanning line indicated by the broken line is guided to the right eye 16R. To do. The left-eye optical system 11L is provided with a one-dimensional display element 12L, a polygon mirror 13L, a motor 14L, and an imaging lens 15L, and has the same configuration as the right-eye optical system 11R. In this reference example, the polygon mirror 13R for the right eye and the polygon mirror 1 for the left eye
With 3L, the rotation direction is reversed. FIG. 3 is a block diagram showing a signal processing circuit according to the reference example. An NTSC television signal is supplied to a synchronization separation circuit 21 to be separated into a synchronization signal and a video signal.
2. The left and right one-dimensional display elements 12L and 12R are supplied to the left and right display element drivers 23L and 23R and the left and right motor drivers 24L and 24R in synchronization with the horizontal synchronization signal, and the left and right motors 14L and 14R are driven. Are synchronized with the vertical synchronizing signal, and the left and right polygon mirrors 13L, 13L
3R is driven to rotate by one surface during one field period. The video signal is supplied to an A / D converter 25.
And converts the digital video signals of the successive fields into two field memories 26 under the control of the address generation circuit 22 in synchronization with the vertical synchronizing signal.
-1 and 26-2. The digital video signals of the sequential fields stored in the field memories 26-1 and 26-2 are stored in the field memories 26-1 and 26-2.
-1 and 26-2 are alternately selected by the address generating circuit 22 in synchronization with the vertical synchronizing signal, and simultaneously read out one column at a time in synchronism with the horizontal synchronizing signal. The digital video signals are read out in parallel, and the digital video signals are subjected to analog conversion processing in parallel by the corresponding D / A converters 27-1 and 27-2, and supplied in parallel to the left and right one-dimensional display elements 12L and 12R, respectively. Then, the one-dimensional images sequentially displayed on the one-dimensional display elements 12L and 12R are scanned by the polygon mirrors 13L and 13R to form a two-dimensional image. That is, first, when the video signal of the first field is stored in the field memory 26-1, the video signal of the second field is stored in the field memory 26-2, and the first video signal stored in the field memory 26-1 is stored. The video signals of all the scanning lines of the field are sequentially read out in parallel and supplied in parallel to the left and right one-dimensional display elements 12L and 12R in order to display them.
The video signals of all the scanning lines of the second field stored in 6-2 are sequentially read out in parallel, and displayed on the left and right one-dimensional display elements 12L and 12R in the same manner. -1 is stored. By performing this operation on the video signal of the sequential field, the video signal of the odd field is stored in the field memory 26-1 and the video signal of the even field is stored in the field memory 26-2 in synchronization with the vertical synchronization signal. Meanwhile, the video signals of all the scanning lines of the sequential field are sequentially read out in parallel in synchronization with the horizontal synchronizing signal and supplied to the left and right one-dimensional display elements 12L and 12R in order to display them in parallel. The sequential one-dimensional images are converted to polygon mirrors 13L,
Scan by 13R to form a two-dimensional image. Therefore, according to this reference example, the number of left and right one-dimensional display elements 12L and 12R can be made equal to half the number of scanning lines in one frame, that is, the number of scanning lines in one field. As much as possible, the resolution is not reduced at all. FIG. 4 shows a main part of an embodiment of the present invention. This embodiment is applied to a face- or head-mounted image display device having optical systems for the left eye and the right eye, as in the above reference example. FIG. 4 shows one of the optical systems, for example, the left eye 10 shows the optical system 11L for use. In this embodiment, the polygon mirror 13
A galvanometer mirror 31L is provided in place of L, and the one-dimensional display element 12L is replaced with a piezoelectric element 32L as a displacement means.
, So as to be displaced in a substantially one-dimensional direction.
In this way, the one-dimensional image displayed on the one-dimensional display element 12L is reflected by the galvanomirror 31L, and the image is guided to the left eye 16L via the imaging lens 15L.
The other optical system for the right eye is similarly configured. In such a configuration, the one-dimensional display element 12
When L is displaced in a substantially one-dimensional direction by the piezoelectric element 32L, the scanning position of the one-dimensional image on the galvanomirror 31L moves in parallel with each displacement of the one-dimensional display element 12L. Therefore, when displaying an NTSC television signal, the one-dimensional display element 12L is moved by the piezoelectric element 32L to the first position corresponding to the scanning line of the odd field and the even number in synchronization with the vertical synchronizing signal of the video signal. In addition to displacing to the second position corresponding to the scanning line of the field and rotating the galvanomirror 31L, the video signals of all the scanning lines of each field are sequentially synchronized with the horizontal synchronizing signal and the one-dimensional display element 12L is rotated. If the sequential elements are sequentially supplied in parallel, ie, the odd field at the first position is
When the even field is scanned at the position of, the one-dimensional display element 12L having the number of elements equal to the number of scanning lines of one field can display a video signal of one frame, as in the above-described reference example. The same effect as the example can be obtained. Note that the present invention is not limited to the above-described embodiment, and various modifications or changes can be made. For example, in the above-described embodiment, an NTSC television signal of one frame is displayed in two fields, but an interlaced video signal forming one frame in three or more fields is displayed. Can also. For example, in the case of three fields and one frame, the one-dimensional display element may be displaced to the first, second, and third positions, and the video signals of the sequential fields may be scanned in parallel. When a polygon mirror having six reflecting surfaces is used as in the above-described reference example, the inclination of the six reflecting surfaces is set according to the number of fields in one frame, for example, in the case of three fields and one frame. 3
The video signals of the sequential fields are respectively parallel in three different ways, that is, differently for the first and fourth reflecting surfaces, the second and fifth reflecting surfaces, and the third and sixth reflecting surfaces. Scan. Also in this case, the number of one-dimensional display elements can be set to the number of scanning lines in one field. Therefore, in the case of three fields and one frame as described above, one frame can be fully scanned. The number of elements can be reduced to 1/3 of the number of lines, and the resolution is not reduced. The video signal to be displayed is not limited to the above-mentioned interlace type, and the present invention can be effectively applied to a non-interlace type. In this case, the video signal of one frame is stored in the frame memory, the video signals of a plurality of different scanning lines are read out in parallel, supplied to the one-dimensional display element, and scanned by the galvanomirror. That is, the one-dimensional display element is displaced to, for example, the first, second, and third positions, and the video signal of the (3n + 1) scanning line at the first position is transmitted to the (3n) at the second position.
The video signal of the (n + 2) scanning line is supplied to the third position at (3n)
(Where n is 0, 1, 2,...)
) May be scanned in parallel. With this configuration, the number of one-dimensional display elements can be reduced to ３ of the total number of scanning lines in one frame without any degradation in resolution. When a polygon mirror having six reflecting surfaces is used as in the above-mentioned reference example, for example, the inclinations of the reflecting surfaces are set to the first and fourth reflecting surfaces and the second and second reflecting surfaces. 5 is different from the third and sixth reflecting surfaces, and the video signal of the (3n + 1) scanning line on the first and fourth reflecting surfaces is changed to (3n + 2) on the second and fifth reflecting surfaces. ) May be scanned in parallel with the video signal of the scanning line, and the video signal of the scanning line of (3n) may be scanned in parallel by the third and sixth reflecting surfaces. Also in this case, the number of one-dimensional display elements can be reduced to 1/3 of the total number of scanning lines in one frame without any degradation in resolution. By rotating the polygon mirrors at a high speed while changing the inclinations of the six reflecting surfaces by a predetermined difference, the number of one-dimensional display elements is reduced to 1/6 of the total number of scanning lines in one frame. You can also. Further, in the above-described example, the same image is displayed by the left and right optical systems. However, independent video signal memories are provided corresponding to the left and right optical systems, and different memories, For example, by storing and displaying left and right images having binocular parallax, it is possible to configure so that a stereoscopic image can be observed by an observer. In addition, the present invention is not limited to the above-described face or head mounted image display device, and can be effectively applied to other image display devices. As described above, according to the present invention, a one-frame image can be displayed without lowering the resolution by using one-dimensional display means having a smaller number of elements than the number of scanning lines in one frame. Because it can be displayed, it can be inexpensive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a reference example developed with the present invention. FIG. 2 is a diagram for explaining the operation of FIG. 1; FIG. 3 is a block diagram illustrating an example of a signal processing circuit. FIG. 4 is a diagram showing a main part of one embodiment of the present invention. FIG. 5 is a diagram showing a conventional video display device. FIG. 6 is a diagram for explaining the operation of FIG. 5; [Description of Signs] 11L Optical system for left eye 11R Optical system for right eye 12L, 12R One-dimensional display element 13L, 13R Polygon mirror 14L, 14R Motor 15L, 15R Imaging lens 16L Left eye 16R Right eye 21 Synchronous separation circuit 22 Address generation circuit 23L, 23R Display element driver 24L, 24R Motor driver 25 A / D converter 26-1, 26-2 Field memory 27-1, 27-2 D / A converter 31L Galvano mirror 32L Piezoelectric element

Claims (1)

(57) [Claims 1] One-dimensional display means for displaying a one-dimensional image, displacement means for displacing the one-dimensional display means substantially in one-dimensional direction, and one-dimensional display means A scanning unit having a reflecting surface for reflecting the displayed one-dimensional image, synchronizing the reflecting surface with the displacement of the one-dimensional display unit, and rotating and displacing around an axis substantially parallel to the one-dimensional direction; Synchronously with the displacement of the one-dimensional display means by the displacement means, switching the video signals of a plurality of different scanning lines, and the video signals of the plurality of scanning lines in parallel to the sequential elements of the one-dimensional display means. A video display device comprising: a video signal switching means for supplying.