JPH0576181U - Stereoscopic system video camera - Google Patents

Abstract

(57) [Abstract] [Purpose] A stereoscopic image is recorded in a stereoscopic system in which a housing is attached to the front of a video camera and a stereoscopic image can be recorded by a mirror, a half mirror and a liquid crystal shutter provided in the housing. Be able to change the distance you can. [Structure] A housing 3 is provided in front of an objective lens 2 of a video camera 1, and a half mirror 5, liquid crystal shutters 6 and 7 and a mirror 4 are provided inside the housing 3 to switch between the liquid crystal shutters 6 and 7. The left and right images are alternately recorded by the video camera 1. At this time, the position of the mirror 4 is changed so that the visual field range that can be viewed as a stereoscopic image is changed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a stereoscopic system video camera capable of changing a visual field range that can be observed as a stereoscopic image.

[0002]

[Prior Art]

 As stereoscopic system cameras, still cameras for still images and movie cameras and video cameras for moving images are targeted, and their development is proceeding. Among these, as a prior art relating to a video camera, there is known a method in which a light beam entering an objective lens of a video camera is divided into two parts into right and left parts, and the light parts are alternately made incident by a shutter having an appropriate structure. (See US Pat. No. 3,821,466 and US Pat. No. 3,90 3,358).

In these patent specifications, a mirror and a half mirror are arranged in front of an objective lens of a video camera to split a light beam entering the objective lens into two right and left parts. The shutter is switched so that light enters the objective lens alternately.

The principle of one example will be described with reference to FIG. In this figure, 1 is a video camera and 2 is its objective lens. A housing 3 is provided at the front of the objective lens 2 and is held so that its position does not change by an appropriate means. A mirror 4, a half mirror 5, and liquid crystal shutters 6 and 7 are housed inside the housing 3 in the following positional relationship. That is, at the position in front of the objective lens 2 in the housing 3, the half mirror 5 is held at an angle of 45 ° with respect to the optical axis of the objective lens 2, and to the side and front of the half mirror 5. The liquid crystal shutters 6 and 7 are held at an appropriate distance.

The half mirror 5 receives light rays in two directions orthogonal to each other as shown by a broken line in the drawing, one half of the light rays is transmitted, and the other light ray is half of the reflected light. One light beam is guided to the direction of the objective lens 2. Inside the housing 3, a mirror 4 is arranged in front of the liquid crystal shutter 6 (side to the optical axis of the objective lens) in the same direction as the half mirror 5. As a result, the mirror 4 refracts the light beam from the front in the direction of 90 ° and makes it enter the liquid crystal shutter 6.

The liquid crystal shutter 6 has a structure as shown in FIG. To explain this, the structure is such that a liquid crystal 9 having a transparent electrode 8 embedded in the center is sandwiched between glass substrates 10 and a polarizing plate 11 is attached to the outside thereof. With this structure, when the polarization axes of the polarizing plates 11 on both sides are deviated by 90 °, the polarization axis of the liquid crystal is deviated by 90 ° so that the state becomes transparent. When a signal is applied to the transparent electrode 8, the polarization of the liquid crystal is changed. It will be lost and kept opaque.

Therefore, in the structure shown in FIG. 3, the liquid crystal shutters 6 provided on the front and side of the half mirror 5 are alternately made transparent or opaque, and the objective lens 2 of the video camera 1 has two of them. The light rays that have passed through the liquid crystal shutter 6 are alternately incident. The video camera 1 records this, and at the time of reproduction, the screen is viewed alternately by the left eye and the right eye by glasses, and thus it is recognized as a stereoscopic image.

In the conventional device described above, the area that can be seen as a stereoscopic image is fixed due to its structure, and this cannot be changed. By the way, when a person looks at an object, he or she sees the object at each viewing angle of both eyes, but the left and right eyes are directed inward at an angle, and the fields of view should intersect at a certain distance from the eyes. It has become. Since each eye has a view angle, the depth of view increases when the view angles widen and intersect, which acts to make an object look three-dimensional.

In this case, the distance at which an object looks three-dimensionally is determined by the distance between both eyes of a human being, and this cannot be changed. However, it would be extremely convenient if the three-dimensionally visible distance can be changed. In other words, if it becomes larger, the distant landscape that used to look flat will be seen three-dimensionally, which will be useful for surveying and grasping disaster situations. When observing a distant scene with a video camera without using the naked eye, in the structure shown in FIG. 3, the optical axis R passing through the liquid crystal shutter 7 and the half mirror 5 and entering the objective lens 2 of the video camera 1 and the mirror. The distance a from the optical axis L toward the half mirror 5 after being refracted by 90 ° by 4 determines the three-dimensionally visible distance.

[0010]

[Problems to be solved by the device]

 When an object is viewed three-dimensionally, the three-dimensionally visible distance is fixed in the conventional structure. Therefore, if you want to change the stereoscopic distance, prepare several sets with different gaps between the mirror and the half mirror, and select them appropriately and attach them to the front of the objective lens of the video camera. Became. Therefore, it became very inconvenient for actual use.

The present invention has been made in view of this point, and it is an object of the present invention to provide a stereoscopic system video camera capable of continuously changing a stereoscopically visible distance with one set. ..

[0012]

[Means for Solving the Problems]

 As a means for solving the above-mentioned problems, the present invention provides a front part of an objective lens of a video camera with a part facing the objective lens and a housing having an opening at the front part, and the front part of the objective lens in the housing is provided. A half mirror having an angle of 45 ° with respect to the objective lens, and liquid crystal shutters on the front and side of the half mirror. In addition, a mirror that guides a light beam from the front to the liquid crystal shutter side is provided so as to be able to advance and retreat with respect to the liquid crystal shutter.

[0013]

With such a configuration, the range that can be viewed as a stereoscopic image is changed by changing the position of the mirror provided so as to be able to move forward and backward with respect to the liquid crystal shutter and changing the interval a in FIG. be able to.

[0014]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. A rail 12 is provided on the bottom of the housing 3 so that the mirror 4 can move along the rail 12. As a concrete structure of this portion, a boss (not shown) for engaging the mirror 4 with the rail 12 is provided on the mirror 12, and the boss is moved by a knob 13 provided on the outside of the housing 3. And so on. Of course, other structures may be used, but one that can be operated from outside the housing 3 is preferable.

With the structure that can be operated from the outside of the housing 3, it becomes possible to interlock with the zoom mechanism of the video camera 1. By interlocking in this way, it is possible to make the range that can be seen as a vertical image correspond to the viewing angle that changes depending on the zoom.

In the stereoscopic system video camera thus configured, the two liquid crystal shutters 6 and 7 are controlled so as to alternately transmit and block light while the video camera 1 is shooting. This control can be easily performed by a well-known technique by a semiconductor circuit (not shown). Now, assuming that the liquid crystal shutter 6 is in the transmissive state and the liquid crystal shutter 7 is in the shut-off state, the light beam from the front of the housing 3 hits the mirror 4 and is reflected by the mirror 4, and the liquid crystal shutter 6 in the transmissive state is reflected. It passes through to the half mirror 5, where it is reflected again and enters the objective lens 2 of the video camera 1. There is no light incident from the liquid crystal shutter 7 side in the cutoff state.

At the next moment, if the liquid crystal shutter 6 is turned off and the liquid crystal shutter 7 is turned on, the light passing through the liquid crystal shutter 7 passes through the half mirror 5 and then the objective lens 2 of the video camera 1. Light entering from the mirror 4 side is blocked by the liquid crystal shutter 6 and does not reach the half mirror 5. In this way, the light enters the objective lens 2 of the video camera 1 alternately, so that the scenes and the like that are aimed from different positions are alternately recorded on the recording screen. At the time of playback, you can view this as a stereoscopic image with glasses.

When viewing in this way, what happens when the position of the mirror 4 is changed by operating the knob 13. The position of the optical axis L with respect to the position-invariant optical axis R changes within the range of L _{1 to} L ₂ , and the distance from the optical axis R also changes within the range of a to b. As a result, it is possible to change the three-dimensionally visible distance by the same theory as the above-mentioned theory that the three-dimensionally visible distance is determined by the distance between human eyes. There is also a method to synchronize this operation with the zoom lens of the camera.

[0019]

[Effect of the device]

 Since the present invention is a stereoscopic system video camera configured as described above, it can change the stereoscopically visible distance that was unchanged in the prior art, so it looks flat in the past. The distant scenery that had been seen will be seen three-dimensionally, which will be useful for surveying and grasping disaster situations.

[Brief description of drawings]

FIG. 1 is a perspective view showing the external appearance of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the inside of FIG.

FIG. 3 is a sectional view of a conventional example.

FIG. 4 is a cross-sectional view of a liquid crystal shutter used in FIG.

[Explanation of symbols]

 1 Video Camera 2 Objective Lens 3 Housing 4 Mirror 5 Half Mirror 6 Liquid Crystal Shutter 7 Liquid Crystal Shutter 12 Rail

Claims (1)

[Scope of utility model registration request] 1. A front part of an objective lens of a video camera is provided with a part facing the objective lens and a housing having an opening at the front part thereof.
A half mirror having an angle of 45 ° with respect to the objective lens is provided in front of the objective lens in the housing, and liquid crystal shutters are provided at front and side portions of the half mirror. A stereoscopic system video camera, characterized in that a mirror for guiding a light beam from the front to the liquid crystal shutter side is provided on the side of the liquid crystal shutter located in the section so as to be able to move forward and backward with respect to the liquid crystal shutter.