JPH057374A - Stereoscopic image pickup device - Google Patents

Abstract

PURPOSE:To eliminate the need for change of an area of a light shield part of a prism and to keep an area of a stereoscopic picture comparatively large even when a stop is changed in response to the surrounding lightness or the like. CONSTITUTION:The image of a light having a horizontal parallax made incident from a 1st prism 11 is formed onto a solid-state image pickup element 22 as optical images 31L, 31R having a horizontal parallax through a lens 21 being a component of a solid-state image pickup device 20. An electronic stop 32 to vary an incident luminous quantity by varying a storage time of a light made incident in the solid-state image pickup element 22 is provided to the solid-state image pickup device 20. Even when a stop is varied by using an electronic stop 32, a cross sectional area of a ray bundle of the incident light, in other words, the visual field is unchanged. Thus, even when the stop is changed in response to the surrounding lightness or the like, a 1st prism 11 having a light shield mask 13 with a prescribed area not requiring the change of the area of the light shield part is in use and the area of the stereoscopic picture is kept comparatively large.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a stereoscopic image pickup apparatus capable of viewing a subject as a stereoscopic image.

[0002]

2. Description of the Related Art Conventionally, a common subject is photographed by two left and right video cameras, an output signal from the video cameras is supplied to two monitors, and optical images on these monitors are combined by a half mirror. However, a stereoscopic camera has been proposed in which an image of a subject can be viewed as a stereoscopic image by viewing the combined optical image with orthogonal polarization filter glasses.

However, since such a stereoscopic camera requires two video cameras inevitably, the structure becomes complicated and the apparatus as a whole becomes relatively large and expensive.
It was unsuitable as a stereoscopic imaging device for consumer use, for example, home use.

In order to solve this inconvenience, the applicant of the present invention has proposed a technique capable of obtaining a stereoscopic image with a single video camera in Japanese Patent Laid-Open No. 59-30390. Hereinafter, a camera according to this technology is referred to as a prism type stereoscopic camera for convenience.

In this prism type stereoscopic camera, a first prism is arranged in front of the lens of one video camera. The first prism separates light having image information from a common subject into two lights having left and right parallax, and then the lens forms an optical image having the left and right parallax on an image receiving surface of the video camera. Make them image. Then, an optical image based on an electric signal based on the formed optical image is displayed on the left and right on the screen of the monitor. This displayed optical image is viewed through a second prism in which prism elements are arranged symmetrically. When viewing through this second prism, the optical image displayed on the left side is viewed by the left eye through the prism element on the left side, while the optical image displayed on the right side is viewed by the right eye through the prism element on the right side. , Is a technology that makes it possible to see stereoscopic images.

[0006]

By the way, in the above-mentioned conventional prism type stereoscopic camera, as shown in FIG. 2A, the central portion 4 of the left and right optical images 2 and 3 displayed on the monitor 1 is used.
Then, for example, an overlapping portion of the optical images having the width d1 occurs. Therefore, when viewed through the second prism, the overlapping portion causes the overlapping portion in the stereoscopic image, which causes a problem that the image becomes difficult to see.

In order to solve this problem, in the above-mentioned conventional prism type stereoscopic camera, a light shielding mask is formed on the first prism. By forming a light-shielding mask on the first prism, as shown in FIG. 2B, a non-image portion 5 on the band where the optical image is not displayed is formed in the central portion 4 of the screen, and the left and right optical images 2 and 3 are formed. The overlapping portion can be eliminated, and a high-quality stereoscopic image can be viewed.

However, when the amount of light having image information from the subject becomes small, in other words, when the surroundings become dark, the aperture of the video camera is increased in order to increase the amount of light incident on the image receiving surface. It is necessary to open the diaphragm. When the aperture stop is opened, as shown in FIG. 2C, the width d2 in which the width of the overlapping portion is widened as compared with FIG. 2A.
An overlapping portion of (d2> d1) occurs in the central portion 4 '.

Therefore, in order to correspond to the opened state of the aperture stop, a wide light-shielding mask corresponding to the width d2 of the central portion 4'is formed on the first prism from the beginning. As shown in 2D, the overlapping portion of the images becomes the non-image portion 5 '.

However, in the state where the wide light-shielding mask is formed on the first prism, the surrounding area becomes bright again and the aperture stop is closed, as shown in FIG.
As shown in E, the width d3 (d3>
d2), the non-image portion corresponding to the width of the light-shielding mask is enlarged to the non-image portion 5 ″, and the image display area of the left and right optical images 2 and 3 is reduced. There is a problem that the area of the stereoscopic image observed by the left and right eyes is reduced based on the optical images 2 and 3, and so-called stereoscopic effect is reduced.

In order to solve these problems, it is conceivable to prepare several types of first prisms having light-shielding masks having different widths depending on the aperture amount of the aperture diaphragm, but it is possible to prepare them according to the ambient brightness. The replacement work becomes extremely complicated, and the problem of being unsuitable as a consumer-use, for example, a home-use stereoscopic imaging device reoccurs. Moreover, for example, even when the first prism having the daytime light-shielding mask and the first prism having the nighttime light-shielding mask are prepared, the first prism having the daytime light-shielding mask is formed. 1
There is a problem that it is not possible to respond promptly when the incident light amount suddenly changes, such as when entering the tunnel during shooting using the prism.

The present invention has been made in view of the above problems, and it is not necessary to change the area of the light-shielding portion of the prism even if the diaphragm is changed, and the area of a stereoscopic image is kept relatively large. It is an object of the present invention to provide a stereoscopic imaging device capable of performing the above.

[0013]

The stereoscopic image pickup device of the present invention comprises:
For example, as shown in FIG. 1, a prism 11 that separates light L having image information from a common subject 10 into light having two left and right parallax with respect to the optical axis 12, and the prism 11.
And a solid-state image pickup device 20 having a lens 21 arranged behind 1 to converge the light having the left-right parallax and form two optical images 31L, 31R having the left-right parallax on the solid-state image pickup element 22. The prism 11 is formed with a light-shielding portion 13 including a portion through which the optical axis 12 of the prism 11 passes, and the solid-state image pickup device 20 changes the light accumulation time to the solid-state image pickup element 22. Accordingly, the electronic diaphragm 32 that changes the amount of incident light is provided.

[0014]

According to the stereoscopic image pickup device of the present invention, the solid-state image pickup device 2
By the lens 21 which constitutes 0, the light having the left-right parallax incident from the prism 11 is converted into the optical image 3 having the left-right parallax.
1L and 31R are used to form an image on the solid-state image pickup device 22, and the solid-state image pickup device 20 has an electronic diaphragm that changes the amount of incident light by changing the accumulation time of light incident on the solid-state image pickup device 22. Since 32 is provided, even if the diaphragm is changed by the electronic diaphragm 32, the cross-sectional area of the ray bundle of incident light, in other words, the field of view does not change.

Therefore, it is possible to use the prism 11 having the light-shielding portion 13 of a constant area which does not need to change the area of the light-shielding portion even if the diaphragm changes, and the area of the stereoscopic image can be kept relatively large. You can

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the stereoscopic image pickup apparatus of the present invention will be described below with reference to the drawings. In the drawings referred to below, parts corresponding to those shown in FIGS. 2A to 2E described above are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, reference numeral 10 denotes a subject, and the light L having image information from the subject 10 is separated by the first prism 11 into light having two left and right parallax with respect to the optical axis 12. As the first prism 11, as shown in FIG. 1, a prism having an isosceles triangular cross section or a rhombic cross section can be used.

The first prism 11 is provided with a light-shielding mask 13 having a width w for forming a light-shielding portion including a portion through which the optical axis 12 passes. As the light shielding mask 13, a chromium vapor deposition mask or the like can be used.

The light having two left and right parallaxes obtained by being separated by the first prism 11 is the solid-state image pickup device 20.
Is incident on the lens 21 constituting the. Solid-state imaging device 20
In addition to the lens 21, is a solid-state image sensor 22 such as an interline CCD, a signal processing circuit 23, a storage time control circuit 2
4, a drive circuit 25, a storage time setting switch 25, and a system controller 35.

The light having the above two left and right parallaxes is reflected by the lens 2
Optical image 3 converged by 1 and having two left and right parallaxes
Images are formed on the solid-state image sensor 22 as 1R and 31L.

The solid-state image pickup device 20 is provided with an electronic diaphragm 32 for varying the amount of incident light incident on the solid-state image pickup element 22. The electronic diaphragm 32 includes a solid-state image sensor 22, a drive circuit 25 for the solid-state image sensor 22, and a storage time control circuit 24.

That is, for example, of the charges accumulated in each photoelectric conversion portion which constitutes the solid-state image pickup device 22, a predetermined charge is applied to the vertical C in the horizontal blanking period of the television signal.
An optical image 3 having the above-mentioned left and right parallax is swept onto a CD or an overflow drain, and then on the photoelectric conversion section.
The signal charges corresponding to 1R and 31L are stored in the storage time set value Ts.
It is adapted to accumulate during (corresponding to the shutter speed). Therefore, the diaphragm of the electronic diaphragm 32 does not change the cross-sectional area of the light flux of the light L incident on the solid-state imaging device 20. In other words, this electronic diaphragm is not an aperture diaphragm that changes the aperture area but a diaphragm that has a constant aperture area and controls the amount of received light by the light receiving time.

The storage time set value Ts can be controlled manually by the set value of the storage time setting switch 25 or automatically by the system controller 35 by a signal according to the amount of received light from the signal processing circuit 23. Examples of the technology of this electronic diaphragm include the technology disclosed in Japanese Patent Application Laid-Open No. 64-29067 by the present applicant. This technique discloses a technique for automatically determining the amount of diaphragm when receiving light, based on the average light intensity of a plurality of fields imaged before that. The electronic diaphragm is known as an electronic shutter.

The signal charges corresponding to the optical images 31L and 31R having the above-mentioned left and right parallax output from the solid-state image pickup device 22 are converted into the video signal SV by the signal processing circuit 23, and then,
It is supplied to the monitor 36, which is an image display means such as a television, through the output terminal 26.

A second prism 38 having a light-shielding mask 37 functioning as a baffle is formed in the center in front of the screen of the monitor 36. , 39R to see the optical images 2 and 3 having left and right parallax displayed on the screen of the monitor 36 through the second prism 38 of the subject 1
You can see a stereoscopic image of 0. Of the optical images 2 and 3 having left and right parallax displayed on the screen of the monitor 36 without using the second prism 38, the left optical image 2 is the left optical image 2 and the right optical image 3 is the right eye 39L.
By viewing with R, a stereoscopic image of the subject 10 can be similarly viewed.

In the example of FIG. 1, the width w of the light shielding mask 13
When the optical image having the left-right parallax displayed on the monitor 36 is directly viewed by the eyes 39L and 39R (the second prism 38 is removed from the optical path),
The width may be adjusted to a width corresponding to the minimum width in which the overlapping portions in the central portions of the optical images 2 and 3 having left and right parallaxes are eliminated. The minimum width at which there is no overlapping portion is shown as the minimum width d5, and the non-image portion is shown as the non-image portion 37. The width w of the light-shielding mask 13 can be adjusted by the manufacturer, and the general consumer can use the stereoscopic image pickup device adjusted to the optimum state in this manner to adjust the light-shielding mask 13 of the first prism 11. A stereoscopic image having a relatively large area can be viewed without paying attention to the width ω of.

As described above, according to the above-described embodiment, since the electronic diaphragm 32 that changes the amount of incident light by changing the accumulation time of the light incident on the solid-state image pickup device 22, the diaphragm is changed. However, the cross-sectional area of the bundle of incident light, in other words, the field of view does not change.

Therefore, even if the diaphragm changes, it is not necessary to change the width w of the light-shielding mask 13 formed on the first prism 11, that is, the light-shielding area, and the first prism 11 with the light-shielding mask 13 is surrounded. It is possible to obtain a stereoscopic imaging device that does not require replacement according to the brightness of the. Therefore, even if the amount of incident light suddenly changes, such as when entering a tunnel during shooting as described in the section of the related art, it is possible to change the aperture amount (accumulation time) by the electronic aperture 32. so,
It is possible to obtain a stereoscopic image having a relatively wide field of view.

The present invention is not limited to the above-described embodiments, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0030]

As described above, according to the three-dimensional image pickup device of the present invention, the solid-state image pickup device uses the lenses constituting the solid-state image pickup device to convert light having a left-right parallax incident from the prism into an optical image having a left-right parallax. This solid-state image pickup device is provided with an electronic diaphragm for changing the amount of incident light by changing the accumulation time of light incident on the solid-state image pickup device while forming an image above. Therefore, even if the diaphragm is changed by the electronic diaphragm, the cross-sectional area of the light flux of the incident light, in other words, the field of view is not changed.

Therefore, it is not necessary to change the area of the light-shielding portion even if the diaphragm changes according to the ambient light or the like, so that it is possible to use a prism having a light-shielding portion having a constant area. Further, there is an effect that the area of the stereoscopic image can be kept relatively large.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a stereoscopic imaging device according to the present invention.

FIG. 2 is a diagram used for explaining a relationship between an aperture stop and a non-image portion by a light-shielding mask.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Subject 11 Prism 12 Optical axis 13 Light-shielding part 20 Solid-state imaging device 22 Solid-state imaging device 31L, 31R Optical image 32 Electronic diaphragm

Claims (1)

Claim: What is claimed is: 1. A prism for separating light having image information from a common subject into light having two left and right parallax with respect to an optical axis, and a prism disposed behind the prism, A solid-state imaging device having a lens that converges light having a left-right parallax and forms an optical image having two left-right parallaxes on a solid-state imaging device, wherein the prism has a portion through which the optical axis of the prism passes. A light-shielding portion is formed, and the solid-state image pickup device is provided with an electronic diaphragm that changes the amount of incident light by changing the accumulation time of light to the solid-state image pickup device. A stereoscopic imaging device characterized by the above.