JP3888847B2 - Wide-field imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wide-field imaging device, and more particularly to a technique that is effective when applied to improving and simplifying the video quality of a circular panoramic video imaging device.
[0002]
[Prior art]
Conventional techniques include the following.
(1) Some images are picked up using a super-wide-angle lens such as a fisheye lens, and distortion of the lens is corrected by signal processing. For example, a product of Interactive Pictures Corporation (Tennessee, USA) or a patent of International Business Machines Corporation (JP-A-8-55215).
[0003]
(2) There are some which combine two reflecting mirrors having a curved surface and take a picture of the entire circumference of the circumference at once with one camera, and develop the image taken in a ring shape into a panoramic image by signal processing. For example, “360-degree visual system (ODV)” (Mitsubishi Electric Advanced Technology Research Institute 1997).
[0004]
(3) There is one in which the same function as that of the reflecting mirror of (2) is realized by one wide viewing angle lens. For example, “360 degree camera system (PAL360 system)” (Tateyama Science Group February 26, 1998, Asahi Shimbun, March 12, 1998, Yomiuri Shimbun evening edition, etc.).
[0005]
(4) Some cameras rotate a single camera with respect to the whole sky, take a plurality of images, and synthesize them by signal processing. For example, camera pan head and panoramic image / all-sky image creation device (NHK Giken Yamauchi Yuko) (Japanese Patent Application No. 10-326506).
[0006]
(5) Some cameras arrange a large number of cameras on a spherical surface and synthesize images obtained from the cameras by signal processing. For example, “Development of an omnidirectional stereo system” (Softpia Japan, Hidekake Tanahashi, Proceedings of the 6th Image Sensing Symposium D-19).
[0007]
(6) Some line sensors and lenses rotate around a vertical axis to obtain a circular image. For example, a patent of Picker International Inc. (Japanese Patent Laid-Open No. 6-222481).
[0008]
[Problems to be solved by the invention]
However, in the prior art (1), the obtained image is greatly distorted by the lens, and distortion correction processing is necessary, and there are many useless areas with respect to the imaging area. Is significantly reduced. In addition, an expensive optical system such as a super-wide angle fisheye lens is required. In addition, the correction processing of the video signal is complicated, and an advanced signal processing device is required.
[0009]
In the prior arts (2) and (3), an image of the entire sky cannot be obtained (particularly the zenith portion). In addition, the obtained image is greatly distorted by the reflecting mirror, and distortion correction processing is necessary. In addition, there are many useless areas with respect to the imaging area, and the resolution particularly in the periphery of the image is significantly reduced by the correction. In addition, a special optical system such as a reflecting mirror is required. Further, the correction processing of the video signal is complicated, and an advanced signal processing device is required.
[0010]
In the prior arts (4), (5), and (6), in order to obtain an image of the entire sky, a plurality of images that are simultaneous or time-series are used, and precise joint processing of the obtained images is required.
[0011]
An object of the present invention is to provide a technique capable of easily capturing a high-resolution panoramic image of a whole sky without distortion up to the zenith portion.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.
[0012]
[Means for Solving the Problems]
The outline of the invention disclosed in the present application will be briefly described as follows.
(1) are arranged along a rotating sphere, the 1-dimensional imaging device having a lenticular lens on the imaging device, means for rotating said 1-dimensional image sensor scanning direction of the one-dimensional image sensor as the rotation axis, the And a wide-field video imaging device that develops a round panoramic video into a two-dimensional video.
(2) A one-dimensional image sensor that is arranged along a rotating spherical surface and has a minute lens that collects parallel light for each pixel of the image sensor, and the one-dimensional image with the scanning direction of the one-dimensional image sensor as a rotation axis. And a means for rotating the imaging device, and a wide-field video imaging device that develops a round panoramic video into a two-dimensional video.
( 3 ) The wide-field video imaging device of the means (1) or (2) includes means for rotating the imaging device in synchronism with a frame frequency of a video input device or a monitor device, and continuously panoramic video Is taken.
[0014]
The point of the present invention is that the one-dimensional image pickup device (line sensor) is rotated about the scanning direction of the one-dimensional image pickup device, and an omnidirectional video is picked up as a moving image, and the one-dimensional image pickup device (line sensor). Is arranged along the rotating spherical surface, and a wide-field video imaging device that develops a round panoramic video into a two-dimensional video.
[0015]
Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) according to the present invention.
In all the drawings for explaining the present embodiment, parts having the same function are given the same reference numerals, and repeated explanation thereof is omitted.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Example 1
FIG. 1 is a schematic diagram illustrating a schematic configuration of a wide-field video imaging apparatus according to Embodiment 1 of the present invention. In FIG. 1, 1 is a support part, 2 is a line sensor, 3 is a light receiving part of the line sensor, 4 is a lenticular lens, 5 is a rotation part, 6 is a signal processing part, 7 is a television monitor, and A is a spherical center part. Point B is a spherical surface.
[0017]
As shown in FIG. 1, the wide-field video imaging apparatus of the first embodiment is in a straight line perpendicular to the surface having the same curvature as the spherical surface B centered on the point A of the spherical central portion of the support portion 1. The line sensor 2 is disposed in The line sensor 2 is connected to the rotating unit 5 by the support unit 1, and rotates along the spherical surface B by the rotating unit 5. A readout signal from the line sensor 2 is displayed on the television monitor 7 through a signal processing unit (A / D conversion and frame memory, D / A conversion, etc.) 6.
[0018]
A lenticular lens 4 is disposed on the line sensor 2 with the same curvature as the line sensor 2. FIG. 2 is a cross-sectional view of the line sensor 2 and the lens (a cut surface at CC ′ in FIG. 1). Incident light from the subject is condensed on the light receiving unit 3 of the line sensor 2 by the lenticular lens 4. FIG. 3 shows an enlarged cross-sectional view of the portion D surrounded by a dotted line in FIG. 1 in the transverse direction.
[0019]
In order to drive the line sensor 2 on the time axis, when the scanning is performed from the upper side to the lower side of the center of the rotation axis and the rotation unit 5 rotates at a constant speed, the read signals are received light images at spatially different positions. Will be output one after another. When the signal read from the line sensor 2 is synchronized with the input signal and displayed on a two-dimensional screen such as a television monitor, a panoramic image can be obtained without performing signal processing. FIG. 4 shows the spatial arrangement of the panoramic image at this time. The upper part is the zenith part, the middle part is the horizon part, and the lower part is the underground part. At this time, the resolution in the vertical direction is determined by the number of pixels of the line sensor 2, and the resolution in the horizontal direction is determined by the number of scans of the line sensor 2 during one rotation of the rotating unit 5. For example, if the number of pixels of the line sensor 2 is 1080 pixels and scanning is performed 1920 times during one rotation, the vertical resolution of the image in one rotation is 1080 pixels and the horizontal resolution is 1920 pixels.
[0020]
FIG. 5 shows an example of the writing order and reading order of the frame memory in the signal processing unit. The readout signal from the line sensor 2 is AD-converted, written in the order of W1 to Wm on the frame memory, and read out in the order of R1 to Rn, so that it can be converted into a signal similar to the scanning direction of the television monitor 7. For example, when the rotation unit is rotated 60 times per second, the number of pixels of the line sensor 2 is 1080 pixels, and the number of scans of the line sensor 2 during one rotation is 1920 times, the signal output from the frame memory is 1920 pixels horizontal The vertical 1080 line, 60 frame / second television signal can be displayed as a moving image on the television monitor.
[0021]
(Example 2)
FIG. 6 is a schematic diagram illustrating a schematic configuration of the wide-field video imaging apparatus according to the second embodiment of the present invention.
As shown in FIG. 6, the wide-field imaging device of the second embodiment is configured such that, in the line sensor 2 of the first embodiment, a micro optical lens (on-chip lens) 8 is used instead of the lenticular lens 4. It is arranged on the light receiving part (light receiving element) 3. FIG. 7 shows a cross-sectional view taken along the line EE ′ of FIG. 6, and FIG. 8 shows an enlarged cross-sectional view of the EE ′ part of FIG. With this configuration, the incident light from the subject can be condensed on each light receiving portion (light receiving element) 3 of the line sensor 2 in the same manner as shown in FIGS. By using the on-chip lens 8, the aperture ratio of the sensor light receiving unit can be made higher than that of the lenticular lens.
[0022]
(Example 3)
FIG. 9 is a schematic diagram illustrating a schematic configuration of a wide-field video imaging apparatus according to Embodiment 3 of the present invention.
As shown in FIG. 9, the wide-field video imaging apparatus of the third embodiment need not be limited to only one line sensor 2 arranged on the spherical surface B of FIG. Similarly to the above, it is arranged vertically along the spherical surface.
[0023]
FIG. 9 shows a state where four line sensors are arranged as observed from the zenith portion. The line sensors LS1 to LS4 rotate in the same direction. In this case, since the imaging space is divided into four by the four line sensors LS1 to LS4, in order to obtain the whole sky image, the rotation unit only needs to make a quarter rotation.
[0024]
FIG. 10 shows a state where captured images from the line sensors LS1 to LS4 are displayed on the two-dimensional screen. The difference between the captured video storage time in the third embodiment and the captured video storage time in the first embodiment is 1/60 * 1/1920 in the first embodiment, whereas In the case of Example 3: 1/60 * 1/480.
[0025]
As described above, according to the third embodiment, by synthesizing the spaces imaged by the four line sensors LS1 to LS4, a single panoramic image can be obtained only by a quarter rotation. Can do.
[0026]
At this time, since the rotational speed is reduced to ¼, the scanning speed of each of the line sensors LS1 to LS4 can be reduced to ¼ in order to obtain the same resolution as when the number of line sensors is one. Accordingly, the charge accumulation time (exposure time) of the light receiving portions (light receiving elements) 3 of the line sensors LS1 to LS4 is quadrupled, and the imaging sensitivity can be improved.
[0027]
As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Of course.
[0028]
【The invention's effect】
The effects obtained by the invention disclosed in the present application will be briefly described as follows.
(1) A high-definition and wide-field image can be easily obtained without requiring a high-definition sensor.
(2) Since the captured video has already been panoramicly developed, image conversion processing for developing the panoramic video is not necessary.
(3) There is no image quality deterioration due to interpolation processing at the periphery of the image by panoramic development image processing.
(4) The lens used is small and inexpensive.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a schematic configuration of a wide-field video imaging apparatus according to a first embodiment of the present invention.
2 is a cross-sectional view of a line sensor and a lens taken along line CC ′ in FIG. 1. FIG.
3 is an enlarged cross-sectional view in a transverse direction of a portion D surrounded by a dotted line in FIG.
FIG. 4 is a diagram illustrating a panoramic spatial arrangement when a readout signal from the line sensor according to the first embodiment is displayed on a two-dimensional screen.
FIG. 5 is a diagram illustrating an example of a writing order and a reading order of the frame memory in the signal processing unit according to the first embodiment.
FIG. 6 is a schematic diagram illustrating a schematic configuration of a wide-field video imaging apparatus according to Embodiment 2 of the present invention.
7 is a cross-sectional view taken along the line EE ′ of FIG.
8 is an enlarged cross-sectional view of the EE ′ portion in FIG. 6 in the transverse direction.
FIG. 9 is a schematic diagram showing a schematic configuration of a wide-field video imaging apparatus according to Embodiment 3 of the present invention.
FIG. 10 is a diagram illustrating a state where an image captured by each line sensor according to the third embodiment is displayed on a two-dimensional screen.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Support part 2 ... Line sensor 3 ... Light-receiving part of a line sensor 4 ... Lenticular lens 5 ... Rotating part 6 ... Signal processing part 7 ... Television monitor 8 ... Micro optical lens (on-chip lens)
LS1 to LS4 ... Line sensor A ... Spherical center point B ... Spherical surface

Claims (3)

Are arranged along a rotating sphere, the 1-dimensional imaging device having a lenticular lens on the imaging device,
Means for rotating said 1-dimensional image sensor scanning direction of the one-dimensional image sensor as a rotation axis,
A wide-field video imaging device characterized in that a round panoramic video is developed into a two-dimensional video. Are arranged along a rotating sphere, the 1-dimensional imaging device having a micro lens that condenses the parallel light for each pixel of the image sensor,
Means for rotating said 1-dimensional image sensor scanning direction of the one-dimensional image sensor as a rotation axis,
A wide-field video imaging device characterized in that a round panoramic video is developed into a two-dimensional video. The wide-field video imaging device according to claim 1 or 2, further comprising means for rotating the imaging device in synchronization with a frame frequency of a video input device or a monitor device,
A wide-field video imaging device characterized by continuously imaging a round panoramic video.

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