Source: https://patents.google.com/patent/JP3790371B2/en
Timestamp: 2019-12-16 11:51:31
Document Index: 364491568

Matched Legal Cases: ['Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10']

JP3790371B2 - Stereoscopic image device - Google Patents
Stereoscopic image device Download PDF
JP3790371B2
JP3790371B2 JP28840798A JP28840798A JP3790371B2 JP 3790371 B2 JP3790371 B2 JP 3790371B2 JP 28840798 A JP28840798 A JP 28840798A JP 28840798 A JP28840798 A JP 28840798A JP 3790371 B2 JP3790371 B2 JP 3790371B2
JP28840798A
JP2000122191A (en
智之 三科
春男 星野
1998-10-09 Application filed by 日本放送協会 filed Critical 日本放送協会
1998-10-09 Priority to JP28840798A priority Critical patent/JP3790371B2/en
2000-04-28 Publication of JP2000122191A publication Critical patent/JP2000122191A/en
2006-06-28 Publication of JP3790371B2 publication Critical patent/JP3790371B2/en
The present invention relates to a stereoscopic image device that optically transmits a stereoscopic image, and relates to an optical stereoscopic image device that applies so-called integral photography (IP) technology.
Integral photography is one of the three-dimensional image systems, and uses microlenses such as insect compound eyes.
For example, as shown in FIG. 1, the optical stereoscopic image device applying the integral photography technique has a lens function by having a nonuniform refractive index distribution such as a square characteristic in the radial direction. A plurality of optical fibers (graded index optical fibers) 10 having the same length, the length of which is an integral multiple of one period of the optical path, and the same two-dimensional array (hereinafter referred to as “optical fiber group”) at both ends of the optical fiber. Japanese Patent Application No. 10-117355 discloses a stereoscopic image device that captures, transmits, and displays a stereoscopic image (subject) 11 with the above configuration.
According to the prior invention, if a stereoscopic image can be transmitted over a long distance without increasing the scale of the optical transmission path and without making the light an electrical signal, the optical fiber can be bent. Also, the transmission path can be bent. In addition, a three-dimensional image can be enlarged, reduced, or photomultiplied by inserting an enlargement, reduction, or photomultiplier element at a specific location in the middle of the optical fiber. Therefore, this prior application apparatus can be applied as an endoscope or a borescope for providing a stereoscopic image.
However, in the prior application of Japanese Patent Application No. 10-117355, the reproduced stereoscopic image 12 can be generated only behind the end face of the optical fiber 10 (that is, in the optical fiber group), as shown in FIG. There was a problem to be solved that the image cannot be displayed as an aerial image on the front surface of the optical fiber.
An object of the present invention is to provide a stereoscopic image apparatus that solves the above-described problems and can display a stereoscopic image as an aerial image on the front surface of an optical fiber.
In order to achieve the above-mentioned object, the invention of claim 1 is to form a group of optical fibers having the same length and a plurality of optical fibers having a lens action so as to be two-dimensionally arranged at both ends of the optical fiber. In a stereoscopic image apparatus that captures, transmits, and displays a stereoscopic image, each length of the optical fiber is an odd multiple of a half cycle of an optical path in the optical fiber.
Here, preferably, an optical fiber having a nonuniform refractive index distribution such as a square characteristic in the radial direction is used as the optical fiber.
Preferably, even numbers of the optical fiber groups are used, and the respective optical fiber groups are arranged in series with a predetermined interval therebetween to capture, transmit, and display a stereoscopic image.
Preferably, when parallel light is incident on an optical fiber of the optical fiber group, a reduction optical system, an enlargement optical system, or a rotation optical system is inserted into a surface that forms an image in the optical fiber.
Preferably, when parallel light is incident on the optical fiber of the optical fiber group, a photomultiplier is inserted into a surface that forms an image in the optical fiber.
In the present invention, optical fibers having the same length and a plurality of optical fibers having a lens function so as to have a nonuniform refractive index distribution such as a square characteristic in the radial direction are set so that the length is an odd multiple of a half cycle of the optical path. In addition, since a plurality of optical fiber groups are used so that both ends of the optical fiber are arranged in the same two-dimensional array, a three-dimensional reproduction image can be displayed as an aerial image on the front surface of the optical fiber.
As an example where the refractive index of the optical fiber is high at the center in the radial direction and decreases as it goes to the periphery,
When the light is incident on the optical fiber 10 having the characteristics shown in FIG. 2, since the refractive index is higher at the central portion (axial center portion) in the radial direction, the light meanders and is connected at a specific point as shown in FIG. It has a lens effect. This principle was discovered by D. MARCUSE et al. In 1964, and its details are described in The Bell System Technical Journal. (July, 1964) and the like. Here, the ray matrix of the optical fiber, that is, the relationship between the position and angle of the incident light and the position and angle of the outgoing light can be expressed as the following equation (2).
There is a relationship as shown in FIG.
In the stereoscopic image device of Japanese Patent Application No. 10-117535 that is the invention of the present inventors, the imaging unit and the display unit are connected and integrated, and the length Z 0 of the optical fiber 10 is
As shown in FIG. 4, it is arranged and configured in a two-dimensional manner so that a stereoscopic image can be directly observed on the exit end face of this optical fiber group (optical fiber bundle).
Here, in the above equation (3), the length corresponding to θ = 2π corresponds to one cycle of the optical path in the optical fiber.
For fiber length satisfying the equation (3), from the equation (2), r 1 = r 2, r '1 = r' 2 becomes as shown in Figure 5, the angle of the incident light phi i and the outgoing light beam Have the same angle φ 0 . If this optical fiber is arranged two-dimensionally as shown in FIG. 4, the direction of the light beam from the subject at the entrance end face is reproduced at the exit end face.
Therefore, as shown in FIG. 1, a reproduced image is obtained on the exit end face side at the same distance as the distance from the incident end to the subject and the same size as the subject. In this state, as described above, the reproduced stereoscopic image can be generated only behind the end face of the optical fiber 10, and the stereoscopic image cannot be displayed as an aerial image on the front surface of the optical fiber.
On the other hand, in order to display a stereoscopic image on the front surface of the optical fiber, the length Z 0 of the optical fiber is set.
6, r 1 = −r 2 , r ′ 1 = −r ′ 2 as shown in FIG. 6, and the angle φ i of the incident light beam and the angle φ 0 of the output light beam are opposite in sign and absolute. The values are equal.
Therefore, as shown in FIG. 7, when considering the light beam emitted from the center of the end face of each optical fiber 10, the light beam on the incident side is folded back symmetrically to the incident end face, and the light traveling direction, that is, the outside of the optical fiber 10. At the same distance d 1 from the incident end to the subject 11. That is, a reproduced image 12 is formed at this intersection P.
In this case, unlike the condition of the above formula (3), the light emitted from the entire end face of each optical fiber 10 is output from the virtual condensing point P ′ on the emission end side as shown in FIG. As it is, it progresses with a certain spread. From these facts, the triangle OO 1 O 3 on the incident light side and the triangle P′P 3 P 1 on the outgoing light side are reversely congruent, that is, the triangle O′O 1 O 3 line symmetric with the triangle OO 1 O 3 on the incident light side. It can be seen that the triangle P′P 1 P 3 on the outgoing light side is congruent. Therefore, since the position P of the reconstructed image viewed from the virtual condensing point P ′ is at a distance 2d 1 that is twice the distance from the virtual condensing point P ′ to the exit end of the optical fiber 10, this spread is reproduced. On the surface, it becomes 2D 0 which is twice the spread D 0 of the light beam coming out from the output side end face of one optical fiber, and a blur image is obtained by this spread. However, this blur is not a problem when the end face is small.
Eventually, in this state, the reproduced image 12 is obtained with the same size as that of the subject 11, but since it is viewed from the opposite direction to the subject, the unevenness is reversed. That is, it is possible to obtain an image (reproduced image) with the concavities and convexities reversed on the outside of the exit end face of the optical fiber 10 at the same distance and the same size as the distance between the subject and the entrance end face.
In this state, since the unevenness is reversed, as shown in FIG. 8, it is a feature of the present invention to eliminate the unevenness by using two or even sets of this optical fiber group in series at a certain interval. is there. The certain distance in this case means that the image (first image) formed by the first optical fiber group 10-1 is in front of the input end face of the second optical fiber group 10-2 (that is, FIG. 8). (D 2 is not negative), and the image (second image) formed by the second optical fiber is correct as an aerial image outside the optical fiber end. That is, in the arrangement shown in FIG. 8, since the inversion of the unevenness occurs twice, as a result, the unevenness becomes a correct image, and the first and second fiber groups 10-1 and 10-2 form an aerial image. The second image) is an aerial image.
When parallel light is input to the optical fiber 10A on the incident side, that is, the surface on which the image is formed in the optical fiber 10A, the magnified optical system 21 is inserted to compare the size of the reproduced stereoscopic image with that of the subject. Can be expanded. Similarly, if this magnifying optical system is a reduction optical system, the reproduced stereoscopic image can be reduced.
Examples of these enlargement / reduction optical systems include fiber optic plates (product of Hamamatsu Photonics Co., Ltd.). Even in this case, it is necessary that the total length of the optical fiber of the optical system satisfies the above formula (4).
Further, a stereoscopic image can be rotated by inserting a fiber optical system similar to the fiber optic plate (US: manufactured by INCOM) into the same position instead of the magnifying optical system 21.
Furthermore, by inserting a photomultiplier such as an image intensifier at the same position, it is possible to increase the brightness of the display image or compensate for the decrease in brightness due to transmission loss.
Of course, like the invention described in Japanese Patent Application No. 10-117355 invented by the present inventors, if the optical fiber group can be bent, the transmission line of the present invention can be bent. Become. For example, since each optical fiber itself is flexible, a fixing device that tightens only the both end positions of the optical fiber group, or an adhesive can be attached, or the outside of the optical fiber group can be freely bent, for example, a shape memory alloy, The optical fiber group may be covered with a shape memory resin, lead or copper wire, rubber or soft plastic tube, or the like.
As described above, according to the present invention, a plurality of optical fibers having the same length and having a lens action are made into an optical fiber group configured so as to have the same two-dimensional arrangement at both ends of the optical fiber, thereby providing a stereoscopic image. In a stereoscopic image device that captures, transmits, and displays images, the length of the optical fiber is an odd multiple of a half cycle of the optical path in the optical fiber, so that a stereoscopic image can be transmitted over a long distance without using light as an electrical signal. The resulting stereoscopic image is an aerial image located outside the end face of the optical fiber.
Further, according to the present invention, the inversion of the unevenness can be eliminated by using two sets of the optical fiber groups in series with a certain interval.
According to the present invention, a stereoscopic image can be enlarged, reduced, or rotated by inserting an optical element for enlargement, reduction, or rotation at a specific location in the middle of the optical fiber. Further, by inserting a photomultiplier element, it is possible to increase the brightness of the display image or to compensate for the decrease in brightness due to transmission loss.
It is also possible to bend the transmission line of the present invention.
Therefore, the stereoscopic image device according to the present invention can be applied as an endoscope or a borescope that provides a stereoscopic image.
FIG. 1 is an optical path diagram showing a state of stereoscopic image reproduction described in Japanese Patent Application No. 10-117355 of a prior application.
FIG. 2 is an optical path diagram showing an operation principle diagram of an optical fiber.
FIG. 3 is an optical path diagram showing incident light and outgoing light of an optical fiber.
FIG. 4 is a conceptual diagram showing an optical fiber group in which basic unit optical fibers are two-dimensionally arranged.
FIG. 5 is an optical path diagram showing an example of an optical fiber length (θ = 4π) described in Japanese Patent Application No. 10-117355.
FIG. 6 is an optical path diagram showing a relationship between incident light rays and outgoing light rays in the stereoscopic image apparatus according to the embodiment of the present invention.
FIG. 7 is an optical path diagram showing a relationship between a subject and a reproduced image by one optical fiber group in the stereoscopic image apparatus according to the embodiment of the present invention.
FIG. 8 is an optical path diagram illustrating a relationship between a subject and a reproduced image by two optical fiber groups in the stereoscopic image device according to the embodiment of the present invention.
FIG. 9 is a configuration diagram showing enlargement of a reproduced stereoscopic image in the stereoscopic image device according to the embodiment of the present invention.
DESCRIPTION OF SYMBOLS 10 Optical fiber 10-1, 10-2 Optical fiber group 11 Subject 12 Reproduction image 21 Magnification optical system
In a stereoscopic image device that captures, transmits, and displays a stereoscopic image by forming a plurality of optical fibers of the same length having a lens action into an optical fiber group configured so as to be two-dimensionally arranged at both ends of the optical fiber,
A stereoscopic image apparatus, wherein each length of the optical fiber is an odd multiple of a half cycle of an optical path in the optical fiber.
The stereoscopic image device according to claim 1, wherein an optical fiber having a nonuniform refractive index distribution such as a square characteristic in a radial direction is used as the optical fiber.
3. The stereoscopic image device according to claim 1, wherein even numbers of the optical fiber groups are used, and each optical fiber group is arranged in series with a predetermined interval therebetween to capture, transmit, and display a stereoscopic image.
4. A reduction optical system, an enlargement optical system, or a rotation optical system is inserted into a surface that forms an image in the optical fiber when parallel light enters the optical fiber of the optical fiber group. The stereoscopic image device according to any one of the above.
4. The three-dimensional object according to claim 1, wherein a photomultiplier is inserted into a surface that forms an image in the optical fiber when parallel light is incident on the optical fiber of the optical fiber group. 5. Imaging device.
JP28840798A 1998-10-09 1998-10-09 Stereoscopic image device Expired - Fee Related JP3790371B2 (en)
JP28840798A JP3790371B2 (en) 1998-10-09 1998-10-09 Stereoscopic image device
US09/414,542 US6301416B1 (en) 1998-10-09 1999-10-08 Optical three-dimensional imaging device which uses an integral photography technique
JP2000122191A JP2000122191A (en) 2000-04-28
JP3790371B2 true JP3790371B2 (en) 2006-06-28
ID=17729818
JP28840798A Expired - Fee Related JP3790371B2 (en) 1998-10-09 1998-10-09 Stereoscopic image device
US (1) US6301416B1 (en)
JP (1) JP3790371B2 (en)
JP5374021B2 (en) * 2005-01-19 2013-12-25 パナソニック株式会社 Refractive index distribution lens, manufacturing method of gradient index lens, stereoscopic image pickup device, and stereoscopic image reproduction device
JP6450073B2 (en) * 2014-01-29 2019-01-09 日本放送協会 Lens array
1998-10-09 JP JP28840798A patent/JP3790371B2/en not_active Expired - Fee Related
1999-10-08 US US09/414,542 patent/US6301416B1/en not_active Expired - Lifetime
US6301416B1 (en) 2001-10-09
JP2000122191A (en) 2000-04-28
JP4995732B2 (en) 2012-08-08 System and method for near-focus ray expansion in a display device