Optical system for holographic video camera

FIELD: physics.

SUBSTANCE: optical system for a holographic video camera includes an optical waveguide with an input holographic element on its surface, a lens, a visible radiation detector, an infrared radiation detector and a photoelectric converter connected to said detectors. The input holographic element is configured to split input radiation into visible and infrared parts. The optical waveguide is configured to transfer the visible part of radiation towards the visible radiation detector and the infrared part towards the infrared radiation detector. The lens is configured to form an image of an object through the optical waveguide and the holographic element on the detector. The photoelectric converter is configured to determine the phase difference between output signals, which are radiation intensity distribution in images obtained from visible and infrared radiation detectors.

EFFECT: possibility of using a single lens for infrared and visible radiation, possibility of remote formation of a depth map in order to form a pseudo three-dimensional image.

9 cl, 6 dwg

The invention relates to technology design video cameras high resolution, in particular to the creation of optical systems for holographic cameras in low-light conditions.

The majority of known optical systems for cameras, which allow to obtain high-quality color images in low-light conditions or to build more suited to the image based on the combination of two separate channels for visible and infrared radiation, respectively. Many of these optical systems use complex lenses in which part of the lens is used only for focusing visible light, and the other part is only for focusing infrared radiation. Other modifications of the optical systems for cameras in difficult conditions, based on a single lens system and reflecting mirrors.

The prior art camera (see laid out in the application for U.S. patent No. 20100066854) [1], is able to create a depth map to build pseudostreaming images, including the formation of the image having the first depth of field (DOF) for one or more of the first color and the second depth of field (DOF), smaller than the first, for one or more second colors. the system forming the image may include an iris aperture with the first aperture for the first color or colors and the second aperture, greater than the first, for the second color or colors. The first aperture can be defined outer dark ring (1)and the second color internal ring (2). The inner ring (2) blocks of the first color(s) and transmits the second color(s). The image generated by the first ring, sharper, and its sharpness can be reproduced in the processing of other images.

The prior art optical system (see U.S. patent No. 6870690) [2], based on the use of a single lens or optical system to image in two different optical bands. Single lens or optical system used for image generated in two different spectral ranges, for example in the range of visible and infrared light. Dual band singlet formed from the first, larger optical element used for the first spectral range. The smaller element is used to work with the second spectral range and within the aperture, cutting it from the first component, forming, thus, a dual band singlet, which can work on two different wavelengths.

In published U.S. patent No. 5212375 [3] proposed a system for determining the focus of the digital camera based on the holographic beam splitter light. In this, closest to the proposed invented the Yu, the system is provided by the presence of at least one holographic element located on an optical path of the photographic lens; this element is used to separate the radiation into several different beams, one of which gets on depicting the detector of the camera, and at least one other beam hits the detector to focus.

A holographic optical element (hereinafter referred to as - ett) depending on the diffraction function of the hologram is used as a lens, a mirror, a beam-splitting prism, etc. as hoe works only for recording picture interference light beams in a thin plane, the structure and the work principle is very simple, namely two beams of radiation passing through various optical systems, diluted in different directions single hoe, located closer to the object than the primary image plane, for forming two images on the detectors. Focusing is carried out by determining the phase difference between the output signals from the detectors. This allows you to get rid of several additional elements, such as field aperture, condenser lens, mirror, finishing aperture. This simplifies the design of the camera and allows you to make it more compact is Noah.

It should be noted that hoe, which can be formed on various plastics, cheap and simple in structure. Thus, the cheapness and simplicity of structure single hoe allow its use for the separation of a light beam on the photographic system and the focusing system, and allows you to focus in photography.

The problem to which the invention is directed is to provide the camera more compact, simple to manufacture and easy optical system, in which for visible light and infrared light, it is possible to use a single lens, and the depth map to create pseudostreaming image can be generated remotely.

The technical result is achieved due to the development of an improved optical system for holographic video cameras, this system includes:

at least one optical waveguide with at least one introduces holographic element on its surface;

at least one lens;

detector for visible light;

detector for infrared radiation;

- photoelectric Converter connected to the detector for visible radiation and a detector for infrared radiation;

moreover, the profile is entrusted characteristics of this design are that

- introducing the holographic element configured to split the incoming radiation in the visible and infrared parts;

optical waveguide is configured to transfer the visible part of the radiation in the direction of the detector for the visible radiation and infrared radiation in the direction of the detector for infrared radiation;

lens configured to form an image of the object through the optical waveguide and the holographic element detector;

- photoelectric Converter is implemented with the ability to capture the difference in phase between the output signals representing the intensity distribution of the radiation images obtained with detectors for visible and infrared radiation.

The essence of the invention is further illustrated with engaging graphics, which provides:

Figure 1. The structure of the claimed invention (introducing a holographic element and a detector for infrared radiation are located directly on one of the optical elements of the lens)

Elements:

10 - General lens

20 lens for visible light

30 detector for visible light

50 detector for infrared radiation

60 optical waveguide

80 - introducing the holographic element.

Figure 2. Structure the tour of the claimed invention (electrically controlled to introduce a holographic element)

Elements:

10 - General lens

20 lens for visible light

30 detector for visible light

50 detector for infrared radiation

60 optical waveguide

80 - introducing the holographic element

140 - control module diffraction efficiency.

Figure 3. The structure of the claimed invention (introducing the holographic element is located directly on one of the optical elements of the lens)

Elements:

10 - General lens

20 lens for visible light

30 detector for visible light

40 lens for infrared radiation

50 detector for infrared radiation

80 - introducing the holographic element.

Figure 4. The structure of the claimed invention (introducing the holographic element is located directly on one of the optical elements of the lens and the detector for infrared radiation has a high resolution)

Elements:

10 - General lens

20 lens for visible light

30 detector for visible light

40 lens for infrared radiation

50 detector for infrared radiation

80 - introducing the holographic element.

Figure 5. The structure of the claimed invention (additional infrared illumination)

Elements:

10 - General lens

20 lens for apparent from the teachings

30 detector for visible light

40 lens for infrared radiation

50 detector for infrared radiation

80 - introducing the holographic element

120 - holographic structured illumination element

130 - infrared laser.

6. The structure of the claimed invention (with reflective introducing holographic element)

Elements:

10 - General lens

20 lens for visible light

30 detector for visible light

40 lens for infrared radiation

50 detector for infrared radiation

150 - reflecting introducing the holographic element.

Holographic video camera comprises: an optical waveguide with a holographic optical elements, deposited on its surface, which provide separation of the incoming radiation in the visible and infrared parts; General optical lens, transmitting the input light from the input system to the optical waveguide; lens for visible light that forms the image on the detector for visible light, and a lens for infrared radiation, which forms an image on the detector for infrared radiation. Holographic optical elements are selected reflective or transmissive with electrically or optically controlled diffraction the th efficiency and selectivity.

General lens 10 projects the input image in a plane that is transmissive or reflective, introducing holographic element 80. Depending on the design introduces holographic elements, for transmitting or reflecting the appropriate wavelength, include, for example, on the surface of the optical waveguide 60 (Figure 1). Depending on the wavelength of introducing holographic elements 80 enter the input radiation into the optical waveguide.

The preferred design is to have misleading topographic element 80 on the surfaces of the lens (Figure 1). In this case there is no need to use a special waveguide Board, its role is carried out directly one of the lenses of the lens. For visible and infrared radiation are the elements of the lens. The detector 50 for infrared radiation can also be located directly on the surface of the overall lens 10.

As misleading holographic element 80 can be used hologram controlled efficiency (for example, electrically controlled hologram) (Figure 2). In this case, the degree of refraction of radiation is controlled by a special module 140 controls the diffraction efficiency.

An example implementation of an optical system in a holographic camera etc is presented in figure 1. Holographic video camera includes an optical waveguide 60, which introduces a holographic element 80, which divides the input radiation that has passed through the common lens 10, the visible and infrared parts. The lens 20 for visible light focuses the visible portion of the input radiation to the detector 30 for visible light, while the total lens 10 focuses the infrared part of the input radiation to the detector 50 for infrared radiation.

The incoming radiation, which has in its composition the visible and infrared components, pass through a common lens 10 and arrives at the optical waveguide 60 with introducing holographic element 80 on its surface. Introducing the holographic element 80 has zero optical power for visible light, which passes through it, and focused by lens 20 for visible radiation hits the detector 30 for visible radiation. The infrared radiation is reflected from introducing holographic element 80. Propagating in the optical waveguide 60, the infrared radiation falls on the detector 50 for infrared radiation.

Introducing the holographic element 80 is located on the surface of one lens of the lens 10 so that the incoming radiation dirigeret on it, causing the waveguide modes inside the lens, and the radiation of a certain length in the wave, in this case, the infrared radiation range, separated from the incoming radiation and detected by detector 50 for infrared radiation and is not detected by the detector 30 to visible radiation.

The scheme allows the use of different types of misleading holographic element is a reflective type, a transmissive type or a combination of both.

Figure 2 shows an alternative system. The system works as follows: incident light diffugere on introducing holographic element 80, which is made in the form of electrically controlled holographic element and is connected to the module 140 controls the diffraction efficiency. This solution allows to increase the separation efficiency of infrared radiation. While specified misleading holographic element 80 may also be made in the form of a set of electrically controlled holograms, each of which can run in a separate spectral range. Thus, the module 140 controls the diffraction efficiency can select the desired spectral range.

Figure 3 shows another variant of the system, where high quality infrared channel is achieved by using special image processing.

Shown in Figure 4 system variant differs in that it contains infraclass the th channel with the high-resolution detector and image quality, identical visible channel.

Figure 5 shows a variant of the system with illuminator to create a depth map for pseudostreaming image. The illuminator includes an infrared laser 130 and holographic structured element 120 of the backlight, which forms a strip in the plane of the object. The illuminator illuminates the object through the holographic structured lighting unit, and the offset of the image strips on the detector for infrared radiation determines the depth map of the object.

Figure 6 shows a variant of the system, where to improve the efficiency and selectivity of the infrared channel is used to introduce a holographic reflecting element type.

All described variants of the system are connected to form a single inventive concept and are designed to solve the same task.

From the above examples it is seen that there are various ways of implementing the basic concept embodied in the claimed invention.

In particular, it makes sense that in the inventive optical system, the optical waveguide was performed placed on its surface detector of infrared radiation, and the lens would be made in the form of lens for visible light capable of forming an object image through the optical waveguide, and introduced a holographic element detector for visible irradiation the Oia.

It also makes sense that in the inventive optical system, the optical waveguide was performed by a common lens, configured to transfer the visible part of the radiation in the direction of the lens for visible light and imaging the object on the detector for infrared radiation.

In another implementation it is proposed that the total lens was equipped with introducing holographic element on its last surface, and this lens performs with the possibility of transferring the visible part of the radiation in the direction of the lens for visible light and infrared radiation in the direction of the lens for infrared radiation.

Another variant provides that the inventive optical system further includes:

- holographic structured illumination element,

- infrared laser, and

- holographic structured lighting unit has a capability of forming a strip in the plane of the object;

- infrared laser configured to illuminate the object through the holographic structured illumination element.

You should pay attention to the fact that introducing the holographic element can be implemented in various ways, for example it can be made the type of a reflecting element, or is designed as an electrically controlled topographic element and is connected to the control module diffraction efficiency, or made in the form of a set of electrically controlled holographic elements, each of which is designed with the ability to work in a separate spectral range.

In addition, in some embodiments of the inventive optical system, the detector for the visible radiation and a detector for infrared radiation can be made in the form of a matrix.

It should also be noted that since the zero order transmitted through the hoe radiation gives a small chromatic aberration, it is desirable that the photographic optical system had a small supply of chromatic aberration.

The inventive optical system can be effectively used in cameras, providing high quality colour images in low light conditions.

1. The optical system of the holographic camera, which includes,
at least one optical waveguide with at least one introduces holographic element on its surface;
at least one lens;
detector for visible light;
detector for infrared radiation;
- photoelectric Converter connected to the detector for visible radiation and a detector for infrared radiation, characterized in that
- introducing the holographic element is designed with the capability, the capacity of the separation of the incoming radiation in the visible and infrared parts;
optical waveguide is configured to transfer the visible part of the radiation in the direction of the detector for the visible radiation and infrared radiation in the direction of the detector for infrared radiation;
lens configured to form images of the object through the optical waveguide and the holographic element detector;
- photoelectric Converter is implemented with the possibility of fixing the difference in phase between the output signals representing the intensity distribution of the radiation images obtained with detectors for visible and infrared radiation.

2. The optical system according to claim 1, characterized in that the optical waveguide is performed with a detector of infrared radiation on its surface, and the lens is made in the form of a lens for visible light capable of forming an object image through the optical waveguide, and introduced a holographic element detector for visible light.

3. The optical system according to claim 2, characterized in that the optical waveguide takes the overall lens, configured to transfer the visible part of the radiation in the direction of the lens for visible light and imaging the object on the detector for infrared radiation.

4. The optical system according to claim 3, distinguishing the I, what are the common lens is to introduce a holographic element on its last surface and configured to transfer the visible part of the radiation in the direction of the lens for visible light and infrared radiation in the direction of the lens for infrared radiation.

5. The optical system according to claim 4, characterized in that it further includes: holographic structured lighting unit, an infrared laser and holographic structured lighting unit has a capability of forming a strip in the plane of the object; an infrared laser configured to illuminate the object through the holographic structured illumination element.

6. The optical system according to claim 2, wherein introducing the holographic element is made by reflecting type.

7. The optical system according to claim 2, wherein introducing the holographic element is designed as an electrically controlled topographic element and is connected to the control module diffraction efficiency.

8. The optical system according to claim 2, wherein introducing the holographic element is designed in the form of a set of electrically controlled holographic elements, each of which is designed with the ability to work in a separate spectral range.

9. The optical system is as according to any one of claims 1 to 3, characterized in that the detector for the visible radiation and a detector for infrared radiation in the form of matrices.