JP2014074704A - Composite optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image capturing system for flying objects having an optical system that allows various sensors to be provided along optical axes thereof and a communication system for transmitting/receiving data and control commands, which are combined into a mechanically and optically simple and compact configuration.SOLUTION: A composite optical system has a beam splitter which splits multi-wavelength image that enters the beam splitter through an optical system into a P-polarized light component and an S-polarized light component with a predetermined intensity ratio or in accordance with different wavelength regions. One of the split image components is reflected by a reflective mirror, which is located at a focal position and is orthogonal to a main optical axis, and re-enters the beam splitter to be re-split and guided to the next optical system.

Description

  The present invention relates to a compound optical system that distributes an incident image to a plurality of image receiving cameras.

  Thanks to the remarkable development of various image sensors and optical sensors, more advanced information analysis is possible not only in the consumer field but also in the scientific field by digitally processing optical image information captured by the camera.

  In the fusion field of optical technology and digital technology, in many cases, it has been used for recording and reproducing image data captured like a digital camera as it is, but by introducing a more analytical optical mechanism, Separating only light of a specific wavelength in the incident image and converting it into digital data, or dividing the image into multiple parts, and using digital technology to perform each optical analysis and add it to the image information Has been done.

  In recent years, not only in the field of medical close-up, but also in the environmental field, aerospace field, disaster prevention field, etc. There is an increasing demand for using and analyzing sensing information in the invisible light region such as infrared rays and two-dimensional data of the spectral spectrum by linking the image information in the light region.

  For this reason, a multi-wavelength image incident through a lens system such as a telescope or a reflective optical system is mainly divided into a plurality of parts, and optical analysis and image sensing according to the purpose are combined for each divided image plane. The mechanisms and devices of the optical system and sensor system are complicated.

  Sensing data acquired by mounting on such a flying object is stored in a storage device, but it can be stored from a flying object that does not return to the ground in principle, such as a huge amount of data storage and real-time observability. Due to the demand for data acquisition, a data communication system for transmitting stored data or real-time information to a receiving base has to be provided, and the mechanism system is required to be compact.

  On the other hand, a technique is known in which a sensed image is divided into a plurality of images by an optical mechanism, for example, a slit-mirror mechanism, a deflection beam splitter, or the like, by a more compact mechanism (for example, Patent Documents). 1 or Patent Document 2).

  JP 2000-36793 A   JP 2012-98050 A

  In the known technique of Patent Document 1, a mirror (reflection area) is formed so as to obliquely cross the optical axis incident from the lens system, and a slit portion as a light transmission area is formed in the mirror, A two-dimensional image sensor is arranged on the extension optical axis of the mirror reflection system, and a spectral sensing device is arranged on the extension of the slit transmission optical axis.

  As a result, the two-dimensional image data obtained from the mirror reflection system and the spectral data obtained from the slit transmission system can be linked with a compact apparatus configuration. In this case, the real image of the slit portion is displayed in black, and the image for that portion is missing. For this reason, the image information of the reflection system of the slit-mirror is inevitably accompanied by missing data in the slit portion even when the image is divided and other sensing is performed thereafter.

  On the other hand, the known technique of Patent Document 2 is a communication system using laser light, but a central rhythm that is a deflecting beam splitter (prism type) and an auxiliary prism are bonded and divided into a plurality of optical axis systems. It has become a thing.

  Although it is noticed that the optical system for receiving laser light and the optical system for transmitting laser light are the same, there is no disclosure of the technical idea of split sensing of observation image information, and there are many other than laser transmitting and receiving systems. For the divisional sensing of the wavelength image, another optical system mechanism has to be provided.

  For large amounts of data transmitted from satellites, when using radio waves, frequency bands must be allocated in a realistic manner in accordance with international rules. There is a limit.

  For this reason, although it is necessary to simultaneously realize the optical communication system disclosed in Patent Document 2 and a sensing system for a multi-wavelength image incident through a lens system such as a telescope or a reflective optical system, with Patent Document 1, In the disclosed technology, since the multi-wavelength image incident through a lens system such as a telescope or a reflection optical system is immediately lost by the slit-mirror mechanism, the image of the slit portion is lost. It has not been possible to realize a composite optical system capable of performing a plurality of image sensing and further combining those optical communications.

  The imaging system of a flying object such as an observation satellite has an optical system that can arrange a plurality of various optical sensors on a divided optical path according to the purpose, and a communication system for sending and receiving sensing data and control commands. Although it is required to realize an optical equipment configuration that is as simple and compact as possible and easy to set up, it is difficult in the prior art to compose a dedicated optical system for each.

  The inventor of the present application has conducted intensive research to overcome the above-mentioned problems, and invented a complex optical system that can distribute image information in a complicated manner with a simple configuration and at the same time easily add an optical system for laser light communication. It came to do.

  The central technical idea of the present invention is that it is reflected by a reflection mirror arranged at the focal position of either the P-polarized light or the S-polarized optical axis that is split by the beam splitter, and then enters the beam splitter again, and further splits. As described above, the front, rear, left and right four surfaces of one beam splitter having a cubic or rectangular parallelepiped shape can be used for light incident and reflection.

  That is, the invention of claim 1 of the present application is a composite optical system that distributes a multi-wavelength image incident through a lens system or a reflective optical system to a plurality of optical sensors, and the incident multi-wavelength image is converted into P-polarized light by a beam splitter. One of the divided image planes is divided by a reflection mirror that is perpendicular to the main optical axis arranged at the focal position. Then, the light is again incident on the beam splitter, is divided again according to the above characteristics of the beam splitter, and propagates to the next optical system.

  According to a second aspect of the present invention, the reflecting mirror is a half mirror having a predetermined transmission reflectance in the intensity or wavelength region with respect to an incident multi-wavelength image. System.

  According to a third aspect of the present invention, a slit is formed in a predetermined portion of the reflection mirror, and image information transmitted through the slit of the divided image surface is transmitted to an optical sensor installed on the back surface side of the total reflection mirror. The composite optical system according to claim 1, wherein the composite optical system is introduced.

  The invention of claim 4 is characterized in that a slit is individually arranged for each divided image divided by the beam splitter, and a slit image is individually obtained from each divided image. Item 4. The composite optical system according to Item 3.

  The invention according to claim 5 is characterized in that a laser oscillator and a light receiving sensor are further arranged for extending the optical axis of the lens system and the reflection optical system, and the laser is transmitted and received through the same optical system as the multi-wavelength image distribution. The composite optical system according to any one of claims 1 to 4.

  According to a sixth aspect of the present invention, the optical sensor arranged in the optical axis extension for each divided image divided by the beam splitter is either a visible light two-dimensional image sensor or an invisible light two-dimensional image sensor, and the slit 6. The composite according to claim 1, wherein the optical sensor arranged for extending the optical axis of the light is either a linear image sensor or a spectroscopic sensor having an imaging optical system. It is an optical system.

  The invention of claim 7 is characterized in that the reflection wavelength characteristic of the reflection mirror is adjusted by using a different metal material for the material of the reflection mirror installed in the beam splitter. It is a compound optical system.

  According to an eighth aspect of the present invention, the chromatic aberration generated in the beam splitter is corrected using an optical system that corrects chromatic aberration or the like for an image incident on the beam splitter. A composite optical system according to any one of the above.

  The invention according to claim 9 is characterized in that a lens system or a reflection optical system is finely adjusted mechanically or optically to finely adjust an incident angle or an emission angle of light. A compound optical system according to claim 1.

  The invention according to claim 10 is the composite optical system according to any one of claims 1 to 9, further comprising a temperature sensor and a heat source for temperature control in order to stabilize optical characteristics. is there.

  Further, the inventor of the present application can realize the composite optical system according to any one of claims 1 to 10 centering on a very compact optical configuration. The present inventors also found that application to a telescope that performs observation is very suitable, and invented a remote telescope equipped with the composite optical system of the present application.

  That is, the invention of claim 11 of the present application is a telescope that carries the flight observation in the sky or space by mounting the composite optical system according to any one of claims 1 to 10, and is an image that has passed through a beam splitter. A remote control equipped with a composite optical system characterized in that at least two types of optical observation information are converted into digital information and stored in a storage device, and the stored observation information is transferred to a ground base by communication means Telescope.

  The invention of claim 12 is characterized in that digital information processing, storage in a storage device, and transmission of stored information are performed remotely from a ground base by laser communication or radio wave communication. 11 is a remote telescope equipped with the composite optical system according to 11.

  The invention of claim 13 is a remote telescope that performs communication using visible light or invisible infrared light as light used for laser communication, and the light intensity on the ground is weak enough not to damage the human organs. It is a light, It is a remote telescope which mounts the compound optical system in any one of Claim 11 or Claim 12.

  The invention of claim 14 is characterized in that a filter or shutter for blocking or attenuating light other than a specific wavelength of the light source used for the communication means from the ground is arranged in front of the light receiving sensor. A remote telescope equipped with any one of the composite optical systems.

  The invention of claim 15 is equipped with a sensor for detecting the position of a light source of a specific wavelength installed on the ground, and can emit laser communication light in the vicinity of the light source based on communication from the ground. Or it is a remote telescope which mounts the compound optical system in any one of Claim 14.

  According to a sixteenth aspect of the present invention, an incident light capturing angle, an apparatus temperature, and the like are automatically controlled by a mounted computer. Scope.

  The invention of claim 17 further comprises a spatial light modulator for automatically correcting distortion of an observed image caused by a temperature difference in the atmosphere or space environment. A remote telescope equipped with the composite optical system described in 1.

  According to the present invention, by combining the beam splitter and the reflection mirror with an easy configuration, the image light by one beam splitter is divided into multiple parts, and the function of the reflection mirror is provided to separate specific wavelengths and to perform spectroscopic analysis. A complex optical analysis system such as sensing can be realized with a simple optical system configuration.

  At the same time, since the optical system and the reflection system of the present invention can be used for transmission / reception such as laser light communication using the same configuration, observation data can be appropriately transmitted to a remote receiving base. As the two-dimensional system data, a large amount of sensing data acquired in real time or at short time intervals can be efficiently transmitted.

  Furthermore, due to the above-described effects of the present invention, for a flying object with significant spatial restrictions, such as a small artificial satellite, the observation equipment configuration can be simplified and miniaturized, and at the same time, an optical communication system for realizing mass data communication. Devices can also be combined together.

  It is the figure which showed the optical system of invention of Claim 1 of this application.   It is the figure which showed the optical system of invention of Claim 3 of this application.

  The invention of claim 1 will be described with reference to FIG. A multi-wavelength image that has entered through a lens system or a reflective optical system, for example, image light that has entered through a reflecting telescope, is first divided into a P-polarized light and an S-polarized light at a predetermined intensity ratio by a beam splitter, or divided into different wavelength regions.

  At this time, the optical system in front of the beam splitter can be arbitrarily configured as long as the total light flux of the image light is incident on the beam splitter.

  A beam splitter is an optical device that divides a light beam into two, and transmits a part of the incident light beam (P-polarized light) and reflects a part (S-polarized light). This is a general apparatus having a simple configuration that can divide the intensity and polarization-divide the wavelength region etc. by coating the bonding surface.

  In the present application, the shape (for example, cube type, plate type, etc.), material, spectral angle (usually 90 degrees) of the beam splitter, and functional coding on the prism joint surface are not specified or limited as arbitrary design items.

  In the present application, a reflection mirror orthogonal to the main optical axis is disposed at the focal position of P-polarized light or reflected S-polarized light transmitted through the beam splitter, and the light beam reflected by the mirror reaches the reflective polarization plane of the beam splitter. It arrives through the same optical path and is further reflected or transmitted according to the characteristics of the beam splitter at an angle of 180 degrees with the S-polarization direction of the incident image from the optical system.

  The reflection mirror may be separated from the beam splitter or may be in close contact with the beam splitter. The mirror is in close contact with the beam splitter. A metal mirror is deposited on the prism end face of the beam splitter (vacuum deposition) and the metal mirror coating is precisely applied to form an integrated mirror surface. Can be further simplified.

  Further, it is possible to prepare a reflection mirror in which the wavelength characteristic of the reflected light beam is selected by selecting the material of the mirror. As in the invention of claim 2 of the present application, for example, a half-wavelength transmission type half mirror such as a hot mirror or a cold mirror with a dielectric multilayer coating is formed, or a reflection mirror as in the invention of claim 7 of the present application. By selecting the material metal (for example, aluminum, gold, platinum, silicon, rhodium, etc.), the reflection wavelength characteristics (reflection and absorption) of the mirror can be adjusted, so that the function of the reflection mirror itself can be achieved.

  By combining the beam splitter and the reflecting mirror of the present invention, in addition to the splitting characteristics of the beam splitter, the light flux that is transmitted or reflected is reflected by the mirror, and the speed of light that is further transmitted through the beam splitter. The transmitted light speed can be divided according to the intensity or wavelength according to the purpose, and the optical axis can also be extended 180 degrees opposite to the S-polarization direction of the beam splitter.

  For example, it is possible to make all the cubic end faces facing the reflection polarization plane of the beam splitter as end faces for both incident and emission of light beams, and various sensing mechanisms or optical transmission / reception (laser communication etc.) for each optical axis extension It is possible to arrange a mechanism (the invention of claim 5), and it is possible to construct a multifunctional composite optical system centered on one beam splitter.

  In the optical system of the beam splitter-reflecting mirror system of the invention of claim 1 of the present application, as in the invention of claim 3, by simultaneously forming a slit on the reflecting mirror surface, the slit transmission image light is transmitted to the back surface of the reflecting mirror. It is possible to sense by introducing it into an optical sensor installed on the side.

  In addition, as in the fourth aspect of the present invention, it is possible to individually provide slit image light from each divided image by arranging a slit for each divided image light divided by the beam splitter.

  Naturally, in this case, depending on the purpose, the slit may be formed not only on the reflecting mirror of the invention of claim 3 but also on the end face or a light shielding slit provided with a coating having an antireflection characteristic.

  In contrast to the above-described inventions according to claims 1 to 4, according to the invention of claim 6, the purpose of sensing such as a two-dimensional image sensor, a linear image sensor, and a spectroscopic sensor can be used to extend the optical axis of the divided image light. Since it can be configured with different optical sensors, various observation data of the imaging data system and optical analysis data system can be obtained by relating each other's data with an extremely simple optical and mechanical configuration. can do.

  In the known technique disclosed in Patent Document 2, since the slit mirror is formed on the reflection surface of the beam splitter, as described above, in the subsequent sensing on the optical path, the image light in the slit portion remains missing. Therefore, it is difficult to realize a free and diverse composite optical system of an imaging-optical analysis system as in the present invention.

  In this document, the information on the missing image light in the slit portion can be corrected by embedding (pasting) the image corresponding to the missing portion captured at different times, but it is corrected as simple image information. However, in strict two-dimensional sensing (for example, invisible image sensing such as infrared rays), there is a problem that data consistency between a missing part and other parts due to a time difference cannot be achieved.

  On the other hand, in the present invention, not only the incident light from the front but also the reflected light of the mirror is incident from the back surface of the beam splitter, and further splits it into a plurality of light flux systems. Since each reflection or transmission and slit transmission can be adjusted with respect to the characteristics of the reflection mirror by the material or slitting method, various optical sensing that has not been possible in the past is possible.

  In particular, bonding or coating a reflecting mirror on the end face of the beam splitter to integrate the beam splitter and the reflecting mirror is extremely effective for simplifying and reducing the size of the composite optical system of the present application.

  The beam splitter of the present application is assumed to be a cubic type or a plate type with a single reflection deflection surface. However, when sufficient intensity of the multi-wavelength image light incident from the observation optical system is secured, two or more A beam splitter can be bonded and integrated in series (in the direction of transmitted light) and further divided into a plurality of image light beams.

  At that time, the reflected light (S-polarized light) directions of the respective beam splitters can be made the same, and the respective S-polarized axes can be rotated by 90 degrees, 180 degrees, and 270 degrees.

  Even in the case of a combined beam splitter, a reflection mirror is formed or arranged at the focal position (region) of the image light continuously on the end face of the combined beam splitter and is incident on the beam splitter again. Both cases are included in the scope of the present invention.

  The composite optical system according to the present invention is naturally provided with an optical adjustment / correction mechanism as in the inventions of claims 8 to 10. These adjustment / correction mechanisms may use known techniques.

  Next, the composite optical system according to claim 5 of the present application further combines reception and transmission of laser light. A laser oscillator and a light receiving sensor are further arranged on the optical axis extension of the lens system and the reflection optical system, so that the laser can be transmitted and received through the same optical system as the multi-wavelength image distribution.

  In the present invention, the same configuration of the optical system and the reflection system for observation is used for laser transmission / reception, and is used as a communication means with the ground base, so that the apparatus configuration is extremely simple and small. As in the invention of Item 12, a small remote space telescope (observation satellite) can be realized. Naturally, the remote telescope of the present invention is equipped with a computer for control.

  For example, when the remote telescope of the present invention images, for example, the ground surface, performs multi-faceted sensing of the multi-wavelength image, and transmits a huge amount of data from outer space to a ground base by laser communication, claim 13. As in this invention, when performing communication using visible light or invisible infrared light, it is desirable that the light intensity on the ground be weak enough that the human organs are not damaged.

  In the case of a remote space telescope, there is a possibility that a communication laser, multi-wavelength image light, and laser light emitted by another person may enter the optical path to the laser receiver. There is a risk of trouble occurring. For this reason, in the invention of claim 14, a filter or shutter for blocking or attenuating light other than a specific wavelength of the light source is disposed in front of the light receiving sensor, and only the intended communication laser is received.

  Furthermore, in the remote telescope of the invention of claim 15, in order to specify the position of the base on the ground, a sensor for detecting the position of the light source having a specific wavelength installed on the ground is mounted on the composite optical system, and communication from the ground is performed. Based on the above, it is possible to emit laser communication light from the remote telescope side in the vicinity of the light source after identifying the base, not only for data communication but also for grasping the position of the ground base by radio communication Laser light communication can be used.

  In addition, since a temperature difference of around 200 ° C. repeatedly occurs in outer space depending on the sunlight irradiation condition, the optical system mechanism of the remote telescope is affected by this temperature. In the inventions according to claims 16 and 17, not only the incident angle adjustment of the incident light but also the adjustment of the apparatus temperature, and further the automatic correction of the observation image distortion due to the temperature difference by the computer mounted on the remote telescope. Is supposed to be installed.

  The present invention is not limited to the above description, and any embodiment according to the scope of claims is included in the present invention.

  The composite optical system of the present invention is very suitable for small satellites (microspace telescopes) because of its simple and small size and the possibility of combining various optical sensing and optical communication mechanisms. It seems that there is a possibility of meeting the demand for ultra-miniaturization in the space industry.

DESCRIPTION OF SYMBOLS 10 Optical system 20 Beam splitter 25 Reflection polarization area of beam splitter 30 Reflection mirror 35 Slit 40 Optical sensor

Claims (17)

A compound optical system that distributes a multi-wavelength image incident through a lens system or a reflective optical system to a plurality of optical sensors,
The multi-wavelength image incident from the optical system is divided into P-polarized light and S-polarized light at a predetermined intensity ratio by a beam splitter, or divided into different wavelength regions,
Of the divided image planes, one image is reflected by a reflecting mirror orthogonal to the main optical axis arranged at the focal position, is incident on the beam splitter again, and is divided again according to the characteristics of the beam splitter. , Propagating to the next optical system 2. The composite optical system according to claim 1, wherein the reflecting mirror is a half mirror having a predetermined transmission reflectance in the intensity or wavelength region with respect to the incident multi-wavelength image. A slit is formed in a predetermined part of the reflection mirror, and image information transmitted through the slit among the divided image surfaces is introduced into an optical sensor installed on the back side of the total reflection mirror. The composite optical system according to claim 1 or 2. 4. A slit image is individually arranged for each divided image divided by the beam splitter, and a slit image is individually obtained from each divided image. Composite optical system A laser oscillator and a light receiving sensor are further provided for extending the optical axis of the lens system and the reflection optical system, and the laser is transmitted and received through the same optical system as that for multi-wavelength image distribution. 4. Compound optical system according to The optical sensor arranged in the optical axis extension for each divided image divided by the beam splitter is either a visible light two-dimensional image sensor or an invisible light two-dimensional image sensor,
6. The optical sensor arranged in the extension of the optical axis of the slit light is either a linear image sensor or a spectroscopic sensor having an imaging optical system. Compound optical system 7. The composite optical system according to claim 1, wherein the reflection wavelength characteristic of the reflection mirror is adjusted by using a different metal material as a material of the reflection mirror installed in the beam splitter. 8. The composite optical system according to claim 1, wherein chromatic aberration generated in the beam splitter is corrected with respect to an image incident on the beam splitter using an optical system that corrects chromatic aberration and the like. system 9. The compound optical system according to claim 1, wherein a lens system or a reflection optical system is finely adjusted mechanically or optically to finely adjust an incident angle or an emission angle of light. 10. The composite optical system according to claim 1, further comprising a temperature sensor and a heat source for temperature control in order to stabilize the optical characteristics. A telescope that carries the combined optical system according to any one of claims 5 to 10 and performs flight observation in the sky or in outer space, and at least two types of optical observation information on an image that has passed through a beam splitter. Remote telescope equipped with a composite optical system characterized in that it is converted into digital information and stored in a storage device, and the stored observation information is transferred to a ground base by communication means 12. The composite optical system according to claim 11, wherein the information processing operations of digitalization, storage in a storage device, and transmission of stored information are performed remotely from a ground base by laser communication or radio wave communication. Remote telescope equipped with It is a remote telescope that communicates using visible light or invisible infrared light as light used for laser communication, characterized in that the light intensity on the ground is weak enough not to damage human organs A remote telescope equipped with the composite optical system according to claim 11 or 12 14. The compound optical according to claim 11, wherein a filter or a shutter for blocking or attenuating light other than a specific wavelength of a light source used for communication means from the ground is arranged in front of the light receiving sensor. Remote telescope with system The sensor for detecting the position of a light source having a specific wavelength installed on the ground is mounted, and laser communication light can be emitted in the vicinity of the light source based on communication from the ground. Telescope equipped with the compound optical system described in 16. A remote telescope equipped with a composite optical system according to claim 11, wherein an incident light capturing angle, an apparatus temperature, and the like are automatically controlled by a mounted computer. The composite optical system according to any one of claims 11 to 16, further comprising a spatial light modulation element that automatically corrects distortion of an observation image caused by a temperature difference in the atmosphere or space environment. Onboard remote telescope

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