JPH011922A - radiation scanning system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates to a four-ray scanning system and more particularly to two scanning speeds: a high scanning speed in a first direction and a low scanning speed in a second direction. , concerning a radiation scanning system that requires. The line scanning system of the present invention has a 2B scene! t
1 and belongs to the class of radiation scanning systems in which one structure operates at a high scanning speed to provide a scan line and the other structure operates at a low scanning speed to provide a frame.

U.S. Pat. No. 4,210,810 discloses a detector, a transfer lens forming a real image of the detector, a rotary scanning device positioned in the darkness with the transfer lens, and the device a concave substantially spherical mirror arranged concentrically with respect to the trajectory of the detector, the detector image being configured to move in a circular trajectory as the detector is rotated; the trajectory being in the focal plane of the mirror, so that light beams directed in different directions for different rotational positions of the rotary scanning device are produced from the mirror so that they all intersect in the pupil; and a second scanning position located at the pupil. -122 scanning devices provide orthogonal lines in the frame scan.

British patent application GB 219.958 also discloses a 1-transfer lens system for a radiation detection system.

The efficiency of scanning is determined by the scanning rotation angle of the polygonal scanning device while the focused concentrated energy is maintained on only one of the facets of the polygonal columns. Scanning efficiency can be improved by positioning the detector image closer to the scanning plane of the scanning device. When done in this manner, the light leaving the polygon leaves at an angle that is large enough to accommodate the required large angle of rotation of the polygon. A larger angle at which energy leaves the polygonal reflective facets results in the need for a larger reference mirror, such as a spherical mirror, and increases the difficulty of obtaining a good image.

SUMMARY OF THE INVENTION A radiation scanning system is disclosed having a radiation detector with a predefined aperture stop. 1st
A relay lens is positioned to form a first image of the radiation detector at a predetermined distance from the aperture stop, and a second relay lens is positioned at a predetermined distance from the first relay lens and a line The radiation detector is arranged to form a second image of the radiation detector on a scanning device. The line scanning device has a plurality of flat reflective surfaces evenly oriented around its circumference. Each reflective surface has a normal substantially perpendicular to the axis of rotation of the rotor. The rotor is disposed between the second relay lens and the second image of the radiation detector and has its axis of rotation intersecting the optical axis of the second relay lens, and as the rotor is rotated, the The second image is positioned in such a way that it is caused to travel in a substantially circular trajectory. a toroid-shaped concave mirror positioned to receive rays from a field lens positioned proximate a trajectory such that the rays reflected from any particular rotational position of said rotor are deflected onto said toroid-shaped concave mirror; be done. The toroid-shaped concave mirror normalizes the reflected light beam into a parallel light beam. A frame scanning device is positioned to reflect the collimated beam in a predetermined direction. The frame scanning device is located at the pupil formed by the intersection of different parallel light beams from the toroidal concave mirror with respect to different rotational positions of the line scanning device.

A first fold mirror is positioned between the first relay lens and a first image of the radiation detector, and a second fold mirror is positioned between the first image and the second relay lens. Ru.

The first and second fold mirrors may rotate about the optical axis between the first relay lens and the second relay lens.

It is an object of the present invention to provide a radiation scanning system that controls the position and function of the optical pupil throughout the system.

It is an object of the present invention to provide a radiation scanning system with an efficiency of 65% or more.

Another object of the present invention is to provide an rliOA line scanning system in which the size of the line scanning device is reduced through control of the optical pupil.

A further object of the present invention is to provide an improved radiation scanning system having a completely cryo-shielded radiation detector.

Yet another object of the present invention is to provide a radiation scanning system in which the cold shield used in the radiation detector acts as an aperture stop.

A further object of the invention is to provide an optical system in which the optical pupil is located on the surface of the line scanning device. ) to provide a one-line scanning system.

These and other advantages of the present invention will become more apparent from a consideration of the detailed description with reference to the accompanying drawings.

D. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a simplified block diagram of a radiation scanning system according to the present invention in which a scene 11 generates radiation such as that in the thermal infrared range. Said radiation is received and magnified by a telescope 9. A radiation scanning device 7 converts the expanded radiation into line and one frame radiation scans. A detector 3 receives the line and frame radiation scans (scanning information), converts the radiation into electrical signals representing the scanning information, and transmits the converted scanning information to the display 1 via conductors 5. The display 1 is a device such as a raster scanning cathode ray tube that responds to electrical signals. The display 1 then reproduces the scene 11 on the display in a line/frame scanning format.

FIG. 2 is a schematic diagram illustrating the radiation scanning device 7 and the detector 3. Detector 3 in the embodiment shown in this figure
is a device such as an infrared radiation detector that is cooled to increase its sensitivity to thermal infrared radiation. A cold shield 15 shields the detector 3 against undesired radiation from sources distal to the optical bundle 20 and has an aperture 17 through which the desired radiation from the scene 11 passes. The opening 17 serves as an F-diaphragm for the radiation scanning device 7. The detector 3 is interlocked by a window 4.

The description of the invention is simplified when the detector 3, insofar as the discussion of FIGS. 2 and 3 is concerned, is considered as the source of the radiation projected onto the scene 11 by the radiation scanning device 7. be done. When using this arrangement direction, the first relay lens 19 is arranged to relay the image of the detector 3 to the image point 21, and the image of the detector 3 is formed at the position of the image point 21. A fold mirror 23 is inserted into the optical bundle 20 in order to minimize the distance between the eleven apertures 17 and the image point 21.

The second relay lens 25 relays the image formed at the image point 21 onto the rotary scanning device 27 . The rotary scanning device 27 is a polygon scanner in the second and third embodiments. The first relay lens 19 and the second relay lens 25 are aspherical lenses, and the pupil 28, that is, the 101
7 is selected to be formed on one of the polygonal faces 33 of the rotary scanning device 27 in a position aligned with said optical bundle 20. A plurality of W42 images are formed along a trajectory 39 by the action of a plurality of surfaces 33 of the rotating polygon, and they are located approximately as if at a point 2 inside the rotating scanning device 27.
It appears to occur at 9.

Said rotary scanning device 27 is, as already mentioned, a polygonal scanner with seven faces in the illustrated embodiment and driven by a motor 31.

The main rotational scan [1127 is a high speed scanner and is used to produce a line scan of the detector 3. The faces 33 of the polygonal scanner are reflective and reflect the energy emitted from the detector 3 via a field lens 37 onto a toroidal concave mirror 35 .

As the polygon-shaped rotary scanning device 27 rotates,
The i position is the locus 3 where the 2611th detector 3 is formed.
Establish 9. The field lens 37 is placed close to the image formed on the trajectory 39 and deflects the image on the trajectory 39 to the toroid-shaped concave mirror 35 . The concave mirror 35 standardizes the deflected light beam and guides it to the frame scanning device 41 . The frame scanning device 41 has a mirror 43 pivoting about a point 45. The frame scanning device 41 is driven by a motor 47 (see FIG. 5) to cause frame scanning of the detector 3. The position of the frame scanning device 41 is defined by a field lens and is located at the pupil or frontage image formed by the optical system consisting of said field lens 37 and a toroidal concave mirror 35.

FIG. 3, which will be referred to next, is a side view of the 11i ray scanning device 7, in which the line scanning image of the detector 3 is transferred from the reflecting surface 33 of the polygonal body of the rotating scanning device 27 to the toroid-shaped concave mirror. 35 shows the action of the field lens 37 deflecting toward 35. The advantage of using or selecting a suitable field lens 37 is that the position of the pupil by causing the rays leaving the image trajectory 39 to originate from a more distant pupil position, and therefore the a with respect to the position of the framing mirror 44, is ,
1I control, increasing the focal length of the reference mirror (concave mirror 35) and/or selection of the field of view of the radiation scanning system 10, and the use of smaller sized reference mirrors to minimize imaging problems. These advantages, combined with the use of a toroid-shaped concave mirror, which has superior imaging performance that surpasses that of a spherical mirror of the same size, make the polygonal scanning device superior in scanning over large rotational angles. Enables to generate scanning efficiency.

The use of a multiple imaging relay lens system, including the first relay lens 19 and the second relay lens 25, allows for the minimization of the size of the pupil 28 on the surface of a polygon, which is not possible with a single relay lens. Helpful. This minimized pupil allows the rotary scanning device 27 to scan over a large scan angle without the pupil energy being on two planes 33.

This results in improved utilization and higher efficiency compared to systems based on the prior art, as already described.

Referring to FIG. 4, the pupil 28 is an image of the aperture stop 17.
shows that the shape reduces the size of the pupil 28 on the plane of the polygon 46 and has two flat parts 5 aligned parallel to each other.
It has 1.53. In the embodiment of FIG. 4, the separation distance between the flat portions 51.53 is the oppositely located circular arc 55.53.
It is 0.8 times the diameter of 57. As a result of this, the aperture stop has only 90% of its open area as a circular aperture with a diameter comparable to that of a circular arc. The aperture stop 17 in FIG. 4 is positioned such that the flat portion 51.53 is arranged perpendicular to the direction of rotation of the rotary scanning device 27. Since the pupil on the surface 33 is an image of the aperture 17 and the aperture is truncated by 20% in the scanning direction, the energy width of the second relay lens 25 is circular with a radius of the arc 55.57. 10% smaller than that of the aperture. With such a truncated aperture diaphragm, the rotary scanning device 27 can scan over a larger angle, ie, better utilization can be achieved with only a 10% reduction in the aperture area.

Referring now to FIGS. 5 and 6, a first fold mirror 23 and a second fold mirror 24 reduce the physical spacing between the detector 3 and the rotary scanning device 27 and It is located to facilitate the placement of the detector and associated cooling equipment. In the embodiment of FIG. 5, which shows the packaging of the ll1DJ line scanning device, the fold mirror 24 is arranged and rotatably positioned about the optical axis 89. - Once in position, the catch 81 holds the seven flange 83 in place to prevent rotation of the fold mirror 24. Such an array has a maximum of 180
Allow rotation up to '. Similarly, the fold mirror 23 can be rotated 360'' about the optical axis 91 and is secured fixedly by the flange 85 and the fastener 87. FIG. 6 is a side view of FIG. The flexibility of device packaging is further illustrated.

Regarding the above description, the following sections are further disclosed.

(1) A radiation scanning system, the system comprising: a radiation detector having a predefined aperture stop; a first relay lens arranged to form a first image of the radiation detector; a second relay lens positioned at a predetermined distance from the relay lens and positioned to form a second image of the radiation detector and relay the pupil onto the line scanning device; a rotor having a number of flat reflective surfaces evenly spaced along its circumference and positioned to receive the relayed pupils, each of said reflective surfaces the rotor having a normal substantially perpendicular i to the axis of rotation, the rotor being disposed between the second relay lens and the second image of the radiation detector, and the rotor having its axis of rotation intersecting the optical axis of the second relay lens, the octavo axis being arranged in a manner such that the second image moves in a substantially circular trajectory as the rotor rotates; , a substantially toroid-shaped concave mirror for deflecting a ray reflected from any particular rotational position of said rotor onto said substantially toroid-shaped concave mirror positioned to receive the reflected ray; and a field lens operatively positioned in a circular trajectory, such that two front substantially toroidal concave mirrors normalize said reflected rays into a parallel beam and define the position of a second pupil. Cooperative with the field lens, the system further comprises a frame scanning device positioned to reflect a parallel beam of light in a predetermined direction, and the frame scanning device is located at the second pupil. A radiation scanning system featuring:

(2) In the radiation scanning system described in the first tomb,
Furthermore, the first relay lens and the first relay lens of the radiation detector
A radiation scanning system having a first fold mirror positioned in a first optical path between the image and the image.

(3) In the radiation scanning system described in the second tomb,
The radiation scanning system further includes a second fold mirror positioned in a second optical path between the first image of the radiation detector and the second relay lens.

(4) In the radiation scanning system described in paragraph 3,
A radiation scanning system, wherein the first fold mirror is rotatably mounted along the first optical path and the second fold mirror is rotatably mounted along the second optical path.

(5) In the radiation scanning system described in paragraph 1,
A radiation scanning system, wherein the field lens is located proximate a third pupil caused by reflected light from the line scanning device.

(6) In the radiation scanning system described in paragraph 5,
The radiation scanning system further includes a first fold mirror positioned in a first optical path between the first relay lens and a first image of the group 114 radiation detector.

(7) In the radiation scanning system described in paragraph 6,
Furthermore, the release tJ4Ii! The first image of the detector and the second image
A radiation scanning system having a second fold mirror positioned in an optical path between the relay lens and the relay lens.

(8) In the radiation scanning system described in paragraph 7,
A radiation scanning system, wherein the first fold mirror is rotatably mounted along the first optical path and the second fold mirror is rotatably mounted along the second optical path.

(9) In the radiation scanning system described in paragraph 1,
The aperture stop has a round end of a first radius and a round end of the first radius.
A radiation scanning system having a rectangular hole with parallel side walls separated from each other by a distance less than twice.

(10) In the radiation scanning system described in item 9, °C1
The radiation scanning system further includes a first fold mirror positioned in a first optical path between the first relay lens and the first image of the triOA line detection vapor.

(11) The radiation scanning system according to item 10, further comprising a second fold mirror located in an optical path between the first flEl of the radiation detector and the second relay lens.

(12) In the radiation scanning system according to item 11,
A radiation scanning system, wherein the first fold mirror is rotatably mounted along the first optical path and the second fold mirror is rotatably mounted along the second optical path.

(13) A radiation scanning system, the system comprising a radiation detector device for converting the radiation into an electrical signal and a predefined aperture stop for focusing the radiation to be converted. a detector arrangement, a first relay lens arrangement for forming a first and second image of the radiation detector arrangement, the first relay lens arrangement being located at a predetermined distance from the first relay lens arrangement and a second image of the radiation detector arrangement; and a second relay lens arrangement disposed to form a pupil and relay the pupil onto the line scanning device, the line scanning device having a plurality of flat reflective surfaces for reflecting and relaying the beam of radiation. the second relay lens device for receiving a pupil, each reflective surface having a normal substantially perpendicular to the axis of rotation of the rotor; and a second part of the radiation detector device, and the rotor intersects the axis of rotation with the optical axis of the second relay lens device, and the line scanning device scans the second image. arranged to convert the reflected beam into a line scan, the system further comprising: a substantially toroid-shaped concave mirror arrangement for collimating the reflected beam into a parallel beam; and any particular rotating portion of the rotor. said substantially toroidal concave mirror device positioned to receive reflected light rays reflected from said substantially toroidal concave mirror device to deflect onto said substantially toroidal concave mirror device and to define the location of a second pupil; and a frame scanning device positioned to reflect the collimated beam in a predetermined direction, the frame scanning device being disposed in the second pupil. A radiation scanning system characterized by:

14. The radiation scanning system of claim 13, wherein the field lens device is operatively located in close proximity to a third pupil caused by reflected light from the line scanning device.

(15) The radiation scanning system J3 according to paragraph 13, wherein the frontage aperture has a wide end with a first radius and parallel side walls separated from each other by a distance less than twice the first radius. jjs[fl) I-line scanning system with rectangular holes.

(16) In the radiation 11) J-ray scanning system described in paragraph 15, further, a first relay lens device between the first relay lens device and the first image of the radiation detector device for bending the radiation in a first direction. A radiation scanning system having a first fold mirror positioned in an optical path of the system.

(17) In the radiation scanning system according to item 16,
The radiation scanning system further comprises a second fold mirror positioned in the first direction in the darkness between the first @ of the radiation detector Via and the second relay lens device for folding the radiation in a second direction.

(18) The tIi copper wire scanning system according to item 17, further comprising a via for exchanging the first direction and the second direction.

(19) A radiation scanning method, the method comprising: converting radiation into an electrical signal by means of a radiation gAlit detector having a predefined aperture aperture; and forming a first image of the radiation detector by a first relay lens device; forming a second image of the radiation detector device on a line scanning device by a second relay lens device located at a predetermined distance from the first relay lens device and relaying the pupil onto the line scanning device; and converting the second image into a line scan of reflected light rays by the line scanning device, the line scanning device having a pupil for reflection of the second image rays and for receiving the pupil. having a rotor with a plurality of flat reflective surfaces evenly spaced along the circumference;
each of the reflective surfaces has a normal substantially perpendicular to the axis of rotation of the rotor, and the rotor
the rotor is positioned between the relay lens device and the second image of the radiation detector device, and the rotor has its axis of rotation aligned with the second image of the radiation detector device;
intersecting the optical axis of a relay lens arrangement and located between the second relay lens arrangement and the second image, and the method further includes normalizing the reflected light beam into a parallel beam by a substantially toroid-shaped concave mirror. on a substantially toroidal concave mirror positioned to receive the reflected light beam by a field lens cooperating with the substantially toroidal concave mirror to define the position of a second pupil; , deflecting a reflected beam of light reflected from any particular rotational position of the rotor; and reflecting a parallel beam of light by a frame scanning device located in a second pupil in a predetermined direction. A radiation scanning method characterized by

(20) The method according to paragraph 19, further comprising a rectangular hole having a wide end of a first radius and parallel side walls separated from each other by a distance less than twice the first radius. A radiation scanning method comprising the step of restricting radiation of the radiation detector by an aperture diaphragm.

Tribe 9 AI! i! The scanning system is used with a radiation detector having a predefined l110 aperture. A first relay lens is positioned at a predetermined distance from the aperture stop. i! a second relay lens is positioned to form a first image of the radiation detector and a second relay lens is positioned at a predetermined distance from the first relay lens and forms a second image of the radiation detector.
The device is arranged to form an image on a line scanning device. The line scanning device has a rotor with a plurality of flat reflective surfaces evenly spaced along its circumference. J5 of each of these reflective surfaces is 4° to the right of a normal substantially perpendicular to the axis of rotation of the rotor. The rotor is located between the second relay lens and the second image of the radiation detector and has its axis of rotation intersecting the optical axis of the second relay lens, and as the rotor is rotated, the second The images are positioned in such a way that they are caused to move in a substantially circular trajectory. A substantially toroid-shaped concave mirror deflects a deflected ray from a field lens positioned at a trajectory such that the ray reflected from any particular rotational position of said rotor is deflected onto said substantially toroid-shaped concave mirror. positioned to receive. The substantially toroidal concave mirror normalizes the reflected beam into a parallel beam. A frame scanning device is positioned to reflect the collimated beam in a predetermined direction. The frame scanning device is located at the pupil formed by the intersection of different parallel light beams from the substantially toroidal concave mirror with respect to different rotational positions of the line scanning device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a radiation scanning system according to the present invention. FIG. 2 is a schematic diagram showing an optical lens arrangement of the radiation scanning system of FIG. FIG. 3 is a side view of the optical lens device of FIG. 2. FIG. 4 is a diagram illustrating the image of the pupil and the aperture diaphragm in the line scanning device of FIG. 1. 5 and 6 are schematic diagrams illustrating the packaging of the radiation Dj4a scanning system of FIG. 1. On the drawing, 3...detector, 7...radiation scanning method, 1
7... Aperture, 19... First relay lens, 23.24
...Fold mirror, 25...Second relay lens,
27... Rotating scanning device, 28... Pupil, 33...
Surface, 35...Troid mirror, 37...Field lens, 39...Trajectory.

Claims (1)

[Claims] A radiation scanning system, the system comprising: a radiation detector having a predefined aperture stop; a first relay lens arranged to form a first image of the radiation detector; and from the first relay lens. a second relay lens positioned at a predetermined distance and positioned to form a second image of the radiation detector and relay the pupil onto the line scanning device, the line scanning device having a plurality of a rotor having flat reflective surfaces evenly spaced along its circumference and positioned to receive the relayed pupils, each of the reflective surfaces substantially relative to the axis of rotation of the rotor; has a normal perpendicular to , the rotor is disposed between the second relay lens and a second image of the radiation detector, and the rotor has its axis of rotation with the optical axis of the second relay lens. intersecting and the rotational axes are arranged in a manner such that the second image moves in a substantially circular trajectory as the rotor rotates, and the system further comprises a substantially toroidal shaped concave mirror,
operatively positioned in a substantially circular trajectory for deflecting light rays reflected from any particular rotational position of the rotor onto the substantially toroid-shaped concave mirror positioned to receive the reflected rays; a field lens, the substantially toroidal concave mirror cooperating with the field lens to normalize the reflected rays into a parallel beam and define a second pupil position; A radiation scanning system comprising a frame scanning device positioned to reflect a collimated beam of light in a predetermined direction, the frame scanning device being located in a second pupil.