CA2111200C - Electronic high-speed camera - Google Patents
Electronic high-speed cameraInfo
- Publication number
- CA2111200C CA2111200C CA002111200A CA2111200A CA2111200C CA 2111200 C CA2111200 C CA 2111200C CA 002111200 A CA002111200 A CA 002111200A CA 2111200 A CA2111200 A CA 2111200A CA 2111200 C CA2111200 C CA 2111200C
- Authority
- CA
- Canada
- Prior art keywords
- speed camera
- video sensors
- electronic high
- camera according
- mirror
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 230000003287 optical effect Effects 0.000 claims abstract description 26
- 230000005693 optoelectronics Effects 0.000 claims abstract description 10
- 239000004065 semiconductor Substances 0.000 claims abstract description 7
- 238000012634 optical imaging Methods 0.000 claims abstract description 5
- 230000015654 memory Effects 0.000 claims description 21
- 230000001360 synchronised effect Effects 0.000 claims description 11
- 238000003384 imaging method Methods 0.000 claims description 5
- 230000004048 modification Effects 0.000 abstract description 5
- 238000012986 modification Methods 0.000 abstract description 5
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 8
- 238000009432 framing Methods 0.000 description 4
- 230000001960 triggered effect Effects 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 230000001419 dependent effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- VVNCNSJFMMFHPL-VKHMYHEASA-N D-penicillamine Chemical compound CC(C)(S)[C@@H](N)C(O)=O VVNCNSJFMMFHPL-VKHMYHEASA-N 0.000 description 1
- 241000713385 Idiodes Species 0.000 description 1
- 101150068246 V-MOS gene Proteins 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 229940075911 depen Drugs 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000001208 nuclear magnetic resonance pulse sequence Methods 0.000 description 1
- 238000001454 recorded image Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
- H04N3/02—Scanning details of television systems; Combination thereof with generation of supply voltages by optical-mechanical means only
- H04N3/08—Scanning details of television systems; Combination thereof with generation of supply voltages by optical-mechanical means only having a moving reflector
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B29/00—Combinations of cameras, projectors or photographic printing apparatus with non-photographic non-optical apparatus, e.g. clocks or weapons; Cameras having the shape of other objects
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B39/00—High-speed photography
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/50—Constructional details
- H04N23/55—Optical parts specially adapted for electronic image sensors; Mounting thereof
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/40—Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
- H04N25/41—Extracting pixel data from a plurality of image sensors simultaneously picking up an image, e.g. for increasing the field of view by combining the outputs of a plurality of sensors
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
- Studio Devices (AREA)
- Cameras In General (AREA)
- Stroboscope Apparatuses (AREA)
Abstract
Electronic high speed camera with an optoelectronic recording system which is used without modification both in the front-light mode and in the backlight mode. The recording system is provided with a plurality of separate semiconductor video sensors (2) and with an optical imaging system comprising a camera objective (3) common to the video sensors (2) and a mirror pyramid (1), the video sensors (2) being arranged in a circle around the mirror pyramid, wherein to each of the video sensors an electronic shutter means is assigned. For the backlight mode, an optical backlight system (5a, 5b) and a plurality of lumped flashlight sources (4a, 4b) arranged in a circle are disposed before the camera objective (3) which sources can be imaged by the optical backlight system (5a, 5b) and the camera objective (3) to in each case one of the mirror surfaces of the mirror pyramid (1). (Fig. 3)
Description
, Electronic high-speed camera The invention relates to an electronic high-speed camera for the recording of fastly moved objects, including visualized events, comprising a plurality of separate semiconductor video sensors arranged in the imaging beam path of an optical imaging system and connected to associated image memories.
In a known device for electronic image recording (DE-PS 24 60 625) fastly occuring events as, e.g., the progress of an elctric arc, are recorded in a front-light mode by means of optoelectronic semiconductor image converters like photocells, phototransistors or even photodiodes which are arranged in a line or in a matrix with several lines behind a lense system and which are interrogated cyclically one after the other.
Further, high-speed film cameras with rotary drums, mirrors or prisms are used for the photographic recording of fastly moved objects, including visualized events (e.g. flows). These have a drawback in that the photograms cannot be judged and evaluated but after the exposure of the film. Therefore, a direct interference in the event in the light of the photograms is not possible. The entirely electronic Cranz-Schardin camera according to the Review of Scientific Instruments, Vol 62 No.
In a known device for electronic image recording (DE-PS 24 60 625) fastly occuring events as, e.g., the progress of an elctric arc, are recorded in a front-light mode by means of optoelectronic semiconductor image converters like photocells, phototransistors or even photodiodes which are arranged in a line or in a matrix with several lines behind a lense system and which are interrogated cyclically one after the other.
Further, high-speed film cameras with rotary drums, mirrors or prisms are used for the photographic recording of fastly moved objects, including visualized events (e.g. flows). These have a drawback in that the photograms cannot be judged and evaluated but after the exposure of the film. Therefore, a direct interference in the event in the light of the photograms is not possible. The entirely electronic Cranz-Schardin camera according to the Review of Scientific Instruments, Vol 62 No.
2, pp. 364 to 368, Bretthauer et al. "An Electronic Cranz-Schardin Camera", certainly furnishes an immediately available sequence of videograms; it is, however, not provided for a front-light imaging operation. This backlight mode high-speed camera can be equipped with a plurality of semiconductor video sensors connected to associated image memories, which sensors are arranged in a circle around a mirror pyramid, each of the mirror surfaces thereof being assigned to one of the video sensors and to one of a plurality of light emitting diodes arranged in a circle beyond the object to be recorded and being cyclically pulse-operated one after the other.
However, for a photographic recording of fastly moved objects and visualized events, especially single or not periodical h ~ ,. i. i~, ~ '3 events, a high-speed camera is required which can operate both in the backlight mode and in the front-light mode dependent on the kind of the object. - -The invention is based on the problem to devise an electronic high-speed camera which operates without wear and which can be used both in the backlight mode and in the front-light mode without modification of its optoelectronic recording system.
Preferably, the videograms shall be available i -~;ately (screen, printer) and shall be suitable as computer file for a direct electronic evaluation.
The electronic high-speed camera according to the invention in solving said problem comprises an optoelectronic recording system with a plurality of separate semiconductor video sensors connected to associated image memories and an optical imaging system imaging the im~ge of the object on the video sensors and comprising a camera objective common to the video sensors and a mirror pyramid which faces the objective with its pyramid tip and lies with its axis in the optical axis of the camera objective. The video sensors are arranged in a circle around -the optical axis of the objective and the mirror py~
comprises a plurality of mirror surfaces assigned in each case to one of the video sensors. To each of the ~ideo sensors a triggerable electronic shutter means is assigned.
This optoelectronic recording system is suitable without modification for both the front-light mode and the backlight mode. For the backlight operation an optical backlight system is arranged in series, the ob~ect being located in the beam path thereof. Herein, a plurality of lumped flashlight sources are arranged in a circle before the optical backlight system which can be imaged through the optical backlight system and through the camera objective each on one of the mirror surfaces, the shutter means being synchronized with the flashlight sources.
In this way, the electronic high-speed camera of the invention : . .
can be o~erated in two different modes, due to its novel optical and electronic arrangement. In the backlight mode, the camera operates according to a modified Cranz-Schardin principle. The modification lies in that the semiconductor S video sensors each have not an objective of its own but the camera has only one camera objective cl -n to all video sensors each being able to furnish a two-~;~~nciional image whereby the construction as well as the ad~ustment are substantially simplified. In the ~ront-light mode in which the optical backlight system and the flashlight sources are uncoupled, the beam of rays is simultaneously projected to all video sensors due to the beam splitting effect of the objective-mirror ~yl, id arrangement. These video sensors are activated cyclically one after the other by their shutter electronics in such a way that thereby an image sequence results which can be stored in the image memories, which can be combined in an image memory unit with respective several image memory inputs, and can be processed in a preferably connected image processor.
The flashlight sources can, e.g., be spark light sources, they are, however preferably pulse operated light emitting idiodes or laser diodes which especially emit visible light. The flashlight sources can be synchronized with the image memories.
The video sensors, each designed as a detector matrix, are preferably synchronized with eachother and with the image memories. The shutter means are preferably asynchronously triggerable and synchronized with the image memories. For very short shutter intervals, the shutter means can be designed as image intensifier placed in front of the video sensors.
Preferably, a freely proyl~ ~hle sequenzer, controlling the shutter means, the image memories and in a given case the flashlight sourceB i6 connected thereto for optimal conditions and interference possibilities. Preferahly, eight video sensors are provided; however, also fewer or more video sensors can be used.
The advantages reached by the invention consist especially in - - : ~ ~ .. ~ -that, with a relatively simple construction, one can produce high-speed backlight videograms and high-speed front-light videograms. Further, the camera allows an on-line observation in both modes. The recorded images can, with a respective layout of the camera, electronically be stored, transferred, evaluated, processed and ; -~;ately be printed. The camera is not subjected to ~ch~n; cal wear (has no movable parts) and has no consumption of materials (no film, developer and so on).
10 The invention is illustrated by means of embodiments being -obvious from the drawings at least schematic.
The figures 1 and 2 show two embodiments of the optoelectronic recording system of an electronic high-speed camera according lS to the invention. Figs. 3 and 4 show the structure of the camera in the bac~light mode (fig. 3) and in the front-light mode (fig. 4). Fig. 5 indicates the electronic circuit diagram of the high-speed camera according to the invention.
20 The optoelectronic recoxding system of the high-speed camera of --fig. 1 has a nearly potshaped casing with a camera ob~ctive 3, ;
; behind which in the casing a mirror pyramid 1 is disposed coaxially with respect to the objective 3, the pyramid tip thereof facing the objective 3 and the mirror surfaces thereof deflecting the optical rays to the video sensors 2 arranged on a circle around this mirror pyramid with the center of the -circle on the axis of the mirror pyramid 1, the video sensors being perpendicularly aligned to the axis thereof. The number of the mirror surfaces of the mirror pyramid 1 coincides with the number of the video sensors. Half of the aperture angle of the thought cone comprising the side edges of the mirror pyramid 1 amounts preferably to 45~. The deflection of the beam path causes a tilting and a reflection of the images. In order to compensate for the tilting, the sensors are turned around ;
their own optical a~es each by an angle of 360~ per number of the sensors. The reflection of the images can be retransformed by hardware (e.g. by reversely reading out of the image lines) or by software by means of the image processor. However, the --~ f . ~ .L ~
tilting and the reflection can also be avoided in an optical way by a double deflection of the beam path. Fig. 2 shows a variant of the optoelectronic recording system 1, 2 and 3 in which the rays deflected by the side surfaces of the mirror pyL~ i d 1 are deflected again by the additional mirrors 12 which are arranged inclined by 45~ with respect to the optical axis according to fig. 2. The number of these mirrors 12 coincides with the number of sensors as well. In this variant, the video sensors are preferably arranged in such a way, that their active surfaces are lying in a plane perpendicular to the optical axis of the camera, which is the case in fig. 2, according to which the sensors 2 are arranged at the bottom of the casing in a circle and are aligned with the mirrors 12 in parallel with the optical axis.
The video sensors 1 each comprise electronic shutter means 7 (fig. 5), the shutter interval of which preferably is very short. These shutter means operate asynchronous, i.e. an image is ; ~iately recorded after appearance of an external trigger signal and is distributed. The image is then stored in an image memory 8, to which an image processor is connected. The number of the image memory inputs (channels) corresponds to the number of sensors 2. The shutter means 7 of the sensors 2 and of the image memories 8 are triggered by a sequencer 11. This sequencer 11 generates a series of pulses after an electrical or manuell start signal and a trigger signal of the object. The number, the ch~nnel number and the spacing between the pulses can be freely programmable.
, This pulse sequence must often be synchronized with the object (event) to be videographed. In case of an object the function of which can be triggered or synchronized by an electrical signal, it is triggered or synchronized by a trigger signal generated by the sequencer 11. In the other cases a trigger signal is derived from the object and is delivered to the sequencer 11.
The camera operates in two modes: in the backlight mode (fig.
.9 '-- r~ ' ,.. _. t_ ~ IJ
However, for a photographic recording of fastly moved objects and visualized events, especially single or not periodical h ~ ,. i. i~, ~ '3 events, a high-speed camera is required which can operate both in the backlight mode and in the front-light mode dependent on the kind of the object. - -The invention is based on the problem to devise an electronic high-speed camera which operates without wear and which can be used both in the backlight mode and in the front-light mode without modification of its optoelectronic recording system.
Preferably, the videograms shall be available i -~;ately (screen, printer) and shall be suitable as computer file for a direct electronic evaluation.
The electronic high-speed camera according to the invention in solving said problem comprises an optoelectronic recording system with a plurality of separate semiconductor video sensors connected to associated image memories and an optical imaging system imaging the im~ge of the object on the video sensors and comprising a camera objective common to the video sensors and a mirror pyramid which faces the objective with its pyramid tip and lies with its axis in the optical axis of the camera objective. The video sensors are arranged in a circle around -the optical axis of the objective and the mirror py~
comprises a plurality of mirror surfaces assigned in each case to one of the video sensors. To each of the ~ideo sensors a triggerable electronic shutter means is assigned.
This optoelectronic recording system is suitable without modification for both the front-light mode and the backlight mode. For the backlight operation an optical backlight system is arranged in series, the ob~ect being located in the beam path thereof. Herein, a plurality of lumped flashlight sources are arranged in a circle before the optical backlight system which can be imaged through the optical backlight system and through the camera objective each on one of the mirror surfaces, the shutter means being synchronized with the flashlight sources.
In this way, the electronic high-speed camera of the invention : . .
can be o~erated in two different modes, due to its novel optical and electronic arrangement. In the backlight mode, the camera operates according to a modified Cranz-Schardin principle. The modification lies in that the semiconductor S video sensors each have not an objective of its own but the camera has only one camera objective cl -n to all video sensors each being able to furnish a two-~;~~nciional image whereby the construction as well as the ad~ustment are substantially simplified. In the ~ront-light mode in which the optical backlight system and the flashlight sources are uncoupled, the beam of rays is simultaneously projected to all video sensors due to the beam splitting effect of the objective-mirror ~yl, id arrangement. These video sensors are activated cyclically one after the other by their shutter electronics in such a way that thereby an image sequence results which can be stored in the image memories, which can be combined in an image memory unit with respective several image memory inputs, and can be processed in a preferably connected image processor.
The flashlight sources can, e.g., be spark light sources, they are, however preferably pulse operated light emitting idiodes or laser diodes which especially emit visible light. The flashlight sources can be synchronized with the image memories.
The video sensors, each designed as a detector matrix, are preferably synchronized with eachother and with the image memories. The shutter means are preferably asynchronously triggerable and synchronized with the image memories. For very short shutter intervals, the shutter means can be designed as image intensifier placed in front of the video sensors.
Preferably, a freely proyl~ ~hle sequenzer, controlling the shutter means, the image memories and in a given case the flashlight sourceB i6 connected thereto for optimal conditions and interference possibilities. Preferahly, eight video sensors are provided; however, also fewer or more video sensors can be used.
The advantages reached by the invention consist especially in - - : ~ ~ .. ~ -that, with a relatively simple construction, one can produce high-speed backlight videograms and high-speed front-light videograms. Further, the camera allows an on-line observation in both modes. The recorded images can, with a respective layout of the camera, electronically be stored, transferred, evaluated, processed and ; -~;ately be printed. The camera is not subjected to ~ch~n; cal wear (has no movable parts) and has no consumption of materials (no film, developer and so on).
10 The invention is illustrated by means of embodiments being -obvious from the drawings at least schematic.
The figures 1 and 2 show two embodiments of the optoelectronic recording system of an electronic high-speed camera according lS to the invention. Figs. 3 and 4 show the structure of the camera in the bac~light mode (fig. 3) and in the front-light mode (fig. 4). Fig. 5 indicates the electronic circuit diagram of the high-speed camera according to the invention.
20 The optoelectronic recoxding system of the high-speed camera of --fig. 1 has a nearly potshaped casing with a camera ob~ctive 3, ;
; behind which in the casing a mirror pyramid 1 is disposed coaxially with respect to the objective 3, the pyramid tip thereof facing the objective 3 and the mirror surfaces thereof deflecting the optical rays to the video sensors 2 arranged on a circle around this mirror pyramid with the center of the -circle on the axis of the mirror pyramid 1, the video sensors being perpendicularly aligned to the axis thereof. The number of the mirror surfaces of the mirror pyramid 1 coincides with the number of the video sensors. Half of the aperture angle of the thought cone comprising the side edges of the mirror pyramid 1 amounts preferably to 45~. The deflection of the beam path causes a tilting and a reflection of the images. In order to compensate for the tilting, the sensors are turned around ;
their own optical a~es each by an angle of 360~ per number of the sensors. The reflection of the images can be retransformed by hardware (e.g. by reversely reading out of the image lines) or by software by means of the image processor. However, the --~ f . ~ .L ~
tilting and the reflection can also be avoided in an optical way by a double deflection of the beam path. Fig. 2 shows a variant of the optoelectronic recording system 1, 2 and 3 in which the rays deflected by the side surfaces of the mirror pyL~ i d 1 are deflected again by the additional mirrors 12 which are arranged inclined by 45~ with respect to the optical axis according to fig. 2. The number of these mirrors 12 coincides with the number of sensors as well. In this variant, the video sensors are preferably arranged in such a way, that their active surfaces are lying in a plane perpendicular to the optical axis of the camera, which is the case in fig. 2, according to which the sensors 2 are arranged at the bottom of the casing in a circle and are aligned with the mirrors 12 in parallel with the optical axis.
The video sensors 1 each comprise electronic shutter means 7 (fig. 5), the shutter interval of which preferably is very short. These shutter means operate asynchronous, i.e. an image is ; ~iately recorded after appearance of an external trigger signal and is distributed. The image is then stored in an image memory 8, to which an image processor is connected. The number of the image memory inputs (channels) corresponds to the number of sensors 2. The shutter means 7 of the sensors 2 and of the image memories 8 are triggered by a sequencer 11. This sequencer 11 generates a series of pulses after an electrical or manuell start signal and a trigger signal of the object. The number, the ch~nnel number and the spacing between the pulses can be freely programmable.
, This pulse sequence must often be synchronized with the object (event) to be videographed. In case of an object the function of which can be triggered or synchronized by an electrical signal, it is triggered or synchronized by a trigger signal generated by the sequencer 11. In the other cases a trigger signal is derived from the object and is delivered to the sequencer 11.
The camera operates in two modes: in the backlight mode (fig.
.9 '-- r~ ' ,.. _. t_ ~ IJ
3) it operates according to the Cranz-Schardin principle (Zeitschrift fur Physik 56 (1929), pages 147-183). This principle, however, was modified by another optical arrangement. The modification lies in that the camera comprises an objective 3 common to all video sensors whereby both, the construction and the adjustment are substantially simplified.
In this arrangement, the light is generated by pulse-operated flashlight point sources 4. Preferred as light sources are high efficiency LEDs. These LEDs can be coupled to photoconductors and can electrically directly (without conducting cable) be connected tc the pulse amplifier 10 (fig. 5). Thereby, a favourable shape of the light output with a small diameter is obtained and the emitted light becomes substantially uniformer.
Further, the distortion of the electrical control pulses is avoided which can be caused b~ the unmatching of the diode cable. The light sources, the number of which coincides with that of the video sensors 2 (e.g. eight), are arranged on a common circle, the center of which is lying in the axis of the optical system, and are aligned in parallel with the axis of the optical system. They mostly are at the focus distance of the first lense 5a of the optical backlight system 5. The ~;
object to be videographed is situated in the parallel beam of light resulting thereby. After passage through and around the object, the light is prefocussed by the second lense 5b of the optical system 5. Thereby, the light is collected in the camera objective 3 and the light losses are reduced. The distance between the mirror pyramid 1 and the camera objective 3 is selected such that the light sources are sharpl~ imaged on the respectively corresponding mirror surface of the mirror pyramid 1. As this is the narrowest spot of the beam path, the images are optimum separated from each other by the mirror pyramid 1.
The photoactive faces of the video sensors are lying in tangential planes of a circle the radius of which is preferably selected such that the sum of the radius and of the dis~ance between the objective 3 and the tip of the mirror pyramid 1 is equal to the distance of the image plane from the objective.
Thereby, a sharp image of the object on the respective sensor is ensured.
' V f~
After ~he starting pulse and, depen~nt on the kind of the object, after initiating the event by the object trigger signal generated by the sequencer 11 or after an object trigger signal given to the sequencer from the object, a sequential lighting of the light sources, controlled by the sequencer 11, occurs.
The lighting of each light source corresponds to the imaging of the object on the video sensor assigned to this light source.
In this way, an image sequence results on the video sensors 2 which is taken over by the image -,~y 8 due to the image memory trigger signal, subsequently generated by the sequencer, and is stored. If also the shu~ter means 7 of the video sensors 2 are triggered by the sequencer in synchronism with the lighting of the light sources, the dynamics and the signal/noise ratio of the stored images are substantially increased. This is preferably used if the exposures must be performed in the presence of stray light (e.g. daylight). In this case, the outside light will affect the image oniy during the active shutter interval (e.g. 0.1 ms) and not during the whole integration interval ~40 ms at CCIR standards).
The ~ framing rate of the camera in the backlight mode depends on the -~1 flash succession frequency of the light sources. The flash succession frequency obtainable at the present time with the V-MOS-controlled light emitting diodes is about 10 NHz. When using laser light sources, substantially higher framing rates can be obtained.
In the front-light mode (fig. 4) the object 6 is sLmultaneously imaged on all video sensors 2, due to the beam-splitting effect of the mirror pyramid. The optical, mechanical and electrical arrangement of the optoelectronic recording system 1, 2, 3 of the camera according to fig. 1 and 2, respectively, ~ ~in~
unchanged. After the starting pulse and depending on the kind of the object after initiating the event by the object trigger signal generated by the sequencer or after a object trigger signal given to the sequencer from the object, a seguential activation of the shutter means 7 of the video sensors occurs, controlled by the sequencer 11. The image sequence obtAine~ in 3 ~
8 : :
this way is taken over by the image memory 8 and is stored due ~.
$o the trigger signal subsequently generated by the sequencer 11 .
The ~-~i framing rate of the camera in the front-light mode is dependent on the ~i n 1 shutter interval of the video sensors 2. The shortest shutter interval obtainable at the :
present time is abol-t 0.1 ms correspo~ing to a maximum framing ~-rate of 10 kHz (without temporary overlapping). At short shutter intervals, the ob~ect must be illuminated to a greater extent. Substantially higher f. ing rates without proportionally increased illumination can, however, be realized by a layout of each of the video sensors 2 with an image intensifier taking charge of the shut$er function.
In this arrangement, the light is generated by pulse-operated flashlight point sources 4. Preferred as light sources are high efficiency LEDs. These LEDs can be coupled to photoconductors and can electrically directly (without conducting cable) be connected tc the pulse amplifier 10 (fig. 5). Thereby, a favourable shape of the light output with a small diameter is obtained and the emitted light becomes substantially uniformer.
Further, the distortion of the electrical control pulses is avoided which can be caused b~ the unmatching of the diode cable. The light sources, the number of which coincides with that of the video sensors 2 (e.g. eight), are arranged on a common circle, the center of which is lying in the axis of the optical system, and are aligned in parallel with the axis of the optical system. They mostly are at the focus distance of the first lense 5a of the optical backlight system 5. The ~;
object to be videographed is situated in the parallel beam of light resulting thereby. After passage through and around the object, the light is prefocussed by the second lense 5b of the optical system 5. Thereby, the light is collected in the camera objective 3 and the light losses are reduced. The distance between the mirror pyramid 1 and the camera objective 3 is selected such that the light sources are sharpl~ imaged on the respectively corresponding mirror surface of the mirror pyramid 1. As this is the narrowest spot of the beam path, the images are optimum separated from each other by the mirror pyramid 1.
The photoactive faces of the video sensors are lying in tangential planes of a circle the radius of which is preferably selected such that the sum of the radius and of the dis~ance between the objective 3 and the tip of the mirror pyramid 1 is equal to the distance of the image plane from the objective.
Thereby, a sharp image of the object on the respective sensor is ensured.
' V f~
After ~he starting pulse and, depen~nt on the kind of the object, after initiating the event by the object trigger signal generated by the sequencer 11 or after an object trigger signal given to the sequencer from the object, a sequential lighting of the light sources, controlled by the sequencer 11, occurs.
The lighting of each light source corresponds to the imaging of the object on the video sensor assigned to this light source.
In this way, an image sequence results on the video sensors 2 which is taken over by the image -,~y 8 due to the image memory trigger signal, subsequently generated by the sequencer, and is stored. If also the shu~ter means 7 of the video sensors 2 are triggered by the sequencer in synchronism with the lighting of the light sources, the dynamics and the signal/noise ratio of the stored images are substantially increased. This is preferably used if the exposures must be performed in the presence of stray light (e.g. daylight). In this case, the outside light will affect the image oniy during the active shutter interval (e.g. 0.1 ms) and not during the whole integration interval ~40 ms at CCIR standards).
The ~ framing rate of the camera in the backlight mode depends on the -~1 flash succession frequency of the light sources. The flash succession frequency obtainable at the present time with the V-MOS-controlled light emitting diodes is about 10 NHz. When using laser light sources, substantially higher framing rates can be obtained.
In the front-light mode (fig. 4) the object 6 is sLmultaneously imaged on all video sensors 2, due to the beam-splitting effect of the mirror pyramid. The optical, mechanical and electrical arrangement of the optoelectronic recording system 1, 2, 3 of the camera according to fig. 1 and 2, respectively, ~ ~in~
unchanged. After the starting pulse and depending on the kind of the object after initiating the event by the object trigger signal generated by the sequencer or after a object trigger signal given to the sequencer from the object, a seguential activation of the shutter means 7 of the video sensors occurs, controlled by the sequencer 11. The image sequence obtAine~ in 3 ~
8 : :
this way is taken over by the image memory 8 and is stored due ~.
$o the trigger signal subsequently generated by the sequencer 11 .
The ~-~i framing rate of the camera in the front-light mode is dependent on the ~i n 1 shutter interval of the video sensors 2. The shortest shutter interval obtainable at the :
present time is abol-t 0.1 ms correspo~ing to a maximum framing ~-rate of 10 kHz (without temporary overlapping). At short shutter intervals, the ob~ect must be illuminated to a greater extent. Substantially higher f. ing rates without proportionally increased illumination can, however, be realized by a layout of each of the video sensors 2 with an image intensifier taking charge of the shut$er function.
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Electronic high speed camera with an optoelectronic recording system with a plurality of separate semiconductor video sensors (2) connected to assigned image memories (8) and with an optical imaging system imaging the image of an object on the video sensors (2) and comprising a camera objective (3) common to the video sensors (2) and a mirror pyramid (1) facing the camera objective (3) with its tip and lying with its axis in the optical axis of the camera objective (3), wherein the video sensors are arranged in a circle around the optical axis of the objective (3) and wherein the mirror pyramid (1) comprises a plurality of mirror surfaces each assigned to one of the video sensors (2), to each video sensor an electronic shutter means (7) being assigned.
2. Electronic high-speed camera according to claim 1, wherein under developing a backlight camera an optical backlight system (5a, 5b) is arranged in series before the camera objective (3), the object will be arranged in the beam path of the backlight system, and a plurality of lumped flashlight sources (4) are arranged in a circle before the optical backlight system (5a, 5b) and each can be imaged by the optical backlight system and by the camera objective (3) on one of the mirror surfaces of the mirror pyramid (1), wherein the shutter means (7) are synchronized with the flashlight sources (4).
3. Electronic high speed camera according to claim 2, wherein the flashlight sources (4) are pulse-operated light emitting diodes.
4. Electronic high speed camera according to claim 2, wherein the flashlight sources (4) are pulse-operated laser diodes.
5. Electronic high speed camera according to claim 2, 3 or 4 wherein the flashlight sources (4) are synchronized with the image memories (8).
6. Electronic high-speed camera according to one of claims 1 to 5, wherein the video sensors (2) are synchronized with each other and with the image memories (8).
7. Electronic high-speed camera according to one of claims 1 to 6, wherein the shutter means (7) are asynchronously triggerable.
8. Electronic high-speed camera according to one of claims 1 to 7, wherein the shutter means (7) are designed as gated image intensifiers connected in series with the video sensors (2).
9. Electronic high-speed camera according to one of claims 1 to 8, wherein the shutter means (7) are synchronized with the image memories (8).
10. Electronic high-speed camera according to one of claims 1 to 9, wherein the image memories (8) are connected to an image processor (9).
11. Electronic high-speed camera according to one of claims 1 to 10, wherein to the shutter means (7), the image memories (8) and in back-light mode the flashlight sources (4) a freely programmable sequencer (11) controlling the same is connected.
12. Electronic high-speed camera according to one of claims 1 to 11, wherein the video sensors (2) are aligned with the mirror surfaces of the mirror pyramid (1) and are turned around their beam path axes.
13. Electronic high-speed camera according to one of claims 1 to 11, wherein the optical imaging system comprises deflection mirrors (12) disposed in the beam paths between the mirror surfaces of the mirror pyramid (1) and the video sensors (2).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4212271.6 | 1992-04-11 | ||
| DE4212271A DE4212271C1 (en) | 1992-04-11 | 1992-04-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2111200A1 CA2111200A1 (en) | 1993-10-12 |
| CA2111200C true CA2111200C (en) | 1998-10-13 |
Family
ID=6456668
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002111200A Expired - Fee Related CA2111200C (en) | 1992-04-11 | 1993-03-23 | Electronic high-speed camera |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0589002B1 (en) |
| JP (1) | JPH06511126A (en) |
| KR (1) | KR970009136B1 (en) |
| AT (1) | ATE119301T1 (en) |
| CA (1) | CA2111200C (en) |
| DE (2) | DE4212271C1 (en) |
| WO (1) | WO1993021560A1 (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2284273B (en) * | 1993-11-29 | 1997-01-08 | Hadland Photonics Limited | Electronic high speed camera incorporating a beam splitter |
| DE4408072C2 (en) * | 1994-02-01 | 1997-11-20 | Deutsche Forsch Luft Raumfahrt | Use of an electronic high-speed camera in a method for determining flow velocities in a flow |
| IT1271647B (en) * | 1994-05-06 | 1997-06-04 | Bts Srl | HIGH-FREQUENCY CAMERA OF PHOTOGRAM AND RELATED METHOD OF MANUFACTURE |
| FR2812408B1 (en) | 2000-07-27 | 2003-10-03 | Cit Alcatel | MODULAR INTERFEROMETRIC RECOMBINATION DEVICE AND BEAM SEPARATOR FOR CONSTITUTING THE SAME |
| US7777199B2 (en) | 2004-09-17 | 2010-08-17 | Wichita State University | System and method for capturing image sequences at ultra-high framing rates |
| DE102009029321B4 (en) | 2009-09-09 | 2013-07-04 | Deutsches Zentrum für Luft- und Raumfahrt e.V. | Method and device for videographic recording of fast processes |
| US9485495B2 (en) | 2010-08-09 | 2016-11-01 | Qualcomm Incorporated | Autofocus for stereo images |
| US9438889B2 (en) | 2011-09-21 | 2016-09-06 | Qualcomm Incorporated | System and method for improving methods of manufacturing stereoscopic image sensors |
| US9398264B2 (en) | 2012-10-19 | 2016-07-19 | Qualcomm Incorporated | Multi-camera system using folded optics |
| US10178373B2 (en) | 2013-08-16 | 2019-01-08 | Qualcomm Incorporated | Stereo yaw correction using autofocus feedback |
| US9383550B2 (en) | 2014-04-04 | 2016-07-05 | Qualcomm Incorporated | Auto-focus in low-profile folded optics multi-camera system |
| US9374516B2 (en) | 2014-04-04 | 2016-06-21 | Qualcomm Incorporated | Auto-focus in low-profile folded optics multi-camera system |
| US10013764B2 (en) | 2014-06-19 | 2018-07-03 | Qualcomm Incorporated | Local adaptive histogram equalization |
| US9294672B2 (en) | 2014-06-20 | 2016-03-22 | Qualcomm Incorporated | Multi-camera system using folded optics free from parallax and tilt artifacts |
| US9549107B2 (en) | 2014-06-20 | 2017-01-17 | Qualcomm Incorporated | Autofocus for folded optic array cameras |
| US9541740B2 (en) | 2014-06-20 | 2017-01-10 | Qualcomm Incorporated | Folded optic array camera using refractive prisms |
| US9819863B2 (en) | 2014-06-20 | 2017-11-14 | Qualcomm Incorporated | Wide field of view array camera for hemispheric and spherical imaging |
| US9386222B2 (en) | 2014-06-20 | 2016-07-05 | Qualcomm Incorporated | Multi-camera system using folded optics free from parallax artifacts |
| CN104730855A (en) * | 2014-08-08 | 2015-06-24 | 中国空气动力研究与发展中心超高速空气动力研究所 | Superspeed sequence laser shadow imaging device based on beam split pyramid type |
| US9832381B2 (en) | 2014-10-31 | 2017-11-28 | Qualcomm Incorporated | Optical image stabilization for thin cameras |
| RU193299U1 (en) * | 2019-07-12 | 2019-10-22 | Общество с ограниченной ответственностью "Научно-производственное предприятие НАНОСКАН" | DEVICE FOR SPEED REGISTRATION OF IMAGES |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3449758A (en) * | 1967-10-09 | 1969-06-10 | Arthur A Lavine | High speed photographic recorder |
| DE2460625C2 (en) * | 1974-12-20 | 1983-10-27 | Siemens AG, 1000 Berlin und 8000 München | Device for electronic image recording |
| JP2510768B2 (en) * | 1990-07-05 | 1996-06-26 | 学校法人近畿大学 | Video camera for high-speed flow field measurement |
| JPH0474071A (en) * | 1990-07-13 | 1992-03-09 | Ricoh Co Ltd | Solid-state image pickup device |
| DE4041543C2 (en) * | 1990-12-22 | 1994-06-30 | Goedecke Ag | Stabilization of ascorbic acid in strongly acidic solution |
| DE4041564C1 (en) * | 1990-12-22 | 1992-06-25 | Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften Ev, 3400 Goettingen, De | Fully electronic transmitted light high speed camera - has number of solid state LED outputs which are directed by lens onto object |
-
1992
- 1992-04-11 DE DE4212271A patent/DE4212271C1/de not_active Revoked
-
1993
- 1993-03-23 EP EP93906434A patent/EP0589002B1/en not_active Revoked
- 1993-03-23 KR KR1019930703826A patent/KR970009136B1/en not_active IP Right Cessation
- 1993-03-23 AT AT93906434T patent/ATE119301T1/en not_active IP Right Cessation
- 1993-03-23 WO PCT/DE1993/000266 patent/WO1993021560A1/en not_active Application Discontinuation
- 1993-03-23 JP JP5517899A patent/JPH06511126A/en active Pending
- 1993-03-23 CA CA002111200A patent/CA2111200C/en not_active Expired - Fee Related
- 1993-03-23 DE DE59300098T patent/DE59300098D1/en not_active Revoked
Also Published As
| Publication number | Publication date |
|---|---|
| DE4212271C1 (en) | 1993-07-08 |
| KR970009136B1 (en) | 1997-06-05 |
| JPH06511126A (en) | 1994-12-08 |
| WO1993021560A1 (en) | 1993-10-28 |
| CA2111200A1 (en) | 1993-10-12 |
| DE59300098D1 (en) | 1995-04-06 |
| EP0589002B1 (en) | 1995-03-01 |
| EP0589002A1 (en) | 1994-03-30 |
| KR940701553A (en) | 1994-05-28 |
| ATE119301T1 (en) | 1995-03-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed | ||
| MKLA | Lapsed |
Effective date: 20010323 |