CA2089356A1 - Surveillance apparatus particularly for use in viewing vehicle number-plates - Google Patents
Surveillance apparatus particularly for use in viewing vehicle number-platesInfo
- Publication number
- CA2089356A1 CA2089356A1 CA002089356A CA2089356A CA2089356A1 CA 2089356 A1 CA2089356 A1 CA 2089356A1 CA 002089356 A CA002089356 A CA 002089356A CA 2089356 A CA2089356 A CA 2089356A CA 2089356 A1 CA2089356 A1 CA 2089356A1
- Authority
- CA
- Canada
- Prior art keywords
- camera
- light
- illuminator
- pulses
- plates
- 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.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/01—Detecting movement of traffic to be counted or controlled
- G08G1/017—Detecting movement of traffic to be counted or controlled identifying vehicles
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/01—Detecting movement of traffic to be counted or controlled
- G08G1/052—Detecting movement of traffic to be counted or controlled with provision for determining speed or overspeed
- G08G1/054—Detecting movement of traffic to be counted or controlled with provision for determining speed or overspeed photographing overspeeding vehicles
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/01—Detecting movement of traffic to be counted or controlled
- G08G1/017—Detecting movement of traffic to be counted or controlled identifying vehicles
- G08G1/0175—Detecting movement of traffic to be counted or controlled identifying vehicles by photographing vehicles, e.g. when violating traffic rules
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/01—Detecting movement of traffic to be counted or controlled
- G08G1/042—Detecting movement of traffic to be counted or controlled using inductive or magnetic detectors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Studio Devices (AREA)
- Stroboscope Apparatuses (AREA)
- Traffic Control Systems (AREA)
- Closed-Circuit Television Systems (AREA)
Abstract
A surveillance apparatus, particularly for viewing vehicle number plates in covert, night operations, comprises an illuminator (10) having an array of light-emitting diodes (11) or a source of laser light, and a shuttered, preferably-miniature TV camera. The illuminator emits a series of high-peak pulses of infrared light (17) outside the range visible to the human eye, which reflect from a number plate (13) to be received by the camera which operates in synchronism with the illuminator. It is preferred to have the illuminator (10) positioned close to the camera lens (15) to minimise the included angle (.THETA.) between incident light (17) and reflected light (16).
Description
-........ WV 92/03808 PCI/GB91/01405 2~g93 ' ~- r-~iE~;~,~'C.:.i~RA r~!C ?.~r~TI'~'L~RL'. _-~R [~Sr _~ . -VT~,~G VEHICLr ~.UMBER-~L~TES
: ', -~.is _-ventlon relates ~o survelilance a~Daratus ~hich `a ~ar~_^_larl intended ~or use .. v~ewin~ ven cle -.umDer-?lates in covert night-survelllance operations.
, T~e viewing or reading of vehicle numDer-plates at night in a covert manner has long been a problem. Additional visible il1umination is usuall~i unacce~table or unavail-able, (exceDt possiblv in .he orm of _treet lights n some situations) and the traditional inrra-red illumi-nator whic~. operates by ~iltering the output cf ~n incan--descent source, can be seen by many people even when -~
- 830nm short-wavelength cut filters are employed.
Further, in order to image a front number-plate when the vehicle headlights are switched on, a considerable - amount of additional illumir~ation is required if the number plate is to be read clearly or at all.
, T ~ is an objec- of t~.e 2resent invention to provide an apparatus for reading vehicle number-plates, particu-larly in a covert ~,anner ~uring night-survelllance, in ~lhich the above-mentioned problems are overcome or at least reduced.
~ccor~ing to the p-esent invention, there is provided a surveillance a~paratus comprising an illuminator for emitting a series of high-energy pulses of light, and a camera oper~ting in synchronism with the illumina-tor to receive said p- ses of light. In covert night-surveillance o~erations, as in vie~7ing vehlcle number-?lates, this light is infra-red light outside the range visible to the humlan eve; in the infra-red (IR) ranye of the spect~um, light is invisible to he human eve at 940nm or S80nm or possibl~ 820nm, and light-radlation ~f t~ese ~avelengths can be ~rovided bv suitable LED
or iaser sources.
W092/03808 PCT/GB91/nl4n~
- 20~35~
. --Preferably, saia illuminatGr comprises an array of light-emitting diodes (LEDs) or a source or laser light, and said camera comprises a shuttered Tv camera which will usually be of minlature si~e.
The illuminator and the (miniature) camera may be combined in a small package, which is attractive to covert sur-veillance operations, and it is preferred to position tAe illuminator close to the camera lens so as to minimise the included angle between incident and reflect~d light.
The use of (invisible) IR light not only avoids detectlon of the surveillance operation, but also reduces the counter-effect which may be produced by the headlamps of the vehicle being observed, and this effect is further reduced by providing the camera with a bandpass filter and reducing the 'open' period of the camera.
If the TV camera is of t:~e (usual) kind which receives visible light, it is desirable to provide for adjustable back-focus to accommodate the difference between- the - focal points of the camera lens for visible light and for IR light.
Embodiments of the present invention will now be -described, by way of example, with reference to the accompanying drawings in which: ;
' ' .
Figure 1 is a graph showing ~um) wavelengths of light emitted from a conventional incandescent light source having a filament temperature of about 3000K, : . :
Figure 2 is a similar graph showlng the wavelengths ` of (I.R.) light emitted 'rom a 340nm illuminator;
f and, ~' :
. .
W092/03808 2 ~ ~ 9 3 5 ~ PCT/GB91/01405 ! .
~igure 3 is a diagramatic view showing apparatus according .o the ?resent invenrion for viewing or reading vehicle ~umber-plates, ana illustrating the operation of the ~-apparatus.
' ~' .
Re~errlng firstly to Figures 1 and 2 of the drawlngs, it will be noted tha. the light energy transmitted from a source 10 such as the 3000K bulb (Figu-e 1) contains -a substantial degree of visible light, and some IR light.
On the other hand, when LEDs are employed, the light energv is conventionall~ in the range o_ about 840 to 1000nm; LEDs suitable for the present invention have a centre wavelength of 940nm or 880nm, with a spectral width of, typical-ly, 50nm (Figure 2).
' The apparatus accorcing to the present invention comprises the illuminator or light-energy source 10 which, suitably, has an array of standard 940nm LEDs transmitting IR light which is invisible to the human eye, as indic:.ted above with reference to Figure 2~ The array may comprise about 40 to 400 LEDs, depending on the required specification of the apparatus, and one LED which has proved saticrac-tory is the AEG TSIP5201 having a continuous rat.ing of 'C~OmA.
~. .
A camera 12 is employed in conjunction ~:rth the LED illum-inator, in viewing a car number-plate 13, and has electri-cal connection 14 with the illuminator. The camera com-prises a shuttered TV came~a having a CCD sensor whic~
is sensitive to IR light, behind a lens unit 15, and records and/or transmits to a possibly- mot~ TV m~ni.tor (not s~.own) video signals derived f~om he lllumi;;ation of the number-plate by the LED arrav 11. A 'shuttered' TV camera has an integratior. time (Whi1^ ?ictur- i;.form-ation is being accumulatea) which is shorter _han its ~ield period. Shuttering mav be achievea electron ~all~
or mechani lly, or ~y means of an elec~-o-optical shut-ter, but i~ !S preferable .-~at the shuttering operation , WO 92/038~8 2 ~ 8 3 3 ~ 6 PCT/CB91/014~5 - e _ .
' a silent, as occurs -~ith electronic shuttering. The standard ,0 per second, field periods for a (U.~.) TV
_amera are 20mS, out the camera mav be shuttered to 1mS or each field which Jould result in the camera -egisterina only 1/20 of the total light-energv rom a broadband continuous source operating for 20mS.
~owever, when used in conjunction with an LED illuminator which produces energy in high-peak pulses which are synchronized with the camera "open" periods, the camera can receive a comparable amount of energy during each shuttering period. In the present embodiment of the invention, the aforementioned LEDs TSIP5201 have a cont-inuous ratins of lOOmA, but the driving circuits in the illuminator 10 feed high-energy pulses of about 1000mA, or possibly more, at a rate of 50 pulses per second ~ith each pulse having a duration of 1mS; as a result, the camera receives at least 50% of the energy from broadband illumination without the restriction oi shuttering. A rate of 60 pulses per second would be appropriate if, for example, U.S. system TV monitors ~ere to be employed with U.S. system cameras (12).
It is to be noted that the focal point of any lens, _or IR light, lies behind the focal point for visible iight. In order to achieve sharp focussing when employ-lng a TV camera which also receives visible light, it is desirable to be able to change the back-focus of the camera. The PEARPOINT P176 camera is particularly suitable for use in the apparatus of the present invent-ion, as it incorporates motorised back-focus which facil-itates initial set up for each operation; this camera also provides high sensitivity, extended IR sensitivitv Up tO 11 Odnm, high resolution and a selectable (on/off) shutter.
, In operation, therefore, the LEDs emit Aish enersy due .o high-peak lOOOmA pulses cf ~ duration of about lmS
- W092/03808 2 0 o ~ 3 5 ~ PCT/GB91/01~05 ~ 5 ~
in synchronism ~ith the cameras "open" periods of 1mS.
This illumination is sufflcient for reading car number-?iates at night, under normal conditions. The disadvan-tage -~hich car headlamps can cause is substantially reaucea as the level or energy received bv the camera from the steady light produced by the headlamps during each period of lmS, effectively of chopped waveform, is much less than the energy level received during those periods from the high-peak pulses generated by the LEDs.
To reduce even further the effect of car headlamps, a band-pass filter may be introduced into the optical path 16 to the camera; this filter is centered on the peak output wavelength of the LEDs (in the IR band) and has a bandwidth which passes most of the LED energy but rejects light of other wavelengths such as the remai-ning energy emitted from the broadband vehicle headlamps.
As an alternative to the LED illuminator described, it is possible to employ a source of laser light which, although more expensive than LEDs, would allow a much narrower bandpass filter to be used which could reduce still further the counter-effect of headlamp illumina-tion. When employing laser light, which usually has a wavelength of about 820nm, the possibility of visibil-ity from certain viewpoints cannot be ignored, but the small chance of detection is regarded as an acceptable risk. It should be noted that a person with exceptional eyesight could, in certain circumstances, detect IR
light of 880nm or conceivably longer wavelength, but again this is regarded as an acceptable risk. -According to a further feature of the invention, the light energy fed to the camera by the LED ?ulses can be changed on a field-by-field basis, to provide images or the number-plate ~hich 1ill then appear brighter or dimmer. These images are proauced at very short :` ~
W092/03808 2 ~ ~ 9 3 ~ 6 PCT/GB91~01405 .
nter~als or time, anà mav subsequentl~ be selected ~o ~acilitate the reading or a number-plate which may oe ~nclear _ue tO poor -erlec~ it~ aused by, for e:~am-?le, dirt or ~he plate. ~he camera ill usuallf nave a f~ ed !ris, anà the puise enerqy may De changed by varying amplitude or duration, and it is to be noted that reduction of duration, say from lmS in stages to 0.3mS, has the added advantage of reducing possible blurring caused by movement o~ the vehicle. Similarly, the camera shuttering time may be chanaea on a field-bv-field basis, to reduce yet further the counter-effect of headlamps.
Vehicle number-plates (12) in many countrles including U.K. are of a type which give very high reflectance, provided that the llluminator 10 and camera 12 are very close together. As shown in Figure 3, appropriate arrange-ment of the illuminator array 11 and the camera lens can reduce below 5 the included angle ~ between the incident beam 17 and the reflecteà beam 16. This narrow angle can result in a reduction in the amount of illumination required.
The apparatus is useful in viewing vehicle number-plates during the dark, and also during dawn and dusk, and may operate continuously to cover daylight hours. It ~ill be appreciated that, for davlight use, and also in non-covert operations such as traffic surveys, the .
question of visibility may be of little importance and pulsed illuminators in the spectral bands of wavelengths shorter than IR may be employed.
' ,:
Yet a further advantage of the apparatus of the present invention is that the illuminator anà TV camera can be of small size' possiblv packageà 'n the form o_ 2 cube having sides of the order of 100mm. The power required for the LED il-luminator may be as low as 7 or 8 watts and, operating at 12 volts, permits battery operation.
.
.~ ~
: ', -~.is _-ventlon relates ~o survelilance a~Daratus ~hich `a ~ar~_^_larl intended ~or use .. v~ewin~ ven cle -.umDer-?lates in covert night-survelllance operations.
, T~e viewing or reading of vehicle numDer-plates at night in a covert manner has long been a problem. Additional visible il1umination is usuall~i unacce~table or unavail-able, (exceDt possiblv in .he orm of _treet lights n some situations) and the traditional inrra-red illumi-nator whic~. operates by ~iltering the output cf ~n incan--descent source, can be seen by many people even when -~
- 830nm short-wavelength cut filters are employed.
Further, in order to image a front number-plate when the vehicle headlights are switched on, a considerable - amount of additional illumir~ation is required if the number plate is to be read clearly or at all.
, T ~ is an objec- of t~.e 2resent invention to provide an apparatus for reading vehicle number-plates, particu-larly in a covert ~,anner ~uring night-survelllance, in ~lhich the above-mentioned problems are overcome or at least reduced.
~ccor~ing to the p-esent invention, there is provided a surveillance a~paratus comprising an illuminator for emitting a series of high-energy pulses of light, and a camera oper~ting in synchronism with the illumina-tor to receive said p- ses of light. In covert night-surveillance o~erations, as in vie~7ing vehlcle number-?lates, this light is infra-red light outside the range visible to the humlan eve; in the infra-red (IR) ranye of the spect~um, light is invisible to he human eve at 940nm or S80nm or possibl~ 820nm, and light-radlation ~f t~ese ~avelengths can be ~rovided bv suitable LED
or iaser sources.
W092/03808 PCT/GB91/nl4n~
- 20~35~
. --Preferably, saia illuminatGr comprises an array of light-emitting diodes (LEDs) or a source or laser light, and said camera comprises a shuttered Tv camera which will usually be of minlature si~e.
The illuminator and the (miniature) camera may be combined in a small package, which is attractive to covert sur-veillance operations, and it is preferred to position tAe illuminator close to the camera lens so as to minimise the included angle between incident and reflect~d light.
The use of (invisible) IR light not only avoids detectlon of the surveillance operation, but also reduces the counter-effect which may be produced by the headlamps of the vehicle being observed, and this effect is further reduced by providing the camera with a bandpass filter and reducing the 'open' period of the camera.
If the TV camera is of t:~e (usual) kind which receives visible light, it is desirable to provide for adjustable back-focus to accommodate the difference between- the - focal points of the camera lens for visible light and for IR light.
Embodiments of the present invention will now be -described, by way of example, with reference to the accompanying drawings in which: ;
' ' .
Figure 1 is a graph showing ~um) wavelengths of light emitted from a conventional incandescent light source having a filament temperature of about 3000K, : . :
Figure 2 is a similar graph showlng the wavelengths ` of (I.R.) light emitted 'rom a 340nm illuminator;
f and, ~' :
. .
W092/03808 2 ~ ~ 9 3 5 ~ PCT/GB91/01405 ! .
~igure 3 is a diagramatic view showing apparatus according .o the ?resent invenrion for viewing or reading vehicle ~umber-plates, ana illustrating the operation of the ~-apparatus.
' ~' .
Re~errlng firstly to Figures 1 and 2 of the drawlngs, it will be noted tha. the light energy transmitted from a source 10 such as the 3000K bulb (Figu-e 1) contains -a substantial degree of visible light, and some IR light.
On the other hand, when LEDs are employed, the light energv is conventionall~ in the range o_ about 840 to 1000nm; LEDs suitable for the present invention have a centre wavelength of 940nm or 880nm, with a spectral width of, typical-ly, 50nm (Figure 2).
' The apparatus accorcing to the present invention comprises the illuminator or light-energy source 10 which, suitably, has an array of standard 940nm LEDs transmitting IR light which is invisible to the human eye, as indic:.ted above with reference to Figure 2~ The array may comprise about 40 to 400 LEDs, depending on the required specification of the apparatus, and one LED which has proved saticrac-tory is the AEG TSIP5201 having a continuous rat.ing of 'C~OmA.
~. .
A camera 12 is employed in conjunction ~:rth the LED illum-inator, in viewing a car number-plate 13, and has electri-cal connection 14 with the illuminator. The camera com-prises a shuttered TV came~a having a CCD sensor whic~
is sensitive to IR light, behind a lens unit 15, and records and/or transmits to a possibly- mot~ TV m~ni.tor (not s~.own) video signals derived f~om he lllumi;;ation of the number-plate by the LED arrav 11. A 'shuttered' TV camera has an integratior. time (Whi1^ ?ictur- i;.form-ation is being accumulatea) which is shorter _han its ~ield period. Shuttering mav be achievea electron ~all~
or mechani lly, or ~y means of an elec~-o-optical shut-ter, but i~ !S preferable .-~at the shuttering operation , WO 92/038~8 2 ~ 8 3 3 ~ 6 PCT/CB91/014~5 - e _ .
' a silent, as occurs -~ith electronic shuttering. The standard ,0 per second, field periods for a (U.~.) TV
_amera are 20mS, out the camera mav be shuttered to 1mS or each field which Jould result in the camera -egisterina only 1/20 of the total light-energv rom a broadband continuous source operating for 20mS.
~owever, when used in conjunction with an LED illuminator which produces energy in high-peak pulses which are synchronized with the camera "open" periods, the camera can receive a comparable amount of energy during each shuttering period. In the present embodiment of the invention, the aforementioned LEDs TSIP5201 have a cont-inuous ratins of lOOmA, but the driving circuits in the illuminator 10 feed high-energy pulses of about 1000mA, or possibly more, at a rate of 50 pulses per second ~ith each pulse having a duration of 1mS; as a result, the camera receives at least 50% of the energy from broadband illumination without the restriction oi shuttering. A rate of 60 pulses per second would be appropriate if, for example, U.S. system TV monitors ~ere to be employed with U.S. system cameras (12).
It is to be noted that the focal point of any lens, _or IR light, lies behind the focal point for visible iight. In order to achieve sharp focussing when employ-lng a TV camera which also receives visible light, it is desirable to be able to change the back-focus of the camera. The PEARPOINT P176 camera is particularly suitable for use in the apparatus of the present invent-ion, as it incorporates motorised back-focus which facil-itates initial set up for each operation; this camera also provides high sensitivity, extended IR sensitivitv Up tO 11 Odnm, high resolution and a selectable (on/off) shutter.
, In operation, therefore, the LEDs emit Aish enersy due .o high-peak lOOOmA pulses cf ~ duration of about lmS
- W092/03808 2 0 o ~ 3 5 ~ PCT/GB91/01~05 ~ 5 ~
in synchronism ~ith the cameras "open" periods of 1mS.
This illumination is sufflcient for reading car number-?iates at night, under normal conditions. The disadvan-tage -~hich car headlamps can cause is substantially reaucea as the level or energy received bv the camera from the steady light produced by the headlamps during each period of lmS, effectively of chopped waveform, is much less than the energy level received during those periods from the high-peak pulses generated by the LEDs.
To reduce even further the effect of car headlamps, a band-pass filter may be introduced into the optical path 16 to the camera; this filter is centered on the peak output wavelength of the LEDs (in the IR band) and has a bandwidth which passes most of the LED energy but rejects light of other wavelengths such as the remai-ning energy emitted from the broadband vehicle headlamps.
As an alternative to the LED illuminator described, it is possible to employ a source of laser light which, although more expensive than LEDs, would allow a much narrower bandpass filter to be used which could reduce still further the counter-effect of headlamp illumina-tion. When employing laser light, which usually has a wavelength of about 820nm, the possibility of visibil-ity from certain viewpoints cannot be ignored, but the small chance of detection is regarded as an acceptable risk. It should be noted that a person with exceptional eyesight could, in certain circumstances, detect IR
light of 880nm or conceivably longer wavelength, but again this is regarded as an acceptable risk. -According to a further feature of the invention, the light energy fed to the camera by the LED ?ulses can be changed on a field-by-field basis, to provide images or the number-plate ~hich 1ill then appear brighter or dimmer. These images are proauced at very short :` ~
W092/03808 2 ~ ~ 9 3 ~ 6 PCT/GB91~01405 .
nter~als or time, anà mav subsequentl~ be selected ~o ~acilitate the reading or a number-plate which may oe ~nclear _ue tO poor -erlec~ it~ aused by, for e:~am-?le, dirt or ~he plate. ~he camera ill usuallf nave a f~ ed !ris, anà the puise enerqy may De changed by varying amplitude or duration, and it is to be noted that reduction of duration, say from lmS in stages to 0.3mS, has the added advantage of reducing possible blurring caused by movement o~ the vehicle. Similarly, the camera shuttering time may be chanaea on a field-bv-field basis, to reduce yet further the counter-effect of headlamps.
Vehicle number-plates (12) in many countrles including U.K. are of a type which give very high reflectance, provided that the llluminator 10 and camera 12 are very close together. As shown in Figure 3, appropriate arrange-ment of the illuminator array 11 and the camera lens can reduce below 5 the included angle ~ between the incident beam 17 and the reflecteà beam 16. This narrow angle can result in a reduction in the amount of illumination required.
The apparatus is useful in viewing vehicle number-plates during the dark, and also during dawn and dusk, and may operate continuously to cover daylight hours. It ~ill be appreciated that, for davlight use, and also in non-covert operations such as traffic surveys, the .
question of visibility may be of little importance and pulsed illuminators in the spectral bands of wavelengths shorter than IR may be employed.
' ,:
Yet a further advantage of the apparatus of the present invention is that the illuminator anà TV camera can be of small size' possiblv packageà 'n the form o_ 2 cube having sides of the order of 100mm. The power required for the LED il-luminator may be as low as 7 or 8 watts and, operating at 12 volts, permits battery operation.
.
.~ ~
Claims (12)
1. A surveillance apparatus comprising an illuminator for emitting a series of high-peak power pulses of light, and a camera operating in synchronism with the illuminator to receive the pulses of light after reflection from an object being observed.
2. An apparatus for viewing vehicle number plates in covert night-surveillance operations, comprising an illuminator for emitting a series of high-peak power pulses of infra-red light outside the range visible to the human eye, and a camera operating in synchronism with the illuminator to receive the pulses of infra-red light after reflection from a number plate.
3. An apparatus as claimed in Claim 2, in which said camera is provided with a bandpass filter to reduce counter-effects produced by headlamps of the vehicle being observed.
4. An apparatus as claimed in any preceding Claim, in which said illuminator comprises an array of light-emitting diodes.
5. An apparatus as claimed in Claim 4, in which said array comprises between 40 and 400 940nm light-emitting diodes.
6. An apparatus as claimed in any of Claims 1 to 3, in which said illuminator comprises a source of laser light.
7. An apparatus as claimed in any preceding Claim, in which said camera is a miniature camera, and said illuminator and the miniature camera are combined in a small package.
8. An apparatus as claimed in any preceding Claim, in which said illuminator is positioned close to the camera lens so as to minimise the included angle between incident and reflected light.
9. An apparatus as claimed in any preceding Claim, in which said camera comprises a shuttered T.V. camera.
10. An apparatus as claimed in Claim 9, in which means are provided for varying the duration of said high-peak pulses of light, and means are provided for effecting corresponding adjustment of the shuttering of said camera on a field-by-field basis, to control the brightness of images derived from the camera.
11. An apparatus as claimed in any preceding Claim, in which means are provided for varying the intensity of said high-peak power pulses of light, on a field-by-field basis, to control the brightness of images derived from the camera.
12. An apparatus for viewing vehicle number-plates, substantially as hereinbefore described with reference to the accompanying drawings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB909018174A GB9018174D0 (en) | 1990-08-17 | 1990-08-17 | Apparatus for reading vehicle number-plates |
| GB9018174.4 | 1990-08-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2089356A1 true CA2089356A1 (en) | 1992-02-18 |
Family
ID=10680886
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002089356A Abandoned CA2089356A1 (en) | 1990-08-17 | 1991-08-19 | Surveillance apparatus particularly for use in viewing vehicle number-plates |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0543904A1 (en) |
| JP (1) | JPH06503662A (en) |
| KR (1) | KR930701801A (en) |
| AU (1) | AU8409091A (en) |
| BR (1) | BR9106764A (en) |
| CA (1) | CA2089356A1 (en) |
| FI (1) | FI930681A (en) |
| GB (3) | GB9018174D0 (en) |
| HK (1) | HK1007042A1 (en) |
| WO (1) | WO1992003808A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2257257A (en) * | 1991-06-21 | 1993-01-06 | Christopher Ian Hughes | Security apparatus |
| DE4225074C1 (en) * | 1992-07-29 | 1994-02-03 | Nsm Ag | Device for controlling the closure of a CCD camera exposed to light by a light source |
| SE503707C2 (en) * | 1994-10-24 | 1996-08-05 | Combitech Traffic Syst Ab | Device for identification of vehicles at a checkpoint |
| FR2749117B1 (en) * | 1996-05-21 | 1998-07-31 | Christophel Claude | VIDEO CAMERA ESPECIALLY FOR REMOTE SURVEILLANCE |
| JP2000339589A (en) | 1999-05-25 | 2000-12-08 | Fujitsu Ltd | Traffic safety auxiliary system for vehicle and recording medium |
| GB2354898B (en) * | 1999-07-07 | 2003-07-23 | Pearpoint Ltd | Vehicle licence plate imaging |
| FR2797081B1 (en) * | 1999-07-29 | 2002-10-31 | Positive | METHOD FOR IDENTIFYING A LICENSE MOTOR VEHICLE AND APPARATUS FOR IDENTIFYING MOTOR VEHICLE THEREOF |
| GB9927623D0 (en) * | 1999-11-24 | 2000-01-19 | Koninkl Philips Electronics Nv | Illumination source |
| US6832728B2 (en) | 2001-03-26 | 2004-12-21 | Pips Technology, Inc. | Remote indicia reading system |
| WO2003009251A1 (en) * | 2001-07-18 | 2003-01-30 | Hyunjae Tech Co., Ltd | System for automatic recognizing licence number of other vehicles on observation vehicles and method thereof |
| EP1419478A1 (en) | 2001-08-16 | 2004-05-19 | Optidtech Optical Identification Technologies Ltd. | Electro-optic reader for retro-reflective bar codes |
| DE10205250B4 (en) * | 2002-02-08 | 2006-11-09 | Funkwerk Plettac Electronic Gmbh | Optical band-stop filter and electronic surveillance camera with such a filter |
| US6902299B2 (en) | 2003-02-27 | 2005-06-07 | Cantronic Systems Inc. | Long distance illuminator |
| GB2404107A (en) * | 2003-07-16 | 2005-01-19 | British Broadcasting Corp | Flash-based keying |
| RU2431774C2 (en) * | 2006-09-25 | 2011-10-20 | Тони МЭЙЕР | Floodlight with fringe micro relief for observation system |
| US8218822B2 (en) | 2007-05-14 | 2012-07-10 | Pips Technology, Inc. | Apparatus and method for recognizing the state of origin of a vehicle license plate |
| EP2186337A4 (en) * | 2007-08-08 | 2011-09-28 | Tony Mayer | Non-retro-reflective license plate imaging system |
| DE102007049637B4 (en) * | 2007-10-17 | 2015-10-15 | Audi Ag | Method for operating a lighting system and an image acquisition system of a vehicle and object detection system for a vehicle |
| EP3206046B1 (en) | 2007-12-21 | 2021-08-25 | Leddartech Inc. | Detection and ranging methods and systems |
| EP2517189B1 (en) | 2009-12-22 | 2014-03-19 | Leddartech Inc. | Active 3d monitoring system for traffic detection |
| GB201012178D0 (en) * | 2010-07-20 | 2010-09-01 | Telemactics Technology Llp | Indicia identifying system |
| US8908159B2 (en) | 2011-05-11 | 2014-12-09 | Leddartech Inc. | Multiple-field-of-view scannerless optical rangefinder in high ambient background light |
| WO2012172526A1 (en) | 2011-06-17 | 2012-12-20 | Leddartech Inc. | System and method for traffic side detection and characterization |
| EP2820632B8 (en) | 2012-03-02 | 2017-07-26 | Leddartech Inc. | System and method for multipurpose traffic detection and characterization |
| JP6938371B2 (en) | 2014-09-09 | 2021-09-22 | レッダーテック インコーポレイテッド | Discretization of detection zones |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1192499B (en) * | 1982-08-30 | 1988-04-13 | Fiorello Sodi | APPARATUS FOR DETECTION AND REGISTRATION OF ROAD INFRINGEMENTS, WITH THE USE OF LIGHT-TYPE ENERGY IN THE CONTIGUOUS TO THE VISIBLE BANDS |
| GB2142738A (en) * | 1983-07-02 | 1985-01-23 | Shirley Developments Limited | Stroboscope |
| DE3404396A1 (en) * | 1984-02-08 | 1985-08-14 | Dornier Gmbh, 7990 Friedrichshafen | DEVICE AND METHOD FOR TAKING DISTANCE IMAGES |
| FR2571506B1 (en) * | 1984-10-05 | 1987-01-23 | Trt Telecom Radio Electr | SEMI-ACTIVE NIGHT OBSERVATION SYSTEM WITH LIGHT INTENSIFICATION |
| EP0181412A1 (en) * | 1984-11-10 | 1986-05-21 | Tele-Security-Foto Überwachungsanlagen GmbH | Television image pick-up system |
| AU6121886A (en) * | 1985-06-25 | 1987-01-30 | Matsushita Electric Works Ltd. | Monitoring device applying noctovision for a doorphone system |
| IT1221607B (en) * | 1987-08-25 | 1990-07-12 | Fiorello Sodi | SYSTEM FOR THE DETECTION AND REGISTRATION OF INFRINGEMENTS TO THE RULES OF THE ROAD DISCIPLINE, WITH THE USE OF LASER |
| GB2212689B (en) * | 1987-11-17 | 1992-01-02 | Ferranti Plc | Television camera system |
-
1990
- 1990-08-17 GB GB909018174A patent/GB9018174D0/en active Pending
-
1991
- 1991-08-19 EP EP91915142A patent/EP0543904A1/en not_active Withdrawn
- 1991-08-19 AU AU84090/91A patent/AU8409091A/en not_active Abandoned
- 1991-08-19 BR BR919106764A patent/BR9106764A/en not_active Application Discontinuation
- 1991-08-19 JP JP3513975A patent/JPH06503662A/en active Pending
- 1991-08-19 WO PCT/GB1991/001405 patent/WO1992003808A1/en not_active Application Discontinuation
- 1991-08-19 GB GB9117967A patent/GB2248994B/en not_active Expired - Lifetime
- 1991-08-19 CA CA002089356A patent/CA2089356A1/en not_active Abandoned
-
1993
- 1993-02-03 GB GB939302128A patent/GB9302128D0/en active Pending
- 1993-02-16 FI FI930681A patent/FI930681A/en unknown
- 1993-02-17 KR KR1019930700452A patent/KR930701801A/en not_active Application Discontinuation
-
1998
- 1998-06-23 HK HK98106135A patent/HK1007042A1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0543904A1 (en) | 1993-06-02 |
| AU8409091A (en) | 1992-03-17 |
| FI930681A0 (en) | 1993-02-16 |
| WO1992003808A1 (en) | 1992-03-05 |
| HK1007042A1 (en) | 1999-03-26 |
| GB9018174D0 (en) | 1990-10-03 |
| GB9302128D0 (en) | 1993-04-28 |
| FI930681A (en) | 1993-02-16 |
| GB2248994B (en) | 1995-04-05 |
| GB2248994A (en) | 1992-04-22 |
| BR9106764A (en) | 1993-06-29 |
| KR930701801A (en) | 1993-06-12 |
| GB9117967D0 (en) | 1991-10-09 |
| JPH06503662A (en) | 1994-04-21 |
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