IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`In re Patent of:
`
`Lebens et al.
`
`U.S. Patent No.: 6,488,390
`
`
`
`Issue Date:
`
`December 3, 2002
`
`Appl. Serial No.: 09/978,760
`
`Filing Date:
`
`October 16, 2001
`
`Title:
`
`COLOR-ADJUSTED CAMERA LIGHT AND METHOD
`
`
`
`
`
`
`
`PETITION FOR INTER PARTES REVIEW OF UNITED STATES PATENT
`
`NO. 6,488,390 PURSUANT TO 35 U.S.C. §§ 311–319, 37 C.F.R. § 42
`
`
`
`
`
`Exhibit LG-1005
`
`U.S. Patent No. 5,010,412 (“Garriss”)
`
`
`
`
`

`

`United States Patent
`
`{19]
`
`[11] Patent Number:
`
`5,010,412
`
`
`Garriss
`[45] Date of Patent:
`Apr. 23, 1991
`
`{54] HIGH FREQUENCY, Low POWER LIGHT
`SOURCE FOR VIDEO CAMERA
`
`
`6/1987 McDermott et a1. ........... 362/240
`4,677,533
`
`4,882,498 11/1989 Cochran et a1.
`...... 250/571
`
`75
`
`Inventor: Gregory M. Carries, Federal Wa ,
`Wash.
`1
`[
`y
`[73] Assignee: The Boeing Company, Seattie, Wash.
`[2;] App]. No.: 290,581
`_
`Dec. 27' 1988
`[22] Fded’
`[51]
`Int. (15 ......................... HMN 3/12; H04N 7/ 18'
`[52] US. 0.
`...................... 358/240; 358/107;
`356/23; 354/ 129; 354/132
`[58] Field of Search ............... 358/107, 125,. 212, 240,
`353/241. lm; 356/23; 352/3. 11, 300; 354/129.
`132, 140. 414
`
`[55]
`
`References Cited
`.
`U'S‘ PATENT DOCUMENTS
`3,737,722
`6/1973 Schmuck ............................ 315/209
`318/480
`3,800,204 3/1974 Kenny
`
`362/104
`4,161,018 7/1979 Briggs .........
`‘
`.. 362/103
`8/1979 Milleretal.
`4.164.003
`
`1.... 313/33
`4,211,933 7/1930 Ray
`
`4,264,845 4/1981 Bednm ..
`315/323
`4.298.869 11/1981 Okuno
`340/782
`4,459,645 7/ 1984 Glatter ................................ 362/104
`
`mm“? Examiner—John K- P9113
`Attorney, Agent, or Firm—Dellett, Smith-Hill & Bedell
`[57]
`ABSTRACT
`A strobe light provides uniformly intense, monochro-
`matic illumination of an object photographed by a video
`camera. The strobe light includes a circuit board having
`a central aperture and a plurality of lightvemitting di-
`odes mounted. on the circuit board and generally sur-
`rounding the aperture. The circuit board is attached to
`the camera with the aperture positioned in front of the
`camera lens such that the video camera views the object
`through the aperture as the diodes illuminate the object.
`The strobe light further includes an oscillator providing
`an output square wave signal of adjustable frequency
`and duty cycle. A transistor switch controlled by the
`square wave signal periodically connects a constant
`voltage across the diodes, thereby causing the diodes
`simultaneously to generate flashes of light with a fre-
`q"uency and duty cycle determined by the square wave
`signal.
`
`13 Claims, 2 Drawing Sheets
`
`11
`
`
`
`Exhibit LG-1005 Page 1
`
`LGELEM0002957
`
`Exhibit LG-1005 Page 1
`
`

`

`US. Patent
`
`Apr. 23, 1991
`
`Sheet 1 of 2
`
`5,010,412
`
`11
`
`Exhibit LG-1005 Page 2
`
`LGELEM0002958
`
`Exhibit LG-1005 Page 2
`
`

`

`US. Patent
`
`Apr. 23, 1991
`
`Sheet 2 of 2
`
`5,010,412
`
`DRIVER
`
`FIG. 3
`
`CIRCUIT
`4o STROBE
`
`SIGNAL
`
`76
`r\- -.
`I
`'
`I
`I
`——l—-
`I
`I
`
`L-- .1 H
`
`32
`
`74
`
`78
`
`2
`
`72
`
`v
`
`v
`
`v
`
`FIG. 4
`
`Exhibit LG-1005 Page 3
`
`LGELEM0002959
`
`Exhibit LG-1005 Page 3
`
`

`

`1
`
`5,010,412
`
`2
`
`HIGH FREQUENCY, LOW POWER LIGHT
`SOURCE FOR VIDEO CAMERA
`
`BACKGROUND OF THE INVENTION
`
`5
`
`graphed by a video camera includes a plurality of
`. monochromatic light-emitting diodes (LEDs) mounted
`on a surface of a circuit board or the like having a cen-
`tral aperture, with the diodes generally disposed in
`surrounding relation to said aperture. The LEDs are
`thereby arranged and directed in a pattern providing
`uniform illumination of the object. The circuit board is
`attached to the video camera such that the video cam-
`era views the object through the aforementioned aper-
`ture.
`In accordance with a feature of the invention, an
`oscillator supplies an output signal of adjustable fre-
`quency and duty cycle and this oscillator output signal
`controls operation of a switch connecting a regulated
`voltage source to the aforementioned LEDs, causing
`the LEDs to generate pulses of uniformly intense,
`monochromatic light. In accordance with a further
`aspect of the} invention, the oscillator operates when
`enabled by a synchronizing signal, produced by the
`camera, indicating when the camera starts acquiring an
`image. The LEDs are energized only when the camera
`is acquiring an image, minimizing the load of the strobe
`light on its power source such as, for example, the cam-
`era battery.
`It is accordingly an object of the present invention to
`provide an improved light source that generates uni-
`formly intense, monochromatic pulses of light over a
`range of frequencies and duty cycles.
`It is another object of the present invention to pro-
`vide an improved strobe light that is light weight and
`efficient, and operates from a low voltage power
`source.
`
`The present invention relates to light sources and in
`particular to a high frequency, low power light source
`employing light emitting diodes for illuminating an
`object photographed by a portable video camera.
`Inspection system sometimes employ a video camera
`to produce video signals representing light intensity at
`regularly spaced points on the surface of an object, for
`example a machine part'to be engaged by an industrial
`robot. When a “frame grabber" converts the video
`signals into gray scale bit map data, a control computer
`can analyze the bit map data and determine the shape
`and position of the part. Some inspection systems use a
`variable frequency strobe light for illuminating a rotat-
`ing or oscillating machine part monitored by the video
`camera to provide data representing the object as it
`appears at one or more selected positions during mo-
`tion.
`.
`'
`It is usually preferable that a light source uniformly
`illuminate a part under inspection. For example, if ambi-
`ent light casts non-uniform shadows on the part, the
`camera can be fitted with a narrow band light filter for
`filtering out wavelengths of light other than the band of
`the light spectrum produced by the monochromatic
`light source. Since the intensity of ambient light “noise”
`within the narrow band is negligibly small compared
`with the intensity of the source, the ambient light inter-
`feres less with the monitoring process.
`The light source should be light weight and rugged.
`It should require minimal maintenance, provide uniform
`illumination, generate little electrical noise or heat, and
`should not require a power source different from the
`one operating the camera. Incandescent, xenon, and
`fluorescent lights have been used as light sources, but
`have been found inconvenient or unacceptable in some
`applications because they require large, high voltage
`power supplies or generate too much heat or electrical
`noise. Such prior art light systems may also be too
`heavy or too fragile or may not be able to operate at a
`sufficiently high frequency or sufficiently low duty
`cycle.
`Fiber optic ring lights provide a low infrared, uni-
`form'circle of light, but require a high intensity incan-
`descent
`lamp as a source illuminator. The lamp is
`housed in a separate unit, and light is transmitted down
`a large diameter fiber optic cable to the ring light. The
`illuminator housings typically are very large in compar-
`ison to the ring light, require frequent replacement of
`the inth lamp, and generate large amounts of
`heat. In addition, the fiber optic cable coupling the lamp
`housing to the ring light is prone to internal fracturing
`due to the normal motions of a robotic end effector,
`requiring replacement. Fluorescent and cold cathode
`ring lights eliminate some of the above drawbacks in
`that they are lightweight, generate minimal amounts of
`heat, and are uniform. However, problems inherent
`with these types of light sources are their requirement
`of a high voltage (>200 V.) power supply, mechanical
`fragility and low light output.
`SUMMARY OF THE INVENTION
`
`In accordance with an embodiment of the present
`invention, a light source for providing uniformly in-
`tense, monochromatic illumination of an object photo-
`
`10
`
`.
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`It is a further object of the invention to provide an
`improved strobe light
`that is rugged, requires little
`maintenance and generates little electrical noise or heat.
`The subject matter of the present invention is particu-
`larly pointed out and distinctly claimed in the conclud-
`ing portion of this specification. However, both the
`organization and method of operation of the invention,
`together with further advantages and objects thereof,
`may best be understood by reference to the following
`description taken with the accompanying drawings
`wherein like reference characters refer to like elements.
`
`BRIEF DESCRIPTION OF THE DRAWING
`
`FIG. I is an elevational view of a strobe light flash
`assembly in accordance with the present invention as
`mounted on a video camera;
`FIG. 2 is a front view of the strobe light flash assem-
`bly of FIG. 1;
`FIG. 3 is a combination block and schematic diagram
`of a strobe light in accordance with the present inven-
`tion; and
`FIG. 4 is a schematic diagram of the driver circuit of
`FIG. 3.
`'
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`60
`
`Referring to FIGS. 1 through 3, a light source in
`accordance with the present invention includes a flash
`assembly 10 mounted upon a circuit board 12 having a
`central aperture 14. A set of light-emitting diodes
`(Him) 16 and resistors 18 are positioned on circuit
`65 board 12 in surrounding relation to the aperture, while
`a protective, transparent plutic cap 20 suitably covers
`circuit board 12, LEDs 16 and resistors 18. Microstrip
`conductors on circuit board 12 connect LEDs 16 in
`
`Exhibit LG-1005 Page 4
`
`LGELEM0002960
`
`Exhibit LG-1005 Page 4
`
`

`

`5,010,412
`
`3
`series with resistors 18 between terminals 22 on the
`underside of the board. When a strobe signal pulse is
`applied across terminals 22, LEDs 16 generate a flash of
`light. The flash assembly 10 is desirably mounted on the
`housing 28' of a video camera 24 by means of supports
`27, with lens 26 cf camera 24 being positioned behind
`aperture 14 whereby camera 24 can record an image of
`an object 11 well illuminated by the flash from LEDs
`16.
`
`A driver circuit 40 which may be installed within
`housing 28 of camera ,24 generates a strobe signal ap-
`plied to the terminals 22 via a connector cable 30 ex-
`tending between flash assembly 10 and camera housing
`28. Pushbuttons 31 and 32 mounted on housing 28 can
`be employed to permit a user to select whether the
`strobe signal driving LEDs 16 is synchronized to cam-
`era operation and whether it is continuous or an oscillat-
`ing square wave. When the strobe signal is continuous,
`the LEDs steadily illuminate object 11. When the strobe
`signal oscillates, the LEDs periodically flash to illumi-
`nate object 11 with a frequency and duty cycle as may
`be controlled by knobs 33 and 34 also mounted on cam-
`era housing 28.
`Camera 24 generates video signals representing the
`light intensity at regularly spaced points on the surface
`of object 11 as illuminated by diodes 16. These signals
`may, for example, be conveyed via an extemal cable 36
`to a conventional “frame grabber” (not shown) for
`converting the video signals into gray scale bit map
`data. A computer can analyze the bit map data output of
`the frame grabber and determine the shape and position
`of illuminated object 11. In an alternative embodiment,
`a frame grabber may be mounted within camera hous-
`ing 28. and in such embodiment cable 36 conveys the bit
`map data from the frame grabber to a computer.
`Referring in'particular to FIG. 3, twelve sets of four
`LEDs 16 mounted on circuit board 12 are each con-
`
`nected in series with separate resistors 18 between ter-
`minals 22 of the flash assembly. As illustrated in FIG. 2,
`the sets of four LEDs, each comprising a square array,
`are uniformly spaced around board 12 and are posi-
`tioned for illuminating an object “seen” by the camera.
`The driver circuit 40, energized by a regulated dc.
`voltage source 42 (+V) suitably powered from a typi-
`cal camera power supply mounted within the camera
`housing 28, provides the strobe signal across terminals
`22. One terminal of driver circuit 40 is grounded to
`housing 28 while another input terminal of driver cir-
`cuit 40 receives a synchronizing signal (SYNC) from
`the camera.
`.
`Referring to FIG. 4, the driver circuit 40 comprises a
`switch 50 Controlled by the aforementioned push button
`31 mounted on the camera housing. One contact 50a of
`switch 50 selectively connects regulated voltage source
`+V directly to a circuit node 52. Another contact 50b
`selectively couples the synchronizing output signal of
`the camera to the base of npn transistor 51. The collec-
`tor of transistor 51 is tied to +V while the emitter
`thereof is connected to node 52. Variable resistor 54
`controlled by knob 33 of FIG. 1 is connected between
`node 52 and a node 56. In series therewith is another
`variable resistor 58 controlled by knob 34 of FIG. 1 and
`deposed between nodes 56 and 60 respectively con-
`nected to terminal 7, and to terminals 2 and 6, of a con—
`ventional type 555 timing circuit 64. A capacitor 62
`returns node 60 to ground to complete a time constant
`circuit. Output pin 3 of timer 64 drives the base of a pnp
`transistor 66 through a resistor 68, also coupled to the
`
`4
`center of a biasing voltage divider comprising resistors
`70 and 72 connected between +V and ground. A resis—
`tor 74 returns the collector of transistor 66 to ground,
`while a switch 76 operated by push button 32 of FIG. 1
`selectively grounds the emitter of transistor 66 through
`resistor 78. The output of driver circuit 40 is derived
`between +V and the emitter of transistor 66.
`When a user wishes the strobe light to illuminate
`object 11 continuously, he closes switch 76 by operating
`push button 32, thereby causing current to flow from
`the +V voltage source to ground via diodes 16 and
`resistors 18 of FIG. 3 and resistor 78 of FIG. 4. For
`stroboscopic flash operation, the user opens switch 76
`via push button 32 to the position shown and adjusts
`switch 50 using push button 31 to select the appropriate
`synchronizing mode. In one selected position of switch
`50, contact 50a closes, connecting the +V voltage
`source to node 52, while contact 506 Opens. When ener-
`gized, timer 64 acts as an oscillator continuously pro-
`ducing a square wave signal at pin 3 of frequency and
`duty cycle respectively controlled by the settings of
`resistors 54 and 58.
`The square wave output signal at pin 3 turns transis—
`tor 66 on and off. When transistor 66 turns on, current
`flows from source +V to ground through diodes 16 and
`resistors 18 of FIG. 3 and through transistor 66 of FIG.
`4. As the current flows through diodes 16,
`it causes
`them to emit. light, but when transistor 66 turns off,
`current ceases to flow through the diodes. Thus, diodes
`16 generate pulses or flashes of light with a frequency
`and duty cycle determined by the square wave output
`of the timer 64 which the user may adjust using knobs
`33 and 34 respectively.
`When the operator selects a second position of switch
`50, contact 501) closes to the position shown and contact
`50a opens to the position shown. Contact 501) then cou-
`ples the synchronizing output signal of the camera to
`the base of transistor 51. The camera’s synchronizing
`means 41 drives the synchronizing signal high when
`acquiring an image and drives the synchronizing signal
`low when it is not acquiring an image. For example, the
`video element of a typical video camera comprises an
`array of charge-coupled devices (CCDs) each receiving
`light reflected by a separate area of the object being
`monitored by the camera. When light strikes such a
`charge coupled device element, it stores charge in pro-
`portion to the intensity and duration of light. After
`allowing light to strike the CCD array for a short per-
`iod, the charge distribution on the array represents the
`light intensity distribution as monitored by the camera
`and after thus capturing the image on the CCD array,
`the camera generates a video signal by shifting the
`charges out of the array and converting them to a se-
`quence of voltages proportional to the charges. The
`camera repeats operations of storing charges in the
`CCD array and shifting them out, thereby providing a
`video signal representing a sequence of images. The
`frame grabber digitizes the video signal to produce bit
`map data.
`While the camera is capturing an image by allowing
`charge to build up on the CCD array,
`the camera’s
`synchronizing means drives its output synchronizing
`signal high. This signal is normally used to synchronize
`operations of the video camera and the frame grabber or
`other device such as a video recorder receiving the
`video signal output of the camera. In the present circuit,
`this synchronizing signal also turns on transistor 51 of
`FIG. 4, with switch contact 501: closed, thereby cou-
`
`_ 5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`'
`45
`
`55
`
`60
`
`65
`
`Exhibit LG-1005 Page 5
`
`LGELEM0002961
`
`Exhibit LG-1005 Page 5
`
`

`

`5
`
`5,010,412
`
`15
`
`25
`
`pling voltage source +V to node 52 and causing timer
`64 to operate. Timer 64 produces a square wave signal
`at pin 3 initially synchronized with the sync signal from
`the camera and oscillating with frequency and duty
`cycle controlled by resistors 54 and 58. The square
`wave signal turns transistor 66 on and off for periodi-
`cally energizing the LEDs as the video camera is ac-
`quiring an image. The timer 64 can alternatively be set
`to provide_ only one high frequency sciuare wave half
`cycle at pin 3, to generate one flash timed with each 10
`camera sync pulse. When the camera is subsequently .
`_ busy shifting charges out of the CCD array, the camera
`drives its output synchronizing signal low, and as the '
`synchronizing signal goes low, it turns off transistor 51
`of FIG. 4 for disconnecting the +V source from node
`52. The output of timer 64 goes low, shutting off transis-
`tor. 66 and preventing current from flowing through the
`LEDs. Thus, the strobe light only flashes when the
`camera is'capturing an image and does not flash when
`the camera is processing data, minimizing the drain of 20
`the camera battery 44 of FIG. 3.
`The strobe light of the present invention provides
`uniformly intense, monochromatic illumination of an
`object photographed by 'a video camera system. Timer
`64 can flash the LEDs at frequencies (and correspond-
`ingly short pulse widths) up to 10 MHz, as opposed to
`30—100 KHz maximum frequency of xenon strobe
`lights. The frequency and duty cycle of the strobe light
`are accurately controllable over wide ranges. Switch-
`ing the lights at a high frequency, low duty cycle rate
`advantageously increases the light output by raising the
`current level while the minimized duty cycle prevents
`heating of the diodes and moderately improves diode
`life. Unlike laser or incandescent strobe lights, the LED
`strobe light is rugged, light weight and efficient, and
`operates'from a low voltage power source. The strobe
`light of the present invention also requires little mainte—
`nance and generates little electrical noise or heat. Its
`regulated power supply controls available current, sta-
`bilizing the oscillator and light output thereof, and al-
`lowing operation from a camera power supply.
`While a preferred embodiment of the present inven-
`tion has been shown and described, it will be apparent
`to those skilled in the art that many changes and modifi-
`cations may be made without departing from the inven-
`tion in its broader aspects. The appended claims are
`therefore intended to cover all such changes and modi-
`fications as fall within the true spirit and scope of the
`invention.
`I claim:
`
`35
`
`45
`
`1. A light source for providing illumination of an
`object, said light source comprising:
`a diode for emitting light when energized;
`means for periodically energizing said diode with an 1
`55
`adjustable frequency and duty cycle such that said
`diode emits a sequence of light flashes illuminating
`said object; and .
`enabling means for selectively enabling and disabling
`said means for periodically energizing said diode,
`said enabling means being operatively responsive
`to a synchronization signal.
`2. A light source for providing illumination of an
`object, said light source comprising:
`a diode for emitting light when energized; and
`means for periodically energizing said diode with an
`adjustable frequency and duty cycle such that said
`diode emits a sequence of light flashes illuminating
`said object;
`
`65
`
`6
`wherein said means for periodically energizing said
`diode comprises oscillator means for providing an
`oscillating output signal of adjustable frequency
`and duty cycle with the frequency being adjusted
`g in accordance with a magnitude of an input fre-
`quency control value and the duty cycle being
`adjusted in accordance with the magnitude of an
`input duty cycle control value, means for generat-
`ing a constant supply voltage, and switch means
`operated by said oscillating signal for periodically
`coupling Said supply voltage to said diode with a
`frequency and duty cycle determined by the fre-
`quency and duty cycle of the oscillator output
`signal, said supply voltage energizing said diode
`such that said diode emits said light flashes.
`3. A light source for providing monochromatic illum-
`ination of an object photographed by a camera acquir-
`ing an image of the object through a lens, the light
`source comprising:
`a plurality of diodes for emitting light when ener-
`Bind;
`means for attaching said diodes to said camera with
`said diodes arranged about said lens and directed
`for illuminating said object, and
`means for periodically energizing said diodes.
`4. The apparatus in accordance with claim 3 wherein
`said camera is adapted to produce a synchronizing sig-
`nal substantially concurrent with operation thereof, and
`including means controlling said energizing means and
`responsive to said synchronizing signal for energizing
`said diode when said camera is acquiring an image.
`5. The apparatus in accordance with claim 3 wherein
`said means for energizing said diodes comprises:
`oscillator means for providing an oscillating output
`signal of predetermined frequency and duty cycle;
`means for providing a supply voltage;
`switch means operated by said oscillating signal for
`periodically coupling said supply voltage to said
`diodes with a frequency and duty cycle determined
`by the frequency and duty cycle of the oscillator
`output signal, said supply energizing said diodes
`such that said diodes concurrently and periodically
`illuminate said object.
`6. A strobe light for providing uniformly intense,
`monochromatic illumination of an object photographed
`by a video camera acquiring a sequence of images of the
`object through a lens and asserting a synchronizing
`signal indicating when it is acquiring an image,
`the
`strobe light comprising:
`a plurality of diodes mounted on the video camera
`generally surrounding the lens, the diodes generat—
`ing light of similar wavelength when energized by
`a supply source, the intensity of light generated by
`the diodes being determined by a voltage magni»
`tude of said supply source;
`oscillator means responsive to said synchronizing
`signal for providing an output of adjustable fre-
`quency and duty cycle when said synchronizing
`signal indicates said video camera is acquiring an
`image, the frequency being adjusted in accordance
`with a magnitude of an input frequency control
`value, and the duty cycle being adjusted in accor-
`dance with the magnitude of an input duty cycle
`control value;
`means providing a supply source for energizing said
`diodes; and
`switch means operated by said oscillating signal for
`, periodically coupling said supply source to said
`
`Exhibit LG-1005 Page 6
`
`LGELEM0002962
`
`Exhibit LG-1005 Page 6
`
`

`

`5,010,412
`
`v
`
`5
`
`10
`
`20
`
`8
`7
`the duty cycle being adjusted in accordance with
`diodes with afrequency and duty cycle determined
`the magnitude of an input duty cycle control value;
`by the frequency and duty cycle of the oscillator
`means for generating a Constant voltage supply sig-
`output signal to cause diodes simultaneously to
`nal; and
`generate pulses of light.
`switch means operated by said oscillating signal for
`7.7 A strobe light for providing uniformly intense,
`periodically coupling said supply signal
`to said
`monochromatic illumination of an object photographed
`diodes with a frequency and duty cycle determined
`by a video camera acquiring a sequence of images of the
`by the frequency and duty cycle of the oscillator
`object,
`the Video camera generating a synchronizing
`output signal, said supply signal energizing said
`signal
`indicating when it is acquiring an image,
`the
`diodes such that said diodes concurrently emit
`strobe light comprising:
`light.
`a support having an aperture;
`10. The apparatus in accordance with claim 8
`a plurality of diodes mounted on said support and
`wherein said camera comprises a video camera includ-
`generally surrounding the aperture in a pattern
`ing means
`for generating a synchronizing signal
`providing substantially uniform illumination of the
`object when said support is in juxtaposition with 15 wherein said means for concurrently energizing said
`said object, the diodes generating light of similar
`diodes comprises:
`wavelength when energized by a supply signal, the
`oscillator means responsive to said synchronizing
`intensity of light generated by the diodes being
`signal for providing an output signal when said
`determined by a voltage magnitude of the supply
`synchronizing signal indicates said video camera is
`signal;
`,
`acquiring said image;
`means for attaching said support to the camera such
`means for generating a constant voltage supply; and
`that the video camera views the object through the '
`switch means operated by said oscillating signal for
`aperture as said diodes illuminate said object;
`'
`periodically coupling said supply to said diodes
`oscillator means responsive to said synchronizing
`with a frequency and duty cycle determined by the
`signal for providing an oscillating output signal of 25
`frequency and duty cycle of the oscillator output
`adjustable frequency and duty cycle When said
`signal.
`‘
`synchronizing signal indicates said video camera is
`11. A method for illuminating an object photo-
`acquiring an image, the frequency being adjusted in
`graphed by a camera acquiring an image of the object
`accordance with a magnitude of an input frequency
`through a lens, the method comprising the steps of:
`control value, and the duty cycle being adjusted in 30
`generally surrounding said lens with a plurality of
`accordance with the magnitude of an input duty
`diodes that emit light when energized such that
`cycle control value;
`said light illuminates said object; and
`a voltage source for generating an output voltage
`periodically energizing said diodes.
`signal;
`'
`12. A method for providing monochromatic strobo-
`means for regulating said output voltage signal to 35 scopic illumination of an object photographed by a
`produce a said supply signal of substantially con-
`video camera acquiring a sequence of images of the
`stant voltage;
`object through a lens, the video camera generating a
`switch means operated by said oscillating signal for
`synchronizing signal indicating image acquisition, the
`periodically applying said supply signal
`to said
`method comprising the steps of:
`diodes with afrequency and duty cycle determined 40
`generally surrounding said lens with a plurality of
`by the frequency and duty cycle of the oscillator
`diodes that emit light when energized by a supply
`output signal, said supply signal causing said diodes
`signal, said diodes being positioned such that their
`to generate light simultaneously;
`emitted light illuminates said object, the intensity
`first means responsive to user input for generating
`of light generated by the diodes being determined
`said frequency control value; and
`by a voltages magnitude of the supply signal;
`second means responsive to user input for generating
`providing an oscillating output signal of predeter-
`said duty cycle control value.
`'
`mined frequency and duty cycle when said syn-
`8. An apparatus for photographing an object, 'com-
`chronizing signal indicates said video camera is
`prising;
`acquiring an image; and
`a camera for acquiring an image of the object through so
`applying said supply signal to said diodes in response
`a lenswhen said object is illuminated;
`to said oscillating output signal with a frequency
`a plurality of diodes for emitting light when ener-
`and duty cycle determined by the frequency and
`gized;
`duty cycle of the oscillating output signal, said
`means for attaching said diodes to said camera with
`supply signal causing said diodes to generate pulses
`said diodes substantially uniformly distributed 55
`of light.
`about said lens, such that when energized, said
`13. A light source for providing illumination of an
`diodes illuminate said object with substantially
`object, said light source comprising:
`uniform light intensity; and
`a diode for emitting light when energized;
`means for concurrently energizing said diodes.
`means for periodically energizing said diode such that
`9. The apparatus in accordance with claim 8 wherein 60
`said diode emits a sequence of light flashes illumi-
`said means for concurrently energizing said diodes com-
`nating said object; and
`prises:
`enabling means for selectively enabling and disabling
`oscillator means for providing an oscillating output
`said means for periodically energizing said diode,
`signal of adjustable frequency and duty cycle, the
`said enabling means being operatively responsive
`frequency being adjusted in accordance with a 65
`to a camera synchronization signal.
`magnitude of an input frequency control value, and
`‘
`‘
`‘
`‘
`‘
`
`»
`
`45 .
`
`Exhibit LG-1005 Page 7
`
`LGELEM0002963
`
`Exhibit LG-1005 Page 7
`
`