High speed stroboscope system for visually observing dynamic properties by moving objects of various characteristics

• US 4,948,247 A
• Filed: 09/21/1988
• Issued: 08/14/1990
• Est. Priority Date: 09/21/1988
• Status: Expired due to Term

• Current Assignee: Laitram LLC
• Original Assignee: Laitram LLC
• Inventors: Lapeyre, James M.
• Primary Examiner(s): Rosenberger, Richard A.
• Application Number:
  US07/247,269
• Time in Patent Office: 692 Days
• Field of Search: 356/23, 350/523, 350/525
• US Class Current: 356/23
• CPC Class Codes: G01P 3/40 using stroboscopic means
• CPC Class Codes: G01S 17/89 for mapping or imaging

Abstract

An improved stroboscopic system permits higher response speeds in the order of nanoseconds and a richness of control fatures for highlighting different viewing surfaces including pulse flash length control in addition to frequency, color control, light emitting area control and light focussing features for concentration of available light on the viewing field. Thus, new applications such as the viewing the movement of selected portions of the surface of a high frequency piezoelectric responsive crystal structure are now possible. This is achieved by flashing at least one solid state light emitting element that produces light in an emitting area defined by the shape of a light emitting surface activated in response to externally derived synchronization pulses. Thus, when directed upon a field of view on a movable object and relating the synchronization pulses to the movement of the object within that viewing field, the illusion is produced that the moving object in at least a portion of the field of view receiving the emitted light from the solid state element is stationary to the human view, permitting detailed study of surface shapes and dynamic reactions in frequency ranges far above those viewable with prior art strobing methods. Provisions are made for positioning the light flash sources very close to the viewing surface without interference with a visible line of site. One embodiment provides microscopic viewing and photography of the strobed field of view.

Claims

1. An improved stroboscope system comprising in combination,

solid state light emitting means responsive to emit light over discrete time durations defined by the presence of input activating pulses of a predetermined duration,

strobing control means providing said input activating pulses to said light emitting means timed to occur in response to synchronizing signals to produce light flashes having a duration substantially that of the activating pulses,

means for directing said light flashes onto a movable object with a light intensity permitting an observer to view a moving part of the object in a movable phase thereof related to the synchronization pulses as if stationary comprising a patterned array of individual light emitting elements and means for processing said activating pulses to predetermined ones of the elements in said array, and

control means for separately programming different subsets of the individual elements to emit light in response to said input activating pulses in different respective patterns on said movable object.

2. The stroboscope system of claim 1 wherein different light emitting elements in said array emit light of different colors and including means for superimposing different strobe light colors simultaneously in different observation regions of said movable object.

3. The stroboscope system of claim 1 further comprising means operable with said strobing control means to flash individual light emitting elements for emitting light of one predetermined color over selected patterned regions on the movable object.

4. The stroboscope system of claim 1 wherein said light emitting elements include optical lens means for focussing emitted light from a plurality of light emitting elements in said array onto a predetermined viewing site disposed adjacent said array.

5. The system of claim 1, wherein the light emitting elements are LEDs and further comprising a viewing site for placement of the moving object with the array of LEDs positioned closely to the viewing site to produce a substantial portion of the light energy emitted thereby at the moving object.

6. The system of claim 5 further comprising means interspersing the pattern of LEDs in said array with transparent regions permitting a direct view of the moving object when being strobed.

7. The system of claim 1 further comprising viewing means interspersed in said array with said individual light emitting elements for visually observing the movable object when lighted by said light flashes.

8. The system of claim 1 wherein individual elements for emitting light of different colors are patterned in said array to produce strobing by flashes of different colors and further comprising control means for programming light flashes of the individual elements of particular colors to control the light color produced for strobing said movable object.

9. The system of claim 1 further comprising aperiodic strobing control means for producing said synchronizing signals repetitively from the movable object to provide a continuing repetitive view of movement in the movable object.

10. The system of claim 1 further comprising periodic strobing control means operable to produce said light flashes at frequencies above five million herz.

11. The system of claim 1 further comprising variable control means for operating said solid state light emitting means at a selected variable frequency of pulse repetition rate over a range of light flash pulse durations.

12. The system of claim 1 further comprising a microscope for viewing a movable object position lighted by the light flashes from said array arranged at a position circumferentially adjacent to a viewing lens of the microscope.

13. The system of claim 12 further comprising means positioning said light emitting means array adjacent said movable object to move together with a microscope viewing lens for lighting the field of view of the microscope with said light flashes.

14. The method of stroboscopically viewing a movable object as defined in claim 1 further comprising the steps of:

positioning the movable object with a portion thereof in the field of view of a microscope, and

lighting said object portion with strobe light flashes from said emitting means array disposed to move together with a viewing lens of the microscope.

15. An improved stroboscopic system as defined in claim 1 having means for producing on a moving object in response to a sequence of recurring actuation pulses flashes of different predetermined light colors emitted from a subset of the plurality of the light emitters in said array to eliminate the moving object with a flash pattern established by said subset and timed in relationship to movements of the object to produce the illusion that at least a portion of the moving object is stationary to the human view and means for selecting flashes from different subsets of light emitters to produce different desired colors and emitters of illumination.

16. The method of strobing a moving object to view it as if stationary in a recurring phase of movement thereof comprising the steps of:

repetitively exciting a selected subset of a plurality of electronically actuated solid state light emitting elements positioned in a patterned array of such elements to produce a sequence of light flashes in a patterned emitting area thereby defined for lighting by the solid state characteristics of the light emitting elements and activated at synchronized times determined by a sequence of synchronization pulses derived as a function of movement of said moving object, directing the emitted light from said light emitting array upon a field of view on a movable object, and relating the synchronization pulses to the recurring phases of movement of the object within that field of view to produce the illusion that the moving object in a portion of the field of view receiving the pattern of emitted light from said selected subset of elements is stationary to the human view.

17. An improved stroboscopic system having means for producing on a predetermined region of a moving surface area presented by a moving object in response to selective control of recurring light flashes produced at a subset plurality of spaced light emitting positions defining said region selected from an array defining a set of said positions and timed to produce in said region of the surface area the illusion to the human view that the regional portion of the moving object surface area lighted by the flashes is stationary.

18. The improved strobing method of viewing a selected pattern portion of a moving surface area of variable shape for dynamic motion analysis by providing a recurring light flash pattern produced by selective flashing of patterned subsets of an array of LED light emitting elements directed to illuminate said selected pattern portion at repetitive times synchronized with movements on said surface area for producing the illusion that motion of the surface area in the selected pattern portion is stationary.

19. An improved stroboscopic system having means for positioning light emitting means for producing recurring strobe light flashes over an emission surface area positioned in close proximity to a moving surface to illuminate a field of view thereon wherein the light emitting means region resides in a position interfering with a direct view of the illuminated field of view on the moving surface, and means apportioning the emission surface area into light producing regions interspersed by transparent regions permitting a direct view of the moving surface while being strobed.

20. The improved stroboscopic method of electronically selecting from a patterned array of light producing elemental areas different subsets of elemental areas to produce recurring flashes of light directed onto a moving object to form different lighted patterns at a timing related to the movement of the object for providing the illusion to the human view that at least a portion of the moving object presented for human viewing by said lighted pattern is stationary.

21. An improved electronic strobing system, comprising in combination, a matrix array of light producing elemental areas for directing light flashes from the elemental areas upon a moving object for stroboscopic examination, and selective control means for producing light flashes from various subcombinations of the elemental areas as different lighted patterns on the moving object timed to make at least a portion of the moving object visible to the human view within the lighted pattern to appear stationary.