Monochromator and light dispersing apparatus

• US 3,922,092 A
• Filed: 12/06/1973
• Issued: 11/25/1975
• Est. Priority Date: 12/06/1973
• Status: Expired due to Term

• Current Assignee: Scientific Food Solutions, LLC
• Original Assignee: Francois J. G. Van Den Bosch
• Inventors: van den Bosch, Francois J. G.
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US05/422,421
• Time in Patent Office: 719 Days
• Field of Search: 356/99,100,101,188
• US Class Current: 356/332
• CPC Class Codes: G01J 3/12 Generating the spectrum; Monochromators
• CPC Class Codes: G01J 3/32 Investigating bands of a spectrum in sequence by a single detector

Abstract

Narrow band light spectra suitable for spectrographic analysis are generated from a wide band light spectra source by successively scanning the respective light band spectra. In one embodiment, successive rotating scanning wheels having respective apertures therein are positioned such that the desired band width spectra within the entire spectrum of interest, or a portion thereof, are scanned whereby each scan causes the light band spectra output therefrom to be narrower than the light band spectra input thereto. The positioning of the apertures may be varied as desired. The scanning members are driven synchronously. In a second embodiment, the scanning members comprise rotatable drums, each having a plurality of distinct and separate reflecting surfaces on the circumference thereof, and the successive reflections of the light spectra from one rotating drum to another produce a narrow band light spectra output from a dispersed light radiation source.

Claims

1. Apparatus for generating narrow band light spectra, comprising:

a source for generating wide band light spectra;

first means having a number of apertures and mounted to rotate in a path whereby said apertures intersect said wide band light spectra to produce first narrow band light spectra;

second means having a number of apertures and mounted to rotate in a path whereby said apertures intersect said first narrow band light spectra to produce second narrow band light spectra;

the bandwidth of said second narrow band light spectra are narrower than the bandwidth of said first narrow band light spectra; and

means for rotating said first and second means synchronously.

2. Apparatus as in claim 1 wherein said first and second means each comprise a disc-like member mounted co-axially with respect to one another.

3. Apparatus as in claim 1 further comprising an output aperture for passing said second narrow band spectra and first projection means for projecting said first narrow band light spectra to said second means and second projection means for projecting said second narrow band light spectra to said output aperture.

4. Apparatus as in claim 3 wherein said first and second means for projecting each include a lens for projecting the individual narrow band light spectra from each aperture in each of said first and second means, respectively.

5. Apparatus as in claim 1 wherein the synchronous relationship of the respective rotational velocities of said first and second means is defined by:

V1 nV2 where V1 is the rotational velocity of said second means, V2 is the rotational velocity of said first means, and n is an integer >

or = 1.

6. Apparatus as in claim 1 further comprising additional means having a number of apertures and mounted to rotate in a path whereby said apertures intersect said second narrow band light spectra to produce third narrow band light spectra and said third narrow band light spectra are narrower than said second narrow band light spectra.

7. Apparatus as in claim 1 wherein the apertures in said first and second means are located on a single-turn clockwise spiral trace of each respective first and second means.

8. Apparatus as in claim 7 wherein the apertures in each of said first and second means are in non-spaced relationship.

9. Apparatus as in claim 7 wherein the apertures in each of said first and second means are in spaced relationship to one another.

10. Apparatus as in claim 2 wherein the apertures in said first and second means are located on at least one radius of each respective first and second disc-like members.

11. Apparatus as in claim 10 wherein the apertures in each of said first and second means are in non-spaced relationship.

12. Apparatus as in claim 10 wherein the apertures in each of said first and second means are in spaced relationship to one another.

13. Apparatus for generating narrow band light spectra, comprising:

a transmission grating rotating at a given velocity for generating wide band light spectra from a source of light radiation;

a first drum-like member rotating at the same velocity as said transmission grating and including a number of reflecting mirror surfaces mounted on the circumference thereof;

a second rotating drum-like member including a number of reflecting mirror surfaces mounted on the circumference thereof;

saiD first drum-like member is mounted to reflect narrow band light spectra generated by reflection of portions of said wide band light spectra from said number of reflecting mirror surfaces onto the reflecting mirror surfaces of said second drum-like member, whereby the band-width of the narrow band light spectra reflected from the reflecting mirror surfaces of said second drum-like member are narrower than the bandwidth of the narrow band light spectra reflected from said reflecting mirror surfaces of said first drum-like member; and

means for rotating said first and second drum-like members synchronously.

14. Apparatus as in claim 13 further comprising at least one additional rotating drum-like member having a number of reflecting surfaces on the circumference thereof and mounted to reflect the narrow band light spectra from said second drum-like member for producing a narrow band light spectra output having narrower bandwidth light band spectra than the bandwidth of the narrow band light spectra reflected from said second drum-like member, and means for rotating said at least one additional rotating drum-like member in synchronism with said first and second drum-like members.

15. Apparatus as in claim 13 further comprising means for reflecting the wide band light spectra from said transmission grating to the reflecting surfaces of said first drum-like member.

16. Apparatus as in claim 14 wherein the synchronous rotational relationship of the respective first, second, and at least one additional drum-like member is defined by:

V1 nV2 V2 nV3 where V3, V2 and V1 are the respective rotational velocities of the first, second and additional drum-like member, and n and m are integers >

or = 1.