Producing Filters With Combined Transmission and/or Reflection Functions

• US 20090195852A1
• Filed: 02/04/2008
• Published: 08/06/2009
• Est. Priority Date: 02/04/2008
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Kiesel, Peter, Hegyi, Alex, Johnson, Noble M., Bassler, Michael, Beck, Markus, Buergel, Tobias
• Granted Patent: US 7,894,068 B2
• Time in Patent Office: Days
• US Class Current: 359/238
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 2021/6421 Measuring at two or more wavelengths
• CPC Class Codes: G01N 2021/6471 Special filters, filter wheel
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence

Abstract

A transmissive and/or reflective optical filter can receive input light, which can emanate from objects traveling along paths past the filter, e.g. from biological cells, viruses, colored spots or other markings on documents, and so forth. In response, the filter can provide output light in accordance with a combined transmission function that is approximately equal to a superposition or scaled superposition of a set of simpler transmission functions. The set can include two or more non-uniform transmission functions, a subset of which can be different from each other and positioned relative to each other so that the output light has time variation in accordance with each of the functions in the subset. The subset could include, for example, a random function and a periodic function, a chirp function and a periodic function, or any other suitable combination of two or more simpler functions.

Claims

1. An article of manufacture comprising:

a transmissive/reflective filter with a combined transmission function within an application'"'"'s range of photon energies, the combined transmission function being approximately equal to a superposition or scaled superposition of a set of simpler transmission functions, the set including two or more simpler non-uniform transmission functions;

in the superposition or scaled superposition, each of a subset of at least two of the simpler non-uniform transmission functions being different from each other and positioned relative to each other so that, in response to input light within the application'"'"'s range of photon energies emanating from objects traveling along any of one or more paths past the filter, the filter provides output light with time variation in accordance with each of the functions in the subset.

2. The article of claim 1 in which the filter is structured to do at least one of:

transmit the input light to provide the output light; and

reflect the input light to provide the output light.

3. The article of claim 1 in which each of the functions in the subset is one of:

a periodic function;

a random function; and

a chirp function.

4. The article of claim 3 in which the subset includes a random function and a periodic function.

5. The article of claim 3 in which the subset includes a chirp function and a periodic function.

6. The article of claim 1 in which each of the functions in the subset varies along a respective variation direction;

the functions in the subset being positioned so that their variation directions are parallel.

7. The article of claim 6 in which the functions in the subset are one-dimensional functions.

8. The article of claim 1 in which the filter'"'"'s optical thickness varies as a function of position;

the combined transmission function depending on the optical thickness.

9. The article of claim 8 in which the filter is a layered structure, the filter'"'"'s optical thickness depending on at least one of:

thickness of one or more layers in the layered structure; and

refractive index of one or more layers in the layered structure.

10. The article of claim 1 in which the article further comprises:

a detector, the detector including;

a photosensor with a photosensitive surface; and

a filter assembly on the photosensitive surface of the photosensor, the filter assembly including the transmissive/reflective filter.

11. The article of claim 10 in which the filter assembly further includes:

a transmissive multicolor filter between the photosensitive surface and the filter.

12. The article of claim 10 in which the article is one of:

a flow cytometer; and

a scanner.

13. Apparatus that can be operated in an application, the apparatus comprising:

a fluidic structure that includes a channel through which objects can travel along respective paths during operation of the apparatus; and

an encoding component;

the encoding component including a filter assembly that can receive light emanating from objects in the channel;

in response to input light that is within the application'"'"'s range of photon energies and that is emanating from an object traveling through the channel past the filter arrangement, the filter assembly providing output light;

the filter assembly including;

a filter element with a combined transmission function within the application'"'"'s range of photon energies, the combined transmission function being approximately equal to a superposition or scaled superposition of a set of two or more simpler transmission functions, the set including two or more simpler non-uniform transmission functions;

in the superposition or scaled superposition, each of a subset of at least two of the simpler non-uniform transmission functions being different from each other and positioned relative to each other so that, in response to the input light, the filter assembly provides the output light with time variation in accordance with each of the functions in the subset.

14. The apparatus of claim 13 in which the apparatus is a flow cytometer;

the objects being biological cells or viruses.

15. The apparatus of claim 14 in which the objects have emission cones on an input surface of the filter element, the combined transmission function having a minimum feature size approximately as large as or larger than the emission cones.

16. The apparatus of claim 13 in which the filter assembly is one of:

on an inside surface of a part bounding the channel;

on an outside surface of a part bounding the channel;

spaced by a gap from an outside surface of a part bounding the channel; and

positioned outside the channel so that an optical element outside the channel images the input light onto the filter assembly.

17. A method of using a fluidic structure that includes a channel in an application in which objects travel through the channel, the method comprising:

while each of a series of one or more objects emanates respective light within the application'"'"'s range of photon energies as it travels along a respective path through the channel, transmitting/reflecting a portion of the object'"'"'s respective light through a filter component along the channel to provide output light;

the act of transmitting/reflecting a portion of the light including;

transmitting/reflecting the portion of the light in accordance with a combined transmission function within the application'"'"'s range of photon energies, the combined transmission function being approximately equal to a superposition or scaled superposition of a set of two or more simpler transmission functions, the set including two or more simpler non-uniform transmission functions;

the filter component being positioned relative to the channel and each of a subset of at least two of the simpler non-uniform transmission functions being different from each other and positioned relative to each other in the superposition or scaled superposition so that, in response to the portion of the light, the output light has time variation in accordance with each of the functions in the subset.

18. The method of claim 17 in which the act of transmitting/reflecting further comprises:

transmitting the output light through a random multicolor filter so that the output light further has time variation in accordance with the random multicolor filter.

19. A method comprising:

producing a filter that transmits/reflects light within an application'"'"'s range of photon energies;

the act of producing the filter including;

producing the filter with a combined transmission function within the application'"'"'s range of photon energies, the combined transmission function being approximately equal to a superposition or scaled superposition of a set of two or more simpler transmission functions, the set including two or more simpler non-uniform transmission functions;

in the superposition or scaled superposition, each of a subset of at least two of the simpler non-uniform transmission functions being different from each other and positioned relative to each other so that, in response to input light within the application'"'"'s range of photon energies emanating from objects traveling along any of one or more paths past the filter, the filter provides output light with time variation in accordance with each of the functions in the subset

20. The method of claim 19, further comprising:

mathematically combining the functions in the subset.

21. The method of claim 20 in which each of the functions in the subset has a respective variation direction;

the method further comprising, before the act of mathematically combining the functions, at least one of;

positioning the functions in the subset so that their variation directions are approximately parallel; and

positioning the functions in the subset to adjust the combined transmission function'"'"'s minimum feature size.

22. The method of claim 20 in which the act of producing the filter with the combined transmission function includes:

converting the mathematically combined functions in the subset to an optical thickness function; and

using the optical thickness function in producing the filter.

23. The method of claim 22 in which the act of using the optical thickness function includes:

scaling the optical thickness function to obtain a scaled optical thickness function; and

producing the filter so that it has the scaled optical thickness function.

24. The method of claim 19 in which the filter has a range of path directions in which output light has time variation, the method further comprising:

connecting the filter into a device so that objects move past the filter along paths within the range of path directions.