Optical lock systems and methods

• US 8,196,823 B2
• Filed: 08/10/2010
• Issued: 06/12/2012
• Est. Priority Date: 08/10/2010
• Status: Active Grant

• Current Assignee: Toyota Motor Corporation
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Grayson, Benjamin Alan, Benerjee, Debasish, Zhang, Minjuan, Uehara, Yasuo, Ishii, Masahiko
• Primary Examiner(s): Sharifzada, Ali
• Application Number:
  US12/853,718
• Publication Number:
  US 20120036905A1
• Time in Patent Office: 672 Days
• Field of Search: 235/375, 235/384, 235/435
• US Class Current: 235/384
• CPC Class Codes: G02B 27/0012 Optical design, e.g. procedures, algorithms, optimisation routines
• CPC Class Codes: G02B 5/0825 the reflecting layers comprising dielectric materials only
• CPC Class Codes: Y10T 70/5889 For automotive vehicles
• CPC Class Codes: Y10T 70/7051 Using a powered device [e.g., motor]

Abstract

In one embodiment, the optical lock system may include an electronic control unit, a lock housing including a lock chamber, and an optical key including a multilayer photonic structure. The multilayer photonic structure may produce a unique intensity profile and includes a plurality of coating layers of high index dielectric material and a plurality of coating layers of low index dielectric. A light source may transmit a reference light to the multilayer photonic structure when the optical key is disposed within the lock chamber. A photo detector may receive an interaction light from the multilayer photonic structure and may transmit the unique intensity profile to the electronic control unit which may execute machine readable instructions to: compare the unique intensity profile to an electronic master; and cause the lock actuator to transition from a first state to a second state when the unique intensity profile corresponds to the electronic master.

Claims

1. An optical lock system comprising:

an electronic control unit comprising a processor for executing machine readable instructions and an electronic memory;

a lock housing comprising a lock chamber;

an optical key comprising a multilayer photonic structure and a mounting aperture, wherein the multilayer photonic structure produces a unique intensity profile and comprises a plurality of coating layers of high index dielectric material having an index of refraction n_H and a plurality of coating layers of low index dielectric material having an index of refraction n_L, and a transparent substrate, wherein a first coating layer is coupled the transparent substrate and the transparent substrate is mounted within the mounting aperture;

a light source optically coupled to the lock chamber and communicatively coupled to the electronic control unit, wherein the light source transmits a reference light to the multilayer photonic structure when the optical key is disposed within the lock chamber;

a photo detector optically coupled to the lock chamber and communicatively coupled to the electronic control unit, wherein the photo detector receives an interaction light from the multilayer photonic structure when the optical key is disposed within the lock chamber and transmits the unique intensity profile of the multilayer photonic structure to the electronic control unit; and

a lock actuator communicatively coupled to the electronic control unit, wherein the electronic control unit executes the machine readable instructions to;

compare the unique intensity profile to an electronic master; and

cause the lock actuator to transition from a first state to a second state when the unique intensity profile corresponds to the electronic master.

2. The optical lock system of claim 1 wherein the index of refraction n_L is from about 1.4 to about 1.6.

3. The optical lock system of claim 1 wherein the index of refraction n_H is from about 1.9 to about 2.3.

4. The optical lock system of claim 1 wherein:

the plurality of coating layers of high index material consists of 5 to 20 coating layers of high index material; and

the plurality of coating layers of low index material consists of 4 to 19 coating layers of low index material.

5. The optical lock system of claim 1 wherein the light source opposes the first coating layer of the multilayer photonic structure and the photo detector opposes the transparent substrate of the multilayer photonic structure.

6. The optical lock system of claim 1 wherein the light source emits broadband light.

7. An optical lock system comprising:

a multilayer photonic structure comprising a plurality of coating layers of high index dielectric material having an index of refraction n_H and a plurality of coating layers of low index dielectric material having an index of refraction n_L;

a light path comprising a reference light and an interaction light, wherein a light source transmits the reference light to the multilayer photonic structure, the reference light interacts with the multilayer photonic structure to produce the interaction light, and the interaction light is received by a photo detector;

an electronic control unit comprising a processor for executing machine readable instructions and an electronic memory, wherein the electronic control unit is communicatively coupled to the light source and the photo detector, such that the electronic control unit executes the machine readable instructions to;

receive an intensity profile indicative of the interaction light from the photo detector;

quantize a magnitude of the intensity profile at a wavelength; and

compare a quantized magnitude to an electronic master stored in the electronic memory.

8. The optical lock system of claim 7 wherein the light source opposes a first coating layer of the multilayer photonic structure and the photo detector opposes the first coating layer of the multilayer photonic structure.

9. The optical lock system of claim 7 wherein:

the multilayer photonic structure further comprises an opaque substrate, wherein a first coating layer is coupled to the opaque substrate; and

the optical lock system further comprises an optical key comprising a mounting surface, wherein the opaque substrate is mounted on the mounting surface.

10. The optical lock system of claim 7 wherein the index of refraction n_L is from about 1.4 to about 1.6 and the index of refraction n_H is from about 1.9 to about 2.3.

11. The optical lock system of claim 7 wherein the plurality of coating layers of high index dielectric material and the plurality of coating layers of low index dielectric material are alternately arranged and a first coating layer and a last coating layer of the multilayer photonic structure comprise high index dielectric material.

12. The optical lock system of claim 7 wherein the light path passes through the multilayer photonic structure and the intensity profile is a transmittance profile.

13. The optical lock system of claim 7 wherein the light path is reflected by the multilayer photonic structure and the intensity profile is a reflectance profile.

14. The optical lock system of claim 13 wherein a reflection angle is formed between the reference light and the interaction light and the reflection angle is about zero.

15. The optical lock system of claim 7 wherein the electronic control unit executes the machine readable instructions to quantize one or more additional magnitudes of the intensity profile at one or more additional wavelengths.

16. A method for operating an optical lock comprising:

transmitting a reference light to a multilayer photonic structure tuned to produce a unique intensity profile, wherein the unique intensity profile is a reflectance profile, a transmittance profile, or a combination thereof;

detecting the unique intensity profile;

quantizing a magnitude of the unique intensity profile at a wavelength;

comparing the unique intensity profile to an electronic master; and

activating a lock actuator to transition the optical lock from a first state to a second state when the unique intensity profile corresponds to the electronic master.

17. The method of claim 16 further comprising:

transmitting one or more additional reference lights to the multilayer photonic structure, wherein the multilayer photonic structure is tuned to produce one or more additional intensity profiles; and

detecting the one or more additional intensity profiles.

18. The method of claim 16 wherein the optical lock is utilized in a vehicle.