Optical methods for detecting the position or state of an object

• US 6,411,215 B1
• Filed: 02/10/2000
• Issued: 06/25/2002
• Est. Priority Date: 02/19/1999
• Status: Expired due to Fees

• Current Assignee: Shnier J. Mitchell
• Original Assignee: Shnier J. Mitchell
• Inventors: Shnier, J. Mitchell
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US09/501,488
• Time in Patent Office: 866 Days
• Field of Search: 340/686.1, 340/545.3, 340/568.8, 340/568.1, 340/686.6, 340/467, 340/600, 340/573.1, 340/572.1, 702/153, 250/221, 382/100, 116/201
• US Class Current: 340/686.1
• CPC Class Codes: E05B 17/22 Means for operating or controlling lock or fastening device accessories, i.e. other than the fastening members, e.g. switches, indicators E05B39/00 - E05B45/00 take precedence
• CPC Class Codes: E05B 45/06 Electric alarm locks E05B45/005 takes precedence
• CPC Class Codes: G08B 13/08 by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind

Abstract

Methods for remotely detecting whether a specific object is in a specific position or state. For example, to detect a desired condition, such as; that a residential sliding door is both fully closed and also locked, or a stove element is turned off, or that a window'"'"'s pane of glass is intact. Optical methods are used, and in one embodiment a retroreflective surface is affixed to the door'"'"'s locking handle, or the control dial for the stove element, or the glass surface, respectively, for this example. A narrow light beam illuminates the location where the retroreflective surface would be if; the door is closed and its lock handle is in the locked position, the control dial for the stove element is in the off position, or the window'"'"'s glass is intact. If a monitoring device senses the retroreflected beam of light, then the retroreflective surface must be in the desired position, and the desired condition has been confirmed. In an embodiment of another method, the monitoring device remotely detects whether an object is in a powered on or off state by using an optical assembly to receive light from the object'"'"'s power on indicator light.

Claims

1. An optical method of remotely detecting whether a first object is in a specific position, location or orientation, here called the desired position, said method comprising the steps of:

a) utilizing optically retroreflective means associated with said first object;

b) utilizing a light source which produces a beam of light, said beam of light being at least partially collimated,

c) directing said beam of light at the location where said retroreflective means would be when said first object is in said desired position;

d) utilizing means to detect the reflected light from said retroreflective means;

e) locating said means to detect said reflected light so that said means to detect said reflected light receives at least a portion of the light reflected from said retroreflective means when said first object is in said desired position;

the intensity of said light source and the collimation of said beam of light therefrom, the amount of light reflected from said retroreflective means and the divergence of said beam of light therefrom, the amount of said light reflected which is gathered by said means to detect said reflected light and the sensitivity thereof all being such that said means to detect said reflected light can be located at least one meter from said retroreflective means and said reflected light can be reliably detected,

said light source and said means to detect said reflected light both being mounted in the same sensor enclosure,

whereby, according to the light received at said means to detect said reflected light, the state or condition of an appliance, device, machine or other piece of equipment can be remotely detected, without running wiring to, or making mechanical or electrical modifications to the appliance, device, machine or other piece of equipment.

2. The method of claim 1, wherein said retroreflective means is mounted on said first object, whereby motion of said first object results in said retroreflective means moving in to and out of said beam of light, said beam of light having;

substantially the same beam width as height, and

a beam width and height which differ from the maximum diameter of said retroreflective means by no more than a factor of five,

whereby confirmation that said first object is in said desired position is obtained when said beam of light reflects from said retroreflective means back to said means to detect said reflected light, and confirmation that said first object is not in said desired position is obtained when said beam of light does not illuminate said retroreflective means, and therefore does not reflect from said retroreflective means back to said means to detect said reflected light.

3. The method of claim 2, wherein the cross-sectional shape and area of said beam of light as measured at said retroreflective means, and the shape and area of said retroreflective means, is such that the range of possible movement of said retroreflective means includes moving in to, and out of said beam of light,

whereby such range of movement produces a measurable change in the light received at said means to detect said reflected light.

4. The method of claim 1, wherein said retroreflective means is mounted such that the range of possible movement of said first object includes said first object moving in to, and out of the path of said beam of light, thereby obstructing and not obstructing said beam of light'"'"'s path to said first reflective means,

whereby said first object has a cross-sectional shape and area which can block enough of said beam of light such that a measurable change in the light received at said means for detecting said reflected light will occur according to said range of possible movement.

5. The method of claim 4, wherein said first object will not obstruct said beam of light when said first object is in said desired position, and said first object will obstruct said beam of light when said first object is not in said desired position,

whereby confirmation that said first object is in said desired position is obtained when said beam of light reflects from said retroreflective means back to said means to detect said reflected light, without being obstructed.

6. The method of claim 4, wherein said first object will obstruct said beam of light when said first object is in said desired position, and said first object will not obstruct said beam of light when said first object is not in said desired position,

whereby confirmation that said first object is not in said desired position is obtained when said beam of light reflects from said retroreflective means back to said means to detect said reflected light, without being obstructed.

7. The method of claim 1, wherein said retroreflective means is selected from the group consisting of:

a) a micro-ball based retroreflective material,

whereby a high-quality reflection with substantially uniform intensity across said reflection'"'"'s width is produced, and

b) a corner-reflector based retroreflective reflector, and

c) polarizing material, with a retroreflective backing,

whereby the angle of rotation of said polarizing material will affect the amount of light reflected, and

d) a microlouvered surface, with a retroreflective backing,

whereby the amount of light reflected will depend on the angle of incidence of said beam of light onto said microlouvered surface, and

e) overlapped Ronchi rulings, with a retroreflective backing,

whereby the amount of light reflected will depend on the angle of incidence of said beam of light onto said overlapped Ronchi rulings, and

f) other material, whereby the amount of reflected light, from said beam of light which is reflected back to said means to detect said reflected light, depends on a characteristic of how said beam impinges on said other material,

whereby said means to detect said reflected light can detect whether said first object is in said desired position, according to said reflected light.

8. The method of claim 1, wherein said first object is a movable part of another item, device or appliance, said movable part selected from the group consisting of:

a) a locking lever or knob, and

b) a control lever or dial, and

c) a handle or knob of an electrical switch, and

d) a surface of a pane of glass or door, and

e) other a physical element,

whereby said movable part'"'"'s position or presence indicates useful information concerning the state of said item, device or appliance.

9. The method of claim 1, wherein said retroreflective means is mounted directly of said first object,

whereby the presence of valuable or important objects can be continuously verified.

10. The method of claim 1, wherein said retroreflective means is mounted on a second object which moves into and out of said light path as a result of movement of said first object,

whereby the implementation of said method could be facilitated for some configurations.

11. The method of claim 1, wherein the light source is selected from the group consisting of:

a) a semiconductor laser diode, and

b) a light emitting diode,

with suitable optical elements to collimate the beam of light to a beam width in the order of a few millimeters so that said first object'"'"'s movements in the order of a few millimeters can be detected.

12. The method of claim 1, further comprising means for automatically aiming said light source, which in some sequence utilized when first installed, and while said first reflective means is in said desired position and as required thereafter, performs a recalibrating function wherein said light source is aimed at said first reflective means and stays aimed thereat until another said recalibrating function is initiated,

whereby installation and subsequent realignment is facilitated, thereby simplifying and automating the installation and any required subsequent re-aiming.

13. The method of claim 1, further comprising:

a) additional reflective means mounted at predetermined locations adjacent to said first reflective means, said predetermined locations being collinear with said first reflective means when said first reflective means is in said desired position, and said predetermined locations being non-collinear with first said retroreflective means when said first reflective means is not in said desired position;

b) means for automatically aiming said light source, which, in some sequence utilized when first installed and periodically thereafter, directs said beam of light to said additional reflective means to recalibrate the location of said desired position,

c) means for automatically aiming said light source, which will aim said light source at said desired position when not performing said recalibration;

whereby said first object can be confirmed to be in said desired position when said first reflective means and said additional reflective means are detected to be collinear, and

whereby said aiming can be self-aligning as only the relative orientation of said first reflective means to said additional reflective means is critical, rather than requiring the absolute aiming of said light source at said first reflective means.

16. The method of claims 1 or 14, wherein said light source produces light in a manner selected from the group consisting of:

a) on constantly, and

b) pulsed, with a predetermined duty cycle, and

c) analog modulated,

whereby benefits including ease of initial alignment, power savings, increased visual safety, and increased security can be realized.

17. The method of claims 1 or 14, wherein said sensor enclosure incorporates other components used to perform other functions,

whereby the sharing of said sensor enclosure provides benefits, such as disguising the implementation of said method, taking advantage of all functions needing to be performed from a similar physical location, and cost and size reduction through shared components.

18. The method of claims 1, 14 or 15, wherein a change in the light received at said means to detect said received light will result in annunciating this, utilizing a method selected from the group consisting of:

a) audible means, and

b) visual means, and

c) an electrical contact closure or equivalent electronic switching action, and

d) data communications method, and

e) radio frequency, and

f) infrared light transmission,

whereby said state or condition of said appliance, device, machine or other piece of equipment can be communicated to people or other systems.

19. The method of claim 18, wherein said annunciation is delayed for a period of time, said period of time being at least as long as an event selected from the group consisting of;

a) the time said appliance, device, machine or other piece of equipment is normally expected to be in that state, and

b) the time a person using said appliance, device, machine or other piece of equipment is normally standing at it, and

c) the time required for a person to walk past said appliance, device, machine or other piece of equipment,

whereby such expected changes in said light received will not be annunciated.

20. The method of claim 19, wherein the duration of said period of time is set by a means selected from the group consisting of:

a) at the time of manufacture, and

b) at the time of installation, and

c) by a user.

21. The method of claim 18, wherein said annunciation indicates the degree of change of said light received,

whereby the corresponding change of said first object'"'"'s state or condition can be determined.

14. An optical method of remotely detecting whether a first object is in a specific position, location or orientation, here called the desired position, said method comprising the steps of:

a) utilizing first retroreflective means mounted on said first object;

b) mounting additional retroreflective means at predetermined locations adjacent to said first reflective means, said predetermined locations being collinear with said first reflective means when said first reflective means is in said desired position, and said predetermined locations being non-collinear with first said retroreflective means when said first reflective means is not in said desired position;

c) directing a beam of light from a light source, said beam have large enough cross-section and aimed, to simultaneously illuminate said first retroreflective means as well as said additional retroreflective means;

d) utilizing optical elements, said elements including a cylindrical lens or cylindrical mirror, mounted so that the reflected light from both said first retroreflective means and said additional retroreflective means is focussed onto substantially the same first line when said first reflective means is in said desired position;

e) utilizing optical detecting means to detect whether there is a second line displaced from and parallel to said first line;

said optical detecting means need only detect line displacement along a single axis parallel to the axis of said cylindrical lens or cylindrical mirror, said light source, said optical elements, and said optical detecting means all being mounted in the same sensor enclosure, and said sensor enclosure being located at least one meter from said first object;

whereby due to said cylindrical lens or cylindrical mirror, said optical detecting means is substantially simplified due to the need to only detect the presence of a line offset along a single axis, and

whereby the requirement for accurate aiming of said beam of light is substantially reduced through the use of said cylindrical lens or cylindrical mirror, since light reflected from said first retroreflective means will be spread out to form a line, and

whereby the presence of said second line displaced from said first line indicates that said first object is not in said desired position, and

whereby the state or condition of an appliance, device, machine or other piece of equipment can be remotely detected, without running wiring to, or making mechanical or electrical modifications to the appliance, device, machine or other piece of equipment.

15. A method of remotely detecting the state of a selected first object, said selected first object requiring electricity to perform its primary function, according to light emitted by a selected indicator light, said indicator light being an integral part of the original design of said selected first object for the purpose of being directly viewed by a user thereof to directly discern said state and electrically connected to the internal electrical circuitry of said selected first object, and said selected indicator light changing a characteristic of said light emitted therefrom according to said state of said selected first object, said method comprising the steps of:

a) utilizing a detector unit which includes means to filter, focus and detect light, said filter having optical bandpass characteristics as required to attenuate the light from interfering sources while providing less attenuation of at least some of the wavelengths of said light emitted by said selected indicator light,

b) said detector unit having suitable optical elements to provide focussing and directionality so that said light emitted by said selected indicator light can be detected at a distance of at least one meter from said selected indicator light,

c) aiming said detector unit at said selected indicator light so that only said light emitted by said selected indicator light is received by said detector unit, and sources of light from possible other indicator lights and possible other sources of interfering light are not received by said detector unit;

d) detecting a characteristic of the light produced by said selected indicator light, said characteristic selected from the group consisting of;

whether said light is on or off,

the color of said light,

the intensity of said light, and

the blinking rate of said light,

whereby, according to said characteristic of the light, the state or condition of an appliance, device, machine or other piece of equipment can be remotely detected, without running wiring to, or making mechanical or electrical modifications to said appliance, device, machine or other piece of equipment.

22. The method of claim 15, wherein a partially collimated light source is located in the enclosure housing said detector unit, aimed substantially where said means to detect light is aimed, said partially collimated light source being powered off during normal mode in which said means to detect light detects light from said selected indicator light, and said partially collimated light source being powered on at some predetermined duty cycle during aiming mode to facilitate aiming said detector unit at said selected indicator light,

whereby, said aiming mode facilitates initial installation of said detector unit, and subsequent re-aiming thereof, as the location at which said means to detect light is aimed will be illuminated thereby providing an immediate visual indication of where said means to detect light is aimed, and

whereby, said normal mode enables normal operation in which said partially collimated light is powered off and will therefore not interfere with said means to detect light detecting light from said selected indicator light.

23. The method of claim 15, further comprising means for automatically aiming said detector unit, which in some sequence utilized when first installed, and while said selected indicator light is illuminated and as required thereafter, performs a recalibrating function wherein said detector unit is aimed at said selected indicator light and stays aimed thereat until another said recalibrating function is initiated,

whereby installation and subsequent realignment is facilitated, thereby simplifying and automating the installation and any required subsequent re-aiming.

24. The method of claim 15, wherein said detector unit is incorporated in a device which performs other functions,

whereby the sharing of said device'"'"'s enclosure provides benefits, such as disguising the implementation of said method, taking advantage of all functions needing to be performed from a similar physical location, and cost and size reduction through shared components.