WO2009110893A1

WO2009110893A1 - Lock assemblies and methods involving photo-voltaic devices

Info

Publication number: WO2009110893A1
Application number: PCT/US2008/055885
Authority: WO
Inventors: Rakesh Radhakrishnan
Original assignee: Utc Fire And Security Corporation
Priority date: 2008-03-05
Filing date: 2008-03-05
Publication date: 2009-09-11

Abstract

Lock assemblies and methods involving photo-voltaic devices are provided. In this regard, a representative method for powering an electronic lock comprises using light from an interior of a structure to power an electronic lock located within the structure.

Description

LOCK ASSEMBLIES AND METHODS INVOLVING PHOTO-VOLTAIC

DEVICES

BACKGROUND Technical Field

The disclosure generally relates to locks.

Description of the Related Art

Electronic door locks have become commonplace, particularly in the hotel industry. Such locks incorporate a locking mechanism that responds to an actuation command provided by a controller for opening the lock. Typically, the actuation command is provided from the controller in recognition of a coded entry device, such as a key card with an encoded magnetic strip.

SUMMARY

Lock assemblies and methods involving photo-voltaic devices are provided. In this regard, an exemplary embodiment of a lock assembly for a door comprises: a housing mounting a locking mechanism, a photo-voltaic device, a rechargeable battery and a controller; the locking mechanism being movable between a locked position and an unlocked position; the photo-voltaic device being operative to charge the rechargeable battery; the rechargeable battery being operative to power the controller; the controller being operative to issue commands for enabling the locking mechanism to be moved between the locked position and the unlocked position. Another exemplary embodiment of a lock assembly for a door comprises: a housing defining an interior; a locking mechanism mounted by the housing, the locking mechanism being operative to selectively secure a position of the door; a photo-voltaic device mounted by the housing; and a controller; the photo-voltaic device being operative to provide electrical power for the controller; the controller being operative to issue commands for controlling operation of the locking mechanism.

An exemplary embodiment of a device for powering an electronic lock comprises using light from an interior of a structure to power an electronic lock located within the structure.

Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a schematic diagram depicting an exemplary embodiment of a lock assembly involving a photo-voltaic device. FIG. 2 is a schematic diagram depicting another exemplary embodiment of a lock assembly involving a photo-voltaic device.

FIG. 3 is a schematic diagram depicting another exemplary embodiment of a lock assembly involving a photo-voltaic device.

FIG. 4 is a flowchart depicting an exemplary embodiment of a method for powering an electronic lock.

DETAILED DESCRIPTION

Lock assemblies and methods involving photo-voltaic devices are provided, several exemplary embodiments of which will be described in detail. In this regard, some embodiments are configured as electronic door locks that use light from both sides of a door to power electronic components of the lock assembly. In some of these embodiments, the light is provided along at least two optical paths to a photo-voltaic power device located within a housing of the lock assembly.

Referring now to the schematic diagram of FIG. 1 , an exemplary embodiment of a lock assembly involving a photo-voltaic device is depicted. As shown in FIG. 1 , lock assembly 100 is mounted to a door 102 that has at least one surface located within a structure 104. By way of example, the door can be a room door of a hotel, with one side of the door facing an interior corridor and the other side facing the interior of a guest room.

A housing 106 of the assembly mounts a locking mechanism 108, a photo-voltaic device 110 and a controller 112. The locking mechanism 108 is movable between a locked position, in which a portion of the mechanism forms an interference fit with a corresponding component of a door frame for securing a position of the door, and an unlocked position. The photo-voltaic device 110 is mounted to a surface of the housing that is typically positioned adjacent to one of the sides of the door. The photo-voltaic device converts light energy into electrical energy for powering controller 112. The controller issues commands (e.g., electrical signals) for enabling the locking mechanism to be moved between the locked position and the unlocked position.

In the embodiment of FIG. 1 , photo-voltaic device 110 includes an active surface 118, which is defined as a surface that is positioned for receiving light. Optical concentrator 120 is located on the active surface. The optical concentrator increases an intensity of the light incident upon the active surface (such as by focusing multiple lower intensity light waves into a single higher intensity wave) and, therefore, improves the efficiency of the photo-voltaic device. Notably, indoor light may typically exhibit a power density of 1 W/m². Given an arbitrary upper practical limit of approximately 10X for concentration, approximately 10 W/m² of light can be provided to a photo-voltaic device along an optical path when using a concentrator. At 40% efficiency, this results in approximately 4 W/m² or 0.4 mW/cm². This means that a 5 cm x 5 cm active surface of a photo-voltaic device can generate approximately 10 mW. Greater power densities can potentially be achieved by using multiple optical paths and/or using higher density light sources.

In some embodiments, the optical concentrator and/or the photo-voltaic device can incorporate an optical filter (e.g., a film coating filter) for permitting passage of photon energies that are matched to the band gap of the photo-voltaic device. In this regard, the optical filter can remove specific wavelengths such as by reflection and/or absorption. In some embodiments, the wavelengths enabled to propagate beyond the optical filter are matched to the band gap of the photo-voltaic device, and thus the propagated light is able to excite electrons of the photo-voltaic device so that the electrons can be conducted. By way of example, solar radiation extends from approximately 0.5 eV to approximately 4.0 eV, and Si exhibits a band gap of approximately 1.1 eV. Clearly, different materials exhibit different band gaps, therefore, optical filters can be selected, based at least in part, on the light source and the band gap of the photo-voltaic device. Notably, in some embodiments, optical filters could be used on all the optical paths providing light to a photo-voltaic device.

Another exemplary embodiment of a lock assembly involving a photo-voltaic device is depicted in FIG. 2. As shown in FIG. 2, lock assembly 130 is mounted to a door 132. A housing 134 of the assembly mounts a locking mechanism 136, a rechargeable battery 138, a photo-voltaic device 140 and a controller 142. The locking mechanism 136 is controllable between a locked position and an unlocked position. The photo-voltaic device 140 is mounted within the housing and positioned so that at least two separate optical paths are provided for propagating light to the photo-voltaic device. In this case, optical paths 141 and 143 are provided, with each of the paths originating on a different side of the housing. Notably, an optical concentrator 144 is positioned along optical path 141 and an optical concentrator 146 is positioned along optical path 143 in order to increase the intensity of light propagating along those paths. An optical filter 145 also is located along path 141. In some embodiments, the components positioned along the optical paths (e.g., the optical concentrators and/or the photo-voltaic device) can be movable to accommodate optimal positioning in order to increase energy harvesting of the assembly.

Photo-voltaic device 140 coverts light energy received from one or both of the optical paths into electrical energy, which is provided to re-chargeable battery 138. The re-chargeable battery (which can be a lithium-ion battery, nickel metal hydride battery or a lead acid battery, for example) powers controller 142, which controls the locking mechanism. It should be noted that light provided along optical path 141 is filtered by optical filter 145 so that one or more selected wavelengths of light are propagated to the photo-voltaic device.

Another exemplary embodiment of a lock assembly involving a photo-voltaic device is depicted in FIG. 3. As shown in FIG. 3, lock assembly 150 is mounted to a door 152. A housing 154 of the assembly mounts a locking mechanism 156, a rechargeable battery 158, photo-voltaic devices 160, 162, a controller 164 and a card reader 166. A key card 168 also is provided.

The locking mechanism 156 is controllable between a locked position and an unlocked position. Photo-voltaic device 160 is mounted to receive light from a first side of the door, and photo-voltaic device 162 is mounted to receive light form the other side of the door. In this embodiment, each of the photo-voltaic devices is mounted to an exterior surface of the housing. An optical concentrator 161 is positioned to increase the intensity of light provided to device 160, and an optical concentrator 163 is positioned to increase the intensity of light provided to device 162. In operation, the photo-voltaic devices can independently convert light energy into electrical energy and provide that energy to re-chargeable battery 158. The rechargeable battery powers controller 164, which controls the locking mechanism. In this regard, the card reader 166 provides input to the controller responsive to detecting designated information contained by key card 168. In some embodiments, the information can be encoded on a magnetic strip, RFID tag or computer chip, for example.

FIG. 4 is a flowchart depicting an exemplary embodiment of a method for powering an electronic lock. In this regard, the method involves the functionality depicted in block 200, in which light from an interior of a structure is used to power an electronic lock located within the structure. In some embodiments, the electronic lock is a door lock mounted to an interior door of the structure, with the light from the interior of the structure being provided to a photo-voltaic device associated with the electronic lock.

In some embodiments, the light is provided from both sides of the door for powering the lock. Notably, this can include a photo-voltaic device receiving light from multiple optical paths or each of multiple photo-voltaic devices receiving light from corresponding optical sources, for example.

In some embodiments, light is directed to a photo-voltaic device, which converts the light energy to electrical energy for charging rechargeable battery. The battery is then used to power the electronic lock with electricity. In some embodiments, electricity can be selectively applied directly from the photo-voltaic device to an electronic component (e.g., a controller) without being provided first to a battery. Various functionality, such as that described above with respect to a controller, can be implemented in hardware and/or software. In this regard, a computing device can be used to implement various functionality, such as that associated with the controller 112 of FIG. 1 , for example.

In terms of hardware architecture, such a computing device can include a processor, memory, and one or more input and/or output (I/O) device interface(s) that are communicatively coupled via a local interface. The local interface can include, for example but not limited to, one or more buses and/or other wired or wireless connections. The local interface may have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers to enable communications.

It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims.

Claims

1. A lock assembly for a door comprising: a housing mounting a locking mechanism, a photo-voltaic device, a rechargeable battery and a controller; the locking mechanism being movable between a locked position and an unlocked position; the photo-voltaic device being operative to charge the re-chargeable battery; the rechargeable battery being operative to power the controller; the controller being operative to issue commands for enabling the locking mechanism to be moved between the locked position and the unlocked position.

2. The lock assembly of claim 1 , wherein: the housing defines an interior; and the photo-voltaic device is mounted within the interior.

3. The lock assembly of claim 2, wherein: the housing has a first surface, operative to be mounted adjacent to a first side of the door, and a second surface, operative to be mounted adjacent to a second side of the door, the first side opposing the second side; and the photo-voltaic device is operative to receive light through a first aperture located in the first surface of the housing.

4. The lock assembly of claim 3, wherein the photo-voltaic device is further operative to receive light through a second aperture located in the second surface of the housing.

5. The lock assembly of claim 3, further comprising an optical concentrator positioned along an optical path to the photo-voltaic device, the optical concentrator being operative to increase an intensity of light incident upon the photo-voltaic device.

6. The lock assembly of claim 5, wherein the optical concentrator is integrally formed with an active surface of the photo-voltaic device.

7. The lock assembly of claim 5, wherein the optical concentrator is mounted to the first surface of the housing.

8. The lock assembly of claim 3, wherein: the photo-voltaic device is further operative to receive light through a second aperture located in the second surface of the housing; and the lock assembly further comprises a first optical concentrator positioned along a first optical path to the photo-voltaic device, and a second optical concentrator positioned along a second optical path to the photo-voltaic device.

9. The lock assembly of claim 1 , wherein: the housing has a first surface operative to be mounted adjacent to a first side of the door and a second surface operative to be mounted adjacent to a second side of the door, the first side opposing the second side; and an active surface of the photo-voltaic device is mounted adjacent to the first surface of the housing.

10. The lock assembly of claim 9, wherein: the photo-voltaic device is a first photo-voltaic device; and the lock assembly further comprises a second photo-voltaic device, with an active surface of the second photo-voltaic device being mounted adjacent to the second surface of the housing.

11. A lock assembly for a door comprising: a housing defining an interior; a locking mechanism mounted by the housing, the locking mechanism being operative to selectively secure a position of the door; a photo-voltaic device mounted by the housing; and a controller; the photo-voltaic device being operative to provide electrical power for the controller; the controller being operative to issue commands for controlling operation of the locking mechanism.

12. The lock assembly of claim 11 , further comprising a rechargeable battery operative to power the controller, the rechargeable battery being further operative to be recharged by the photo-voltaic device.

13. The lock assembly of claim 11 , wherein: the housing has a first surface, operative to be mounted adjacent to a first side of the door, and a second surface, operative to be mounted adjacent to a second side of the door, the first side opposing the second side; and the photo-voltaic device is operative to receive light through a first aperture located in the first surface of the housing and through a second aperture located in the second surface of the housing.

14. The lock assembly of claim 13, further comprising: a first optical concentrator positioned along a first optical path to the photo-voltaic device; and a first optical filter positioned along the first optical path.

15. The lock assembly of claim 13, further comprising: a card reader mounted by the housing and operative to provide an input to the controller responsive to detecting a key card containing designated information; and a key card containing information to be read by the card reader.

16. The lock assembly of claim 15, wherein the key card has a magnetic strip containing the information.

17. A method for powering an electronic lock comprising: using light from an interior of a structure to power an electronic lock located within the structure.

18. The method of claim 17, wherein: the electronic lock is a door lock mounted to an interior door of the structure; the light from the interior of the structure is provided to a photo-voltaic device associated with the electronic lock.

19. The method of claim 18, wherein the light is provided from both sides of the door to the photo-voltaic device.

20. The method of claim 17, wherein, in using the light, the light is directed to a photo-voltaic device for charging rechargeable battery and the battery powers the electronic lock with electricity.