WO2001092033A1

WO2001092033A1 - Access card having a code extracted by reflected light

Info

Publication number: WO2001092033A1
Application number: PCT/AU2001/000600
Authority: WO
Inventors: Frederick Clerk
Original assignee: Embridge Lake Pty Ltd
Current assignee: Embridge Lake Pty Ltd
Priority date: 2000-05-26
Filing date: 2001-05-23
Publication date: 2001-12-06
Anticipated expiration: 2002-11-26
Also published as: AUPQ777200A0

Abstract

There is described a control apparatus for controlling operation of a device, the control apparatus including a light source (3), a control card (5) having a code thereon, said control card capable of emitting light in response to incident light from said light source in such a manner that said code is capable of being extracted from the emitted light, light capture means (19) for capturing said emitted light, code extraction means (23, 33) for extracting said code from said captured light, code validation means (37) for determining whether the extracted code is valid and operation means (41) for operating a device when said code is determined to be valid by said code validation means.

Description

CONTROL APPARATUS

Field of the Invention

The present invention relates to a control apparatus for controlling operation of devices. More speci ically, the invention relates to controlling the operation of doors and hence the access of persons, goods, vehicles or other objects to buildings or particular areas of buildings. The invention finds particular application in controlling the access of persons to buildings or particular areas of buildings, however, it should be understood that the invention is not limited to this particular application. For example, the control apparatus of the invention may be used to control the operation of a particular piece of machinery by controlling whether the machine operates or the manner in which it operates .

Background of the Invention

There are several current techniques for controlling the access of persons to buildings. Most of these systems are based on persons carrying a personal access card which will permit them to access a building and particular areas within that building. Most current systems require the person using the access card to present their access card to some form of reader in order to pass through locked doors, or to access floors of the building via a lift. Typically, the user swipes their card through a swipe card reader, the card is read by the reader and a code contained thereon analysed to determine whether the code permits access to the particular area of the building. If so, the locking mechanism on the door to the area is deactivated and the user may proceed through the door. Alternatively, the door may open automatically. A similar type of card is a non-contact card which must be brought into close proximity with a reader which uses an electromagnetic field in order to determine whether a correct access code is contained on the card. In this manner entry is restricted to authorised personnel only.

Both of the foregoing systems have a distinct disadvantage in that the user must physically present their card to a reader each time they come to a locked door. It can be difficult for a user to present their card if they have their hands full with other articles such as brief cases, lap top computers or packages . In an attempt to overcome this problem, access systems have been proposed which incorporate transponders. Transponders may be passive or active radio-frequency devices which, in response to a radio-frequency signal, radiate a signal incorporating information regarding the identity of the responder such as a code. A transponder may use the energy of the incoming radio to impress the identity information on the return signal, and therefore, is a passive device which does not generally consume energy. Systems which incorporate transponders require an antenna located at each door to broadcast a signal at a particular radio frequency. The antenna also monitors the frequency on which signals return from transponders and when it encounters a transponder signal containing a valid code, deactivates the locking mechanism for that door. A major problem with transponder systems is that it is difficult to establish a precise read zone. That is, it is difficult to single out a particular transponder from a group. For example, a person may be attempting to gain access to an area to which they do not have right of access and hence the transponder monitor will be monitoring the area but not locating any valid codes. If then, a person who does have the right to access this area moves within the range of the transponder monitor, the lock will be deactivated and the person who does not have a right to access the area, will be permitted entry. Another disadvantage of transponder based access systems is that radio frequency readers emit high frequency signals which can interfere with other equipment in sensitive areas and in some locations it may not be possible to set up the reader because of presence of other interfering radio frequency sources. Furthermore, the cost of access cards for transponder based systems is relatively high.

The object of the present invention is to provide an alternative control apparatus for controlling the operation of device .

Summary of the Invention

Accordingly, the invention provides a control system for controlling operation of a device, the control system including:

a light source;

a control card having a code thereon, said control card capable of emitting light in response to incident light from said light source in such a manner that said code is capable of being extracted from the emitted light?

light capture means for capturing said emitted light;

code extraction means for extracting said code from said captured light;

code validation means for determining whether the extracted code is valid; and

operation means for operating a device when said code is determined to be valid by said code validation means. Thus, as a person or object having a control card approaches a device which is to be operated (e.g. a door lock) light impinges on the card causing light to be emitted (e.g. by reflection) which is then captured, and processed to extract the code which if valid causes the device to operate (e.g. opens the door lock).

Preferably said light source radiates light which is not visible. In a preferred embodiment, said light source is an infrared light source.

Herein "emitting light" includes "reflecting light"

Preferably said code is inscribed on said control card in a material which will only reflect light at the frequency of the incident light source, said reflected light being the light emitted by said control card in this case.

Alternatively, said code may be inscribed in a material which will be excited by incident light at a first frequency to emit light at a second frequency.

Preferably, the code is inscribed as a code pattern and only the area of the control card containing the code pattern emit light. Alternatively, all areas of the control card other than the code pattern may emit light whereby the code pattern may be inferred from the absence of light.

In one embodiment, the control card may incorporate additional electronic components including a transmitter, whereby the control card may transmit additional information when light from said light source is incident on said access card and said system contains means for receiving and processing said information.

In a preferred embodiment, the control card is an access card which controls access to an area by controlling the operation of a door.

Brief description of the drawings

An embodiment of the invention will now be described with reference to the accompanying drawings in which:

Figure 1 is an exploded view of an access card for use in the control apparatus of an example of the preferred embodiment;

Figure 2 is an exploded view of an alternative access card;

Figure 3 is a detail view of Figure 2;

Figure 4 is a schematic diagram showing the various elements of a control apparatus according to the present invention; and

Figure 5 is a schematic diagram showing the key features of the so tware element of the control apparatus .

Description of the preferred embodiment

In the example, the control apparatus is an access system for controlling access to a building or an area of the building which employs control cards in the form of access cards having a code thereon which must be validated before the locking mechanism of a door will be operated to permit access to the building or an area of the building.

As illustrated in figure 3 the access system 1 according to an example of the embodiment of the invention incorporates a light source in the form of an infrared light source 3 and access card 5 having a code in the form of a code pattern 7 thereon. In response to incident light 9 from the infrared light source 3 the access card emits light in such a manner that the code can be extracted by the other components of the access system.

In the access card 5 illustrated in figure 1 the first layer 13 is made of a material that is transparent at infrared light frequencies but opaque to visible light. The second layer 15 is made of a material which absorbs infrared light but contains a code pattern 7 in the form of. plurality of punched holes which allows the incident light 9 to pass through the second layer 15 and strike a third reflective, layer 17 which reflects the light passing through the holes so that the emitted light 11 (i.e. the reflected light) only comes from the coded pattern 7 whereby the code can be extracted from the emitted light 11. Alternatively, the second and third layers may be combined, and constitute reflective material (defining the code) embedded in or attached to a non reflecting background, or vice versa. Light capture means in the form of an infrared sensitive camera 19. The camera 19 may be fitted with a lens or a combination of lenses which facilitate the formation of a suitable image of the code pattern 7 and may also include means for shuttering the image capture such that non-blurred images can be formed and captured even when the access card is in motion by sampling images at short exposure intervals .

Returning to figure 3, the infrared light source 3 and the camera 19 are connected to other elements of the access system via a hardware interface 21. An image extractor 23 is provided in order to extract images from the output 20 of the infrared camera 19 for further processing. These images will contain an image of the code on the access card. The extracted images are stored in image memory 25 for processing. Software tools 29 carry out processing of the image data under control of processor 27 in order to extract the code from the image and to determine whether the code is valid. As shown in figure 4 the software 29 incorporates a number of elements including software for controlling the acquisition of images 31, software for image enhancement 33 and software for image analysis and pattern recognition 35. The image acquisition software controls both the camera 19 and the image extractor 23 in order to obtain images for further processing from the emitted light. The image enhancement software 33 enhances these images so that they are suitable for further processing. The image analysis and pattern recognition software 33 extracts the code from the enhanced image so that it can be presented to validity determining means 37 in appropriate format - for example, as characters and numbers or other recognisable information. The validity determining means 37 then checks the code against a code database 39 to determine whether the code is valid. The code database 39 can be stored locally or alternatively may be stored remotely in which case communication means are provided in order to allow the validity determining means 37 to contact the code database 39. Depending on the result of the determination process carried out by the validity determining means 37, appropriate control signals are generated by output controller 41 and passed via hardware interface 21 to outputs 43a, 43b and 43σ. These outputs may be used to preform a variety of functions such as providing a visual and/or audible sign as to whether the door will be opened or not and controlling the opening of a door.

In the preferred embodiment the infrared light source 3 emits light having a wavelength in the range of 750 to 950 nanometers. The light source may be an array of light emitting diodes, or may be a xenon tube having peaks near 800mm and 900mm used in conjunction with a filter in order to reduce the visible light components. The lamp may be pulsed, to increase illumination, while maintaining a low consumed lamp power.

Multiple lamps each emitting different wavelengths can be used. For example, two lamps could be used if the reflective material has different reflective properties at the two different wavelengths. The resulting images can then be compared in order to improve the resolution of the code pattern with respect to other parts of the image.

The system may incorporate conventional motion systems in order to control operation of the infrared light source 3 so that it only operates when persons are actually approaching the door. Furthermore, the image acquisition control 31 may include means for controlling the camera 19 to focus on only a particular area so that access cards 5 outside of this area will not be processed.

The infrared sensitive camera can consist of a charged coupled or similar array sensor which is sensitive to the wavelength of the energy to be detected from the access card 5.

The reflective material is preferably constructed with retro-reflective or cat"s-eye properties so that it will reflect light at a number of angles. In this way incident light reflected by the reflective material would be able to be picked up by the camera 19 even if the card is at an angle. In an alternative embodiment more than one light source 3 and or more than one camera 19 may be used in order to pick up the image.

The preferred embodiment has a number of advantageous over the existing systems. Access cards may be fabricated from passive materials and therefore not require any integrated electronic components and therefore can be manufactured at a lower cost. The access system allows cards to be read at a distance of up to several meters and therefore, eliminates the difficulty of having to bring the card into contact with the reader. The use of infrared light allows the access card 5 to be illuminated and read without the illumination being visible to the user. The code inscribed on the access card 5 will not be visible in ordinary light and therefore is more secure than systems incorporating traditional bar codes as the access cards 5 can not be readily copied. Furthermore infrared illumination and reading of the access cards 5 does not require radio frequency spectrum- allocation and will not cause radio frequency inter erence. The infrared illumination may be focused more readily on a particular area so as to eliminate access being granted to a person who does not have a valid code when there is a person with a valid code in the area. Furthermore, infrared radiation does not penetrate the access card 5 and its user and therefore any access card located behind the user will not respond and cause interference. Furthermore, if there are responses from multiple cards, the code extraction means can determine from the image, for example, by the size of the image, which card is the front card and therefore, which card it should respond to.

There are various alternatives which may be incorporated into the foregoing system. One alternative is to provide an access card 5 as shown in figure 2 which incorporates a light shutter 47 which operates under light shutter controller 49. Such a system allows the code pattern presented on the access card 5 to be varied by selectively altering the areas of the access card 5 through which light is reflected. The light shutter 47 is composed of a number of individual elements 48 each of which are controllable by light shutter controller 49 so that the code pattern 7 can be varied. The light shutter controller 49 may incorporate a memory of a number of different codes and vary the codes on a cyclical basis. Alternatively, the controller 49 may include means of connecting it to apparatus for reprogramming the code pattern.

In a further preferred embodiment which is not illustrated, the code pattern 7 may be inscribed in the material which will be excited to fluorescence by incident illumination at a first frequency to thereby emit light at a second frequency.

In an alternative embodiment the control system may be used to determine whether an operator is permitted to operate a device such as a piece of machinery and to only allow the machine to operate in the presence of an operator wearing a control card having a valid code thereon. Alternatively, the machine may operate in different manners in dependence on the code contained on the control card which may be attached to an item to be processed by the machine. For example, in a car plant, the colour of paint sprayed onto a car may depend on the code contained on a control card.

In further alternative embodiments, the control system may be used to identify items such as packages, pallets, vehicles, containers, components, fixed assets, animals or other objects, or to automatically enable the issuing or dispensing of goods from secure enclosures or compounds or too provide privileged access or services in venues, entertainment complexes, or the like. The size of the control card used may be varied to suit the particular application. For example, a load of pallets on a truck could be individually fitted with a card on each pallet. A control system reader could be mounted to capture the image of all control cards at once, and then the individual control card identifiers could be determined by the control system software. The read range of the system may be extended by using large format control cards. Also, the card may be encoded with standardised code patterns such as the two dimensions dot code, or a standard bar code.

These and other modifications may be made without departing from the ambit of the invention, the nature of which is to be determined from the forgoing description. Furthermore, the software to carry out various functions of the invention can be written by competent software writers once the required functionality is understood.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A control apparatus for controlling operation of a device, the control apparatus including: a light source; a control card having a code thereon, said control card capable of emitting light in response to incident light from said light source in such a manner that said code is capable of being extracted from the emitted light; light capture means for capturing said emitted light; code extraction means for extracting said code from said captured light; code validation means for determining whether the extracted code is valid; and operation means for operating a device when said code is determined to be valid by said code validation means .

2. Apparatus as claimed in claim 1, wherein said light source emits light which is not visible.

3 Apparatus as claimed in claim 2, wherein said light source is an infrared light source.

4. Apparatus as claimed in claim 1, wherein said code is inscribed on said control card using a material which will only reflect light at the frequency of the incident light source.

5. Apparatus as claimed in claim 1, wherein said code is inscribed in a material which will be excited by incident light at a first frequency to emit light at a second frequency.

6. Apparatus as claimed in claim 4 or claim 4, wherein the code is inscribed as a code pattern and only the area of the control card containing the code pattern will emit light.

7. Apparatus as claimed in claim 4 or claim 5, wherein all areas of the control card other than the code pattern may emit light whereby the code pattern may be inferred from the absence of light.

8. Apparatus as claimed in claims 1 to 7, wherein the control card incorporates a transmitter, whereby the control card transmits additional information when light from said light source is incident on said access card and said system contains means for receiving and processing said information.

9. Apparatus as claimed in claims 1 to 8, wherein the control card is an access card which controls access to an area by controlling the operation of a door.

10. A method for controlling operation of a device, the control system including: providing a control card having a code thereon, said code being valid for operation of said device, said control card capable of emitting light in response to light directed onto said card in such a manner that said code is capable of being extracted from the emitted light; directing light onto said control card; capturing said emitted light; extracting said code from said captured light; determining whether the extracted code is valid; and operating said device when said code is determined to be valid by said code validation means.