Abstract In order to improve security for holographic labels which are positioned on a substrate base, a bar code symbol with regions of different light reflective properties is holographically recorded on the base. The base may be, for example an information card, such as a credit card, a label, or a container for a product. The bar code symbol can be recorded so that it is visible to the eye in white light (e.g., as a rainbow hologram) or so that it requires an appropriate reference beam for reconstruction. A reading apparatus (e.g., a bar code reader) directs light at the holographic bar code symbol and detects the reflected optical information with a detector such as a CCD array. The reading apparatus can be a stand-alone device or, in the case of a credit card, can be incorporated into a conventional swiper for reading magnetic information on a strip on the card. A non-holographic bar code symbol can also be provided on or near a holographic display element, e.g., a rainbow hologram. The bar code can be positioned adjacent the display, or placed in a window within the display, or etched or embossed on the display. A system is also provided for authenticating a holographic display on an information card such as a credit card. A display is illuminated and a reflected beam directed at a holographic record which was previously produced from a signal, known to be authentic, and a reference. The reflected beam is used to reconstruct a reference beam. A sensor receives the reconstructed reference and it is then determined if the display is authentic.
A bar code reader for reading a bar code symbol holographically recorded in a holographic element on a substrate base, said apparatus comprising: a structure including a channel sized and configured to receive said substrate base; an illumination source mounted with respect to said structure and positioned to direct light at said holographic element; a detector mounted with respect to said structure and positioned to receive a holographic reconstruction of said symbol; said detector including an optical sensor for receiving optical information from said reconstruction and converting said optical information into electrical signals; said illumination source and said optical scanner being so positioned and configured that said optical sensor receives said holographic reconstruction as said substrate is moved along said channel.
Claim 2
Dependent Claim
121 words
A bar code reader for reading a bar code symbol holographically recorded in a holographic element on a substrate base, said apparatus comprising: a structure including a channel sized and configured to receive said substrate base; an illumination source mounted with respect to said structure and positioned to direct light at said holographic element; a detector mounted with respect to said structure and positioned to receive a holographic reconstruction of said symbol; said detector including an optical sensor for receiving optical information from said reconstruction and converting said optical information into electrical signals; said illumination source and said optical scanner being so positioned and configured that said optical sensor receives said holographic reconstruction as said substrate is moved along said channel.
Claim 3
Dependent Claim
36 words
The apparatus of claim 1 wherein said detector is positioned to receive a virtual image of said symbol, and said apparatus further includes at least one optical element for directing said virtual image to said detector.
Claim 4
Dependent Claim
13 words
The apparatus of claim 2 wherein said optical element comprises a relay lens.
Claim 5
Dependent Claim
18 words
The apparatus of claim 1 wherein said detector is positioned to receive a real image of said symbol.
Claim 6
Dependent Claim
15 words
The apparatus of claim 2 or 4 wherein said optical sensor comprises a CCD array.