Curved Refractive Lens for Keypad Security
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Solution Overview
Problem
The increasing incidence of fraudulent activities involving the unauthorized use of cash cards at ATMs and retail PIN entry devices, where criminals obtain PINs by observing users or using cameras to view the keypad, highlights the need for enhanced security measures to protect PIN entry processes.
Innovation Solution
A keypad security device featuring an enclosure with a viewing aperture and an access aperture, incorporating a refractive lens security pane that allows authorized users to view the keypad clearly while preventing observation from unauthorized individuals, including those standing nearby or using remote cameras, with the lens being inclined or curved to reduce glare and improve user access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a flat transparent pane is used in the viewing aperture, then the keypad is easily viewed by anyone, but security against unauthorized viewing is poor
Solution Approach 1:
The patent applies a curved security pane instead of a flat transparent pane. The curvature is specifically designed to distort the view of the keypad when viewed from angles other than the intended user perspective. This allows the keypad to remain visible to the authorized user while preventing unauthorized viewing from side angles or remote positions, thus resolving the contradiction between ease of viewing and security.
Solution Approach 2:
The patent changes the optical parameters of the viewing aperture by introducing a refractive lens with specific curvature radius (100mm to 500mm). This parameter change transforms the viewing characteristics so that the keypad is only clearly visible through the intended viewing aperture, while appearing distorted or obscured from other angles, thereby achieving both ease of operation for authorized users and security against unauthorized viewing.
2Reliability
If a curved security pane is used, then unauthorized viewing is prevented and glare is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent specifies a curved security pane with a defined radius of curvature range (100mm to 500mm). This curvature is designed to prevent unauthorized viewing and reduce glare while remaining manufacturable using standard optical lens fabrication techniques. The specified range provides flexibility in manufacturing while achieving the desired security function.
Solution Approach 2:
The patent establishes specific parameter ranges for the refractive lens including curvature radius (100mm to 500mm) and refractive index (1.3 to 1.8). These parameter specifications guide the manufacturing process and ensure that the security pane can be produced using conventional methods while achieving the required optical properties for security and glare reduction.
3Reliability
If a refractive lens with high curvature is used, then unauthorized viewing is more effectively prevented, but hand access for user becomes more difficult
Solution Approach 1:
The patent specifies a curvature radius range (100mm to 500mm) that balances security and usability. This moderate curvature is sufficient to distort the keypad view for unauthorized observers while maintaining adequate hand access for the authorized user. The range allows optimization based on specific application requirements.
Solution Approach 2:
The patent establishes a refractive index range (1.3 to 1.8) and curvature radius range (100mm to 500mm) that together optimize the balance between security and ease of operation. These parameter changes ensure that the lens provides sufficient distortion for security while maintaining transparency and accessibility for the user's hand and fingers.
4Reliability
If the security pane is made opaque to prevent viewing, then security is improved, but the user cannot view the keypad at all
Solution Approach 1:
The patent uses a curved transparent pane with refractive properties rather than an opaque pane. The curvature and refraction work together to selectively allow viewing from the intended angle while blocking viewing from other angles. This resolves the contradiction by maintaining transparency for authorized viewing while providing security through optical distortion.
Solution Approach 2:
The patent changes the optical parameters (refractive index between 1.3 and 1.8, curvature radius between 100mm and 500mm) to create a pane that is transparent to authorized users but distorted to unauthorized observers. This parameter optimization allows the pane to function as both transparent and secure simultaneously, resolving the contradiction between visibility and security.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The security device effectively shields keypad entries from unauthorized viewing, ensuring that only the user can observe the keypad, thereby reducing the risk of PIN theft and enhancing the security of cash card transactions at ATMs and retail POS systems.
Implementation Method 1
the security pane includes a refractive lens... the security pane includes a refractive lens, and the security pane is inclined relative to the keypad
Implementation Method 2
By curving the security pane, problems associated with glare from, for example light sources around or above the device are reduced
Data Source
AI summary
A keypad security device (100) comprises an enclosure having a viewing aperture (114) and an access aperture (152). The enclosure at least partially surrounds a keypad such that the keypad is viewable through the viewing aperture (114) and accessible by a user through the access aperture (152). The viewing aperture includes a security pane (116) arranged so as to permit the keypad to be viewed clearly from the point of view of a user of the keypad and to prevent the keypad from being viewed from the point of view of a person other than the user, wherein the security pane (116) is curved and comprises a flexible refractive lens.