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US3825927A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic discboard

Assignee: Individual
•
Filing: 1972-06-14
•
Granted: 1974-07-23
•
Expires: 1992-06-14
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Abstract

Abstract A magnetic display device of the type wherein magnetized discs are selectively moveable within closely spaced openings or chambers in a laminated panel, the panel including a pair of magnetized sheets with their magnetic poles similarly disposed, openings extending through both sheets, and a bipolar magnetized disc positioned within each opening for rotation and shuttle movement under the influence of a selectively applied magnetic field, and non-magnetic cover sheets secured to opposite surfaces of the magnetic sheets. A light panel is mounted on the rear surface of the laminated panel. Shuttling of the discs with a magnetic stylus from the rear, a position of rest (erase state) to the front (write state) exposes a ray of light in each chamber. The display of individual characters is achieved by the forward and rear movement of the individual discs in each chamber. When the discs are in the rear (erase state), they block the rays of light coming through the rear panel. This is easily accomplished since the diameter of the chambers in the rear is smaller than the diameter of the front chambers. However, when the discs are in the (write state) forward position, the ray of light from each chamber is free to travel to the front panel. This then presets (in the dark) a pattern of characters in the form of small dots of light.

Inventors

  • 👤 R Passien

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 22:59
CPC Classifications
G; G09; G09F; G09F9/00; G09F9/30; G09F9/37; G09F9/375; G02; G02B; G02B26/00; G02B26/02; G02B26/026

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 111 words
A magnetic display device including a pair of magnetized sheets positioned parallel to each other with their magnetic poles similarly disposed, a series of spaced openings extending through each of said sheets, a bipolar magnetic disc positioned within each opening for rotation about a lateral axis of the opening and movement along the longitudinal axis of the opening, and a nonmagnetic cover sheet secured to each magnetized sheet, the cover sheet secured to one magnetized sheet being transparentn while the cover sheet secured to the other magnetized sheet is rigid and is provided with a series of holes smaller in diameter than said discs, the holes being aligned with the openings.
Claim 2
Dependent Claim 111 words
A magnetic display device including a pair of magnetized sheets positioned parallel to each other with their magnetic poles similarly disposed, a series of spaced openings extending through each of said sheets, a bipolar magnetic disc positioned within each opening for rotation about a lateral axis of the opening and movement along the longitudinal axis of the opening, and a nonmagnetic cover sheet secured to each magnetized sheet, the cover sheet secured to one magnetized sheet being transparentn while the cover sheet secured to the other magnetized sheet is rigid and is provided with a series of holes smaller in diameter than said discs, the holes being aligned with the openings.
Claim 3
Dependent Claim 43 words
The display device of claim 1, where a panel of electric light with a simple switch is laiminated to the back oF the display, thereby making it possible to use it in the dark as a pattern of alphanumeric characters written in lights.
Claim 4
Dependent Claim 36 words
Magnetic display device of claim 1, wherein the rigid cover sheet is made of steel making the device more durable and stable and, hence, acceptable for use in public schools as a replacement for the chalkboard.

References Cited (Backward Citations)

US2853830A Cited
US3036300A Cited
US3140553A Cited
US3103751A Cited
US3162849A Cited
US3186115A Cited
US3036388A Cited
US3210757A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-07-22 1978-01-21 1978-07-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-07-22 1982-01-21 1982-07-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-07-22 1986-01-21 1986-07-23 $7700.00 Window Closed / Lapsed

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