Circuit for indicating the condition of the battery in a _photographic camera

US4211478A · kind A · utility

Assignee

• AGFA-Gervaert AG · DE

Inventors

• Theodor Huber · Munich, DE
• Kurt Borowski · Aschheim, DE
• Gerhard Egger · Munich, DE

Key dates

• Filing date: Apr 19, 1978
• Grant date: Jul 8, 1980
• Expiry date: Apr 19, 1998

Classification

• Technology area (CPC G): Physics
• CPC primary: G03B17/18
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

When the battery voltage is sufficient, and not nearing the point of insufficiency, a light-emitting diode is steadily illuminated. As the battery voltage decreases, the steady component of illumination decreases and also, when the decrease has proceeded to a certain extent, a superimposed pulsating component of illumination is introduced, causing the illuminated LED to begin to flicker, informing the user that the battery voltage is nearing insufficient values. As battery voltage drops further, the steady component of illumination ceases altogether, and the flicker converts to on-off blinking, indicating that the battery voltage is at the verge of an insufficient value. When the battery voltage drops further, the LED ceases to be illuminated. During part or all of the flicker phase, and/or during part or all of the blinking phase, the frequency of the pulsating component of illumination progressively increases with decreasing battery voltage, to create an effect of increasing urgency. In addition, or alternatively, at a certain point during pulsating illumination the frequency of the pulsating component is abruptly increased, likewise to create an effect of urgency.