EP0049462A2
Expired / Lapsed
EP
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Memory device
Assignee: Olympus Corp
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Filing: 1981-09-29
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Granted: —
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Expires: 2001-09-29
Abstract
Abstract A memory device, which comprises a capacitor (20) connected to a power supply terminal (10) through a main switch (12) to be used as a data holding power source and also connected to a read write memory (24). The memory device further comprises a comparator (22) which compares the level of the terminal voltage of the capacitor (20) with a minimum level of the data holding voltage of the memory (24) and a transistor (16) which is connected between the main switch (12) and capacitor (20) and rendered conducting in accordance with an output signal from the comparator (22).
Inventors
- 👤 Kowji Tanikawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 10:52
CPC Classifications
G; G11; G11C; G11C14/00; G06; G06F; G06F1/00; G06F1/26; G06F1/28; G11C5/00; G11C5/14; G11C5/141
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
83 words
A memory device which comprises: volatile read write memory means (24); power supply means (10) which is connected to said read write memory means (24) to always supply voltage to said read write memory means (24); and characterized by further comprising judgment means (14) which compares the level of a voltage supplied by said power supply means (10) and a prescribed voltage level, and, when the power supply voltage has a lower level than the prescribed voltage level, sends forth a detection signal.
Claim 2
Dependent Claim
83 words
A memory device which comprises: volatile read write memory means (24); power supply means (10) which is connected to said read write memory means (24) to always supply voltage to said read write memory means (24); and characterized by further comprising judgment means (14) which compares the level of a voltage supplied by said power supply means (10) and a prescribed voltage level, and, when the power supply voltage has a lower level than the prescribed voltage level, sends forth a detection signal.
Claim 3
Dependent Claim
24 words
The memory device according to claim 1, which further comprises an alarm display section (38) energized by the detection signal from said judgment means.
Claim 4
Dependent Claim
60 words
The memory device according to claim 1 or 2, wherein, upon receipt of a detection signal, data stored in said memory means (24) is converted into a prescribed data; and the prescribed voltage of the judgment means (22, 54) is chosen to have a higher level than a minimum level of a data holding voltage of said memory means (24).
Claim 5
Dependent Claim
119 words
The memory device according to claim 3, wherein said judgment means (14) comprises, a main switch (12), one end of which is connected to the power supply terminal (10), a switching member (16) which is connected between the other end of the main switch (12) and the power supply terminal of said memory means (24), is normally left open and, upon receipt of the detection signal, is closed, a capacitor (20) connected between the junction of the switching member (16) and memory means (24) on one hand and the ground on the other, and a comparator (22) which compares the level of the terminal voltage of the capacitor (20) and the prescribed voltage level and issues the detection signal.
Claim 6
Dependent Claim
105 words
The memory device according to claim 3, wherein said judgment means (14) comprises a main switch (12), one end of which is connected to the power supply terminal (10), a current to voltage conversion element (52) which is connected between the other end of the main switch (12) and the power supply terminal of the memory means (24), a capacitor (56) connected between junction of the conversion element (52) and memory means (24) on one hand and the ground on the other, and a comparator (54) sending forth the detection signal in accordance with the level of the terminal voltage of the conversion element (52).
References Cited (Backward Citations)
No citation records indexed.
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