EP0169496A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Image input device for processing a fingerprint prior to identification
Assignee: NEC Corp
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Filing: 1985-07-17
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Granted: —
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Expires: 2005-07-17
Abstract
Abstract In an image input device for carrying out preliminary operation prior to identification of an object placed on an input surface, the preliminary operation is for indicating a start time instant of the identification. Responsive to a succession of image signals extracted from the input surface, a timing controller produces partial image signals selected from the image signal succession in correspondence to positions which are unidimensionally or bidimensionally distributed on the input surface. Alternatively, the preliminary operaton is for detecting whether the object is true or false. In this event, grey level comparison may be made as regards selected ones of the image signals that are in correspondence to preselected positions of the input surface. Variation of the image signals may be monitored at two different time instants. A false input can be avoided by changing luminous intensities of the image signals with time or by projecting a specific pattern onto the input surface to detect the specific pattern.
Inventors
- 👤 Ko C/O Nec Corporation Asai
- 👤 Koichiro C/O Nec Corporation Morita
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 05:01
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/117; A61B5/1171; A61B5/1172; G; G06; G06V; G06V40/00; G06V40/10; G06V40/12; G07; G07C; G07C9/00; G07C9/30; G07C9/32; G07C9/37
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
69 words
An image input device for use in combination with an identification system which is for carrying out identification of an object placed on an input surface, wherein the improvement comprises: image extracting means for preliminarily extracting a preliminary image signal from said input surface prior to said identification; and detecting means responsive to said preliminary image signal for detecting whether or not said identification is to be carried out.
Claim 2
Dependent Claim
69 words
An image input device for use in combination with an identification system which is for carrying out identification of an object placed on an input surface, wherein the improvement comprises: image extracting means for preliminarily extracting a preliminary image signal from said input surface prior to said identification; and detecting means responsive to said preliminary image signal for detecting whether or not said identification is to be carried out.
Claim 3
Dependent Claim
59 words
An image input device as claimed in Claim 1, wherein said image extracting means comprises: partial image signal producing means for producing a partial image signal representative of a part of said input surface; and means coupled to said partial image signal producing means for supplying said partial image signal as said preliminary image signal to said detecting means.
Claim 4
Dependent Claim
23 words
An image input device as claimed in Claim 2, wherein said part is unidimensionally laid at a center portion of said input surface.
Claim 5
Dependent Claim
87 words
An image input device as claimed in Claim 2, wherein said partial image signal producing means comprises: image generating means for producing a succession of image signals extracted from said input surface; (Claim 4 continued) gate signal producing means for producing a gate signal during an interval of time corresponding to said center portion; and selecting means coupled to said image generating means and said gate signal producing means for selecting said image signal succession in response to said gate signal to produce said partial image signal.
Claim 6
Dependent Claim
18 words
An image input device as claimed in Claim 2, wherein said part bidimensionally distributed on said input surface.
Claim 7
Dependent Claim
19 words
An image input device as claimed in Claim 5, wherein said part is radially arranged on said input surface.
Claim 8
Dependent Claim
19 words
An image input device as claimed in Claim 5, wherein said part is regularly distributed on said input surface.
Claim 9
Dependent Claim
19 words
An image input device as claimed in Claim 5, wherein said part is irregularly distributed on said input surface.
Claim 10
Dependent Claim
34 words
An image input device as claimed in Claim 5, wherein said part is densely distributed at a center portion of said input surface and roughly distributed at a peripheral portion surrounding said center portion.
Claim 11
Dependent Claim
89 words
An image input device as claimed in any of claims 1 to 9, wherein said image extracting means comprises: image producing means for producing a succession of image signals picked up from said input surface; (Claim 10 continued) and , selecting means for selecting said image signal succession to produce selected image signals as said preliminary image signals; said detecting means comprising: comparing means responsive to said selected image signals for successively comparing said selected image signals with each other to decide whether said object is true or false.
Claim 12
Dependent Claim
66 words
An image input device -as claimed in any of claims 1 to 9, wherein said image extracting means comprises: means for producing a first succession of image signals at a first time instant and a second succession of image signals at a second time instant appearing after said first time instant; and means for producing said first and said second successions as said preliminary image signal.
Claim 13
Dependent Claim
76 words
An image input device as claimed in Claim 11, each image signal of said first and said second successions having a variable level, wherein said detecting means comprises: measuring means for successively measuring each level of said first and said second succession to produce a result of measurement; and comparing means for comparing the results of said first succession with those of said second succession to decide whether or not said object is true or false.
Claim 14
Dependent Claim
76 words
An image input device as claimed in any of claims 1 to 12, wherein said image extracting means comprises: means for projecting a predetermined pattern onto said input surface; and pickup means for picking up an optical image including said input surface and said predetermined pattern to produce said preliminary image signal; said detecting means comprising: means for detecting presence or absence of said predetermined pattern to decide whether said identification is to be carried out.
Claim 15
Dependent Claim
113 words
An image input device as claimed in any of claims 1 to 13, wherein said image extracting means comprises: illuminating means for illuminating said input surface with a first luminous intensity and a second luminous intensity different from said first luminous intensity; means for picking up a first and a second succession of image signals from said input surface when said input surface is illuminated with said first and said second luminous intensities, respectively; and means for producing said first and said second successions as said preliminary image signal; said detecting means comprising: processing means for processing said first and said second successions to decide whether said identification is to be carried out.
References Cited (Backward Citations)
No citation records indexed.
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