US4184781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Defect detector
Assignee: Oki Electric Industry Co Ltd
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Filing: 1978-04-10
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Granted: 1980-01-22
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Expires: 1998-04-10
Abstract
Abstract The present invention discloses a dot printer in which means are provided for detecting deterioration of dot print elements which print characters and so on and for detecting trouble caused by a print drive circuit. Print sensing elements are placed at a suitable point of a platen corresponding to a traverse range of dot print elements which are housed within a printing head and a mechanism for driving each dot print element is provided when said dot print elements move in front of the above-said print sensing elements sensing signal is generated when said dot print elements effect printing on the print sensing elements, to indicate the existence of trouble of the print drive circuit or dot print elements.
Inventors
- 👤 Toshimichi Ota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:31
CPC Classifications
B; B41; B41J; B41J7/00; B41J7/96; B41J29/00; B41J29/38; B41J29/393
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
125 words
In a dot printer employing a movable print head including movable print elements to effect printing paper, a printing platen located opposite said print head with said printing paper being located between said print head and printing platen, said print head movable across said platen from a home position to a right boundary position, an improvement comprising a dot printer defect detector comprising means for moving said movable print elements to their print positions; means to sense the impact of said movable print elements moving to their print positions; means to detect if any of said movable print elements fail to move to said print position; and indicating means to indicate when any of said movable print elements fail to move to said print position.
Claim 2
Dependent Claim
125 words
In a dot printer employing a movable print head including movable print elements to effect printing paper, a printing platen located opposite said print head with said printing paper being located between said print head and printing platen, said print head movable across said platen from a home position to a right boundary position, an improvement comprising a dot printer defect detector comprising means for moving said movable print elements to their print positions; means to sense the impact of said movable print elements moving to their print positions; means to detect if any of said movable print elements fail to move to said print position; and indicating means to indicate when any of said movable print elements fail to move to said print position.
Claim 3
Dependent Claim
14 words
The invention as claimed in claim 1, wherein said indicating means comprises alarm means.
Claim 4
Dependent Claim
32 words
The invention as claimed in claim 1, wherein said indicating means comprises light means, said light means further indicating which of said movable print elements fails to move to its print position.
Claim 5
Dependent Claim
25 words
The invention as claimed in claim 1, wherein said indicating means operates prior to a line being printed on said papers by said print head.
Claim 6
Dependent Claim
55 words
The invention as claimed in claim 1, wherein said means to sense comprises print sensing elements located on said platen to be struck by said print elements, and said means to detect comprises a drive mechanism for driving said dot print elements when said dot print elements move in front of said print sensing elements.
Claim 7
Dependent Claim
29 words
The invention as claimed in claim 5, wherein the number and arrangement of said print sensing elements are related to the number and arrangement of said dot print elements.
Claim 8
Dependent Claim
37 words
The invention as claimed in claim 5, wherein said drive mechanism comprises means to generate a print head position signal and said dot print elements are simultaneously moved by the generation of said print head position signal.
Claim 9
Dependent Claim
63 words
The invention as claimed in claim 5, wherein said means to detect further comprises a print head position detector and a light source located opposite therefrom, said print head being carried on a carriage, and light blocking means connected to said carriage to block the light from impinging on said print head position detector from said light source to actuate said drive mechanism.
Claim 10
Dependent Claim
26 words
The invention as claimed in claim 5, wherein said print sense elements are located on said platen corresponding to the home position of said print head.
Claim 11
Dependent Claim
15 words
The invention as claimed in claim 5, wherein said print sense elements comprise piezo-electric elements.
Claim 12
Dependent Claim
59 words
The invention as claimed in claim 5, wherein said drive mechanism comprises means to generate a print head position signal which causes said dot print elements to impact said print sense elements, said print sense elements generating respective signals upon being impacted, and sampling means for sampling the print sense elements to determine if said respective signals are generated.
Claim 13
Dependent Claim
74 words
The invention as claimed in claim 11, wherein said sampling means comprises a plurality of two-input AND gates, one input of each of said AND gates being connected to receive a respective one of said respective signals, and delay means connected between said print head position signal and the second inputs of said AND gates so that said second inputs receive said delayed signal during the time that said respective signals are being generated.
Claim 14
Dependent Claim
48 words
The invention as claimed in claim 12, further comprising counter means, wherein each of said dot print elements is successively driven, said counter means receiving said printing head position signal and a timing signal and generating successive counts to enable said dot print elements to be successively driven.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-21 | 1983-07-23 | 1984-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-21 | 1987-07-23 | 1988-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-21 | 1991-07-23 | 1992-01-22 | $7700.00 | Window Closed / Lapsed |