Patent US2964952A successfully refreshed from Google Patents.
Patent EP0036739A2 successfully refreshed from Google Patents.
EP0036739A2
Expired / Lapsed
EP
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Serial dot printer for office machines
Assignee: Olivetti SpA
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Filing: 1981-03-17
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Granted: —
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Expires: 2001-03-17
Abstract
Abstract he printer comprises a solid or liquid ink jet head 100 arranged to print one dot at a time on paper running over a platen 80. The head is carried by a carriage 48 movable transversely with simple harmonic reciprocating motion. In order to reduce the effect of inertial forces when the carriage reverses its movement, the drive is effected by an eccentric peg 70 on a disc 276, the peg engaging in a guide slot 54 of the carriage perpendicular to the direction of reciprocation. An eccentric cam track 71 in the disc engages a peg 92 on a counterweight 90 for counterbalancing the inertial forces of the carriage. In order to synchronise the printing operation with the carriage movement, an optical strobe disc 256 is rigid with the disc 276 and has slots 258 disposed at a pitch varying according to the harmonic motion. The platen 80 is rotated intermit- tentlyby a helical cam 277 carried by the disc 276 and a peg wheel 280, 281. In order to compensate for discharge of a smoothing or reservoir circuit feeding the printing head 100, the duration of the pulses applied thereto can be increased in accordance with the rate at which dots are being printed. In a modification the strobe disc is replaced by a linear transducer of capacitive type, with one part carried by the carriage.
Inventors
- 👤 Michele Bovio
- 👤 Lino Sella
- 👤 Pierangelo Berruti
- 👤 Walter Gillone
- 👤 Luciano Ceresa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 14:25
CPC Classifications
B; B41; B41J; B41J19/00; B41J19/18; B41J19/20; B41J19/202; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/17; B41J2/175; B41J27/00; B41J27/16
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
89 words
A serial dot printer comprising a carriage movable transversely relative to the paper, and carrying at least one printing head which can be actuated selectively in order to print in a series of printing positions on the paper, and eccentric means for moving the carriage with harmonic motion, characterised in that the carriage (48) has a rectilinear guide (54) perpendicular to the direction of carriage movement, and the eccentric means comprise an element (70) engaged with the guide and rotatable about a shaft (22) perpendicular to the guide (54).
Claim 2
Dependent Claim
89 words
A serial dot printer comprising a carriage movable transversely relative to the paper, and carrying at least one printing head which can be actuated selectively in order to print in a series of printing positions on the paper, and eccentric means for moving the carriage with harmonic motion, characterised in that the carriage (48) has a rectilinear guide (54) perpendicular to the direction of carriage movement, and the eccentric means comprise an element (70) engaged with the guide and rotatable about a shaft (22) perpendicular to the guide (54).
Claim 3
Dependent Claim
63 words
A printer as claimed in claim 1, characterised in that the eccentric element (70) is carried by a wheel (65) and carrying a cam element (71) arranged to move a counterweight (90) parallel to the movement of the carriage but in the opposite direction, so as to counteract the inertial forces of the mass of the carriage during the reversal of its movement.
Claim 4
Dependent Claim
44 words
A printer as claimed in claim 1 or 2, in which the paper is a strip unwinding from a roll, characterised in that the printing head is of the single printing element type, and moves along the entire length of the line of print.
Claim 5
Dependent Claim
77 words
A printer as claimed in any of claims 1 to 3, in which the printing head can be selectively operated by an operating circuit to print in a series of printing positions equidistant on the paper under the control of means effecting synchronisation with the carriage movement, characterised in that the synchronisation means comprise a rotatable element (256) provided with slots (258) spaced apart by a pitch which varies according to the variable speed of the carriage.
Claim 6
Dependent Claim
24 words
A printer as claimed in claim 4, characterised in that the rotatable element comprises a disc (256) rotating rigidly with the eccentric element (70).
Claim 7
Dependent Claim
27 words
A printer as claimed in claim 4 or 5, characterised in that an optical transducer (250) cooperates with the rotatable element (256) to generate a synchronisation signal.
Claim 8
Dependent Claim
61 words
A printer as claimed in claim 6, characterised in that the optical transducer (250) comprises a light emitting diode (252) coupled optically to a phototransistor (254), an element (292) for controlling the current of the diode, and a resistor (297) connected between the phototransistor and the control element in order to vary the photodiode current in response to the synchronisation signal.
Claim 9
Dependent Claim
93 words
A printer as claimed in any of claims 1 to 3, in which the printing head is selectively operable by an operating circuit to print in a series of printing positions on the paper under the control of means effecting synchronisation with the carriage movement, characterised in that the synchronisation means comprise a capacitive transducer (122, 128), the capacitance of which varies periodically during the movement of the carriage, and generates a synchronisation signal when the capacitance assumes a predetermined value at the printing positions of the carriage (48) relative to the paper.
Claim 10
Dependent Claim
38 words
A printer as claimed in claim 8, characterised in that the capacitive transducer comprises a first plate (123) having at least one plurality of conductors (124) spaced apart by a constant pitch and connected together at one end.
Claim 11
Dependent Claim
65 words
A printer as claimed in claim 9, characterised in that the capacitive transducer comprises a second plate (128) movable relative to the first plate (123) and comprising an electrically conducting element provided with at least one plurality of slots (130) spaced apart by a distance equal to the said pitch, this element being faced by the said conductors (124), but not in electrical contact therewith.
Claim 12
Dependent Claim
25 words
A printer as claimed in claim 10, characterised in that a dielectric layer is disposed between the first plate (123) and the second plate (128).
Claim 13
Dependent Claim
38 words
A printer as claimed in claim 10 or 11, characterised in that the conductors (124) are parallel and are disposed perpendicular to the direction of movement of the carriage (48), the slots being disposed parallel to the conductors.
Claim 14
Dependent Claim
37 words
A printer as claimed in claim 12, characterised in that the conductors (124) are disposed in two parallel rows and are provided on a printed circuit (120), the slots (130) being also disposed in two parallel rows.
Claim 15
Dependent Claim
35 words
A printer as claimed in claim 11 and claim 12 or 13, characterised in that the slots (130) are in a resilient blade (128), supported by the carriage (48) and sliding on said dielectric layer.
Claim 16
Dependent Claim
55 words
A printer as claimed in any of claims 6 to 14, characterised in that the synchronisation signal (STR) is detected by a comparator (170) which compares the signal generated by the transducer (250 or 122, 128) with its mean value, the comparator supplying an output signal" (STRO) when the synchronisation signal exceeds the mean value.
Claim 17
Dependent Claim
37 words
A printer as claimed in claim 15, characterised in that the signal (STRO) from the comparator (170) authorises a signal (ABAT) emitted by a buffer memory (151) for controlling the operating circuit (Fig 6 or Fig 12).
Claim 18
Dependent Claim
67 words
A printer as claimed in claim 16, in which the printing head comprises at least one printing element of the ink jet type, and the operating circuit is arranged to cause a particle of ink to be transported on the paper, characterised in that the operating circuit comprises a voltage transformer (200) supplied by a switch (198) controlled by the signal (ABAT) from the buffer memory (151).
Claim 19
Dependent Claim
28 words
A printer as claimed in claim 17, characterised in that the operating circuit is supplied by a voltage source by way of a smoothing filter (190 or 402).
Claim 20
Dependent Claim
32 words
Printer as claimed in claim 18, characterised in that the operating circuit comprises a timer circuit (415) for varying the duration of the pulses generated by the switch (198) and transformer (200).
Claim 21
Dependent Claim
79 words
Printer as claimed in claim 19, in which the head is of the solid ink jet type and in which the operating circuit is selectively operable to apply pulses to the solid ink which are negative relative to a counter-electrode, characterised in that the timer circuit (415) is controlled in such a manner as to vary the duration of the pulses in accordance with a voltage which depends on the number of consecutive pulses applied to the ink (102).
Claim 22
Dependent Claim
22 words
Printer as claimed in claim 20, characterised in that the timer circuit comprises a monostable multivibrator (415) controlled by said dependent voltage.
Claim 23
Dependent Claim
105 words
Printer as claimed in any of claims 19 to 21, comprising a power supply unit for the generating circuit arranged to supply a constant voltage at an output terminal and having a first inductance, characterised in that the first inductance (Ll) is connected to an oscillator transistor (T 1 ) a second inductance L 2 ) is coupled to the first inductance and connected to said oscillator transistor in order to establish a feedback voltage and is connected in series with a second transistor (T 2 ) in order to modify the feedback voltage in response to the voltage variations at the output terminal (VM).
Claim 24
Dependent Claim
35 words
Printer as claimed in claim 22, characterised in that a Zener diode is connected between said output terminal and the base of said second transistor in order to establish a threshold for said voltage variations.
Claim 25
Dependent Claim
46 words
A printer as claimed in any of the preceding claims, characterised in that the paper is fed intermittently by a linkage (286, 285, 284, 283, 280, or 84, 86, 88, 35) driven by a cam (277, 278 or 25, 28) rigid with the eccentric element (70).
Claim 26
Dependent Claim
32 words
A printer as claimed in claim 24, characterised in that the linkage comprises a wheel (280) with frontal pegs (281) engaging the cam, and which is rotatable about a horizontal axis (282).
References Cited (Backward Citations)
No citation records indexed.
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