Seiko Epson Corporation

Naoto Yamaguchi

Masayuki Kumazaki

Yukihiro Uchiyama

Hiroshi Ishida

Kazuhiko Yamaguchi

Takumi Sato

A continuous paper cutting unit including a press mechanism for pressing and holding both sides of the perforations of continuous paper by a press means link mechanism, and a cutting mechanism like a blunt instrument using a cutting means link mechanism. With the appropriate placement of the paper guides, the transport of the continuous paper is smooth and the cutting of the continuous paper along the perforations thereof is preformed reliably using a small drive force.

Continuous paper cutting unit

A sheet end detector comprising a light-emitting element and a light-receiving element for detecting changes in the amount of light associated with movement of a piece of a recording medium is provided. A standard value calculator detects the difference between the sheet end detector platen voltage Vp corresponding to light reflected only from said platen and said sheet end detector paper saturation voltage Vm corresponding to light reflected only from the recording medium. The amount necessary to feed the paper for platen voltage Vp to reach paper saturation voltage Vm is a constant value, irrespective of recording medium characteristics, which is when all of the light is reflected by the recording medium and the entire end portion of a piece of a recording medium has reached a predetermined position relative to the position of the sheet end detector. A standard value is calculated by multiplying this difference by a constant coefficient C and then adding back the lesser of Vp or Vm, C being a numerical value greater than 0 and less than 1 and being an indication of the desired position of the leading edge of the recording medium. A comparator compares the standard value and a signal from the sheet end detector and determines when the signal corresponds to the standard value, which is indicative that the presence of a leading edge or trailing edge of the recording medium has reached a predetermined position.

Method for detecting an end portion of a recording medium in a recording

A paper detection device for a printer, includes: a support member; a main lever pivotably mounted on the support member, wherein the main lever has a self-resetability to an upright position and is pivotable only in a sheet-feed-direction; an auxiliary lever pivotably mounted on the main lever, including a free end protruding into a sheet passage, wherein the auxiliary lever has a self-resetability and moves the main lever in the sheet-feed direction when the free end thereof is urged in the sheet-feed direction, but does not move the main lever in a reverse-sheet-feed direction when the free end of the auxiliary lever is urged in a reverse-sheet-feed direction.

Paper detection device for printer

A ribbon mask for use with a impact dot matrix printer is provided. The ribbon mask comprises a head confronting surface and a pair of opposed side plates each positioned on an opposite side of the head confronting surface. An obtuse angle is formed between said head confronting surface each of the opposed side plates. A pair of fitting tabs are also provided. Each fitting tab is positioned on one of the pair of opposed side plates. An acute angle is formed between each of the fitting tabs and a plane parallel to a plane in which the head confronting surface lies. As a result of this construction, when the ribbon mask comes in contact with a sheet of a recording medium, the ribbon mask is deformed so that a portion of the head confronting surface comes into contact with an end of a recording head, which in turn prevents the ribbon mask from interfering with the sheet of the recording medium.

Ribbon mask for impact dot matrix printed

An automatic adjusting device for accurately adjusting a platen gap including an encoder 14 for outputting pulse signals in accordance with a moving distance of a carriage, a pulse width detector for detecting a pulse width of the pulse signal when the carriage is moved from a reference position in a direction of the platen, a difference calculator for calculating a difference between a pulse width of the pulse signal sent from the pulse width detector and a pulse width of a stored pulse signal, a contact detector for judging a contact position of the recording head with the platen surface by comparing the difference with the reference value, and a controller for controlling a platen gap in accordance with the thickness of a recording medium charged on the platen detected by a pulse signal sent from the encoder and a signal sent from the contact detector. A change in the pulse width caused by resistance on the carriage is subtracted by the difference detector to obtain correction data so that the contact point can be accurately detected.

Automatic adjusting device for adjusting platen gap

A method of printing on a printing medium is provided, including providing a printing head for printing on a recording medium and conveying the recording medium in a first direction with a conveyer. A detector is positioned on the upstream side of the print head, the detector then detecting a trailing edge of the recording medium. The amount of recording medium conveyance by the conveyer upon the detection of said trailing edge is computed and it is determined whether the recording medium is of a standard size. Thereafter, a printing region on the recording medium is defined in accordance with the size of the recording medium if the recording medium is a standard size. A printer for printing on a printing medium which employs the above method is also provided wherein a detector is positioned upstream of the print head for detecting a trailing edge of the recording medium which is being conveyed. A computer computes the amount of the recording medium conveyance by the conveyer upon the detection of the trailing edge by the detector, and a size determiner determines whether the recording medium is of a standard size and defines a printing region on the recording medium in accordance with the size of the recording medium if the recording medium is of a standard size.

Paper size determining method and printer in which the method is used

A printing method of playing out piled sheets of paper one by one, feeding the played-out sheet of paper to the position of a platen, and printing the sheet of paper, the printing method includes the steps of: (a) feeding the sheet of paper played out from the piled position thereof at a first speed until the sheet of paper approaches a platen which is stopping; (b) feeding the sheet of paper at a second speed lower than the first speed until a required short time passes from a time when the sheet of paper is engaged with the stopping platen, for performing a sheet flexing and a sheet skew removing; and (c) driving the platen at the second speed to feed the sheet of paper to a printing position. And the printing apparatus performs the printing method.

Printing method and printing apparatus

A follower roller 100 adapted to be rotated while coming in contact with a recording medium 120 is rotatably mounted on a driving roller shaft 114 of a driving roller 113, i.e., one of an opposing pair of driving rollers 111 and 113, and a rotation detector 115 for detecting the rotation of the follower roller 100 is disposed in the vicinity of the driving roller 113. A controller detects a malfunction of paper clogging by comparing the detection signal outputted from the rotation detector 115 with the driving signal outputted from the controller for rotationally driving a paper feeding motor. The follower roller 100 includes a ring-shaped magnet 121 including a plurality of magnet segments which are alternately magnetized in such a manner that adjacent magnet segments exhibit different magnetic poles with a radially extending boundary line as a boundary therebetween.

Printing apparatus

A tractor and a continuous paper feed mechanism using the same which can more accurately convey continuous paper in a forward or reverse paper conveying direction by compensating for an increase or decrease in the width (taper) of the continuous paper due to a change in temperature or humidity. The change in paper width is compensated for by either employing a tractor having a pin belt that can incline relative to the paper conveying direction or by employing a tractor that pivots in accordance with the change in paper width to incline the pin belt.

Tractor mechanism compensating for paper taper

An apparatus for conveying paper in a printer adapted to convey cut-sheet and fan-fold paper bidirectionally in a paper path. The apparatus includes a paper discharging assembly positioned downstream of a print head and at least one paper conveying assembly positioned upstream of the print head. First and second power transmissions cooperate with the paper conveying and the paper discharging assemblies, respectively, to convey the paper in both a forward and reverse direction to desired printing positions and to convey the paper away from the print head. The paper conveying assembly grips the paper with greater force than the paper discharging assembly while the second power transmission has greater play b2 than the play b1 of the first power transmission. In order to convey the paper in the reverse direction the motor rotates a distance equal to b1+an amount of rotation MAXd2 equal to the distance in the second direction to a desired second printing position from the first printing position absent any play)+(an additional amount of rotation .gamma.). The motor then rotates in the forward position an amount equal to (b1+.gamma.) to drive the paper to the second desired printing position.

Growing community of inventors

Nagano, Japan

Naoto Yamaguchi