Seiko Epson Corporation

Seiko Espon Corporation

Kazuhiko Yamaguchi

Masayuki Kumazaki

Yukihiro Uchiyama

Naoto Yamaguchi

Hiroshi Ishida

Sanshiro Takeshita

Kazuhiro Hashii

Tatsuya Seshimo

Tomoyuki Mokuo

Susumu Murayama

Kazuhisa Nakamura

Seiichi Hirano

Hiroyuki Sugimoto

Kouichirou Yokoyama

It is provided with a pair of carriage guide shafts, and the carriage guide shaft is made to be in sliding contact with a carriage, to realize such a concentric shaft configuration that a guide shaft part, which directly guides a reciprocating motion of the carriage, and rotation shaft parts, which are disposed on both ends thereof, were disposed so as to coincide therewith. In addition, by disposing parallel lifting device which utilized a cam mechanism and a lifting guide portion to side frames, the carriage guide shaft is configured so as to be able to obtain a predetermined lifting stroke which corresponds to a rotation angle. In addition, as synchronous drive transmission mechanism of the pair of carriage guide shafts, a gear wheel train was used.

Gap adjusting device, recording apparatus and liquid ejection apparatus

In a platen gap adjustment device, a stable area detection device for a platen gap formed between ahead and an upper surface of a platen, wherein the carriage guide shaft is moved relatively to the platen so that the platen gap is adjusted by driving the drive motor to rotate the gap adjuster cam, the gap adjuster cam is configured so as to provide a plurality of stable areas and a plurality transition areas; and wherein a stable area detection sensor is provided so as to face to a rotational member which rotates synchronously with the gap adjuster cam, and a detection object in correspondence with the stable areas of the platen gap is provided on the rotational member.

Stable area detection device of platen gap and recording apparatus

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 sheet end detecting mechanism incudes: an optical-type sheet detector which is sensitive to a reflected light from a recording sheet surface is disposed at a slightly upper-path-side part of the printing position in a sheet conveyance direction; and an auxiliary mechanical-type sheet end detector which is displaced by passing of a recording sheet is disposed on the upper path side of the sheet detecting means.

Sheet end detecting mechanism

A sheet feed/discharge roller mechanism that includes a plurality of driving rollers and a driven roller shaft disposed in the roller mechanism that is freely displaceable to the driving rollers. A plurality of driven rollers are mounted on the driven roller shaft in facing relationship with the driving rollers. A plurality of roller supporting members apply forces to the driven roller shaft for biasing the driven rollers towards the driving rollers. The forces applied to at least one of the driven rollers is greater than the forces applied to at least a second driven roller.

Sheet feed/discharge roller mechanism

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

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 printer including at least two tractor unit mounting sections upstream of the print position in the sheet feed direction, and at least one tractor unit can be mounted on either of these tractor unit mounting sections. The sheet feeding direction can thus be selected freely in accordance with the web replacement frequency or the printer installation location merely by changing the mounting position of the tractor unit. If the number of tractor units is increased, a plurality of webs can be set up simultaneously and used selectively.

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Nagano, Japan

Kazuhiko Yamaguchi