JP3703619B2

JP3703619B2 - Printer paper feed mechanism

Info

Publication number: JP3703619B2
Application number: JP04490298A
Authority: JP
Inventors: 省二松田
Original assignee: Alps Electric Co Ltd
Current assignee: Alps Alpine Co Ltd
Priority date: 1998-02-26
Filing date: 1998-02-26
Publication date: 2005-10-05
Anticipated expiration: 2018-02-26
Also published as: JPH11240644A

Description

【０００１】
【発明の属する技術分野】
本発明は、記録紙を紙送りローラに手差し給紙するときに発生する紙送りローラのバックラッシュを、容易に取ることができるプリンタの紙送り機構に関する。
【０００２】
【従来の技術】
従来のプリンタの紙送り機構は、図６に示すように、紙送りローラ１１と、この紙送りローラ１１の歯車部１１ｂに噛み合う中間歯車１２と、この中間歯車１２の歯車部１２ａに噛み合う歯車部１３ｂを有するモータ等から成る駆動源１３と、前記紙送りローラ１１に圧接し、紙送りローラ１１の回転に従動して回転する従動ローラ１４とから構成されている。
このような構成の従来のプリンタの紙送り機構の動作は、記録部材８を手差しで矢印Ｒ方向に送る。そして、駆動源１３を矢印Ｂ方向に回転させて、中間歯車１２を介して矢印Ｄ方向に回転状態の紙送りローラ１１で記録部材８を下流側に若干搬送する。
【０００３】
前記駆動源１３、中間歯車１２、紙送りローラ１１の、歯車部１１ａ、１２ａ１３ｂが互いに噛み合った状態の、歯先部分には図示しない微小な隙間が発生し、この微小な隙間により紙送りローラ１１にバックラッシュが発生する。
このようなバックラッシュのあるプリンタの紙送り機構を用いて印刷すると、バックラッシュの寸法だけ、紙送りローラ１１の回転がバラツキ、記録部材８の送りズレが発生したりして、記録部材に印刷した画像の印刷品質が悪くなる問題があった。
前述のような歯車のバックラッシュをなくするには、歯山の形状、および寸法にバラツキのない、高精度な歯車が要求される。しかし、このような高精度な歯車は非常に高価なので、低価格が要求される小型のプリンタ等においては、使用するのが難しい状況であった。
【０００４】
そこで、バックラッシュがあっても、印刷品質を悪くしない従来のプリンタの紙送り機構の動作は、手差しで記録部材８を紙送りローラ１１側に送り、駆動源１３を矢印Ｂ方向に回転させて、中間歯車１２を介して、紙送りローラ１１を矢印Ｄ方向に回転させ、前記手差し状態のままの記録部材８を、下流側に若干搬送して、駆動源１３の回転を一旦停止させる。
その後、駆動源１３の回転を矢印Ｅ方向に反転させ、中間歯車１２を介して、紙送りローラ３を矢印Ｇ方向に回転させて、記録部材８を紙送りローラ１１から外れない程度まで、矢印Ｌ方向の上流側に若干戻す。
【０００５】
次に、駆動源１３を再度矢印Ｂ方向に回転させ、中間歯車１２を介して紙送りローラ１１を矢印Ｄ方向に所定量回転させて、記録部材８の頭出しを行う。
この記録部材８の頭出し後、記録部材８に所望の画像を印刷し、紙送りローラ１１を矢印Ｄ方向に回転させて、印刷後の記録部材８を紙送りローラ１１の下流側に排出する。
前述のように、従来のプリンタの紙送り機構は、手差しと、矢印Ｄ方向の回転状態の紙送りローラ１１とで記録部材８を若干紙送りローラ１１の下流側に搬送後、紙送りローラ１１を矢印Ｇ方向に一旦逆転させて、記録部材８を矢印Ｌ方向の上流側に戻す。
その後再度紙送りローラ１１を矢印Ｄ方向に回転させて、記録部材８を下流側に搬送して、印刷後の画像にバックラッシュの影響がでないようにしていた。
【０００６】
【発明が解決しようとする課題】
しかし、前述のような従来の紙送り機構は、紙送りローラ１１に記録部材８が送られてくると、記録部材８を下流側に送る動作と、上流側に戻す動作とで紙送りローラ１１のバックラッシュを取るようにしていたので、操作者が記録部材８の搬送を開始してから印刷が終了するまでの時間（スループット）が長くなる問題があった。
本発明は紙送りローラ１１のバックラッシュの影響をなくして、常に安定した高品質の印刷画像を得ると共に、前記スループットを向上させ、印刷時間を短縮することができるプリンタの紙送り機構を提供するものである
【０００７】
【課題を解決するための手段】
前記課題を解決するための第１の手段として本発明のプリンタの紙送り機構は、回転可能な紙送りローラと、この紙送りローラに圧接すると共に前記紙送りローラの回転に従動して回転する従動ローラと、前記紙送りローラと前記従動ローラとに狭持されて搬送される記録部材と、この記録部材に所望の画像を印刷する記録ヘッドと、前記紙送りローラを回転駆動させる駆動源とを備え、
前記従動ローラを前記紙送りローラの圧接させた状態で前記紙送りローラを回転させて前記記録部材を手差し給紙と前記紙送りローラの回転とで下流側に若干搬送した後前記紙送りローラの回転を一時停止させる第１の紙送り動作と、この第１の紙送り動作後、前記紙送りローラの回転で前記記録部材を更に下流側に送り、前記記録部材の印刷開始部を前記記録ヘッドまで送る第２の紙送り動作とで、前記記録部材の頭出しを行うようにした構成とした。
【０００８】
また、前記課題を解決するための第２の手段として本発明のプリンタの紙送り機構は、前記紙送ローラと前記駆動源とに歯車部を形成し、この紙送ローラと前記駆動源との間に中間歯車を配設し、前記駆動源の回転を前記中間歯車を介して前記紙送りローラに伝達するようにした構成とした。
【０００９】
また、前記課題を解決するための第３の手段として本発明のプリンタの紙送り機構は、前記紙送ローラの上流側に用紙検出部材を配設し、この用紙検出部材が前記記録部材が送られてきたことを検出すると、前記駆動源により前記紙送りローラを回転させて、前記第１の紙送り動作を行うようにした構成とした。
【００１０】
【発明の実施の形態】
本発明のプリンタの紙送り機構を、例えばサーマルプリンタを基に図１〜図５を用いて説明する。また、従来の部品と同一のものは同一の記号を付与して説明する。
まず、図１に示すサーマルプリンタの概略構成は、下方側に樹脂材料等から成る筺体（図示せず）を構成する底板１が配設され、この底板１の上部に平坦状のゴム等から成るプラテン２が取付られている。
このプラテン２の図示左右には、紙ガイド３、４がそれぞれ配設され、後述する記録紙８を搬送する搬送経路Ｈが構成されている。
この搬送経路Ｈの上方側にはヘッド取付部材５が支持ピン５ａ、５ｂに取り付けられて上下動可能に配設されている。
また、ヘッド取付部材５の下面側で前記プラテン２の上方には、サーマルヘッド等から成る記録ヘッド６が取り付けられている。
この記録ヘッド６の図示左側には、後述する記録部材８が搬送経路Ｈに送られてきたことを検出する、光学式のセンサ等から成る用紙検出部材７が取り付けられている。
【００１１】
また、搬送経路Ｈには上流側から矢印Ｒ方向に、サーマル紙等から成る記録部材８が手差しで搬送されて来るようになっている。
前記搬送経路Ｈの紙ガイド４の下流側には、送られてきた記録部材８を下流側に搬送する紙送りローラ１１が配設されている。
この紙送りローラ１１は外周部がゴム等から成り、図２に示すように、紙送りローラ１１の回転軸１１ａに歯車部１１ｂが取り付けられ、この歯車部１１ｂは外周部に所定の数の歯山１１ｃが形成されている。
また、図２に示す紙送りローラ１１の図示左上方には中間歯車１２が配設され、この中間歯車１２の外周部に複数の歯山から成る歯車部１２ａが形成されている。この歯車部１２ａに前記紙送りローラ１１の歯車部１１ｂが噛み合った状態になっている。
【００１２】
また、中間歯車１２の図示左側には、モータ等から成る駆動源１３が配設され、この駆動源１３の回転軸１３ａに所定の歯数を有する駆動歯車１３ｂが取り付けられている。前記駆動源１３の回転が中間歯車１２を介して紙送りローラ１１に伝達されるようになっている。
前記紙送りローラ１１の図示下方には、この紙送りローラ１１に圧接すると共に、紙送りローラ１１の回転に従動して回転する従動ローラ１４が配設されている。
前記紙送りローラ１１と従動ローラ１４とに、記録部材８が手差し給紙されると、紙送りローラ１１が回転して、記録部材８が紙送りローラ１１と従動ローラ１４とに狭持され、下流側に搬送可能になっている。
前述のような紙送りローラ１１の回転トルクは、従動ローラ１４が圧接されていても、低トルクで回転するようになっているので、駆動源１３の駆動トルクを小さくすることができるようになっている。
【００１３】
このような構成の本発明のプリンタの紙送り機構で記録部材８の頭出しを行う動作は、第１と第２の紙送り動作からなり、この第１の紙送り動作は、記録部材８を手差しで搬送経路Ｈ内を矢印Ｒ方向に挿入する。
すると、前記記録部材８の先端部８ａが、用紙検出部材７の下部を経て、プラテン２と記録ヘッド６の間を通過し、紙送りローラ１１の外周部に当接する。
すると、用紙検出部材７が記録部材８を検出してＯＮして、駆動源１３を回転させて、中間歯車１２を矢印Ｃ方向に回転させ、紙送りローラ１１を矢印Ｄ方向に回転させる。
この紙送りローラ１１の矢印Ｄ方向への回転で、前記手差し給紙された記録部材８の先端部８ａが、紙送りローラ１１と従動ローラ１４とに狭持される。そして、紙送りローラ１１の矢印Ｄ方向への回転状態において、記録部材８を手差し給紙と紙送りローラ１１の回転とで、図２に示すように先端部８ａが紙送りローラ１１の下流側に若干搬送した後、紙送りローラ１１の回転を一時停止させて、第１の紙送り動作が終了する。
この第１の紙送り動作が終了したときの、中間歯車１２の歯車部１２ａに噛み合っている紙送りローラ１１の歯山１１ｃは、図３に示すように歯山１１ｃの右側壁にバックラッシュＢ２が発生した状態になっている。
このような、駆動源１３を回転させて中間歯車１２を矢印Ｃ方向に回転させたのに、紙送りローラ１１の歯山１１ｃの右側壁にバックラッシュＢ２が発生する理由は、前記紙送りローラ１１が回転状態でも、手差し給紙が継続され、この手差し給紙による記録部材８の挿入力で、紙送りローラ１１を矢印Ｄ方向に回転させようとする回転力が加わって、図３に示すようなバックラッシュＢ２が生じることになる。
【００１４】
前記第１の紙送り動作後、前記ヘッド取付部材５の内部の制御部材（図示せず）からの指示により、第２の紙送り動作を行う。
この第２の紙送り動作は、記録部材８から手を離した状態で、前記第１の紙送り動作と同じ回転方向の矢印Ｄ方向に紙送りローラ８を回転させて、記録部材８を図２に示す状態から、図４に示すように更に下流側に送る動作で、記録部材８の印字開始部（図示せず）を記録ヘッド６の下方まで送って、記録部材８の頭出しを行う。
この第２の紙送り動作では、紙送りローラ１１を回転させようとする力は中間歯車１２だけなので、図５に示すように紙送りローラ１１の歯山１１ｃの左側壁にバックラッシュＢ１が発生する。
前記第１と第２の紙送り動作で記録部材８の頭出し後、ヘッド取付部材５を降下させ、記録ヘッド６をプラテン２側に移動させ、記録部材８を記録ヘッド６とプラテン２とで圧接狭持して、記録ヘッド６で記録部材８に所望の画像を印刷する。
そして、紙送りローラ１１を矢印Ｄ方向に回転させ、印刷後の記録部材８を引っ張って、紙送りローラ１１の下流側に記録部材８を排出して、本発明のプリンタの紙送り機構による印刷が終了する。
【００１５】
本発明のプリンタの紙送り機構は、第１と第２の紙送り動作のどちらも、紙送りローラ１１を矢印Ｄ方向の同方向に回転させ、その後も矢印Ｄ方向にだけ紙送りローラ１１を回転させて、記録部材８に印刷するようにしているので、前記第２の動作から後は、図５に示すように、中間歯車１２の歯車部１２ａが、常に紙送りローラ１１の歯山１１ｃの右側壁に接した状態で、駆動源１３の回転が紙送りローラ１１に伝達されるので、歯山１１ｃの左側壁にバックラッシュＢ１があっても、紙送りローラ１１の回転を回転ムラ等のない回転を得ることができ、紙送りムラのない、安定した紙送り量での記録部材８の送りを行うことができる。
また、本発明の実施の形態では、サーマルプリンタを例に説明したが、本発明のプリンタの紙送り機構はサーマルプリンタに限定されるものでなく、その他のプリンタ、例えばインクジェットプリンタ等にも実施することが可能である
【００１６】
【発明の効果】
本発明のプリンタの紙送り機構は、紙送りローラの回転状態において、手差し給紙で前記記録部材を前記紙送りローラで下流側に若干搬送した後、前記紙送りローラの回転を一時停止させる第１の紙送り動作と、この第１の紙送り動作後、前記紙送りローラの回転で前記記録部材を下流側に送り、前記記録部材の印刷開始部を前記記録ヘッドまで送る第２の紙送り動作とで、前記記録部材の頭出しを行うようにしたので、常に駆動源を同方向に回転させて紙送りを行うことで、スループットを速くすることができる。また、前記第１と第２の紙送り動作で印刷品質にバックラッシュの影響がでない、送りムラのない安定した紙送りを行うことができ、高印刷品質を得ることができるプリンタの紙送り機構を提供することができる。
【００１７】
また、紙送りローラと駆動源とに歯車部を形成し、この搬送ローラと前記駆動源との間に中間歯車を配設し、前記駆動源の回転を前記中間歯車を介して前記紙送りローラに伝達するようにしたので、紙送りローラに対して駆動源の配設位置が限定されず、設計の自由度を増やすことができる。
【００１８】
また、前記搬送ローラの上流側に用紙検出部材を配設し、この用紙検出部材が前記記録紙が送られてきたことを検出すると、前記駆動源により前記紙送りローラを回転させて、前記第１と第２の紙送り動作を行うようにしたので、送られてきた記録部材を前記用紙検出部材で確実に検出することができ、記録部材が紙送りローラに送られてくると、確実に紙送りローラを回転させることができ、高精度の紙送りが可能である。
【図面の簡単な説明】
【図１】本発明のプリンタの紙送り機構を用いたプリンタの要部概略側面図。
【図２】本発明のプリンタの紙送り機構を説明する要部側面図。
【図３】本発明のプリンタの紙送り機構を説明する要部拡大図。
【図４】本発明のプリンタの紙送り機構を説明する要部側面図。
【図５】本発明のプリンタの紙送り機構を説明する要部拡大図。
【図６】従来のプリンタの紙送り機構を説明する要部側面図。
【符号の説明】
１底板
２プラテン
３、４紙ガイド
５ヘッド取付部材
５ａ、５ｂ支持ピン
６記録ヘッド
７用紙検出部材
８記録部材
８ａ先端部
１１紙送りローラ
１１ａ回転軸
１１ｂ歯車部
１１ｃ歯山
１２中間歯車
１３駆動源
１３ａ回転軸
１３ｂ駆動歯車
１４従動ローラ
Ｈ搬送経路
Ｋ紙送り機構[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper feeding mechanism of a printer that can easily remove backlash of a paper feeding roller that occurs when a recording paper is manually fed to a paper feeding roller.
[0002]
[Prior art]
As shown in FIG. 6, the conventional paper feed mechanism of a printer includes a paper feed roller 11, an intermediate gear 12 that meshes with a gear portion 11b of the paper feed roller 11, and a gear portion that meshes with a gear portion 12a of the intermediate gear 12. The driving source 13 is composed of a motor having a motor 13b, and a driven roller 14 that is in pressure contact with the paper feed roller 11 and rotates in accordance with the rotation of the paper feed roller 11.
In the operation of the paper feeding mechanism of the conventional printer having such a configuration, the recording member 8 is manually fed in the arrow R direction. Then, the drive source 13 is rotated in the arrow B direction, and the recording member 8 is slightly conveyed downstream by the paper feed roller 11 rotated in the arrow D direction via the intermediate gear 12.
[0003]
A minute gap (not shown) is generated in the tooth tip portion of the drive source 13, the intermediate gear 12, and the paper feed roller 11 in a state where the gear portions 11 a and 12 a 13 b are engaged with each other. Backlash occurs.
When printing is performed using the paper feed mechanism of a printer having such a backlash, the rotation of the paper feed roller 11 is varied by the size of the backlash, and the recording member 8 is displaced, and printing is performed on the recording member. There was a problem that the print quality of the obtained image deteriorated.
In order to eliminate the backlash of the gear as described above, a highly accurate gear without variation in tooth shape and size is required. However, since such a high-precision gear is very expensive, it has been difficult to use in a small printer or the like that requires a low price.
[0004]
Therefore, the operation of the paper feeding mechanism of the conventional printer that does not deteriorate the print quality even if backlash occurs, manually feeds the recording member 8 to the paper feeding roller 11 side and rotates the drive source 13 in the direction of arrow B. Then, the paper feed roller 11 is rotated in the direction of arrow D via the intermediate gear 12, and the recording member 8 in the manual feed state is slightly conveyed to the downstream side, and the rotation of the drive source 13 is temporarily stopped.
Thereafter, the rotation of the drive source 13 is reversed in the direction of arrow E, and the paper feed roller 3 is rotated in the direction of arrow G via the intermediate gear 12 until the recording member 8 is not detached from the paper feed roller 11. Return slightly to the upstream side in the L direction.
[0005]
Next, the drive source 13 is rotated again in the direction of arrow B, and the paper feed roller 11 is rotated in the direction of arrow D by a predetermined amount via the intermediate gear 12 to cue the recording member 8.
After cueing the recording member 8, a desired image is printed on the recording member 8, the paper feed roller 11 is rotated in the direction of arrow D, and the printed recording member 8 is discharged to the downstream side of the paper feed roller 11. .
As described above, the paper feeding mechanism of the conventional printer is such that the recording member 8 is slightly conveyed downstream of the paper feeding roller 11 by manual feeding and the paper feeding roller 11 rotated in the direction of arrow D, and then the paper feeding roller 11. Is once reversed in the direction of arrow G, and the recording member 8 is returned to the upstream side in the direction of arrow L.
Thereafter, the paper feed roller 11 is rotated again in the direction of the arrow D, and the recording member 8 is conveyed to the downstream side so that the printed image is not affected by backlash.
[0006]
[Problems to be solved by the invention]
However, in the conventional paper feeding mechanism as described above, when the recording member 8 is fed to the paper feeding roller 11, the paper feeding roller 11 is divided into an operation for feeding the recording member 8 to the downstream side and an operation for returning the recording member 8 to the upstream side. Therefore, there is a problem that the time (throughput) from the start of conveyance of the recording member 8 to the end of printing becomes long.
The present invention provides a paper feed mechanism for a printer that can eliminate the influence of backlash of the paper feed roller 11 and always obtain a stable and high-quality printed image, improve the throughput, and shorten the printing time. It is a thing.
[Means for Solving the Problems]
Paper feeding mechanism of the printer of the present invention as a first means of order to that to solve the above problem, a paper feeding roller rotatable, driven by the rotation of the paper feed roller co When pressed against the paper feed roller Driven roller, a recording member that is nipped and conveyed by the paper feeding roller and the driven roller, a recording head that prints a desired image on the recording member, and the paper feeding roller. A drive source,
Before SL paper feed roller after transporting slightly downstream in the rotation of the paper feed roller the recording member is rotated with manual feed of the paper feed roller in the state of the driven roller is pressed against the paper feed roller A first paper feeding operation for temporarily stopping the rotation of the recording member, and after the first paper feeding operation, the recording member is fed further downstream by the rotation of the paper feeding roller, and the print start portion of the recording member is moved to the recording The recording member is cued in the second paper feeding operation for feeding to the head.
[0008]
Further, the paper feeding mechanism of the printer of the present invention, the gear portion is formed in said driving source and said paper feed roller, the drive source and the Kamioku roller as a second means of order to you solve the problems An intermediate gear is disposed between and the rotation of the drive source is transmitted to the paper feed roller via the intermediate gear.
[0009]
Further, the paper feeding mechanism of the printer of the present invention as a third means of order to that to solve the above problems, the paper feeding the paper detection member is disposed upstream of the roller, the paper detection member is the recording member Is detected, the paper feed roller is rotated by the drive source to perform the first paper feed operation.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The paper feed mechanism of the printer of the present invention will be described with reference to FIGS. Also, the same parts as those of the conventional parts will be described with the same symbols.
First, in the schematic configuration of the thermal printer shown in FIG. 1, a bottom plate 1 constituting a housing (not shown) made of a resin material or the like is disposed on the lower side, and a flat rubber or the like is formed on the top of the bottom plate 1. A platen 2 is attached.
Paper guides 3 and 4 are disposed on the left and right sides of the platen 2 to form a transport path H for transporting a recording paper 8 to be described later.
On the upper side of the transport path H, a head mounting member 5 is mounted on support pins 5a and 5b so as to be movable up and down.
A recording head 6 made of a thermal head or the like is mounted on the lower surface side of the head mounting member 5 and above the platen 2.
On the left side of the recording head 6 shown in the drawing, a sheet detecting member 7 composed of an optical sensor or the like for detecting that a recording member 8 (described later) is sent to the transport path H is attached.
[0011]
Further, the recording member 8 made of thermal paper or the like is manually conveyed to the conveyance path H in the direction of arrow R from the upstream side.
On the downstream side of the paper guide 4 in the transport path H, a paper feed roller 11 for transporting the sent recording member 8 to the downstream side is disposed.
The outer periphery of the paper feed roller 11 is made of rubber or the like, and as shown in FIG. 2, a gear portion 11b is attached to the rotating shaft 11a of the paper feed roller 11, and the gear portion 11b has a predetermined number of teeth on the outer periphery. A mountain 11c is formed.
Further, an intermediate gear 12 is disposed on the upper left side of the paper feed roller 11 shown in FIG. 2, and a gear portion 12 a made up of a plurality of teeth is formed on the outer peripheral portion of the intermediate gear 12. The gear portion 11a of the paper feed roller 11 is engaged with the gear portion 12a.
[0012]
A drive source 13 composed of a motor or the like is disposed on the left side of the intermediate gear 12 in the drawing, and a drive gear 13b having a predetermined number of teeth is attached to a rotation shaft 13a of the drive source 13. The rotation of the drive source 13 is transmitted to the paper feed roller 11 via the intermediate gear 12.
Below the paper feed roller 11, a driven roller 14 that is in pressure contact with the paper feed roller 11 and that rotates following the rotation of the paper feed roller 11 is disposed.
When the recording member 8 is manually fed to the paper feed roller 11 and the driven roller 14, the paper feed roller 11 rotates and the recording member 8 is held between the paper feed roller 11 and the driven roller 14. It can be transported downstream.
The rotational torque of the paper feed roller 11 as described above can be rotated with a low torque even when the driven roller 14 is in pressure contact, so that the drive torque of the drive source 13 can be reduced. ing.
[0013]
The operation of cueing the recording member 8 by the paper feeding mechanism of the printer of the present invention having the above-described configuration includes first and second paper feeding operations. The inside of the conveyance path H is manually inserted in the direction of arrow R.
Then, the leading end portion 8 a of the recording member 8 passes between the platen 2 and the recording head 6 through the lower portion of the paper detection member 7 and comes into contact with the outer peripheral portion of the paper feed roller 11.
Then, the sheet detection member 7 detects the recording member 8 and turns ON, rotates the drive source 13, rotates the intermediate gear 12 in the arrow C direction, and rotates the paper feed roller 11 in the arrow D direction.
By rotation of the paper feed roller 11 in the direction of arrow D, the leading end 8 a of the manually fed recording member 8 is held between the paper feed roller 11 and the driven roller 14. When the paper feed roller 11 is rotated in the direction of arrow D, the leading end 8a is located downstream of the paper feed roller 11 as shown in FIG. Then, the rotation of the paper feed roller 11 is temporarily stopped, and the first paper feed operation is completed.
When the first paper feeding operation is completed, the tooth crest 11c of the paper feeding roller 11 meshed with the gear portion 12a of the intermediate gear 12 is backlash B2 on the right wall of the tooth crest 11c as shown in FIG. Has occurred.
The reason why the backlash B2 occurs on the right side wall of the tooth crest 11c of the paper feed roller 11 even when the drive source 13 is rotated and the intermediate gear 12 is rotated in the direction of arrow C is that the paper feed roller 11 in the rotation state, the manual feed is continued, with the insertion force of the recording member 8 according to this manual feeding, the rotational force is applied to rotate the paper feed roller 11 in the direction of arrow D, Figure 3 As shown, backlash B2 occurs.
[0014]
After the first paper feeding operation, a second paper feeding operation is performed according to an instruction from a control member (not shown) inside the head mounting member 5.
In the second paper feeding operation, with the hand released from the recording member 8, the paper feeding roller 8 is rotated in the direction of the arrow D in the same rotational direction as the first paper feeding operation, so that the recording member 8 is moved. From the state shown in FIG. 2, in the operation of sending further downstream as shown in FIG. 4, the printing start portion (not shown) of the recording member 8 is sent to the lower part of the recording head 6 to cue the recording member 8. .
In this second paper feeding operation, the intermediate gear 12 is the only force to rotate the paper feeding roller 11, so that a backlash B1 occurs on the left side wall of the tooth crest 11c of the paper feeding roller 11 as shown in FIG. To do.
After the recording member 8 is cued by the first and second paper feeding operations, the head mounting member 5 is lowered, the recording head 6 is moved to the platen 2 side, and the recording member 8 is moved between the recording head 6 and the platen 2. A desired image is printed on the recording member 8 by the recording head 6 with the pressure contact.
Then, the paper feed roller 11 is rotated in the direction of arrow D, the printed recording member 8 is pulled, and the recording member 8 is discharged to the downstream side of the paper feed roller 11, and printing by the paper feed mechanism of the printer of the present invention. Ends.
[0015]
The paper feeding mechanism of the printer of the present invention rotates the paper feeding roller 11 in the same direction as the arrow D in both the first and second paper feeding operations, and thereafter the paper feeding roller 11 is moved only in the direction of the arrow D. Since the printing is performed on the recording member 8 after the rotation, the gear portion 12a of the intermediate gear 12 always has the tooth crest 11c of the paper feed roller 11 after the second operation as shown in FIG. Since the rotation of the drive source 13 is transmitted to the paper feed roller 11 in contact with the right side wall, even if there is a backlash B1 on the left side wall of the tooth crest 11c, the rotation of the paper feed roller 11 is uneven. Rotation can be obtained, and the recording member 8 can be fed at a stable paper feed amount with no paper feed unevenness.
In the embodiment of the present invention, the thermal printer has been described as an example. However, the paper feeding mechanism of the printer of the present invention is not limited to the thermal printer, and may be implemented in other printers such as an ink jet printer. It is possible [0016]
【The invention's effect】
The paper feed mechanism of the printer according to the present invention is configured to temporarily stop the rotation of the paper feed roller after the recording member is transported slightly by the paper feed roller to the downstream side by manual paper feed in the rotation state of the paper feed roller. 1 paper feeding operation, and after this first paper feeding operation, the recording member is sent to the downstream side by the rotation of the paper feeding roller, and the second paper feeding is sent to the recording head by the print start portion of the recording member. Since the recording member is cued in the operation, the throughput can be increased by always feeding the paper while rotating the drive source in the same direction. In addition, the paper feeding mechanism of the printer which can perform stable paper feeding without unevenness in feeding without affecting the printing quality by the first and second paper feeding operations, and can obtain high printing quality. Can be provided.
[0017]
Further, a gear portion is formed between the paper feed roller and the drive source, an intermediate gear is disposed between the transport roller and the drive source, and the rotation of the drive source is transmitted through the intermediate gear to the paper feed roller. Since the position of the drive source is not limited with respect to the paper feed roller, the degree of freedom in design can be increased.
[0018]
Further, a paper detection member is disposed on the upstream side of the transport roller, and when the paper detection member detects that the recording paper has been fed, the paper feed roller is rotated by the drive source, and the first Since the first and second paper feeding operations are performed, the sent recording member can be reliably detected by the paper detection member, and when the recording member is sent to the paper feeding roller, it is ensured. The paper feed roller can be rotated, and high-precision paper feed is possible.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a main part of a printer using a paper feeding mechanism of a printer of the present invention.
FIG. 2 is a side view of an essential part for explaining a paper feed mechanism of a printer according to the present invention.
FIG. 3 is an enlarged view of a main part for explaining the paper feeding mechanism of the printer of the present invention.
FIG. 4 is a side view of an essential part for explaining a paper feeding mechanism of a printer according to the present invention.
FIG. 5 is an enlarged view of a main part for explaining a paper feeding mechanism of the printer of the present invention.
FIG. 6 is a side view of a main part for explaining a paper feeding mechanism of a conventional printer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bottom plate 2 Platen 3, 4 Paper guide 5 Head attachment member 5a, 5b Support pin 6 Recording head 7 Paper detection member 8 Recording member 8a Tip part 11 Paper feed roller 11a Rotating shaft 11b Gear part 11c Teeth 12 Intermediate gear 13 Drive source 13a Rotating shaft 13b Drive gear 14 Driven roller H Transport path K Paper feed mechanism

Claims

A rotatable paper feed roller, and conveyed this when pressed against the paper feed roller and a driven roller rotated by the rotation of the paper feed roller co, is sandwiched between the paper feed roller and the driven roller A recording member, a recording head for printing a desired image on the recording member, and a drive source for rotating the paper feed roller,
Before SL paper feed roller after transporting slightly downstream in the rotation of the paper feed roller the recording member is rotated with manual feed of the paper feed roller in a state in which the driven roller was pressed against the paper feed roller A first paper feeding operation for temporarily stopping the rotation of the recording member, and after the first paper feeding operation, the recording member is fed further downstream by the rotation of the paper feeding roller, and the print start portion of the recording member is moved to the recording A paper feeding mechanism for a printer, wherein the recording member is cued in a second paper feeding operation for feeding to the head.

A gear portion is formed between the paper feed roller and the drive source, an intermediate gear is disposed between the paper feed roller and the drive source, and rotation of the drive source is performed via the intermediate gear. 2. The paper feeding mechanism for a printer according to claim 1, wherein the paper feeding mechanism is transmitted to a roller.

A paper detection member is disposed on the upstream side of the paper feed roller, and when the paper detection member detects that the recording member has been fed, the paper feed roller is rotated by the drive source, and the first 3. The paper feeding mechanism for a printer according to claim 1, wherein the paper feeding operation is performed.