JP2011037044A - Printing mechanism and thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing mechanism in which an ink ribbon adhering to a paper is peeled appropriately from the paper, smooth conveyance of a paper and an ink ribbon is attained, and occurrence of horizontal streaks or reverse transcription can be prevented. <P>SOLUTION: The printing mechanism 3 includes a peeling unit 35 which is provided closer to the winding side of an ink ribbon 33 than the pressure contact point P of a thermal head 31 and a platen roller 32 in order to peel a paper S and the ink ribbon 33 passed the pressure contact point P. The peeling unit 35 consists of a peeling unit body 351 which presses the ink ribbon 33 and the paper S from the ink ribbon 33 side, and a peeling backup member 352 provided at a position facing the peeling unit body 351 in order to back up the ink ribbon 33 and the paper S from the paper S side. A gap 35S larger than the total thickness of some paper S and the ink ribbon 33 when they are superimposed on each other is formed between the peeling unit body 351 and the peeling backup member 352. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a printing mechanism and a thermal printer.

  2. Description of the Related Art Conventionally, there is known a thermal printer that uses the heat of a thermal head to transfer and print sublimation ink or melt ink applied to an ink ribbon onto a sheet. In this type of thermal printer, the thermal head is pressed against the platen roller side against the paper and the ink ribbon superimposed in the thickness direction on the platen roller, and the thermal head is heated while the ink ribbon is in close contact with the paper. Thus, a desired image or the like can be printed on the paper by thermally transferring the ink onto the paper.

  The ink ribbon subjected to the thermal transfer process is separated from the paper by a peeling member (for example, a peeling roller) provided closer to the paper feed unit than the thermal head, and is wound around the take-up ribbon core. Usually it is.

  However, even with a conventional thermal printer equipped with such a peeling member, the ink ribbon does not peel off from the paper properly, and the ink ribbon side peels off and the extra ink is transferred to the paper. There has been a problem that the print quality is deteriorated.

  As a result of careful consideration of the above-mentioned problems and intensive studies on the peeling action of the ink ribbon on the paper, the present inventors have found that many conventional thermal printers peel off the paper and ink ribbon that are in close contact with a peeling roller or the like. A configuration is adopted in which the ink ribbon is peeled off from the paper that is pressed only from the ink ribbon side by the member and the paper side is not backed up at all and is in an unstable state. It has been found that this is a factor that the ribbon cannot be peeled off properly. In addition, when the ink ribbon cannot be properly peeled from the paper, unnecessary vibrations are given to peripheral mechanism parts (such as a thermal head) of the peeling member, which also causes a decrease in print quality. It is thought that.

  Patent Document 1 discloses an aspect in which a peeling member (peeling roller or peeling plate) is configured to be movable between a position separated from the platen roller and a position where the peeling member is pressed against the platen roller. In this aspect, when the peeling member is set at a position where it is pressed against the platen roller, the overlapped paper and ink ribbon can be backed up from the paper side by the platen roller.

JP-A-5-208533

  However, since the peeling member is pressed against the platen roller, it is difficult to smoothly convey the paper and the ink ribbon between the peeling member and the platen roller. In addition, the ink ribbon subjected to the thermal transfer process is used as the paper. When it is attempted to forcibly pass between the peeling member and the platen roller that are in pressure contact with each other, excessive pressure acts on the ink ribbon and the paper, and the ink once transferred to the paper A phenomenon called reverse transfer back to the ribbon is also likely to occur.

  The present invention has been made paying attention to such a problem. The main object of the present invention is to appropriately peel off the ink ribbon that is in close contact with the paper after passing through the thermal head from the paper so that an excess amount is left on the paper. A printing mechanism that can prevent or suppress a decrease in print quality due to ink being transferred from the ribbon, and that can smoothly transport the paper and the ink ribbon and prevent problems such as reverse transfer, and the printing mechanism An object of the present invention is to provide a thermal printer having such a printing mechanism.

  In other words, the printing mechanism according to the present invention is provided on the side where the ink ribbon is wound up with respect to the ink ribbon, the thermal head and the platen pressed against each other via the ink ribbon and the paper, and the press-contact portion between the thermal head and the platen. And a peeling portion that peels off the ink ribbon that has passed through the pressure contact portion and the paper. In the printing mechanism according to the present invention, the peeling portion is provided at a position facing the peeling portion main body, the peeling portion main body that presses the ink ribbon and the paper from the ink ribbon side, and the ink ribbon and the paper from the paper side. A separation backup member for backup is used, and a gap larger than the total thickness dimension of the overlapped paper and ink ribbon is formed between the separation portion main body and the separation backup member.

  In such a case, the paper and the ink ribbon that are in close contact are pressed from the ink ribbon side by the peeling unit main body, and the paper and the ink ribbon are backed up from the paper side by the peeling backup member, and are in a stable state. Since the ink ribbon is peeled off from the paper, the ink ribbon can be peeled off properly from the paper, eliminating the problem of excess ink being transferred to the paper due to surface peeling on the ink ribbon side. can do. By appropriately performing the ink ribbon peeling process on the paper, unnecessary vibrations are not given to the peripheral mechanism parts of the peeling part such as the thermal head, and the deterioration of the printing quality due to the vibration can be avoided. .

  Furthermore, the printing mechanism of the present invention forms a gap larger than the total thickness dimension of the overlapped paper and ink ribbon between the peeling portion main body and the peeling backup member. In addition, the ink ribbon can be smoothly conveyed between the peeling portion main body and the peeling backup member.

  And, by forming a predetermined gap between the peeling portion main body and the peeling backup member in this way, excessive pressure acts on the paper and the ink ribbon that pass between the peeling portion main body and the peeling backup member. As a result, it is possible to prevent / suppress the occurrence of reverse transfer in which the ink once transferred to the paper returns to the ink ribbon, and to perform high-quality print processing.

  In the printing mechanism of the present invention, the peeling backup member can be configured by using a platen, or can be configured by a member separate from the platen. In particular, when a peeling backup member is configured using a platen roller, it is possible to share parts, and it is possible to reduce the number of parts and simplify the structure.

  The thermal printer according to the present invention is characterized in that the printing mechanism having the above-described configuration is disposed between the paper feeding unit and the paper discharging unit. Such a thermal printer exhibits various effects obtained by the above-described printing mechanism and is excellent in practicality.

  According to the present invention, the paper is held by the peeling backup member during the peeling process and is in a stable state, and the ink ribbon can be appropriately peeled from the stable paper. As a result, it is possible to prevent or suppress unnecessary ink from adhering (transferring) to the paper, and to smoothly carry the paper and the ink ribbon to the peeling portion, preventing problems such as reverse transfer, The print quality can be improved.

1 is a schematic diagram of an internal configuration of a thermal printer including a printing mechanism according to an embodiment of the present invention. FIG. 2 is an external view of a thermal printer according to the embodiment. The X direction arrow directional view in FIG. The principal part enlarged view of FIG. The figure which shows the modification of the thermal printer which concerns on the embodiment corresponding to FIG.

  The thermal printer 1 according to the present embodiment is a sublimation type printer that performs sublimation print (see FIG. 3) processing on a sheet S as shown in FIGS. 1 to 3. As shown in FIG. 1, the sublimation printer 1 includes a paper feed unit 2, a printing mechanism 3 that performs sublimation print processing on the surface Sa of the paper S supplied from the paper feed unit 2, and a paper discharge unit 4. (Specifically, a paper discharge port 41 and a paper discharge tray 42 shown in FIG. 2) and a paper transport mechanism that transports the paper S along a transport path formed between the paper feed unit 2 and the paper discharge unit 4. 5. The sublimation printer 1 includes at least a paper feed unit 2, a printing mechanism 3, and a paper transport mechanism 5 in a common casing C, and a paper discharge port 41 and a paper discharge tray 42 that constitute the paper discharge unit 4. Is exposed to the outside of the housing C.

  The paper feed unit 2 can accommodate the paper S wound in a roll shape. The paper discharge unit 4 discharges the paper S, which has been subjected to a desired print process by the printing mechanism 3, as a cut paper cut to a predetermined size from the paper discharge port 41 to the outside of the housing C, and onto the paper discharge tray 42. It can be placed in a stacked state.

  The paper transport mechanism 5 that transports the paper S between the paper feed unit 2 and the paper discharge unit 4 has a paper feed side feed roller arranged in order from the paper feed unit 2 side toward the paper discharge unit 4 side. 51, the first pinch roller 52, the feed roller 53 and the second pinch roller 54, and the paper discharge side feed roller 55 and the third pinch roller 56. A pair of the paper feed side feed roller 51 and the first pinch roller 52 and a pair of the feed roller 53 and the second pinch roller 54 are arranged on the paper feed unit 2 side with respect to the printing mechanism 3, and the paper discharge side feed roller 55. And the third pinch roller 56 are arranged closer to the paper discharge unit 4 than the printing mechanism 3. The feed roller 53 discharges the paper S when the paper S is transported from the paper feed unit 2 side toward the paper discharge unit 45 side (in the direction of arrow A in FIG. 1) and when the printing mechanism 3 performs the printing process. It can be rotated forward and backward in the printing direction (in the direction of arrow B in FIG. 1) for conveying from the paper portion 45 side toward the paper feeding portion 2 side. Further, the paper feed side feed roller 51 and the paper discharge side feed roller 55 also rotate forward and backward as appropriate in response to the feed roller 53. Each pinch roller (first pinch roller 52, second pinch roller 54, third pin The pinch rollers 56) are in contact with the paper feed side feed roller 51, the feed roller 53, and the paper discharge side feed roller 55 through the paper S, respectively (the paper feed side feed roller 51, the feed roller 53, the discharge roller 53). It rotates following the rotational drive of the paper-side feed roller 55). Further, in the present embodiment, a paper discharge side cutter unit 57 that cuts the paper S that has undergone the thermal transfer printing process at least at each print screen boundary is disposed between, for example, the paper discharge side feed roller 55 and the paper discharge unit 4. is doing.

  As shown in FIGS. 1, 3, and 4, the printing mechanism 3 performs thermal printing on the thermal head 31, the platen roller 32 disposed at a position facing the thermal head 31, the ink ribbon 33, and the ink ribbon 33. An ink ribbon transport mechanism 34 that transports between the head 31 and the platen roller 32, a print control unit (not shown) that controls at least the operation of the thermal head 31, and a pressure contact between the thermal head 31 and the platen roller 32, that is, A peeling portion that peels off the paper S and the ink ribbon 33 that are in close contact with each other beyond the thermal transfer printing position P (see FIG. 4 in which the paper S and the ink ribbon 33 are omitted). 35 is provided.

  The thermal head 31 is a well-known one that performs printing on the paper S by causing the heat generating elements to generate heat. In this embodiment, the thermal head 31 is set so as to be movable between a position where the paper S can be sandwiched between the platen roller 32 and a position where the thermal head 31 cannot be sandwiched by a head drive motor (not shown).

  The platen roller 32 can sandwich the paper S with the thermal head 31 and has a function of sequentially transporting the paper S while rotating. Accordingly, the platen roller 32 bears a part of the function of the paper transport mechanism 5. The platen roller 32 can rotate in the forward and reverse directions in synchronization with the feed roller 53.

  The ink ribbon 33 is obtained by applying, for example, yellow, magenta, and cyan inks to a long base film. The yellow, magenta, and cyan inks applied to the base film are formed using a dye that sublimes by heat.

  The ink ribbon transport mechanism 34 includes a supply-side ribbon core 341 around which an unused ink ribbon 33 (in which a base film is coated with ink) is wound, and a used ink ribbon 33 (part of ink from the base film or A ribbon-side ribbon core 342 that winds up, a supply-side ribbon guide 343 that guides the ink ribbon 33 unwound from the supply-side ribbon core 341 to the thermal head 31 side, and after passing through the thermal head 31 A take-up ribbon guide 344 for guiding the ink ribbon 33 peeled from the paper S to the take-up ribbon core 342 side is provided. The supply-side ribbon core 341 and the supply-side ribbon guide 343 are arranged on the paper discharge unit 4 side with respect to the thermal head 31, and the take-up side ribbon core 342 and the take-up side ribbon guide 344 are arranged on the paper supply unit 2 side with respect to the thermal head 31. Is done. Therefore, the ink ribbon 33 wound around the supply-side ribbon core 341 is unwound to the thermal head 31 side by the supply-side ribbon guide 343 and the take-up side ribbon guide 344, and is subjected to the sublimation printing process, and then the take-up side. The ribbon core 342 is sequentially wound up. In this embodiment, the ink ribbon 33 and the ink ribbon transport mechanism 34 are unitized and configured to be detachable from the thermal head 31 and the platen roller 32.

  The peeling unit 35 is disposed closer to the paper feed unit 2 than the thermal head 31, and has a peeling unit main body 351 that presses the ink ribbon 33 that is in close contact with each other after the thermal transfer process from the ink ribbon 33 side, and a peeling unit main body 351. And a peeling backup member 352 that backs up the paper S and the ink ribbon 33 from the paper S side.

  In the present embodiment, the peeling unit main body 351 is configured using, for example, a roller, and is in a position where it does not interfere with the thermal head 31, and the thermal head 31 and the platen roller 32 are mutually connected via the paper S and the ink ribbon 33. The pressure contact portion, that is, the thermal transfer printing position P is arranged as close as possible to the pressure contact portion. As such a peeling backup member 352, the platen roller 32 is utilized especially in this embodiment. Specifically, a portion of the rotating platen roller 32 that is closer to the paper feed unit 2 than the thermal transfer printing position P is caused to function as the peeling backup member 352.

  And the peeling part 35 which concerns on this embodiment forms the clearance gap 35S of a predetermined dimension between the peeling part main body 351 and the peeling backup member 352, as shown in FIG. This gap 35S is a value obtained by adding the thickness dimension of the thickest ink ribbon 33 among the various applicable ink ribbons 33 to the thickness dimension of the thickest paper S among the various papers S that can be printed by the thermal printer 1. It has a larger area. For example, in the present embodiment, the gap 35S is set to a value obtained by adding several μm to the thickness dimension of the paper S.

  Next, the operation and action of the thermal printer 1 according to the present embodiment, particularly the operation and action of the printing mechanism 3 will be described.

  First, the paper S wound in a roll shape by the paper feeding unit 2 is sequentially passed between the paper feeding side feed roller 51 and the first pinch roller 52 and between the feed roller 53 and the second pinch roller 54. To the printing mechanism 3. At this time, the paper transport mechanism 5 rotates the feed roller 53 in the feed direction (the direction of arrow A in FIG. 1). Further, in the present embodiment, when the feed roller 53 is rotationally driven in the delivery direction (the direction of arrow A in FIG. 1), the paper S cannot be sandwiched between the thermal head 31 of the printing mechanism 3 and the platen roller 32. The sheet S is placed in a standby state, and the paper S is smoothly conveyed. Then, the paper S is passed between the thermal head 31 and the platen roller 32 as much as the print processing is performed, and sent to the paper discharge unit 4 side, and the paper is fed out of the print setting area (print screen) on the surface Sa of the paper S. The end portion on the side of the portion 2 (this end portion is not cut at that time and is a portion continuous with the paper S wound in a roll shape in the paper feeding portion 2) passes through the platen roller 32. At the time of passing or passing, the thermal head 31 of the printing mechanism 3 moves to a position where the paper S can be sandwiched with the platen roller 32, while the paper transport mechanism 5 moves the feed roller 53 in the printing direction (FIG. 1). The paper S is conveyed in the direction of the arrow B in FIG.

  The printing mechanism 3 prints (forms) a color image on each print screen on the surface Sa of the paper S by sublimating yellow, magenta, and cyan inks by the heat of the thermal head 31. At this time, it is possible to perform gradation printing by changing the print density level by adjusting the temperature of the thermal head 31, and to print a high-quality color image on each print screen on the surface Sa of the paper S. Is possible. The temperature control and operation of the thermal head 31 are controlled by the print controller.

  Then, the ink ribbon 33 that has been subjected to the thermal transfer process is attached to and closely adhered to the paper S, and passes through the gap 35 </ b> S formed between the peeling portion main body 351 and the peeling backup member 352. At that time, the peeling unit main body 351 presses the ink ribbon 33 and the paper S from the ink ribbon 33 side, and the peeling backup member 352 backs up the ink ribbon 33 and the paper S from the paper S side. Is pressed against the peeling portion main body 351 in a stable state. As a result, the surface peeling of the ink on the ink ribbon 33 hardly occurs, and the reverse transfer phenomenon in which the ink transferred to the paper S returns to the ink ribbon 33 can be suppressed / prevented.

  After the thermal transfer printing process by the printing mechanism 3 is finished, the paper transport mechanism 5 rotates the feed roller 53 in the feed direction (the direction of arrow A in FIG. 1) to feed the paper S to the paper discharge side feed roller 55 and the third. The paper is passed between the pinch rollers 56 and sequentially conveyed to the paper discharge unit 4 side. The thermal printer 1 according to the present embodiment discharges the sheet S from the sheet discharge port 41 of the sheet discharge unit 4 to the outside of the housing C in a state where the sheet S is cut for each print screen by the sheet discharge side cutter unit 57. It is set so that S can be held in a state of being stacked on the paper discharge tray 42.

  As described above, the printing mechanism 3 according to the present embodiment is configured to remove the peeling unit 35 from the ink ribbon 33 side from the ink ribbon 33 and the paper S, and the ink ribbon 33 and the paper S from the paper S side. Since the backup member 352 for backup is used, the ink ribbon 33 can be held in a stable state when the ink ribbon 33 is peeled from the paper S, and the surface peeling of the ink ribbon 33 is prevented. It is possible to suppress the peeling process accurately and to perform a high quality printing process. In addition, since the peeling portion 35 according to the present embodiment forms a gap 35S larger than the total thickness dimension of the paper S and the ink ribbon 33 between the peeling portion main body 351 and the peeling backup member 352, the paper S The ink ribbon 33 adhered and adhered to the paper can be smoothly conveyed together with the paper S between the peeling portion main body 351 and the peeling backup member 352. As a result, there is a problem that occurs if the peeling part main body 351 is pressed against the peeling backup member 352, that is, when the paper is forcibly passed between the peeling part main body and the peeling backup member that are in close contact with each other without a gap. It is possible to prevent a problem that reverse transfer occurs in which the thermally transferred ink returns to the ink ribbon.

  In addition, this invention is not limited to embodiment mentioned above. For example, in the above-described embodiment, the mode in which the platen roller also functions as a separation backup member is illustrated from the viewpoint of commonality of members and simplification of the structure. However, the separation backup is performed using a member separate from the platen roller. You may comprise a member. As an example, as shown in FIG. 5, the peeling backup member according to the present invention may be configured by a roller X352 provided at a position facing the peeling portion main body X351 and backing up the ink ribbon 33 and the paper S from the paper S side. I do not care. In FIG. 5, parts corresponding to those shown in FIG. Although not clearly shown in the figure, between the peeling portion main body X351 and the peeling backup member X352, as in the above-described embodiment (particularly FIG. 4), the total thickness of the paper S and the ink ribbon 33 is determined. A large gap is formed.

  Moreover, you may apply things other than a roller, for example, a plate-shaped thing, as a peeling part main body.

  Furthermore, the size of the gap formed between the peeling portion main body and the peeling backup member may be changed according to the thickness of the paper or the thickness of the ink ribbon. Specifically, when the peeling unit main body is configured to be movable in a direction in which it is in contact with or separated from the peeling backup member, or when a separate member from the platen is used as the peeling backup member, this peeling backup is used. The size of the gap can be appropriately changed by configuring the member so as to be movable in a direction in which the member comes in contact with and separates from the peeling portion main body.

  Further, a thermal printer including a plurality of printing mechanisms shown in the above-described embodiments and modifications may be used. Further, in addition to a thermal printer that sublimates ink, a printing mechanism that exhibits the above-described structure and effects may be applied to various thermal printers having an ink ribbon, such as a type that melts ink.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Thermal printer, sublimation type printer 2 ... Paper feed part 3 ... Printing mechanism 31 ... Thermal head 32 ... Platen (platen roller)
33 ... Ink ribbon 35, X35 ... Peeling part 351, X351 ... Peeling part main body 352, X352 ... Peeling backup member 35S ... Gap 4 ... Paper discharge part P ... Thermal transfer print position (pressure contact part)
S ... paper

Claims (3)

An ink ribbon, a thermal head and a platen that are in pressure contact with each other via the ink ribbon and the paper, and a portion that winds the ink ribbon from the pressure contact portion between the thermal head and the platen, and passed through the pressure contact portion. A printing mechanism having a peeling portion for peeling the ink ribbon from the paper,
The peeling portion is
A peeling unit main body for pressing the ink ribbon and the paper from the ink ribbon side;
A peeling backup member provided at a position facing the peeling unit main body and backing up the ink ribbon and paper from the paper side;
A printing mechanism, wherein a gap larger than a total thickness dimension of the overlapped paper and ink ribbon is formed between the peeling portion main body and the peeling backup member. The printing mechanism according to claim 1, wherein the peeling backup member is a member using the platen or a member separate from the platen. A thermal printer comprising the printing mechanism according to claim 1 disposed between a paper feeding unit and a paper ejection unit.

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