JP2010052349A - Printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep the left and right balance of a power transmission means which transmits power to a platen roller. <P>SOLUTION: An printing apparatus includes: an apparatus body; a thermal head provided in the apparatus body for printing on a paper sheet; the platen roller 5 supporting the paper sheet printed by the thermal head; a drive motor 6 provided in the apparatus body at a position below the roller surface of the platen roller 5 and opposed to the roller surface; and the power transmission means 11 which transmits the power of the drive motor 6 to both ends of the platen roller 5 via first and second power transmission systems 11a and 11b so as to rotate the roller. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printing apparatus used for POS, ECR, barcode, lightweight device, and the like, and more particularly, to a technique for improving the stability and improvement of a recording medium conveyance mechanism.

This type of printing apparatus includes a print head that presses and prints on a recording medium, a platen roller that supports the recording medium to which the print head is pressed, and a drive mechanism that rotationally drives the platen roller. Has been. The drive mechanism includes a drive motor and a gear train as a power transmission mechanism that transmits power of the drive motor to both ends of the platen roller (see, for example, Patent Document 1).
JP 2001-38972 A

  However, in the prior art, a drive motor is installed on one of the left and right ends of the roller shaft of the platen roller, and the drive force of the drive motor is first transmitted to a gear attached to one end of the roller shaft. , And transmitted to a gear attached to the other end of the roller shaft.

  For this reason, it becomes difficult to balance the power transmitted to the left and right of the platen roller, the conveyance of the recording medium becomes unstable, and the contact pressure between the thermal head and the platen roller is uniform along the axial direction. Therefore, there is a problem that good print image quality cannot be obtained.

  The present invention has been made paying attention to the above circumstances, and an object of the present invention is to provide a printing apparatus which can balance the left and right of the power transmission means for transmitting power to the platen roller. is there.

  In order to solve the above-described problems, a first aspect of the present invention provides an apparatus main body, a print head provided in the apparatus main body for printing on a recording medium, and a platen for supporting the recording medium printed by the print head. A roller, a drive motor provided in the apparatus main body at a position below the roller surface of the platen roller and facing the roller surface, and the power of the drive motor via the first and second power transmission systems And a power transmission means for transmitting and rotating the both ends of the platen roller.

  According to the present invention, the power transmission means for transmitting power to the platen roller can be balanced on the left and right sides, the conveyance of the recording medium can be stabilized, and good print image quality can be obtained.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a printing apparatus 1 according to an embodiment of the present invention.

  The printing apparatus 1 includes an apparatus main body 1a. The apparatus main body 1a includes a lower casing 2 and an upper casing 3 that is provided in the lower casing 2 so as to be freely opened and closed. A platen roller 5 is provided on the upper side in the lower housing 2, and a drive motor 6 for rotating the platen roller 5 is provided on the lower side. A thermal head 7 as a print head is provided in the upper housing 3.

  Lock levers 9a and 9b as locking members are disposed on both side surfaces of the upper housing 3, and locking pins 10a and 10b as locking portions protrude from both side surfaces of the lower housing 2. Has been. When the upper housing 3 is closed, the thermal head 7 is opposed to the platen roller 5, and the lock levers 9a and 9b are detachably locked to the locking pins 10a and 10b to be locked. Yes.

  FIG. 2 shows a drive motor 6 disposed in the lower housing 2 and a power transmission means 11 for transmitting the power to the platen roller 5.

  The drive motor 6 is provided below the platen roller 5 in the lower housing 2 and at a position facing the roller surface of the platen roller 5. A motor gear 21 is attached to the motor shaft 6a. Platen gears 14 a and 14 b are attached to both ends of the shaft of the platen roller 5.

  One side of the motor gear 21 of the drive motor 6 is connected to the platen gear 14a via the rotation direction conversion gear 17a, and the other side is connected to the platen gear 14b via the rotation direction conversion gear 17b. It is connected to the.

  The first power transmission system 11a is configured by the rotation direction conversion gear 17a and the platen gear 14a, and the second power transmission system 11b is configured by the rotation direction conversion gear 17b and the platen gear 14b. The first and second power transmission systems 11a and 11b are used to transmit the driving force of the driving motor 6 installed at the lower part of the platen roller 5 to the left and right of the platen roller 5 separately in the left and right directions in the axial direction of the platen roller 5. The power transmission means 11 is configured.

  In the configuration described above, the drive motor 6 is rotated and the motor gear 21 is rotated during printing. The rotation of the motor gear 21 causes the rotation direction conversion gears 17a and 17b and the platen gears 14a and 14b to rotate as indicated by arrows, and the platen roller 5 rotates as indicated by arrows. By this rotation, a sheet (not shown) as a recording medium is nipped and conveyed by the platen roller 5 and the thermal head 7 and printed.

  As described above, according to this embodiment, the drive motor 6 is provided in the lower housing 2 below the roller surface of the platen roller 5 at a position facing the roller surface, and the first and second The driving force of the driving motor 6 can be divided substantially equally by the power transmission systems 11a and 11b and transmitted to the platen gears 14a and 14b provided on the left and right sides of the platen roller 5.

  Accordingly, the conveyance of the paper is stabilized, and the thermal head 7 is brought into contact with the platen roller 5 with a uniform contact pressure along the axial direction, so that a good print image quality can be obtained.

  FIG. 3 shows a second embodiment of the present invention.

  Note that the same parts as those shown in the first embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

  In the second embodiment, one side portion side of the motor gear 13 of the drive motor 6 is connected to the platen gear 14a via the connecting gear 16a and the rotation direction changing gear 17a, and the other side portion side. Is connected to the platen gear 14b via the connecting gear 16b and the rotation direction changing gear 17b. By rotation of the motor gear 13 in the direction of the arrow, the coupling gears 16a and 16b, the rotation direction conversion gears 17a and 17b, and the platen gears 14a and 14b are rotated as indicated by the arrows, and the platen roller 5 is rotated as indicated by the arrows. Is done.

  Also in the second embodiment, the same operational effects as those of the first embodiment described above can be obtained. Furthermore, by providing the connection gears 16a and 16b, it is possible to cope with the large-sized printing apparatus 1 in which the platen roller 5 is longer than in the first embodiment.

  FIG. 4 shows a third embodiment of the present invention.

  Note that the same parts as those shown in the first embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

  In the third embodiment, the rotation direction conversion gear 17a is connected from the upper side of the platen gear 14a.

  The rotation of the motor gear 13 causes the coupling gears 16a and 16b and the rotation direction conversion gears 17a and 17b to rotate in the arrow direction, and the platen roller 5 is rotationally driven in the arrow direction via the platen gears 14a and 14b.

  Also in the third embodiment, the same operational effects as those of the second embodiment described above can be obtained.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, you may delete some components from all the components shown by embodiment mentioned above. Furthermore, you may combine the component covering different embodiment suitably.

1 is a perspective view showing a printing apparatus according to an embodiment of the present invention. FIG. 2 is a front view showing a platen roller driving mechanism provided in the printing apparatus of FIG. 1. The front view which shows the drive mechanism of the platen roller which is the 2nd Embodiment of this invention. The front view which shows the drive mechanism of the platen roller which is the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a ... Apparatus main body, 2 ... Lower housing | casing, 3 ... Upper housing | casing, 5 ... Platen roller, 6 ... Drive motor 7 ... Thermal head (printing head), 9a, 9b ... Lock lever (locking member), 10a, 10b ... Locking pins (locking portions), 11a, 11b, first and second power transmission systems, 11, power transmission means, 14a, 14b, 16a, 16b, 17a, 17b, a plurality of gears.

Claims (3)

The device body;
A print head provided in the apparatus body for printing on a recording medium;
A platen roller that supports the recording medium printed by the print head;
A drive motor provided in the apparatus body at a position below the roller surface of the platen roller and facing the roller surface;
And a power transmission means for transmitting the power of the drive motor to both ends of the platen roller via the first and second power transmission systems and rotating the printing motor.   The printing apparatus according to claim 1, wherein the first and second power transmission systems are a gear train including a plurality of gears.   The apparatus main body is provided with a locking portion on both side portions, a lower housing in which the platen roller, the driving motor, and the power transmission means are disposed, and an openable and closable attachment to the lower housing. 3. A lock member that is removably engaged with the engagement portion is disposed on both side surface portions, and an upper housing having the print head is provided therein. The printing apparatus as described.

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