JP4049130B2 - Drive transmission switching mechanism and color printer using the same - Google Patents

Description

  The present invention includes a drive transmission switching mechanism that switches whether or not to transmit the rotation of the paper transport system to the ink ribbon transport system, and controls the transport of the paper and the ink ribbon by controlling the transport of the paper and the ink ribbon. The present invention relates to a color printer that forms a predetermined image on a sheet using a printer.

  Conventionally, color printers that print color images on paper using yellow, magenta, and cyan ink ribbons are generally prevalent. In this type of color printer, a color image to be printed is color-separated, and a yellow image (hereinafter referred to as a Y image), a magenta image (hereinafter referred to as an M image), and a cyan image (hereinafter referred to as a C image). 3) are generated, and these images are overlaid on the paper by various methods and printed to form a color image on the paper (see, for example, Patent Document 1 and Patent Document 2). ).

  Incidentally, in a thermal transfer type color printer that forms such a color image using an ink ribbon, the image is transferred to a sheet for each color from the structure of the ink ribbon. At this time, since the ink ribbon has a structure in which the areas of the respective colors are sequentially connected, it is only necessary to transport the ink ribbon in a predetermined direction. However, since the paper has to perform image formation (transfer) of each of the three colors in the same area, The paper must be reciprocated with respect to the paper transport path. For this reason, in order to carry the paper and the ink ribbon with the driving force of a single motor, the operation of these two conveyance systems is linked or only one (paper conveyance only) is switched. A drive transmission switching mechanism must be provided.

  FIG. 5A is a front view showing a schematic configuration of a conventional drive transmission switching mechanism, and FIG. 5B is a side view thereof. Note that the illustration of the gear of the ink ribbon transport system is omitted.

  A main driving gear 1 that drives a conveyance roller of a sheet conveyance system meshes with an idler gear 2 by teeth formed on respective circumferential surfaces. The main driving gear 1 and the idler gear 2 are rotatably fixed by a support member 3. Specifically, the main drive gear 1 is rotatably fixed to the support substrate 30 by the main drive shaft 31, and the idler gear 2 is rotatably fixed to the support substrate 30 by the sub drive shaft 32. A spring 4 is disposed between the idler gear 2 and the support substrate 30.

In such a structure, when the main driving gear 1 rotates, this rotation is transmitted to the idler gear 2. At this time, since the spring 4 is arranged between the idler gear 2 and the support substrate 30, when the idler gear 2 rotates, the support substrate 30 and the idler gear 2 rotate with respect to the main drive gear 1 by the frictional force of the spring 4. To do. By using this operation, the gear of the ribbon transport system is arranged at a predetermined distance from the main drive gear 1 in a predetermined direction (position where the idler gear 2 can be meshed), so that the idler gear 2 is moved to the ribbon according to the rotation of the main drive gear 1. It moves to a position that meshes with the gear of the transport system, or conversely moves to a position where the idler gear 2 does not mesh with the gear of the ribbon transport system. Using this, the operation of the paper transport system and the ribbon transport system is controlled by one driving force generation source (motor).

JP-A-9-136466 JP 2001-208162 A

  However, in the conventional drive transmission switching mechanism as shown in FIG. 5, the spring 4 is arranged between the idler gear 2 and the support substrate 30 in order to rotate the idler gear 2 with respect to the main driving gear 1. In order to generate a predetermined frictional force by the spring 4, a structure is employed in which the spring 4 is pushed in the axial direction with a predetermined pressure. In this case, in order to fix the idler gear 2 while pushing it toward the support substrate 30, the auxiliary driving shaft 32 is formed with a pin or the like, and this pin is press-fitted into a recess provided in the support substrate 30 and fixed. In this structure, since pins are used, the number of parts increases, and the number of manufacturing steps increases accordingly, resulting in an increase in cost.

  Accordingly, an object of the present invention is to configure a drive transmission switching mechanism that can be easily manufactured with a reduced number of parts, and a color printer using the drive transmission switching mechanism.

The present invention, driving force from the driving source is transmitted, a first gear you transmit the driving force to the first conveying means for conveying the first medium,
A second gear disposed at a position away from the first gear by a predetermined distance and transmitting a driving force to a second transport means for transporting the second medium;
An idling gear meshing with the first gear;
A support for supporting the idling gear and the first gear;
A spring that is installed between the support and the idling gear, and generates a moving torque of the idling gear by the rotation of the first gear;
A drive transmission switching mechanism for switching the meshing with the second gear by moving the idling gear by the rotation of the first gear;
The support is integrally formed with a shaft support member that supports the idling gear, and a base material that regulates a distance between the first gear, the idling gear, and the shaft,
In addition, the first gear is attached to a position that sandwiches the idling gear with the spring and fixes an axial position of the idling gear .

In this configuration, the first gear meshes with the idling gear, the first gear pushes the idling gear toward the base material with a predetermined pressure, and the spring pushes the idling gear against the base material with a predetermined pressure. Fix in a rotatable manner. Thereby, the member which pushes an idling gear toward a base material and fixes it rotatably is abbreviate | omitted.
Further, the surface on the base material side of the first gear is in contact with a surface on the opposite side to the surface on the base material side of the idling gear .

In this configuration, teeth are formed on the driving force transmission portion of the first gear , that is, the circumferential surface, and the base-side surface of the disc portion meshing with the idling gear is opposite to the base- side surface of the idling gear. The disk portion of the first gear functions as a driving force transmission portion to the idling gear and functions as a member that pushes the idling gear with a predetermined pressure toward the base material.

The present invention also provides color separation means for color-separating a color image to be printed to generate three images, a yellow image, a magenta image, and a cyan image,
Paper transport means for reciprocating the paper along the paper transport path;
Thermal transfer means for thermally transferring an ink ribbon in which yellow, magenta, and cyan areas appear in sequence to the paper according to the three-color images of the yellow image, magenta image, and cyan image generated by the color separation means;
Ribbon transport means for transporting the ink ribbon in a predetermined direction;
In a color printer comprising: a drive transmission switching mechanism that switches whether or not the driving force transmitted to the paper transport unit is transported to the ribbon transport unit;
The drive transmission switching mechanism is
A first gear that transmits the driving force to the sheet conveying means when the driving force is transmitted;
A second gear disposed at a predetermined distance from the first gear and transmitting the driving force to the ribbon conveying means;
An idling gear that meshes with the first gear and switches the meshing with the second gear by moving by the rotation of the first gear;
An idling gear shaft supporting member that pivotally supports the idling gear, the first gear, the idling gear, and a base material that regulates an inter-axis distance are integrally formed to support the idling gear and the first gear. A supporting body,
Is installed between the idle gear and the support, together with and a spring for generating a movement torque of the idling gear by rotation of said first gear,
The first gear is attached to a position that sandwiches the idling gear with the spring and fixes the axial position of the idling gear; and
The base-side surface of the first gear is in contact with a surface opposite to the base-side surface of the idling gear .

In this configuration, the drive transmission switching mechanism described above is applied to a color printer, the first gear is used for driving force transmission of the paper conveying means, and the second gear is used for driving force transmission means of the ribbon conveying means. Then, the idling gear by rotating and rotated by the first gear, engagement of the idle gear and the second gear is controlled. Thus, control is performed to synchronize / asynchronize the operation of the ribbon conveying means with respect to the operation of the paper conveying means. As a result, whether to carry the ribbon is switched according to the paper carrying direction. At this time, the first gear transmits the driving force to the idling gear and pushes the idling gear in the base material direction with a predetermined pressure to rotate and rotate the idling gear.

According to the invention, the transmitting the driving force of the idling gear with the first gear, the idling gear can be rotatably fixed relative to the first gear, a simple structure, and manufacturing is easy driving A transmission switching mechanism can be configured.

In addition, according to the present invention, since the idling gear is pushed by the driving force transmission portion of the first gear, a drive transmission switching mechanism having a simpler structure can be configured.

  Further, according to the present invention, by using this drive transmission switching mechanism, the reciprocating conveyance of the paper and the constant direction conveyance of the ink ribbon can be operated by one motor, so that the structure is simple and the production is possible. An easy color printer can be configured.

A drive transmission switching mechanism according to a first embodiment of the present invention will be described with reference to the drawings. In the following description, a drive transmission switching mechanism used for the paper conveyance unit and the ink ribbon conveyance unit of the color printer will be described.
Fig.1 (a) is a front view which shows schematic structure of the drive transmission switching mechanism based on this embodiment, FIG.1 (b) is the side view.

As shown in FIG. 1, the drive transmission switching mechanism meshes with a main drive gear 1 attached to a paper transfer roller (not shown) of a paper transfer unit corresponding to the transfer unit of the present invention, and the main drive gear 1 . provided with idler gear 2, a driven gear 5 disposed in a predetermined distance away from the main movement gears 1. Next center distance from the main movement gears 1 and idler gear 2 is fixed, and is supported by a support member 3 which rotatably fixed around the shaft center of the drive gear 1 an idler gear 2 in the circumferential direction of the main drive gear 1 ing. The support member 3 includes a main drive shaft 31 that pivotally supports the main drive gear 1 with respect to the support substrate 30 through a through-hole having a predetermined diameter formed at the shaft center of the main drive gear 1, and an axis center of the idler gear 2. And a secondary driving shaft 32 that is inserted through a through-hole of a predetermined diameter and rotatably supports the idler gear 21 with respect to the support substrate 30, and is perpendicular to the axial direction of the main driving shaft 31 and the secondary driving shaft 32. It comprises a support substrate 30 whose surface is the main surface. The support member 3 including the support substrate 30, the main drive shaft 31, and the sub drive shaft 32 is integrally formed of a resin material or the like. Further, the support member 3 is installed so as to be rotatable about the axis of the main drive shaft 31 with respect to the printer housing and the main drive gear 1 (not shown ).
The driven gear 5 is pivotally supported with respect to the printer housing by a driven shaft 51 inserted through a through-hole having a predetermined diameter formed at the center of the driven gear 5. The driven gear 5 is connected to a gear (illustrated) provided on the shaft of the ink ribbon cartridge corresponding to the ribbon transport means of the present invention.

The main driving gear 1 includes a base portion 11 on which a tooth is not formed on a circumferential surface and a driving force transmission portion 12 having a diameter larger than that of the base portion 11 and teeth formed on the circumferential surface. It is installed on the support substrate 30 side.
The idler gear 2 includes a base portion 21 in which teeth are not formed on the circumferential surface and a driving force transmission portion 22 having a diameter smaller than that of the base portion 21 and teeth formed on the circumferential surface, and the base portion 21 supports the idler gear 2. It is installed so as to be on the substrate 30 side.
Then, the teeth formed on the circumferential surface of the driving force transmission unit 12 of the main driving gear 1 and the teeth formed on the circumferential surface of the driving force transmission unit 22 of the idler gear 2 mesh with each other, so that the main driving gear 1 is engaged. The transmitted driving force is transmitted to the idler gear 2.

Further, the surface opposite to the surface facing the support substrate 30 of the base portion 21 of the idler gear 2 (the surface on the driving force transmission portion 22 side) is the surface facing the support substrate 30 of the driving force transmission portion 12 of the main gear 1 ( The surface of the base 11 side). Additionally, idler gear 2 and scan pulling 4 is installed between the supporting substrate 30, by the driving force transmitting portion 12 of the main moving gear 1 in the spring 4 abuts against the base portion 21 of the idler gear 2, a predetermined The pressure is applied.

  With this configuration, the idler gear 2 is sandwiched between the driving force transmission portion 12 of the main driving gear 1 and the spring 4 and is fixed at a predetermined position in the axial direction of the sub driving shaft 32.

Next, the operation of the drive transmission switching mechanism having such a configuration will be described with reference to FIGS.
2 and 3 are schematic side views showing the operating state of the drive transmission switching mechanism. FIG. 2 shows a case where the main gear 1 rotates in the forward direction (direction in which the paper is transported from the paper supply side to the paper carry-out side). FIG. 3 shows a case where the main gear 1 rotates in the reverse direction (direction in which the paper is conveyed from the paper carry-out side to the paper supply side). 2A shows a state in which the idler gear 2 approaches the driven gear 5, and FIG. 2B shows a state in which the idler gear 2 is engaged with the driven gear 5. FIG. 3A shows a state where the idler gear 2 is engaged with the driven gear 5, and FIG. 3B shows a state where the idler gear 2 is separated from the driven gear 5.

  First, when a driving force is transmitted to the main driving gear 1 from a motor (not shown), the main driving gear 1 rotates in the forward direction. When the main driving gear 1 rotates in the forward direction, a sheet conveying roller (not shown) attached coaxially with the main driving gear 1 rotates in the forward direction.

  When the main driving gear 1 rotates in the forward direction, the idler gear 2 meshing with the main driving gear 1 rotates and the driving force is transmitted. Here, the idler gear 2 is held between the main driving gear 1 and the spring 4, and the spring 4 applies a predetermined urging force (pressing force) to the idler gear 2 and the support substrate 30, so that the idler gear 2 rotates. The idler gear 2 and the support substrate 30 rotate about the axis of the main driving gear 1 as a rotation center. When the idler gear 2 comes into contact with the driven gear 5 and the teeth of the idler gear 2 mesh with the teeth of the driven gear 5, the rotation of the idler gear 2 is stopped and the rotation of the idler gear 2 is transmitted to the driven gear 5. The driven gear 5 rotates in the ribbon conveyance forward direction (direction in which the ink ribbon is conveyed from the supply side to the take-up side).

  For example, as shown in FIG. 2, when the main driving gear 1 rotates clockwise (forward direction) when viewed from the support substrate 30 side, the idler gear 2 rotates counterclockwise and rotates clockwise. (FIG. 2 (a)). And if the idler gear 2 meshes with the driven gear 5, the driven gear 5 will rotate clockwise (FIG.2 (b)). Since the driven gear 5 is engaged with the shaft of the ink ribbon cartridge, this rotation causes the shaft of the ink ribbon cartridge to rotate counterclockwise. As the ink ribbon cartridge shaft rotates counterclockwise, the ink ribbon is transported in the ribbon transport forward direction. That is, the ink ribbon can be transported in the ribbon transport forward direction in synchronization with transport of the paper in the forward direction (from the paper supply side to the paper carry-out side).

  On the other hand, when a driving force opposite to that described above is transmitted to the main driving gear 1 from a motor (not shown), the main driving gear 1 rotates in the direction opposite to the above. When the main driving gear 1 rotates in the reverse direction, a paper transport roller (not shown) attached coaxially with the main driving gear 1 rotates in the reverse direction (the direction in which the paper is transported from the paper carry-out side to the paper supply side). .

By drive gear 1 rotates in the opposite direction, idler gear 2 meshed with the drive gear 1 is the driving force to rotate is transmitted. Here, the idler gear 2 is held between the main driving gear 1 and the spring 4, and the spring 4 applies a predetermined urging force (pressing force) to the idler gear 2 and the support substrate 30, so that the idler gear 2 rotates. The idler gear 2 and the support substrate 30 rotate in the direction opposite to the above with the axis of the main driving gear 1 as the rotation center. Thus, when the idler gear 2 rotates in the reverse direction, the idler gear 2 is separated from the driven gear 5 and the rotation of the driven gear 5 stops. The idler gear 2 stops when it rotates to a predetermined position with respect to the main driving gear 1, and continues to rotate at this stop position.

  For example, as shown in FIG. 3, when the main driving gear 1 rotates counterclockwise (reverse direction) when viewed from the support substrate 30 side, the idler gear 2 rotates clockwise and rotates counterclockwise. (FIG. 3 (a)). When the idler gear 2 rotates and moves away from the driven gear 5, the rotation of the driven gear 5 stops, and the idler gear 2 rotates counterclockwise while rotating clockwise about the axis center of the main driving gear 1 as the rotation center. (FIG. 3B). With such a configuration, the ink ribbon is not conveyed when the sheet is conveyed in the reverse direction (from the sheet carry-out side to the sheet supply side).

  With the above configuration, the ink ribbon can be transported when the paper is transported in the forward direction, and the transport of the ink ribbon can be stopped when the paper is transported in the reverse direction. That is, it is possible to configure a drive transmission switching mechanism that performs switching control of two drives with one motor. By using the above-described configuration, the position of the idler gear in the axial direction can be fixed by the main gear, so that the drive transmission switching mechanism can be configured with a simple structure, and the manufacturing process is further simplified. A drive transmission switching mechanism can be easily formed.

  Next, a color printer according to the second embodiment will be described.

FIG. 4 is a block diagram showing the configuration of the main part of the color printer according to the embodiment of the present invention.
The color printer 100 according to this embodiment includes a control unit 101 for the operation of the main body, an image input unit 102 for receiving an input of a color image to be printed, and a color image input to the image input unit 102 for color separation to obtain a yellow image. (Hereinafter referred to as “Y image”), magenta image (hereinafter referred to as “M image”), and cyan image (hereinafter referred to as “C image”). A conveyance unit 104 that conveys the image, and a printing unit 105 that prints the Y image, the M image, and the C image on the paper that is conveyed by the conveyance unit 104 are provided. Here, the printing unit 105 corresponds to a ribbon transport unit and a thermal transfer unit of the present invention.

  The image input unit 102 receives a captured image captured by a digital camera and a read image read by a scanner or the like. The input image processing unit 103 performs color separation on the input image to generate a Y image, an M image, and a C image. The printing unit 105 prints a color image on paper using an ink ribbon. This ink ribbon is obtained by repeatedly forming yellow, magenta, cyan, and overcoat ink layers for each length in the paper transport direction. The printing unit 105 prints the Y image on the paper, prints the M image on the printed Y image, then prints the C image on the printed Y image and the M image, and finally prints the entire image on the paper. Overcoat is applied to complete the printing of the color image. As described above, since the printing unit 105 is configured to print the Y image, the M image, and the C image in separate printing processes, the conveyance unit 104 is configured to be able to reciprocate the sheet on the sheet conveyance path. On the other hand, the ink ribbon transport unit of the printing unit 105 is configured to transport the ink ribbon only in a certain direction because the ink ribbon has a structure in which the ink layers are sequentially connected as described above. The transport unit 104 and the ink ribbon transport unit are driven by a single motor. Here, by using the above-described drive transmission switching mechanism in this drive system, the above-described conveyance of the paper and the conveyance of the ink ribbon can be realized with a simple structure. That is, a color printer having a simple structure can be configured.

  In the above description, the configuration in which the drive transmission switching mechanism is applied to a color printer has been described. However, the present invention is not limited to a color printer, and is an apparatus having a structure in which two drive systems are driven synchronously and asynchronously with a single drive source. If so, the above-described drive transmission switching mechanism can be applied, and the above-described effects can be obtained.

The front view and side view which show schematic structure of the drive transmission switching mechanism which concerns on 1st Embodiment Schematic side view showing an operation state when the main driving gear 1 of the drive transmission switching mechanism rotates clockwise. Schematic side view showing an operation state when the main gear 1 of the drive transmission switching mechanism rotates counterclockwise. FIG. 3 is a block diagram illustrating a configuration of a main part of a color printer according to a second embodiment. Front view and side view showing a schematic configuration of a conventional drive transmission switching mechanism

Explanation of symbols

1-main driving gear 11-base 12 of main driving gear 1-driving force transmission unit of main driving gear 1-idler gear 21-base 22 of idler gear 2-driving force transmission unit of idler gear 2 3-support member 30-support substrate 31-main driving Axis 32-secondary driving shaft 4-spring 5-driven gear 51-driven shaft 100-color printer 101-control unit 102-image input unit 103-input image processing unit 104-transport unit 105-printing unit

Claims (3)

Color separation means for color-separating a color image to be printed to generate three images of a yellow image, a magenta image, and a cyan image;
Paper transport means for reciprocating the paper along the paper transport path;
Thermal transfer means for thermally transferring an ink ribbon in which yellow, magenta, and cyan areas appear in sequence to the paper according to the three-color images of the yellow image, magenta image, and cyan image generated by the color separation means;
Ribbon transport means for transporting the ink ribbon in a predetermined direction;
In a color printer comprising: a drive transmission switching mechanism that switches whether or not the driving force transmitted to the paper transport unit is transported to the ribbon transport unit;
The drive transmission switching mechanism is
A first gear that transmits the driving force to the sheet conveying means when the driving force is transmitted;
A second gear disposed at a predetermined distance from the first gear and transmitting the driving force to the ribbon conveying means;
An idling gear that meshes with the first gear and switches the meshing with the second gear by moving by the rotation of the first gear;
An idling gear shaft supporting member that pivotally supports the idling gear, the first gear, the idling gear, and a base material that regulates an inter-axis distance are integrally formed to support the idling gear and the first gear. A supporting body,
Is installed between the idle gear and the support, together with and a spring for generating a movement torque of the idling gear by rotation of said first gear,
The first gear is attached to a position that sandwiches the idling gear with the spring and fixes the axial position of the idling gear; and
The surface of the first gear on the substrate side is in contact with the surface of the idling gear opposite to the surface on the substrate side . Driving force from the driving source is transmitted, a first gear you transmit the driving force to the first conveying means for conveying the first medium,
A second gear disposed at a position away from the first gear by a predetermined distance and transmitting a driving force to a second transport means for transporting the second medium;
An idling gear meshing with the first gear;
A support for supporting the idling gear and the first gear;
A spring that is installed between the support and the idling gear, and generates a moving torque of the idling gear by the rotation of the first gear;
A drive transmission switching mechanism for switching the meshing with the second gear by moving the idling gear by the rotation of the first gear;
The support is integrally formed with a shaft support member that supports the idling gear, and a base material that regulates a distance between the first gear, the idling gear, and the shaft,
The drive transmission switching mechanism is characterized in that the first gear is attached to a position that sandwiches the idling gear with the spring and fixes an axial position of the idling gear . The drive transmission switching mechanism according to claim 2 , wherein a surface of the first gear on the substrate side is in contact with a surface of the idling gear opposite to the surface on the substrate side .

Images