JP2000247005A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply helpingly the constitution of a monochrome printer almost as it is to a multicolor printer, and optionally set the rotating speed of a cam. SOLUTION: A printer is provided with a frame 1 with an ink ribbon cassette 30 and a cassette lifting and lowering unit provided removaly on the side of the frame 1 and lifting and lowering the ink ribbon cassette 30. The cassette lifting and lowering unit is provided with a gear mechanism 6 transmitting the rotation of a drive shaft provided on the frame 1 to brackets 4 and 5 set removably on a frame 1, a cam mechanism 9 lifting and lowering the ink ribbon cassette 40, a clutch mechanism 7 selectively transmitting the rotation of the gear mechanism 6 to the cam mechanism 9 and an actuator 8 for cutting/ connecting the clutch mechanism 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer capable of changing a printing color by moving an ink ribbon in a width direction thereof, and more particularly, to easily changing a printer of a single color printing to a printer of a two-color printing, for example. To a versatile printer that can.

[0002]

2. Description of the Related Art In a printer for two-color printing, a printing color is changed by moving an ink ribbon having a different color in the width direction in the width direction. For example, Japanese Patent No. 560881
Japanese Patent Application Laid-Open No. H11-115,811 discloses a configuration in which a cam is driven by a motor to tilt a cassette support portion that supports an ink ribbon cassette. However, this printer requires a dedicated motor for tilting the ink ribbon cassette, and thus has a problem that the manufacturing cost is high. Therefore, in Japanese Patent Application Laid-Open No. H10-157261, an input shaft of a one-way clutch is attached to a drive shaft for moving a print head, a cam is attached to an output shaft of the one-way clutch, and the one-way clutch is disconnected and connected by a solenoid at any time. The cam is rotated so that the cassette supporting portion engaged with the cam is tilted up and down.

[0003]

The printers according to the above proposals are all dedicated to two-color printing.
There is a problem that the compatibility of parts with a printer for monochromatic printing is low, and the manufacturing cost is relatively high. Also, Japanese Patent Application Laid-Open
In the technique disclosed in Japanese Patent Application Laid-Open No. 0-157261, the rotation of the drive shaft is directly transmitted to the cam through the one-way clutch. Therefore, the present invention has been made in order to solve the above-mentioned disadvantages of the prior art, and it is possible to use the configuration of a printer for monochromatic printing almost as it is, and of course to reduce the manufacturing cost. It is an object of the present invention to provide a printer capable of arbitrarily setting the rotation speed of a cam.

[0004]

SUMMARY OF THE INVENTION A printer according to the present invention comprises a printer main body having an ink ribbon cassette, and a cassette elevating unit which is detachably provided on a side portion of the printer main body to raise and lower the ink ribbon cassette. The elevating unit includes a gear mechanism for transmitting rotation of a print head drive shaft provided on the printer body to a bracket detachably attached to the printer body, a cam mechanism for elevating the ink ribbon cassette, and rotation of the gear mechanism. And a drive mechanism for selectively connecting and disconnecting the clutch mechanism.

In the printer having the above-described structure, the rotation of the drive shaft is transmitted to the cam mechanism via the gear mechanism and the clutch mechanism, and the drive mechanism disconnects and connects the clutch mechanism, thereby raising and lowering the ink ribbon cassette when necessary. Then, the printing color can be changed. And since such a configuration is provided in the cassette elevating unit, it is possible to configure a printer for two-color printing or multi-color printing simply by attaching the cassette elevating unit based on a printer for single-color printing, All components of the basic configuration can be made common. Further, by selecting the gear ratio by the gear mechanism, the rotation speed of the cam mechanism can be set arbitrarily.

Here, the printer main body has a cassette support for supporting the ink ribbon cassette such that the base end portion is rotatably supported by the printer main body so that the front end portion on the ink ribbon side can tilt up and down. It is desirable to have a part. The bracket includes a first bracket detachably attached to a side portion of the printer body, one end of which is connected to the first bracket so as to be movable in a predetermined range in a vertical direction, and is moved up and down by a cam mechanism. The second part is detachably attached to the cassette supporting part.
It is desirable to have a bracket. The first bracket supports the gear mechanism, the cam mechanism, the clutch mechanism, and the drive mechanism, so that the attachment of the cassette elevating unit to the printer main body is greatly simplified, and the printer can perform two-color printing or multi-color printing. Can be easily changed.

The drive shaft preferably has a rotation transmitting shaft that protrudes from the side of the printer body and rotates by rotation of the drive shaft. As this rotation transmission shaft, a shaft in which the support shaft of the drive shaft is directly projected from the printer main body may be used, or another shaft connected to the support shaft via a gear train may be used. In addition, the gear mechanism includes a front gear that meshes with a gear provided on the rotation transmission shaft, and a rear gear connected to the front gear via a clutch mechanism, thereby facilitating connection between the drive shaft and the gear mechanism. Can be done. further,
The cam mechanism is preferably provided with a cam that is provided in the rear gear and vertically engages with the second bracket to move the second bracket in the vertical direction with the rotation of the rear gear. Thereby, the movement of the second bracket is restrained by the cam, and a reliable operation is performed.

Here, the clutch mechanism may have a structure in which an input gear, a trigger ring, and an output gear are coaxially rotatably fitted to each other. Specifically, a clutch spring is provided on a clutch cylinder provided at the center of the input gear, and one end of the clutch spring is engaged with a trigger ring fitted on the inner periphery of the input gear. Also, the clutch spring is passed through the trigger ring, and the other end is engaged with the output gear. If the rotation direction of the input gear is set as the tightening direction of the clutch spring, the trigger ring and the output gear engaged with the clutch spring rotate together with the rotation of the input gear. Also, when the trigger ring is stopped by a trigger such as a protrusion provided on the outer periphery of the trigger ring, the trigger ring and the output gear rotate relatively in the direction in which the clutch spring is loosened. It becomes free and only the input gear rotates.

By providing the triggers of the clutch mechanism at a plurality of positions in the circumferential direction and devising the shape of the cam controlled by the clutch mechanism, the stop position of the cassette support can be set in small increments. Thereby, it is possible to correspond to a multicolor ink ribbon. Since the drive shaft is also rotating when the cassette support is tilted, the print head is moved to the print position after stopping the tilt of the cassette support. The cam mechanism can be provided on the output gear of the clutch mechanism.

It is preferable that a paper feeding motor and a drive mechanism for rotating a drive shaft are arranged on the side of the printer body opposite to the cassette elevating unit, since a space for the cassette elevating unit is ensured. Further, the first bracket and the printer main body may be positioned by providing a hole in a side portion of the printer main body to be fitted with at least one of the gear shafts of the gear mechanism. Further, by providing a hook at the front end or the rear end of the first bracket for engaging with a hole provided in the printer main body, the first bracket can be screwed to the printer main body by one.
Can be done in places.

[0011]

DETAILED DESCRIPTION OF THE INVENTION A. Configuration of embodiment A-1. The basic structure of the printer and then referring to FIGS described embodiments of the present invention. FIG. 1 is a plan view showing a printer, and FIGS. 2 and 3 are side views thereof. 1 to 3 show a state in which the cassette elevating unit is not attached. In addition, when the direction is indicated in the following description, the upper side of FIG. 1 is the front (front) side, the lower side is the rear side, and the left-right direction is the direction as shown in FIG. In the figure, reference numeral 1 denotes a frame (printer main body). The frame 1 is roughly composed of a bottom plate 1a and side plates 1b rising upward from both sides of the bottom plate 1a. The side plate portion 1b has a substantially U-shape in side view, and the drive shaft 2 is rotatably supported by a drive shaft (rotation transmission shaft) 20 on each side plate portion 1b. Inside the right side plate portion 1b of the frame 1, D
A C motor (not shown) is attached, and its rotation is transmitted to the drive shaft 2 via gears 21, 22 and the like.

As shown in FIG. 1, a shaft 23 is provided on the side plates 1b, 1b, and a carriage 24 is supported on the shaft 23 so as to be slidable in the axial direction. The carriage 24 is engaged with a groove 2 a provided on the outer periphery of the drive shaft 2, and travels in the axial direction as the drive shaft 2 rotates. A print head 25 is mounted on the carriage 24, and a platen 2 laid on the side plate portions 1 b, 1 b is provided.
6 is printed on paper.

In the drawings, reference numeral 3 denotes a cassette support. Arms 31 and 32 that support the front and rear of the ink ribbon cassette 30 are arranged on the front and rear edges of the cassette support 3. A projecting piece 33 projecting to the left in FIG. on the other hand,
Arms 11 extending upward are disposed on both sides of the rear end of the side plate portion 1b, and a drum-shaped hole 12 is formed at the upper end of the arm 11 (see FIG. 2). When the projecting piece 33 is inserted into the hole 12, the front end of the cassette supporting portion 3 can be vertically tilted about the projecting piece 33 by a predetermined angle. Further, as shown in FIGS. 2 and 3, the rear end of the cassette support 3
A stopper 34 extending downward is arranged. On the other hand, the arm 13 that overlaps the stopper 34 in the front-rear direction is disposed on the bottom plate 1 a of the frame 1, and the arm 13 and the stopper 34 are attached to each other by the screw 14.
As a result, the position of the cassette support 3 is fixed.

The cassette support 3 constructed as described above
Supports an ink ribbon cassette 30. Arms 30a extending forward are formed at both left and right ends of the ink ribbon cassette 30, and the ink ribbon 30b pulled out from the tip of one arm 30a is connected to the print head 2a.
5 and the platen 26, and is inserted into the other arm 30a. The ink ribbon 30 b is wound endlessly in the ink ribbon cassette 30, and is rotated in conjunction with the rotation of the drive shaft 2.
0c is sent continuously.

In FIG. 1, reference numeral 35 denotes a paper feed roller unit. The paper feed roller in the paper feed roller unit is rotated by a stepping motor 36 and a gear train 37 so that the paper inserted from a paper feed port 38 is connected to the print head 25. The platen 26 is supplied.

A-2. The above configuration of the cassette elevating unit is the basic configuration of the printer when the monochromatic ink ribbon 30b is used. Next, the configuration of the cassette elevating unit will be described with reference to FIGS. In these figures, reference numeral 4 is a first bracket, and reference numeral 5 is a second bracket. A gear mechanism 6 is provided on the first bracket 4
0, 41, the clutch mechanism 7 is attached by the shaft 42, and the actuator (drive mechanism) 8 is
Attached by one. The gear mechanism 6 is provided with a cam mechanism 9. In FIG. 5, reference numeral 44 denotes a hole for screwing the first bracket 4 to the frame 1. Hereinafter, the configurations of the gear mechanism 6 to the cam mechanism 9 will be described.

(1) Gear Mechanism In the figure, reference numeral 60 denotes a first gear in which a large-diameter gear (previous-stage gear) 61 and a small-diameter gear 62 are integrally formed. It is supported rotatably. The large-diameter gear 61 meshes with the gear attached to the drive shaft 20 in a state where the first bracket 4 is attached to the frame 1. Also,
The small-diameter gear 62 meshes with a second gear 63 rotatably supported on the first bracket 4 by the shaft 41. A third gear (later stage gear) 64 is rotatably supported on the shaft 41.

(2) Clutch mechanism As shown in FIG. 4, an input gear 70 meshing with the second gear 63 is rotatably supported on the shaft 42. A clutch cylinder 71 projecting in the axial direction (right side in FIG. 4) is formed at the center of the input gear 70, and the inner circumference of the clutch cylinder 71 is slightly larger than the inner diameter of the clutch cylinder 71 in a no-load state. Is provided. A trigger ring 73 is provided on an inner peripheral portion of the input gear 70.
Are fitted. One end of a clutch spring 72 is engaged with the trigger ring 73. As shown in FIG. 5, a trigger 74 including a trapezoidal projection is formed on an outer peripheral portion of the trigger ring 73. Triggering 7
An output gear 75 is rotatably supported by the shaft 42 on the outer side of 3. The other end of the clutch spring 72 is engaged with the inner end surface of the output gear 75. The output gear 75 meshes with the third gear 64 of the gear mechanism 6. Reference numeral 76 in the figure denotes an E-ring for preventing the output gear 75 from coming off.

The rotation direction of the input gear 70 is the tightening direction of the clutch spring 72. Therefore, when the input gear 70 rotates, the clutch spring 72 is tightened to tighten the clutch cylinder 71, and the trigger ring 73 and the output gear 75 engaged with the clutch spring 72 rotate together.
When the actuator 8 described below is brought into contact with the trigger 74 and stopped, the trigger ring 73 and the output gear 75 relatively rotate in the direction in which the clutch spring 72 is loosened. 71 is released from the clutch spring 72 and only the input gear 70 rotates.
Therefore, the rotation is not transmitted to the output gear 75.

(3) Actuator In the figure, reference numeral 80 denotes a solenoid,
1 and a screw 82 to the first bracket 4. An iron core 83 formed integrally with the bracket 81 is inserted into the upper end of the solenoid 80, and the iron core 83 penetrates the solenoid 80 and protrudes from the lower end. On the opposite side of the iron core 83, a hook 84 protruding forward is formed. Further, an arm 85 extending downward is formed at an intermediate portion between the iron core 83 and the hook 84. At the lower end of the arm 85, an intermediate portion of a trigger arm 86 extending in the front-rear direction is supported so as to be vertically tiltable. Trigger arm 8
The front end of 6 is urged upward by a tension coil spring 87 provided on the trigger arm 86 and the hook 84. As a result, the trigger arm 86 is connected to the solenoid 8
In a state in which 0 is not excited, the trigger 7
4, the clutch mechanism 7 is disconnected. The rear end of the trigger arm 86 is attracted to the iron core 83 by exciting the solenoid 80, thereby releasing the trigger 74 and connecting the clutch mechanism 7.

(4) Cam Mechanism On the end face of the third gear 64 of the gear mechanism 6, a cam 90 having a circular shape in a side view and having a center eccentric with respect to the shaft 41 is provided.
And are formed integrally with it. On the other hand, the second bracket 5
Is composed of a mounting portion 50 that faces in a substantially horizontal direction and a driving portion 51 that extends perpendicularly to the mounting portion 50 and extends downward. The driving portion 51 holds the cam 90 from above and below. An arranged plate 91 is formed. An elongated hole 92 is formed in an intermediate portion between the plates 91 so as to be inclined upward and rearward.
Is penetrating. With this configuration, when the third gear 64 rotates, the cam 90 rotates, and the plate 91 is pressed by the cam 90 so that the second bracket 5 moves along the elongated hole 92.

A-3. Mounting structure of the cassette lifting unit Next, the configuration for attaching the cassette lifting unit having the above structure is detachably on the frame 1. First, a screw hole or a hole (not shown) is formed in the end of the drive shaft 20 of the drive shaft 2 so that the gear is fitted to the drive shaft 20 and then the screw is stopped by a screw or a pin. . The mounting portion 50 of the second bracket 5 includes
A screw hole 52 and a projection 53 are formed, and holes 35 and 36 are formed in the cassette supporting portion 3 corresponding to the screw hole 52 (see FIG. 1). Further, the shaft 4 supported by the first bracket 4
The ends of 0, 41, and 42 are slightly protruded from the back surface of the first bracket 4, and projections 45 (see FIG. 5) are also formed on the back surface of the first bracket 4. The side plates 1b of the frame 1 are formed with holes 15, 16, 17, 18 to be fitted therein. Further, a hook 46 (see FIG. 4) protruding laterally is formed on the back surface side of the first bracket 4, and a long hole 19 is formed in the side plate portion 1b of the frame 1 correspondingly. . Also, corresponding to the hole 44 of the first bracket 4, the side plate portion 1b
Is formed with a screw hole 19a.

B. Operation of Embodiment B-1. Single Color Printing Operation Next, the operation of the embodiment having the above configuration will be described first, starting with the operation of single color printing. When the paper is inserted into the paper feed port 38 of the paper feed roller unit 35, the internal paper feed roller rotates to feed the paper to the print head 25 and the platen 26.
Supply between and stop. Next, the drive shaft 2 rotates and the print head 25 performs printing while traveling. At this time, the ribbon feeder 30c rotates to feed the ink ribbon 30b. When the printing of the first line is completed, the paper feed roller unit 35 feeds the paper by one line, and the print head 2
5 prints the next line. When the printing of all the rows is completed, the paper feed roller unit 35 discharges the paper.

B-2. It mounted next cassette lifting mechanism, for explaining the procedure for changing the printer for single color printing in the printer for two-color printing. First, as shown in FIG. 7, the gear 27 is fitted to the drive shaft 20, is prevented from rotating by a screw or a pin, and is prevented from coming off by an E-ring 28. In addition, the screw 14 holding the stopper 34 is removed, and the cassette supporting unit 3 is set in a state where it can be tilted. Next, the hook 46 of the first bracket 4 is hooked on the long hole 19 of the side plate 1b, and the first bracket 4 is brought into close contact with the side plate 1b. At this time, the shafts 40 to 42 and the projections 45 are fitted into the holes 15 to 18 of the side plate portion 1b. Thereby, the first
The large-diameter gear 61 of the gear 60 meshes with the gear 27 of the drive shaft 20. Then, a screw 47 is passed through the hole 44 to form the screw hole 19a.
(See FIG. 7). Next, the mounting portion 50 of the second bracket 5 is overlaid on the lower surface of the cassette supporting portion 3, and the projection 53 is fitted into the hole 36. Next, a screw 54 is passed through the hole 35 and fastened to the screw hole 52. From the above,
The two-color printing printer shown in FIGS. 6 and 7 is configured.

B-3. Two-Color Printing Operation Next, an operation of performing two-color printing by the printer having the cassette elevating unit mounted as described above will be described. In this case, the upper half of the ink ribbon 30b in the width direction is a basic color (for example, black), and the lower half is another color (for example, red). In a state where the basic color is printed, the cassette supporting portion 3 is positioned horizontally, and the print head 25 faces the basic color of the ink ribbon. In the state shown in FIG. 5, since the trigger arm 86 is in contact with the trigger 74, the connection of the clutch mechanism 7 is disconnected. Therefore, the drive shaft 20
Of the gear 27 is controlled by the gear mechanism 6 and the clutch mechanism 7.
, But the rotation is not transmitted beyond that. Therefore, the cassette support 3 is kept horizontal, and printing of the basic color is continued.

Here, when the solenoid 80 is excited,
The rear end of the trigger arm 86 is pulled toward the solenoid 80, and the front end of the trigger arm 86 is separated from the trigger 74. Thereby, the clutch mechanism 7 is connected, and the trigger ring 73 and the output gear 75 rotate together with the input gear 70. Accordingly, the third gear 64 of the gear mechanism 6 rotates, and the cam 90 rotates to push up the plate 91 of the second bracket 5. Then, the second bracket 5 rises along the elongated hole 92, and the cassette support portion 3
3 is tilted upwards. That is, the ink ribbon cassette 30 tilts upward.

Next, when the excitation of the solenoid 80 is stopped, the trigger arm 86 is tilted by the elastic force of the extension coil spring 87 and comes into contact with the outer peripheral surface of the trigger ring 73.
Thereafter, the trigger 74 makes one round and comes into contact with the trigger arm 86, and the connection of the clutch mechanism 7 is disconnected. As a result, the rotation of the cam 90 is stopped. At this time, the cam 90 has been rotated by 180 degrees, and the cassette support 3 is at the most inclined position. Then, the lower half (red) of the ink ribbon faces the print head 25, and in this state, the print head 25 is moved to the next print position to perform printing.
When the print color is returned to the basic color, the solenoid 80
To rotate the cam 90 by 180 degrees to make the cassette support 3 horizontal.

In the printer having the above structure, the rotation of the drive shaft 2 is transmitted to the cam 90 via the gear mechanism 6 and the clutch mechanism 7, and the solenoid 80 connects and disconnects the clutch mechanism 7, so that it can be used when necessary. The printing color can be changed by tilting the ink ribbon cassette 30. And since such a configuration is provided in the cassette elevating unit, it is possible to select single-color printing or two-color printing simply by mounting the cassette elevating unit with a printer for monochromatic printing as a basic configuration. All parts can be common. Further, by selecting the gear ratio by the gear mechanism 6, the rotation speed of the cam 90 can be set arbitrarily.

In particular, in the above embodiment, the gear mechanism 6, the cam mechanism 9, the clutch mechanism 7 and the actuator 8 are supported by the first bracket 4, so that the cassette lifting unit can be attached to the printer body 1 extremely. Simplified,
The printer model can be easily changed. Further, since the large-diameter gear 61 meshes with the gear 27 of the drive shaft 20 only by attaching the first bracket 4 to the printer main body 1, the connection between the drive shaft 2 and the gear mechanism 6 can be easily performed.

Further, since the cam 90 is restrained in the vertical direction by the plates 91, 91, the second bracket 5
There is no play and a reliable operation can be obtained. further,
Since the paper feed motor 36 and the gears 21 and 22 for driving the drive shaft 2 are arranged on the side of the printer body 1 opposite to the cassette elevating unit, a sufficient space for the cassette elevating unit is ensured. I have. Further, the shafts 40 to 42 of the gear mechanism 6 are attached to the side plate portion 1b of the printer body 1.
Since the holes 15 to 18 are provided to be fitted with the
The positioning of the first bracket 4 can be easily performed. In addition, since the hook 46 is formed on the first bracket 4 and is engaged with the elongated hole 19 of the side plate 1b, the first bracket 4 can be attached to the printer main body 1 only with the screw 47. Further, in order to adjust the stroke of the trigger arm 86 when the solenoid 80 is energized, it is necessary to adjust the gap between the iron core 83 and the trigger arm 86. Before attaching to the frame 1, in the state of the cassette elevating unit, The stroke adjustment can be completed by loosening the screw 82 and adjusting the position of the solenoid 80. In the above-described embodiment, the cassette supporting portion 3 is configured to be tilted. However, the cassette supporting portion 3 may be configured to be vertically moved vertically.

[0031]

As described above, according to the present invention, since the cassette elevating unit for elevating and lowering the ink ribbon cassette is detachably provided on the side of the printer main body, the cassette elevating and lowering unit is basically constituted by a printer for monochromatic printing. By simply attaching the unit, a printer for two-color printing or multi-color printing can be configured, and all parts of the basic configuration can be made common. Further, by selecting the gear ratio by the gear mechanism, it is possible to obtain the effect that the rotation speed of the cam mechanism can be arbitrarily set.

[Brief description of the drawings]

FIG. 1 is a plan view showing a printer according to an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrow II in FIG. 1;

FIG. 3 is a view in the direction of arrow III in FIG. 1;

FIG. 4 is a plan sectional view showing a cassette elevating unit.

FIG. 5 is a view in the direction of arrow V in FIG. 4;

FIG. 6 is a plan view showing the printer to which the cassette elevating unit is attached.

7 is a view in the direction of arrow VII in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Frame (printer main body), 2 ... Drive shaft, 3 ... Cassette support part, 4 ... First bracket, 5 ... Second bracket, 6 ... Gear mechanism, 7 ... Clutch mechanism, 8 ...
Actuator (drive mechanism), 9 ... Cam mechanism, 15-1
7: Hole (hole), 20: Drive shaft (rotation transmission shaft), 27: Gear, 30: Ink ribbon cassette, 30b: Ink ribbon, 40-42: Shaft (gear shaft), 61: Large diameter gear (front gear) , 64... Third gear (later gear).

Claims (4)

[Claims] 1. A printer main body having an ink ribbon cassette, and a cassette elevating unit detachably provided on a side portion of the printer main body to elevate and lower the ink ribbon cassette, wherein the cassette elevating unit is attached to the printer main body. A gear mechanism for transmitting rotation of a drive shaft for driving a print head provided on the printer main body, a cam mechanism for raising and lowering the ink ribbon cassette, and a cam mechanism for rotating the gear mechanism on a bracket which is detachably mounted. And a drive mechanism for selectively connecting and disconnecting the clutch mechanism. 2. The printer main body supports the ink ribbon cassette such that a base end portion of the printer main body is rotatably supported by the printer main body so that a front end portion of the ink ribbon side can be tilted up and down. A bracket supporting the cassette mechanism, the bracket including a first bracket detachably attached to a side portion of the printer main body, and one end connected to the first bracket so as to be movable in a predetermined range in a vertical direction. And a second bracket whose other end is detachably attached to the cassette supporting portion, wherein the first bracket includes the gear mechanism, the cam mechanism,
The printer according to claim 1, wherein the printer supports the clutch mechanism and the drive mechanism. 3. The drive shaft includes a rotation transmission shaft that protrudes from a side portion of the printer main body and rotates by rotation of the drive shaft, and the gear mechanism is configured to mesh with a gear provided on the rotation transmission shaft. A gear, and a rear gear connected to the front gear via the clutch mechanism. The cam mechanism is provided on the rear gear and engages with the second bracket in the up-down direction, thereby forming the rear gear. 3. The printer according to claim 2, further comprising a cam for moving the second bracket up and down with the rotation of the gear. 4. A paper feed motor and a drive mechanism for rotating the drive shaft are disposed on a side of the printer body opposite to the cassette elevating unit, and a gear mechanism is provided on a side of the printer body. The printer according to any one of claims 1 to 3, wherein a hole is fitted to at least one of the gear shafts to position the first bracket and the printer body.