JPH0329166Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a ribbon cassette attaching/detaching mechanism used in a serial type thermal printer.

Prior Art Usually, when setting a printing ribbon in an impact printer, the ribbon cassette is mounted directly onto a printing carriage, or the ribbon cassette is directly attached to the printer body instead of the printing carriage. However, if the ribbon cassette is attached directly to the carriage, it is relatively convenient to attach and remove the ribbon from the printing section, but this increases the weight and size of the carriage, making the printer larger. For this reason,
The carriage feed motor must be large and consumes a lot of power. Furthermore, since the carriage itself must be equipped with a ribbon feeding mechanism, there is an inconvenience that the structure of the carriage becomes complicated.

On the other hand, as a conventional example of an impact printer in which a ribbon cassette is attached to a printer body, there is a detachable mechanism shown in FIG. 1, for example.

In the illustration, the reference numeral 1 indicates a ribbon cassette, which is in the form of a horizontally elongated case so that both areas of the printer body 1a can be placed across the side plate 2 located on both sides of the printer body. There is. On the side surface of the printer main body 1a, although only one side is shown in the figure, there are a locking part 3 made of a rigid protrusion and a locking part 4 made of an elastic protrusion, which are arranged front and back as shown in the figure. They are provided in both areas. Further, the side plate 2 is provided with corresponding engaging portions 5 and 6 into which both of the above-mentioned locking portions can be fitted. Note that 7 is a printing ribbon led out of the cassette main body 10 to be supplied to the printing position.

However, in this conventional example, the ribbon cassette 1 is attached to and detached from the side plate 2 by first attaching the rigid locking part 3 to the engaging part 5 with the ribbon 7 side facing down, and then attaching the ribbon cassette 1 to the side plate 2. The locking part 4 of the ribbon cassette 1 is fitted into the engaging part 6 while being elastically deformed very strongly, and when the ribbon cassette 1 is removed, the locking part 4 side is pressed against the elastic deformation of the locking part 4. must be lifted. Therefore, when the ribbon cassette 1 is removed, a rotating operation is applied to the ribbon cassette 1 that presses the ribbon 7 side further downward, and the thin ribbon 7 led out to the printing section of the cartridge is There is a problem in that the ribbon may be unnecessarily pressed against the printing section or other mechanical sections, and the portion of the ribbon that has been led out may be damaged or rendered unusable.

Therefore, the attachment and detachment of the ribbon cassette 1 is performed only by rotating the same locking part 4, and the attachment and detachment is performed by elastic deformation of the locking part 4. This is an undesirable attachment/detachment method in terms of protection.

Purpose This invention was made in view of the above, and its purpose is to prevent the ribbon cassette from damaging the ribbon led out to the printing section when attaching and detaching the ribbon cassette to and from the printer body, making it easy to attach and detach the ribbon cassette. The reason lies in the fact that we have made it possible.

To install and remove the ribbon cassette, especially in a serial type thermal printer that can thermally print on both thermal paper and plain paper, when using plain paper, remove the ribbon cassette that stores the thermal ribbon set in the printer. It is especially convenient for

Configuration Next, this invention will be explained based on an embodiment shown in the drawings.

First, an overview of the thermal printer used in this invention will be explained.

The thermal printer shown in FIG. 4 can use both plain paper and thermal paper, and can use both cut paper and roll paper of appropriate lengths.

In the illustration, what is indicated by the reference numeral 10 is the printer body. This printer main body is housed in a printer case 11 whose outer shape is indicated by a two-dot chain line in the figure.

The printer case 11 includes the printer main body 1
0 is stored in the front, and a paper storage section A is formed behind it. Paper storage section A is printer case 1
A semi-cylindrical recess 12 is formed on the upper surface of 1,
The roll paper 13 is stored therein as shown by the two-dot chain line in the figure.

Roll paper 13 is supplied into printer main body 10 from paper supply section B. The paper supply unit B places two guide plates 17 and 18, which are also spanned between the left and right side plates 14 and 15, behind the platen 16, which is spanned between the left and right side plates 14 and 15.
are arranged one above the other toward the bottom, and are provided with a cut paper supply port that opens upward at the entrance of the upper guide plate 17, and a roll paper supply port that opens backward at the entrance of the lower guide plate 18. Become.

The paper inserted from each of the two supply ports is
The paper is guided by a paper guide mechanism C provided mainly below the platen 16, and is wound around the platen 16 from below.

For example, the paper 19 inserted from the roll paper supply port is wound around the platen 16 as shown. After the paper 19 is corrected by hand and brought into close contact with the platen 16, the paper setting mechanism D holds the paper 19 and holds it in the set state as shown by the two-dot chain line in the figure. The paper set mechanism D can move a paper presser roller 22 and a paper feed roller (not shown) (located below the platen 16) toward and away from the platen 16 by operating the knob 21 of the paper set lever 20 back and forth. ing.

In front of the platen 16, a guide shaft 23 is spanned between left and right side plates 14 and 15 in parallel with the platen 16. A carriage E is supported by the guide shaft 23 and a rail portion 25 which is a part of the front plate 24. A thermal head 26 is attached to the carriage E. The thermal head 26 faces the paper set on the platen 16.

The carriage E is driven by a carriage feed mechanism F, is guided by a guide shaft 23, and is moved to the platen 1.
Move horizontally along 6. Carriage feed mechanism F
The rotation of the carriage feed motor 27 passes through the carriage feed wheel train 28 to the left and right pulleys 29, 30.
The carriage feed belt 3 is transmitted to one of the pulleys 30 and is stretched between the pulleys.
Turn 1 to move the carriage E attached to that belt.

On the other hand, the platen 16 is rotated by the platen feeding mechanism G in the direction of the arrow in the figure. The platen feed mechanism G transmits the rotation of the platen feed motor 32 to the platen 16 via the platen feed wheel train 33.

When the paper set in the thermal printer is thermal paper, the thermal head 26 is pressed directly against the paper on the platen 16, and the carriage E
While moving to the right, the thermal paper on the platen 16 is sequentially colored and printed. After printing that line, the carriage E is returned to the left side, the platen 16 is rotated to start a new line, and the carriage E is moved to the right side again to print. By repeating this process, printing is sequentially performed on the thermal paper.

On the other hand, when the paper set in the thermal printer is plain paper, a ribbon cassette H is attached to the left and right side plates 14 and 15 and placed on the printer main body 10.
Set. The ribbon cassette has a thermal ribbon 35 stored in a cassette body 34, and when it is set, the ribbon guide roller 36 of the carriage E guides the thermal ribbon 35, interposing the thermal ribbon 35 between the thermal head 26 and the paper. let Then, the thermal head 26 is pressed against the paper on the platen 16 via the thermal ribbon 35, and the carriage E
While moving the ribbon to the right, ink from the thermal ribbon 35 is sequentially transferred onto the plain paper on the platen 16 to print. After printing that line, the carriage E is returned to the left side, and the ribbon feeding mechanism 1 feeds the thermal ribbon 35 in the direction of the arrow in the figure.
Turn 6 to start a new line, and print while moving carriage E to the right again. By repeating this process, printing is performed sequentially on plain paper.

The ribbon feeding mechanism 1 transmits the rotation of the ribbon feeding motor 37 to the drive shaft 39 via the ribbon feeding wheel train 38. The drive shaft 39 is connected to a winding drive roller in the ribbon cassette H when the ribbon cassette H is set on the printer main body 10.

Next, details of the ribbon cassette H will be explained.

As shown in FIGS. 5 and 6, in the ribbon cassette H, a heat-sensitive ribbon body 35a, which is located on the right side of the cassette body 34 and is wound in a pancake shape, is inserted into a boss shaft 40 of the cassette body. The tip of the ribbon pulled out from this is guided by the guide roller 4.
1, 42, and 43 to reach the derivation guide 44. The ribbon led out of the cassette main body from this lead-out guide 44 is led out over substantially the entire length of the cassette main body 34 toward the opposite lead-out guide 45 located at an opposing position. Winding drive roller 46 and pinch roller 47
, and is wound onto a winding spool 48. Note that the pin roller 47 is pressed toward the drive roller 46 by a spring 49.

A tension lever 50 is provided between the lead-out guide 44 and the guide roller 43 to prevent the thermal ribbon 35 led out of the cassette body 34 from becoming loose. This tension lever is
A support shaft 51 is used as a fulcrum, and tension is applied to the heat-sensitive ribbon 35 whose lever tip is led out by pulling a spring 52.

The driving roller 46 is provided with a connecting portion 53 at the lower part to which the driving shaft 39 of the ribbon feeding mechanism 1 can be connected and transmitting rotation of the shaft, and at the upper part to which the driving shaft 39 of the ribbon feeding mechanism 1 can be connected.
6 is provided with a knob shaft 54 that can be manually rotated.
The drive roller 46 is further provided with a belt 55 for rotating the spool 48 for winding the ribbon.
A pulley 56 is provided to hang the pulley 56,
The belt 55 and the pulley 57 on the spool 48 side are fitted into a recess 58 provided at the bottom of the cassette body. The drive roller 46 further includes a slider 59 for preventing the ribbon from wrapping around the drive roller due to pressure contact with the pinch roller 47.
are in sliding contact with each other, and the tip of the slider 59 engages with a groove 60 recessed in the drive roller 46.

On the spool 48 side, a fixed shaft 61 is located in the recess 58 and protrudes, and a rotating part 62 having a pulley 57 is pivotally attached to this. The rotating part 62 has a claw 6
3 is provided in a protruding manner, and a spool 48 removably attached to this rotating portion has a structure capable of engaging with this pawl 63. Note that the amount of ribbon wound up by the spool 48 will change as the outer diameter of the spool increases, but
6 is allowed by the slip of the belt 55.

On the other hand, a sensor 6 that can detect the end of the ribbon is attached to the ribbon portion pulled out from the heat-sensitive ribbon body 35a.
4 can be set. The sensor 64 is disposed on, for example, the side plate 15 of the printer main body 10 via a bracket or the like, and is attached to the ribbon cassette H.
When attached to the predetermined position of the printer main body 10,
A sensor 64 extends into the cassette through a hole 65 in the bottom of the cassette body 34 and optically detects the presence of the passing ribbon.

Reference numeral 66 denotes a spare ribbon body for replacement or replenishment, which is stored in the cassette main body 34 as a spare. This spare ribbon body may be stored in a space in the cassette body separated by partitions 67, 67, or, for example, the same as the boss shaft 40 may be provided in this space and inserted into it. You can also store it. Note that in this case, the partition 67 is unnecessary. The spare ribbon body 66 may be used by attaching it to the position of the heat-sensitive ribbon body 35a, or by directly pulling out the spare ribbon from the empty space shown in the figure toward the guide roller 41 side. . Further, when pulling out the ribbon from the spare position, a guide roller may be provided at or near the empty space position as necessary.

Although the cassette main body 34 is shown with the top cover 34a removed in FIG. 5, the top cover is detachably attached to the cassette main body 34 via hinge parts 68, 68. The upper lid 34a is provided with two hooks 69, as shown in FIG. 7, which engage the notches 70 of the cassette body 34.

To attach the ribbon cassette H to the cassette main body 10, connect the locking parts 71 and 72 provided on both sides of the cassette main body 34 to the engaging parts 7 of the side plates 14 and 15.
3, 74, and by this attachment, the driving roller 4 of the ribbon cassette H
6 is connected to the drive shaft 39 of the ribbon feeding mechanism I on the printer main body 10 side. Of course, the sensor 64 also protrudes into the corresponding hole 65.

To attach the ribbon cassette H, as shown in FIG. 8, first the first locking part 71 is inserted into the first engaging part 73 from above. In this case, the thermal ribbon 35 that has been led out is actually stretched between both the lead-out guides 44 and 45. Then,
The front side of the cassette body 34 is pressed downward and the second locking part 72 is pushed into the second engaging part 74 from above. In this case, the first locking part 71 and the first engaging part 7
3, the hook part 71a of the first locking part is the locking point (P1)
The second engaging part 72 is engaged with the first engaging part 73 with the second engaging part 74 as a contact point.
The hook portions 72b and 72c divided by the second
It engages with the engaging portion 74. Therefore, the second locking portion 72
can be elastically bent in the diameter reduction direction by the split groove 72a. Second locking portion 72 for second engaging portion 74
The anchoring is done by dividing it into two anchoring points (P2) and (P3) as shown in Fig. 9. Moreover, this engagement is such that the hook portions 72b and 72c are mutually connected to the second engaging portion 7.
4 in the front-back direction as shown in the drawing.

In the above, a part of the second locking part 72 has a cut for relieving the contact pressure of the second locking part 72 that is pushed into the second engaging part 74 using the locking point (P1) as a fulcrum. A surface 72d is provided. When engaged with the second engaging portion 74, this cut surface extends along the inclined surface 74a on the second engaging portion 74 side.
This helps to alleviate the press-fitting resistance of the second locking part 72 that is press-fitted therein.

After installing the ribbon cassette H, the thermal ribbon 35 led out of the cassette main body 34 is transferred to the thermal head 26 of the carriage E, the ribbon guide rollers 36, 36a, and the auxiliary rollers 36b, 36c.
For example, as shown in FIG. This ribbon wrapping is performed by pinching the led-out thermal ribbon 35 and pulling it out by an appropriate length from the thermal ribbon body 35a side, loosening the ribbon, and then manually wrapping the ribbon.
After this wrapping, the ribbon is pinched by the knob shaft 54 and the slack of the ribbon is wound onto the spool 48 side.

In this embodiment, when the printing start switch is turned on, the ribbon feeding mechanism I is driven to take up the slack in the ribbon in response to the carriage E returning to its home position on the left. This allows the slack at the initial stage of ribbon setting to be automatically taken up. This ribbon feeding mechanism I is driven each time the printing starts and the carriage E finishes printing each "line" and returns to the line feed position. It will be rolled up. In this case, the amount of winding of the ribbon is done in accordance with the moving space of the carriage E, and accordingly, the unused ribbon portion is unwound each time in accordance with the amount of winding. In the above, the heat-sensitive head 26 is always connected to the platen 11 except when the heat-sensitive head 26 is moved in the printing direction by the elasticity of an elastic member, which will be described later.
It is mounted away from the side. This relationship is shown in FIGS. 10 to 12. Therefore, when winding the thermal ribbon 35, the ribbon is released from the pressure exerted by the thermal head 26, thereby eliminating the ribbon winding load and protecting the ink layer of the ribbon as it is being fed out.

The carriage E is moved by turning on a printing start switch, causing the thermal head 26 to rotate and come into contact with the platen via a solenoid, which will be described later, and by driving the carriage feeding mechanism F, which is movable at the same time. The carriage E continuously moves to the right by the operation of the feeding mechanism, and sequentially squeezes the led out thermal ribbon 35 with the thermal head 26 to transfer the ink layer to the paper 1.
9, and a heating element provided on the printing surface of the thermal head sequentially thermally transfers the desired print onto the paper surface. When one line of printing is completed, the carriage feeding mechanism is reversed and the carriage E returns to the line feed position, and this reciprocating movement is repeated thereafter.

The thermal head 26 is detachably attached to the carriage E at a position along the platen 16, as shown in FIGS. 10 to 12, and 75 is a head holder for attaching and detaching the thermal head. This head holder is pivotally supported by brackets 76a, 76a of a carriage block 76 via a mounting shaft 77.
The head holder 75 has head pressing springs 78 and 7 that prevent the heat-sensitive head 26 inserted therein from being pulled out.
8 is installed. Therefore, the head holder 75
The heat-sensitive head 26 is attached to the shoulder 7 of the head.
9, 79 are sockets 80, 80 of the head holder 75
It can be inserted from above into the head, and a head pressing spring 78 prevents its removal.

The lower part of the head holder 75 further includes an elastic member 81 for rotating the head holder itself counterclockwise in the direction shown in the figure, and a base 84 having a connector 83 into which a connecting pin 82 of the heat-sensitive head 26 set in the head holder 75 can be inserted. However, screw hole 8
It is fixed throughout 5. Note that a flexible printed board is connected to the connector 83 (not shown).

The elastic member 81 includes a first elastic portion 81a extending upward and a second elastic portion 81c located between the base portion 81b.
Reference numeral 86 denotes a hole bored in the elastic member located between the elastic parts 81a and 81c, and an operating rod 88 to which a traction member 87 is attached to the tip is inserted into this hole as shown in FIG.

The operating rod 88 is housed in a solenoid 89 and is attached to the lower part of the carriage block 76 via a solenoid holder 90. Note that the tongue piece 91 provided integrally with the solenoid holder 90
The carriage feed belt 31 is sandwiched between the side surface of the carriage block 76 and the belt and the carriage block are connected. Carriage E will move together with the belt in this connection.

In the above, the first elastic part 81 of the elastic member 81
In its natural state, a extends upward as shown in FIG. 11, but by assembling it to the carriage block 76 as shown in FIG. be done. Then,
The head holder 75 rotates counterclockwise about the mounting shaft 77 due to the elasticity of the elastic member, and the so-called heat-sensitive head 26 moves away from the platen 16. Further, on the front side of the thermal head 26 (on the side facing the platen), heating elements 26a for printing are arranged in an appropriate number of dots.

When the thermal head 26 comes into contact with the platen 16, when a print start switch is turned on, the solenoid 89 is energized and the operating rod 88 is moved back to the left in the figure. Then, the pulling member 87 collides with the elastic member 81 in the hole 86 portion, and the first elastic portion 81
Pull the elastic member to the left against the elasticity of a.
Then, the head holder 75 is rotated clockwise while the elastic member 81 is bent by the traction. 1st
The dashed dotted line in Figure 0 shows the state at the time of printing. Then,
During printing, the thermal head comes into contact with the platen due to the traction pressure of the solenoid. In addition, in the elastic member 81 that is bent by the traction of the solenoid 89, the elasticity of the second elastic part 81c is set to be stronger than that of the first elastic part 81a, and this traction pressure by the solenoid 89 is applied to the second elastic part 81c. The print contact pressure of the thermal head 26 is increased by pulling the print head more strongly while being flexible.

On the other hand, when the carriage E finishes printing in the "line" direction and returns to the line feed position, the power supply to the solenoid 89 is turned off, and the head holder 75
The thermal head 26 is rotated counterclockwise due to its elasticity, and the thermal head 26 is separated from the platen side. Therefore, the above-mentioned operation of the head holder 75 is performed in correspondence with the reciprocating movement of the carriage E.

To remove the ribbon cassette H, as shown in FIG. 13, pull up the front and rear of the cassette body 34, that is, the so-called first locking portion 71 side. In this case, the thermal head 26, each roller 36,
The ribbons hung on 36a, 36b, and 36c shall be removed from these. Note that this removal of the ribbon cassette H is performed, for example, when cleaning the carriage E side or when using thermal paper for the paper 19.

As shown in the figure, when the first locking part 71 side of the ribbon cassette H is lifted, the locking point (P1) between the first locking part 71 and the first engaging part 73 is located at the hook part of the first engaging part 73. Along with this, the other second locking part 72 is elastically bent, and the cassette main body 34 moves slightly in the direction of the arrow (X), and the first locking part 71 is pulled out. Make it easier. Therefore, the first locking portion 71 can be pulled out as described above without causing the strong shock seen in the conventional configuration, and the rotation of the ribbon cassette H can be performed without causing the ribbon side that has been pulled out. Since it can be done toward the upper space, the ribbon can be easily removed without having to collide with other mechanical parts.

The cassette main body 34 from which the first locking portion 71 has been released in this manner is then rotated further upward as shown in FIG. 14. Then, the rotation is such that the cut surface 72d on the second locking part 72 side is connected to the second engaging part 7.
4, and when it reaches this state, simply pull the cassette body 34 upward. Then, when the second locking part 72 and the second engaging part 74 are engaged in this state, the pulling out resistance on the locking point (P2) side can be extremely minimized, so that the second locking part 72 can be pulled out easily. The output resistance is approximately only on the hook portion 72b side. Therefore, this extraction resistance at the second locking portion 72 is reduced by the ribbon cassette H.
The degree of engagement can be reduced by approximately half compared to when the side plates 14 and 15 are set. Therefore, the force needed to remove the ribbon cassette is extremely small, and the reaction force exerted on the ribbon cassette H can be largely eliminated.

Effects The attachment and detachment of the ribbon cassette according to this invention is as described above, so although the ribbon cassette can be attached and detached from the printer body through the locking part protruding from the side of the cassette body, Since the force needed to attach or detach the ribbon cassette is extremely small, it is extremely easy to attach or detach the ribbon cassette. Further, according to this invention, it is possible to eliminate the drawback that when attaching and detaching the ribbon cassette, the heat-sensitive ribbon drawn out from the cassette body is unnecessarily damaged. Therefore, the practicality of this invention is extremely significant in attaching and detaching ribbon cassettes used in serial type thermal printers.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams of the conventional example, Figure 4 is a perspective view showing an overview of the ribbon cassette and thermal printer used in this invention, and Figure 5 is an enlarged plan view of the ribbon cassette with the top cover removed. , FIG. 6 is a cross-sectional view of the same as the above with the upper lid arranged, FIG. 7 is a right side view of the ribbon cassette, FIGS. 8 and 9 are explanatory diagrams for installing the ribbon cassette, and FIG. 10 is a view of the carriage. FIG. 11 is an exploded perspective view of the same as above; FIG. 12 is a front perspective view of the thermal head; FIG. 13 is an enlarged side view of the main parts.
14 are explanatory diagrams for removing the ribbon cassette. 14, 15...Side plate, 34...Cassette body,
71...first locking part, 71a, 72b, 72c...
...Hook part, 72...Second locking part, 72d...Cut surface, 73...First engagement part, 74...Second engagement part.

Claims (1)

[Claims for Utility Model Registration] A first engaging part and a second engaging part are formed on the side plate of the printer body, and a first engaging part and a second engaging part are respectively capable of being engaged with these engaging parts. In the ribbon cassette attachment/detachment mechanism, the ribbon cassette is attached to the first locking portion, and the ribbon cassette is attached to the second locking portion.
A hook portion is formed that reduces the degree of engagement with the first engaging portion when moving toward the locking portion, and a split groove is provided in the second locking portion to allow flexibility in the diameter reduction direction when attached/detached. A ribbon cassette attaching/detaching mechanism, further comprising a cut surface that reduces the degree of engagement with the second engaging portion when the ribbon cassette is tilted at a predetermined angle with respect to the printer main body.