JPH0225638Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field) This invention supports a platen on a frame made of synthetic resin, and supports a guide bar so as to extend parallel to the longitudinal direction of the platen. , when a carriage with a print head mounted thereon is mounted on the guide bar and the carriage moves along the length of the platen on the guide bar, the print head prints on the printing paper on the platen. The present invention relates to a printer that is configured as follows.

(Prior Art) Conventional printers of this type have a pair of guide bars arranged at the front and rear of the carriage, one of which is made of a metal rod and supported by a frame made of synthetic resin at both ends, and the other is supported by a frame made of synthetic resin. It is integrally formed as a guide part on the top, and a band-shaped sheet made of tetrafluoroethylene resin (Teflon of Dupont) or the like is pasted on the guide part.
It is known that a part of the carriage is engaged with a sheet of the guide portion to guide the movement of the carriage along the longitudinal direction of the platen.

(Problem that the invention aims to solve) However, in this conventional printer, the guide part is made of synthetic resin and is integrally formed with the frame, so the guide part is easily distorted when the frame is molded. There were problems in that it was difficult to achieve parallel accuracy between the guide portion and the guide bar, and that after the strip sheet was attached, the sheet surface was curved due to the difference in coefficient of thermal expansion between the sheet and the guide portion. In addition, due to the difference in thermal expansion coefficient between one guide bar and the frame, there is a risk that the frame may be deformed due to changes in temperature or temperature rise due to friction between the carriage and the guide bar.
Static electricity generated in the print head and static electricity generated in the guide bar and sheet due to friction with the carriage sometimes affected various elements in the control circuit.

Structure of the invention (Means for solving the problem) This invention was made by focusing on the above-mentioned problems, and consists of a guide bar made of metal, and one end of the guide bar attached to a frame. At the same time, the other end is fitted and supported in a fitting hole of the frame so as to be slidable in the longitudinal direction, and one end on the fixed side is grounded.

(Function) Therefore, in the carriage guide device of this invention, there is no risk of distortion occurring in the frame or the guide portion, and the parallel accuracy can be easily achieved, and even when the guide bar is loosely attached to the frame, Expansion and contraction of the guide bar due to temperature changes is allowed, thereby reliably preventing the guide bar from being curved, and furthermore, static electricity from the printing area can be reliably dissipated.

(Example) Hereinafter, an example of a printer embodying this invention will be described in detail with reference to the drawings.

Now, in the printer of this embodiment, the second
As shown in FIGS. 1 to 4, a lower frame 1 is formed of synthetic resin into a substantially box-like shape with an open top, and an upper frame 2 made of synthetic resin is attached to the rear upper part of the lower frame 1. A pair of left and right fitting holes 3 are formed on the rear wall of the lower frame 1, and a pair of left and right projections 5 are formed on the rear surface of the upper frame 2 to fit into the fitting holes 3 via elastic caps 4 made of garbage. has been done. lower frame 1
A pair of left and right rubber elastic cylinders 6 are fitted to the front edges of the upper frame 2. By screwing screws 8 from the upper surface of the upper frame 2 into the nuts 7 held at the lower ends of the upper frame 2, the upper frame 2 is fixed. It is removably fixed on the lower frame 1.

A bottom cover 10 is fixed to the opening 9 provided at the bottom of the lower frame 1 with a plurality of screws,
A circuit board 11 that supports the control circuit of this printer is fixed to the upper surface thereof by the screws. A power supply unit 13 is removably attached to the front right end of the lower frame 1, and includes power supply-related electrical parts such as a transformer, a capacitor, and a switch. To the left of the power supply unit 13, a front cover 14 is attached to the front upper part of the lower frame 1 so that it can be opened and closed, and a transparent cover 15 is attached to the front upper part of the upper frame 2 so that it can be opened and closed.

As shown in FIGS. 2 to 4, a platen 16 is rotatably supported between the left and right side walls 2a and 2b of the upper frame 2 via a bearing member 17, and an operation knob 18 is attached to the left end of the platen 16. There is. Platen 16
Both side walls 2a, 2b of the upper frame 2 in the vicinity of
A first guide bar 19 made of metal is installed between them and extends in parallel along the longitudinal direction of the platen 16. As shown in FIG. 4, the both side walls 2a,
A support collar 35 is fitted into each of the support holes 34 provided through the guide bar 2b, and the small diameter portions 19a and 19b formed at both ends of the first guide bar 19 are inserted and supported by the collars 35. One small diameter portion 19a is connected to the collar 35 by the first guide bar 19.
It is slidably supported to allow expansion and contraction in the longitudinal direction. Further, a ring 36 is fitted onto the other small diameter portion 19b, and a collar 35 is held between the ring 36 and the large diameter portion of the first guide bar 19, so that the small diameter portion 19b is attached to the first guide bar 19. The upper frame 2 is fixed so that the guide bar 19 cannot be moved in the longitudinal direction. so that it is located on the opposite side of the platen 16 with the guide bar 19 in between.
A second guide bar 20 made of metal and having a substantially horizontal U-shaped cross section is installed between both side walls 2a and 2b of the upper frame 2, and extends parallel to the first guide bar 19.

A metal carriage 21 is movably mounted on the first guide bar 19, and a printing guide bar 22 is mounted on the upper surface of the carriage 21. Further, as shown in FIG. 6, a metal ribbon mask 37 and a support member 40 located on the ribbon mask 37 are fixed on the carriage 21, and an ink ribbon (described later) is attached to the support member 40. A ribbon guide 38 on top of the first guide bar 19 is attached, and a contact piece 37a that is in constant contact with the outer peripheral surface of the first guide bar 19 is provided on a part of the ribbon mask 37 in a protruding manner. As shown in Figures 1, 3 and 4, the carriage 2
1, a projecting piece 23 is formed to protrude toward the second guide bar 20, and an engaging body 24 is provided at the tip of the protruding piece 23.
is attached. As shown in FIG. 3, this engaging body 24 engages with the upper side of the second guide bar 20 from above and below, and the second guide bar 20 guides the carriage along the longitudinal direction of the platen 16. 21 movement is now guided. A ribbon cassette 25 is removably mounted on the upper frame 2 so as to be located on the opposite side of the platen 16 with the print head 22 in between. An ink ribbon 26 is housed inside the ribbon cassette 25, and a portion of the ink ribbon 26 comes out of the ribbon cassette 25 and is placed between the platen 16 and the print head 22.

As shown in FIG. 4, a metal support plate 27 is attached to the lower right side of the upper frame 2, a platen drive motor 28 is supported on its right side, and a carriage drive motor 29 is supported on its lower surface.
is supported. When the platen drive motor 28 is rotated, the platen 16 is rotated in either forward or reverse direction via the reduction gear mechanism 30.
A feed is applied to the printing paper on the platen 16.
Further, when the carriage drive motor 29 is rotated, a reduction gear mechanism (not shown) and a toothed pulley 3 are rotated.
1 and the carriage 21 via the toothed belt 32.
is moved either to the left or right in the longitudinal direction of the platen 16, and the upper frame 22 on the carriage 21 prints on the printing paper on the platen 16 via the ink ribbon 26. Furthermore, when the carriage drive motor 29 rotates, a ribbon feed shaft 33 on the ribbon cassette 25 is rotated in one direction via a reduction gear mechanism (not shown), so that the ink ribbon 26 is fed by a predetermined amount. .

Next, the support structure of the second guide bar 20 will be explained. As shown in FIGS. Both ends of the second guide bar 20 are fitted into the two ends. A fixing piece 42 having a screw hole 42a is formed protruding from the right end of the second guide bar 20, and a mounting piece having a through hole 43a is formed on the support plate 27 on the lower surface of the upper frame 2 so as to correspond to the fixing piece 42. 43 is formed by bending. Then, by screwing the fixing screw 44 into the screw hole 42a of the fixing piece 42 through the through hole 43a of the attachment piece 43, the right end of the second guide bar 20 is attached to the upper frame 2 via the support plate 27. Although it is fixed,
The left end of the second guide bar 20 is supported so as to be relatively movable while being screwed into the fitting hole 41, so that the second guide bar 20
It is designed to allow expansion and contraction in the longitudinal direction.

Furthermore, in this embodiment, as is clear from FIG. The vertical length of the side groove part 41b of the second guide bar 0 is larger than the length of the side piece part 20b of the second guide bar 0, and the longitudinal length and groove width of the lower groove part 41c of the fitting hole 41 are larger than the length of the side groove part 41b of the second guide bar 20. The length and plate thickness of the lower piece 20c of the second guide bar 20 are larger than that of the upper piece 20a of the second guide bar 20.
With the base end side of the side piece 20b as a reference, the upper piece 20a, the side piece 20b, and the lower piece 20c are allowed to expand and contract in the front-rear direction and the up-down direction due to temperature changes.

Further, the support plate 27 is connected to a ground terminal (not shown) of the power supply section of this printer, and therefore the second guide bar 20 is connected to the support plate 27.
By fixing the second guide bar 20 to the ground terminal, the second guide bar 20 is also electrically connected to the ground terminal.
6. Static electricity in the print mechanism section including the print head 22 and the like and the second guide bar 20 is released through the second guide bar 20. Furthermore, the fourth
As shown in the figure, a contact piece 39 made of a springy metal material is attached to the support plate 27, and its tip is in contact with one end surface of the first guide bar 19, and the contact piece 39 is connected to the printing mechanism and the first guide bar 19. Static electricity in the bar 19 portion is released via the contact piece 39.

Therefore, in the printer of this embodiment, the guide bars 19, 20 are not bent due to molding distortion or temperature changes during manufacturing or use, and the guide bars 19, 20 are always aligned with the guide bars 19. The carriage 21 is arranged parallel to the axis and guided by the guide bars 19 and 20.
is smoothly moved along the longitudinal direction of the platen 16, and the printing head 22 accurately prints on the printing paper on the platen 16. Furthermore, static electricity generated during paper feeding, carriage movement, etc. is reliably released through the first and second guide bars 19 and 20, which may adversely affect the control circuit or cause discomfort during operation. You can prevent this from happening.

It should be noted that this invention is not limited to the configuration of the above-mentioned embodiments, and it is also possible to embody the invention by changing the configuration of each part arbitrarily within a range that does not depart from the spirit of this invention.

Effects of the invention As detailed above, this invention consists of a guide bar made of metal, one end of which is fixed to a frame, and the other end fitted and supported by the frame so that it can slide in its longitudinal direction. By grounding one end of the fixed side, there is no risk of distortion in the frame, and the parallelism between the guide bars and the platen can be easily achieved, and the state in which the guide bar is assembled to the frame can be easily achieved. This allows the guide bar to expand and contract due to temperature changes, thereby reliably preventing the risk of bending the guide bar.It also has the advantage of dissipating static electricity from the printing mechanism and eliminating any negative effects on the control circuit. be effective.

[Brief explanation of the drawing]

Figure 1 is a partially exploded perspective view showing the guide bar mounting structure in a printer embodying this idea;
Fig. 2 is a perspective view showing the entire printer, Fig. 3 is a vertical sectional view of the main parts of the printer, Fig. 4 is a partial plan view, and Fig. 5 shows how the guide bar fits into the fitting hole on the side wall. Partial sectional view showing enlarged state, No. 6
The figure is an exploded perspective view of the printing mechanism section. 2... Upper frame, 16... Platen, 19... First guide bar, 20... Second guide bar, 21...
Carriage, 22...Print head, 27...Support plate,
41... Fitting hole, 42... Fixing piece, 44... Fixing screw.

Claims (1)

[Claims for Utility Model Registration] 1. A platen 16 is supported on a frame 2 made of synthetic resin, and a guide bar 19 is provided to extend parallel to the longitudinal direction of the platen 16.
A carriage 21 is mounted on the guide bars 19 and 20, and the carriage 21 supports the guide bar 1.
In this printer, the print head 22 prints on the print paper on the platen 16 when the guide bars 19, 20 are moved along the longitudinal direction of the platen 16, and the guide bars 19, 20 are made of a metal material. One end of the guide bars 19, 20 is fixed to the frame 2, the other end is fitted and supported to the frame 2 so as to be slidable in the longitudinal direction thereof, and one end of the fixed side is grounded. carriage guide device. 2 The guide bars 19 and 20 are connected to the carriage 21
There are two cartridges at the front and rear of the printer, each electrically connected to a support plate 27 on which a carriage drive motor 29 is mounted, and grounded via the support plate 27. Guidance device.