JPS6234160B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a frame/ground connection mechanism for a printer device, and more particularly to a frame/ground connection mechanism for a printer device, and in particular, a metal structure having a carriage movable in the printing direction and a vibration absorbing member for preventing vibrations caused by the movement of the carriage. The heat dissipating member, the metal frame, and the cover in a printer device having a frame, a control printed board attached to the metal frame, a heat dissipating member provided in proximity to the printed board, and a cover covering the metal frame. relating to electrical and thermal connection mechanisms between

There are metal parts such as frames, heat sinks, and metal covers inside system equipment, but it is known that if these metal parts are electrically floating, they become extremely vulnerable to external noise.
In particular, to prevent static electricity, it is important to apply potential to all metal parts.

Conventionally, in order to eliminate floating metal, system equipment uses braided wires, conducting wires, etc., and connects them to the ground using screws.

For example, in the printer device shown in FIG. 1, the heat sink 2 is installed at the rear facing the outside air,
Further, a metal cover 1 covers the outer surface of the device. A carriage and a key are provided on the other side of the platen 3.

FIG. 2 is a cross-sectional structural diagram seen from direction A in FIG. 1.

Normally, the control printed board (hereinafter simply referred to as "printed board") 5 and the part 8 that stops the heat sink 2 are in contact with the ground line of the printed board 5, so from a DC perspective, the impedance is low, and the heat sink 2 can also be at ground level. However, when a discharge current due to electrostatic noise flows through the heat sink 2, the impedance is too high for it to flow through the ground of the printed circuit board 5 via the set screw. Therefore, as shown in FIG. 2, the heat sink 2 and the frame 4 and the frame 4 and the cover 1 are connected by screws using a braided wire having a width of 5 to 12 mm or a conducting wire 7 having an AWG of #16 or more. Note that 6 and 6' are rubber feet.

However, at this level, if high frequency noise of 5 MHz or more flows into the housing 1 or the heat sink 2, the influence of the inductance of these conductors 7 cannot be ignored, and trouble will occur in the control section of the printed board 5. Resulting in.

Further, in the above-mentioned conventional technology, regarding heat radiation from the heat sink 2, only heat radiation by radiation and convection is taken into consideration, and a sufficient heat radiation effect may not be obtained in some cases.

The present invention solves the above-mentioned problems in the frame-ground connection mechanism of conventional printer devices, and eliminates the risk of trouble occurring in the control section when receiving high-frequency noise such as electromagnetic induction due to arc discharge. It is an object of the present invention to provide a frame-ground connection mechanism for a printer device that has excellent heat dissipation effects.

The above-mentioned objects of the present invention include a carriage movable in the printing direction, a metal frame having a vibration absorbing member for preventing vibrations accompanying the movement of the carriage, and a control printed board attached to the metal frame. and a printer device having a heat dissipation member provided in close proximity to the printed board, and a cover covering the metal frame, wherein the heat dissipation member, the metal frame, and the cover are connected by a conductive flexible member. This is achieved by a frame-to-ground connection mechanism of the printer device, which is characterized by:

Embodiments of the present invention will be described below with reference to the drawings.

Figure 3a is a sectional view illustrating the frame-ground connection method of the present invention, Figure 3b is a front view of a conductive leaf spring used for connection, and Figure 3c is a side view of the conductive leaf spring. .

Ideally, to prevent high-frequency noise such as static electricity, it is desirable to cover the control section with a casing, and to keep the distance between the casing and the control section at least 10 cm. If there is a distance of about 10cm between the control unit and the housing, a discharge current due to static electricity will be generated in the housing for several nanoseconds.
The control unit will not malfunction due to the induced current even if about 50A flows for several tens of nanoseconds. However, normally there is no such space, and in printers such as the one shown in Figure 1, there are heat generation problems and restrictions such as reducing the external size, so conductive wires are used to connect the heat sink. The frame or cover is connected to form a low impedance to induced currents.

3a to 3c show an example in which the heat sink 2, frame 4, and cover 1 are connected using a phosphor bronze plate spring 11. As shown in Figure 3b,
Phosphor bronze plate spring 1 having the same width as the heat sink 2
1 to connect the heat sink 2, frame 4 and cover 1 as shown in FIG. 3a.

As shown in FIGS. 3b and 3c, the phosphor bronze plate spring 11 having the same width as the heat sink 2 has a part that is screwed to the heat sink 2, a part that makes surface contact with the tip of the frame 4, and a part that makes surface contact with the cover 1. The contacting parts are bent at a certain angle, and each has a screw hole and a finger section divided into many parts.

Note that the material for connecting the metal parts is not limited to a phosphor bronze plate, and any flexible material having conductivity may be used.

In this way, since the springy material is provided for the entire width of the heat sink 2, compared to the conventional case of fixing the braided wire with screws, it becomes a surface contact instead of a point contact, and a flat spring. As a result, the inductance becomes almost negligible, and since the leaf spring covers the printed board 5 by the entire width of the heat sink 2, it has a shielding effect and electrostatic shielding against external radiation noise, etc. gives the effect of

Also, regarding the heat dissipation effect, since the leaf spring 11 is attached to the heat sink 2 for the entire width thereof, a large amount of heat dissipation by conduction can be expected.

From the viewpoint of maintainability, since the printed board 5 and the heat sink 2 are integrated, it is easy to handle by simply pulling out the printed board 5, without having to remove the contact between the frame 4 and the cover 1. I can do it. Furthermore, the frame 4 has many cracks (finger parts) at the end of the leaf spring 11.
It is designed to contact the cover 1 etc. with uniform force.According to experiments, a thickness of 0.35mm of phosphor bronze is sufficient, and the bending angle can be set according to the structure of the device. .

In the printer main body, when the carriage moves left and right, the frame 4 also swings left and right, so if the cover 1 is directly attached to the frame 4, the cover 1 will also swing left and right. The rubber feet 6' are
To prevent this shaking, frame 4 and cover 1
It was provided as a buffer between the two.

As described above, according to the present invention, there is provided a carriage movable in the printing direction, a metal frame having a vibration absorbing member for preventing vibrations accompanying the movement of the carriage, and a metal frame attached to the metal frame. In a printer device having a printed board, a heat dissipating member provided near the printed board, and a cover covering the metal frame, an electrically conductive flexible Since the connection is made with a flexible material, it is possible to form a low impedance section for high frequency current, and there is no need to worry about trouble occurring in the control section when receiving high frequency noise such as electromagnetic induction due to arc discharge. This has the remarkable effect of realizing a frame-ground connection mechanism for a printer device with excellent heat dissipation effects.

[Brief explanation of the drawing]

FIG. 1 is a rear perspective view of a printer device, FIG. 2 is a sectional view showing a conventional frame-ground connection method, and FIG. 3 is an explanatory diagram showing an embodiment of the present invention. 1: Cover, 2: Heat sink, 3: Platen, 4: Frame, 5: Printed board, 6, 6':
Rubber feet, 7: Braided wire, conductive wire, 8: Part that fixes the printed board and heat sink, 9: Frame fixing screw, 11: Leaf spring.

Claims (1)

[Claims] 1. A carriage movable in the printing direction, a metal frame having a vibration absorbing member for preventing vibrations caused by the movement of the carriage, and a control printed board attached to the metal frame. and,
a heat dissipation member provided close to the printed board;
A frame-ground connection mechanism for a printer device having a cover that covers the metal frame, wherein the heat dissipation member, the metal frame, and the cover are connected by a conductive flexible member. 2. The frame-ground connection of a printer device according to claim 1, wherein the conductive flexible member is composed of a plate spring having fingers divided into a plurality of pieces. mechanism. 3. A side of the conductive flexible member having a plurality of divided fingers is connected to the metal frame and the cover, and the opposite side thereof is connected to the metal frame and the cover, and the opposite side is connected to the metal frame and the cover.
2. The frame-ground connection mechanism for a printer device according to claim 1, wherein the frame-ground connection mechanism is connected to the heat radiating member.