JP3066868U - High pass filter - Google Patents

Abstract

(57) [Problem] To provide a high-pass filter for a CATV network which is sufficiently effective in preventing noise contamination. SOLUTION: In a high-pass filter in which a filter element is accommodated in a main body case 1 and a connector plug and a seat are formed on an end surface of the main body case, a circuit board 10 on which the filter element is mounted, and the circuit board And a ground spring 11 for elastically contacting at a plurality of locations distributed with respect to the main body case and connecting the circuit board to the main body case. filter.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a high-pass filter used in a CATV network or the like, and particularly to a high-pass filter used to prevent noise from entering a CATV network from a terminal.

[0002]

[Prior art]

 In recent years, CATV, which distributes TV programs via a network, has been increasingly used for the Internet. This is to use the network that is normally used as a down line from the CATV station to the receiver, that is, a network used as a one-way line, as an up line for transmitting information from the receiver, that is, as a so-called two-way line. .

In this case, the CATV network is connected to a large number of recipients, and it is necessary to prevent a signal transmitted from each recipient from being mixed into or affecting a line to another recipient. is necessary.

Here, while the frequency for CATV is 70 MHz or more, the frequency used for the Internet is completely separated to 55 MHz or less. And a filter is provided for that.

[0005] Therefore, if this filter works well, the problem of signal contamination should be solved.

[0006]

[Problems to be solved by the invention]

 However, this type of filter provided conventionally cannot sufficiently cope with the contamination of Internet signals, and there is a problem of noise contamination as CATV. The present invention has been made in view of the above points, and has as its object to provide a high-pass filter for a CATV network that is sufficiently effective in preventing noise contamination.

[0007]

[Means for solving the problem]

 In order to achieve the above object, according to the present invention, in a high-pass filter in which a filter element is accommodated in a main body case and a connector plug and a seat are formed on an end face of the main body case, a circuit board on which the filter element is mounted is provided. And a ground spring mounted on a side edge of the circuit board and elastically contacting at a plurality of locations distributed with respect to the main body case, and grounding the circuit board to the main body case. The feature is to provide a high-pass filter.

[0008]

[Embodiment of the invention]

 FIG. 1 is a partial cross-sectional view of an embodiment of the present invention. In this embodiment, a metal main body case 1 has a substantially cylindrical outer shape, a hexagonal prism-shaped tool abutting portion slightly near the center, an F-type connector seat at the upper end in the figure, and an F-type connector at the lower end in the figure. A plug is formed therein and houses the filter element.

In FIG. 1, a metal screw case 2 is press-fitted into the upper end of the main body case 1 in the drawing, and an O-ring 3 is inserted into a butt portion of the two. Inside the screw case 2, a metal center conductor pin 6 of an F-type plug is held at a center position where the plastic spacers 4 and 5 are combined.

The pins 6 are arranged so as to extend from the left and right in the drawing and contact each other at the center, and come into contact with the center conductor when the plug is connected. Plastic combination spacers 4 and 5 are provided so as to hold the pin 6 at the center position.

In addition, a central conductor pin 8 of an F-type plug is disposed at a central position of a lower end side of the main body case 1 in the figure by a plastic spacer 7. An O-ring 9 is inserted at the end of the threaded portion of the plug so as to exhibit a waterproof effect when the plug is connected to the seat.

At the center of the main body case 1, there is provided a circuit board 10 on which the filter element is mounted and a ground spring 11 made of an elastic metal which is combined with the circuit board 10 to ground the main body case 1. Is provided. Suitable as the elastic metal is phosphor bronze.

FIG. 2 to FIG. 9 are explanatory views showing the structure of each element housed in the main body case 1 and the assembling process thereof.

FIG. 2 shows the respective structures of the circuit board 10 and the ground spring 11 and an assembly structure of both. The circuit board 10 has an elongated shape so as to be accommodated in the main body case 1, and an LC element (not shown) is assembled. The ground spring 11 is combined with each side edge of the circuit board 1. For this purpose, cutouts are provided on both side edges of the circuit board 10, and the bent portions of the ground spring 11 are engaged with the cutouts so that they are combined with each other.

The ground spring 11 is provided with contact pieces 11 a and 11 b formed by cutting and raising at both ends and side parts, respectively. The earth spring 11 contacts the circuit board 10 and presses the inner peripheral surface of the main body case 1 by elastic restoring force to connect the circuit board 10 to the main body case 1.

FIGS. 3 and 4 show a situation in which an F-shaped seat and plug are attached to the circuit board 10, and the pin 6 held at the center position of the combination type spacers 4, 5 is attached to the circuit board 10. 10 is connected to one end, and an L-shaped pin 8 of a plug is inserted and connected to the other end. Further, the circuit board 10 is soldered to the ground spring 11 at four places in the case shown in the figure, so that the connection between the circuit board 10 and the ground spring 11 is sufficient. FIG. 4 shows a state where two pins are attached through the state of FIG.

As can be seen from FIGS. 3 and 4, since the contact piece 11a is provided near the seat and the plug, the signal input end and the output end of this high-pass filter are satisfactorily grounded, and noise is reduced. Incorporation can be minimized. Further, since the contact pieces 11b are dispersedly arranged at the intermediate position between the signal input and output terminals, a ground connection measure is taken without any gap.

FIG. 5 shows a state where the spacer 7 is fitted to the L-shaped pin 8 provided at the other end of the circuit board 10 assembled in the state of FIG. After assembling to this state, it is housed in the main body case 1.

FIG. 6 shows steps for accommodating the circuit board 10 in the state shown in FIG. 5 in the main body case 1. Insert it into body case 1.

As described above, since the circuit board 10 is inserted so as to be shifted in the axial direction of the main body case 1, it is possible to prevent the circuit board 10 that is not very strong from being damaged by applying a rotational force.

FIG. 7 shows a state in which the case 2 is covered from above the screw spacers 4 and 5 after the circuit board 10 according to FIG. As can be seen from the broken portion, the contact piece 11 a of the ground screw 11 is bent and abuts on the partition wall of the main body case 1. Since the ground screw 11 is made of phosphor bronze, it has elasticity. When the screw case 2 is press-fitted, the contact piece 11a is bent to a substantially right angle state as shown in the figure, and is pressed by its elastic restoring force. .

Therefore, a sufficient ground connection is established between the circuit board 10 and the main body case 1 via the ground spring 11. That is, the circuit board 10 and the ground spring 11 are connected at four points at two points each, and the ground spring 11 and the main body case 1 are connected to the ground by three contact pieces of three pieces each.

FIG. 8 shows a state of elastic contact between the ground spring 11 and the main body case 1. The contact pieces 11a and 11b of the ground spring 11 are both bent and pressed against each other for ground connection. That is, the contact piece 11a is in pressure contact with the contact surface provided on the main body case 1 or the screw case 2, which is the ground conductor of the connector plug, and the contact piece 11b is in pressure contact with the inner peripheral surface of the main body case 1. Has become.

As a result, the circuit board 10 is properly connected to the connector plug and the ground, and appropriate noise countermeasures can be taken.

FIG. 9 shows the embodiment of FIG. 1 as a cross section looking at the plug from the seat. FIG. 9 shows the connection relationship between the circuit board 10 and the ground spring 11 and the main body case 1 and the connection relationship between the circuit board 10 and the L-shaped pins 8.

That is, the circuit board 10 is integral with the ground spring 11, and the ground spring 11 is in firm and elastic contact with the case body 1. Further, the circuit board 10 is arranged at a position slightly deviated from the center position of the main body case 1 so that the pin 7 is easily connected to the pin 7 when the pin 7 is at the center position of the main case 1. (Modification) In the above embodiment, both of the contact pieces 11a and 11b are configured to bend toward one surface side of the circuit board 10, but may be configured to bend to another surface side. Also, the number and arrangement of the contact pieces can be appropriately increased or decreased.

[0027]

[Effect of the invention]

 In the present invention, as described above, the circuit board on which the filter element is mounted is mounted on the side edge of the circuit board, and grounded by ground springs that are in elastic contact with the main body case at a plurality of distributed locations. Noise transmission caused by poor ground connection of the board can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing a first part of an assembling process of the embodiment shown in FIG. 1;

FIG. 3 is an explanatory view showing a part of the assembly process of the embodiment shown in FIG. 1 subsequent to FIG. 2;

FIG. 4 is an explanatory view showing a part of the assembly process of the embodiment shown in FIG. 1 subsequent to FIG. 3;

FIG. 5 is an explanatory view showing a part of the assembly process of the embodiment shown in FIG. 1 subsequent to FIG. 4;

FIG. 6 is an explanatory view showing a part subsequent to FIG. 5 of the assembling process of the embodiment shown in FIG. 1;

FIG. 7 is an explanatory view showing an internal state after assembly of the embodiment shown in FIG. 1;

FIG. 8 is a partially enlarged view of the situation of FIG. 7;

FIG. 9 is a cross-sectional view of the embodiment of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body case 2 Screw case 3 O-ring 4 Spacer 5 Spacer 6 Pin 7 Spacer 8 L-shaped pin 9 O-ring 10 Circuit board 11 Earth spring

Claims (6)

[Utility model registration claims] 1. A filter element is accommodated in a main body case,
A high-pass filter in which a connector plug and a seat are formed on an end surface of the main body case; a circuit board on which the filter element is mounted; and a circuit board mounted on a side edge of the circuit board and distributed with respect to the main body case. And a ground spring that makes elastic contact at a plurality of places and grounds the circuit board to the main body case. 2. The high-pass filter according to claim 1, wherein the circuit board has a notch at a side edge thereof for fitting the ground spring, and the ground spring fits into the notch and is connected to the circuit board. A high-pass filter configured to be combined. 3. The high-pass filter according to claim 1, wherein the ground spring has contact pieces at a plurality of locations separated from each other, and the contact pieces contact the main body case by these contact pieces. 4. The high-pass filter according to claim 3, wherein said ground spring has contact pieces cut and raised at both ends and side edges, and a longitudinal direction and a longitudinal direction of said circuit board are formed by elastic restoring force of these contact pieces. A high-pass filter that makes elastic contact in the direction perpendicular to the direction. 5. The high-pass filter according to claim 3, wherein the ground spring is in direct contact with the ground conductors of the connector seat and the plug by the contact pieces cut and raised at both ends. 6. The high-pass filter according to claim 1, wherein said circuit board is disposed at a position near an axis of said main body case avoiding a core wire of said connector.