GB2315860A

GB2315860A - Remote control receiver with noise filter

Info

Publication number: GB2315860A
Application number: GB9715648A
Authority: GB
Inventors: Kwon Jeong
Original assignee: LG Electro Components Ltd
Current assignee: LG Innotek Co Ltd
Priority date: 1996-07-26
Filing date: 1997-07-24
Publication date: 1998-02-11
Also published as: JPH10242488A; GB9715648D0; KR980010014U; DE19732110A1

Abstract

A remote control receiver (110) has a light noise cutoff filter (120) for smoothly filtering external light (100) whilst allowing infrared rays (192) to reach a receiving unit (130). The filter has a plurality of cutoff holes (124) piercing a screen from the front to the back thereof. wherein, in an up-and-down direction, the angle of inclination of each cutoff hole becomes greater the nearer the cutoff hole is arranged to the upper side of the receiver and, in a left-and right direction, the angle of inclination becomes greater the further the cutoff hole is arranged from the centre towards either side.

Description

2315860 LIGHT NOISE CUTOFF FILTER OF REMOTE CONTROL RECEIVER The present

invention relates to a light noise cutoff filter of a remote control receiver, and in particular an improved a light noise cutoff filter capable of smoothly filtering external light, allowing infi-ared rays radiated from an infrared remote control to penetrate whilst cutting off external light noise thereby preventing erroneous operation of a remote control system.

Two known constructions for an infi-ared remote control receiver are shown in Figures 1 A and 1 B, one with a light noise cutoff filter 20 internally fixed therein, as shown in Figure 1 A, and another with a light noise cutoff filter 21 externally fixed, as shown in Figure 1 B. Since these two receivers have the same construction and operation except for the configuration of the filter, the construction and operation of the conventional remote control receiver shown in Figure 1 A will be described.

In the conventional infi-ared remote control receiver 10, the cutoff filter 20 is internally fixed with a front face of a cuboid or hexahedral casing 50 of which an upper part of the front face is open. Inside the casing 50, a panel 70 is substantially centrally installed by connecting a predetermined area of a top wall of the casing 50 and a predetermined area of a bottom wall of the casing 50. A receiving unit 30 and an amplification unit 40 which are spaced from each other are installed on a surface of the panel 70 facing forward to the front wall of the casing 50. In this case, the receiving unit 30 is located above the amplification unit 40.

The cutoff filter 20 comprises a frame 20a and a plurality of inclined plates 20b. The frame 20a acts as the main body of the cutoff filter 20, and the plurality of inclined plates 20b, having a same angle and spaced apart from each other by a predetermined distance, are formed in the surface of the frame 20a so as to face the inside of the casing 50.

However. as shown in Figures I B and I C, in the externally fixed light noise cutoff filter 2 1.

the cutoff filter 21 is externally fixed on the front face of a cuboid or hexahedral casing 50 of which an upper part of the front face is open, and a plurality of inclined plates 21 b thereof, having a same angle and a certain distance each other. are formed in the surface of the frame 2 1 a facing the outside of the casing 5 0.

The operation of the conventional infrared remote control receiver will now be described.

As shown in Figure I A, when infrared rays 92 are radiated from an infrared remote control 90 and are incident on the front face of the infrared remote control receiver 10, the receiving unit 30 receives the infrared rays 92 and converts the received signal to an electric signal which is transferred to the amplification unit 40 where it is amplified and outputted. Light noise radiated from an external light such as a fluorescent lamp is cut off by the cutoff filter 20. In particular, the external light noise is cut off by the plurality of inclined plates 20b forming opaque webs each inclined at the same angle and formed in the frame 20a of the cutoff filter 20.

In this conventional remote control receiver, however, when the inclined plates of the cutoff filter are deflected or damaged by careless handling by the user, the cutoff filter cannot function properly.

In addition, infrared rays generated from an infrared remote control transmitter are interfered with by an external light which has specific illumination, such as an inverter fluorescent lamp or a neon sign, or a specific location, whereby the infrared rays cannot be transmitted to the receiving unit and erroneous operation of the system may occur.

It is an object of the present invention to provide a light noise cutoff filter of a remote control receiver enabling infrared rays radiated from an infrared remote control transmitter and transmitted to a receiving unit to be received largely without interference from external light sources, whereby the remote control can operate accurately.

According to the invention, there is provided a light noise cutoff filter of a remote control receiver which is fixed with a front face of a casing of the remote control receiver for receiving infrared rays radiated from an infrared remote control and converting the infrared to an electric signal and, in order to make the infrared rays penetrate, and absorb and cut off a light noise radiated from an external light, a plurality of cutoff holes are formed therein piercing from the front to the back thereof, wherein, in an up-and-down direction, an angle of inclination of each cutoff hole becomes greater as the cutoff hole is arranged from a down side to an up side and, in a left-and-right direction, an angle of inclination becomes greater as the cutoff hole is arranged from a centre to both end sides.

The invention will now be described by way of example with reference to the drawings in which:

Figure I A is a cross-sectional view of a remote control receiver provided with a conventional internally fixed light noise cutoff filter; Figure I B is a cross-sectional view of a remote control receiver provided with a conventional externally fixed light noise cutoff filter; Figure I C is a perspective view of the conventional externally fixed light noise cutoff filter; 25 Figure 2 is a cross-sectional view illustrating a light noise cutoff filter in accordance with the present invention, installed in a remote control receiver; Figure 3A is a front view of the cutoff filter of Figure 2; 4 Figure 3B is a cross-sectional view taken along the line lIIb_IlIb of Figure 3A, and Figure 3C is a cross-sectional view taken along the line III,,-III, of Figure 3A..

Referring to Figure 2, the construction of the illustrated remote control receiver I 10 is the same as that of the conventional one of Figures I A and I B except for that of a cutoff filter for cutting off external light noise.

The cutoff filter 120 of the receiver 110 is internally fixed in the front wall of a casing 150 of the receiver I 10 for receiving infrared rays radiated from an infrared remote control transmitter 190 and converting the infrared radiation to an electric signal. The filter 120 comprises a screen having a plurality of cutoff holes 124 passing from a front face to the back face of the screen. In this embodiment, as shown in Figure 3A, the cutoff holes 124 are arranged in a matrix having three holes vertically and horizontally, respectively, and there are nine holes in total. Each of the cutoff holes 124 has the same diameter and they are equally spaced from each other.

As shown in Figures 3B and _3)C, in an up-and-down direction, the angle of inclination a,, e, of the cutoff holes with respect to an axis perpendicular to the front face of the receiver becomes greater as the distance from a lower side of the screen increases and the distance to an upper side of the screen decreases. In a left-and-right direction, the angle of inclination 03 of the cutoff holes with respect to the axis becomes greater as the distance of the cutoff hole from the centre of the matrix increases, and the distance to either lateral side decreases.

In the other embodiments in accordance with the invention, the number of the cutoff holes does not have to be nine and, also, the spacing between the cutoff holes need not be uniform.

Since the light noise cutoff filter used for the remote control receiver of Figures 2 and 3A to 3 C has cutoff holes 124 with predetermined angles of inclination 6 1, 0,, and03 in the up-and- down and left-and-right directions respectively. an inclined direction of the cutoff holes 124 is towards a larger area and external light noise 100 is filtered by the cutoff holes 124 and is not able to reach a receiving unit 1330 fixed on a panel 170 inside the casing 150. whereby erroneous operation of the remote control system caused by the light noise 100 is prevented.

Instead, the external light noise 100 is absorbed and cut off by the cutoff filter 120 and infrared rays 192 radiated from a remote control 190 penetrate the cutoff filter 120 and reach the receiving unit 130.

After converting the received signal to an electric signal, the receiving unit 130 transfers the electric signal to an amplification unit 140 and the amplification unit 140 amplifies and outputs a signal for operating and controlling an appliance such as a TV, VCR, etc The light noise cutoff filter of the remote control receiver as described above when installed in remote-controlled electronic equipment has a plurality of cutoff holes having respectively different angles of inclination in the up-and-down and left-and-right direction. Accordingly, although an external light source may be in any position, the light cutoff filter is not interfered with the external light and able to receive only the desired infrared rays, thereby preventing the infrared remote control receiver from operating erroneously, and thereby improving reliability and quality.

-)0 Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as recited in the accompanying claims.

6

Claims

1. A light noise cutoff filter of a remote controi receiver which is fixed with a front face of a casing of the remote control receiver for receiving infrared rays radiated from an infrared remote control and converting the infrared rays to an electric sign4 the filter comprising a plurality of cutoff holes piercing from the front to the back thereof, wherein, in an up-and-down direction, an angle of inclination of each cutoff hole becomes greater as the cutoff hole is arranged from a down side to an up side and, in a left-and-right direction, an angle of inclination becomes greater as the cutoff hole is arranged from a centre to both end sides, in order that the infrared rays penetrate the filter whereas light noise radiated from an external light source is absorbed and cut o ff.

2. A filter according to claim 1, wherein the number of cutoff holes is the same in the vertical direction as in the horizontal direction.

3. A remote control receiver unit for mounting in remotely controllable electrical equipment and for receiving control radiation from a remote control transmitter, wherein the receiver unit has an internal transducer for converting the control radiation into an electrical control signal and a filter screen with an array of through bores centred on respective axes which converge in the direction from the outside to the inside of the unit.

4. A remote control receiver unit according to claim 3, wherein the through bores are distributed over an area and their central axes converge inwardly in orthogonal planes.

5. A remote control receiver unit constructed and arranged substantially as herein described and shown in Figures 2 and 3 A to 3C of the drawings.