WO2008122090A1

WO2008122090A1 - Device for detecting image signal transmissions

Info

Publication number: WO2008122090A1
Application number: PCT/AU2008/000499
Authority: WO
Inventors: Dev Kumar
Original assignee: The Noise Company Pty Ltd
Priority date: 2007-04-10
Filing date: 2008-04-07
Publication date: 2008-10-16

Abstract

A signal detection device (10) comprising a receiving means for receiving transmissions within at least one frequency band in which image information is transmitted and an alert means for providing an indication that a transmission within the or each frequency band has been detected. The frequency band is divided into a plurality of sub-bands and the receiving means scans each of the sub-bands for transmissions. The receiving means also scans for transmissions at one or more predefined frequencies.

Description

Device for detecting image signal transmissions

Field of the Invention

The present invention relates to a device for detecting signals, particularly signals associated with the transmission of image information.

Background to the Invention

Small wireless cameras are becoming increasingly more affordable and available to the general public. Such cameras, while having many legitimate uses, can be used to take pictures of people without their knowledge or consent. There is therefore a demand for devices that people can use to detect whether such a camera may be in operation in their vicinity.

Such detection devices are available however have a number of limitations, including the range over which they can detect the operation of a camera transmitting images wirelessly.

Summary of the Invention

According to one aspect of the present invention there is provided a signal detection device comprising: a receiving means for receiving transmissions within at least one frequency band in which image information is transmitted; and an alert means for providing an indication that a transmission within said frequency band has been detected; wherein said frequency band is divided into a plurality of sub-bands and the receiving means scans each of the sub-bands for transmissions also scans for transmissions at one or more predefined frequencies.

Preferably the signal detection device includes a first mode of operation in which each of the sub-bands are scanned in turn for transmissions. The signal detection device also preferably includes a second mode of operation in which the one or more predefined frequencies are scanned for transmissions. The signal detection device may alternate between the first and second modes of operation in use.

Preferably the frequency bands include 1.2GHz and 2.4GHz bands. Preferably the sub-bands comprise 50Hz bands within these frequency bands.

In a preferred embodiment, the signal detection device is provided in a portable housing. The visible alert may comprise one or more lights on the housing which are illuminated when a signal is detected. The alert means may include a visible alert.

Preferably a means is provided to indicate the strength of the signal detected. The means to indicate signal strength preferably comprises varying the characteristics of the alerts provided by the alert means. The number of times a visible alert flashes or the speed of the flashing may varied according to signal strength. The number of beeps emitted or pitch of beeps may also be varied according with signal strength.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the working of the invention.

Brief Description of the Drawings

The nature of the invention will be better understood from the following detailed description of one embodiment of the signal detection device, given by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is view of a signal detection device in accordance with the present invention.

Detailed Description of the Preferred Embodiment

A preferred embodiment of a signal detection device 10 in accordance with the present invention will now be described.

The signal detection device 10 comprises a portable housing 12 for detecting signals, primarily signals which would indicate the possible transmission of image information in the vicinity of the signal detection device 10.

The housing 12 is preferably small enough to be easily carried, such as in the pocket or bag or a person, or attached to a key-ring. The housing 12 includes a receiving means in the form of suitable electronic circuitry having a battery power supply. The receiving means includes an RF receiver able to detect transmissions in one or more predefined frequency bands. The predefined frequency bands include the 2.4GHz band and 1.2 GHz bands. These bands are commonly used for the transmission of pictures from wireless camera devices.

The signal detection device 10 includes an alert means provided to alert the user of the signal detection device 10 that the receiving means has detected transmission of signals in the 2.4GHz or 1.2GHz bands. The alert means may comprise any suitable means but preferably includes a visible alert in the form of one or more lights 14 on the housing 12 and an audible alert in the form of a speaker arranged to emit a beeping noise.

The frequency bands in which the signal detection device 10 detects signals are divided into a plurality of sub-bands. The signal detection device 10 scans each of these sub-bands individually for transmissions. The frequency bands are typically divided into 50Hz sub-bands. Preferably the signal detection device includes a first mode of operation in which the signal detection device 10 alternately scans each of the 50 Hz sub-bands.

The signal detection device 10 also scans one or more predefined frequencies, corresponding to the frequencies of transmission of known wireless camera devices. Preferably the signal detection device 10 includes a second mode of operation in which each of the predefined frequencies are alternately scanned. The signal detection device 10 would, in use, typically operate alternately in the first and second modes of operation.

The use of the first and second modes of operation allows the signal detection device to increase the range over which signal sources can be detected.

The housing 12 includes an activation button 16, such that depression of the activation button turns the device on and further depression turns the device off. Preferably the signal detection device 10 will turn itself off after a predetermined time period to conserve battery power.

The housing 12 also includes a means to switch the signal detection device between the audible alert mode and the visible alert mode. The means may be by further depression of the activation button 16 once the signal detection device is on.

Preferably, the alert means includes a means to indicate the signal strength of a detected signal. The means to indicate the signal strength may be via varying the characteristics of the alerts provided by the alert means. In the case of a visible alert means, the alert means may flash a number of times related to how close the signal source is to the signal detection device. An audible alert means may beep a number of times related to how close the signal source is to the signal detection device. Other methods may be used such as the colour of the visible alert means or the pitch of the audible alert means changing relative to the signal strength received. The signal detection device can thereby be used to locate the source of the signal by moving the signal detection device and monitoring the alert means.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention.

Claims

1. A signal detection device comprising: a receiving means for receiving transmissions within at least one frequency band in which image information is transmitted; and an alert means for providing an indication that a transmission within the or each frequency band has been detected; wherein said frequency band is divided into a plurality of sub-bands and the receiving means scans each of the sub-bands for transmissions also scans for transmissions at one or more predefined frequencies.

2. A signal detection device in accordance with claim 1 , wherein the signal detection device includes a first mode of operation in which each of the sub-bands are scanned alternately.

3. A signal detection device in accordance with claim 2, wherein the signal detection device includes a second mode of operation in which the one or more predefined frequencies are scanned alternately for transmissions.

4. A signal detection device in accordance with claim 3, wherein the signal detection device alternates between the first and second modes of operation in use.

5. A signal detection device in accordance any one of the preceding claims, wherein the frequency bands include 1.2GHz and 2.4GHz bands.

6. A signal detection device in accordance with any one of the preceding claims, wherein the sub-bands comprise 50Hz bands within the frequency bands.

7. A signal detection device in accordance with any one of the preceding claims, wherein the signal detection device is provided with a portable housing.

8. A signal detection device in accordance with any one of the preceding claims, wherein the alert means includes a visible alert.

9. A signal detection device in accordance with claim 8, wherein the visible alert comprises one or more lights on the housing which are illuminated when a signal is detected.

10. A signal detection device in accordance with any one of the preceding claims, wherein the alert means includes an audible alert.

11. A signal detection device in accordance with any one of claims 7 to 10, wherein an activation button is provided on the housing such that depression of the activation button changes the signal detection device between an on mode and an off mode.

12. A signal detection device in accordance with any one of the preceding claims, wherein a means is provided to indicate the strength of the signal detected.

13. A signal detection device in accordance with claim 12, wherein the means to indicate signal strength comprises varying the characteristics of the alerts provided by the alert means.

14. A signal detection device in accordance with claim 13, wherein the number of times a visible alert flashes or the speed of the flashing is varied according to signal strength.

15. A signal detection device in accordance with claim 13, wherein the number of beeps emitted or pitch of beeps is varied according with signal strength.