Illuminating system with discharge lamp and method for preventing any toxic gases and/or broken glass debris from breaking out of the illuminating system

The present invention is an illuminating system with a discharging lamp (especially a high-voltage discharging lamp), which is installed in an air-tight isolated apparatus. In accordance with the method of the present invention, a safety valve is equipped in the isolated apparatus. When the air inside the internal cavity of the isolated apparatus expands due to the heat generated after the discharging lamp is turned on, the air will be exhausted out of the isolated apparatus through the safety valve. In case the discharging lamp explodes, the illuminating system can prevent any toxic gases (especially mercury steam) generated by the mercury high-voltage discharging lamp from leaking out of the illuminating system to its surroundings. Besides, the present invention also presents a method for preventing any toxic gases and/or broken glass debris from breaking out of an illuminating system, having a discharging lamp installed inside an air-tight isolated apparatus, when the discharging explodes. By applying some suitable means, the method allows a specific pressure relation to form between the internal cavity and the external of the isolated apparatus. Such pressure relation will prevent any toxic gases and/or broken glass debris from breaking out of the isolated apparatus in case the discharging lamp explodes.