The present invention discloses a light-emitting diode lamp for connecting to an external current source. The LED lamp comprises: a lighting source comprising a plurality of LEDs; a power control module for connecting in parallel to the external current source; and a driver unit connected between the power control module and the lighting source, wherein the power control module is configured to transform a source voltage of the external current source to a desired load voltage based on output power requirement of the plurality of LEDs; and the driver unit is configured to rectify the desired load voltage and output a driving voltage to drive the plurality of LEDs. Without the need to modify a lamp base of a conventional High Intensity Discharge lamp, the LED lamp of the present invention can be directly used to replace the HID lamp. Moreover, the power control module of the present invention ensures that LED lamps of different power have consistent shapes and dimensions, thus enhancing the versatility of components of the LED lamp and reducing the production costs.

A projector which configured to project a horizontally long image and a vertically long image, includes a cooling unit configured to cool a discharge lamp according to an installation attitude of the projector, a detection unit configured to detect the installation attitude, and a controller configured to control a discharge lamp driving unit and the cooling unit, in which the installation attitude includes a first attitude for projecting the horizontally long image and a second attitude for projecting the vertically long image, and in which the controller is configured to put out the discharge lamp in a case where the installation attitude detected by the detection unit is a third attitude which is different from both of the first attitude and the second attitude.

A projector which configured to project a horizontally long image and a vertically long image, includes a cooling unit configured to cool a discharge lamp according to an installation attitude of the projector, a detection unit configured to detect the installation attitude, and a controller configured to control a discharge lamp driving unit and the cooling unit, in which the installation attitude includes a first attitude for projecting the horizontally long image and a second attitude for projecting the vertically long image, and in which the controller is configured to put out the discharge lamp in a case where the installation attitude detected by the detection unit is a third attitude which is different from both of the first attitude and the second attitude.