PROJECTION TYPE DISPLAY DEVICE

PROBLEM TO BE SOLVED: To provide a projection type display device constituted so that the mounting space of electronic parts on a control circuit board can be widened. SOLUTION: This projection type display device is constituted so that the control circuit board 100 loading a control circuit which can control the driving of respective equipments in the device by an operation signal inputted from an external light receiving unit is housed in a prescribed space in a device case 10 and provided with a signal transmission means consisting of a light emitting element 175 and a photodetector 176 at a conductive path formed on the circuit board as the path for transmitting the signal inputted from the outside of the control circuit. The board 100 is constituted of a first circuit board (a main circuit board 100A and an audio circuit board 100B) loading the control circuit and a second circuit board (a video circuit board 100C) which is opposed to the first circuit board and to which the operation signal is inputted from the external light receiving unit. Besides, the first circuit board is provided with the element 175 and the second circuit board is provided with the photodetector 176. Thus, since the mounting space of the electronic parts is widened, the high-density mounting of the electronic parts is realized and the device can be made compact.