Warning device for cameras

摘要

A warning device to be incorporated for giving a warning or attention-getting statement in synthesized human speech to call the attention of a photographer to the need to correct the condition of the camera. The warning device includes a power supply which is adapted to operate upon receiving a warning signal provided corresponding to the occurrence of a camera condition to be warned against and a delay circuit for delaying the warning signal. The power supply is adapted to allow the power supply to an amplifier connected between an acoustic signal generating circuit and a speaker immediately upon receiving the warning signal. The delay circuit directs the warning signal to the acoustic signal generating circuit with a certain delay time at least equal to the time in which the amplifier becomes stable in its operational state for the successful synthesis of acoustic signals. Thus, the amplifier is powered only during the period of delay plus the period of the synthesized speech, thereby to conserve the power of a battery while at the same time ensuring that the beginning of the synthesized speech will be audible.