Vibrating device and image equipment having the same

An image equipment comprising:

• an image forming element having an image surface on which an optical image is formed;
• a dust-screening member shaped like a plate as a whole, having front and back surfaces and having light-transmitting region for transmitting light between the front surface and the back surface;
• a support member configured to support the dust-screening member, to space the light-transmitting region of the dust-screening member, apart from the image surface of the image forming element by a predetermined distance, and to render the back surface of the dust-screening member airtight;
• a first vibrating member shaped almost like a rectangle, arranged at a first outer circumferential part of the dust-screening member and composed of a vibration application part and a non-vibration application part;
• a second vibrating member shaped almost like a rectangle, arranged at a second outer circumferential part of the dust-screening member, which opposes the first outer circumferential part of the dust-screening member, and composed of a vibration application part and a non-vibration application part;
• and
• a drive unit configured to input an electrical signal to the first and second vibrating members to generate, in the light-transmitting region of the dust-screening member, vibration forming peak ridges defining a closed curve around a first virtual intersection of an virtual symmetry axis at the same distance from the first and second vibrating members and a vibrational axis for both first and second vibrating members, the vibration gradually increasing as the amplitude of each vibrational peak approaches the first virtual intersection, and having a maximum amplitude at the vibrational peak including the first virtual intersection,
• wherein the drive unit is configured to control the electrical signal input to the first and second vibrating members, thereby to move the vibrational axes of the first and second vibrating members on the virtual symmetry axis and to change the first virtual intersection to a second virtual intersection and moving a vibrational peak of maximum vibrational amplitude to a position including the second virtual intersection.