A collision-prediction unit for a vehicle including a road condition detector, a maximum deceleration estimator, a forward vehicle detector, a forward vehicle deceleration calculator, and a collision examiner is provided. The first end can connect to the audiovisual device, whereas the second end can connect to the device. In the reference channel containing signal delay means, a reference echo is processed to obtain temperature compensation information. One embodiment provides a method of fabricating a cathode, which reduces the unit cost of thin CRTs. The tartrates may be selected from the group which may include solium acid tartrate, potassium acid tartrate, potassium sodium tartrate tetrahydrate and sodium tartrate dihydrate, but are not limited thereto.