Patent ID: 6708115
Filing Date: 2004-03-16
Classification: G01C

Abstract:
A speedometer for a vehicle, comprising:first storage means in which travelling distance data per unit pulse of a vehicle speed pulse signal outputted from a vehicle speed sensor is pre-stored, correction means including a navigation device for correcting travelling distance per unit pulse outputted from the vehicle speed sensor; second storage means for storing the corrected travelling distance data per unit pulse inputted from the correction means; computation means for computing: at least one of the vehicle speed and the travelling distance on the basis of the travelling distance data per unit pulse that is pre-stored in the first storage means, in a state in which the correction means cannot correct travelling distance data per unit pulse and the corrected traveling distance data per unit pulse is not stored in the second storage means; at least one of the vehicle speed and the travelling distance on the basis of the corrected travelling distance data per unit pulse, that is stored in the second storage means, in a state in which the correction means cannot correct travelling distance data per unit pulse and the corrected travelling distance data per unit pulse is stored in the second storage means; and at least one of the vehicle speed and the travelling distance on the basis of the corrected travelling distance data per unit pulse, in a state in which the correction means can correct travelling distance data per unit pulse, and switching means for conducting data from one of said first or second storage to said computation means.