Digital indication type speedometer
US4368426A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1980 |
| Grant date | Jan 11, 1983 |
| Priority date | — |
| Expiry date | Dec 22, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/489
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A digital indication type speedometer comprising a speed counter for counting speed pulses emitted in proportion to a vehicle speed for a given gate time, an indication resistor for latching a value to be indicated commensurate to an output from said speed counter and an indicator for indicating the value latched in said indication register is of such an arrangement that a zero indication discriminating circuit for forcibly setting the value latched in said indication register to zero when an emitting interval of the speed pulses exceeds a predetermined period of time, is provided with or without a hysteresis processing circuit for rewriting the value latched in said indication register in accordance with an output of said speed counter only when a difference between the output of said speed counter and the value latched in said indication register is not within tolerance limit upon comparison therebetween, so that the indication is momentarily returned to zero when the vehicle is stopped, the indication is changed in a short period of time in accordance with the condition of acceleration or deceleration during acceleration or deceleration of the vehicle and no flickering of the in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.