Myles Anthony Hall, 62, had taken his parents to Morecambe for the day on June 5 when he was stopped at 1pm by police because of a faulty brake light, the court was told.
Officers smelt alcohol on his breath, a roadside breath test was positive and he was taken to the police station where he was found to have 51 microgrammes of alcohol in 100 millilitres of breath. The legal limit is 35.
Hall, who admitted drink-driving, lived with his parents and was a full-time carer for his 88-year-old mother, the court was told in mitigation.
Keith Blackwell said Hall, of Hillworth Close, Oakworth, also took care of his father and had been taking them out for the day when he was stopped because of a faulty light.
He had no previous convictions and had co-operated fully with the police.
Hall was banned from driving for 12 months, fined £110 and ordered to pay costs of £85 and a victims surcharge of £20.
If he completes a drink drivers rehabilitation course, his ban will be reduced by a quarter.