TOKYO, Nov 28 (Reuters) - A Japanese court ruled on Thursday that the government's refusal to accept votes written on behalf of physically disabled patients who cannot write on their own violated their voting rights and was unconstitutional.

But the Tokyo District Court rejected the damages suit filed by patients suffering from Lou Gehrig's disease seeking compensation from the government, saying lawmakers could not be held accountable for not taking steps to correct the situation.

"The absence of an election system where patients can exercise their voting rights is unconstitutional," presiding judge Takahisa Fukuda said.

But he absolved parliament of blame, saying that lawmakers in general were not aware of the unconstitutional situation.

The two patients of the disease, amyotrophic lateral sclerosis (ALS), and the husband of another patient had sought a total of 2.7 million yen ($22,060) in compensation from the government, Kyodo news agency said.

Following the ruling, the government said it would look into measures to ensure voting rights for the disabled.

"It's necessary to make it so that any person in any situation is able to vote...We would like to consider what steps to take," Chief Cabinet Secretary Yasuo Fukuda told a news conference.

Japanese electoral laws allow people with severe physical disabilities to mail in their votes, but requires them to write their signatures, making it impossible for ALS patients to cast their ballots.

ALS is a degenerative motor neuron disease that attacks nerve cells in the brain and spinal cord, causing patients to lose control of muscle movement and become paralysed.

It often strikes people in their fifties and kills half its victims within three years, usually from respiratory failure. It cut short the life of the legendary U.S. baseball player Lou Gehrig, hence the popular name for the disease.

According to the Japan Amyotrophic Lateral Sclerosis Association, there are about 6,200 ALS patients nationwide, of whom 2,000 to 3,000 depend on artificial respirators and receive care at home, Kyodo said.

($1=122.36 Yen)