It requires about 10 minutes

there is a reading lens in the unit.its called the "EYE" of the unit.if the reading lens is weak and dusty.this problem occurs.because the reading lens is weak it takes time to show up the picture and because its dusty it shows fuzzy picture. the internal lens first has to be cleaned and checked.if still the same problem the lens has to be replaced.this is common problem faced by many users.but replacing the lens solves the problem.for getting it replaced you can take it to the local electronics repair center.this will help. thanks.please do rate the solution.thank you for using fixya.