PURPOSE: To read out precisely also the contents of a tag covered with a transparent sheet which is easily wrinkled or distorted and having high reflection factor by forming a reflection part, reflection surface and a difussion wall on the inside of a lamp.

CONSTITUTION: The lamp 4 held by a holder 2 is stored in a lamp storing room and arranged close to the reflection surface 21 side from the diffusion wall 20 and its reflecting surface is formed like a curve arranging the lamp 4 on its focus. The reflection part 22 is formed inside the lamp so as to be opposed to the diffusion wall 20 and the most of the light from the lamp 4 is reflected by the reflection surface 21, diffused by the diffusion wall 20 and irradiated to the recording surface 9 through an opening part 15. A part of the light from the lamp 4 is transmitted through the wall 20 from both the sides of the reflection part 22 and irradiated to the surface 9 and the irradiated light is reflected on the surface 9. A photodetecting element 7 decides black or white in accordance with the level of the reflected light. Thus, also the contents of the tag covered with the transparent sheet are read assuredly by providing the reflection part 22.