Image reading device and image forming apparatus incorporating same

An image reading device comprising:

• a background member;
• an illumination unit opposed to the background member, the illumination unit configured to emit light to a recording medium having an image thereon;
• a reader configured to receive a reflection from the recording medium to read the image,
• the background member having a facing surface configured to face the recording medium, the facing surface including a reference portion on a predetermined portion, the reference portion having a higher reflectance than a portion different from the predetermined portion on the facing surface in a width direction of the background member, and the facing surface providing a minimum passage area in the width direction on which the recording medium having a minimum width passes through;
• and
• a support contacting an end of the background member in the width direction to support the background member, wherein the support includes another reference portion having a higher reflectance than the portion different from the predetermined portion.

An image reading device comprising:

• a background member;
• an illumination unit opposed to the background member, the illumination unit configured to emit light to a recording medium having an image thereon;
• a reader configured to receive a reflection from the recording medium to read the image;
• the background member having a facing surface configured to face the recording medium;
• and
• a reference member that is separate from the background member and located outside the facing surface in the width direction, the reference member having a higher reflectance than the facing surface of the background member in the width direction.