Wet-type image forming apparatus

A wet-type image forming apparatus comprising:

• an image carrier;
• a toner developer layer formed of toner and a carrier liquid carried on said image carrier;
• and
• a toner amount detection unit for detecting a toner amount of the toner developer layer carried on said image carrier,
• said toner amount detection unit including:
• a light-emitting unit for emitting light to the toner developer layer carried on said image carrier and
• a light-receiving unit for receiving reflected light when light is emitted from said light-emitting unit to the toner developer layer carried on said image carrier,
• wherein wavelength characteristics of a light emission intensity of said light-emitting unit and a light reception sensitivity of said light-receiving unit are set such that an intensity of detection sensitivity of said toner amount detection unit in accordance with a product of a light emission intensity of said light-emitting unit and a light reception sensitivity of said light-receiving unit is greater in a wavelength region in which a characteristic value based on a product of a transmittance of the toner developer layer and a reflectivity of said image carrier as a reference for a light emission wavelength is included in a predetermined range, than in other wavelength regions.