Inkjet image forming apparatus

An inkjet image forming apparatus comprising:

• an image forming part which ejects ink on a printing base material conveyed in a predetermined conveyance direction to form an image;
• a precoating unit which is arranged on an upstream side of the image forming part in the conveyance direction, and ejects a precoating liquid having a property of absorbing UV light;
• a fluorescent coating surface which is arranged between the image forming part and the precoating unit, and on which the printing base material is conveyed;
• and
• a UV lighting device which irradiates the printing base material conveyed on the fluorescent coating surface with UV light;
• a camera which photographs the printing base material irradiated with the UV light, wherein
• a position adjustment mark is formed on the printing base material by using the precoating liquid in the precoating unit, the formed position adjustment mark is irradiated with the UV light by the UV lighting device, the irradiated position adjustment mark is photographed by the camera, and the image forming part forms an image based on the photographed position adjustment mark.