Image diagnostic method, image diagnostic device, and image forming apparatus

An image diagnostic method executed by an image diagnostic device for an image formed by an image forming apparatus including:

• an image forming engine;
• and
• a reader that is disposed along a conveyance path of a medium and reads the medium downstream of an image formation site of the image forming engine on the conveyance path,
• the image diagnostic method comprising:
• adjusting an image formation position;
• and,
• after the adjusting has been executed, diagnosing a state of the image forming engine, wherein
• the adjusting includes:
• causing the image forming engine to form a first pattern for adjusting the image formation position;
• causing the reader to read a first medium on which the first pattern has been formed;
• and
• adjusting the image formation position based on a reading result of the first medium, and
• the diagnosing includes:
• causing the image forming engine to form a second pattern for diagnosing the state of the image forming engine;
• causing the reader to read a second medium on which the second pattern has been formed;
• and
• acquiring a diagnosis result of the state of the image forming engine based on a reading result of the second medium.