Image reading device, image reading method, and computer-readable medium

An image reading method comprising:

• detecting reflected light generated by a subject reflecting light emitted from a light source configured to irradiate the subject with light, to perform reading;
• performing turn-on control to change a turn-on condition such that the light source is turned on during a first period when at least a detection region including an image pattern on the subject passes through a reading position in the reading and the light source is turned off or turned on with a light amount lower than a light amount of the first period during a second period when a region other than the detection region passes through the reading position in the reading, based on position information of an image pattern of the subject stored in a memory in a first operation mode for reading the subject;
• and
• performing turn-on control to make the turn-on condition of the light source constant during a third period when the subject passes through the reading position in the reading regardless of the image pattern of the subject passing through the reading position in the reading in a second operation mode for reading the subject.

A non-transitory computer-readable medium including programmed instructions that cause a computer to perform:

• causing a reader to detect reflected light generated by a subject reflecting light emitted from a light source configured to irradiate the subject with light, to perform reading;
• performing turn-on control to change a turn-on condition such that the light source is turned on during a first period when at least a detection region including an image pattern on the subject passes through a reading position in the reading and the light source is turned off or turned on with a light amount lower than a light amount of the first period during a second period when a region other than the detection region passes through the reading position in the reading, based on position information of an image pattern of the subject stored in a memory in a first operation mode for reading the subject;
• and
• performing turn-on control to make the turn-on condition of the light source constant during a third period when the subject passes through the reading position in the reading regardless of the image pattern of the subject passing through the reading position in the reading in a second operation mode for reading the subject.