Droplet ejection apparatus

A droplet ejection apparatus, comprising:

• a platen on which an ejection target medium is conveyed;
• a head that ejects droplets toward the platen, the head being provided in a reciprocal manner along the platen;
• a light emitting device that emits a light in an oblique direction toward the platen within a plane including a straight line along a moving direction of the head and a normal line with respect to the platen;
• a light receiving device that receives the light emitted from the light emitting device and regularly reflected by one of the platen and the ejection target medium;
• and
• a calculation device that calculates a distance between the one of the platen and the ejection target medium, and the head, based on a position at which the light receiving device receives the light during a movement of the head,
• one of the light emitting device and the light receiving device being adapted to reciprocably move integrally with the head, and the other one of the light emitting device and the light receiving device being provided separately from the head, further comprising:
• a setting device that sets a type of the ejection target medium;
• an adjusting device that adjusts the distance between the platen and the head in accordance with the type of the ejection target medium set by the setting device;
• and
• a distance determination device that determines whether or not the distance between the platen and the head calculated by the calculation device is consistent with a distance corresponding to the type of the ejection target medium.

An image recording apparatus for recording an image by ejecting droplets onto a recording medium, comprising:

• a conveying mechanism that conveys the recording medium;
• a platen on which the recording medium is conveyed by the conveying mechanism;
• a head that ejects droplets toward the platen, the head being provided in a reciprocal manner along the platen;
• a light emitting device that emits a light in an oblique direction toward the platen within a plane including a straight line along a moving direction of the head and a normal line with respect to the platen;
• a light receiving device that receives the light emitted from the light emitting device and regularly reflected by one of the platen and the recording medium;
• and
• a calculation device that calculates a distance between the one of the platen and the recording medium, and the head, based on a position of the head at which the light receiving device receives the light during a movement of the head,
• one of the light emitting device and the light receiving device being adapted to reciprocably move integrally with the head, and
• the other one of the light emitting device and the light receiving device being provided separately from the head, such that the one device moves towards or away from the other device as the head is provided in a reciprocal manner along the platen.

An image recording apparatus for recording an image by ejecting droplets onto a recording medium, comprising:

• a conveying mechanism that conveys the recording medium;
• a platen on which the recording medium is conveyed by the conveying mechanism;
• a head that ejects droplets toward the platen, the head being provided in a reciprocal manner along the platen;
• a light emitting device that emits a light in an oblique direction toward the platen within a plane including a straight line along a moving direction of the head and a normal line with respect to the platen;
• a light receiving device that receives the light emitted from the light emitting device and regularly reflected by one of the platen and the recording medium;
• and
• a calculation device that calculates a distance between the one of the platen and the recording medium, and the head, based on a position at which the light receiving device receives the light during a movement of the head,
• one of the light emitting device and the light receiving device being adapted to reciprocably move integrally with the head, and
• the other one of the light emitting device and the light receiving device being provided separately from the head, further comprising:
• a setting device that sets a type of the recording medium;
• an adjusting device that adjusts the distance between the platen and the head in accordance with the type of the recording medium set by the setting device;
• and
• a distance determination device that determines whether or not the distance between the platen and the head calculated by the calculation device is consistent with a distance corresponding to the type of the recording medium.