Image formation apparatus and image formation method

1 . An image formation apparatus comprising:

a storage storing a decorative medium printing program;

a non-lustrous image formation unit configured to form a non-lustrous image of a non-lustrous developer;

a lustrous image formation unit configured to form a lustrous image of a lustrous developer comprising metallic pigment;

a conveyance path that extends from a medium feeder to a discharge port through a transfer part at which the non-lustrous image and the lustrous image are transferred to a transparent medium;

a reconveyance mechanism including a reconveyance path and configured to return the transparent medium from downstream to upstream of the transfer part with the transparent medium being flipped over; and

a controller configured to control, based on printing data, the non-lustrous image formation unit, the lustrous image formation unit, and the reconveyance mechanism, wherein

the decorative medium printing program controls, when executed by the controller, (i) the non-lustrous image formation unit to form the non-lustrous image on a first surface of the transparent medium, the reconveyance mechanism to return the transparent medium from downstream to upstream of the transfer part with the transparent medium being flipped over, and the lustrous image formation unit to form the lustrous image including a first region and a second region on a second surface, which is an opposite surface of the first surface, or (ii) the lustrous image formation unit to form the lustrous image including the first region and the second region on the second surface, the reconveyance mechanism to return the transparent medium from downstream to upstream of the transfer part with the transparent medium being flipped over, and the non-lustrous image formation unit to form the non-lustrous image on the first surface of the transparent medium, thereby obtaining the transparent medium that comprises the non-lustrous image on the first surface and the lustrous image on the first region and the second region of the second surface, such that a difference between a first adhesion ratio and a second adhesion ratio is 18.75% or more and 37.50% or less, where the first adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the first region of the second surface, and the second adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the second region of the second surface.

2 . The image formation apparatus according to claim 1 , wherein

the decorative medium printing program controls, when executed by the controller, the first adhesion ratio and the second adhesion ratio such that a difference of a luminous reflectance in each of the first region and the second region of the lustrous image is 1.53% or more and 5.79% or less.

3 . The image formation apparatus according to claim 1 , wherein

the decorative medium printing program controls, when executed by the controller, the non-lustrous image formation unit to form a coating image formed of the non-lustrous developer overlapping with the non-lustrous image on the second surface of the transparent medium.

4 . The image formation apparatus according to claim 3 , wherein

the decorative medium printing program controls, when executed by the controller, the non-lustrous image formation unit to form the coating image formed of the non-lustrous developer of black or white color.

5 . The image formation apparatus according to claim 4 , further comprising:

a fixation device configured to fix the non-lustrous image and the lustrous image formed on the transparent medium to the transparent medium, at a fixation temperature based on the control of the controller, wherein

the decorative medium printing program controls, when executed by the controller, the fixation temperature when fixing the coating image to be lower than that when fixing the non-lustrous image or the lustrous image.

6 . The image formation apparatus according to claim 1 , further comprising:

a fixation device configured to fix the non-lustrous image and the lustrous image formed on the transparent medium to the transparent medium, based on control of the controller, wherein

the decorative medium printing program controls, when executed by the controller, the non-lustrous image formation unit to form the non-lustrous image on the first surface of the transparent medium and the fixation device to fix the non-lustrous image to the transparent medium, the reconveyance mechanism to return the transparent medium from downstream to upstream of the transfer part with the transparent medium being flipped over, and then control the lustrous image formation unit to form the lustrous image on the second surface of the transparent medium and the fixation device to fix the lustrous image to the transparent medium.

7 . The image formation apparatus according to claim 1 , wherein

the lustrous image formation unit configured to expose an image carrier with exposure light emitted from an exposure device to form an electrostatic latent image on the image carrier, and develop the electrostatic latent image with the lustrous developer to form the lustrous image, and

the decorative medium printing program controls, when executed by the controller, the lustrous image formation unit to form the lustrous image such that a degree of the exposure light per unit area is different between the first region and the second region.

8 . The image formation apparatus according to claim 1 , wherein

the lustrous image formation unit comprises:

a first lustrous image formation unit configured to form a first lustrous image on the second surface of the transparent medium at a third adhesion ratio; and

a second lustrous image formation unit configured to form a second lustrous image on the second surface of the transparent medium at a fourth adhesion ratio different from the third adhesion ratio for the first lustrous image, wherein

the decorative medium printing program controls, when executed by the controller, the first lustrous image formation unit and the second lustrous image formation unit to form the lustrous image including the first region formed at the first adhesion ratio and the second region formed at the second adhesion ratio, by combining the first lustrous image formed at the third adhesion ratio and the second lustrous image formed at the fourth adhesion ratio.

9 . The image formation apparatus according to claim 8 , wherein

the decorative medium printing program controls, when executed by the controller, the first lustrous image formation unit to form the first region of the lustrous image at the first adhesion ratio by forming the first lustrous image at the third adhesion ratio being equal to the first adhesion ratio and the second lustrous image formation unit to form the second region of the lustrous image by forming the second lustrous image at the fourth adhesion ratio being equal to the second adhesion ratio.

10 . The image formation apparatus according to claim 8 , wherein

the decorative medium printing program controls, when executed by the controller, the first lustrous image formation unit to form the first lustrous image at the third adhesion ratio in an area corresponding to the first region and the second region of the lustrous image, and the second lustrous image formation unit to form the second lustrous image at the fourth adhesion ratio in an area corresponding to the first region of the lustrous image overlapping with the first lustrous image.

11 . The image formation apparatus according to claim 8 , wherein

the decorative medium printing program controls, when executed by the controller, the first lustrous image formation unit and the second lustrous image formation unit such that a bias voltage applied when developing the lustrous developer by the first lustrous image formation unit and a bias voltage applied when developing the lustrous developer by the second lustrous image formation unit are different from each other.

12 . The image formation apparatus according to claim 8 , wherein

the decorative medium printing program controls, when executed by the controller, the first lustrous image formation unit and the second lustrous image formation unit such that a degree of exposure light per unit area when performing exposure processing by the first lustrous image formation unit and a degree of exposure light per unit area when performing exposure processing by the second lustrous image formation unit are different from each other.

13 . An image formation method performed by an image formation apparatus when executing a decorative medium printing program, the image formation method comprising:

forming, by a non-lustrous image formation unit, a non-lustrous image of a non-lustrous developer on a first surface of a transparent medium;

before or after the forming of the non-lustrous image, forming, by a lustrous image formation unit, a lustrous image of a lustrous developer comprising a metallic pigment including a first region and a second region on a second surface that is an opposite surface of the first surface of the transparent medium; and

after forming one of the non-lustrous image and the lustrous image and before forming the other of the non-lustrous image and the lustrous image, flipping over the transparent medium by a reconveyance mechanism of the image formation apparatus, wherein

in the forming of the lustrous image, a difference between a first adhesion ratio and a second adhesion ratio is 18.75% or more and 37.50% or less, where the first adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the first region, and the second adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the second region.

14 . An image formation apparatus comprising:

a storage storing a decorative medium printing program;

a first image formation unit configured to form a first image of a non-lustrous developer;

a second image formation unit configured to form a second image of a lustrous developer comprising a metallic pigment;

a conveyance path that extends from a medium feeder to a discharge port through a transfer part at which the first image and the second image are transferred to a transparent medium which is a transparent medium;

a reconveyance mechanism including a reconveyance path and configured to return the transparent medium from downstream to upstream of the transfer part with the transparent medium being flipped over; and

a controller configured to control, based on printing data, the first image formation unit and the second image formation unit, and the reconveyance mechanism, wherein

the decorative medium printing program controls, when executed by the controller, (i) the first image formation unit to form the first image on a first surface of the transparent medium, the reconveyance mechanism to return the transparent medium from downstream to upstream of the transfer part with the transparent medium being flipped over, and the second image formation unit to form the second image including a first region and a second region on a second surface of the transparent medium, which is an opposite surface of the first surface of the transparent medium, or (ii) the second image formation unit to form the second image including the first region and the second region on the second surface, the reconveyance mechanism to return the transparent medium from downstream to upstream of the transfer part with the transparent medium being flipped over, and the first image formation unit to form the first image on the first surface of the transparent medium, thereby obtaining the transparent medium that comprises the first image on the first surface and the second image on the first region and the second region of the second surface, such that a ratio of a second adhesion ratio to a first adhesion ratio is 62.50% or more and 81.25% or less, where the first adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the first region of the second surface, and the second adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the second region of the second surface.

15 . An image formation method performed by an image formation apparatus by executing a decorative medium printing program, the image formation method comprising:

forming, by a non-lustrous image formation unit, a non-lustrous image of a non-lustrous developer on a first surface of a transparent medium;

before or after the forming of the non-lustrous image, forming, by a lustrous image formation unit, a lustrous image of a lustrous developer comprising a metallic pigment including a first region and a second region on a second surface that is an opposite surface of the first surface of the transparent medium; and

after forming one of the non-lustrous image and the lustrous image and before forming the other of the non-lustrous image and the lustrous image, flipping over the transparent medium by a reconveyance mechanism of the image formation apparatus, wherein

in the forming of the lustrous image, a rate of a second adhesion ratio to a first adhesion ratio is 62.50% or more and 81.25% or less, where the first adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the first region, and the second adhesion ratio is an amount of the lustrous developer adhered to the transparent medium per unit area in the second region.

16 . An image formation apparatus comprising:

a non-lustrous image formation unit configured to form a non-lustrous image and a correction image of a non-lustrous developer on a medium;

a lustrous image formation unit configured to form a lustrous image of a lustrous developer on the medium; and

a controller configured to control, based on printing data, the non-lustrous image formation unit and the lustrous image formation unit, wherein

the controller is configured to control the non-lustrous image formation unit to form the correction image in a second region excluding a first region on a surface of the medium, and control the lustrous image formation unit to form the lustrous image including the first region and the second region superimposed on the correction image on the surface of the medium, and control the non-lustrous image formation unit to form the non-lustrous image superimposed on the lustrous image, such that a difference of a second adhesion ratio from a first adhesion ratio is set to 18.75% or more and 37.50% or less and an adhesion ratio of the correction image is set to a value same as the difference, where the first adhesion ratio is an amount of the lustrous developer adhered to the medium per unit area in the first region, and the second adhesion ratio is an amount of the lustrous developer adhered to the medium per unit area in the second region.