| Q1:What is the difference between visible light type
material and a near infrared type material? |
 |
|
|
A1:When a near infrared light (700nm or greater laser) is used as the
exposure light source, incident light and light reflecting from the substrate
surface causes interference, which generates interference patterns in the image.
To prevent this, near infrared type material has 2 additional features compared
to visible light type material.
1) Light absorption layer (in order to absorb the incident and reflected light)
2) Roughening of the substrate surface (in order to scatter the reflected light)
|
| Q2:What is required for erase? |
|
|
|
A2:A light image of the previous pattern (called a "residual image"
or "ghost") remains on the material during its next rotation. This is
caused when part of the carrier generated by the exposed portion is trapped inside
the layer, so it cannot reach the outer surface quickly enough before the next
process. Ghosting tends to become more of a problem at longer wavelengths, which
cause light to penetrate more deeply.
When erase is used to overcome this problem, it is necessary to select a wavelength
that is close to (actually a bit shorter than) the exposure wavelength.
|
| Q3:Why is there no high-charge type available for near
infrared type material? |
|
|
|
A3:Because of its thicker layer, the chargeability of a high-charge
type material is more than twice that of a standard charge type material.
The part of the carrier generated by the erase light that is trapped inside the layer
is moved to the surface by the strong electric field following the charging process,
which neutralizes the surface charge.
The longer the wavelength, the deeper the
light penetrates, and the greater the volume of carrier that is trapped, leading
to a noticeable drop in charging. In the case of a long wavelength exposure system
that requires use of a long wavelength erase light (described in Q2, above), the
long wavelength erase light increases the drop in charging. Currently, it is difficult
to improve chargeability by making the layer thicker.
|
| Q4:What indicates the end of photoconductive material
service life? |
|
|
|
A4:Photoconductive material is at the end of its service life when
friction causes wear of the surface and deterioration of the material's characteristics.
The a-Si drum has a very hard surface protection layer, which keeps the amount
of wear at a level less than 0.5micron meter after 3 million sheets.
|
| Q5:Is the photoconductive material reusable? |
|
|
|
A5:The aluminum substrate is reusable.
The layer is nontoxic, so no special handling is required when disposing of it.
|
| Q6:Is the a-Si drum available with non-standard custom
specifications? |
|
|
|
A6:Yes.
Since the a-Si drum is custom made, customers can specify size, layer specifications
(characteristics), shipping configuration, etc.
|
| Q7:Can a-Si photoconductive material be produced in belt
form? |
|
|
|
A7:With the a-Si semiconductor, application of extreme pressure can
cause the layer network to break, resulting in a loss of semiconductor characteristics.
Since some solar cell batteries and other devices are being manufactured in sheet
form, however, we cannot rule out such a possibility for the future.
|
| Q8:Can other materials other than aluminum be used for
the substrate? |
|
|
|
A8:Though aluminum is the ideal substrate material from the viewpoint
of layer adhesion, please feel free to contact KYOCERA concerning specific inquiries
about using other materials.
|
| Q9:Are specifications available? |
|
|
|
| A9:Though there are standard specifications that cover external appearance
and electric characteristics, other items depend on customer specifications for
each customized design. |
Japan
Page Top