Transmissive Type Glass Charts
Transmission Type Glass Charts
These are charts for which a chrome thin film is used to form a high-precision, high-resolution pattern on a transparent glass substrate. They are utilized in evaluating optical devices. Typical pattern formations include those in which charts with various line widths and spacings are arrayed in a regular manner in order to check resolution, and those in which dot patterns and cross marks are lined up in an array shape in order to check positional accuracy. Patterns can be produced down to the micron level. The color of the chrome thin films is silver for single-layered chrome, and golden brown or dark blue for chromium oxide. Patterns are formed using high-precision laser imaging equipment.
Glass Types and Characteristics
For glass substrates, synthetic quartz and soda lime are primarily used. BK7, white plate glass, and the like are often used as well. For the front and rear surfaces of the chart, we offer anti-reflective films and a variety of coating processes to fit the usage objectives. Standard thicknesses of the glass chart substrate are 1.0 mm, 1.5 mm, 2.3 mm, 3.0 mm, and 5.0 mm, but we can accommodate custom thicknesses as well. The thinnest chart glass substrate has a thickness of 0.1 mm. Arbitrary shapes such as rectangular or circular as well as arbitrary sizes can be created, and special outline shapes, through-hole boring, counter boring, and so on are possible to a high degree of precision.
Transmissive Type Film Charts
Transmission Type Film Charts
For transmissive type film charts, black patterns are imaged onto PET material.
Patterns can be formed down to a minimum size of 20 microns.
EQUA’s film charts feature support for large sizes and precise outline machining capability.
The maximum size is 1,562 x 2,400 mm.
If a precise outline size is desired, we provide two methods to achieve this: the outline can be machined using a precision metal mold, or it can be machined using a cutting machine.
