What is the Slit Glass on a Copier?

Friday, October 18th, 2013

You may have heard the term “slit glass” before when reading your office copier manual. We admit that it’s not the most common of terms so if you are not familiar with it, we recommend you read this article.

Slit glass has optical properties that are similar to regular glass but without some of the negative qualities. The material is virtually unbreakable, has no micro cracking, and has a 1.64 refractive index. Typically the glass used for slit glass has a 1.52 index.

Glass slits can be used for any application that requires non-isolation, transparency, or non-conductance. They are used for everything from anodic bonding to phase-shifting. The medical, pharmaceutical, telecom, and optical industries all have a wide range of applications for slit glass. When slit glass is used in digital copy machines and multi-functional printers (MFPs) it consists of the piece of glass that the image passes through right before it strikes the drum.

While older analog copiers used the whole glass with mirrors to send images to the photoconductor, digital copiers use slit glass. The machine passes an image along the glass and uses mirrors to send it to the CCD unit. The CCD unit converts the analog data into digital data. The original only moves over the slit glass when someone uses the processor or document feeder. The image never gets copied directly from the glass where the person has placed his original.

Why does slit glass leave lines?

Every digital copier, fax machine, and multi-functional printer is equipped with slit glass as a means of scanning images. Eventually this glass gets dirty, resulting in lines on copies and transmitted faxes. When there are lines on a copy that is made through the processor or document feeder, it is very likely that the issue is stemming from dirty silt glass.

How do you clean the slit glass on your copier?

Take the following steps to get rid of lines on copies when you’re using the document feeder:

  1. Lift the document feeder. You should be able to see a narrow glass strip on the left side of the glass panel. It is approximately 1 inch by 12 inches. This glass is the slit glass.
  2. Grab a cotton towel and soak it with alcohol. An alcohol swab also works well. You can use glass cleaner, but for common copier slit glass debris, such as white out and ink, it is not as effective as alcohol. Alcohol swabs are inexpensive and readily available. They come in small sealed pouches.
  3. Let the spot soak for a minute to loosen the debris. If alcohol does not do the trick, contact a local copier vendor for advice and instruction.
  4. Go over the slit glass with a lint-free cotton towel saturated with glass cleaner and dry the slit glass to eliminate streaks. Avoid spraying cleaner directly onto the glass, as some of the solution will work its way into the copier.

If you have any questions about your office copy machine, please don’t hesitate to contact UCI. UCI is an Amarillo copier company that sells a variety of copiers and has an outstanding copier technician response time. Family owned and operated, UCI serves the entire Texas Panhandle. Whether your copier needs to be repaired or replaced, UCI is the place to call.