Can Infrared Radiation Detect Extra Glossy or Thick Pages in Scanning Machines?

[dmehling]

I am trying to develop a mechanism for automatically scanning documents which involves picking up pages or sheets of paper. I need a method for determining whether an extra page has been picked up. I have considered using a beam of light that would pass through the page or pages and a sensor on the other side of of the page could determine how much light has passed through. Less light passing through would indicate that the machine has picked up an extra page. What I am wondering is how would this work for very thick or glossy paper like the kind in a magazine? Would visible light be absorbed completely by the paper, and if so what other forms of energy could pass through such paper? Would infrared radiation be a possibility?

 

[mgb_phys]

Infrared might be better because it will have less effect on any optical brightening agents present on the paper. And will be less sensitive to any dye printing.

You will probably have to make some sort of self adjusting system where it constantly measures a running average of the transmission of the paper being used and responds to peaks in this rather than try and determine a fixed transmission value for all paper - which will vary with type. This will also handle both changes in the light source / detector.

Of course you will have a problem if you have a sheet of high gloss paper in the middle of a stack of newsprint.

 

[sir-pinski]

Using a beam of light and a sensor to determine the thickness of paper is a common method used in document scanning machines. However, when it comes to glossy or thick paper, visible light may not be the best option as it can be easily absorbed or reflected by the glossy surface. In this case, using infrared radiation could be a possible solution.

Infrared radiation has a longer wavelength compared to visible light, making it less likely to be absorbed or reflected by glossy or thick paper. This means that the sensor on the other side of the paper would be able to detect the infrared radiation passing through, even if the paper is glossy or thick. However, it is important to note that the amount of infrared radiation passing through the paper may still vary depending on the thickness and glossiness of the paper.

Another option to consider could be using ultrasonic waves. These waves can pass through solid objects and are commonly used in industrial and medical applications for detecting thickness and density of materials. However, implementing this technology in a document scanning machine may be more complex and costly compared to using infrared radiation.

In conclusion, while using a beam of light and a sensor is a viable option for detecting an extra page in most cases, it may not be the most effective solution for glossy or thick paper. Considering alternatives such as infrared radiation or ultrasonic waves could provide more accurate results in these situations. It would be best to conduct further research and testing to determine the most suitable method for your specific application.