Q: Whatís the difference between a true color sensor and a color registration mark sensor?
A: True color sensors can be taught to detect minute color differences (for example, it can tell dark blue from black), while color mark sensors detect a gray scale change in color. True color sensors reflect light off a target using a white LED and red, green and blue filter elements. A color value is then assigned to the light returning to the sensor based on the amount of light reflecting off the target. Click here to see Banner's QC50 true color sensor.
With color mark sensors, the sensor uses just an LED and no filters. The sensor distinguishes between the target color based on how it contrasts with the background color.
Q: Isnít it better to use a true color sensor rather than a color mark sensor?
A: Not always. A large number of color sensing applications can be done quite effectively by detecting a gray scale change in the color mark. In these instances, we recommend you use a color mark sensor like the R58E, especially in high-speed applications. A true color sensor is required when sorting out targets that differ only in color, for example, when you need to distinguish between light blue and dark blue. However, when distinguishing a registration mark on a constant background, a color mark sensor is your best choice.
Q: Iíve used the R55F in the past. Should I consider upgrading to an R58E?
A: The R58E represents Bannerís commitment to continuous product improvement and it benefits from the newest technology. If youíve used the R55 or R55F and are satisfied with it, there is really no reason to upgrade, unless your application has changed. Remember too that R55F fiber optic units offer the convenience of a tiny sensing point and the ability to work in wet or extremely hot environments.
Q: Why would I choose an R58E over another Banner color mark sensor?
A: With the R58E, you can have the convenience of using one device for multiple applications at a very affordable price. It also is especially useful in applications that involve multiple substrate challenges and have high speed requirements.
Q: How can I maximize sensing in my high-sensitivity applications?
A: Use the dynamic TEACH function to teach the sensor a series of conditions on the fly. The R58E takes multiple samples of a registration mark against its background and is able to automatically set the sensitivity at the optimum level.
Q: Is it true that processing time for the color mark sensor affects speed?
A: Speed is more of an issue for a true color sensor rather than a color mark sensor. The R58E can perform 10,000 actuations per second, which is really pretty fast!
Q: Does having 3 LED colors affect the sensorís response time?
A: No. After the initial TEACH process, the R58Eís response time is the same as comparable registration mark sensors. The R58E has a 50 microsecond response time which allows 15 microsecond repeatability.
Q: How do I pick the right LED color for my application?
A: With the R58E, you do not need to choose an LED color. The R58E selects the proper LED color automatically during the initial TEACH function. However, when using a monochromatic color mark sensor, resources such as color selection charts are used to select the proper LED color.