Paint Colorimeter Project
Nick Pederson
College of Engineering Student
Oregon State University
Corvallis, Oregon, USA
George Hernandez
College of Engineering Student
Oregon State University
Corvallis, Oregon, USA
Johnny Chen
College of Engineering Student
Oregon State University
Corvallis, Oregon, USA
Abstract—The Paint Colorimeter is an easy to use device that will help consumers match the colors of existing surfaces. This device will helps reduce the costly expenses of inaccurately matched paint. The paint colorimeter project will create a device that is capable of taking various samples and accurately translate the colors. The components to the device are a battery, a color sensor, and an embedded computer system. This project will have risks, an overall goal, and a timeline to follow.
Keywords—battery unit, color sensor, embedded computer system
I. Context
Paint is used by many consumers for various work. There are many selections of paint colors to choose from, but when a consumer wants to select a specific color to match existing surfaces, they are left with little option. The consumer will either take a picture of the surface and compare the picture to color samples from vendors or, they will take a booklet of color samples from the vendors to put up against the surfaces they want to match. Sometimes the color match will turn out right while other times it does not. When this happens the expenses from the consumer standpoint is costly. At the same time it is costly for vendors to waste resource and be left with unhappy consumers. Both vendors and consumers will be more happy with the convenience of a newly proposed portable paint colorimeter project from Hewlett Packard (HP).
II. Purpose and Structure
A. Purpose
This document will provide information in regards to the portable paint colorimeter project. The purpose of the paint colorimeter project is to inform consumers that there is a convenient and easy option available for matching paint.
B. Structure
The following sections will provide an introduction to the project, information on the research and technology concerning the device, followed by the risks and goals of the project. Finally, the stakeholder’s information will be provided and the timeline of the project.
III. Introduction
Consumers have struggled with paint matching for decades. Obtaining paint samples has proven tedious and error prone on the consumer's side. When the sample is obtained, its then taken to a vendor and matched using the vendor's color matching device. After the matched paint is ready, the consumer waits for the paint to dry to verify that the paint matches. From experience, wet paint appears different than dry paint. This process can be made easier on the consumer if the sample collected were nondestructive and accurate. Current methods to obtain a color sample include cutting out a sample the size of a quarter and giving that to a paint store. Another method involves holding paint sheets to the desired surface and manually choosing the best match. The first option involves damaging the surface of interest to obtain the paint sample. The second method is prone to error due to the numerous options on a single sample sheet. The Paint Colorimeter project aims to solve the paint matching problem with a portable device that is consumer friendly.
IV. Theory
Any color can be defined by a combination of three unique colors which are usually red, green, and blue [1]. These colors are commonly used by paint companies to define specific colors and shades. Since white light is made up of these three colors, we can flash a white light onto a surface to conduct our testing. When white light hits a colored surface all of the colors are absorbed within the surface except for the ratios of red, green, and blue light that make up the color of that surface. The light that is not absorbed is reflected off the object for our eyes to see [1]. So by illuminating an object with white light we can see the color of the object by sensing the intensity of the red, green, and blue light that reflects off of it. With the Paint Colorimeter not being a visual colorimeter, the color spectrum used as a reference will come from the realistic spectrum. The realistic spectrum places blue, green, and red at 400nm, 520nm, and 700nm wavelengths respectively [2].
V. Technology and Research
A. Power Unit
The portable paint colorimeter project will require a battery unit to make the device portable. The battery unit will provide power to the portable paint colorimeter. The battery used be a rechargeable battery that is rated to last approximately at least five hours of operation time. Recent studies show that lithium polymer battery are popular among a variety of applications [3]. This is because lithium polymer battery is rated for high performance with significant amount of energy density, is rechargeable, and is able to operate phenomenally under room temperature [3]. Furthermore, lithium polymer battery has a slow linear degradation rate [3]. Lithium polymer battery is an ideal candidate for this paint colorimeter project due to its high performance and rechargeability.
B. Sensors
Physical samples taken into a paint store are matched using their machines. In general, these machines use a spectrophotometer. A spectrophotometer in principle detects the wavelengths produced by objects and helps with color detection [4]. This technology is expensive, which makes it impractical to use in our device. With the use of LEDs and sensors, detecting color is still possible. Hobbyists are able to replicate the same operations by using RGB LEDs to illuminate a surface. If a red LED is flashed on a red wall, that light will be reflected back and red will be detected. If a red LED is flashed on a blue wall, the light will be absorbed by the wall and less will be reflected. This theory of operation allows us to use RGB LEDs to begin the color matching process. Through the use of microcontrollers we will be able to manipulate the incoming data from the sensors.
C. Embedded Systems
A microcontroller will be used to interpret the data from the sensors, write samples to memory, read samples from memory, and communicate with a computer. Using a microcontroller will allow us to calibrate the colorimeter by easily performing and changing mathematical operations on the data retrieved from the sensors. We then take this data and write it to onboard memory. Data is then retrieved from memory and uploaded onto a computer to allow a paint store to easily read and mix the paint. The final thing that we are utilizing the microcontroller for, is to control the user display and read button presses.
VI. Goals
The project goals for the Paint Colorimeter are as follows:
● Design a device that will take a paint sample using nondestructive methods.
● Be able to display the sample information to the user.
● Information obtained from sample able to be used at any paint store.
● Have the device last at least 4 hours on a single charge.
● Device will be portable with device dimensions dependent on hardware.
VII. Risks
In every project there are some potential risks that could be present. Below are some potential risks for the portable paint colorimeter project.
● Cost of the final portable paint colorimeter design being too expensive for consumer use.
● The portable paint colorimeter may not distinguish between close shades of certain colors accurately.
● The portable paint colorimeter may not retrieve color samples accurately on textured or shiny surfaces.
VIII. Timeline
The project timeline is subject to change as more information from our stakeholder arrives. Currently, the proposed project timeline is as follows:
● October-
○ Designing and planning specifications of the overall portable paint colorimeter.
○ Defining the project requirements.
○ Drafting the project block diagrams and descriptions.
● November-December
○ Selecting components to be used in the portable paint colorimeter such as sensors, processors, communication device, battery, physical enclosures, and codes.
○ Complete some of the project blocks for demonstration purposes
● January-
○ Begin a prototype of the portable paint colorimeter.
● February-
○ Demonstrating the project system capabilities.
○ Testing the portable paint colorimeter.
● March-
○ Finalizing the design of the portable paint colorimeter.
○ Further testing to verify functionality of portable paint colorimeter.
○ Provide a project system testing report.
● May-
○ Delivering the finalized product of the portable paint colorimeter.
IX. Conclusion
The purpose of this colorimeter is to supply consumers with a fast, non-destructible, portable, and consumer friendly way of finding a color of paint that matches the color of a desired object. Since this colorimeter uses light and a microprocessor to interpret the color of an object, it can be very fast and will only take a couple of seconds to get a measurement. Unlike most colorimeter where you need to take a small sample into a store for them to check the color, this one can be used on any surface without destroying it. The size and the battery makes this colorimeter highly portable without the need to plug it into an outlet. Finally, the LCD display along with the simplicity of use makes this colorimeter extremely user friendly.
Many colorimeters on market use photocells to get the color intensity then convert the analog signal to digital [5]. We are going to use this method along with a microprocessor to read, translate, and display the color of objects. This allows us to focus more on accuracy of the device instead of spending time trying to find a new way to read color.
Acknowledgement
Stakeholder: Mark Reed Email:
Professors: Donald Heer Email:
Rachael Cate Email:
Manager: McKay Lindsay Email:
Team Members: Nick Pederson Email:
George Hernandez Email:
Johnny Chen Email:
References
[1] Physicsclassroom.com, ‘Light Waves and Color - Lesson 2 - Color and Vision’. [Online]. Available:
http://www.physicsclassroom.com/class/light/Lesson-2/Color-Addition. [Accessed: 6- Oct- 2013]
[2] R.S. Berns, F. W. Billmeyer, and M. Saltzman, Principles of Color Technology, 3rd ed. New York: Wiley, 2000
[3] Matteo Galeotti, Lucio Cina, Corrado Giammanco, Stefano Cordiner, Aldo Di Carlo, “Performance analysis and SOH(state of health) evaluation of lithium polymer batteries through electrochemical impedance spectroscopy” Energy, Volume 89, September 2015, Pages 678-686, ISSN 0360-5442. Science Direct.
[4] A. Preiser, “Color-matching devices,” in Gadgets, House Beautiful, 2009. [Online]. Available:
http://www.housebeautiful.com/shopping/home-gadgets/a255/technophobia-color-matching/Accessed: Oct. 7, 2016
[5] Vieira, M., Fernandes, M., Louro, P., Fantoni, A., Vygranenko, Y., Lavareda, G. and Carvalho, C.N. (2005) ‘Image and color sensitive detector based on double p-i-n/p-i-n a-SiC:H photodiode’,MRS Proceedings, 862. doi: 10.1557/PROC-862-A13.4