Proceedings of 1st International Symposium for Color Science and Art 2019

Development of a Color Mixer for Mixed-Color Education andIts Outreach Activities
S. Nakadate, Y. Tokuyama, Y. Kume, M. Shibuya, J. Chen, Y. Azuma, andT. Moriyama
Tokyo Polytechnic Univ., 1583 Iiyama, Atsugi, Kanagawa 243-0297, Japan
2.2 Wiring and placing the electric parts properly
The wires are inserting to the holes of thecorresponding colors of the breadboard, and electric partsof LEDs, variable resisters, fixed resisters are also wired
on the breadboard. The electric circuit for lighting theLEDs is a simple series circuit of the LED and resistances,where +4.5 and zero volts lines are placed in the bottomand upper holes lines respectively in the breadboard. The
resistances of the fixed and variable resisters are 33 [Ω]and 10[KΩ] respectively. High luminance and diameter
5mm red LEDs with wide directivity of 60 degrees areused in which typical DC forward current and voltage for it
are 70 [mA] and 2.2 [V] respectively, whereas they for thegreen and blue LEDs are 50 [mA] and 3.3 [V]. The same
fixed and variable resisters are used for three color LEDsto make craftwork easily.
2.3 Lighting LEDs to confirm circuit normal operation
The cables from a battery box are connected to thebreadboard to confirm the circuit correct as shown in Fig.2.
The three LEDs are tightened with a rubber band to forma triangle shape.

ABSTRACTA craft kit of "Color Mixer" was developed tounderstand easily the principle of reproducing colors
while enjoying the craftwork using three LEDs. The
composition of the kit, its outreach activity and its
educational effect will be presented.
1. INTRODUCTION"Color" in television and printing is one of importantsource of information. The basic principle of color
reproduction is the combination of basic colors (mixedcolor)[1]. In self-emissive display like a TV, color
reproduction is performed by additive color mixing,
whereas in non-self-luminous display like a printing, color
reproduction is performed by subtractive color mixing.
However, these principles of color reproductions using
color mixing are not commonly known to the youth. We
developed, therefore, a craft kit so-called "Color Mixer "tounderstand easily the principle of reproducing colors with
mixed color. In this paper, we will present the compositionand optical system of the craft kit and its outreach activity
and educational effect for education of color reproduction.
2. COMPONENTS AND MAKING PROCESS OF THE
COLOR MIXER
A craft kit of color mixer will be presented in this section
with describing its components and the making process.
2.1 Electric parts
Electric parts using in the color mixer are shown inFig.1 which are composed of three LEDs of red, green
and blue colors, three variable resisters, a battery case ofAA batteries, seven cables, three fixed resisters,
breadboard and three AA batteries. Color marks
corresponding to LEDs and cable colors are drawn on thebreadboard to make it easier to insert them to the holes inthe breadboard.

Fig.2. Lighting LEDs to confirm circuit correct
2.4 Assemble frame of LED lantern and combine itwith the LED circuit
A large screen sheet made from tracing paper ispasted to a cardboard properly to make a LED lantern thatis an outer case of the LED.
The cardboard pasted with the large tracing paper isfolded and pasted with double-sided tapes to assemble
the LED lantern box. The breadboard with the LED circuitis combined to the lantern box by adhering to its box bytape on the back of the breadboard as being careful thatthe middle of the three LEDs will be in the middle of thebox.
2.5 Pasting top screen to lantern body andcompletion of the color mixer

Fig. 1 Electric parts of this craftwork29

Proceedings of 1st International Symposium for Color Science and Art 2019
screen.
Patterns obtained on the top screen are shown in Fig.5
in which transparent and absorbing circle masks arecorresponding to additive and subtractive color mixings,
respectively. The feature of this color mixer is in easily
obtaining the patterns for the both case by merely sliding
the mask.

The square tracing paper is pasted as the top screen of
the lantern body as shown in Fig.3. Push out the mask
sheet into one slit in the lantern box and pull it out fromthe other slit to insert the mask sheet into the body. The
completion form of the color mixer is shown in Fig.3,
where additive and subtractive color mixings can beconfirmed on top screen with moving the mask sheet.
Light intensities of three color LEDs are changeable byturning the knobs of variable resistors and it makes color
variable on the top screen of the color mixer.

4. OUTREACH ACTIVITIES
Outreach activities from 2014 to 2018 years using thecolor mixer are summarized in Table 1. The most active
and longest activity was the science fair where many
young people from junior high school to high school
students participated to make the color mixer during about
20 minutes. Many participants enjoyed in making the color
mixer very much and learned how to reproduce colors ona TV and a printing, it became clear from theirquestionnaire results.
Table 1. Summary of outreach activities
Eventnameand its venue
Science fair for
Kanagawa
Teenagers,
Yokohama
Kanagawa
Japan
Wakuwaku(Exciting) kougei
land,
Atsugi
Kanagawa
JapanExperience
workshop tocreate color,
Atsugi
KanagawaJapan

Fig.3. Completion form of color mixer
3.

OPTICAL SYSTEM AND BASIC OPERATING
PRINCIPLE OF COLOR MIXER
The basic operation principle with its optical system will
be presented in this section.
ScreenMask

3 color light source

Fig.4. Basic arrangement of the color mixer
The color mixer is basically composed of a light sourceof three LEDs, a mask, and a top screen made from atranslucent tracing paper as shown in Fig.4. For the caseof additive color mixing the arrangement of the mixer isdrawn in left half of the figure, whereas it is drawn in theright half of the figure in the case of subtractive color
mixing. Light from each LED is transmitted or absorbed by
the single mask and projected on to the translucent

Targetparticipants
Middle andhigh school
students andtheir parents

The number ofparticipants
190 (July 2014)
200（July 2015）
200（July 2016）
160（July 2017）
168（July 2018）

Elementaryand junior highschoolstudents andtheir parents

50 (July 2014)
21 (July 2018)(Excludingparents)

Elementaryand junior highschoolstudents andtheir parents

50 (October2017)(Excludingparents)

5. CONCLUSIONS
A color mixer for education of color mixing has beendeveloped and its components, the making process, thebasic principle of operation, and so on have been
described. Outreach activities using the color mixer werealso mentioned. It is important for children to learn andthink about how to reproduce colors while making thecraft kit of color mixer. It is also useful for their lives, so weneed to continue the outreach activity in the future.
Its details with the educational effect anddemonstration will be presented on site. This work wassupported by “FY2016 MEXT Private University Research
Branding Project”.
6. REFERENCES[1] Hunt R. W. G., [The reproduction of Colour Sixth
Edition], John Wiley & Sons Ltd, Chichester,
9-30(2004).

Fig.5. Patterns on the top screen of the color mixer

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