• ETRI Journal
• /
• v.35 no.5
• /
• pp.927-930
• /
• 2013

We propose a visible light communication system in which the color and brightness are controllable. Pulse width modulation and variable pulse position modulation (VPPM) schemes are used to control the color and brightness, respectively. A digital algorithm to decode VPPM signals is suggested and implemented. A seamless transmission is observed in a testbed experiment under various environmental conditions. The proposed scheme can be applied to emotional-lighting-based wireless optical communication.

• Journal of the Ergonomics Society of Korea
• /
• v.18 no.2
• /
• pp.91-102
• /
• 1999

There are various kinds of good feelings in indoor environment such as comfort, pleasure, delight, refreshment, geniality, etc. Each feeling is interrelated with other complex elements of senses such as warmth, coldness, calmness, clearness, brightness, etc. In this paper, we described what is good feeling in indoor environment, and developed elements of good feelings using Emotion & Sensibility engineering approach. Resultant elements of good feelings were "comfort," "refreshment," and "freshness." Secondary, we investigated the relationships of these elements with certain elements of senses. "Comfort" is related with "warmth, calmness, brightness, and very clearness in indoor air." "Refreshment" and "freshness" are related with "coldness, moderately calmness, very brightness, and very clearness in indoor air." The relationships were formulated as a fuzzy model. By applying human intuition to this model, we could determine physical ranges of "comfort, refreshment, and freshness."

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.759-762
• /
• 2005

The LGP(Light Guide Panel) for the back light unit that is used to the 2.2" TFT LCD was designed and fabricated. The method of the pattern design which is the most important in the design of the LGP was converted the V-cutting method into the Dot method. This newly developed Dot method provided a good uniformity in the brightness at the LGP, which was a very difficult problem to solove in the V-cutting method. The experiment result of the newly designed LGP shows the brightness uniformity 90% and the brightness 3656 $cd/\;m^2$ which is 20% higher than the commercial products.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1062-1065
• /
• 2004

We have analyzed the cause of black "mura" and measured it in prism light guide plate(LGP). Properties of components used in a backlight uint(BLU) have changed by simulation tool. We get major factor of black "mura" for improvement in prism LGP. For the improvement of black "mura", removal of brightness "mura" at input light part must precede preferentially because of reflection characteristic of the prism LGP. Removal of brightness "mura" is improved by hanging of input light part in LGP and dispersion treatment.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1233-1235
• /
• 2004

We have designed High Performance Prism LGP in 17 inch TFT-LCD. In test result to embody high brightness BLU in case of LGP of base and upper surface with 17 inch, thickness 8mm adding prism construct, it is superior brightness improvement than previous that of printing form about some 20% and in this course to embody actual material it succeeded prism LGP production by 17 inch injection form process.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.243-246
• /
• 2004

In this paper, we have proposed the contrast control method using brightness preserving on the FPD(Flat Panel Display). The proposed algorithms consist of three blocks: the contrast enhancement, the white-level-expander, and the black-level-expander. The proposed method has employed probability density function in order to control the brightness of the image changed extremely. In order for real-time processing, we have calculated cumulative density function using the linear approximation method. The image histogram and image quality were compared with the conventional image enhancement algorithms. The proposed methods have been used in display devices that need image enhancement such as LCD TV, PDP, and FPD.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.2
• /
• pp.98-104
• /
• 2003

This paper proposes the design of a multi-color lamp using high brightness RGB LEDs for color variation. Appropriate number of RGB LEDs is so chosen according to the color mixing theory that the overall LEDs represent a color temperature of 6500K. Also, the chosen RGB LEDs are suitably arranged by using an optical design program. The lamp has an internal controller circuit, so it can be directly connected to the existing incandescent lamp socket. It's main body is comprised of two PCB layers. The upper layer contains 44 LEDs and the lower one has a simple microcontroller-based PWM control circuit. The lamp has functions of both ON/OFF control and PWM control, and enables color variation of over 100,000 colors and of more than 10 patterns.

• Journal of Surface Science and Engineering
• /
• v.29 no.4
• /
• pp.253-260
• /
• 1996

Regular spangle hot dip galvanized steel sheets were made in the zinc bath containing a small amount of Al and with the addition of Pb, Sb, Sb-Mg, Sb-Cu and Bi respectively whose average glosses were measured. Zero-spangle hot dip galvanized steel sheets were also made by spraying a 2% $NH_4H_2PO_4$ solution on molten coating surfaces with exactly the same chemical compositions as above used for regular spangle and whose glosses and corrosion losses were also evaluated. For manufacturing zero- spangle hot dip galvanized steel sheets with high brightness, the zinc bath with 0.02%Sb and the spraying of a 2% $NH_4H_2PO_4$ solution were proposed and for better brightness and corrosion resistance, the zinc bath with 0.02% Sb-0.50%Mg and the spraying of a 2% $NH_4H_2PO_4$ solution were also proposed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.494-499
• /
• 2004

A ion source using inductively coupled plasma has been tested in order to test its feasibility as a high brightness ion source for focused ion beam. When operating the ion source with filter magentas in front of plasma electrode for a negative ion source, lower remittances are expected. Extracted beam remittances are measured with an Allison-type scanning device for various plasma parameters and extraction conditions. The normalized omittance has been measured to be around 0.2$\pi$mmmrad with beam currents of up to 0.55 ㎃. In particular, noting that multicusp magnets have a role in decreasing the remittance as well as increasing plasma discharge efficiency, transverse magnetic field has been confirmed to be a useful tool fur decreasing remittance via electron energy control.

• Journal of the Korean Society of Industry Convergence
• /
• v.1 no.2
• /
• pp.55-64
• /
• 1998

This paper deals with the effects of fluorescent lamp description and luminance level on the occupant's brightness perception and other sensation in building interiors. The following experiments were conducted: the subjects compared on room lit by daylight fluorescent lamps with the other room lit by the different lamp description at equal luminance at equal luminance level. The degree of that effect decreased with a rise in luminace level. The brightness perception had high correlation with the visual clarity and no correlation with favorite sensation.