Sanyo Electric Co Ltd will release the "eneloop lamp," a rechargeable light that can be used as both an interior lamp and a flashlight.
"The Kobe earthquake is the starting point," the company said. "We aimed at designing a shape that is really helpful in case of emergency."
The bud vase-shaped lamp has a maximum diameter of 121mm and a height of 221mm. It is equipped with a rechargeable battery and LEDs for lighting applications at the bottom. Sanyo combined the functions of both an interior lamp and a flashlight so that the lamp is used on a daily basis and users can easily find it in case of emergency.
The eneloop lamp uses two "eneloop" nickel-metal-hydride batteries. When in a charging stand, whose diameter is 100mm and height is 15mm, it can be fully charged in about 12 hours. Because its self discharge is small, it is unlikely that the lamp cannot be used due to battery exhaustion in a time of disaster.
Though there is no manufacturer's suggested retail price, the pricing is expected to be ¥15,000 (approx US$156). Sanyo Electric will release the lamp Sept 11, 2009, with a sales target of 5,000 units in the first year.
When the core module at the bottom of the lamp is removed, AA-size eneloop batteries can be replaced. So, the lamp can be used as a battery charger while not being used as an interior lamp. The battery, LED packages and circuit board are integrated in the core module.
Initially, Sanyo Electric considered installing the battery in the cylindrical part of the lamp. However, in that case, the battery blocks the light. And if the upper part of the lamp is damaged by dropping the lamp, it cannot be used as a light. Therefore, the company integrated the components in the core module at the bottom.
The secondary battery is charged by a non-contact charging method. The design of the eneloop lamp was enhanced by the fact that there are no metallic contact on the lamp or the charging stand. The power transmission efficiency between the stand and the lamp is about 60%, which is equivalent to that of the Wii controller.
"We found difficulty in adjusting the charging position because the bowl-shaped lamp has to be placed on the flat stand," Sanyo Electric said.
The eneloop lamp features three modes: the "white lamp" mode for use as an interior lamp, the "blue lamp" mode for use at bed side and the "flashlight" mode. When the upper part of the lamp is pressed down, a switch at the bottom is pushed, changing the mode.
White lamp mode
Two white LED units are used to produce white light, whose amount can be changed by switching between the "clear mode" and "fade mode" (the former is brighter). When fully charged, the lamp can be used for three hours in the clear mode and 45 hours in the fade mode. The two modes can also be switched by rotating the lamp and activating the embedded three-axis acceleration sensor.
Blue lamp mode
The blue lamp mode, which Sanyo Electric claims promotes secretion of serotonin (neurotransmitter) with blue light and has a healing effect, features two lighting modes. One is the "healing mode," in which the lamp continuously blinks on and off. And the other is the "flicker mode," which slowly turns on and off the lamp. When continuously used in the blue lamp mode, the lamp can be used for about 12 hours in the healing mode and about 16 hours in the flicker mode.
Two blue LED packages and two green LED packages are used for the blue lamp mode. The green LED packages were added to create soft light.
In the flashlight mode, which is the brightest mode and uses four white LED units at the bottom, the lamp can be continuously used for about six hours. When the user grabs the upper part of the lamp and tilts it at 90° or more, the acceleration sensor detects the tilt and changes the mode to the flashlight mode so that the lamp can be used as a flashlight.
Also, if the lamp falls over in an earthquake, it automatically lights up, enabling the user to easily locate it.
The shape of the eneloop lamp is designed with disasters in mind. When the lamp is shaken after falling over, it rolls in a circular motion centering on the upper part because of its bud vase-shape. According to Sanyo Electric, the lamp can be found more easily than a normal cylindrical flashlight, which tends to roll on the floor.
The lamp is made of polycarbonate and 2.5mm thick. The robustness of the lamp was decided assuming the case where it falls from a desk or table with a height of about 70cm to a wooden floor, the company said.