Light sources and lighting circuits

Abstract

According to machinery statistics of the Ministry of Economy, Trade and Industry, in 2011, the quantity of incandescent electric lamps produced in Japan was 725 million units (91.0% year-on-year). Of these, 47 million units were general lamps (66.7% year-on-year) and 28 million units were halogen lamps (79.5% year-on-year). The decrease in total production quantity of incandescent electric lamps is less than 10% only because of the large quantity of automotive lamps included in the statistics. The quantity of fluorescent lamps produced was 284 million units (52.1% year-on-year), and the quantity of general fluorescent lamps, excluding backlights, was 211 million units (84.1% year-on-year). Additionally, the quantity of HID lamps produced was 8.9 million units (91.2% year-on-year). On the other hand, year-on-year sales volumes were 71.2% for general lighting electric lamps, 69.0% for halogen lamps, 85.4% for general fluorescent lamps, 25.1% for backlights, and 91.6% for HID lamps. The compact self-ballasted fluorescent lamp, which had not been separately listed until 2010, had been included in the "other fluorescent lamps" category and specific figures, although not available, are undoubtedly decreasing. According to a report by a private research company, since the Great East Japan Earthquake, sales of bulb-type LED lamps as a percentage of total sales have been increasing rapidly, but compact self-ballasted fluorescent lamps, although higher-efficiency than incandescent electric lamps, have continued to decrease slowly as a percentage of number of sales per month, and consumer awareness of energy savings seems to be directed toward LEDs. To summarize these figures, from a long-term perspective, the replacement of lamps with LED light sources has been steadily progressing, with the fastest rate of progress being exhibited for backlights and relatively slow progress for automotive lamps, which are inexpensive and used in large quantities, and for high-intensity HID lamps. Major exhibitions in 2011 were Lighting Fair 2011, which was held in March in Japan, and Lightfair International 2011, which was held in May in Philadelphia, PA in the USA. Announcements of new products or new research activities concerning incandescent electric lamps were almost non-existent. In the future, as LEDs are used more and more, incandescent electric lamps may only remain significant as a comparative example when discussing color rendering properties and the like. In recent years, although the development of fluorescent lamps has been advanced for energy savings and longer service life, outstanding new products are no longer being seen. R&D activities are also gradually decreasing despite the many remaining challenges, such as hot cathode behavior and the discharge state of an electrodeless lamp. New product development and research of LED light sources has been very active. As for bulb-type LED lamps, many new products have introduced, and in particular, lamps for which the distribution of luminous intensity toward the base direction has been made wider, which had been a challenge until last year, have been developed one-after-another, and lamps that realize a luminous intensity distribution angle of approximately 300°, which is equivalent to that of an incandescent electric lamp, have also appeared. In Japan, a cabinet order amending a portion of the Order For Enforcement of the Electrical Appliance and Material Safety Law has been promulgated, mandating that the PSE mark be affixed to bulb-type LED lamps (effective as of 7/1/2012). For HID lamps, research into understanding the mechanism of operation, mainly for ceramic metal halide lamps, is continuing as usual but almost no reports of new product development have been seen. Among other types of discharge lamps, in addition to inductively coupled electrodeless low-pressure lamps and excimer discharge lamps, there were many reports of microwave-excited discharge lamps. In addition, research into the use of carbon nanotubes as electron emission material was frequently reported. For the lighting circuit, many research reports were seen that relate to increasing the efficiency or extending the service life through adoption of electrolytic-capacitor-less technology in accordance with LED product features. There were many reports relating to PFC functions and higher output for HID lamps.