巻号一覧
42 巻, 4 号
「レーザー技術が支える自動車産業の最新動向」特集号
選択された号の論文の11件中1～11を表示しています
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「レーザー技術が支える自動車産業の最新動向」特集号
特集
レーザー解説
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橋田 昌樹2014 年 42 巻 4 号 p. 294-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスPDF形式でダウンロード (186K) -
坪井 昭彦2014 年 42 巻 4 号 p. 295-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスIn the automobile industry, diligent efforts are promoting automobile development that is in harmony with the environment by offering environmental load-reducing, including better performance and functionality of car bodies and parts and greater fuel efficiency through lightweight solutions. Laser processing technology has contributed to such environmentally friendly efforts. Such new generation vehicles as electric vehicles (EV) and plug-in hybrid vehicles (PHV) are being developed and their popularity is growing; the extension of the range of applications of laser processing technology is expected. We review the application situation and the future outlook of laser processing technology in the automobile industry.抄録全体を表示PDF形式でダウンロード (1688K) -
平等 拓範2014 年 42 巻 4 号 p. 299-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスThe mechanism of air breakdown for engine ignition was investigated with the high-brightness giantpulse lasers. After the conformation of double pulses and ultrafast short pulse effects for laser-induced breakdown, we have designed a giant-pulse microchip laser for engine ignition. The output energy of 3 mJ per pulse and totally 12 mJ (sum of 4 pulses) were obtained at the pump duration of 500 μs with the optical-to-optical conversion efficiency of 19%. The pulse width and M2 value were 500‒700 ps and 1.2 ‒1.4, respectively. The brightness of the microchip laser was calculated to be > 0.3 PW/sr-cm2 and the optical power intensity of 5 TW/cm2 was estimated at the focal point of ignition. The enhanced combustion by the microchip laser ignition was successfully demonstrated in a thermo stated constantvolume chamber with room temperature with atmospheric pressure, and ignition tests for a real automobile engine were performed. A single laser pulse with energy of 2.3 mJ could ignite and drive the engine stably. It should be lowest energy ever reported for laser ignition of a real automobile engine. Finally, the world first microchip laser ignited self-consisted gasoline engine vehicle has been demonstrated by “Giant Micro-photonics”. Advantages of lean-mixture combustion should also show benefits in realization of an efficient and clean electric power cogeneration system.抄録全体を表示PDF形式でダウンロード (2291K) -
井上 大介, 市川 正, 松原 弘幸, 各務 学2014 年 42 巻 4 号 p. 306-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスIt is difficult to design small, highly sensitive LIDARs because downsizing their receiving lens degrades their sensitivity. The main feature of our system is the utilization of optical amplifiers for both the transmitter and the receiver, which enable us to exceed the detection limit set by thermal noise. In conventional LIDAR systems, the detection limit is determined by thermal noise because the avalanche photodiodes (APD) and trans-impedance amplifiers (TIA) directly detect the received signals. In our LIDAR system, the received signal is amplified by an optical fiber amplifier before reaching the photodiode and the TIA. Therefore, the signal level is boosted before the incoming signal is depleted by the thermal noise. There are conditions under which the noise figure for the combination of an optical fiber amplifier and a photodiode is superior to the noise figure for an APD.抄録全体を表示PDF形式でダウンロード (1402K) -
江塚 敏晴2014 年 42 巻 4 号 p. 310-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスHead-up displays (HUDs) mounted on vehicles have been expected to significantly improve driving safety, since eye movements and accommodation during driving can be reduced with them. In this paper, laser projector, a micro-lens array used as a transparent screen, and a concave combiner, which consist of a brand-n (a) ew laser HUD, are reviewed respectively. A method for image distortion correction is also presented. A wide field of view (17.1 by 5.7 degrees), high brightness (12,000 cd/m2), and compact size (W260 × H123 × D257 mm) have been achieved with this HUD system.抄録全体を表示PDF形式でダウンロード (2482K) -
久志本 琢也2014 年 42 巻 4 号 p. 315-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスLEDs and laser diodes have a tremendous amount of potential to innovate current and future technologies for automotive headlights. Possible benefits include environmental aspects, functionalities that will contribute to driving safety, and an attractive appearance of the headlight itself, which offers a certain level of importance in automotive styling. To gain these benefits from new light sources, optical system design plays a critical role in the utilization and in the development of headlights. Optimal light distribution and unique appearance with compact and efficient optics are the expected characteristics of typical headlights. In this paper, we describe some practical approaches of an optical system for both LEDs and lasers by examining the latest examples of our LED and laser-based products.抄録全体を表示PDF形式でダウンロード (2776K) -
各務 学, 小林 茂, 芹澤 直嗣, 平岩 徹也, 麻生 修, 後藤 英樹2014 年 42 巻 4 号 p. 320-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスThe data-rate of in-vehicle communication requires improvement due to the implementation of infotainment applications and advanced driver assistance systems. In order to meet severe in-vehicle requirements, engineers have been continuously developing a physical layer, trying to choose between a metal cable and an optical fiber. In this paper, we review the present state and some future activities regarding in-vehicle optical fiber networks especially from the aspect of both device development and standardization.抄録全体を表示PDF形式でダウンロード (2000K) -
上間 裕二, 稲見 昌彦2014 年 42 巻 4 号 p. 326-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスThis paper presents a new type of optical camouflage system based on retro-reflective projection technology, which creates augmented reality that combines virtual and real worlds. Our new setup provides multiple viewpoints by applying a novel projection array system. In our method, we achieve such a projection array system using one projection source and the system configuration. In addition, we describe an application of our system in a car. The installed system makes the backseat virtually transparent, allowing drivers to see rear blind spots when backing up.抄録全体を表示PDF形式でダウンロード (1215K) -
大越 昌幸, 井上 成美2014 年 42 巻 4 号 p. 331-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスA transparent, hard silica glass (SiO2) layer was formed on a conventional protective coat made of silicone ([SiO(CH3)2]n) on a polycarbonate plate by the 157 nm F2 laser-induced photochemical modification of silicone into SiO2. An optimum laser irradiation time of the F2 laser was found to form a crack-free SiO2 layer. The high optical transparency of the samples in the visible light region remained unchanged after the F2 laser irradiation. In the Taber abrasion test, the SiO2 layer markedly reduced the number of scratches, resulting in a low haze value. The haze values of the samples also depend on the thickness of the silicone protective coat underneath the SiO2 protective layer. As a result, the difference of haze value [δ Hz] was successfully reduced to 1.2%, compared with these of the nonirradiated sample and a bare polycarbonate plate of approximately 3.5 and 46%, respectively, which is comparable to the case of a bare silica glass of approximately 0.9%.抄録全体を表示PDF形式でダウンロード (739K)
レーザーオリジナル
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佐藤 雄二, 塚本 雅裕, 成山 達也, 中井 一樹, 松岡 史浩, 高橋 謙次郎, 升野 振一郎, 大久保 友雅 , 中野 人志2014 年 42 巻 4 号 p. 335-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスA carbon fiber reinforced plastic [CFRP] is widely used for automobile, aircraft and so on, because of high strength, lightweight and weather resistance. It is difficult to cut a CFRP plate since it is composed of complex matrix of carbon fiber and epoxy resin. The CFRP plates were cut with nanosecond lasers at the wavelengths of 1064 and 266 nm. The ablation plumes ejected from the CFRP plates were observed with an ultra-high speed video camera during the laser irradiation. After the laser irradiation, heat affected zones (HAZs) of CFRP plates were evaluated with scanning electron microscope and Fouriertransform infrared spectroscopy. The results indicated that the ablation dynamics depended on the laser wavelength and the cutting speed for 1064 nm was higher than that for 266 nm although the HAZs for 1064 nm was larger than that for 266 nm.抄録全体を表示PDF形式でダウンロード (1609K) -
藤田 雅之, 染川 智弘, 尾崎 巧, 吉田 実, 宮永 憲明, 中瀬 拓也, 小林 隆2014 年 42 巻 4 号 p. 341-
発行日: 2014年
公開日: 2020/09/07
ジャーナル オープンアクセスWe have investigated femtosecond-laser-induced surface texturing of Al-Si alloy for reducing friction. Although it had been reported for typical metal substrates such as stainless steel that the Laser-Induced Periodic Surface Structure (LIPSS) had effects for lowering the coefficient of friction, we focused our experiments on the Al-Si alloy used in industrial equipments. It was demonstrated that the surface roughness could be controlled by adjusting irradiated laser fluences due to the differences of ablation properties between Al and Si. It was confirmed that the coefficient of friction was reduced about 20% for the textured surfaces.抄録全体を表示PDF形式でダウンロード (2083K)
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