Observation of Real Contact Area Using Laser Microscope with Wide Field of View

Nitta, Isami; Ebuchi, Rintaro; Yasuda, Yukiko; Terao, Hirotoshi

doi:10.1299/kikaic.77.631

Cited by 2 publications

(3 citation statements)

References 8 publications

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“…For this reason, observation of the engineering surface over a fairly wide region, for example 10 mm width, has rarely been conducted. In a previous study, a wide-field laser microscope was developed (Nitta et al, 2010), and a relatively wide region of contact surface able to be observed in a short time (Nitta et al, 2011).…”

Section: Micro Heater Wiringmentioning

confidence: 99%

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Visualization of contact patterns of thermal printhead for indirect thermal transfer printing

Irii

Kou

Tsukiyama

et al. 2018

JAMDSM

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Printers often face problems with large power consumption, resulting in the development of various power saving techniques. Such techniques for indirect thermal transfer printers covered in this study are also progressing. For this type of printer, most of the required electric power is consumed during the ink transfer process, in which ink on a transfer belt is heated using a heating roller with large heat capacity. To reduce the heat capacity of the heating system, the use of a thermal printhead with a low thermal capacity has been proposed. Even at low power, such a thermal printhead will immediately reach high temperatures within a specified area, shortening the warm-up time and leading to lower printer power consumption. However, thermal printheads have two problems with contact heat transfer. The first is that the thermal printhead is less likely to deform than the soft heating roller. Secondly, since the wiring for power supply is complicated, irregularities of several µm are formed on the surface of the printhead, resulting in the limited heat transfer. To evaluate these effects, distribution of contact pressure with respect to surface waviness was analyzed using the finite element method. In this study, we observed the real contact area using a wide-field laser microscope and evaluated the validity of the FEM analysis. We succeeded in visualizing the contact pattern by pressing the ultra-high transparent silicone rubber and the transparent plastic film against the thermal printhead. As a result, it was confirmed that the FEM simulation results agree with the experimental ones.Keywords : Thermal printhead, Laser microscope, Real contact area, Waviness, Visualization IntroductionIn laser printers, a fixing heater is used to fuse the pigment in place on the printing paper. After receiving print data, it takes several tens of seconds for the fixing heater to reach a predetermined temperature, after which printing commences. Since the heat capacity of the fixing heater is generally large, most of the electric power required for the laser printer is consumed by the fixing heater in the fuser unit. To solve these problems, various power saving techniques for heaters have been developed (Onodera et al., 2016, Maeda et al., 2014.Power saving techniques have also progressed in indirect thermal transfer printers covered in this study. The principles of the indirect thermal transfer printer are shown in Fig. 1 (Ukai et al., 2008), characterized by use of an indirect transfer belt. An image for printing will be first constructed on the transfer belt with an ink ribbon and the thermal printhead. Then, the image on the transfer belt is moved to another place for the fixing and transferred to the printing material by heating and pressing. In this printing method, it is even possible to perfectly print an image on uneven surfaces which are difficult to directly print on by ordinary printers. This is due to the transfer belt deforming flexibly and following the uneven surface. The power consumption of this printi...

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Section: Micro Heater Wiringmentioning

confidence: 99%

“…As mentioned in section 2.1, glass is often used as a transparent material for observe contact surfaces (Nitta et al, 2011, Nitta et al, 2013. Recently, a study of contact surface observation using ultra-high transparent silicone rubber, UHTSR, was reported (Tsukiyama et al, 2015, Masuda et al, 2017.…”

Section: Ultra-high Transparent Silicone Rubber (Uhtsr)mentioning

confidence: 99%

Visualization of contact patterns of thermal printhead for indirect thermal transfer printing

Irii

Kou

Tsukiyama

et al. 2018

JAMDSM

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“…離れているとの考え (似内，澤，2010) が導入された．しかし，実際のフランジは旋削仕上げに起因する凹凸があり，密封面の漏れ流路はそのように単純に仮定することはできない．このような考え方は，計算機や観察装置が十分でなかった当時において，接触圧力と漏れ量の関係を定性的に説明する役割を果たした．金属ガスケットシールの実用的な研究においても，密封面の表面突起同士の接触問題は確率統計的手法で取り扱われているので，漏れ量の予測は定量的ではなく定性的なものとなっている (Polycarpou and Etsion, 2000), (Nitta, 1995), , , (新田他，2005), ) では，フランジとガスケット面間の真実接触状態を厚さ 1 m の薄い高分子フィルムを用いて観察した．しかし，この方法は密封面に薄い高分子フィルムを挿入するため，膜厚が薄くても真実接触の状況に影響する可能性があった．そこで，別の方法として，従来の光学顕微鏡と比較して数百倍広い視野を持つレーザ顕微鏡 , (Nitta, et al, 2011) を利用することにした．このレーザ顕微鏡を用いれば，真実接触状態を従来法に比べて短い時間で観察できる Cross-section of an experimental apparatus, load is applied to the upper flange with four hydraulic cylinders and leaked nitrogen gas is transferred to a gas chromatograph with helium carrier gas to detect a leakage rate. Fig.…”

Section: 的手法で取り扱われている．すなわち，密封面は幾何学的な平面であり，接触圧力に応じてある平均すきまだけunclassified

Evaluation of sealing characteristics of copper gasket using laser microscope with wide field of view

Nitta¹,

Matsuzaki²,

Tsukiyama³

et al. 2014

Transactions of the JSME (In Japanese)

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To quantitatively predict leakage rates through gasket/flange interface, it is important to observe contact conditions at seal surfaces because the leakage path consists of the non-contact portions between the flange and gasket surfaces. The contact surfaces of the flanges were finished by lathe turning. In this study, we observed real contact area on gasket surfaces using a laser microscope with a wide field of view. The observations indicated that the leakage paths on the gasket surfaces were in the radial direction perpendicular to a lathe-turned groove and the circumferential direction along the groove. As the closing loads increased, the leakage paths in the radial direction disappeared and only the leakage path in the circumferential direction remained. The critical contact pressure where the leakage paths in the radial direction disappear was determined from the observation of the contact surface of the gasket. Over the critical contact pressure, the leakage rates obtained from the experiments showed good agreement with the calculated values under the assumption of laminar flow along the turned groove. Under the critical contact pressure, the recalculated values considered the leakage paths in both the radial and circumferential directions approached the experimental values.

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Observation of Real Contact Area Using Laser Microscope with Wide Field of View

Cited by 2 publications

References 8 publications

Visualization of contact patterns of thermal printhead for indirect thermal transfer printing

Visualization of contact patterns of thermal printhead for indirect thermal transfer printing

Evaluation of sealing characteristics of copper gasket using laser microscope with wide field of view

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