著者

木島 竜吾

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.23, no.3, pp.179-188, 2018 (Released:2018-09-30)

参考文献数

48

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How detailed feature of virtual world could be seen by the actual user is an important performance of VR display system, such as Head Mounted Display (HMD). The average or standard user's eyesight in a virtual world could be regarded as a performance index of the VR display system in terms of resolution. This paper aims to show the way to obtain the theoretical value of eyesight from the specifications of components that form an VR display system. This is obtained by synthesizing the total performance of an VR display system's from those of components and by comparing that with standard user's contrast sensitivity function. Through the example estimations, the valid region of the equivalent eyesight from pixel pitch, a new simple conversion from blur size to eyesight were provided.

著者

木島 竜吾 渡邊 純哉 近藤 大祐

出版者

一般社団法人電子情報通信学会

雑誌

電子情報通信学会技術研究報告 (ISSN:09135685)

巻号頁・発行日

vol.108, no.77, pp.7-12, 2008-06-02

被引用文献数

2

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A novel notion "retro-transmissive" material as an optical element for head mounted display is introduced and discussed. Using this, so called "false image projector" is proposed. This projector does not need any screen such as the retro-reflective screen that was generally used for head mounted projection system. The fundamental operating principle of the optics is discussed both in macro-view and micro-view. The simple early prototype is developped and the result of experiments indicated the optical system works as proposed operating principle.

著者

宮島 健人 木島 竜吾

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.21, no.1, pp.131-140, 2016-03-31 (Released:2017-02-01)

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The latency is a fundamental and important value in the specification of HMD. However, the HMDs of the state of the art equipped with the latency compensation, the notion of the simple lag is not enough to describe the dynamical characteristic of them. The purpose of this study is to evaluate the average latency as the equivalent simple lag and the accuracy of compensation by the experiment. Further, the dynamical distortion caused by the lag compensation is also evaluated.Oculus Rift DK2 is chosen as the target HMD of this evaluation. The average latency was approximately 26 ms without lag compensation, and it was about 1 ms with both of the Prediction and the Timewarp.

著者

箕浦 弘人 木島 竜吾 小鹿 丈夫

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.4, no.2, pp.439-444, 1999

参考文献数

13

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In the field of Mixed Reality, one area of Virtual Reality, the method of merging virtual and real spaces have been often discussed. A chromakey-imposer is often used to synthesize CG and real images, but the relation between CG and real images is either in front or behind because a general chromakey-imposer has only one chromakey plane. To make one advance in the former method of merging we propose a method to make a visual effect as if a real space is embedded in a virtual space by dividing an object space into three layers and using two chromakey planes. We tested the visual effect by treating the object space as a studio space which has a large area and a desk space which has a small area.

著者

木島 竜吾 山田 英治郎 小鹿 丈夫

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.6, no.2, pp.107-114, 2001

参考文献数

15

被引用文献数

7

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Time lag between the human motion and display output is a large obstacle that prevent the Head Coupled Display from application. A novel HMD "Reflex HMD", with time lag compensation was proposed and the preliminary prototype was constructed. The angular movement is measured by gyroscope in this HMD, modulates the driving signal for LCD panel, and shifts the viewport within the image supplied from the computer. The merit of this system is 1) the independece of computer platform, operating system, and application, 2) low cost and light weight, 3) precise compensation without causing additional delay. An experiment with the prototype ReflexHMD successfully showed that the delay of about 100 milliseconds (six frames) was decreased within one frame.