High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight

The mid-air image is a very powerful method for presenting computer graphics in a real environment, but it cannot be used in bright locations owing to the decrease in brightness during the imaging process. Therefore, to form a mid-air image with a high-brightness light source, a square pyramidal mir...

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Main Authors: Naoya Koizumi, Koki Yuzurihara
Format: Article
Language:English
Published: MDPI AG 2020-08-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/10/17/5834
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author Naoya Koizumi
Koki Yuzurihara
author_facet Naoya Koizumi
Koki Yuzurihara
author_sort Naoya Koizumi
collection DOAJ
description The mid-air image is a very powerful method for presenting computer graphics in a real environment, but it cannot be used in bright locations owing to the decrease in brightness during the imaging process. Therefore, to form a mid-air image with a high-brightness light source, a square pyramidal mirror structure was investigated, and the sunlight concentration was simulated. We simulated the tilt angle and combination angle of the condenser as parameters to calculate the luminance of the surface of a transparent liquid crystal display. The light collector was installed at 55<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula> from the horizontal plane and mirror. A high level of illumination was obtained when these were laminated together at an angle of 70<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>. To select a suitable diffuser, we prototyped and measured the brightness of the mid-air image with an LED lamp to simulate sunlight in three settings: summer solstice, autumnal equinox, and winter solstice. The maximum luminance of the mid-air image displayed by collecting actual sunlight was estimated to be 998.6 <inline-formula><math display="inline"><semantics><mrow><mi>cd</mi><mo>/</mo><msup><mi mathvariant="normal">m</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula>. This is considerably higher than the maximum smartphone brightness to allow for outdoor viewing, and it can ensure fully compatible visibility.
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spelling doaj.art-47f1d27cbbff411e81771a64b0623d7b2023-11-20T11:04:46ZengMDPI AGApplied Sciences2076-34172020-08-011017583410.3390/app10175834High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing SunlightNaoya Koizumi0Koki Yuzurihara1Department of Infomatics, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, JapanDepartment of Infomatics, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, JapanThe mid-air image is a very powerful method for presenting computer graphics in a real environment, but it cannot be used in bright locations owing to the decrease in brightness during the imaging process. Therefore, to form a mid-air image with a high-brightness light source, a square pyramidal mirror structure was investigated, and the sunlight concentration was simulated. We simulated the tilt angle and combination angle of the condenser as parameters to calculate the luminance of the surface of a transparent liquid crystal display. The light collector was installed at 55<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula> from the horizontal plane and mirror. A high level of illumination was obtained when these were laminated together at an angle of 70<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>. To select a suitable diffuser, we prototyped and measured the brightness of the mid-air image with an LED lamp to simulate sunlight in three settings: summer solstice, autumnal equinox, and winter solstice. The maximum luminance of the mid-air image displayed by collecting actual sunlight was estimated to be 998.6 <inline-formula><math display="inline"><semantics><mrow><mi>cd</mi><mo>/</mo><msup><mi mathvariant="normal">m</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula>. This is considerably higher than the maximum smartphone brightness to allow for outdoor viewing, and it can ensure fully compatible visibility.https://www.mdpi.com/2076-3417/10/17/5834mid-air imagehigh luminanceliquid crystal display
spellingShingle Naoya Koizumi
Koki Yuzurihara
High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight
Applied Sciences
mid-air image
high luminance
liquid crystal display
title High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight
title_full High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight
title_fullStr High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight
title_full_unstemmed High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight
title_short High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight
title_sort high luminance mid air image display for outdoor viewing by focusing sunlight
topic mid-air image
high luminance
liquid crystal display
url https://www.mdpi.com/2076-3417/10/17/5834
work_keys_str_mv AT naoyakoizumi highluminancemidairimagedisplayforoutdoorviewingbyfocusingsunlight
AT kokiyuzurihara highluminancemidairimagedisplayforoutdoorviewingbyfocusingsunlight