Researcher:
Hedili, M. Kıvanç

Profile Picture
ORCID

Job Title

Master Student

First Name

M. Kıvanç

Last Name

Hedili

Name

Name Variants

Hedili, M. Kıvanç

Email Address

Birth Date

Filters

2011 - 202010

Advanced Search

Filter by

Settings

Researcher Of Publications: search.filters.isAuthorOfPublication.b51079b3-928f-4f58-8c70-a81b1930f503

Search Results

Now showing 1 - 10 of 10
  • Placeholder
    PublicationMetadata only
    MEMS scanners and emerging 3D and interactive Augmented Reality display applications
    (Institute of Electrical and Electronics Engineers (IEEE), 2013) Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; N/A; Ürey, Hakan; Holmstrom, Sven; Baran, Utku; Akşit, Kaan; Hedili, M. Kıvanç; Eldeş, Osman; Faculty Member; Researcher; Master Student; PhD Student; Master Student; Master Student; Department of Electrical and Electronics Engineering; College of Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; 8579; N/A; N/A; N/A; N/A; N/A
    MEMS scanners have advanced rapidly during the last 20 years thanks to the excellent mechanical and optical properties offered by silicon. They have been used in various display and imaging products. The performance of high resolution and high frequency MEMS laser scanners is close to meeting the demands of full HD displays (120 million pixels per second). Important performance metrics and the performance of various electromagnetic, electrostatic, and piezoelectric actuated MEMS scanners developed in our group are reviewed and recent improvements in the piezoelectric actuated resonant MEMS scanner is presented. Second part of the paper is about some of the emerging 3D and interactive Augmented-Reality display applications enabled by pico-projectors using MEMS scanners. Those technologies are expected to play an important role in the future of human-computer interface.
  • Placeholder
    PublicationMetadata only
    Paper no 15.1: augmented reality and 3D displays using pico-projectors
    (Blackwell Publishing, 2013) N/A; N/A; N/A; Department of Electrical and Electronics Engineering; Akşit, Kaan; Eldeş, Osman; Hedili, M. Kıvanç; Ürey, Hakan; PhD Student; Master Student; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; 8579
    Pico-projectors based on ME MS scanners and RGB lasers provide a powerful platform for not only mobile projectors but also for various 3D display architectures and augmented reality. First part of the paper discusses two recently developed 3D display techniques: a stereoscopic display using only one pico-projector passive polarized glasses and an autostereoscopic multiuser multiview display using an array of pico-projectors. Second part of the paper discusses various augmented reality applications enabled by a pico-projector and a special micro-optical screen. Those technologies can be expected to play an important role in the future of human-computer interface.
  • Placeholder
    PublicationMetadata only
    Next generation augmented reality displays
    (IEEE, 2018) N/A; N/A; N/A; N/A; N/A; Department of Electrical and Electronics Engineering; Hedili, M. Kıvanç; Ulusoy, Erdem; Kazempourradi, Seyedmahdi; Soomro, Shoaib Rehman; Ürey, Hakan; Master Student; Researcher; Researcher; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; N/A; N/A; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; N/A; 8579
    Wearable AR/VR displays have a long history and earlier efforts failed due to various limitations. Advances in various sensors, optical technologies, and computing technologies renewed the interest in this area. AR glasses can be the new computing platform and potentially replace smart phones but there are some challenges ahead. We have been working on various wearable display architectures and here we summarize our efforts on laser MEMS scanning displays, head-mounted projectors, and holographic near-eye displays
  • Placeholder
    PublicationMetadata only
    FR4 electromagnetic scanner based fourier transform spectrometer
    (ASME, 2011) Department of Electrical and Electronics Engineering; N/A; Department of Electrical and Electronics Engineering; N/A; Ürey, Hakan; Baran, Utku; Ölçer, Selim; Hedili, M. Kıvanç; Faculty Member; Master Student; Other; Master Student; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; 8579; N/A; N/A; N/A
    Fourier transform spectrometers require an interferometric optical setup, where a precisely controlled motion of a mirror on a moving stage and a reference mirror are required. FR4, a common printed circuit board substrate, and the standard PCB technology is used to develop a simple gimbaled scanner structure with high precision to implement into a low-cost and viable Fourier Transform Spectrometer. On top of the corner cube reflector based tilt-insensitive setup, magnetic actuation optimization using twin opposing magnets solution is found to be helpful to enhance interference data. Large Lorentz force is generated for out-ofplane deflection while the torsional motion of the scanner is restricted. ±162.8um out-ofplane translation at 149 Hz resonance is realized with torsion effect deteriorated result which corresponds to <1nm spectral resolution at visible wavelengths.
  • Thumbnail Image
    PublicationOpen Access
    Light-efficient augmented reality display with steerable eyebox
    (Optical Society of America (OSA), 2019) Department of Electrical and Electronics Engineering; Hedili, M. Kıvanç; Soner, Burak; Ulusoy, Erdem; Ürey, Hakan; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; N/A; N/A; 111927; 8579
    We present a novel head-mounted display setup that uses the pinhole imaging principle coupled with a low-latency dynamic pupil follower. A transmissive LCD is illuminated by a single LED backlight. LED illumination is focused onto the viewer's pupil to form an eyebox smaller than the average human pupil, thereby creating a pinhole display effect where objects at all distances appear in focus. Since nearly all the light is directed to the viewer's pupil, a single low-power LED for each primary color with 0.42 lumens total output is sufficient to create a bright and full-color display of 360 cd/m(2) luminance. In order to follow the viewer's pupil, the eyebox needs to be steerable. We achieved a dynamic eyebox using an array of LEDs that is coupled with a real-time pupil tracker. The entire system is operated at 11 msec motion-to-photon latency, which meets the demanding requirements of the real-time pupil follower system. Experimental results effectively demonstrated our head-mounted pinhole display with 37 degrees FOV and very high light efficiency, equipped with a pupil follower with low motion-to-photon latency.
  • Thumbnail Image
    PublicationOpen Access
    Microstructured head-up display screen for automotive applications
    (Society of Photo-optical Instrumentation Engineers (SPIE), 2012) Freeman, Mark O.; Department of Electrical and Electronics Engineering; Hedili, M. Kıvanç; Ürey, Hakan; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 8579
    A novel see-through screen is developed for automobiles which reduces the size of the head-up display (HUD) unit considerably. The screen is illuminated by a laser scanning pico-projector and a real image is formed on the screen. The screen has thousands of hexagonally packed microlenses that are partially reflective and embedded in an index matched medium which provides very good see-through capability. Light reflected from the microlenses expand and form a hexagon shaped viewing window. This system is called a direct projection HUD system as the pico projector projects directly onto the screen and forms a real image on it. The system is very compact and does not require any space under the dashboard, which saves on space for the car manufacturers, or allows it to be used immediately as an aftermarket HUD installed in any car.
  • Thumbnail Image
    PublicationOpen Access
    Next generation augmented reality displays
    (Institute of Electrical and Electronics Engineers (IEEE), 2018) Department of Electrical and Electronics Engineering; Ürey, Hakan; Soomro, Shoaib Rehman; Hedili, M. Kıvanç; Ulusoy, Erdem; Kazempourradi, Seyedmahdi; Faculty Member; Master Student; Department of Electrical and Electronics Engineering; College of Engineering; 8579; N/A; N/A; 111927; N/A
    Wearable AR/VR displays have a long history and earlier efforts failed due to various limitations. Advances in various sensors, optical technologies, and computing technologies renewed the interest in this area. AR glasses can be the new computing platform and potentially replace smart phones but there are some challenges ahead. We have been working on various wearable display architectures and here we summarize our efforts on laser MEMS scanning displays, head-mounted projectors, and holographic near-eye displays.
  • Thumbnail Image
    PublicationOpen Access
    Transmission characteristics of a bidirectional transparent screen based on reflective microlenses
    (Optical Society of America (OSA), 2013) Freeman, Mark O.; Department of Electrical and Electronics Engineering; Hedili, M. Kıvanç; Ürey, Hakan; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 8579
    A microlens array (MLA) based see-through, front projection screen, which can be used in direct projection head-up displays (HUD), color teleprompters and bidirectional interactive smart windows, is evaluated for various performance metrics in transmission mode. The screen structure consists of a partially reflective coated MLA buried between refractive-index-matched layers of epoxy as reported in Ref [1]. The reflected light is expanded by the MLA to create an eyebox for the user. The brightness gain of the screen can be varied by changing the numerical aperture of the microlenses. Thus, using high gain designs, a low-power projector coupled with the screen can produce high-brightness and even 3D images as the polarization is maintained at the screen. The impact of the partially reflective coatings on the transmitted light in terms of resolution and modulation transfer function associated with the screen is studied. A condition similar to the Rayleigh criteria for diffraction-limited imaging is discussed for the microlens arrays and the associated coating layers. The optical path difference between the light transmitted from the center and the edges of each microlens caused by the reflective layer coatings should not exceed lambda/4. Furthermore, the crosstalk between the front and rear projected images is found to be less than 1.3%.
  • Thumbnail Image
    PublicationOpen Access
    Foveated near-eye display using computational holography
    (Nature Publishing Group (NPG), 2020) Department of Electrical and Electronics Engineering; Cem, Ali; Hedili, M. Kıvanç; Ulusoy, Erdem; Ürey, Hakan; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 111927; 8579
    Holographic display is the only technology that can offer true 3D with all the required depth cues. Holographic head-worn displays (HWD) can provide continuous depth planes with the correct stereoscopic disparity for a comfortable 3D experience. Existing HWD approaches have small field-of-view (FOV) and small exit pupil size, which are limited by the spatial light modulator (SLM). Conventional holographic HWDs are limited to about 20° × 11° FOV using a 4 K SLM panel and have fixed FOV. We present a new optical architecture that can overcome those limitations and substantially extend the FOV supported by the SLM. Our architecture, which does not contain any moving parts, automatically follows the gaze of the viewer’s pupil. Moreover, it mimics human vision by providing varying resolution across the FOV resulting in better utilization of the available space-bandwidth product of the SLM. We propose a system that can provide 28° × 28° instantaneous FOV within an extended FOV (the field of view that is covered by steering the instantaneous FOV in space) of 60° × 40° using a 4 K SLM, effectively providing a total enhancement of > 3 × in instantaneous FOV area, > 10 × in extended FOV area and the space-bandwidth product. We demonstrated 20° × 20° instantaneous FOV and 40° × 20° extended FOV in the experiments.
  • Thumbnail Image
    PublicationOpen Access
    Microlens array-based high-gain screen design for direct projection head-up displays
    (Optical Society of America (OSA), 2013) Freeman, Mark O.; Department of Electrical and Electronics Engineering; Hedili, M. Kıvanç; Ürey, Hakan; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; N/A; 8579
    Head-up display (HUD) systems have been used in recent car models to provide essential information to the drivers while keeping their eyes on the road. Virtual image HUD systems have been the preferred method, but they have the drawback of requiring a large volume of space in order to accommodate the relay optics that creates the virtual image. This is especially significant as the desired field of view increases. Direct projection HUD systems have been developed with a separate stand-alone microlens array (MLA)-based transparent screen on the dashboard, offering a compact solution. In this paper, we propose a direct projection HUD system based on a unique, windshield-embedded see-through screen that uses minimal space under the dashboard, offering an elegant and compact solution to the HUD problem. The screen is based on MLAs with varying surface normal angles such that the light from the projector is directed to the viewer's eyes from all positions across the field of view. Varying tilts provide an efficient relay and high brightness even with a low-lumen output projector. The calculated screen gain is about 69 and the eyebox area is about 30 cm x 30 cm.