Kuo-Chung Huang | National Taiwan University (original) (raw)
Papers by Kuo-Chung Huang
Journal of the Society for Information Display, 2013
The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D disp... more The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D display. It can be designed based on simple geometric method and by considering the pitches of image display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction index of the cover glass, the angular behavior of the system becomes more realistic; however, the geometric method is difficult to be used. We propose a revised method for estimating the view distance and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view and shown that multiple DEPs make a circular curve around the center of the display. We prove the new concept by comparing the optical ray tracing calculations and optical measurement.
Input/Output and Imaging Technolgies II, 2000
Stereoscopic Displays and Applications XXIV, 2013
ABSTRACT There are several studies on estimating crosstalk of 3D displays. Crosstalk is an import... more ABSTRACT There are several studies on estimating crosstalk of 3D displays. Crosstalk is an important factor in determining image quality of stereoscopic display. In previous study, gray to gray crosstalk model has been modified. In this paper, we use six commercial stereoscopic displays including passive polarized glasses and active shutter glasses, both left and right eyes were measured by a luminance meter to verify the gray to gray crosstalk model and analyze the stability of the measurement data using our standard operating procedure (SOP). According to the SOP, we use simple statistical method to verify the repeatability of data. Experimental results indicate that our measurement system can be used to estimate the value of gray to gray crosstalk of stereoscopic display, the uncertainty below 0.8% for FPR display and 3% for shutter glasses display at 95% confidence level. These results, can be used as an important parameters in stereoscopic display visual quality, also can be used as a design feedback for engineer. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
SID Symposium Digest of Technical Papers, 2012
Viewing-zone (VZ) is an important research topic for stereoscopic displays. Although much researc... more Viewing-zone (VZ) is an important research topic for stereoscopic displays. Although much research has been done to date, more studies need to be conducted to ascertain the VZ criterion. In this paper, we proposed a novel evaluation method based on optical theory, simulation and experiment to figure out the VZ. We find that the VZ is no more diamond-shaped as the past studies reported.
For a 2D display, the higher the image contrast is, the better the visual quality will be. But th... more For a 2D display, the higher the image contrast is, the better the visual quality will be. But this is not necessarily correct
for a stereoscopic display. According to equation 2, the viewer’s crosstalk is proportional to the co-location contrast. That
means as the co-location contrast gets higher and higher, the ghost image phenomena will become worse and worse. It has
been mentioned in the previous paragraph that the co-location contrast and the single-view image contrast has a positive
relationship, i.e. increase in one value will also induce increase in the other, and vice versa. Under this fact, although the
image contrast is indeed proportional to the visual quality for monocular vision of the viewer, a higher image contrast will
on the contrary cause more crosstalk for a stereoscopic system. It is because the better image contrast will be easier to
induce “ghost image” due to the non-infinitesimal value of the system crosstalk. In another word, the image contrast could
be a conflict factor with the system crosstalk in a stereoscopic display system. The “viewer crosstalk” is then an overall
evaluation for the ghost image, and is easy to be interpreted due to the principle of binocular 3D display4.
J. SID, Aug 16, 2013
We propose a model to quantify the crosstalk phenomenon for stereoscopic and autostereoscopic dis... more We propose a model to quantify the crosstalk phenomenon for stereoscopic and autostereoscopic displays, separate crosstalk contributed from co-location image contrast (CIC) and
system crosstalk (SCT), introduce gray scale dependency of CIC, modify model for gray scale
dependency of SCT in active type 3D displays, and apply the model to derive the 3D luminance and SCT measurement formulas. The model might serve as a basis for the 3D metrology, and the results of this research should be of reference value to hardware makers and inspectors of stereoscopic and
autostereoscopic displays.
Proceeding of SPIE, 2003
The ghost-image issue induced by crosstalk in stereoscopic, especially autostereoscopic, display ... more The ghost-image issue induced by crosstalk in stereoscopic, especially autostereoscopic, display systems has been believed to be a major factor to jeopardize stereopsis. Nevertheless, it is found that in some cases the stereopsis remains effective even with serious crosstalk. In fact, many other factors, such as contrast ratio, disparity, and monocular cues of the images, play important roles in the fusion of stereo images. In this paper, we study the factors in an image that may affect stereo fusion, and provide a macroscopic point of view to get a reasonable criterion of system crosstalk. Both natural and computer-generated images are used for detailed evaluation. Image processing techniques are adopted to produce desired characteristics. The results of this research shall be of reference value to content makers of stereoscopic displays, in addition to their designers.
J. SID, Aug 16, 2013
The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D dis... more The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D
display. It can be designed based on simple geometric method and by considering the pitches of image
display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and
parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction
index of the cover glass, the angular behavior of the system becomes more realistic; however, the
geometric method is difficult to be used. We propose a revised method for estimating the view distance
and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view
and shown that multiple DEPs make a circular curve around the center of the display. We prove the new
concept by comparing the optical ray tracing calculations and optical measurement.
Optics Express, Feb 7, 2014
"Designated eye position (DEP) and viewing zone (VZ) are important optical parameters for designi... more "Designated eye position (DEP) and viewing zone (VZ) are important optical parameters for designing a two-view autostereoscopic display. Although much research has been done to date, little empirical evidence has been found to establish a direct relationship between design
and measurement. More rigorous studies and verifications to investigate DEP and to ascertain the VZ criterion will be valuable. We propose evaluation metrics based on equivalent luminance (EL) and binocular luminance (BL) to figure out DEP and VZ for a two-view autostereoscopic
display. Simulation and experimental results prove that our proposed evaluation metrics can be used to find the DEP and VZ accurately."
Optical Engineering, 2001
We describe an environment-friendly fabrication process for microretarders with a high contrast r... more We describe an environment-friendly fabrication process for microretarders with a high contrast ratio and well-defined stripe boundaries. It is shown that by accurately controlling the power, spot size, and scanning speed of a CO2 laser beam, the retardation property of a polymeric film can be tailored within a localized area without altering that of the untreated areas. The measurements and
Journal of Aerosol Science, 1996
Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curt... more Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curtains have been utilized to save running cost and improve the efficiency ofclean benches. In order to understand what extent push-pull air curtains can improve the performance of clean benches, two-dimensional numerical simulation is conducted in this paper to find the optimal flow pattern in clean benches. Result indicates that the optimal flow pattern occurs when the downward velocity through HEPA filters is 0.3 m s-i and the velocity from air curtain is 1.0 ms-i. In the optimal flow pattern, hazardous gases are prevented from leaking out of clean benches and particles of different sizes can be exhausted from clean benches by air curtains. Therefore, the objectives of cost saving, defect reduction and worker protection can be obtained.
A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes w... more A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes with alternating null and half-wave phase retardation states. An LCD with a microretarder attached on the front side can display good-quality stereoscopic images when viewed with polarization glasses. It is now the easiest and cheapest way to present stereoscopic images on a flat-panel display. However, the space caused by the glass between the retarder layer and the LC layer of the panel seriously limits the vertical view angle, which, in turn, limits the application of this technology. In this paper, a process for thin-film microretarder is developed using reactive liquid crystal. The material and the process are essentially compatible with current LC panel processes. Since the thin-film microretarder is to be fabricated in the cell of an LC panel, the retarder layer and the LC layer can be fabricated as close to each other as possible. A nearly unlimited 3D view angle can be achieved for the display.
The ghost image induced by System-Crosstalk (SCT) of 3D display, due to optical hardware imperfec... more The ghost image induced by System-Crosstalk (SCT) of 3D display, due to optical hardware imperfections, is the major factor to jeopardize stereopsis. The system crosstalk can be measured by optical measuring instrument and describes the optical leakage from the neighboring viewing zones. The amount of crosstalk reduces the ability of the viewer to fuse the stereo-images into 3D images. The Viewer-Crosstalk (VCT), combined with hardware and content issues, is an overall evaluation of the ghost image and can be easily interpreted based on the principle of binocular 3D display. The examination of different SCT values was carried out with a seven-grade subjective evaluation test. In our previous study, it was shown that many other factors, such as contrast ratio, disparity and monocular cues of the images, play important roles in the stereopsis. In this paper, we study the factors of stereo-images with different crosstalk levels that may affect stereopsis. For simulate the interference between stereo-images, digital image processing are employed to assign different levels of crosstalk to each other at properly specified disparity between images. Results of this research can provide valuable reference to the content makers and for the optimized design of 3D displays with minimum System Crosstalk.
Autostereoscopic displays have wider and wider applications, and optical quality evaluation is th... more Autostereoscopic displays have wider and wider applications, and optical quality evaluation is the bedrock for market development. Unfortunately, we lack the 3D display measurement standard (3D DMS), human factor and even standardized measurement instruments currently. Some studies reported the autostereoscopic display measurement using current optical measurement instrument such as luminance meter, CCD and conoscope1, 2, 3,4, but the problem now is how to verify those data? In this paper, we measured the optimal viewing distance (OVD), designated eye positions (DEP) and system-crosstalk of an autostereoscopic display and discussed some specific issues, like the affection of pupil size and measurement distance, method to find out the OVD, etc. which is usually met in 3D display measurement, and calculate the designated eye positions from the raw data using one-point method and two-point methods. The measurement was made by a luminance meter and the results were compared to the designed parameters.
A multiview autostereoscopic LCD display with a localized 2D/3D switching function is developed b... more A multiview autostereoscopic LCD display with a localized 2D/3D switching function is developed based on the actively switchable parallax barrier technology. This switchable barrier comprises of an electro-optically switchable liquid crystal (LC) and a microretarder. Polymer dispersed liquid crystal (PDLC) with switchable clear and diffusing states and twisted nematic liquid crystal (TNLC) with polarization switching function are used as switching devices. The microretarder is prepared by self-developed multibeam laser scanning process, which is clean, friendly to the environment, and easy for scale up and mass production. The influence factors on the image qualities of 3D displays based on LCD panel technology are analyzed and discussed. Some solutions have proposed to solve the commercial application issues.
Stereoscopic depth perception has been analyzed in many laboratory experiments since Wheatstone's... more Stereoscopic depth perception has been analyzed in many laboratory experiments since Wheatstone's (1838) discovery that disparity is a sufficient and compelling stimulus for the perception of depth with mirror-type stereo displays. In this paper, mirror-type stereo displays were used as the instrument to simulate the 3D image in the human factor experiment. It can be used to simulate the 9 view 3D display by image processing method with different multi-view crosstalk levels measured from luminance measurement device. The disparity of multi-view images to form stereopsis with depth perception is decided by the 9-view autostereoscopic 3D display that subject can properly fuse the image to get the proper visual depth. Computer graphic method applied for multi-view content rendering with shooting distance of 70 cm for each virtual camera. The distance between cameras is 5.6 cm with parallel capture to simulate the images accepted by human eyes. The experimental design was used for testing subjective evaluations based on the questionnaire, and ANOVA methods were used for analysis. Experimental variables of this human factor study for multi-view 3D display are five levels of crosstalk distribution from measured data, with or without shadow effects and perspective line shown within tested images. In addition, the result of acceptable system crosstalk level for multi-view stereoscopic display is between Level 4.7 and Level 5.9 in average for the four tested images.
Entertainment is usually considered an important application for stereoscopic display technologie... more Entertainment is usually considered an important application for stereoscopic display technologies. In order to provide more realistic and exciting VR effect, it is desirable to have as large screen as possible. However, the screen sizes of current autostereoscopic display technologies are limited by either the displaying panel or the optical components. In a government-sponsored project, we designed and fabricated a novel projection screen for autostereoscopic display. The screen consists of two layers of microretarder and a layer of polarization reserved diffuser. Both the screens and the projectors can be arrayed to build a large autostereoscopic display system. Curved or multi-plane screens are also possible. This kind of autostereoscopic display screen has the advantages of ease to scale up, low cost and no precise alignment between the projectors and the screen required. In this paper, the manufacture considerations of such a screen are studied and the experimental results are presented.
Optical Engineering, 2001
We describe an environment-friendly fabrication process for microretarders with a high contrast r... more We describe an environment-friendly fabrication process for microretarders with a high contrast ratio and well-defined stripe boundaries. It is shown that by accurately controlling the power, spot size, and scanning speed of a CO2 laser beam, the retardation property of a polymeric film can be tailored within a localized area without altering that of the untreated areas. The measurements and
Journal of Aerosol Science, 1996
Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curt... more Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curtains have been utilized to save running cost and improve the efficiency ofclean benches. In order to understand what extent push-pull air curtains can improve the performance of clean benches, two-dimensional numerical simulation is conducted in this paper to find the optimal flow pattern in clean benches. Result indicates that the optimal flow pattern occurs when the downward velocity through HEPA filters is 0.3 m s-i and the velocity from air curtain is 1.0 ms-i. In the optimal flow pattern, hazardous gases are prevented from leaking out of clean benches and particles of different sizes can be exhausted from clean benches by air curtains. Therefore, the objectives of cost saving, defect reduction and worker protection can be obtained.
A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes w... more A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes with alternating null and half-wave phase retardation states. An LCD with a microretarder attached on the front side can display good-quality stereoscopic images when viewed with polarization glasses. It is now the easiest and cheapest way to present stereoscopic images on a flat-panel display. However, the space caused by the glass between the retarder layer and the LC layer of the panel seriously limits the vertical view angle, which, in turn, limits the application of this technology. In this paper, a process for thin-film microretarder is developed using reactive liquid crystal. The material and the process are essentially compatible with current LC panel processes. Since the thin-film microretarder is to be fabricated in the cell of an LC panel, the retarder layer and the LC layer can be fabricated as close to each other as possible. A nearly unlimited 3D view angle can be achieved for the display.
Journal of the Society for Information Display, 2013
The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D disp... more The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D display. It can be designed based on simple geometric method and by considering the pitches of image display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction index of the cover glass, the angular behavior of the system becomes more realistic; however, the geometric method is difficult to be used. We propose a revised method for estimating the view distance and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view and shown that multiple DEPs make a circular curve around the center of the display. We prove the new concept by comparing the optical ray tracing calculations and optical measurement.
Input/Output and Imaging Technolgies II, 2000
Stereoscopic Displays and Applications XXIV, 2013
ABSTRACT There are several studies on estimating crosstalk of 3D displays. Crosstalk is an import... more ABSTRACT There are several studies on estimating crosstalk of 3D displays. Crosstalk is an important factor in determining image quality of stereoscopic display. In previous study, gray to gray crosstalk model has been modified. In this paper, we use six commercial stereoscopic displays including passive polarized glasses and active shutter glasses, both left and right eyes were measured by a luminance meter to verify the gray to gray crosstalk model and analyze the stability of the measurement data using our standard operating procedure (SOP). According to the SOP, we use simple statistical method to verify the repeatability of data. Experimental results indicate that our measurement system can be used to estimate the value of gray to gray crosstalk of stereoscopic display, the uncertainty below 0.8% for FPR display and 3% for shutter glasses display at 95% confidence level. These results, can be used as an important parameters in stereoscopic display visual quality, also can be used as a design feedback for engineer. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
SID Symposium Digest of Technical Papers, 2012
Viewing-zone (VZ) is an important research topic for stereoscopic displays. Although much researc... more Viewing-zone (VZ) is an important research topic for stereoscopic displays. Although much research has been done to date, more studies need to be conducted to ascertain the VZ criterion. In this paper, we proposed a novel evaluation method based on optical theory, simulation and experiment to figure out the VZ. We find that the VZ is no more diamond-shaped as the past studies reported.
For a 2D display, the higher the image contrast is, the better the visual quality will be. But th... more For a 2D display, the higher the image contrast is, the better the visual quality will be. But this is not necessarily correct
for a stereoscopic display. According to equation 2, the viewer’s crosstalk is proportional to the co-location contrast. That
means as the co-location contrast gets higher and higher, the ghost image phenomena will become worse and worse. It has
been mentioned in the previous paragraph that the co-location contrast and the single-view image contrast has a positive
relationship, i.e. increase in one value will also induce increase in the other, and vice versa. Under this fact, although the
image contrast is indeed proportional to the visual quality for monocular vision of the viewer, a higher image contrast will
on the contrary cause more crosstalk for a stereoscopic system. It is because the better image contrast will be easier to
induce “ghost image” due to the non-infinitesimal value of the system crosstalk. In another word, the image contrast could
be a conflict factor with the system crosstalk in a stereoscopic display system. The “viewer crosstalk” is then an overall
evaluation for the ghost image, and is easy to be interpreted due to the principle of binocular 3D display4.
J. SID, Aug 16, 2013
We propose a model to quantify the crosstalk phenomenon for stereoscopic and autostereoscopic dis... more We propose a model to quantify the crosstalk phenomenon for stereoscopic and autostereoscopic displays, separate crosstalk contributed from co-location image contrast (CIC) and
system crosstalk (SCT), introduce gray scale dependency of CIC, modify model for gray scale
dependency of SCT in active type 3D displays, and apply the model to derive the 3D luminance and SCT measurement formulas. The model might serve as a basis for the 3D metrology, and the results of this research should be of reference value to hardware makers and inspectors of stereoscopic and
autostereoscopic displays.
Proceeding of SPIE, 2003
The ghost-image issue induced by crosstalk in stereoscopic, especially autostereoscopic, display ... more The ghost-image issue induced by crosstalk in stereoscopic, especially autostereoscopic, display systems has been believed to be a major factor to jeopardize stereopsis. Nevertheless, it is found that in some cases the stereopsis remains effective even with serious crosstalk. In fact, many other factors, such as contrast ratio, disparity, and monocular cues of the images, play important roles in the fusion of stereo images. In this paper, we study the factors in an image that may affect stereo fusion, and provide a macroscopic point of view to get a reasonable criterion of system crosstalk. Both natural and computer-generated images are used for detailed evaluation. Image processing techniques are adopted to produce desired characteristics. The results of this research shall be of reference value to content makers of stereoscopic displays, in addition to their designers.
J. SID, Aug 16, 2013
The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D dis... more The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D
display. It can be designed based on simple geometric method and by considering the pitches of image
display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and
parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction
index of the cover glass, the angular behavior of the system becomes more realistic; however, the
geometric method is difficult to be used. We propose a revised method for estimating the view distance
and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view
and shown that multiple DEPs make a circular curve around the center of the display. We prove the new
concept by comparing the optical ray tracing calculations and optical measurement.
Optics Express, Feb 7, 2014
"Designated eye position (DEP) and viewing zone (VZ) are important optical parameters for designi... more "Designated eye position (DEP) and viewing zone (VZ) are important optical parameters for designing a two-view autostereoscopic display. Although much research has been done to date, little empirical evidence has been found to establish a direct relationship between design
and measurement. More rigorous studies and verifications to investigate DEP and to ascertain the VZ criterion will be valuable. We propose evaluation metrics based on equivalent luminance (EL) and binocular luminance (BL) to figure out DEP and VZ for a two-view autostereoscopic
display. Simulation and experimental results prove that our proposed evaluation metrics can be used to find the DEP and VZ accurately."
Optical Engineering, 2001
We describe an environment-friendly fabrication process for microretarders with a high contrast r... more We describe an environment-friendly fabrication process for microretarders with a high contrast ratio and well-defined stripe boundaries. It is shown that by accurately controlling the power, spot size, and scanning speed of a CO2 laser beam, the retardation property of a polymeric film can be tailored within a localized area without altering that of the untreated areas. The measurements and
Journal of Aerosol Science, 1996
Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curt... more Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curtains have been utilized to save running cost and improve the efficiency ofclean benches. In order to understand what extent push-pull air curtains can improve the performance of clean benches, two-dimensional numerical simulation is conducted in this paper to find the optimal flow pattern in clean benches. Result indicates that the optimal flow pattern occurs when the downward velocity through HEPA filters is 0.3 m s-i and the velocity from air curtain is 1.0 ms-i. In the optimal flow pattern, hazardous gases are prevented from leaking out of clean benches and particles of different sizes can be exhausted from clean benches by air curtains. Therefore, the objectives of cost saving, defect reduction and worker protection can be obtained.
A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes w... more A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes with alternating null and half-wave phase retardation states. An LCD with a microretarder attached on the front side can display good-quality stereoscopic images when viewed with polarization glasses. It is now the easiest and cheapest way to present stereoscopic images on a flat-panel display. However, the space caused by the glass between the retarder layer and the LC layer of the panel seriously limits the vertical view angle, which, in turn, limits the application of this technology. In this paper, a process for thin-film microretarder is developed using reactive liquid crystal. The material and the process are essentially compatible with current LC panel processes. Since the thin-film microretarder is to be fabricated in the cell of an LC panel, the retarder layer and the LC layer can be fabricated as close to each other as possible. A nearly unlimited 3D view angle can be achieved for the display.
The ghost image induced by System-Crosstalk (SCT) of 3D display, due to optical hardware imperfec... more The ghost image induced by System-Crosstalk (SCT) of 3D display, due to optical hardware imperfections, is the major factor to jeopardize stereopsis. The system crosstalk can be measured by optical measuring instrument and describes the optical leakage from the neighboring viewing zones. The amount of crosstalk reduces the ability of the viewer to fuse the stereo-images into 3D images. The Viewer-Crosstalk (VCT), combined with hardware and content issues, is an overall evaluation of the ghost image and can be easily interpreted based on the principle of binocular 3D display. The examination of different SCT values was carried out with a seven-grade subjective evaluation test. In our previous study, it was shown that many other factors, such as contrast ratio, disparity and monocular cues of the images, play important roles in the stereopsis. In this paper, we study the factors of stereo-images with different crosstalk levels that may affect stereopsis. For simulate the interference between stereo-images, digital image processing are employed to assign different levels of crosstalk to each other at properly specified disparity between images. Results of this research can provide valuable reference to the content makers and for the optimized design of 3D displays with minimum System Crosstalk.
Autostereoscopic displays have wider and wider applications, and optical quality evaluation is th... more Autostereoscopic displays have wider and wider applications, and optical quality evaluation is the bedrock for market development. Unfortunately, we lack the 3D display measurement standard (3D DMS), human factor and even standardized measurement instruments currently. Some studies reported the autostereoscopic display measurement using current optical measurement instrument such as luminance meter, CCD and conoscope1, 2, 3,4, but the problem now is how to verify those data? In this paper, we measured the optimal viewing distance (OVD), designated eye positions (DEP) and system-crosstalk of an autostereoscopic display and discussed some specific issues, like the affection of pupil size and measurement distance, method to find out the OVD, etc. which is usually met in 3D display measurement, and calculate the designated eye positions from the raw data using one-point method and two-point methods. The measurement was made by a luminance meter and the results were compared to the designed parameters.
A multiview autostereoscopic LCD display with a localized 2D/3D switching function is developed b... more A multiview autostereoscopic LCD display with a localized 2D/3D switching function is developed based on the actively switchable parallax barrier technology. This switchable barrier comprises of an electro-optically switchable liquid crystal (LC) and a microretarder. Polymer dispersed liquid crystal (PDLC) with switchable clear and diffusing states and twisted nematic liquid crystal (TNLC) with polarization switching function are used as switching devices. The microretarder is prepared by self-developed multibeam laser scanning process, which is clean, friendly to the environment, and easy for scale up and mass production. The influence factors on the image qualities of 3D displays based on LCD panel technology are analyzed and discussed. Some solutions have proposed to solve the commercial application issues.
Stereoscopic depth perception has been analyzed in many laboratory experiments since Wheatstone's... more Stereoscopic depth perception has been analyzed in many laboratory experiments since Wheatstone's (1838) discovery that disparity is a sufficient and compelling stimulus for the perception of depth with mirror-type stereo displays. In this paper, mirror-type stereo displays were used as the instrument to simulate the 3D image in the human factor experiment. It can be used to simulate the 9 view 3D display by image processing method with different multi-view crosstalk levels measured from luminance measurement device. The disparity of multi-view images to form stereopsis with depth perception is decided by the 9-view autostereoscopic 3D display that subject can properly fuse the image to get the proper visual depth. Computer graphic method applied for multi-view content rendering with shooting distance of 70 cm for each virtual camera. The distance between cameras is 5.6 cm with parallel capture to simulate the images accepted by human eyes. The experimental design was used for testing subjective evaluations based on the questionnaire, and ANOVA methods were used for analysis. Experimental variables of this human factor study for multi-view 3D display are five levels of crosstalk distribution from measured data, with or without shadow effects and perspective line shown within tested images. In addition, the result of acceptable system crosstalk level for multi-view stereoscopic display is between Level 4.7 and Level 5.9 in average for the four tested images.
Entertainment is usually considered an important application for stereoscopic display technologie... more Entertainment is usually considered an important application for stereoscopic display technologies. In order to provide more realistic and exciting VR effect, it is desirable to have as large screen as possible. However, the screen sizes of current autostereoscopic display technologies are limited by either the displaying panel or the optical components. In a government-sponsored project, we designed and fabricated a novel projection screen for autostereoscopic display. The screen consists of two layers of microretarder and a layer of polarization reserved diffuser. Both the screens and the projectors can be arrayed to build a large autostereoscopic display system. Curved or multi-plane screens are also possible. This kind of autostereoscopic display screen has the advantages of ease to scale up, low cost and no precise alignment between the projectors and the screen required. In this paper, the manufacture considerations of such a screen are studied and the experimental results are presented.
Optical Engineering, 2001
We describe an environment-friendly fabrication process for microretarders with a high contrast r... more We describe an environment-friendly fabrication process for microretarders with a high contrast ratio and well-defined stripe boundaries. It is shown that by accurately controlling the power, spot size, and scanning speed of a CO2 laser beam, the retardation property of a polymeric film can be tailored within a localized area without altering that of the untreated areas. The measurements and
Journal of Aerosol Science, 1996
Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curt... more Abstracts 657 velocity so as to waste large quantity of conditioned air. Thus, push-pull air curtains have been utilized to save running cost and improve the efficiency ofclean benches. In order to understand what extent push-pull air curtains can improve the performance of clean benches, two-dimensional numerical simulation is conducted in this paper to find the optimal flow pattern in clean benches. Result indicates that the optimal flow pattern occurs when the downward velocity through HEPA filters is 0.3 m s-i and the velocity from air curtain is 1.0 ms-i. In the optimal flow pattern, hazardous gases are prevented from leaking out of clean benches and particles of different sizes can be exhausted from clean benches by air curtains. Therefore, the objectives of cost saving, defect reduction and worker protection can be obtained.
A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes w... more A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes with alternating null and half-wave phase retardation states. An LCD with a microretarder attached on the front side can display good-quality stereoscopic images when viewed with polarization glasses. It is now the easiest and cheapest way to present stereoscopic images on a flat-panel display. However, the space caused by the glass between the retarder layer and the LC layer of the panel seriously limits the vertical view angle, which, in turn, limits the application of this technology. In this paper, a process for thin-film microretarder is developed using reactive liquid crystal. The material and the process are essentially compatible with current LC panel processes. Since the thin-film microretarder is to be fabricated in the cell of an LC panel, the retarder layer and the LC layer can be fabricated as close to each other as possible. A nearly unlimited 3D view angle can be achieved for the display.