Shutter Glasses Research Articles

Utility of stereoscopic displays for indirect-vision driving and robot teleoperation

The effectiveness of an active shutter-glasses stereoscopic display (SD) and a passive polarised SD was evaluated in a live robot-teleoperation task and a simulated indirect-vision driving task in various terrains. Overall, participants completed their tasks significantly faster with the SDs in three-dimensional (3D) mode than with the SDs in the baseline 2D mode. They also navigated more accurately with the SDs in 3D mode. When the effectiveness of the two types of SDs was examined separately, results showed that the active shutter-glasses SD resulted in faster responses and task completion times than the passive polarised SD, though most of the differences failed to reach statistical significance. Perceived workload when interacting with the two SD systems did not differ significantly between the active versus passive display types or between the 3D and 2D modes of operation; however, participants reported more severe discomfort after interacting with the passive polarised SD.

IR Sensor Synchronizing Active Shutter Glasses for 3D HDTV with Flexible Liquid Crystal Lenses

IR sensor synchronizing active shutter glasses for three-dimensional high definition television (3D HDTV) were developed using a flexible liquid crystal (FLC) lens. The FLC lens was made on a polycarbonate (PC) substrate using conventional liquid crystal display (LCD) processes. The flexible liquid crystal lens displayed a maximum transmission of 32% and total response time of 2.56 ms. The transmittance, the contrast ratio and the response time of the flexible liquid crystal lens were superior to those of glass liquid crystal lenses. Microcontroller unit and drivers were developed as part of a reception module with power supply for the IR sensor synchronizing active shutter glasses with the flexible liquid crystal lens prototypes. IR sensor synchronizing active shutter glasses for 3D HDTV with flexible liquid crystal lenses produced excellent 3D images viewing characteristics.

The Convergence Effect: Real and Virtual Encounters in Augmented Reality Art

The Convergence Effect: Real and Virtual Encounters in Augmented Reality Art

룩업 테이블 및 서브필드 맵핑을 이용한 계조 레벨 간 3D 크로스토크 저감 기술 구현

3D crosstalk is one of the disturbing things to recognize 3D images. This is caused by the phenomenon that input image for left eye is transferred at the right eye and right eye is transferred at the left eye because of the imperfect isolation by the device characteristics. In this paper, we review the 3D PDP (Plasma Display Panel) operation using active shutter glasses and crosstalk measurement method and investigate the major cause of 3D crosstalk and extend conventional 3D crosstalk using full white and full black image input to Gray-to-Gray (GtoG) 3D crosstalk. We suggest a specific method to reduce Gray-to-Gray 3D crosstalk by using Look up Table (LUT) and sub-field mapping in PDP. And then, we verify the method by measuring GtoG 3D crosstalk rate through specific test images and numerical results.

Interactive binocular treatment (I-BiT) for amblyopia: results of a pilot study of 3D shutter glasses system

A computer-based interactive binocular treatment system (I-BiT) for amblyopia has been developed, which utilises commercially available 3D 'shutter glasses'. The purpose of this pilot study was to report the effect of treatment on visual acuity (VA) in children with amblyopia. Thirty minutes of I-BiT treatment was given once weekly for 6 weeks. Treatment sessions consisted of playing a computer game and watching a DVD through the I-BiT system. VA was assessed at baseline, mid-treatment, at the end of treatment, and at 4 weeks post treatment. Standard summary statistics and an exploratory one-way analysis of variance (ANOVA) were performed. Ten patients were enrolled with strabismic, anisometropic, or mixed amblyopia. The mean age was 5.4 years. Nine patients (90%) completed the full course of I-BiT treatment with a mean improvement of 0.18 (SD=0.143). Six out of nine patients (67%) who completed the treatment showed a clinically significant improvement of 0.125 LogMAR units or more at follow-up. The exploratory one-way ANOVA showed an overall effect over time (F=7.95, P=0.01). No adverse effects were reported. This small, uncontrolled study has shown VA gains with 3 hours of I-BiT treatment. Although it is recognised that this pilot study had significant limitations-it was unblinded, uncontrolled, and too small to permit formal statistical analysis-these results suggest that further investigation of I-BiT treatment is worthwhile.

Flicker-free shutter glasses for full high-definition 3D viewing

Flicker-free shutter glasses for full high-definition 3D viewing

Dynamic exit pupil trackers for autostereoscopic displays

This paper describes the first demonstrations of two dynamic exit pupil (DEP) tracker techniques for autostereoscopic displays. The first DEP tracker forms an exit pupil pair for a single viewer in a defined space with low intraocular crosstalk using a pair of moving shutter glasses located within the optical system. A display prototype using the first DEP tracker is constructed from a pair of laser projectors, pupil-forming optics, moving shutter glasses at an intermediate pupil plane, an image relay lens, and a Gabor superlens based viewing screen. The left and right eye images are presented time-sequentially to a single viewer and seen as a 3D image without wearing glasses and allows the viewer to move within a region of 40 cm × 20 cm in the lateral plane, and 30 cm along the axial axis. The second DEP optics can move the exit pupil location dynamically in a much larger 3D space by using a custom spatial light modulator (SLM) forming an array of shutters. Simultaneous control of multiple exit pupils in both lateral and axial axes is demonstrated for the first time and provides a viewing volume with an axial extent of 0.6-3 m from the screen and within a lateral viewing angle of ± 20° for multiple viewers. This system has acceptable crosstalk (< 5%) between the stereo image pairs. In this novel version of the display the optical system is used as an advanced dynamic backlight for a liquid crystal display (LCD). This has advantages in terms of overall display size as there is no requirement for an intermediate image, and in image quality. This system has acceptable crosstalk (< 5%) between the stereo image pairs.

3D+2DTV

3D displays are increasingly popular in consumer and commercial applications. Many such displays show 3D images to viewers wearing special glasses, while showing an incomprehensible double image to viewers without glasses. We demonstrate a simple method that provides those with glasses a 3D experience, while viewers without glasses see a 2D image without artifacts. In addition to separate left and right images in each frame, we add a third image, invisible to those with glasses. In the combined view seen by those without glasses, this cancels the right image, leaving only the left. If the left and right images are of equal brightness, this approach results in low contrast for viewers without glasses. Allowing differential brightness between the left and right images improves 2D contrast. We observe experimentally that: (1) viewers without glasses prefer our 3D+2DTV to a standard 3DTV, (2) viewers with glasses maintain a strong 3D percept, even when one eye is significantly darker than the other, and (3) sequential-stereo display viewers with glasses experience a depth illusion caused by the Pulfrich effect, but it is small and innocuous. Our technique is applicable to displays using either active shutter glasses or passive glasses. Our prototype uses active shutter glasses and a polarizer.

Simultaneous 2D and 3D perception for stereoscopic displays based on polarized or active shutter glasses

Viewing stereoscopic 3D content is typically enabled either by using polarizing or active shutter glasses. In certain cases, some viewers may not wear viewing glasses and hence, it would be desirable to tune the stereoscopic 3D content so that it could be simultaneously watched with and without viewing glasses. In this paper we propose a video post-processing technique which enables good quality 3D and 2D perception of the same content. This is done through manipulation of one view by making it more similar to the other view to reduce the ghosting artifact perceived without viewing glasses while 3D perception is maintained. The proposed technique includes three steps: disparity selection, contrast adjustment, and low-pass filtering. The proposed approach was evaluated through an extensive series of subjective tests, which also revealed good adjustment parameters to suit viewing with and without viewing glasses with an acceptable 3D and 2D quality, respectively.

Fast response fringe-field switching mode liquid crystal development for shutter glass 3D

A type of fast response time (RT) liquid crystal (LC) was developed to adopt in fringe-field switching (FFS) mode for shutter glass 3D display device, the average gray to gray level (GTG) RT can reduce from 7.43 ms to 4.48 ms at a refreshing rate of 60 Hz, and the transmittance can increase by 15.4% compared with conventional LC based on the same cell gap. Meanwhile, the correlation among optical efficiency, correlative color temperature (CCT) of module and retardation of LC for FFS mode was studied. Transmittance is proportional to the retardation of LC; however, the CCT is inversely proportional to the retardation. The fast response LC can keep almost the original optical efficiency and CCT.

Simultaneous measurement of lens accommodation and convergence in natural and artificial 3D vision

AbstractRecent advances in 3D technology have been accompanied by increasing complaints of visual fatigue. The usual explanation for such fatigue is that accommodation and convergence are mismatched during stereoscopic vision.The aim of this study was to measure fixation distances between lens accommodation and convergence in young subjects while they viewed real objects and 3D video clips. Measurements were made using an original instrument. The 3D video clips were presented to subjects using a liquid crystal shutter glass system. The results showed that when viewing real objects, the diopter values of subjects' accommodation and convergence were similar and changed periodically. This measurement method was thus considered to be appropriate for the measurement of stereoscopic vision. We also investigated lens accommodation and convergence when subjects viewed 3D video clips. Both accommodation and convergence were found to move along with the virtual position of 3D video clips. Therefore, there was little discrepancy between accommodation and convergence during the viewing of 3D images.

Design and visualization of synthetic holograms for security applications

In this paper we present a software for the design and visualization of holographic elements containing full scale of visual effects. It enables to simulate an observation of the holographic elements under general conditions including different light sources with various spectral and coherence properties and various geometries of reconstruction. Furthermore, recent technologies offer interesting possibilities for the 3D visualization such as the 3D techniques based on shutter or polarization glasses, anaglyphs, etc. The presented software is compatible with the mentioned techniques and enables an application of the 3D hardware tools for visualization. The software package can be used not only for visualization of the existing designs, but also for a fine tuning of the spatial, kinetic, and color properties of the hologram. Moreover, the holograms containing all types of the 3D effects, general color mixing, kinetic behavior, diffractive cryptograms, etc. can be translated using the software directly to a high resolution micro-structure.

A method to remove residual signals in fibre optic luminescence dosimeters

Whenever a fibre optic is used to convey a light signal through a radiation field, it is likely that an unwanted background signal will arise from Cerenkov or fluorescent light which will contaminate the signal. In luminescence dosimetry of high energy beams, when a fibre optic is used to convey the signal from the radiation field to the detector, Cerenkov light is the dominant contributor to the background signal and must be corrected for. In this work, a novel method is demonstrated to separate the signal from the unwanted background. A remotely operated shutter is used to block the signal, allowing the residual background in the fibre optic to be quantified. This background is subtracted from the total measurement acquired in a subsequent irradiation, enabling the luminescence signal to be extracted. Two types of shutter mechanism are considered: an electro-mechanical device to intercept the light path and an LCD device to block the light by cross-polarization. Both shutters were characterized and incorporated into a fibre optic dosimetry system used to measure the radiation dose produced by external beam radiation linear accelerators. The dosimeter using each of the shutters in turn was exposed to a 6 MV photon beam to determine their performance, including the measurement of field size dependent output factors. The mechanical shutter determined the output factors to within 0.29% of those measured with an ionization chamber, whereas the LCD shutter gave results that deviated by up to 2.4%. The switching precision of both shutters was good with standard deviations of less than 0.25% and both were able to completely block the light signal when closed. The use of shutters could therefore be applied to any fibre optic based system to quantify and remove a reproducible background arising from any source including ambient, fluorescent and Cerenkov light.

Visual comfort in 2D/3D modes of glasses-type stereoscopic displays

In this study, we compared visual comfort in 2D/3D modes of the pattern retarder (PR) and shutter glasses (SG) stereoscopic displays by changing viewing factors and image contents. The viewing factors include ambient illuminance/monitor luminance/background luminance and image contents mainly are determined with different disparity limits. The degrees of 2D/3D visual comfort were investigated by using various combinations of ambient illuminance, monitor luminance, background luminance, and disparity limit. A series of psychological experiments were also performed to compare 2D and 3D viewing experiences for the passive PR and active SG stereoscopic displays and to discover more comfortable conditions under various variable combinations. The experiment results show that the various variable combinations affecting visual comfort in the passive PR and active SG stereoscopic displays were significantly different. Finally, we suggest more comfortable conditions of viewing 2D and 3D images for the PR and SG stereoscopic displays.

A Low-Power Fractional-Order Synchronizer for Syncless Time-Sequential Synchronization of 3-D TV Active Shutter Glasses

The 3-D TV active shutter glasses (SGs) technology requires the communication of the sync timing for time-sequential frame synchronization, in contrast to the syncless film-type patterned retarder approach. To advance our previous work based on the fractional-order timer, this paper proposes a fractional-order synchronizer, including an adaptive sync reconstructor (ASR) based on FRT for syncless frame synchronization. The FRT enables accurate synchronization regardless of sync-clock speed. The hybrid cooperation of FRT and ASR reduces the required frequency of communication of the sync packets and turns off the emitter on the TV side for perfect syncless operation. The implemented one-chip solution uses less than roughly 11% of the operating current of major commercial SG. The syncless SG technique also minimizes synchronization failure and 3-D vision crosstalk from interruption in sync packets.

快门眼镜式立体显示中闪烁的客观评价

快门眼镜式立体显示中闪烁的客观评价

Encoding of movement in near extrapersonal space in primate area VIP

Many neurons in the macaque ventral intraparietal area (VIP) are multimodal, i.e., they respond not only to visual but also to tactile, auditory and vestibular stimulation. Anatomical studies have shown distinct projections between area VIP and a region of premotor cortex controlling head movements. A specific function of area VIP could be to guide movements in order to head for and/or to avoid objects in near extrapersonal space. This behavioral role would require a consistent representation of visual motion within 3-D space and enhanced activity for nearby motion signals. Accordingly, in our present study we investigated whether neurons in area VIP are sensitive to moving visual stimuli containing depth signals from horizontal disparity. We recorded single unit activity from area VIP of two awake behaving monkeys (Macaca mulatta) fixating a central target on a projection screen. Sensitivity of neurons to horizontal disparity was assessed by presenting large field moving images (random dot fields) stereoscopically to the two eyes by means of LCD shutter goggles synchronized with the stimulus computer. During an individual trial, stimuli had one of seven different disparity values ranging from 3° uncrossed- (far) to 3° crossed- (near) disparity in 1° steps. Stimuli moved at constant speed in all simulated depth planes. Different disparity values were presented across trials in pseudo-randomized order. Sixty-one percent of the motion sensitive cells had a statistically significant selectivity for the horizontal disparity of the stimulus (p < 0.05, distribution free ANOVA). Seventy-five percent of them preferred crossed-disparity values, i.e., moving stimuli in near space, with the highest mean activity for the nearest stimulus. At the population level, preferred direction of visual stimulus motion was not affected by horizontal disparity. Thus, our findings are in agreement with the behavioral role of area VIP in the representation of movement in near extrapersonal space.

Mono-Stereo-Autostereo

In the past decade, surgery planning has changed significantly. The main reason is the improvements in computer graphical rendering power and display technology, which turned the plain graphics of the mid-1990s into interactive stereoscopic objects. To report our experiences with 2 virtual reality systems used for planning neurosurgical operations. A series of 208 operations were planned with the Dextroscope (Bracco AMT, Singapore) requiring the use of liquid crystal display shutter glasses. The participating neurosurgeons answered a questionnaire after the planning procedure and postoperatively. In a second prospective series of 33 patients, we used an autostereoscopic monitor system (MD20-3-D; Setred SA, Sweden) to plan intracranial operations. A questionnaire regarding the value of surgery planning was answered preoperatively and postoperatively. The Dextroscope could be integrated into daily surgical routine. Surgeons regarded their understanding of the pathoanatomical situation as improved, leading to enhanced intraoperative orientation and confidence compared with conventional planning. The autostereoscopic Setred system was regarded as helpful in establishing the surgical strategy and analyzing the pathoanatomical situation compared with conventional planning. Both systems were perceived as a backup in case of failure of the standard navigation system. Improvement of display and interaction techniques adds to the realism of the planning process and enables precise structural understanding preoperatively. This minimizes intraoperative guesswork and exploratory dissection. Autostereoscopic display techniques will further increase the value and acceptance of 3-dimensional planning and intraoperative navigation.

Preliminary evaluation of a virtual reality-based simulator for learning spinal anesthesia

Study ObjectiveTo evaluate the influence of a simulation-based program on the initial performance of dural puncture by medical interns, and to refine the design of simulator-based teaching and competence assessment. DesignProspective interventional study. SettingAcademic medical center. Subjects27 medical interns inexperienced in the technique of spinal anesthesia or dural puncture and within 12 months of graduating from medical school, were randomly assigned to a conventional or a simulator-based teaching course of spinal anesthesia: 13 were recruited to the Conventional Group (CG) and 14 to the Simulator Group (SG). MeasurementsA SenseGraphic Immersive workbench and a modified Phantom desktop with shutter glasses were used to create a teaching environment. Outcomes of teaching were assessed in two phases within three weeks of the teaching course: Phase I consisted of a written examination followed by assessment on the simulator. A global rating scale and a task-specific checklist were used. Phase II (for those participants for whom a suitable opportunity arose to perform spinal anesthesia under supervision within three wks of the teaching course) consisted of structured observation of clinical performance of the procedure in the operating room. Participants were assessed by independent, study-blinded experts. Student's two-tailed impaired t-tests were used to compare the parametric outcomes (P < 0.05 was considered significant). Main ResultsAll participants completed the written test successfully with no difference between groups. Ten participants from CG and 13 from SG completed the simulator-based testing performing similarly in terms of the global rating scale. Five participants in CG and 6 in SG proceeded to clinical testing. On the global rating scale, interns in SG scored higher than those in CG. They performed similarly according to the task-specific checklist. ConclusionsOverall, no difference was measured between those taught with traditional methods and those, by a simulator based program in regard to the performance of spinal anesthesia.

Visual fatigue and discomfort after stereoscopic display viewing

Different types of stereoscopic video displays have recently been introduced. We measured and compared visual fatigue and visual discomfort induced by viewing two different stereoscopic displays that either used the pattern retarder-spatial domain technology with linearly polarized three-dimensional technology or the circularly polarized three-dimensional technology using shutter glasses. During this observational cross-over study performed at two subsequent days, a video was watched by 30 subjects (age: 20-30 years). Half of the participants watched the screen with a pattern retard three-dimensional display at the first day and a shutter glasses three-dimensional display at the second day, and reverse. The study participants underwent a standardized interview on visual discomfort and fatigue, and a series of functional examinations prior to, and shortly after viewing the movie. Additionally, a subjective score for visual fatigue was given. Accommodative magnitude (right eye: p < 0.001; left eye: p = 0.01), accommodative facility (p = 0.008), near-point convergence break-up point (p = 0.007), near-point convergence recover point (p = 0.001), negative (p = 0.03) and positive (p = 0.001) relative accommodation were significantly smaller, and the visual fatigue score was significantly higher (1.65 ± 1.18 versus 1.20 ± 1.03; p = 0.02) after viewing the shutter glasses three-dimensional display than after viewing the pattern retard three-dimensional display. Stereoscopic viewing using pattern retard (polarized) three-dimensional displays as compared with stereoscopic viewing using shutter glasses three-dimensional displays resulted in significantly less visual fatigue as assessed subjectively, parallel to significantly better values of accommodation and convergence as measured objectively.