Screen reflections represent an important factor in the visibility and readability of displays under ambient light conditions. Initial efforts to quantify these reflection characteristics were attempted in early display standards. ISO 9241-305 reflection measurements were primarily designed for cathode ray tube displays exhibiting predominantly mirror and Lambertian reflection components. Modern displays exhibit haze scatter and diffraction, which are not sufficiently addressed by this standard. Recent work using the point spread function method now enables high-resolution reflection characterization and, together with ISO TR 9241-313 and IEC 62977-2-8 methods, provides a framework for revising standards like ISO 9241-305 for current display technologies.

The point spread function method successfully separates specular and diffuse components of reflected glare from displays, with excellent agreement to previously reported annulus source and goniometric BRDF methods. Extracting haze profiles enables the prediction of ambient contrast with viewing direction. Of the three reflection components, haze has the greatest impact.

Analysis of the point‐spread function (PSF) yields the directional variations of scattered light with high resolution in the vicinity of the specular direction and now, finally, at reduced but sufficient resolution, also at off‐specular directions, thus providing a basis for the determination of a set of complete in‐plane BRD/BTD functions. This approach is applied to both identification and separation of mirror, haze and Lambertian reflection components which then can be classified into such components that are forwarding visual information to the observer (i. e. visual signal) and disturbing reflections (i.e. visual noise).

We apply analysis of the point‐spread function for evaluation of details of directional variations of display reflectance in the vicinity of the specular direction. This approach is used for obtaining more data on the effect of light sources with different apertures in the specular direction as a basis for ergonomic rating and for separation of disturbing display reflections from intended information‐carrying reflection components.

This paper summarizes the activities of ISO TC159 SC4 WG2 in the field of measurement of display reflectance as required for rating of ergonomic display performance since 1995, covering ISO 9241‐7, 13406‐2 and the series 9241‐30x. The shortcomings of the methods are introduced and improvements are proposed. We also summarize the state of measurement methods for reflective displays in general in IEC TC110.

This paper reviews specifications for (moving) image production and exchange (e.g. Rec.709, sRGB) and explains the importance of the involved nonlinear transfer functions, EOTFs, for the visual experience of the observer. The role of the inverse of the electro‐optical transfer function of the (legacy) CRT for transformation of camera signals into approximate perceptionally uniform scales is highlighted and the necessity of a non‐linear overall transfer characteristics is substantiated.

This paper reviews the approaches for prediction of flicker (a visual perception) from electronic displays starting with ISO 9241‐3:1992 and discusses their limitation to specific display technologies. The discrepancy between two popular methods for characterization of temporal luminance modulations (specified by JEITA and VESA) is analyzed and their consolidation is proposed. Results from recent acitivities in the field of "time‐modulated lighting systems" are introduced and their impact on the prediction of flicker from electronic displays is discussed.

This paper presents measurement procedures and results for state‐of‐the‐art OLED and LC‐display screens characterizing the stability of chromaticity, luminance and contrast with respect to viewing direction, electrical driving and ambient illumination. We present data concerning the reflective properties of both display technologies under hemispherical diffuse and directional (point‐source) illumination. The obstacles that have to be over‐come for realization of Rec.2020 and HDRI are introduced and discussed for both OLED and LC‐displays.

Non‐planar displays require a close look at the components involved in taking their measurements.

This paper compares three classes and six methods for evaluation of display sparkle, it provides experimental data and theoretical background for comparison of the procedures, the results and their reproducibility, the sensitivity of the approaches, and their advantages and drawbacks, in order to establish a solid basis for the ongoing standardization process.

New display technologies and recent trends may also enter the vehicle industry and correspondingly demand adaptations or new solutions for their standardized, i.e. comparable optical characterization. Amongst these, curved displays are most likely to be adopted because curvature opens up the possibility of actually integrating the displays into a car’s interior design. Here, we explain the basic differences between planar and cylindrical display screens during measurement of lateral and directional uniformity of luminance and chromaticity for both, imaging light measurement devices (ILMD) and spot measurement devices. The metrological differences also influence established uniformity analyses as described in the Black Mura standard “Uniformity Measurement Standard for Displays” of the German car industry. In addition, this paper describes the effects of alternative measurement approaches including light field imaging.

This paper explains and illustrates the meaning of luminance modulation (aka Michelson contrast) of visual display screens as basis for the perception of presented visual information and as basis for objective visual performance evaluation and rating of display screens according to the 2016 IDMS updates.

We introduce the combination of a high resolution RGB‐camera with an array spectroradiometer for fast and accurate evaluation of lateral variations of chromaticity and luminance in the field of display metrology. The paper provides an analysis of the performance of this instrument when applied to colorimetric calibrations of state‐of‐the‐art computer display screens under the timing constraints of manufacturing lines.

Analysis of point-spread and line-spread functions is introduced as an approach to high-resolution scatter analysis of microstructured anti-glare layers in reflective mode of operation. This method is compared to conventional directional scanning (goniometric, conoscopic) by numerical modeling. Two different basic types of reflection scattering are introduced for the first time and the effect of the non-scattering side of anti-glare treated sheet materials is illustrated.

We introduce a new method for evaluation of sparkle of the combination of display and AG-layer by application of a weighting of the Fourier amplitudes of the random luminance modulations that are perceived as sparkle, according to the contrast sensitivity function of the human visual system. This new approach provides improved sensitivity to small sparkle variations, better control of parasitic low frequency components caused by non-uniformities of display illumination and an improved match to visual ratings with subtle differences in the low sparkle region.

SID Symposium Digest of Technical PapersVolume 47, Issue 1 p. 372-375 Book 1: Session 29: Advances in Automotive-Display Measurements 29-4: Image Blurring Induced by Scattering Anti-Glare Layers Michael E. Becker, Michael E. Becker Display-Messtechnik&Systeme, Rottenburg am Neckar -, GermanySearch for more papers by this authorThomas Fink, Thomas Fink Dr. Ing. h.c. F. Porsche AG, Stuttgart -, GermanySearch for more papers by this authorUdo Krüger, Udo Krüger TechnoTeam Bildverarbeitung GmbH, Ilmenau -, GermanySearch for more papers by this author Michael E. Becker, Michael E. Becker Display-Messtechnik&Systeme, Rottenburg am Neckar -, GermanySearch for more papers by this authorThomas Fink, Thomas Fink Dr. Ing. h.c. F. Porsche AG, Stuttgart -, GermanySearch for more papers by this authorUdo Krüger, Udo Krüger TechnoTeam Bildverarbeitung GmbH, Ilmenau -, GermanySearch for more papers by this author First published: 25 May 2016 https://doi.org/10.1002/sdtp.10685Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract We introduce the scattering-induced spreading of a narrow linear light source in transmission as an alternative method for characterization of image blurring induced by anti-glare layers. This novel method is compared to the recently presented concept of pixel crosstalk and to the transmissive scatter distribution function of anti-glare layers measured in two different ways. The reduction of transmittance modulation is presented as an additional method for characterization of image blur. The ranking of the results is compared to a generalized haze level of the AG samples as obtained from the transmittance distribution functions measured with two different methods. Citing Literature Volume47, Issue1Issue 1, San Francisco, CA, May 22–May 27, 2016May 2016Pages 372-375 RelatedInformation

AbstractThis article sketches the winding path of the art of measurement of LC‐display contrast and other visual properties versus viewing direction from the beginnings of LCD‐manufacturing in the 1970s until today. It describes two methods of directional scanning: conoscopy—an optical approach without moving parts—and gonioscopy, the motorized scanning of the range of directions of interest, and introduces their features and limitations and a range of instrumental implementations.

Four years after introduction of the first instrument for measurement of sparkle, the foundations have been reconsidered, and the pool of practical experience has been analyzed to provide a more detailed and complete picture of the subject matter. The following aspects are introduced and discussed: observation conditions and resulting requirements for imaging (sampling) and filtering, analysis of spatial periods and frequencies as a basis for filtering, spatial filtering concepts, sparkle in the frequency domain, sparkle evaluation based on analysis of single images and difference images, origins of unwanted sparkle components, scaling and offset in sparkle evaluation, and verification of the method.