Experimental Study of the Effects of Surround Brightness and Size on Visual Performance PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Experimental Study of the Effects of Surround Brightness and Size on Visual Performance PDF full book. Access full book title Experimental Study of the Effects of Surround Brightness and Size on Visual Performance by Fred H. Ireland. Download full books in PDF and EPUB format.
Author: Fred H. Ireland Publisher: ISBN: Category : Airplanes Languages : en Pages : 60
Book Description
A visual display must often be used in a setting where the surrounding visual field is brighter than the background area within the display. Such use violates a common human factors recommendation that the brightness of the display surround should be equal to, or slightly less than, that of the background in the display itself. The purpose of this experiment was to determine, quantitatively, the degradation in visibility due to high surround brightness and thus to provide useful data for the display system designer. Measurements were made of the target-to-background contrast required for each of 5 Ss to determine, with 50% accuracy, the orientation of a light Landolt ring target centered on a darker circular background. The target gap subtended 1.93 minutes of arc. Background angular subtense was varied from 5° to 45°, background brightness from 0.17 to 18.43 millilamberts and surround-to-background brightness ratio from 0:1 to 100:1. A uniform surround, independently variable in brightness with respect to the background, filled the rest of the visual field. The scene was viewed monocularly with natural pupil. The contrast limen was found to vary directly with surround-to-background brightness ratio for ratios greater than one. The variation with background size was smaller than predicted by an equation for integrating the effects of point sources of glare. An apparent tendency for a slight increase in limen as the surround-to-background ratio decreased from 1:1 to 0:1 was not statistically significant. Results are described by equations, and a procedure for their practical application is illustrated.
Author: Fred H. Ireland Publisher: ISBN: Category : Airplanes Languages : en Pages : 60
Book Description
A visual display must often be used in a setting where the surrounding visual field is brighter than the background area within the display. Such use violates a common human factors recommendation that the brightness of the display surround should be equal to, or slightly less than, that of the background in the display itself. The purpose of this experiment was to determine, quantitatively, the degradation in visibility due to high surround brightness and thus to provide useful data for the display system designer. Measurements were made of the target-to-background contrast required for each of 5 Ss to determine, with 50% accuracy, the orientation of a light Landolt ring target centered on a darker circular background. The target gap subtended 1.93 minutes of arc. Background angular subtense was varied from 5° to 45°, background brightness from 0.17 to 18.43 millilamberts and surround-to-background brightness ratio from 0:1 to 100:1. A uniform surround, independently variable in brightness with respect to the background, filled the rest of the visual field. The scene was viewed monocularly with natural pupil. The contrast limen was found to vary directly with surround-to-background brightness ratio for ratios greater than one. The variation with background size was smaller than predicted by an equation for integrating the effects of point sources of glare. An apparent tendency for a slight increase in limen as the surround-to-background ratio decreased from 1:1 to 0:1 was not statistically significant. Results are described by equations, and a procedure for their practical application is illustrated.
Author: Fred H. Ireland Publisher: ISBN: Category : Airplanes Languages : en Pages : 48
Book Description
A common human factors recommendation states that, for good target visibility, the area surrounding a display should not be brighter than the background area within the display. However, this recommendation must often be violated in applications where the surround brightness cannot be adequately controlled (e.g. in an airplane cockpit) and/or display technique limitations prevent use of high brightness backgrounds (e.g. with cathode ray tubes). This literature review was undertaken to see what has been discovered thus far concerning the effects on target visibility of specific parameters of a surround-to-background. Well over 100 documents were reviewed. Seventy-five annotated references to the more pertinent documents are contained in this report. Quantitative effects of pertinent parameters have been studied by numerous investigators. Results of studies using extended surrounds, rather than point sources, have not been sufficiently comprehensive or consistent to support quantitative generalizations in this area. Attempts have been made by Holladay and by Moon and Spencer to make quantitative predictions for the extended surround case on the basis of the more extensive body of data dealing with point source effects. However, several of the findings upon which their formulas are based have been contradicted by other findings cited in this report. (Author).
Author: Lawrence E. Tannas Publisher: Springer Science & Business Media ISBN: 9401170622 Category : Science Languages : en Pages : 487
Book Description
Flat-Panel Displays and CRTs, a review of electronic information display devices, is the first sys tematic and comprehensive coverage of the subject. It is intended to distill our wealth of knowledge of flat-panel displays and CRTs from their beginnings to the present state of the art. Historical perspective, theory of operation, and specific applications are all thoroughly covered. The field of display engineering is a multidisciplined technical pursuit with the result that its individual disciplines suffer from a lack of communications and limited perspective. Many previ ously developed standards for, and general understanding of, one technology are often inappro priate for another. Care has been taken here to document the old, incorporate the new, and emphasize commonalities. Criteria for performance have been standardized to enable an expert in one display technology, such as liquid crystals, to compare his device performance with that offered by another technology, such as electroluminescence. This book has been written with a second purpose in mind, to wit, to be the vehicle by means of which a new scientist or engineer can be introduced into the display society. It is organized to be tutorial for use in instructional situations. The first chapters begin with first principles and defini tions; the middle chapters set out requirements and criteria; and the last chapters give a complete description of each major technology.
Author: Fred H. Ireland
Author: Fred H. Ireland
Author: Fred H. Ireland
Author: Jared J. Collard
Author: 
Author: Patrick G. Meguire
Author: 
Author: 
Author: Lawrence E. Tannas
Author: 
Author: Gustave J. Rath