IEC 61947-1:2002 pdf download
IEC 61947-1:2002 pdf download.Electronic projection – Measurement and documentationof key performance criteria – Part 1: Fixed resolution projectors.
3.19
illuminance
quotient of a luminous flux incident on an element of the surface containing the point by the area of that element
Unit: lux (lx)
3.20
light source life expectancy
time that the light source can keep its projected light output as measured in this standard, higher than 50 % of the initial value when tested with a duty cycle of 2 h on and 15 mm off
3.21
liquid-crystal display (LCD)
display made of material the reflectance or transmittance of which changes when an electric field is applied
3.22
luminance
L
luminance in a given direction is the luminous intensity per unit of projected area of any surface, as viewed for that direction
Unit: candela per square metre (cd/rn2).
3.23
luminous flux
quantity derived from radiant flux by evaluating the radiation according to its action upon a selective receptor, the spectral sensitivity of which is defined by the standard 1931 CIE spectral luminance efficiency function for the photopic V(?) function
NOTE Quantity of light expressed in lumens, and directed in a given direction.
3.24
luminous intensity
luminous flux per unit solid angle emitted or reflected from a point source
Unit: candela
3.25
object
slide or transmissive/reflective image forming panel, such as an LCD, that is illuminated and imaged by the optics onto a viewing screen
3.26
peak angle
angle at which maximum luminance is observed
3.27
photometric units
units of light measurement based on the response of the average human observer. The response of the average human observer is defined by the 1931 CIE spectral luminance efficiency function for the photopic V(?) function
3.28
pixel
smallest element of a display space that can be independently assigned a colour or intensity
3.37
transmission
measure of the amount of light that is transmitted by an optical medium relative to the total amount of incident light
3.38
vertical lines
number of active lines in a picture
3.39
viewing angle/half gain
angle between the direction of maximal reflection and the direction where the luminance drops to 50 % of its value
NOTE This quantity should be measured in the centre of the viewing screen.
3.40
visible light
electromagnetic radiation to which the human observer is sensitive through the visual sensations that arise from the stimulation of the retina of the eye
NOTE The spectral range is typically considered to have a range of 380 nm to 780 nm (3 800 A to 7 800 A).
3.41
zoom lens
focusing lens that has a second, primary adjustment for focal length
NOTE This capability allows smaller or larger image sizes from a fixed projection distance. The zoom ratio is typically stated in a range of screen width/projection distance ratios, for example a 1:2 to 1:4 zoom lens could focus a 10 m or a 5 m wide image from a 20 m throw distance.
4 General requirements
This part of IEC 61947 is intended to specify a complete description of the product. In accordance with these intentions, a complete specification (see example in Annex D) shall be used in product descriptions. If a particular specified measurement was not performed, the complete specification shall include the text “not measured” or “data not available” under that measurement section.
NOTE The use of partial specifications in product descriptions is not recommended since many of the specified measurements are interrelated (e.g. resolution and light output).
All measurements and specifications shall conform to the following:
• the measurements of light output, visual resolution, and blanking found in this standard are interrelated and shall be measured and specified as a set;
• the parameters and measurement criteria specified in this document allow for a wide variety of equipment performance. Secondary, non-conforming specifications are permitted to allow flexibility for special features of various products and technologies, but shall be displayed in the same type face font and density at least 25 % smaller in size;
• a sample from normal production runs shall be used to establish the specifications. Results from measurements of pre-production and prototype units shall be identified as preliminary specifications;
• the sample units shall not be adjusted or enhanced beyond normal production parameters, especially in a way that would reduce the normal operating life of any component or of the entire display;
• all optical, electrical focus, and convergence controls shall be adjusted for the sharpest display over the largest possible percentage of the illuminated area, using appropriate patterns from an internal or external test generator as needed.