Abstract: A system for measuring the spatial distribution of the spectral emission of a measurement zone of an object, comprises: a first objective; means for selecting a portion of an image formed by the first objective; a diaphragm; light-dispersing means located in the vicinity of the diaphragm and allowing the light coming from the selecting means to be dispersed; and a second objective placed between the selecting means and the diaphragm, interacting with the first objective so that the aperture of the diaphragm is optically conjugated with the measurement zone by the first and second objectives. The first objective forms an image on a predetermined Fourier surface on which each point corresponds to an emission direction of the object for one particular wavelength. The selecting means have a selection surface shaped depending on the predetermined. Fourier surface, and the selecting means are placed on the predetermined Fourier surface.

Abstract: A device for measuring the space distribution of the spectral emission of an object. The device includes a first lens forming in its Fourier plane an image constituting the optical Fourier transform of a zone of the object, a second lens, a diaphragm conjugated optically with the zone by the first and second lenses, a mechanism for selecting a rectilinear portion of the image, a mechanism for dispersion of the light corresponding to this portion, and a sensor receiving the dispersed light. The spectral response of the zone, for each point of the portion, is determined by signals from the sensor. The device is applicable in particular to display screens.

Abstract: A system for measuring the luminance characteristics of objects, particularly objects with luminance dependent on the emission direction. This system includes an image sensor (8) and optical means (16, 18, 26, 28) provided to form the image of the totality of an object (6) on the sensor and to select, for each point of the object, with a view to forming the corresponding image-point, those of the light rays coming from this point of the object which propagate in a way approximately parallel to the optical axis (X) of the optical means.

Abstract: Apparatus comprising a measurement lens (2) forming the image of the Fourier transform (102) of the elementary area (101) in its image focal plane (Fi), a transfer lens (3) forming the image of the elementary area on a sensor (4) formed by detectors (4i,j), a diaphragm (5) for defining the aperture of the elementary area (101), and a processing circuit (6).The lens (2) producing the Fourier transform is associated with a field lens (10), the combination of these two means (2, 10) and of the circular aperture of diameter (d) which is defined by the diaphragm (5) making it possible, for any light beam having an angle of incidence .theta. and an angle of azimuth .psi., to select a measurement area of elliptical shape on the object (1) analyzed.

Abstract: Measurement device, for the colorimetric measurement of a display screen. The device includes a first lens which forms the image of the Fourier transform of the elementary surface to be measured. An optical system is used to form a second lens which projects the image of the transform onto a set of detectors. The second lens (10) comprises an input lens (11) after the image plan (Fi) of the first lens (1), a colour filter (12) formed by filters (12l) which are associated with each colour, an output lens (13), downstream of the colour filter (12) for focusing the beams onto the detectors (7i, J) of the sensor (7), and a processing circuit (18).