Abstract: The invention pertains to a method and a device (60) for carrying out the quality control of an object (10). According to this method, at least a partial region of the object is scanned by means of at least one optical scanning system (40), and the gray scale values of the scanned points are recorded and stored. The gray scale values of at least part of the points are evaluated by an evaluation unit (64). In order to attain a faster display of the object (10), the invention proposes that at least part of the recorded gray scale values are stored in a storage unit (62), that at least one respective point is classified as being possibly defective or flawless based on its gray scale value in a filter unit (63) that is arranged in front of the evaluation unit (64), and that at least the points that were classified as being possibly defective are evaluated by the evaluation unit (64) based on the measured data stored in the storage unit (62).

Abstract: The invention relates to a process for the optical testing of a surface of an object, particularly a compact disc, in which the surface is illuminated by at least one light source and the light reflected and/or scattered by the surface is projected onto at least one substantially flat, light-sensitive element of a light-sensitive receiver. The receiver consists of several pixels in the form of a grid in the line direction and the space direction. In a test phase at least one actual image is generated that is compared with at least one desired image which was produced in a read-in phase. To produce an image of the surface with more information the invention provides that during the read-in phase and/or the test phase at least two images of the surface are taken and the image of the surface which is projected on the light-sensitive element is displaced by at least a fraction of the dimension of a pixel in each case in at least one direction with respect to the light-sensitive element.

Abstract: A process and device for the optical testing of a surface in which the surface can be illuminated substantially from above by at least one upper light and from the side by at least one lower light, at a sharp angle with respect to the surface. The light reflected and/or scattered by the surface is recorded in a test period by at least one light-sensitive receiver and at least one actual image which is compared with at least one desired image is produced. To permit an improved test provision is made for the surface to be recorded by the light-sensitive receiver at least twice during the test period. During the recording periods in question the surface is illuminated by an at least intermittent illumination from above and/or from the side in a different manner in order to obtain at least two actual images with different illumination of the surface.

Abstract: The invention pertains to a method and a device for carrying out the quality control of an object (10) that comprises at least one transparent layer (18). According to this method and this device, at least one light beam (41) of a light source (42) is projected onto the object (10) at an angle (.alpha.) and is received by at least one photosensitive receiver (53). According to the invention, it is proposed that the light beam (48) that emerges from the object be split before it is projected onto the first photosensitive receiver (53), with part of the light beam being deflected in the direction toward a second photosensitive receiver (62). This measure makes it possible to expose simultaneously two different photosensitive receivers (53, 62) so as to display different defects of an object (10).

Abstract: The invention pertains to a method and a device for carrying out the quality control of an object (10) that comprises at least one transparent layer (18). According to this method and this device, at least one light beam (41) of a light source (42) is projected onto the object (10) at an angle (.alpha.) and is received by at least one photosensitive receiver (53). According to the invention, it is proposed that the light beam that emerges from the object be split before it is projected onto the first photosensitive receiver (53), with part of the light beam being deflected in the direction toward a second photosensitive receiver (62). This measure makes it possible to expose simultaneously two different photosensitive receivers (53, 62) so as to display different defects of an object (10).