1. Field of the Invention
The present invention relates to a sample detecting device, and more particularly, to a multi-angle and multi-channel detecting device.
2. Description of Related Art
Liquid crystal display panel detecting technique includes measurements of optical parameters such as chromaticity and brightness and plays an important role in the quality control of liquid crystal displays. In particular, with the increasing area of the display panels and the increasing processing speed, a fast and accurate detection has become more and more important. At present, conventional panel detecting devices can be classified into single-point Fourier optics panel measuring devices and multi-point beam-split panel measuring devices.
FIG. 1 shows a technique disclosed in U.S. Pat. No. 6,804,001. The disclosed device is a combination of Fourier optics theory and a beam-split spectrum image spectrum measuring structure. Light rays emitted from a test object 2 pass through lens sets 6, 8 to reach a slit 16. After passing through the slit 16, the light rays are projected by a beam-split element 18 onto a two-dimensional photodiode array sensor 14. The element 18 is composed of several filters with different bandpass ranges. In addition, the device further includes a rotating mechanism 40 capable of rotating the slit 16 with different angles, so as to obtain chromaticity and brightness of a test point at different view angles. If information regarding the chromaticity and brightness of the entire test object is required, moving the probe or the sample in two dimension manner and combining the chromaticity and the brightness information at every point of the sample are necessary. However, this device or method spends a lot of time for performing the measurement, and can hardly be implemented for an on-line detection.
FIG. 2 shows a multi-point beam-split panel measuring device disclosed in U.S. Pat. No. 5,751,420. The disclosed device uses a beam-split image spectrum measuring structure. A panel 42 is placed on a plane at a work distance from an image capturing lens. Light rays emitted from the panel are guided by the lens into a spectrum imaging device. After passing through the beam-split element inside the device, light signals of different wavelengths are projected onto different positions of a two-dimensional photodiode array sensor, so that the spectrum image corresponding to different positions in the field of view on the object side are obtained. Although this method can simultaneously obtain multiple channels of spectrum information to achieve a multi-point spectrum measuring effect, the measurement can only be carried out at one specified view angle at a time. Thus, a mechanism for providing an angular swing of the probe or of the panel is required when measurements at different view angles are performed. The rotating and positioning mechanism not only is complicated, but the motion itself is also time-consuming. As a result, although this method has been applied to on-line detection, it is not a fully satisfied solution.
The single-point measuring method is currently the most widely used panel inspection technique. To measure the entire panel, the probe or the panel has to be moved two-dimensionally and a lot of measuring time is required. Furthermore, in order to obtain optical parameters such as chromaticity and luminance at different view angles, the probe or the panel must be swung with a relative angle. However, the rotating and positioning mechanism can be quite complicated and the mechanical motion takes a lot of time. Now, there are still no rapid measuring devices that satisfy the VESA measuring standard, and thus an innovative measuring method is urgently required.