## 3 Experiments and Results
### Spectral, Luminance and Crosstalk Measurements  
It is generally known that the visible crosstalk is an overlay [22; 23; 24] by optical crosstalk due to the non-ideal spectral separation of the primary colors and electrical crosstalk due to the electrical coupling between the subpixels in the matrix. In our 3D display arrangement, the individual spectral fractions of prime-colors of both displays clearly differ. This leads to a visible color crosstalk and a reduction of light transmission for this demonstrator arrangement with Displays 1 + 2. In Table 2, the measured luminance of prime-colors of Displays 1 + 2 does not add up to the measured white-luminance. In Figure 10, the measured values of the whole display demonstrator are indicated by the left and the right graphs. Differences in the spectral distributions of Displays 1 and 2 reduce the intensity from 22% down to 12%. Thus, the combination of geometrical and spectral properties determines a transmission loss of approximately 88%. The measurement results of the single color arrangements will be explained by one example; the green-green combination with max. 10 cd/m\({}^{2}\). The white-green combination shows a reasonable amount of red intensity in the transmitted green area from 570-620 nm. This is caused by the broad green emission and filter characteristics of Display 2. The measured intensity transmitted through the demonstrator corresponds to only 7% of source luminance depicted in the green filled area in the right part of Figure 10. An explanation for the remaining 5% difference can be given by absorption losses and stray light in the polarizer, glass and filter layers of Display 2. Figure 10: **Left:** Display 1 with white spectrum and 90\({}^{\circ}\) tilted Display 2 with single prime-colors, visible crosstalk of blue in green; **Right:** spectral intensity of the green color primaries from both panels. Figure 9: Comparison of idealized subpixel structures (only green glows) on the left with the real subpixel structures on the right. (**a**) Display 1 (image display) and (**b**) Display 2 (color barrier). To analyze the color filter design for the two view setup of Section 2 shown in Figure 4, the measurement and the simulation use the same test pattern and parameter sets. The pixel pitches are input parameters from Table 1. From Figure 9, the pixel areas were used for the calculation of the luminance distribution. For their analysis, the first test pattern used only one emitting green column per stripe image. In addition, the measured green luminance of 146 cd/m\({}^{2}\) for Display 1 was used as the simulation input. The crosstalk values were determined from the angle-dependent luminance profile. The measured luminance distributions for the green single-columns (views 1 and 2, respectively left and right) are shown in Figure 11.  
Besides the main peaks, there are smaller peaks visible for the two views, where the minimum luminance is 0.2-0.3 cd/m\({}^{2}\). The measured ground level of about 0.2 cd/m\({}^{2}\) cannot be explained by the black level of the display. Its value of about 0.05 cd/m\({}^{2}\) was determined in a control measurement. The observed increase of the lower luminance values is mainly caused by electrical and optical crosstalk. In the process of electrical addressing, black subpixels with low intensity are slightly stimulated [25]. The causes for the different kinds of crosstalk cannot be precisely separated by measurement technology. Therefore, it is complex to consider this in the simulation [26]. Taking this into account, we have defined a parameter for the spectral residual light components that occur as a result of the unwanted electrical crosstalk. That parameter is valid for the complete display assembly. It is weighting the visible area fractions of the subpixels [17] and the maximum luminance of the subpixel colors in the simulation. These corrected values will be part of the calculation of luminance in the subpixel positions.