Fig. 1. Structure schematic of frame transfer area array CCD

Fig. 2. Timing sequence diagram of twice-frame-transfer exposure form. (a) Driven timing sequence; (b) software simulation result

Fig. 3. Illustrations of twice-frame-transfer process. (a) 1st frame transfer begins; (b) exposure begins; (c) 2nd frame transfer begins; (d) frame transferring; (e) horizontal readout

Fig. 4. Timing sequence simulation diagram of horizontal readout phase

Fig. 5. Structure diagram of imaging system

Fig. 6. Pictures of the devices. (a) Imaging system; (b) imaging circuit

Fig. 7. Average fitting result of exposure time and image pixel value

Fig. 8. Flame images taken in different exposure time. (a) 10 ms; (b) 500 ms

Fig. 9. Test result of SNR

Fig. 10. 3D and grayscale images of solid fuel flame captured by imaging system. (a) Dark background; (b) original image data; (c) dark background-substracted image data; (d) dark background-substracted grayscale image