The Industry’s First Digital Copier CCD Linear Sensor with RGB Adjacent 3-Line Plus Monochrome 1-Line 7600-Pixel Sensors ILX146K At the same time as demand for digitizing documents is increasing, there is also rapid progress being made in switching from analog to digital in copiers. The increasing performance in this area is remarkable. Due to this background, there is now strong demand for CCDs that can provide the performance to scan documents with high quality at even faster speeds. To respond to these needs, Sony has now developed the ILX146K CCD linear sensor in which the RGB sensor lines are directly adjacent to each other. Device Structure Figure 1 shows the ILX146K block diagram and figure 2 shows the structure of the vertical transfer block of the color RGB adjacent 3-line CCD. The color RGB adjacent 3-line sensor provides a vertical transfer gate adjacent to the blue sensor and reads out the charge collected at the green sensor. By carefully controlling the drive timing of the read gate and the vertical transfer gate, the readout charge is transferred to individual horizontal registers without any mixing of the blue and green charge. This allowed Sony to create an adjacent RGB sensor and made the following two features possible. V O I C The ILX146K adopts a CCD transfer structure that differs from conventional sensors. We came up with a lot of new ideas, for example, in the drive timing, and as a result were able to create a CCD linear sensor that features the 3 RGB lines being adjacent, which was previously unknown. This device is optimal for copiers and other scanner-based end products that need to operate at high speed. I strongly recommend that you consider this device. E Since the ILX146K also provides a monochrome (green) CCD, the ILX146K can support high-speed black-and-white scanning of documents and wide range of signal processing. Suppression of Incorrect Color Registration During Scanning Mechanical motion is required for document scanning using a CCD linear sensor. When spatial read errors (variations in the read position) in the scan direction occur during this mechanical motion, color registration errors occur. Since conventional CCD linear sensors have a wide spacing between the RGB sensors, the possibility for read errors to occur is high, especially during high-speed scanning. Since the ILX146K, in which the RGB sensors are adjacent, is resistant to the influence of spatial errors during scanning, color displacement is suppressed and it can support high-quality high-speed scanning. ■ Color RGB adjacent 3-line CCD + monochrome (green) CCD ■ High-speed transfer Maximum data rates: 100 MHz (monochrome) 150 MHz (color) High-Speed Transfer Maximum Data Rates: 100 MHz (Monochrome), 150 MHz (Color) Figure 3 shows the structure of the monochrome CCD vertical transfer block. While the color RGB adjacent 3-line CCD has a 2-stage horizontal register structure for each color, the monochrome CCD adopts a 4-stage structure in the horizontal registers for even faster processing. Sony applied further refinements to the color CCD vertical transfer structure, to allow the signal charge to be divided among 4 horizontal registers. The signal charge transferred by the horizontal registers is transferred a maximum distance of 7 cm (9.325 µm × 7,500 pixels) to the charge to voltage conversion block. Each of these horizontal registers has a maximum transfer rate of 25 MHz. This allows the ILX146K to achieve a maximum data rate of 100 MHz. φH1-M φH2-M 44 43 φHDG-M 45 Driver φHH3-M 46 Driver φHH2-M 54 Driver φHH1-M 53 Driver φCHG2 4 φCHG-M 3 φROG-M 52 VDD GND VL GND φH1-M φH2-M φLH-M φRS-M 48 39 47 51 42 41 40 29 Driver Driver CCD register (G-3) Output circuit 37 VOUT-G3 CCD register (G-1) Output circuit 36 VOUT-G1 CCD register (G-4) Output circuit 21 VOUT-G4 CCD register (G-2) ROG/CHG/CHG2 Sensor (G-M) Output circuit 22 VOUT-G2 Monochrome green sensor Driver 56 φH2 55 φH1 φH2 28 φH1 27 VOUT-RE 50 Output circuit Output circuit CCD register (R-EVEN) VOUT-GO 6 Output circuit CCD register (R-ODD) ROG/CHG Sensor (R) Sensor (G) Sensor (B) ROG/CHG CCD register (G-ODD) VOUT-GE 7 Output circuit CCD register (G-EVEN) VOUT-BO 8 Output circuit CCD register (B-ODD) VOUT-BE 9 Output circuit CCD register (B-EVEN) VOUT-RO 49 1 12 14 13 φRS φLH φH1 φH2 20 11 19 35 VDD GND VL GND Driver 24 φROG Driver Driver 33 φV1 32 φV2 31 φCHG Driver 25 φHH1 Driver 26 φHH2 Driver 18 φHH3 Driver 17 φHDG Driver Color RGB adjacent 3-line linear sensor 16 15 φH1 φH2 ■ Figure 1 Block Diagram ■ Table 1 Device Structure Horizontal register Item Number of effective pixels Horizontal register Read gate Vertical transfer gate Sensor (Red) Sensor (Red) Sensor (Red) Sensor (Red) Sensor (Red) Sensor (Green) Sensor (Green) Sensor (Green) Sensor (Green) Sensor (Green) Sensor (Blue) Sensor (Blue) Sensor (Blue) Sensor (Blue) Pixel size Sensor structure Number of outputs Sensor (Blue) Supply voltage Resolution Package Read gate Horizontal register Horizontal register ILX146K 30,400 pixels (7,600 pixels × 4) 9.325 µm (H) × 9.325 µm (V) (9.325 µm pitch) 3 adjacent RGB lines + 1 G line 10 outputs (2 outputs each for the color RGB lines) (4 green outputs for the monochrome line) Dual power supply: 10 V and -3 V 600 DPI (A3) 56-pin DIP (Cer-DIP) Vertical register Horizontal register Horizontal register ■ Figure 2 Vertical Transfer Block Structure (Color RGB adjacent 3-line CCD) Horizontal register Vertical register Horizontal register Horizontal register Horizontal register Read gate Green sensor (monochrome) ■ Figure 3 Vertical Transfer Block Structure (Monochrome CCD) ■ Table 2 Electrooptical Characteristics Ta = 25°C, VDD = 10 V, VL = –3 V, fφRS = 25 MHz, input clock = 5 Vp-p, light source = 3200K, using a CM-500S (t = 1.0 mm) IR cut filter. Typ. Unit Item 10 R 15 G V/(lx · s) Sensitivity 7.5 B 14.5 Monochrome % 10 Sensitivity nonuniformity % 10 Adjacent pixel difference V 1.2 (Min.) Saturated output voltage mV 0.4 Dark voltage average mV 1.0 Dark signal nonuniformity % 0.1 Image lag mA 125 Current consumption 50 Maximum operating R, G, B MHz/color frequency 100 Monochrome