JP2812380B2 - Solid-state imaging device and driving method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state imaging device and a driving method thereof.

[0002]

2. Description of the Related Art In recent years, a solid-state imaging device has been widely used for an imaging unit of a video camera. In particular, a video camera for broadcasting has a light receiving section composed of a photoelectric conversion element and a vertical transfer section, and a storage section for storing signal charges, and vertically stores the signal charges stored in the photoelectric conversion elements during the storage time. A structure that can be transferred to the storage unit at high speed during the flyback period, a so-called frame interline transfer (Flame Interline Tra
2. Description of the Related Art A solid-state imaging device (hereinafter, referred to as an FIT structure) capable of using an nsfer (hereinafter, abbreviated as FIT) method is used.

Hereinafter, a conventional solid-state imaging device having an FIT structure will be described. FIG. 3 is a schematic plan view of a conventional solid-state imaging device. 3, reference numeral 31 denotes a light receiving unit; 32, a storage unit for temporarily storing signal charges from the light receiving unit 31; 33, a horizontal transfer unit for transferring signal charges to an output unit 34 described later; 34, an output unit; Photoelectric conversion elements arranged three-dimensionally, 3
Reference numeral 6 denotes a vertical transfer unit that transfers signal charges from the photoelectric conversion element 35 in the vertical direction, and 37 denotes a vertical transfer unit that forms the storage unit 32. A1 to A4 are terminals for supplying a drive pulse to a set of four transfer gates constituting the vertical transfer unit 36 of the light receiving unit 31, and B1 to B4 are terminals for supplying a drive pulse to the vertical transfer unit 37 of the storage unit 32. Terminals for supplying drive pulses to a pair of transfer gates are shown. In FIG. 3, the light receiving section 31 is shown as 6H × 6V for simplicity, but it is actually 94H × 6V.
8H × 486V, and the corresponding storage unit 32 is also 9
48Hx486V.

[0004] The operation of the solid-state imaging device configured as described above will be described below. The signal charges stored in the photoelectric conversion element 35 are read out to the vertical transfer unit 36 and transferred to the storage unit 32. At this time, four-phase driving pulses are applied to the vertical transfer unit 36 through the terminals A1 to A4.
Similarly, a four-phase drive pulse is applied to the storage section 32 through the terminals B1 to B4. After the signal charges stored in all the photoelectric conversion elements 35 are transferred to the storage unit 32 in this manner, the signal charges are read out to the horizontal transfer unit 33 for each stage of the vertical transfer unit 37 of the storage unit 32. , Horizontal transfer, output unit 3
4 is output.

[0005]

However, in the above-mentioned conventional configuration, for example, a video signal corresponding to a 4: 3 television system is transmitted from a solid-state imaging device corresponding to a 16: 9 pixel television system. Attempting to obtain such a signal requires a period for transferring and discharging unnecessary signals from the light receiving unit within the horizontal blanking period, so that the period for transferring signal charges from the storage unit to the horizontal transfer unit is shortened. Had issues.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a solid-state imaging device capable of transferring signal charges from a storage section to a horizontal transfer section at high speed.

[0007]

According to the present invention, there is provided a solid-state imaging device according to the present invention, wherein a final transfer gate of a vertical transfer unit of a storage unit or a plurality of transfer gates including at least a final transfer gate is other transfer gates. It has a configuration that can be driven independently of the gate.

[0008]

According to this configuration, since a high-speed transfer pulse can be independently applied to at least the final transfer gate of the storage section, unnecessary charges can be sufficiently swept out during the horizontal blanking period.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic plan view of a solid-state imaging device according to an embodiment of the present invention. Hereinafter, an example having a screen corresponding to a 16: 9 television system will be described. FIG.
1, 1 is a light receiving unit corresponding to the 16: 9 television system, 2 is a storage unit, 3 is a horizontal transfer unit, 4 is an output unit, 5
Is a first light receiving unit corresponding to a 4: 3 television system,
Reference numerals 6 and 7 denote second and third light receiving units which are not necessary for the 4: 3 television system, 8 denotes a first storage unit for accumulating signal charges of the 4: 3 television system, and 9 and 10 denote 4 units. : The second and third storage units A1 to A4 which are unnecessary for the television system of No. 3: terminals for supplying drive pulses to be supplied to the transfer gates of the vertical transfer unit (not shown) of the light receiving unit 1; B4 is a terminal for supplying a drive pulse to a transfer gate of a vertical transfer unit (not shown) of the storage unit 2, and L3 and L4 are high-speed transfer to the last transfer gate of the vertical transfer unit of the storage unit 2 and to the immediately preceding transfer gate. A terminal for supplying a pulse (which indicates a driving pulse applied to the transfer gate at the same time).

A driving method for extracting a video signal of the 4: 3 television system from the solid-state image pickup device configured as described above will be described below. In order to obtain such a video signal, the signal charges of the storage section 2 that are not required for the 4: 3 television system, that is, the signal charges of the second storage section 9 and the third storage section 10 are transferred to the horizontal blanking period. Must be read out to the horizontal transfer unit 2 and swept out.

FIG. 2 is a timing chart for explaining a method of driving the solid-state imaging device according to one embodiment of the present invention.
In FIG. 2, 21 is a horizontal blanking period, 22 is a first sweeping pulse, 23 is a driving pulse, 24 is a second sweeping pulse, and 25 is an OB for transferring a signal level of an optical black portion (hereinafter referred to as an OB portion). Transfer pulse, 26 is a time width that can be occupied by the drive pulse applied to the vertical transfer section of the storage section 2, 27 is an OB section fixed pulse for fixing the level of the OB section, and φHBI to φHB4 are the vertical transfer sections of the storage section 2. L3 is a drive pulse applied to the second-most transfer electrode of the vertical transfer unit of the storage unit 2, and L4 is applied to the last transfer electrode of the vertical transfer unit of the storage unit 2. It is a driving pulse.

Before the end of the horizontal blanking period 21, the first
Is applied to the horizontal transfer unit 3, and the second
Signal charges (unnecessary signals for the 4: 3 television system) in the storage unit 9 of the first embodiment. Next, horizontal blanking period 2
1 is completed, and the driving pulse 23 causes the first accumulation unit 8
(The signal charges required for the 4: 3 television system) are transferred through the horizontal transfer unit 3. Next, when the horizontal blanking period 21 is entered, first, signal charges (not necessary for the 4: 3 television system) of the third storage section 10 are swept out by the second sweeping pulse 24. Next, the level of the OB section is fixed by the OB section fixing pulse 37, and the OB signal is transferred by the OB section transfer pulse 25. ΦVB1 to φVB4 are applied to the vertical transfer unit of the storage unit 2 during the time width 26 in the horizontal blanking period 21 to transfer the signal charge from the light receiving unit 1, and the OB transfer pulse 25 and the first drive pulse During the period 22, the signal charges are transferred from the storage unit 2 to the horizontal transfer unit 3 by the high-speed drive pulses L3 and L4.

The driving pulses L3 and L4 for transferring the signal charges from the storage section 2 to the horizontal transfer section 3 are limited to the period during which the horizontal transfer section 3 is stopped, but the driving pulses φVB1 to φV
There is no problem if B4 is within the time width 26.

As described above, according to the driving method of this embodiment, unnecessary signal charges in the storage section can be transferred at high speed within a limited time, and the light receiving section corresponding to the 16: 9 television system is provided. Video signals corresponding to the 4: 3 television system can be easily extracted from the solid-state imaging device.

[0016]

As described above, the present invention has a structure in which the final transfer gate of the vertical transfer section of the storage section or a plurality of transfer gates including at least the final transfer gate can be driven independently of the other transfer gates. An excellent image signal that can easily obtain a video signal corresponding to a television system having a second aspect ratio having a smaller width than the first aspect ratio from a solid-state imaging device corresponding to a television system having a first aspect ratio. A solid-state imaging device and a driving method thereof can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a solid-state imaging device according to an embodiment of the present invention.

FIG. 2 is a timing chart illustrating a driving method of a solid-state imaging device according to an embodiment of the present invention.

FIG. 3 is a schematic plan view of a conventional solid-state imaging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light-receiving part 2 Storage part 3 Horizontal transfer part 4 Output part

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yukio Saito 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Denshi Kogyo Co., Ltd. (72) Inventor Ryoichi Nagayoshi 1006 Kadoma, Kazuma, Osaka Prefecture Matsushita Denko Kogyo Co., Ltd. (72) Inventor Masayoshi Ozaki 1006, Kazuma Kadoma, Kadoma, Osaka Pref. References JP-A-58-10977 (JP, A) JP-A-5-219446 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 5/30-5/335

Claims (2)

(57) [Claims] 1. A light-receiving section having a photoelectric conversion element arranged in a matrix, a vertical transfer section for vertically transferring signal charges accumulated by the photoelectric conversion element, and a vertical transfer for temporarily storing the signal charge. A transfer unit that transfers the signal charges from the storage unit in the horizontal direction; and an output unit that outputs the signal charges from the horizontal transfer unit. A solid-state imaging device in which a final transfer gate of a unit or a plurality of transfer gates including at least the final transfer gate can be driven independently of other transfer gates. 2. A light-receiving section having a photoelectric conversion element arranged in a matrix, a vertical transfer section for vertically transferring signal charges accumulated in the photoelectric conversion element, and a vertical transfer for temporarily storing the signal charge. A transfer unit that transfers the signal charges from the storage unit in the horizontal direction; and an output unit that outputs the signal charges from the horizontal transfer unit. In a solid-state imaging device in which a plurality of transfer gates including at least the last transfer gate of the storage unit can be driven independently of other transfer gates, a plurality of transfer gates including at least the last transfer gate of the vertical transfer unit of the storage unit A driving method for a solid-state imaging device, wherein a driving pulse applied at a higher speed than a driving pulse applied to the other transfer gates is applied to the transfer gate.