JPH03246969A - Solid-state image sensing element - Google Patents

Abstract

PURPOSE:To obtain a solid-state image sensing element whose resolution in the vertical direction is high by a method wherein photodiodes which form a pair on the right and left of a vertical charge transfer part are installed and color filters of different kinds are installed on the individual photodiodes. CONSTITUTION:Signal charges of two even-number-th photodiodes are read out under a transfer electrode V3; signal charges of two odd-number-th photodiodes are read out under a transfer electrode V1. That is to say, when a high voltage is applied to the electrode V3, the signal charges of one pair of even-number-th photodiodes on the right and left can be out at a vertical transfer part. When a high voltage is applied to the electrode V1, one pair of odd-number-the photodiodes at the right and left can be read out simultaneously. When color filters of G and Ye, G and Cy, Mg and Y or Mg and Cy are formed on the respective photodiodes which form one pair at the right and left, a signal which is equivalent to that which has added and read out signal charges of photodiodes arranged in two rows in the horizontal direction can be obtained from photodiodes which are arranged in one row in the horizontal direction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a solid-state image sensor, and in particular, to an HDTV (Ex
The present invention relates to an interline solid-state image sensor useful for a tended definition (TV) system.

[Prior Art] FIG. 2 shows a plan view of the imaging section of a conventional interline solid-state imaging device compatible with the interlaced system. In the same figure, PD 2++-2 to PD2n are photodiodes, and Vl (k ) ~ V3 (kl> and V2
(k) to V4(k) are vertical transfer electrodes, TG is a transfer gate integrated with the vertical transfer electrode, and C8 is an element isolation region.

In the illustrated example, the vertical charge transfer section is composed of four-phase CCDs, and vl (k) to 4 (k) constitute one transfer stage. On the other hand, the photodiode has 1
Two transfer electrodes are provided in each transfer stage, for example, transfer electrodes Vs
By applying a high voltage to (k), Vl (k1>, even-numbered photodiodes PD2ゎ, P
The signal charge of D2゜-2 can be read out to the vertical transfer section, and if a high voltage is applied to the transfer electrode ■□ (k-1), the signal charge of the odd-numbered photodiode PD2a-t can be read out. I can do it.

In order to realize colorization using a single plate with the conventional solid-state image sensor described above, green (hereinafter referred to as G), yellow (hereinafter referred to as Ye), and cyan (hereinafter referred to as cy) are required.
A magenta (hereinafter referred to as Mg) color filter,
For example, in the arrangement shown in FIG. 3, the photodiodes are arranged in one-to-one correspondence with each photodiode. When reading each field, the signal charges of the even-numbered and odd-numbered (or odd-numbered and even-numbered) photodiodes are read out and mixed into one vertical transfer electrode. For example, in the first field, a barrier is formed by applying a low voltage to the transfer electrodes V3 and 2 shown in FIG. ．． ．． PD2.
, read out the signal charges of the transfer chambers iV3, V4, Vt
Signal charges are added and mixed in the lower well. Furthermore, when reading out the second field, a barrier is formed under the transfer chamber triV4, and photodiodes PD2. ．． , PD2°-2 are read out and mixed.

In this way, in the second field, P of the previous field
D2. , PD2. , and the adjacent line PD21+
-2, P D 2n-3 signals can obtain intermediate information in the vertical direction.

[Problems to be Solved by the Invention] In the conventional method described above, since two pixels are added in the vertical direction and read out, the resolution in the vertical direction deteriorates (
For example, about 350 TVs in NTSC system). Therefore,
In recent years, in response to higher resolutions such as EDTV, a method has been developed in which the charges of each photodiode are read out independently without mixing them, such as using an even-numbered photodiode in the first field and an odd-numbered photodiode in the second field. Attention has been paid. According to this method, the vertical resolution is
For example, with the NTSC system, it can be improved to 400 to 45 OTV lines. However, in this case, G, Ye, Cy=
Since it is no longer possible to add and read out the signal charges of the photodiodes corresponding to each Mg color, the color has the same effect as when adding the signals of G and Ye, G and cy, or Mg and Ye, and Mg and cy. It is necessary to create a filter. However, such color filters have complicated spectral characteristics and cannot be easily realized. Also, is it possible to consider a method in which each photodiode is associated with two color filters of 1/2 color? This method has problems such as the area accuracy of the two colors and the color mixing of the two colors, and is technically difficult. It is extremely difficult.

[Means for Solving the Problems] The solid-state imaging device of the present invention has a plurality of vertical charge transfer sections, and a plurality of left and right photodiodes are arranged on both sides of each vertical charge transfer section. vs. provided.

Different types of color filters are arranged on each pair of photodiodes.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic plan view showing one embodiment of the present invention.

In the same figure, parts corresponding to those of the conventional example shown in FIG. 2 are given the same reference numerals. In this example, the second
As with the conventional example shown in the figure, the vertical transfer section is a 4-phase CCD.
The transfer chamber [i V s to V4 constitute one transfer stage. On the other hand, two pairs of photodiodes, that is, four photodiodes are arranged in one transfer stage.

In this embodiment, the signal charges of the two even-numbered photodiodes are read out under the transfer electrode 3, and the signal charges of the two odd-numbered photodiodes are read out under the transfer electrode V1. That is, by applying a high voltage to the transfer electrode (3), a pair of even-numbered left and right photodiodes (...;
PD2fi, PD2n.

The signal charges of PD211+2, PD211+2;...) can be simultaneously read out to the vertical transfer section, and by applying a high voltage to the transfer electrode V1, the signal charges of the odd-numbered left and right photodiodes (...;pD2 .-,,P
D2n-1.

...) charges can be read out simultaneously. Therefore, G is applied to each of the left and right photodiodes,
Ye; G, Cy; Mg-Ye or Mg, C
, y, then 1 in the horizontal direction.
By using the photodiodes arranged in a row, it is possible to obtain a signal equivalent to the case where the signal charges of the photodiodes arranged in two rows in the horizontal direction are added and read out in the conventional example.

[Effects of the Invention] As explained above, in the present invention, a pair of photodiodes are provided on the left and right sides of a vertical charge transfer section, and color filters of different types are placed on each photodiode. Therefore, according to the present invention, a solid-state imaging device with high resolution in the vertical direction can be provided without producing a color filter with complicated spectral characteristics and without requiring highly accurate processing.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a plan view showing an embodiment of the present invention.
FIG. 3, a plan view of the conventional example, is a diagram showing an example of the arrangement of color filters in the conventional example. C8...Element isolation region, TG...Transfer gate, PD 2n, 2~PD 21. ”Photodiode v2 (k-1) ~ v4 (k-1), V2
(k) to V4(k)...Vertical transfer electrode.

Claims (1)

[Claims] A plurality of vertical charge transfer sections, a horizontal charge transfer section disposed after the vertical charge transfer sections, a plurality of pairs of photodiodes disposed on both sides of each vertical charge transfer section, and the vertical charge transfer sections. A transfer gate is provided between the photodiode and the transfer gate is provided so as to read out the photoelectric conversion charge of the paired photodiode under the same transfer electrode of the vertical charge transfer section, and a transfer gate is provided on the paired photodiode. A solid-state image sensor comprising mutually different types of color filters.