JPS6361832B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid-state image sensor in which a plurality of light-receiving elements are arranged both horizontally and vertically, and a mosaic color filter comprising filter elements arranged corresponding to the light-receiving elements. The present invention relates to a solid-state color imaging device.

There are many conventional solid-state color imaging devices. For example, JP-A-51-
No. 112228 "Color image sensor" has a green transmission filter (G filter) arranged at every other light receiving element position in both the horizontal and vertical directions as the mosaic color filter described above, and a red transmission filter (R filter). ), blue transmission filter (B
filters) are arranged alternately with G filters in every other row.

In this configuration, since the G filter exists at the highest frequency in both the horizontal and vertical directions compared to the R filter and the B filter, the resolution in both the horizontal and vertical directions is high.

However, solid-state imaging devices using this mosaic color filter have drawbacks such as low light utilization, poor resolution in diagonal directions, occurrence of moiré, and complicated signal processing circuits.

An object of the present invention is to provide a solid-state imaging device that eliminates the drawbacks of the solid-state imaging device described above.

In order to achieve this objective, in the present invention,
In a solid-state color imaging device including a plurality of light receiving elements arranged in horizontal and vertical directions and a mosaic color filter consisting of a filter element arranged corresponding to each of the light receiving elements, the mosaic color filter The four adjacent filter elements constituting the filter element include a first filter consisting of an all-color transmission filter, a first spectral region transmission filter, a second spectral region transmission filter, and a third spectral region transmission filter each having different transmission characteristics. a second filter selected from
The third and fourth filters are complementary color filters that transmit the transmitted component of the filter and have mutually different transmitted components, and in the horizontal direction,
The first filter and the second filter are
and the third filter and the fourth filter are adjacent to each other, and the mutual positions of the first and second filters and the third and fourth filters are adjacent to each other in the horizontal direction, The filter elements are arranged so as to alternate every two light receiving elements in the vertical direction.

FIG. 1 shows an embodiment of the present invention. In this embodiment, as shown in the figure, when focusing on four arbitrary adjacent light receiving elements arranged in 2 rows and 2 columns, the filter corresponding to one light receiving element is a W filter, and this W filter is arranged. The filter corresponding to the light receiving element horizontally adjacent to the above light receiving element is the G filter selected from among the R filter, G filter, and B filter, and the filters corresponding to the other two light receiving elements are the above-mentioned filters. Cy is two different complementary color filters that transmit the light transmitted by the selected G filter.
It consists of a filter and a Ye filter. Furthermore, in this embodiment, the filters for four adjacent light-receiving elements in any two rows and two columns are arranged periodically with two light-receiving elements in the horizontal direction, but in the vertical direction, every two light-receiving elements are arranged in m columns. Each filter element is replaced in the (m+1) column. In other words, as is clear from the figure, the filters arranged in rows n and (n+1), and the filters arranged in rows (n+2) and (n+3)
Each filter arranged in a row is constructed by interchanging the filters arranged in its column. With this configuration, moiré can be extremely reduced when reading out in interlace.

The present invention is capable of completely interlacing.
This is effective for solid-state imaging devices that have the number of vertical pixels for a frame. For example, the two adjacent
This is particularly effective in solid-state imaging devices in which horizontal lines of rows are simultaneously read out from separate output lines. In the figure, 11 is a horizontal scanning circuit, 12 is a vertical scanning circuit, 13 is an interlace switching circuit, and 14 is a horizontal scanning circuit.
1 is a control signal generation means for interlacing, for example, a flip-flop circuit; 15 is a horizontal readout switch; 16 is an output line common to one horizontal line;
7 is an output line common to other horizontal lines, 18 is a vertical readout switch, and 19 is a light receiving element (photodiode). In this configuration, a control signal is applied to the control terminal 14' for each field, and 2
Select the horizontal lines of the book. This configuration is used because it is advantageous in terms of afterimage and S/N ratio.

Now, using this configuration, the signals on the output lines 16 and 17 are applied to the n and (n+1) terminals of the signal processing circuit shown in FIG. In FIG. 2, the output line 16 always outputs only odd-numbered horizontal lines, and the output line 17 outputs only even-numbered horizontal lines. The signal applied to this terminal is connected to low-pass filters 1 and 1' and bandpass filters 2 and 2', and the outputs of 1 and 1' are added in adder 3 to produce a baseband signal, 2.(R+2G+B) signal. Get to terminal 8. The outputs of the bandpass filters 2 and 2' are added by an adder 4 and detected by a detector 6 to obtain a B signal at an output terminal 9. Further, when the outputs of the bandpass filters 2 and 2' are coupled to the subtracter 5 and then detected by the detector 7, an R signal is obtained at the output terminal 10. Inversion circuit 2
0 and 21, a control signal is applied to the control terminals 22 and 23 to determine whether or not to perform inversion for each horizontal scanning period, or for each field in the case of the configuration shown in FIG. For example, the output of the interlacing switching circuit 13 shown in FIG. 2 may be used as this signal.

FIG. 4 shows the picture elements that become the carrier wave of the B signal and the carrier wave of the R signal when the mosaic color filter of FIG. 1, the solid-state image sensor of FIG. 2, and the signal processing circuit of FIG. 3 are used. is divided into odd fields and even fields. Note that the odd field is n
The (n+1)th row is one set, and the even field is (n
This refers to the case where two horizontal lines, each consisting of lines +1) and (n+2), are read out simultaneously.
Figure a is for a B signal, Figure b is for an R signal,
The solid line is for odd fields, and the dotted line is for even fields.

From the same figure, it is clear that in the embodiment of FIG. 1, when interlacing is performed, moiré is extremely reduced.

According to the present invention described in detail above, it is possible to obtain a solid-state color imaging device with high light utilization efficiency and high resolution.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a configuration example of a solid-state imaging device to which the present invention is applied, FIG. 3 is a diagram showing a configuration example of a signal processing circuit, and FIG. FIG. 2 is a diagram for explaining the effects of the present invention.

Claims (1)

[Claims] 1. A solid-state color imaging device including a plurality of light receiving elements arranged in the horizontal and vertical directions and a mosaic color filter consisting of filter elements arranged corresponding to each of the light receiving elements. In the above, four adjacent filter elements constituting the mosaic color filter are a first filter consisting of an all-color transmission filter and a first filter having different transmission characteristics.
a second filter selected from among a spectral domain transmission filter, a second spectral domain transmission filter, and a third spectral domain transmission filter, which transmits the transmission component of the second filter and has mutually different transmission components; A third consisting of complementary color filters
and a fourth filter, the first filter and the second filter are adjacent to each other in the horizontal direction, and the third filter and the fourth filter are adjacent to each other in the horizontal direction, and the third filter and the fourth filter are adjacent to each other in the horizontal direction. The filter elements are arranged so that the mutual positions of the adjacent first and second filters and the mutual positions of the third and fourth filters are alternated every two light receiving elements in the vertical direction. solid-state color imaging device. 2. The solid-state color imaging device according to claim 1, wherein the second filter is a green transmission filter, and the third and fourth filters are a cyan transmission filter and a yellow transmission filter.