KR20100074367A - Color filter array for image sensor - Google Patents

Abstract

The color filter array of the image sensor according to the embodiment includes a predetermined number of red filters; The same number of green filters as the red filter; Including the same number of blue filters as the red filter; The filters having the same color among the filters are arranged in a Bayer pattern so as not to neighbor each other in the horizontal and vertical directions.

Description

Color Filter Array of Image Sensors {COLOR FILTER ARRAY FOR IMAGE SENSOR}

Embodiments relate to a color filter array of an image sensor.

Complementary Metal Oxide Silicon (CMOS) Image Sensors (CIS) are semiconductor devices that convert an optical image into an electrical signal.

Incident light in the CMOS image sensor is divided into blue, red, and green light through a color filter array. The conventional color filter array for distinguishing incident light is composed of four Bayer patterns, one red filter, one blue filter, and two blue filters. It is composed of an RGGB type including a green filter.

Typically, the red filter and the blue filter are located in the diagonal direction, and the two green filters are located in the remaining diagonal direction. Since the human eye is most sensitive to green, two green filters are arranged. However, the green signal has a specific gravity twice that of blue and red.

In addition, in the conventional color filter array manufacturing method, the red filter has the highest thickness and the blue filter has the lowest thickness by sequentially forming the blue, green, and red filters in order. Accordingly, in the case of blue, since a sufficient amount of light does not reach the light receiver, there is a problem in that the signal is measured lowest.

As described above, the conventional color filter array and the manufacturing method thereof have the highest light sensitivity of green and the lowest blue sensitivity. Due to such a difference in sensitivity, there is a problem in that color reproducibility is not faithful.

The embodiment provides a color filter array of an image sensor that can improve color reproducibility.

The color filter array of the image sensor according to the embodiment includes a predetermined number of red filters; The same number of green filters as the red filter; Including the same number of blue filters as the red filter; The filters having the same color among the filters are arranged in a Bayer pattern so as not to neighbor each other in the horizontal and vertical directions.

According to the embodiment, it is possible to provide a color filter array of an image sensor capable of improving color reproducibility.

Hereinafter, a color filter array of an image sensor according to an exemplary embodiment will be described in detail with reference to the accompanying drawings. However, in describing the embodiments, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In addition, in describing the embodiments, each layer (film), region, pattern, or structure may be “on” or “under” a substrate, each layer (film), region, pad, or pattern. In the case of being described as being formed "in", "on" and "under" include both "directly" or "indirectly" formed through another layer. do. Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

1 is a plan view of a color filter array of an image sensor according to an embodiment. As shown in FIG. 1, the color filter array of the image sensor according to the embodiment is configured by 3 * 3 bayer patterns, and includes three red filters (R) 10. A green filter (G) 20 and three blue filters (B) 30 are included.

Here, each color filter 10, 20, 30 is arranged so that filters of the same color are not adjacent to each other in the horizontal and vertical directions. For example, as shown in Figure 1, when arranged in a 3 * 3 Bayer pattern, each color filter 10, 20, 30 is the same color arranged in a diagonal direction, neighboring in the horizontal and vertical direction It is arranged not to. When the light receiving signal is read from the photodiodes sensing the light received by the color filters 10, 20, and 30, the light receiving signal is read out in the horizontal or vertical direction of the arrayed photodiodes. This is to prevent the color from being concentrated.

As described above, the color filter array according to the embodiment allocates the same number of color filters 10, 20, and 30, and arranges the same color filters evenly in the horizontal and vertical directions so that they do not neighbor each other. The blue light receiving signals may be distributed in the same number.

Meanwhile, when manufacturing the color filter array, the thicknesses of the filters 10, 20, 30 vary according to the generation order of the filters 10, 20, 30, and thus, the respective filters 10, 20, 30 The magnitude of the received light signal varies. In general, the thickness of the last generated filter is larger than the thickness of the previously generated filter, and the larger filter has a larger received signal.

Therefore, in the case of the color filter array according to the embodiment in which the same number of reds, blues, and greens are allocated, it is preferable to generate the green filter 20 that needs the largest signal last. Therefore, the color filter of the present embodiment first generates the blue filter 30 that requires a relatively small signal, and then generates the red filter 10, and lastly generates the green filter 20 that requires the highest amount of light. Create That is, the color filter of the embodiment has the smallest thickness of the blue filter 30 and the largest thickness of the green filter 20.

According to this configuration, the number of the red filter 10, the green filter 20, and the blue filter 30 are equally allocated on the color filter array, but in the case of green where the most signal is needed, a larger amount of blue and red are required. The largest thickness of the green filter 20 is allocated to receive the optical signal.

2 is a state diagram of use of the color filter array of the image sensor according to the embodiment; As shown in FIG. 2, the color filter array of the image sensor according to the embodiment configures a color filter array by arranging N * M 3 * 3 bayer patterns. For example, a color filter array may be configured by arranging 3 * 3 bayer patterns horizontally and vertically, based on 9 * 9 pixels.

When the color filter array is configured based on 9 * 9 pixels, the red filter 10, the blue filter 30, and the green filter 20 are assigned the same number, and the filters of the same color are adjacent in the horizontal and vertical directions. Is arranged not to. Accordingly, the same number of red, blue, and green signals are input to the CDS (Correlation Double Sampler) 100 that reads and processes the received signal in the vertical direction of the pixel, thereby preventing a phenomenon in which a specific color signal is concentrated.

Here, the same number of color signals are input to the CDS 100, but the green signal received through the green filter 20 may have a higher signal intensity than the signals of other colors, thereby improving color reproducibility.

Although described above with reference to the embodiment is only an example and is not intended to limit the invention, those of ordinary skill in the art to which the present invention does not exemplify the above within the scope not departing from the essential characteristics of this embodiment It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

1 is a plan view of a color filter array of an image sensor according to an embodiment;

2 is a state diagram of use of the color filter array of the image sensor according to the embodiment;

Claims (4)

A predetermined number of red filters; The same number of green filters as the red filter; Including the same number of blue filters as the red filter; The filter having the same color of each of the filters are arranged in a Bayer pattern so as not to neighbor each other in the horizontal and vertical directions. The method of claim 1, And a 9 * 9 Bayer pattern in which the red filter, the green filter, and the blue filter are respectively assigned three by three. The method of claim 2, And the red filter, the green filter, and the blue filter are arranged in the same color filter in a diagonal direction. The method of claim 1, And the green filter is formed to have the largest thickness, and the blue filter is formed to have the smallest thickness.

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