JP5900127B2 - Imaging device and image processing system - Google Patents

Description

  The present invention relates to an imaging device and an image processing system.

  Conventionally, a control system (AHB system) that automatically switches between a high beam and a low beam of a vehicle headlight is known. This AHB system includes an imaging device for capturing a color image of a headlight or taillight of a vehicle ahead.

  In this imaging device, pixels that selectively detect R (red) light, pixels that selectively detect G (green) light, and pixels that selectively detect B (blue) light are arranged in a Bayer array. The color of an arbitrary pixel is determined from the detection results of a plurality of pixels adjacent to the pixel. In addition, in the imaging device, a microlens is provided for each pixel in order to increase sensitivity (see Patent Document 1).

JP 2011-176297 A

  The conventional imaging device has a problem that the color of light from a small light source (for example, a taillight of a distant preceding vehicle) cannot be accurately detected (false color is generated). This is because when light from a small light source is incident on only a single pixel, only the color that can be detected by that pixel is detected, and the color of the light cannot be detected by adjacent pixels. For example, when red light from a small light source enters only one pixel that selectively detects G light and does not enter a plurality of adjacent pixels, the color of the light is detected as G. End up.

  The present invention has been made in view of the above points, and an object thereof is to provide an imaging device and an image processing system in which false colors are unlikely to occur.

  The imaging device of the present invention includes an element array including a plurality of types of wavelength selection elements having different wavelengths to be selected, and a microlens that guides incident light to the element array. The microlens includes two or more types including two or more types. It arrange | positions so that the wavelength selection element of this may be straddled.

  According to the imaging device of the present invention, even light from a small light source is incident on two or more wavelength selection elements including two or more types by a microlens. For this reason, since the color of light can be detected not only by a wavelength selection element that directly receives light from a small light source but also by a wavelength selection element adjacent thereto, the color of the light can be detected accurately (false color) Does not occur).

1 is a block diagram illustrating a configuration of an image processing system 101. FIG. 1 is a plan view illustrating a configuration of an imaging device 1. It is sectional drawing in the III-III cross section of FIG. It is sectional drawing in the IV-IV cross section of FIG. It is explanatory drawing showing the method of producing a color using the detection result of the imaging device. It is explanatory drawing showing the effect which the imaging device 1 show | plays. It is explanatory drawing showing a detection result in case there exists the independent microlens 113 for every pixel.

An embodiment of the present invention will be described.
1. Configuration of Image Processing System 101 The configuration of the image processing system 101 will be described with reference to FIG. The image processing system 101 is an in-vehicle system mounted on a vehicle, and includes an optical system 103, the imaging device 1, and an image processing apparatus 105.

  The optical system 103 has a known configuration that forms incident light on the surface of an element array 17 (to be described later) in the imaging device 1. The imaging device 1 has a structure in which a plurality of pixels are arranged, and detects any of R, G, and B components of incident light in each pixel. The detailed structure of the imaging device 1 will be described later.

  Based on the detection result of the imaging device 1, the image processing apparatus 105 creates a color image by a known method such as polarization difference image generation, white balance, color creation (demosaic), noise filter, and the like. By using a known recognition algorithm, the taillight of the preceding vehicle, the headlamp of the oncoming vehicle, the white line of the road ahead, etc. are recognized.

2. Configuration of Imaging Device 1 The configuration of the imaging device 1 will be described with reference to FIGS. The imaging device 1 includes a silicon substrate 3, an R element (a wavelength selection element that selects a red wavelength) 5, a G element (a wavelength selection element that selects a green wavelength) 7, and a B element (selects a blue wavelength) Wavelength selection element 9, polarizing element 11, microlens 13, and lid glass 15.

  The R element 5, G element 7, B element 9, and polarizing element 11 are arranged on the silicon substrate 3 to form an element array 17. In the element array 17, each of the R element 5, the G element 7, the B element 9, and the polarizing element 11 is one pixel. In the element array 17, the R element 5, the G element 7, and the B element 9 form a Bayer array.

  The R element 5, the G element 7, and the B element 9 are elements that convert incident light into electrical signals, such as a CCD and a CMOS, respectively. The R element 5 includes a color filter that selectively transmits light having a red wavelength, and selectively detects light having a red wavelength. The G element 7 includes a color filter that selectively transmits light having a green wavelength, and selectively detects light having a green wavelength. The B element 9 includes a color filter that selectively transmits light having a blue wavelength, and selectively detects light having a blue wavelength. Therefore, the R element 5, the G element 7, and the B element 9 have different wavelengths to be selected.

  The microlens 13 is formed by forming a film of an organic material on the surface of the element array 17. The microlens 13 is formed across six elements. The six elements include an R element 5, a G element 7 (2), a B element 9, and a polarizing element 11 (2). That is, one microlens 13 straddles all kinds of elements of the element array 17. Like the conventional microlens, the microlens 13 guides incident light to the element array 17 and has an effect of increasing the light collection efficiency.

3. Method for Creating Color Using Detection Results of Imaging Device 1 The image processing apparatus 105 uses the well-known demosaicing method for the color in each pixel of the imaging device 1 and includes the pixel and three pixels adjacent thereto. Determined by 4 pixels. For example, in FIG. 5, the color at the pixel of the B element 9 is detected by the blue color detected by the B element 9, the green color detected by the two adjacent G element 7 pixels, and the pixel of the adjacent R element 5. The red color is determined by the demosaic method.

4). Effects produced by the imaging device 1 Effects produced by the imaging device 1 will be described with reference to FIGS. As shown in FIG. 6, light from a small red light source (for example, light from a distant taillight) 301 is incident in the direction of the pixel of the B element 9 and is applied to the adjacent G element 7 and R element 5 pixels. Assume that there is no direct incidence.

  Even in this case, not only the pixel of the B element 9 but also the R element 5 and the G element 7 (two) by the microlens 13 straddling the R element 5, the G element 7 (two), and the B element 9. The light 301 also enters this pixel. Therefore, since the red component and green color of the light 301 can be detected in the pixels of the R element 5 and the G element 7 (two), the color in the pixel of the B element 9 can be accurately detected (false color is generated). Absent).

  On the other hand, unlike the imaging device 1, as shown in FIG. 7, when there is an independent microlens 113 for each pixel, light 301 from a small red light source is incident in the direction of the pixel of the B element 9. Assuming that the light does not enter the adjacent G element 7 and R element 5 pixels, the red component and green color of the light 301 cannot be detected in the R element 5 and G element 7 (two) pixels. The color in the pixel of the B element 9 cannot be accurately detected (false color is generated).

Moreover, the imaging device 1 can detect polarized light in a specific direction by including a polarizing element.
Further, in the imaging device 1, since the microlens 13 straddles all kinds of elements of the element array 17, a false color is hardly generated.

Moreover, in the imaging device 1, since the R element 5, the G element 7, and the B element 9 are arranged in a Bayer array, the color of incident light can be accurately detected.
In addition, this invention is not limited to the said embodiment at all, and it cannot be overemphasized that it can implement with a various aspect in the range which does not deviate from this invention.

  For example, instead of the R element 5, the G element 7, and the B element 9, a wavelength selection element that selects cyan, a wavelength selection element that selects magenta, and a wavelength selection element that selects yellow may be used.

A part (for example, half) of the G element 7 may be a clear wavelength selection element (an element that detects all red, green, and blue).
The element array 17 may not include the polarizing element 11, and the element array 17 may be configured by only the R element 5, the G element 7, and the B element 9. In this case, the microlens 13 extends over four elements (R element 5, G element 7 (two), and B element 9), that is, all kinds of elements included in the element array 17 in this case. can do.

Further, the arrangement of the R element 5, the G element 7, and the B element 9 may be an arrangement other than the Bayer arrangement.
Further, the microlens 13 may cover the entire pixel or a part of the pixel.

  The number of elements that one microlens 13 straddles may be other than 6 (for example, 2, 3, 4, 5). In addition, the type of element in the element that one microlens 13 straddles can be any of 2, 3, and 4.

DESCRIPTION OF SYMBOLS 1 ... Imaging device, 3 ... Silicon substrate, 5 ... R element, 7 ... G element,
9 ... B element, 11 ... polarizing element, 13 ... micro lens,
15 ... lid glass, 17 ... element array, 101 ... image processing system,
103 ... Optical system, 105 ... Image processing device, 113 ... Micro lens,
301 ... light

Claims (5)

An element array (17) including a plurality of types of wavelength selection elements (5, 7, 9) having different wavelengths to be selected;
A microlens (13) for guiding incident light to the element array;
With
The element array further includes a polarizing element (11) arranged on the same plane as the plurality of types of wavelength selection elements,
The image pickup device (1), wherein the microlens is disposed so as to straddle two or more wavelength selection elements including two or more types and the polarization element . Wherein the microlenses 2 or more of the wavelength selection element straddling claim 1 Symbol placing imaging device characterized to include all types of the wavelength selection element. The imaging device according to claim 1 or 2 , wherein the element array includes a wavelength selection element for selecting R, a wavelength selection element for selecting G, and a wavelength selection element for selecting B. In the element array, the wavelength selection element of the plurality of kinds may claim 1-3 imaging device according to any one of which is characterized in that it is arranged by the Bayer array. The imaging device according to any one of claims 1 to 4 ,
An optical system (103) that focuses incident light on the surface of the element array in the imaging device;
An image processing apparatus (105) for creating a color image using the detection result of the imaging device;
An image processing system (101).

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