DE102009036595A1 - Imaging multifunction sensor - Google Patents

Abstract

The invention relates to an image sensor for a driver assistance system. The image sensor is sensitive in the visible and in the infrared wavelength range. By means of filter elements for light in the visible and infrared wavelength range arranged on the image sensor, light of the corresponding wavelength is selected for different pixels or areas of the image sensor.

Description

State of the art

In modern camera sensors for Automotive applications include semiconductor-based image sensors Use that over an active imager area with a plurality of individual photosensitive elements, the so-called Pixels, dispose. According to the available number of pixels and the built-up optics This results in an environment image with a certain resolution and number of individual pixels to be evaluated. Depending on the semiconductor technology used the pixels are sensitive to a certain amount of electromagnetic energy Wavelength range, often in the visible light range up to the near-infrared range of about 950 nm. Newer image sensor solutions based on innovative semiconductor technologies point beyond already a broadband capability up in the far-infrared range of> 1500 nm.

to appropriate preconditioning of the image and targeted evaluation, z. B. simple color detection, the sensitive area of the imager is usually equipped with a filter mask, the so-called color filter array. Usual in the Color filter arrays used, RGB (red green blue) and RGBC (red green blue clear).

Subject of the invention

With the trend of increasing demands on environmental sensors in automobiles have to Performance and functionality of each sensor always be further increased. This invention is the general one Task based, the functionality and the possible Extend the range of functions of imaging sensors.

object The invention is an image sensor for a driver assistance system. The image sensor is sensitive in the visible and in the infrared wavelength range. By means of arranged on the image sensor filter elements for light in the visible and infrared wavelength range is for different pixels or areas of the image sensor selected light of the corresponding wavelength becomes. For example, z. B. one behind an infrared filter element pixels arranged infrared light passing through the infrared filter is transmitted.

Prefers The image sensor includes an active infrared illumination, on whose wavelength the infrared filter elements are tuned.

In a preferred embodiment includes a filter mask as filter elements red, green, blue and infrared. these can especially in a 2 × 2 matrix be arranged (RGB-IR).

Prefers For example, the filter mask includes one or more extended areas with infrared filter elements, in particular horizontal or vertical arranged zones that are over extend one or more pixel row (s) or column (s).

The Infrared filter elements preferably allow light of the wavelength of 800 nm to 1000 nm happen.

Especially The infrared filter elements preferably leave light of wavelength 900 nm or 905 nm.

In In an alternative preferred embodiment, the infrared let Filter elements light of wavelength greater than 1000 nm, ie especially in the far infrared range.

In A preferred embodiment of the invention are over a optical element on two different visibility ranges projected two different areas of the image sensor and the Arrangement of the infrared filter elements corresponds to one of these both areas.

The The invention also includes a lidar sensor having a receiver as a Image sensor according to the invention provides. With it such a lidar sensor in addition to a Camera sensor functionality in the visible wavelength range.

embodiment 1:

One Camera sensor is equipped with an active optical sensor in the near infrared range (Lidar sensor) at z. 800-1000 nm, in particular 900 nm, integrated in one device. To achieve the most cost-efficient and at the same time high-performance overall system, it is advantageous the receiving part of the Lidarsensors also with a suitable image sensor equip. Across from the usual today Solution over discrete Receiving branches with individual diodes is in this way a multi-channel receiving module feasible, which is a high-resolution Illustration about has the field of view.

These Task can according to the invention thereby solved be that on the imager of the camera sensor a suitable color Filter array is applied, which is preferred for certain pixels Selection in the range of the used infrared wavelength, (eg between 800 and 1000 nm, in particular 900 or 905 nm). That's how it turns out z. B. a RGB IR (red green blue InfraRed) Color Filter Array.

Alternatively, this object can be achieved in that the imager of the camera sensor, a suitable color filter Ar ray is applied, which in certain areas of the active pixel area, a preferred selection in the range of infrared wavelength used, for. B. between 800 and 1000 nm, in particular 900 or 905 nm, makes. This can z. Horizontally or vertically arranged zones, each one or many rows or columns of pixels wide.

Of the Advantage of these two, exemplary described reactions, that you get an additional infrared image parallel to the RGB image.

embodiment 2

One Camera sensor without active illumination by an additional Infrared transmitter Using one of the above-described filter arrangement is used for a driver assistance system used. Many modern headlights also have infrared components in the radiated wavelength spectrum, As a result, light-reflecting objects such. B. traffic signs or lane markings safely detected.

Thereby will improve the standard camera features such as traffic sign recognition and track recognition achieved. These can in an embodiment of the invention of the image sensor as described above advantageously taken advantage of become.

Ausführungsbeisiel 3

One another example of the future Functional expansion of camera sensors is the additional Realization of the rain sensor technology already established in the automobile. This functionality can z. B. by means of an additional optical element can be implemented in a camera sensor. To becomes part of the active pixel area for the detection of raindrops used on the windshield. For reliable detection of rain under all lighting situations (eg night) is a suitable active lighting, ideally in invisible to humans Wavelength range necessary.

In order to is another possible Embodiment of the invention, the use of a corresponding Color filter arrays, which in certain areas of the active pixel area a preferred selection in the area for the illumination of the rain sensor used wavelength performs. A possibility Here is the use of infrared lighting, so that said pixel area is matched with the color filter array to the infrared wavelength becomes. This can be also a better decoupling of this function from the other camera functions achieve.

Further inventive reactions are in the application of the above explained, different solutions on a novel broadband image sensor.

there can again by suitable design over the active pixel area of the image sensor Distributes or sectorizes two or more functional areas or areas of use be realized, possible Functions include camera functions, rain sensors, active IR sensors (Near-infrared), passive IR sensors (far-infrared eg for passive Night Vision) u. s. w .. The possible Embodiments are as described above and you get too therefor the different function or usage areas parallel Images for evaluation and so a very cost-effective, multifunctional Overall system.

Claims (9)

Image sensor for a driver assistance system that is sensitive in the visible and in the infrared wavelength range and on the means of visible and infrared filter elements for different Pixels or areas of the image sensor selected light of the corresponding wavelength becomes. Image sensor according to claim 1, comprising an active Infrared illumination, at its wavelength the infrared filter elements are coordinated. An image sensor according to claim 1 or 2, wherein a filter mask as filter elements red, green, includes blue and infrared. Image sensor according to one of the preceding claims, wherein the filter mask one or more extended areas with infrared Includes filter elements. Image sensor according to one of the preceding claims, wherein the infrared filter elements light the wavelength of 800 nm to 1000 nm let pass. Image sensor according to one of the preceding claims, wherein the infrared filter elements pass light of wavelength 900 nm or 905 nm to let. Image sensor according to one of claims 1 to 4, wherein the infrared Filter elements light of wavelength greater than 1000 let it happen. Image sensor according to one of the preceding claims, wherein two different visibility ranges are projected onto two different areas of the image sensor via an optical element and the arrangement of the infrared filter elements corresponds to one of these two areas. Lidarsensor, the receiver as an image sensor after one of the preceding claims provides.