Display system for displaying images acquired by a camera system onto a rearview assembly of a vehicle

A display system for use in a controlled vehicle is provided, and includes a rearview assembly having a display device located behind a mirror element, a camera system configured to acquire images of a scene external of the controlled vehicle, and a processing system configured to receive a signal representative of the acquired images and to produce an image of the scene on the display device of the rearview assembly, wherein the processing system is further configured to adjust the photosensitivity of the camera system based on an input from at least one of an ambient light sensor and a direct glare sensor.

FIELD OF THE INVENTION

The present invention generally relates to display systems and camera systems, and more specifically, to a display system for displaying images acquired by a camera system onto a rearview assembly of a vehicle.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a display system for use in a controlled vehicle is provided. The display system includes a rearview assembly having a display device located behind a mirror element. A camera system is configured to acquire images of a scene external of the controlled vehicle. A processing system is configured to receive a signal representative of the acquired images and to produce images of the scene on the display device of the rearview assembly, wherein the processing system is further configured to adjust the photosensitivity of the camera system based on an input from at least one of an ambient light sensor and a direct glare sensor.

According to another aspect of the present invention, a display system for displaying video images of a scene acquired by a camera system onto a rearview assembly of a vehicle is provided. The display system includes a display device positioned behind a mirror element of the rearview assembly. A processing system is configured to receive signals representative of the acquired video images and to produce images of the scene on the display device of the rearview assembly, wherein the processing system is further configured to adjust the integration time of the camera system based on an input from at least one of an ambient light sensor and a direct glare sensor.

According to another aspect of the present invention, a display system for use in a controlled vehicle is provided. The display system includes a rearview assembly having a display device located behind a mirror element. A camera system is configured to acquire video images of a scene external of the controlled vehicle. A processing system is configured to receive signals representative of the acquired video images and to produce images of the scene on the display device of the rearview assembly, wherein the processing system is further configured to generate a multiplexed signal that is used for adjusting the integration time of the camera system based on an input from at least one sensor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. In the drawings, the depicted structural elements are not to scale and certain components are enlarged relative to the other components for purposes of emphasis and understanding.

The present invention generally relates to a display system for displaying video images of a scene acquired by a camera system onto a rearview assembly of a vehicle.FIG. 1shows an example of a display system10, which includes a rearview assembly12, a camera system14, and a processing system16. In the example shown, signals representative of a scene18imaged by the camera system14are sent to the processing system16, which produces images of the scene18on a display device20of the rearview assembly12. The processing system16also receives input from an ambient light sensor22and a direct glare sensor24to adjust the photosensitivity of the camera system14.

The rearview assembly12is generally shown inFIG. 2and includes a housing26and a mount28for mounting the housing26to the vehicle. The mount28may be of any conventional type such as the type for attaching the rearview assembly12to a windshield, roof, headliner, or overhead console of the vehicle. Rearview assembly12further includes a mirror element30, which may be embodied as an electrochromic element, a prismatic mirror element, or other element used in the automotive industry. The mirror element30may include a partially reflective, partially transmissive coating to hide the display when not in use, as disclosed in U.S. Pat. Nos. 6,356,376 and 6,700,692, the entire disclosures of which are incorporated herein by reference. The display device20of the rearview assembly12may be positioned within the housing26and behind the mirror element30. The display device20may be embodied as a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED) display, or other display suited for use inside a rearview assembly. While the display device20is shown positioned nearest to the driver side of the vehicle, it is to be understood that the display device20may be positioned anywhere behind the mirror element30. In addition, the display device20may be of any shape or size and may constitute all or a portion of the area of the mirror element30. Examples of rearview assemblies having display devices can be found in U.S. Pat. No. 8,339,526 and U.S. Patent Application Publication No. US20090096937 A1, the entire disclosures of which are incorporated herein by reference.

Referring back toFIG. 1, camera system14is operative to view scene18. The camera system14may be any conventional camera system. Examples of suitable camera systems are disclosed in U.S. Patent Application Publication Nos. US 20080192132 A1 and US 20120072080 A1, and in U.S. Provisional Application Nos. 61/500,418 entitled “MEDIAN FILTER” filed on Jun. 23, 2011, by Jon H. Bechtel et al.; 61/544,315 entitled “MEDIAN FILTER” filed on Oct. 7, 2011, by Jon H. Bechtel et al.; and 61/556,864 entitled “HIGH DYNAMIC RANGE CAMERA LOW LIGHT LEVEL FILTERING” filed on Nov. 8, 2011, by Jon H. Bechtel et al., the entire disclosures of which are incorporated herein by reference.

In addition to providing images of scene18for display, the camera system14may also be used for other automotive applications such as exterior light control systems, lane departure warning systems, forward collision warning systems, adaptive cruise control systems, pedestrian detection systems, night vision systems, terrain detection systems, parking assist systems, traffic sign recognition systems, and reverse camera display systems. Examples of systems using camera systems for such purposes are disclosed in U.S. Pat. Nos. 5,837,994, 5,990,469, 6,008,486, 6,049,171, 6,130,421, 6,130,448, 6,166,698, 6,379,013, 6,403,942, 6,587,573, 6,611,610, 6,631,316, 6,774,988, 6,861,809, 7,321,112, 7,417,221, 7,565,006, 7,567,291, 7,653,215, 7,683,326, 7,881,839, 8,045,760, and 8,120,652, and in U.S. Provisional Application Nos. 61/512,213 entitled “RAISED LANE MARKER DETECTION SYSTEM AND METHOD THEREOF” filed on Jul. 27, 2011, by Brock R. Rycenga et al., and 61/512,158 entitled “COLLISION WARNING SYSTEM AND METHOD THEREOF” filed on Jul. 27, 2011, by Brock R. Rycenga et al., which together correspond to United States Patent Application Publication No. US20130028473 A1, the entire disclosures of which are incorporated herein by reference.

As will be obvious to one of ordinary skill in the art, the camera system14may be oriented in a variety of ways to view scenes at various locations about the vehicle. Thus, scene18may include, but is not limited to, the sides, back, front, bottom, top, and inside of the vehicle. Further, the camera system14may be mounted in a variety of locations such as, but not limited to, a tail light(s) or a center high-mounted stop light (CHMSL) assembly, or provided as an integral component such as, but not limited to, behind a rear window as disclosed in U.S. Pat. No. 6,550,949 or inside a rearview assembly as disclosed in U.S. Pat. No. 6,611,610, the entire disclosures of which are incorporated herein by reference.

In the example shown inFIG. 1, the processing system16may be wholly or partially incorporated with the camera system14or the display device20, split amongst the camera system14and the display device20, or provided separate from the camera system14and the display device20. The processing system16is configured to receive at least one NTSC (National Television Standards Committee) analog video signal32from the camera system14and display the content on the display device20of the rearview assembly12. As previously mentioned, the processing system16is also configured to receive input from the ambient light sensor22and the direct glare sensor24to control the photosensitivity of the camera system14. For example, the processing system16may use an ambient light signal34from the ambient light sensor22to determine whether to place the camera system14in a day mode or a night mode setting, wherein the day mode setting includes one or more integration times that enable the camera system14to operate in high ambient light conditions, and the night mode includes one or more integration times that enable the camera system14to operate in low ambient light conditions. As is known to those having ordinary skill in the art, the ambient light sensor22may be positioned in a variety of locations. For example, the ambient light sensor22may be a forward facing light sensor, such as the one described in U.S. Pat. No. 4,917,477, the entire disclosure of which is incorporated herein by reference.

In some instances, video images acquired by the camera system14may become saturated when the camera system14is operating in night mode and is subsequently exposed to light levels in excess of prevailing ambient light conditions. For example, when driving at night, the bright headlights of vehicles approaching from the rear may cause a rearward facing camera system to be exposed to an excess of light and may also cause excessive glare on the rearview assembly12. In this scenario, ambient light levels may not necessarily change, and as such, the processing system16may be unable to remedy the situation by relying solely on the ambient light sensor22. Instead, the processing system16may rely on the direct glare sensor24, which may be placed in the rearview assembly12so as to sense light levels falling on the mirror element30and/or display device20. The direct glare sensor24subsequently sends a direct glare signal36to the processing system16. In response to excessive light levels, the processing system16signals to the camera system14to either adjust the integration time within the night mode setting or switch to a day mode setting altogether if needed to prevent image saturation.

In view of the above, it should be appreciated that the settings derived from the light levels sensed by ambient light sensor22and/or the direct glare sensor24may be used in place of or to supplement any existing photosensitivity settings of the camera system14. Based on the ambient light and direct glare conditions detected by the ambient light and direct glare sensors22and24, respectively, the processing system16sends a control signal38to the camera system14to operate in the appropriate mode. The control signal38may be sent to the camera system14as a separate signal or as a multiplexed signal over existing NTSC signals32between the processing system16and the camera system14.

While the processing system16has been shown herein to receive input from ambient light and direct glare sensors22and24, respectively, it is to be understood that the processing system16may receive input from other devices that are not shown herein such as, but not limited to, rain sensor(s), light sensor(s), automatic vehicle exterior light controller(s), microphone(s), global positioning systems, telecommunication systems, operator interface(s), and a host of other devices, and control the display device20to provide appropriate visual notifications and/or automatically manipulate other devices and systems.

Accordingly, a display system for displaying images acquired by a camera system onto a rearview assembly of a vehicle has been advantageously described herein. The display system10enables the photosensitivity of the camera system14to be adjusted based on inputs from at least one sensor that is presently employed in vehicles.

Although the above embodiments have been described as accounting for variances in scene brightness by adjusting the photosensitivity of the camera system, additional measures may be taken by adjusting the brightness of the display device20as disclosed in U.S. Pat. Nos. 6,550,949 and 7,567,291, and/or by adjusting the reflectivity of the electrochromic mirror element30as disclosed in U.S. Pat. No. 6,700,692, the entire disclosures of which are incorporated herein by reference.