Vehicular vision system

• US 20030122930A1
• Filed: 12/20/2002
• Published: 07/03/2003
• Est. Priority Date: 05/22/1996
• Status: Active Grant

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Schofield, Kenneth, Vadas, Keith J., Larson, Mark L.
• Granted Patent: US 6,891,563 B2
• Time in Patent Office: Days
• US Class Current: 348/148
• CPC Class Codes: B60R 1/23 with a predetermined field of view
• CPC Class Codes: B60R 1/30 providing vision in the non-visible spectrum, e.g. night or infrared vision
• CPC Class Codes: B60R 2300/103 using camera systems provided with artificial illumination device, e.g. IR light source
• CPC Class Codes: B60R 2300/105 using multiple cameras
• CPC Class Codes: B60R 2300/106 using night vision cameras
• CPC Class Codes: B60R 2300/107 using stereoscopic cameras
• CPC Class Codes: B60R 2300/205 using a head-up display
• CPC Class Codes: B60R 2300/207 using multi-purpose displays, e.g. camera image and navigation or video on same display
• CPC Class Codes: B60R 2300/303 using joined images, e.g. multiple camera images
• CPC Class Codes: B60R 2300/305 merging camera image with lines or icons
• CPC Class Codes: B60R 2300/802 for monitoring and displaying vehicle exterior blind spot views
• CPC Class Codes: B60R 2300/804 for lane monitoring
• CPC Class Codes: B60R 2300/8053 for bad weather conditions or night vision
• CPC Class Codes: B60R 2300/806 for aiding parking
• CPC Class Codes: B60R 2300/8066 for monitoring rearward traffic
• CPC Class Codes: B60R 2300/8086 for vehicle path indication
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A rearview vision system for a vehicle includes at least one image capture device directed rearwardly with respect to the direction of travel of the vehicle. A display system displays an image synthesized from output of the image capture device. The display system is preferably contiguous with the forward field of view of the vehicle driver at a focal length that is forward of the vehicle passenger compartment. A plurality of image capture devices may be provided and the display system displays a unitary image synthesized from outputs of the image capture devices which approximates a rearward-facing view from a single location, such as forward of the vehicle.

Claims

1. A rearview vision system for a vehicle, comprising:

at least two image capture devices positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of said vehicle; and

a display system which displays an image synthesized from outputs of said image capture devices and which approximates a rearward-facing view from a single location.

2. The rearview vision system in claim 1 wherein said single location is forward of the driver with respect to said direction of travel and said rearward-facing view is unobstructed by the vehicle.

3. The rearview vision system in claim 1 wherein said image capture devices are spatially separated.

4. The rearview vision system in claim 1 wherein the displayed image includes a dead space which would be occupied by said vehicle in said view.

5. The rearview vision system in claim 4 wherein said dead space is the size of a footprint of said vehicle in said view.

6. The rearview vision system in claim 4 wherein said dead space includes perspective lines which are aligned with said direction of travel.

7. The rearview vision system of claim 1 wherein said at least two image capture devices comprises at least three image capture devices.

8. The rearview vision system in claim 7 wherein said at least three image capture devices include at least two side image capture devices positioned on opposite lateral sides of said vehicle and at least one center image capture device laterally between said side image capture devices.

9. The rearview vision system in claim 7 wherein said at least three image capture devices are at substantially the same height.

10. The rearview vision system in claim 7 wherein said at least three image capture devices are aimed along non-parallel axes.

11. The rearview vision system in claim 8 wherein the displayed image includes an image portion from each of said image capture devices and wherein said image portion from said center image capture device has a vertically central portion and vertically upper and lower portions, wherein said upper and lower portions are laterally wider than the said central portion.

12. The rearview vision system in claim 8 wherein the displayed image includes an image portion from each of said image capture devices and wherein said image portion from said center image capture device is compressed.

13. The rearview vision system in claim 8 wherein the displayed image includes an image portion from each of said image capture devices and wherein each of said image portions has a horizontal field of view that is less than 70 degrees.

14. The rearview vision system in claim 13 wherein said horizontal field of view of said center image portion from said center capture device is less than approximately 12 degrees.

15. The rearview vision system in claim 14 wherein said horizontal field of view of said image portion from said center image capture device is between approximately 3 degrees and approximately 8 degrees.

16. The rearview vision system in claim 1 wherein said display system includes multiple contiguous display surfaces, one of said surfaces for each of said images.

17. The rearview vision system in claim 1 wherein said display system includes a display surface for displaying all of said images.

18. The rearview vision system in claim 1 wherein each of said image capture devices is a CMOS imaging array.

19. The rearview vision system in claim 8 wherein the displayed image includes an image portion from said center image capture device which has a horizontal width that is narrower than the horizontal width of image portions from said side image capture devices.

20. The rearview vision system in claim 19 wherein said horizontal width of said image portion from said center image capture device is dynamically adjustable.

21. The rearview vision system in claim 20 wherein said horizontal width of said image portion from said center image capture device is adjustable in response to vehicle speed.

22. A rearview vision system for a vehicle, comprising:

at least three image capture devices mounted to the vehicle and directed generally rearwardly with respect to the direction of travel of said vehicle, at least two of said image capture devices being side image capture devices respectively mounted on opposite lateral sides of said vehicle and at least one of said image capture devices being a center image capture device mounted between said side image capture devices; and

a display system which displays an image synthesized from outputs of said image capture devices, the displayed image including an image portion from each of said image capture devices;

wherein the image portion from said center image capture devices is compressed.

23. The rearview vision system in claim 22 wherein said image portion from said center image capture device is vertically compressed.

24. The rearview vision system in claim 23 wherein said image portion from said center image capture device is compressed by deleting particular ones of said lines.

25. The rearview vision system in claim 24 wherein a greater number of lines are removed further away from a vertical center of said image portion from said center image capture device.

26. The rearview vision system in claim 24 including adjusting values of adjacent pixels as a function of pixel values of removed lines.

27. The rearview vision system in claim 22 wherein said image portion from said center image capture device has a vertically central portion and vertically upper and lower portions, wherein said upper and lower portions are laterally wider than said central portion.

28. The rearview vision system in claim 22 including a dead space vertically below said image portion from said center image capture device.

29. The rearview vision system in claim 28 wherein said dead space is the size of a footprint of said vehicle in said view.

30. The rearview vision system in claim 28 wherein said dead space includes perspective lines which are aligned with said direction of travel.

31. The rearview vision system in claim 22 wherein said display system includes multiple contiguous display surfaces, one of said surfaces for each of said image portions.

32. The rearview vision system in claim 22 wherein said display system includes a display surface for displaying all of said image portions.

33. The rearview vision system in claim 22 wherein each of said image capture devices is a CMOS imaging array.

34. The rearview vision system in claim 22 wherein said at least three image capture devices are at substantially the same height on the vehicle.

35. The rearview vision system in claim 22 wherein said at least three image capture devices are aimed along non-parallel axes.

36. A rearview vision system for a vehicle having a gear actuator, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of said vehicle;

a display system which displays an image synthesized from output of said at least one image capture device; and

image enhancement means for enhancing the displayed image including a graphic overlay superimposed on said image.

37. The rearview vision system in claim 36 wherein said graphic overlay includes indicia of the anticipated path of travel of the vehicle.

38. The rearview vision system in claim 37 wherein said graphic overlay is disabled when the vehicle'"'"'s gear actuator is not in reverse gear.

39. The rearview vision system in claim 37 wherein said indicia has a form that responds to the rate of turn of the vehicle.

40. The rearview vision system in claim 39 wherein said indicia form responds to at least one of the vehicle'"'"'s steering system, the vehicle'"'"'s differential system, and a compass.

41. The rearview vision system in claim 36 wherein said graphic overlay has a form that is a function of at least one of the direction or travel and speed of the vehicle.

42. The rearview vision system in claim 36 wherein said graphic overlay is a distance indicia indicating distances behind the vehicle of objects juxtaposed within the grid.

43. The rearview vision system in claim 42 wherein said indicia has a form that responds to the rate of turn of the vehicle.

44. The rearview vision system in claim 43 wherein said indicia form responds to at least one of the vehicle'"'"'s steering system, the vehicle'"'"'s differential system, and a compass.

45. The rearview vision system in claim 36 wherein said at least one image capture device includes a plurality of image capture devices and wherein the displayed image is synthesized from outputs of said image capture devices and approximates a rearward-facing view from a single location.

46. The rearview vision system in claim 45 wherein said single location is forward of the driver with respect to said direction of travel.

47. The rearview vision system in claim 36 wherein the displayed image includes a dead space which would be occupied by said vehicle in said view.

48. The rearview vision system in claim 47 wherein said dead space is the size of a footprint of said vehicle in said view.

49. The rearview vision system in claim 47 wherein said dead space includes perspective lines which are aligned with said direction of travel.

50. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle; and

a display system displaying a rear image synthesized from output of said at least one image capture device substantially contiguous with the forward field of view of the vehicle driver at a focal length that is forward of the vehicle passenger compartment.

51. The rearview vision system in claim 50 wherein said display system displays an image at a focal length that is within the depth of field of a vehicle driver viewing a distant object.

52. The rearview vision system in claim 50 wherein said display system displays an image either generally above or generally below the central forward field of view of the vehicle driver.

53. The rearview vision system in claim 50 wherein said display system includes an opaque viewing portion which blocks view of near field objects located between the forward field of view of the vehicle driver and the displayed image.

54. The rearview vision system in claim 50 wherein said display system defines an observation cone within which an image displayed by the display system can be observed and further including accommodating means for accommodating variation in relationship between a driver'"'"'s head and said observation cone.

55. The rearview vision system in claim 54 wherein said accommodating means includes adjustment means for adjusting said observation cone in at least one of a horizontal and a vertical direction.

56. The rearview vision system in claim 54 wherein said accommodating means includes establishing the rearward field of view captured by said capture device and displayed on said display system beyond that normally observed by a driver.

57. The rearview vision system in claim 50 wherein said display system defines an observation cone within which an image displayed by the display system can be observed, wherein said observation cone is adjustable in at least one of a horizontal and a vertical direction.

58. The rearview vision system in claim 57 including an adjustment mechanism which adjusts said observation cone in said at least one of a horizontal and a vertical direction.

59. The rearview vision system in claim 58 wherein said adjustment mechanism includes an electrically operated actuator which is controllable by a driver-operable switch.

60. The rearview vision system in claim 50 wherein said display system has a variable luminance output which is varied as a function of ambient light levels.

61. The rearview vision system in claim 60 wherein the luminance output of said display system is responsive to one of a vehicle headlight activation control, an ambient light sensor, and an indication of ambient light level developed by said at least one image capture device.

62. The rearview vision system in claim 60 wherein said display system includes a user comfort level setting to establish a desired luminance output level at a particular ambient light level.

63. The rearview vision system in claim 50 wherein said display system includes an image generator and an image magnifier which magnifies an image generated by said image generator.

64. The rearview vision system in claim 50 wherein said display device is an opaque display.

65. The rearview vision system in claim 64 wherein said opaque display is in-line with the generally forward field of view of the vehicle driver.

66. The rearview vision system in claim 64 wherein said opaque display is at an angle with the generally forward field of view of the driver and directed toward the vehicle driver'"'"'s generally forward field of view by a reflection device.

67. The rearview vision system in claim 50 wherein said display device is a view-through heads-up display which projects an image on an image combiner which combines the projected image with an image forward of the vehicle.

68. The rearview vision system in claim 67 wherein said image combiner includes a surface of a vehicle windshield.

69. The rearview vision system in claim 67 wherein said display device combines an image of a polygon with the rear image in order to border the rear image and differentiate the rear image from an image forward of the vehicle.

70. The rearview vision system in claim 50 wherein said at least one image capture device includes at least two image capture devices and wherein said display system displays an image synthesized from outputs of said at least two image capture devices which approximates a rearward-facing view from a single location.

71. The rearview vision system in claim 70 wherein the rear image displayed by said display system has an aspect ratio that is between approximately 4:

1 and approximately 2;

1.

72. The rearview vision system in claim 71 wherein the rear image displayed by said display system has an aspect ratio that is approximately 8:

3.

73. The rearview vision system in claim 72 wherein said display system also displays a supplemental image.

74. The rearview vision system in claim 73 wherein said display system is reconfigurable in order to selectively display different supplemental images.

75. The rearview vision system in claim 73 wherein said supplemental image includes at least one of pager information, telephone number listing, global positioning system output, map, route guidance information, intelligent vehicle highway system information, vehicle radio control settings, vehicle environmental system settings, vehicle speed, vehicle heading, and turn signal indicators.

76. The rearview vision system in claim 50 wherein said display system also displays a supplemental image.

77. The rearview vision system in claim 76 wherein said display system is reconfigurable in order to selectively display different supplemental images.

78. The rearview vision system in claim 76 wherein said supplemental image includes at least one of pager information, telephone number listing, global positioning system output, map, route guidance information, intelligent vehicle highway system information, vehicle radio control settings, vehicle environmental system settings, vehicle speed, vehicle heading, and turn signal indicators.

79. The rearview vision system in claim 50 wherein the rear image displayed by said display system has an aspect ratio that is between approximately 4:

1 and 2;

1.

80. The rearview vision system in claim 79 wherein the rear image displayed by said display system has an aspect ratio that is approximately 8:

3.

81. The rearview vision system in claim 53 wherein said housing includes a bezel around at least a portion of the displayed image, wherein said bezel has a narrow portion adjacent the forward field of view of the vehicle driver.

82. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle; and

a display system displaying a rear image captured by said at least one image capture device, wherein said rear image displayed by said display system is a unitary image having an aspect ratio that is between approximately 4;

1 and approximately 2;

1.

83. The rearview vision system in claim 82 wherein the rear image displayed by said display system has an aspect ratio that is approximately 8:

3.

84. The rearview vision system in claim 82 wherein said display system also displays a supplemental image.

85. The rearview vision system in claim 84 wherein display system is reconfigurable in order to selectively display different supplemental images.

86. The rearview vision system in claim 84 wherein said supplemental image includes at least one of pager information, telephone number listing, global positioning system output, map, route guidance information, intelligent vehicle highway system information, vehicle radio control settings, vehicle environmental system settings, vehicle speed, vehicle heading, and turn signal indicators.

87. The rearview vision system in claim 82 wherein said at least one image capture device includes a plurality of image capture devices and wherein the rear image is synthesized from a plurality of images captured by said plurality of image capture devices which approximates a rearward-facing view from a single location.

92. The rearview vision system in claim 83 wherein said display system is an opaque display.

93. The rearview vision system in claim 92 wherein said opaque display is in-line with the generally forward field of view of the vehicle driver.

94. The rearview vision system in claim 92 wherein said opaque display is at an angle with the generally forward field of view of the driver and directed toward the vehicle driver'"'"'s generally forward field of view by a reflection device.

95. The rearview vision system in claim 92 wherein said display displays said rear image substantially contiguous with the forward field of view of the vehicle driver.

96. The rearview vision system in claim 95 wherein said display displays said rear image laterally substantially directly forward of the vehicle driver.

97. The rearview vision system in claim 95 wherein said display displays said rear image positioned either above or below the central forward field of view of the vehicle driver.

98. The rearview vision system in claim 92 wherein a portion of said display blocks the view of near field objects between the vehicle driver'"'"'s forward field of view and said display.

88. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of said vehicle; and

a display system which displays an image synthesized from output of said at least one image capture device as a unitary image;

wherein said display system includes at least one image generator associated with said at least one image capture device and an optical correction system which amplifies image generated by said image generator to increase the focal lengths of the image generated by the image generator.

89. The rear vision system in claim 88 wherein said display device is a view-through heads-up display which projects an image on an image combiner which combines the projected image with an image forward of the vehicle.

90. The rearview vision system in claim 89 wherein said image combiner includes a surface of a vehicle windshield.

91. The rearview vision system in claim 89 wherein said display device combines an image of a polygon with the rear image in order to border the rear image and differentiate the rear image from an image forward of the vehicle.

99. The rearview vision system in claim 88 wherein said display system defines an observation cone within which an image displayed by the display system can be observed and further including accommodating means for accommodating variation in relationship between a driver'"'"'s head and said observation cone.

100. The rearview vision system in claim 99 wherein said accommodating means includes adjustment means for adjusting said observation cone in at least one of a horizontal and a vertical direction.

101. The rearview vision system in claim 99 wherein said accommodating means includes said image generator establishing the rearward field of view captured by said capture device and displayed on said display system beyond that normally observed by a driver.

102. The rearview vision system in claim-88 wherein said display system defines an observation cone within which an image displayed by the display system can be observed, wherein said observation cone is adjustable in at least one of a horizontal and a vertical direction.

103. The rearview vision system in claim 102 including an adjustment mechanism which adjusts said observation cone in said at least one of a horizontal and a vertical direction.

104. The rearview vision system in claim 103 wherein said adjustment mechanism includes an electrically operated actuator which is controllable by a driver-operable switch.

105. The rearview vision system in claim 88 wherein said display system has a variable luminance output which is varied as a function of ambient light levels.

106. The rearview vision system in claim 105 wherein the luminance output of said display system is responsive to one of a vehicle headlight activation control, an ambient light sensor, and an indication of ambient light level developed by said at least one image capture device.

107. The rearview vision system in claim 105 wherein said display system includes a user comfort level to establish a desired luminance output level at a particular ambient light level.

108. The rearview vision system in claim 88 including a plurality of image capture devices and a plurality of image generators, each associated with one or more of said image capture devices and wherein said optical correction system merges images captured by said image capture device.

109. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device; and

an electrically operated optical device which is responsive to a drive signal in order to have a partial light transmission level;

wherein said drive signal is produced from said output of said at least one image capture device.

110. The rearview vision system in claim 109 wherein said electrically operated optical device is at least one of an electro-optic rearview mirror, an electro-optic window and a prismatic rearview mirror.

111. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device; and

a near infrared illumination device positioned to illuminate an area outside of the vehicle in order to enhance an image captured by said at least one image capture device.

112. The rearview vision system in claim 111 wherein said illumination device produces substantially greater infrared light output than visible light output.

113. The rearview vision system in claim 112 wherein said illumination device is actuated in response to the vehicle being placed in reverse gear.

114. The rearview vision system in claim 112 wherein said illumination device floods areas around a trailer of a truck.

115. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device;

a housing for said image capture device; and

an antenna positioned in said housing in order to receive electromagnetic radiation of a particular characteristic.

116. The rearview vision system in claim 115 wherein said antenna is one of a global positioning system antenna, a cellular telephone antenna, a radar antenna, and a garage door opener antenna.

117. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device; and

designation means for measuring the distance of objects from the vehicle and indicating objects which have a predetermined positional relationship to the vehicle.

118. The rearview vision system in claim 117 wherein said designation means includes a distance measuring device.

119. The rearview vision system in claim 117 wherein said distance measuring device is one of a passive infrared sensor, a radar sensor, an active infrared sensor and an ultrasonic sensor.

120. The rearview vision system in claim 119 wherein said distance measuring device has a sensing field of view that is substantially coincident with the field of view of said image capture device.

121. The rearview vision system in claim 117 wherein said designation means produces an indication on said rear image of objects which have a predetermined positional relationship to the vehicle.

122. A rearview vision system for a vehicle, comprising:

at least two image capture devices closely positioned on the vehicle with at least partially overlapping fields of view and directed generally rearwardly with respect to the direction of travel of the vehicle; and

a stereoscopic display system displaying a stereoscopic rear image synthesized from outputs of said at least two image capture devices.

123. The rearview vision system for a vehicle wherein said at least two image capture devices includes multiple pairs of image capture devices with at least partially overlapping fields of view in each pair and wherein said display system displays a rear image synthesized from outputs of said multiple pairs of image capture devices which approximates a rearward-facing view from a single location.

124. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device; and

means responsive to said output for detecting road lane markings rearward of the vehicle.

125. The rearview vision system in claim 124 wherein said display system displays a position of the vehicle with respect to the detected road lane markings.

126. The rearview vision system in claim 124 including a driver alertness warning which is responsive to the position of the vehicle with respect to the detected road lane markings.

127. The rearview vision system in claim 124 including an infrared light source for illuminating a portion of a road rearward of the vehicle.

128. The rearview vision system in claim 124 including a forward-facing road lane marking detector.

129. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device; and

an infrared communication channel defined from said output which receives communications external of the vehicle.

130. The rearview vision system in claim 129 wherein said infrared communication channel is responsive to at least one of a temporal and a spatial pattern of an infrared signal.

131. The rearview vision system in claim 130 wherein said infrared communication channel determines at least one of relative speed and distance between the source of an infrared signal and the vehicle.

132. The rearview vision system in claim 129 wherein said infrared communication channel is responsive to infrared signals received from one of a stationary source and a source on another vehicle.

133. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device; and

an interface between said output and said display device which synchronously maps image pixels from said output to said display system.

134. The rearview vision system in claim 133 wherein said interface transmits pixel data which represents changes in the captured image.

135. The rearview vision system in claim 134 wherein said pixel data which represents changes in the captured image includes image data and pixel position data.

136. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle; and

a display system displaying a rear image synthesized from output of said at least one image capture device;

wherein said at least one image capture device includes an extended dynamic range to respond to variations in image illumination.

137. The rearview vision system in claim 136 wherein said image capture device is capable of operating in one of a color mode and a monochrome mode and wherein said extended dynamic range is achieved by changing between said modes in response to image illumination conditions.

138. The rearview vision system in claim 136 wherein said image capture device captures an image during an exposure interval and wherein said extended dynamic range is achieved by combining exposure intervals of different lengths.

139. The rearview vision system in claim 136 wherein said image capture device includes an infrared shutter which is selectively operable to generally pass infrared radiation during low image illumination conditions and block infrared radiation during high image illumination conditions.

140. The rearview vision system in claim 139 wherein said infrared shutter is one of an electrochromic shutter and a liquid crystal shutter.

141. The rearview vision system in claim 136 including a plurality of image capture devices and including image intensity coordination between said image capture devices.

142. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle;

a display system displaying a rear image synthesized from output of said at least one image capture device;

a heater in at least one of said image capture device and said display system; and

a control which energizes said heater during low temperature conditions prior to starting the vehicle.

143. The rearview vision system in claim 142 wherein said control includes at least one of a proximity sensor to sense a user approaching the vehicle and a remote keyless entry sensor responsive to a remote keyless entry signal.

144. The rearview vision system in claim 142 including a heater in both said image capture device and said display system.

145. A rearview vision system for a vehicle, comprising:

at least one image capture device positioned on the vehicle and directed generally rearwardly with respect to the direction of travel of the vehicle; and

a display system displaying a rear image synthesized from output of said at least one image capture device;

wherein said rear image has a pixel resolution in the range of between approximately 2 arc-minutes and approximately 8 arc-minutes.

146. The rearview vision system in claim 145 wherein said resolution is approximately 6 arc-minutes.

147. The rearview vision system in claim 145 including a plurality of image capture devices and wherein said resolution is divided between said image capture devices.