Digital lighting apparatus for vehicle, controller for digital lighting apparatus, and control program for digital lighting apparatus

• US 6,969,183 B2
• Filed: 12/24/2003
• Issued: 11/29/2005
• Est. Priority Date: 12/27/2002
• Status: Expired due to Fees

• Current Assignee: Ichikoh Industries Limited (Valeo SE)
• Original Assignee: Ichikoh Industries Limited (Valeo SE)
• Inventors: Okubo, Yasuhiro, Hayashi, Seiji
• Primary Examiner(s): Sember, Thomas M.
• Assistant Examiner(s): Cranson, Jr., James W
• Application Number:
  US10/744,132
• Publication Number:
  US 20040218401A1
• Time in Patent Office: 706 Days
• Field of Search: 362/466, 362/464, 362/465, 362/283, 362/284, 362/324, 362/276, 359/290, 359/291, 359/292, 359/295, 701/36, 340/825, 315/295
• US Class Current: 362/466
• CPC Class Codes: B60Q 1/085 due to special conditions, e.g. adverse weather, type of road, badly illuminated road signs or potential dangers B60Q1/10, B60Q1/12, B60Q1/1423 take precedence
• CPC Class Codes: B60Q 1/10 due to vehicle inclination, e.g. due to load distribution
• CPC Class Codes: B60Q 1/12 due to steering position
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 1/545 for indicating other traffic conditions, e.g. fog, heavy traffic
• CPC Class Codes: B60Q 2300/054 Variable non-standard intensity, i.e. emission of various beam intensities different from standard intensities, e.g. continuous or stepped transitions of intensity
• CPC Class Codes: B60Q 2300/056 Special anti-blinding beams, e.g. a standard beam is chopped or moved in order not to blind
• CPC Class Codes: B60Q 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/116 Vehicle at a stop
• CPC Class Codes: B60Q 2300/122 Steering angle
• CPC Class Codes: B60Q 2300/124 Steering speed
• CPC Class Codes: B60Q 2300/142 Turn signal actuation
• CPC Class Codes: B60Q 2300/21 Manual control
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/322 Road curvature
• CPC Class Codes: B60Q 2300/324 Road inclination, e.g. uphill or downhill
• CPC Class Codes: B60Q 2300/332 on city roads
• CPC Class Codes: B60Q 2300/333 on suburban or country roads
• CPC Class Codes: B60Q 2300/334 : on motorways
• CPC Class Codes: B60Q 2300/336 : Crossings
• CPC Class Codes: B60Q 2300/41 : preceding vehicle
• CPC Class Codes: B60Q 2300/42 : oncoming vehicle
• CPC Class Codes: B60Q 2300/45 : Special conditions, e.g. pedestrians, road signs or potential dangers
• CPC Class Codes: B60Q 2400/30 : Daytime running lights [DRL], e.g. circuits or arrangements therefor
• CPC Class Codes: B60Q 2400/50 : Projected symbol or information, e.g. onto the road or car body
• CPC Class Codes: B60Q 2900/50 : Arrangements to reconfigure features of lighting or signalling devices, or to choose from a list of pre-defined settings
• CPC Class Codes: F21S 41/62 : for adaptation between right-hand and left-hand traffic
• CPC Class Codes: F21S 41/675 : by moving reflectors

Abstract

A digital lighting apparatus for a vehicle, which employs a reflection digital light deflector, includes a storage unit that stores digital data of a plurality of light distribution patterns and a controller. The controller selects digital data corresponding to a predetermined light distribution pattern from among the digital data stored in the storage unit and controls the reflection digital light deflector, and illuminates a road surface and the like with the predetermined light distribution pattern.

Claims

1. A digital lighting apparatus that illuminates a road surface with a predetermined light distribution pattern, comprising:

an optical engine that includes a light source;

a reflection type digital light deflector that has a plurality of micro mirror elements arranged to be respectively tiltable, that digitally switches a tilt angle of each of the micro mirror elements between a first tilt angle and a second tilt angle to switch a reflection direction of a light from the optical engine between a first reflection direction as an ON state and a second reflection direction as an OFF state;

a light irradiation unit that irradiates an ON state light reflected from the reflection type digital light deflector on a road surface;

a storage unit that stores digital data of a plurality of light distribution patterns; and

a controller that selects a specific digital data corresponding to the predetermined light distribution pattern from among the digital data stored in the storage unit based on an input signal, and that digitally switches a tilt angle of each of the micro mirror elements based on the digital data selected.

2. The digital lighting apparatus according to claim 1, wherein

each of the digital data is created by computer simulation in designing a light distribution of the digital lighting apparatus, including a plurality of binary bits with which a plurality of light intensity gradations are obtained, and

each of the light intensity gradations corresponds to a state of the micro mirror elements, respectively.

3. The digital lighting apparatus according to claim 1, further comprising:

a light distribution pattern selection unit that allows a driver to select a light distribution pattern, and that outputs a selection signal corresponding to the light distribution pattern selected to the controller, wherein

the input signal to the controller is the selection signal from the light distribution pattern selection unit, and

a light distribution pattern irradiated from the light irradiation unit is the light distribution pattern selected by the driver.

4. The digital lighting apparatus according to claim 3, wherein the controller includes

an external signal input unit that inputs an external signal including the selection signal, and that outputs the external signal as a processing signal;

a data selection unit that selects the specific digital data based on the processing signal; and

a control signal output unit that outputs, to the reflection digital light deflector, a control signal for digitally switching the tilt angle of each of the micro mirror elements based on the specific digital data.

5. The digital lighting apparatus according to claim 1, further comprising:

a surrounding environment detector that detects an environment surrounding a vehicle, and that outputs a detection signal, wherein

the input signal to the controller is the detection signal from the surrounding environment detector to determine the environment surrounding the vehicle, and

the light distribution pattern irradiated from the light irradiation unit is an optimum light distribution pattern that is selected by the controller based on the environment surrounding the vehicle determined.

6. The digital lighting apparatus according to claim 5, wherein the surrounding environment detector includes at least one of

a steering sensor that detects one of or both of an angle and a speed of rotating a steering wheel, and that outputs a steering signal;

a raindrop sensor that detects a rain fall, and that outputs a rain signal;

a luminous intensity sensor that detects a brightness of surroundings of the vehicle, and that outputs a luminous intensity signal;

a turn sensor that detects an ON signal of a turn signal switch and that outputs a turn signal;

a vehicle speed sensor that detects a speed of the vehicle, and that outputs a vehicle speed signal;

a wiper sensor that detects an ON signal of a wiper switch and that outputs a wiper signal;

an imaging device that takes an image of information surrounding the vehicle, and that outputs an image signal;

a radar that detects a reflected wave from a target object in surroundings of the vehicle, and that outputs a radar signal;

a humidity sensor that detects a humidity of the surroundings of the vehicle, and that outputs a humidity signal;

a temperature sensor that detects a temperature of the surroundings of the vehicle, and that outputs a temperature signal;

a light sensor that detects an ON signal of a light switch, and that outputs a light signal;

an orientation sensor that detects an orientation of the vehicle, and that outputs an orientation signal;

a global positioning system that outputs a position information signal;

an electronic toll collection unit that outputs a communication signal when the vehicle enters a highway.

7. The digital lighting apparatus according to claim 5, wherein the controller includes

an external signal input unit that inputs an external signal including the selection signal, and that outputs the external signal as a processing signal;

a surrounding environment determination unit that determines the environment surrounding the vehicle based on the processing signal, and that outputs a determination signal;

a data selection unit that selects, based on the determination signal, a digital data corresponding to a light distribution pattern optimum for the environment from among the digital data stored in the storage unit; and

a control signal output unit that outputs, to the reflection digital light deflector, a control signal for digitally switching the tilt angle of each of the micro mirror elements based on the digital data selected by the data selection unit.

8. The digital lighting apparatus according to claim 7, wherein the surrounding environment determination unit includes at least one of:

a vehicle determination unit that determines whether an oncoming vehicle or a preceding vehicle is present based on an image signal and that outputs an oncoming vehicle or preceding vehicle presence signal or an oncoming vehicle or preceding vehicle absence signal;

a road determination unit that determines whether a road is a highway or a general road based on at least one of the image signal, a vehicle speed signal, a position information signal, and a communication signal, and that outputs a highway signal or a general road signal;

an urban district determination unit that determines whether the vehicle is in an urban district based on at least one of the image signal, a luminous intensity signal, and a position information signal, and that outputs an urban signal indicating that the vehicle is in the urban district or a non-urban signal indicating that the vehicle is not in the urban district;

a crossing determination unit that determines whether the vehicle is at a crossing based on at least one of the image signal, a turn signal, and the position information signal, and that outputs a signal indicating that the vehicle is at the crossing or a signal indicating that the vehicle is not at the crossing;

a straight road and curved road determination unit that determines whether a road is straight or curved based on at least one of a steering signal, the vehicle speed signal, and the position information signal, and that outputs a straight signal or a curve signal;

a rain determination unit that determines whether it rains based on a rain signal and a wiper signal, and that outputs a signal indicating that it rains or a signal indicating that it does not rain;

a fog determination unit that determines whether it is foggy based on at least one of the image signal, a radar signal, and a humidity signal and a temperature signal, and that outputs a signal indicating that it is foggy or a signal indicating that it is not foggy;

a snow determination unit that determines whether it snows based on at least one of the image signal, the wiper signal, and the temperature signal, and that outputs a signal indicating that it snows or a signal indicating that it does not snow;

an orientation determination unit that determines whether an orientation of the vehicle changes based on an orientation signal, and that outputs an orientation change signal according to a variation of the orientation of the vehicle; and

a wait-at-stoplight determination unit that determines whether the vehicle is waiting at a stoplight based on one of or all of the vehicle speed signal, the position information signal, and the image signal, and that outputs a signal indicating that the vehicle is waiting at the stoplight the signal or a signal indicating that the vehicle is not waiting at stoplight.

9. The digital lighting apparatus according to claim 8, wherein the surrounding environment determination unit includes a cancellation unit that cancels a determination of one of the oncoming vehicle and preceding vehicle determination unit, the highway and general road determination unit, the urban district determination unit, the crossing determination unit, the straight road and curved road determination unit, the rain determination unit, the fog determination unit, the snow determination unit, the orientation determination unit, and the wait-at-stoplight determination unit.

10. The digital lighting apparatus according to claim 9, wherein the cancellation unit includes a storage unit that stores a content of the cancelled determination of one of the determination units.

11. The digital lighting apparatus according to claim 8, wherein the data selection unit includes

a main data selection unit that selects the digital data on the optimum light distribution pattern for the surrounding environment of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from at least one of the oncoming vehicle and preceding vehicle determination unit, the highway and general road determination unit, the urban district determination unit, the crossing determination unit, the straight road and curved road determination unit, the rain determination unit, the fog determination unit, the snow determination unit, the orientation determination unit, and the wait-at-stoplight determination unit;

and

an interrupt data selection unit that halts and interrupts selection of the main data selection unit and that selects the digital data on the optimum light distribution pattern for one of the vehicle waiting at a stoplight and the orientation of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from one of the wait-at-stoplight determination unit and the orientation determination unit in the surrounding environment determination unit.

12. The digital lighting apparatus according to claim 1, wherein the storage unit is a buffer storage unit that reads the pieces of the digital data on the light distribution patterns stored in a storage medium in groups according to regions and countries through a reader and that stores the read digital data.

13. The digital lighting apparatus according to claim 1, wherein the storage unit stores pieces of dimming control digital data for decreasing or increasing a light intensity of the predetermined light distribution pattern besides the pieces of the digital data on the light distribution patterns, and

the controller selects predetermined dimming control digital data from among the pieces of the dimming control digital data stored in the storage unit based on the input signal, and that digitally, individually controls the switchover of the tilt angle of the each micro mirror element based on the selected, predetermined dimming control digital data.

14. The digital lighting apparatus according to claim 13, further comprising:

a light distribution pattern and dimming control selection unit that allows a driver to select the predetermined light distribution pattern or a predetermined dimming-controlled light, and that outputs a selection signal based on driver'"'"'s selection, wherein

the input signal input to the controller is the selection signal input from the light distribution pattern and dimming control device, and

the light distribution pattern irradiated from the light irradiation unit is the light distribution pattern selected by the driver using the light distribution pattern and dimming control selection unit.

15. The digital lighting apparatus according to claim 13, further comprising:

a surrounding environment detector that detects a surrounding environment of a vehicle and that outputs a detection signal, wherein

the input signal input to the controller is the detection signal input from the surrounding environment detector so that the controller determines the surrounding environment of the vehicle, and

the light distribution pattern irradiated from the light irradiation unit is the light distribution pattern that is selected by the controller by determining the surrounding environment of the vehicle based on the detection signal and that is optimum for the surrounding environment of the vehicle.

16. The digital lighting apparatus according to claim 13, wherein

each piece of the dimming-control data is digital data comprising a plurality of binary bits with which a plurality of light intensity gradations can be obtained, and

dimming control for decreasing or increasing the light-intensity of the predetermined light distribution pattern based on one of the pieces of the dimming-control digital data is binary pulse width modulation and exerted by decreasing or increasing a duty ratio of an ON signal pulse width or a duty ratio of an OFF signal pulse width.

17. The digital lighting apparatus according to claim 13, wherein dimming control for the vehicle waiting at a stoplight is exerted by decreasing the light intensity of the predetermined light distribution pattern to a predetermined light intensity since the vehicle starts waiting at a stoplight until predetermined light intensity decrease time or by increasing the predetermined light intensity to the light intensity of the predetermined light distribution pattern since the vehicle finishes waiting at a stoplight until predetermined light intensity increase time.

18. The digital lighting apparatus according to claim 13, wherein dimming control for daytime and nighttime is exerted by decreasing the light intensity of the predetermined light distribution pattern at the nighttime to a predetermined light intensity, at the daytime or by increasing the light intensity of the predetermined light distribution pattern at the daytime to the predetermined light intensity, at the nighttime.

19. The digital lighting apparatus according to claim 13, wherein dimming control for a general road and a highway and the dimming control for an urban district and suburbs are exerted by increasing the light intensity of the predetermined light distribution pattern for the general road or the urban district to a predetermined light intensity, on the highway or in the suburbs, or by decreasing the light intensity of the predetermined light distribution pattern for the highway or the suburbs to the predetermined light intensity, on the general road or in the urban district.

20. The digital lighting apparatus according to claim 1, wherein

the pieces of the digital data on the light distribution patterns stored in the storage unit are stored in groups according to regions and countries, and

the controller identifies a region and a country where the vehicle is running based on the input signal, accesses the storage unit, obtains the pieces of the digital data on the light distribution patterns for the region and the country where the vehicle is running, selects the digital data on the predetermined light distribution pattern from among the pieces of the digital data on the light distribution patterns obtained based on the input signal, and digitally, individually controls the switch over of the tilt angle of each of the micro mirror elements based on the selected digital data on the predetermined light distribution pattern.

21. The digital lighting apparatus according to claim 20, wherein the input signal for identifying the region and the country where the vehicle is running is a position information signal input from a global positioning system.

22. The digital lighting apparatus according to claim 1, further comprising:

a data change device that can change the pieces of the digital data on the light distribution patterns stored in the storage unit.

23. The digital lighting apparatus according to claim 22, wherein the data change device comprises a storage unit that stores the changed digital data on the light distribution patterns.

24. The digital lighting apparatus according to claim 1, further comprising:

a display unit that displays the selected digital data on the predetermined light distribution pattern to image data and that displays the image data as an image.

25. The digital lighting apparatus according to claim 1, wherein

each of the micro mirror elements of the reflection type digital light deflector is digitally switched over between the first tilt angle and the second tilt angle if the reflection digital light deflector is in a neutral state in which no current is carried, and

the digital lighting apparatus further comprises a low beam irradiation unit that irradiates the reflected light from the reflection digital light deflector in the state in which no current is carried on the road surface in the light distribution pattern for the vehicle passing by the other vehicle.

26. The digital lighting apparatus according to claim 25, further comprising:

a failure detection and display unit that detects the reflected light from the reflection digital light deflector in the state in which no current is carried and that displays that a failure occurs to the digital lighting apparatus.

27. The digital lighting apparatus according to claim 25, wherein

the low beam irradiation unit comprises a shield forms a cut off line in the light distribution pattern for the vehicle passing by the other vehicle,

the digital lighting apparatus further comprises a failure detection and display unit that detects the reflected light from the reflection digital light deflector in the state in which no current is carried and that displays that a failure occurs to the digital lighting apparatus, and

the failure detection and display unit is arranged near the reflection digital light deflector relative to the shield, and comprises an optical sensor that detects a part of a light cut off by the shield in the reflected light from the reflection digital light deflector in the state in which no current is carried.

28. The digital lighting apparatus according to claim 1, further comprising:

an information display unit that allows the controller to control the reflection digital light deflector, that displays information using a contrast between the ON reflected light and an OFF reflected light from the reflection digital light deflector in the predetermined light distribution pattern for illuminating the road surface, through the light irradiation unit.

29. The digital lighting apparatus according to claim 28, further comprising:

an information acquisition device that acquires surrounding information on a vehicle and that outputs the acquired information as an information signal, wherein

the information display unit allows the controller to control the reflection digital light deflector, that displays the information using the contrast between the ON reflected light and the OFF reflected light from the reflection digital light deflector in the predetermined light distribution pattern for illuminating the road surface, through the light irradiation unit, based on the information signal from the information acquisition device.

30. The digital lighting apparatus according to claim 28, wherein the information using the contrast is displayed in the predetermined light distribution pattern for illuminating the road surface and within about 17 meters ahead in a progress direction of a vehicle.

31. The digital lighting apparatus according to claim 28, wherein

the reflection digital light deflector and the light irradiation unit are loaded on each of a left and a right of the vehicle at predetermined intervals,

one of the left and the right reflection digital light deflectors irradiates and displays the information formed by the OFF reflected light in the predetermined light distribution pattern for illuminating the road surface through the light irradiation unit under control of the information display unit, and

the other one of the left and right reflection digital light deflectors irradiates and displays the predetermined light distribution pattern for illuminating the road surface so as to surround a non-lighting portion formed by the OFF reflected light by the information, through the light irradiation unit.

32. The digital lighting apparatus according to claim 28, further comprising:

an imaging device that images the information displayed in the light distribution pattern for the vehicle passing by the other vehicle and that outputs an image signal as an orientation signal, wherein

the controller vertically controls the reflection digital light deflector based on the orientation signal from the imaging device to thereby move a cut line in the light distribution pattern for the vehicle passing by the other vehicle.

33. The digital lighting apparatus according to claim 1, wherein

the pieces of the digital data on the light distribution patterns stored in the storage unit are the digital data on the light distribution pattern for a vehicle passing by the other vehicle and the digital data on the light distribution pattern for the vehicle that is running,

the controller digitally, individually controls the tilt angle of each of the micro mirror elements of the reflection digital light deflector based on the digital data on the light distribution pattern for the vehicle passing by the other vehicle and the digital data on the vehicle that is running stored in the storage unit,

the light distribution patterns for the ON reflected light from the reflection digital light deflector controlled by the controller and irradiated from the light irradiation unit are the light distribution pattern for the vehicle passing by the other vehicle and the light distribution pattern for the vehicle that is running, and

the digital lighting apparatus further comprises an OFF control light irradiation unit that irradiates the OFF reflected light from the reflection digital light deflector controlled by the controller, the OFF reflected light being a beam that does not form the light distribution pattern for the vehicle passing by the other vehicle, on the road surface in the predetermined light distribution pattern in a predetermined direction.

34. The digital lighting apparatus according to claim 33, wherein

the tilt angle of each of the micro mirror elements of the reflection digital light deflector is horizontal, and

the OFF control light irradiation unit irradiates the beam that is the OFF reflected light emitted upward or downward of the low beam that is an ON reflected light emitted from the reflection digital light deflector, on the road surface in the predetermined light distribution pattern in the predetermined direction.

35. The digital lighting apparatus according to claim 33, wherein

the tilt angle of each of the micro mirror elements of the reflection digital light deflector is vertical, and

the OFF control light irradiation unit irradiates the beam that is the OFF reflected light emitted left or right relative to the low beam that is the ON reflected light emitted from the reflection digital light deflector, on the road surface in the predetermined light distribution pattern in the predetermined direction.

36. The digital lighting apparatus according to claim 33, wherein

the tilt angle of each of the micro mirror elements of the reflection digital light deflector is inclined, and

the OFF control light irradiation unit irradiates the beam that is the OFF reflected light emitted aslant relative to the low beam that is the ON reflected light emitted from the reflection digital light deflector, on the road surface in the predetermined light distribution pattern in the predetermined direction.

37. The digital lighting apparatus according to claim 33, wherein the OFF control light irradiation unit irradiates the beam that is the OFF reflected light from the reflection digital light deflector on the road surface in the predetermined light distribution pattern in the predetermined direction as an infrared light.

38. The digital lighting apparatus according to claim 1, wherein

each of the micro mirror elements of the reflection digital light deflector is digitally switched over between the first tilt angle and the second tilt angle if the reflection digital light deflector is in a state in which no current is carried, and wherein

the digital lighting apparatus further comprises:

an optical semiconductor device panel comprising a plurality of optical semiconductor devices that receive the reflected light from the reflection digital light deflector in the state in which no current is carried in a one-by-one correspondence to the micro mirror elements;

a reference data storage unit that is provided in the controller and that stores reference data; and

a comparison and arithmetic device that is provided in the controller, that compares the reference data from the reference data storage unit with measurement data from the optical semiconductor device panel to calculate an error, and that outputs corrected data corrected by as much as the error to the storage unit.

39. A controller of a digital lighting apparatus, for illuminating a road surface in an optimum light distribution pattern for a surrounding environment of a vehicle by the digital lighting apparatus, the digital lighting apparatus comprising:

an optical engine that includes a light source;

a reflection digital light deflector that has a plurality of micro mirror elements respectively arranged to be tiltable, that digitally switches over a tilt angle of each of the micro mirror elements between a first tilt angle and a second tilt angle, and that thereby digitally switches over a reflection direction of a light from the optical engine between an ON or a first reflection direction and an OFF or a second reflection direction;

a storage unit that stores pieces of digital data on a plurality of light distribution patterns;

a surrounding environment detector that detects the surrounding environment of the vehicle and that outputs a detection signal; and

a light irradiation unit that irradiates an ON reflected light emitted from the reflection digital light deflector and having the optimum light distribution pattern for the surrounding environment of the vehicle, on the road surface, the controller comprising;

an external signal input unit that inputs an external signal such as the selection signal from the surrounding environment detector and that outputs the input external signal as a processing signal;

a surrounding environment determination unit that determines the surrounding environment of the vehicle based on the processing signal from the external signal input unit and that outputs a determination signal;

a data selection unit that selects the digital data on the optimum light distribution pattern for the surrounding environment of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from the surrounding environment determination unit; and

a control signal output unit that outputs a control signal for digitally, individually controlling the switchover of the tilt angle of each of the micro mirror element based on the digital data on the light distribution pattern optimum for the surrounding environment of the vehicle and selected by the data selection unit, to the reflection digital light deflector.

40. The controller of the digital lighting apparatus according to claim 39, wherein each of the pieces of the digital data on the light distribution patterns is created by computer simulation in designing a light distribution of the digital lighting apparatus, digital data comprising a plurality of binary bits with which a plurality of light intensity gradations can be obtained, and digital data allocated one of the light intensity gradation corresponding to one of the micro mirror elements.

41. The controller of the digital lighting apparatus according to claim 39, wherein the surrounding environment determination unit includes at least one of

an oncoming vehicle and preceding vehicle determination unit that determines whether an oncoming vehicle or a preceding vehicle is present based on an image signal obtained by imaging surrounding information on the vehicle by an imaging device of the surrounding environment detector and output from the imaging device, and that outputs an oncoming vehicle or preceding vehicle presence signal or an oncoming vehicle or preceding vehicle absence signal;

a highway and general road determination unit that determines whether a road is a highway or a general road based on at least one of the image signal, a vehicle speed signal obtained by detecting a vehicle speed by a vehicle speed sensor in the surrounding environment detector and output from the vehicle speed sensor, a position information signal output from a global positioning system in the surrounding environment detector, and a communication signal output from an electronic toll collection in the surrounding environment detector, and that outputs a highway signal or a general road signal;

an urban district determination unit that determines whether the vehicle is in an urban district based on at least one of the image signal, a luminous intensity signal obtained by detecting a brightness of surroundings of the vehicle by a luminous intensity sensor in the surrounding environment detector and output from the luminous intensity sensor, and the position information signal, and that outputs a signal indicating that the vehicle is in the urban district or a signal indicating that the vehicle is not in the urban district;

a crossing determination unit that determines whether the vehicle is at a crossing based on at least one of the image signal, a turn signal obtained by detecting an ON signal of a turn signal switch by a turn sensor in the surrounding environment detector and output from the turn sensor, and the position information signal, and that outputs a signal indicating that the vehicle is at the crossing or a signal indicating that the vehicle is not at the crossing;

a straight road and curved road determination unit that determines whether a road is straight or curved based on at least one of a steering signal obtained by detecting one of or both of a steering angle and a steering speed of a steering wheel by a steering sensor in the surrounding environment detector and output from the steering sensor and the vehicle speed signal, and the position information signal, and that outputs a straight signal or a curve signal;

a rain determination unit that determines whether it rains based on a rain signal obtained by detecting that it rains by a rain sensor in the surrounding environment detector and output from the rain sensor and a wiper signal obtained by detecting an ON signal of a wiper switch by a wiper sensor in the surrounding environment detector and output from the wiper sensor, and that outputs a signal indicating that it rains or a signal indicating that it does not rain;

a fog determination unit that determines whether it is foggy based on at least one of the image signal, a radar signal obtained by detecting a reflected wave from a target object in the surroundings of the vehicle by a radar in the surrounding environment detector and output from the radar, and a humidity signal obtained by detecting a humidity of the surroundings of the vehicle by a humidity sensor in the surrounding environment detector and output from the humidity sensor and a temperature signal obtained by detecting a temperature of the surroundings of the vehicle by a temperature sensor in the surrounding environment detector and output from the temperature sensor, and that outputs a signal indicating that it is foggy or a signal indicating that it is not foggy;

a snow determination unit that determines whether it snows based on at least one of the image signal, the wiper signal, and the temperature signal, and that outputs a signal indicating that it snows or a signal indicating that it does not snow;

an orientation determination unit that determines whether an orientation of the vehicle changes based on an orientation signal obtained by detecting an orientation of the vehicle by an orientation sensor in the surrounding environment detector ad output from the orientation sensor, and that outputs an orientation change signal according to a variation of the orientation of the vehicle; and

a wait-at-stoplight determination unit that determines whether the vehicle is waiting at a stoplight based on one of or all of the vehicle speed signal, the position information signal, and the image signal, and that outputs a signal indicating that the vehicle is waiting at a stoplight or a signal indicating that the vehicle is not waiting at a stoplight.

42. The controller of the digital lighting apparatus according to claim 41, wherein the data selection unit includes

a main data selection unit that selects the digital data on the optimum light distribution pattern for the surrounding environment of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from at least one of the oncoming vehicle and preceding vehicle determination unit, the highway and general road determination unit, the urban district determination unit, the crossing determination unit, the straight road and curved road determination unit, the rain determination unit, the fog determination unit, the snow determination unit, the orientation determination unit, and the wait-at-stoplight determination unit;

and

an interrupt data selection unit that halts and interrupts selection of the main data selection unit and that selects the digital data on the optimum light distribution pattern for one of the vehicle waiting at a stoplight and the orientation of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from one of the wait-at-stoplight determination unit and the orientation determination unit in the surrounding environment determination unit.

43. A control program of a digital lighting apparatus for illuminating a road surface in an optimum light distribution pattern for a surrounding environment of a vehicle by the digital lighting apparatus, the digital lighting apparatus comprising:

an optical engine that includes a light source;

a reflection digital light deflector that has a plurality of micro mirror elements respectively arranged to be tiltable, that digitally switches over a tilt angle of each of the micro mirror elements between a first tilt angle and a second tilt angle, and that thereby digitally switches over a reflection direction of a light from the optical engine between an ON or a first reflection direction and an OFF or a second reflection direction;

a light irradiation unit that irradiates an ON reflected light emitted from the reflection digital light deflector and having the optimum light distribution pattern for the surrounding environment of the vehicle, on the road surface;

a surrounding environment detector that detects the surrounding environment of the vehicle and that outputs a detection signal; and

a storage unit that stores pieces of digital data on a plurality of light distribution patterns, wherein

in order to illuminate the road surface in the optimum light distribution pattern for the surrounding environment of the vehicle, the control program makes a computer to execute;

allowing an external signal input unit to input an external signal such as the selection signal from the surrounding environment detector, and to output the input external signal as a processing signal;

allowing a surrounding environment determination unit to determine the surrounding environment of the vehicle based on the processing signal from the external signal input unit, and to output a determination signal;

allowing a data selection unit to select the digital data on the optimum light distribution pattern for the surrounding environment of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from the surrounding environment determination unit; and

allowing a control signal output unit to output a control signal for digitally, individually controlling switchover of the tilt angle of each of the micro mirror element based on the digital data on the light distribution pattern that is optimum for the surrounding environment of the vehicle and that is selected by the data selection unit, to the reflection digital light deflector.

44. The control program of the digital lighting apparatus according to claim 43, wherein each of the pieces of the digital data on the light distribution patterns is created by computer simulation in designing a light distribution of the digital lighting apparatus, digital data comprising a plurality of binary bits with which a plurality of light intensity gradations can be obtained, and digital data allocated one of the light intensity gradation corresponding to one of the micro mirror elements.

45. The control program of the digital lighting apparatus according to claim 43, wherein the surrounding environment determination unit executes at least one of:

allowing an oncoming vehicle and preceding vehicle determination unit to determine whether an oncoming vehicle or a preceding vehicle is present based on an image signal obtained by imaging surrounding information on the vehicle by an imaging device of the surrounding environment detector and output from the imaging device, and to output an oncoming vehicle or preceding vehicle presence signal or an oncoming vehicle or preceding vehicle absence signal;

allowing a highway and general road determination unit to determine whether a road is a highway or a general road based on at least one of the image signal, a vehicle speed signal obtained by detecting a vehicle speed by a vehicle speed sensor in the surrounding environment detector and output from the vehicle speed sensor, a position information signal output from a global positioning system in the surrounding environment detector, and a communication signal output from an electronic toll collection in the surrounding environment detector, and to output a highway signal or a general road signal;

allowing an urban district determination unit to determine whether the vehicle is in an urban district based on at least one of the image signal, a luminous intensity signal obtained by detecting a brightness of surroundings of the vehicle by a luminous intensity sensor in the surrounding environment detector and output from the luminous intensity sensor, and the position information signal, and to output a signal indicating that the vehicle is in the urban district or a signal indicating that the vehicle is not in the urban district;

allowing a crossing determination unit to determine whether the vehicle is at a crossing based on at least one of the image signal, a turn signal obtained by detecting an ON signal of a turn signal switch by a turn sensor in the surrounding environment detector and output from the turn sensor, and the position information signal, and to output a signal indicating that the vehicle is at the crossing or a signal indicating that the vehicle is not at the crossing;

allowing a straight road and curved road determination unit to determine whether a road is straight or curved based on at least one of a steering signal obtained by detecting one of or both of a steering angle and a steering speed of a steering wheel by a steering sensor in the surrounding environment detector and output from the steering sensor and the vehicle speed signal, and the position information signal, and to output a straight signal or a curve signal;

allowing a rain determination unit to determine whether it rains based on a rain signal obtained by detecting that it rains by a rain sensor in the surrounding environment detector and output from the rain sensor and a wiper signal obtained by detecting an ON signal of a wiper switch by a wiper sensor in the surrounding environment detector and output from the wiper sensor, and that outputs a signal indicating that it rains or a signal indicating that it does not rain;

a fog determination unit that determines whether it is foggy based on at least one of the image signal, a radar signal obtained by detecting a reflected wave from a target object in the surroundings of the vehicle by a radar in the surrounding environment detector and output from the radar, and a humidity signal obtained by detecting a humidity of the surroundings of the vehicle by a humidity sensor in the surrounding environment detector and output from the humidity sensor and a temperature signal obtained by detecting a temperature of the surroundings of the vehicle by a temperature sensor in the surrounding environment detector and output from the temperature sensor, and to output a signal indicating that it is foggy or a signal indicating that it is not foggy;

allowing a snow determination unit to determine whether it snows based on at least one of the image signal, the wiper signal, and the temperature signal, and to output a signal indicating that it snows or a signal indicating that it does not snow;

allowing an orientation determination unit to determine whether an orientation of the vehicle changes based on an orientation signal obtained by detecting an orientation of the vehicle by an orientation sensor in the surrounding environment detector ad output from the orientation sensor, and to output an orientation change signal according to a variation of the orientation of the vehicle; and

allowing a wait-at-stoplight determination unit to determine whether the vehicle is waiting at a stoplight based on one of or all of the vehicle speed signal, the position information signal, and the image signal, and to output a signal indicating that the vehicle is waiting at a stoplight or a signal indicating that the vehicle is not waiting at a stoplight.

46. The control program of the digital lighting apparatus according to claim 45, wherein the data selection unit executes

a main data selection step of allowing a main data selection unit to select the digital data on the optimum light distribution pattern for the surrounding environment of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from at least one of the oncoming vehicle and preceding vehicle determination unit, the highway and general road determination unit, the urban district determination unit, the crossing determination unit, the straight road and curved road determination unit, the rain determination unit, the fog determination unit, the snow determination unit, the orientation determination unit, and the wait-at-stoplight determination unit;

and

an interrupt data selection step of allowing an interrupt data selection unit to halt and interrupt selection of the main data selection unit and to select the digital data on the optimum light distribution pattern for one of the vehicle waiting at a stoplight and the orientation of the vehicle from among the pieces of the digital data on the light distribution patterns stored in the storage unit based on the determination signal from one of the wait-at-stoplight determination unit and the orientation determination unit in the surrounding environment determination unit.