JP2008213595A - Headlight control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a headlight control device for controlling an irradiating light of the headlight for shaking up a driver by the light of the headlight necessarily provided in a vehicle. <P>SOLUTION: The headlight control device 1 has a type which introduces the light from a lamp 3 to a projection part 4 having the same constitution as the projection part in a liquid crystal projector, and generates a projection image by the projection part 4 to project to the front of the vehicle. An ECU2 is equipped with an image signal acquisition means 21 for detecting the image signal from an on-vehicle camera 5, an image processing means 22 for detecting the position of driver's eyeball and eyelid by processing the image signal, an awaking degree determination means 23 for determining whether or not the driver is in an awaking degree decreased state, and a projection image control means 24 for generating an awaken image on the projection part 4 based on the determination of the driver in lowering state in the awaking degree. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a headlight control device provided in a vehicle headlight device using a projector.

  A projector type device is known as a headlight control device. For example, the apparatus described in Patent Document 1 is this. In the apparatus described in Patent Document 1, a transmissive liquid crystal projector is used, and light from a light source is passed through a liquid crystal panel on which an optical image is written, and projected to the front of the vehicle through a lens.

  Patent Document 1 describes that the emission direction and emission range of a high beam, a low beam, and the like can be controlled by forming a predetermined optical image on a liquid crystal panel. Further, it is described that the color of the irradiation light can be adjusted. In addition, information on the current position of the car and information on the direction of travel created by the car navigation system is displayed on the road, and when the driver gives a left turn instruction to the car, an arrow indicating the direction of travel is displayed. It also describes displaying on the road.

For example, as described in Patent Document 2, various methods for determining the driver's arousal level are known. Furthermore, it is also known that a light source unit emits light to awaken an occupant other than the driver at the timing of reaching the destination (Patent Document 3).
JP 2004-136838 A JP-A-8-332871 JP 2006-27534 A

  As described above, Patent Literature 1 describes that the light distribution can be variously changed by using the headlamp control device as a projector. However, what kind of light distribution control is executed at what timing is not described.

  On the other hand, as described in Patent Document 2, various methods for determining the driver's arousal level are known. When the arousal level is reduced, the technique described in Patent Document 3 is used. By irradiating the driver with light, it becomes possible to wake up the driver whose arousal level has decreased. However, in this case, since a light source unit that irradiates light toward the driver is required, extra cost is required.

  Therefore, the present invention is to provide a headlamp control apparatus that controls the irradiation light of the headlamp in order to wake up the driver by the light of the headlamp that is always provided in the vehicle.

  In order to achieve the object, the invention described in claim 1 is for a vehicle having a light source and a projection unit that receives light from the light source, generates a projection image from the incident light, and projects the projected image forward of the vehicle. A headlight control device provided in the headlight device, wherein the driver is in a state of reduced wakefulness set in advance, wakefulness determining means, and the wakefulness reduced by the wakefulness determining means Projection image control means for causing the projection unit to generate an awakening image for awakening the driver based on the determination of the state.

  In this way, when it is determined that the driver is in a state of reduced arousal level, an awakening image is generated by the projection unit. The awakening image generated by the projection unit is projected forward of the vehicle. Accordingly, an awakening image is displayed in front of the driver in a state where the arousal level is lowered. When the driver sees the awakening image, it can be expected that the driver's awakening level returns to a normal state. In addition, since the driver can recognize that the degree of arousal is decreasing, the driver is encouraged to take a break.

  The invention described in claim 2 is characterized in that, in claim 1, the awakening image includes a figure.

  Usually, since the light emitted from the headlamp does not include a figure, if the figure is included in the awakening image in this way, the awakening image is particularly conscious of the driver (that is, in a state where the degree of arousal is high). Can be seen. Therefore, the effect of returning the awakening level to a normal state and the effect of prompting a break can be particularly expected.

  Here, the graphic included in the awakening image may be a pattern such as a striped pattern according to claim 3 or may be a character or a symbol. When it is a character or a symbol, it is preferable that it promotes a break as in claim 4. In this way, the effect of prompting the driver to take a break is particularly increased.

  Further, as described in claim 5, it is preferable that the position of the figure in the projection image changes with time. In this way, since the position of the figure projected in front of the driver changes with time, the driver's consciousness can be further attracted by the awakening image. Therefore, the effect of returning the awakening level to a normal state and the effect of promoting a break can be further expected.

  A sixth aspect of the present invention is the first aspect of the present invention, wherein the awakening image is an image in which a bright part range is composed of a single awakening color, and the awakening color is determined to be the state of reduced arousal level. The color is different from the previous one.

  If it does in this way, if it determines with a state of arousal level fall, the vehicle front will be illuminated by the awakening color different from it. Even in this case, it can be expected that the driver's arousal level returns to a normal state due to a change in the color of the light illuminating the front, and the driver is encouraged to take a break.

  The awakening color only needs to be different from at least one of brightness, hue, and saturation, which are the three elements of color. It is preferable that the colors have different brightness and the brightness changes with time. If it does in this way, the brightness of the light projected ahead of vehicles will change with time. Therefore, the effect of returning the awakening level to a normal state and the effect of promoting a break can be further expected.

  In addition, when changing the brightness over time, the headlamp may be temporarily turned off. However, as in claim 8, the lower limit of the change range of the brightness of the awakening color can confirm the front of the vehicle It is preferable that the brightness is high. In this way, it is possible to obtain an effect of returning the awakening level to a normal state and an effect of prompting a break while ensuring a certain degree of visibility in front of the vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a vehicle headlamp apparatus 1 including a headlamp control ECU (hereinafter simply referred to as an ECU) 2 corresponding to a headlamp control apparatus to which the present invention is applied.

  As shown in FIG. 1, the vehicle headlamp apparatus 1 includes a lamp 3 that is a light source, a projection unit 4, an ECU 2, and an in-vehicle camera 5. Although only one lamp 3 and one projection unit 4 are shown in FIG. 1, the vehicle headlamp device 1 actually includes a pair of left and right lamps 3 and a projection unit 4. The pair of lamps 3 and projection unit 4 are arranged at the front end of the vehicle.

  As the lamp 3, various known lamps used as vehicle head lamps such as a halogen lamp and a xenon lamp can be used. The lamp 3 is controlled to be turned on / off by the ECU 2.

  The projection unit 4 has the same configuration as the projection unit in a known transmissive liquid crystal projector. That is, the projection unit 4 includes a first dichroic mirror 41, a second dichroic mirror 42, a first mirror 43, a second mirror 44, a third mirror 45, a red liquid crystal panel 46R, a green liquid crystal panel 46G, and a blue liquid crystal panel. 46B, a prism 47, and a projection lens 48 are provided.

  The first dichroic mirror 41 is a mirror that reflects green and blue light and transmits red light. On the other hand, the second dichroic mirror 42 is a mirror that reflects green light and transmits red and blue light. The second dichroic mirror 42 is disposed so as to face the reflection surface of the first dichroic mirror 41, and light from which green and blue light are mixed is incident from the first dichroic mirror 41. The second dichroic mirror 42 transmits blue light and reflects green light in the direction in which the prism 47 is disposed.

  The first mirror 43 totally reflects the light transmitted through the first dichroic mirror 41 (that is, red light) in the direction in which the prism 47 is disposed. The second mirror 44 totally reflects the light transmitted through the second dichroic mirror 42 (that is, blue light) in the direction in which the third mirror 45 is disposed. The third mirror 45 totally reflects the light from the second mirror 44 in the direction in which the prism 47 is disposed.

  The red liquid crystal panel 46R generates various images (optical images) by being controlled by the ECU 2. The red liquid crystal panel 46R is disposed between the first mirror 43 and the prism 47, and the red light from the first mirror 43 passes through the red liquid crystal panel 46R, so that the red image is converted into the prism 47. Is incident on.

  The green liquid crystal panel 46G also generates various images by being controlled by the ECU 2. The green liquid crystal panel 46G is disposed between the second dichroic mirror 42 and the prism 47, and green light from the second dichroic mirror 42 passes through the green liquid crystal panel 46G, so that a green image is formed. The light enters the prism 47.

  The blue liquid crystal panel 46B is also controlled by the ECU 2 to generate various images. The blue liquid crystal panel 46B is disposed between the third mirror 45 and the prism 47, and blue light from the third mirror 45 passes through the blue liquid crystal panel 46B, so that a blue image is converted into the prism 47. Is incident on.

  The prism 47 generates one projection image by combining the red, blue, and green images respectively incident from the three liquid crystal panels 46R, 46G, and 46B, and the projection lens 48 is disposed on the projection image. Output in the direction of Here, when the image generated in each liquid crystal panel 46 is an image without any figure, a white image having an outline determined by the frame of the liquid crystal panel 46 is generated as a projection image.

  The projection lens 48 expands the light from the prism 47 and irradiates it forward of the vehicle. As a result, the projected image synthesized by the prism 47 is enlarged and projected forward of the vehicle. Projection is performed so that the range of the projected image projected forward of the vehicle includes all of the irradiation range of the conventional headlamp when the beam is a high beam and the irradiation range of the conventional headlamp when the beam is a low beam. The size and shape of the lens 48 for use are determined.

  The ECU 2 is a computer that includes a CPU, a ROM, a RAM, and the like. The ECU 2 executes the program stored in advance in the ROM while the CPU uses the temporary storage function of the RAM, whereby the image signal acquisition unit 21, the image processing unit 22, the arousal level determination unit 23, and the projection image control unit 24. Function as.

  The image signal acquisition unit 21 acquires an image signal from the in-vehicle camera 5 at a predetermined cycle in a state where the projection image is projected from the projection unit 4 to the front of the vehicle. This in-vehicle camera 5 includes a lens and a CCD as an image sensor. The installation position of the in-vehicle camera 5 is an instrument panel 6 of the car as shown in FIG. 2, and the imaging range is set so that the face of the driver 7 can be imaged.

  The image processing unit 22 continuously extracts small regions including the eyes of the driver in the image by analyzing the image signal acquired by the image signal acquisition unit 21. Then, the positions of the eyeball and eyelid are detected by processing the extracted region by a known method such as binary image processing or edge image processing.

  The arousal level determination means 23 detects blinking and eyeball position change from the eyelid position and eyeball position detected by the image processing means 22, and whether or not the driver is in a state of reduced arousal level based on the blinking and eyeball position change. Determine whether. Specifically, it is known that when the degree of arousal decreases, the eye closure time for blinking increases, and the rapid eye movement component decreases, so the eye closure time for blinking is calculated and the rapid eye movement component Calculate the quantity. Then, the driver is awakened by comparing these calculated values with preset reference values, or by comparing the amount or rate of change of these calculated values with the passage of time with preset reference values. It is determined whether or not the degree is reduced.

  In this embodiment, the driver's arousal level is determined in this way, but the arousal level may be determined using only one of the blinking eye closing time and the rapid eye movement component, The driver's arousal level may be determined by an image analysis method. Furthermore, the arousal level may be determined by a method other than image analysis, such as a method using a pulse wave (described later).

  The projection image control unit 24 sequentially determines the projection images to be generated in the projection unit 4, and controls the three liquid crystal panels 46R, 46G, and 46B so that the determined projection images are generated. When the driver determines that the driver is in a state of reduced wakefulness by the wakefulness determination means 23, a wakeup image prepared in advance for the purpose of making the driver wake up is determined as a projected image. On the other hand, when it is not determined that the degree of arousal is reduced, a projection image different from the awakening image is determined. The projection image different from the awakening image is, for example, an image in which the bright part range is set so that the light distribution range of the light irradiated to the front of the vehicle becomes a normal low beam or high beam light distribution range, The bright part range is a low beam projection image or a high beam projection image composed of a single color used for normal high beams and low beams. The bright area refers to a range of a projected image formed when light from a light source passes through any one of the liquid crystal panels 46R, 46G, and 46B.

  On the other hand, for example, as shown in FIG. 3, the awakening image is an image in which the entire bright area is a striped pattern parallel to the vehicle width direction and spaced at regular intervals. Before the low arousal state is determined, the low-beam projection image or the high-beam projection image described above is generated as a projection image, and if the monochromatic light is irradiated in front of the vehicle, the driver has a low arousal level. By determining the state, the light irradiated to the front of the vehicle changes from monochromatic light to striped light. This change in light can be expected to return the driver's arousal level to a normal state. In addition, since the driver can recognize that the degree of arousal is decreasing, the driver is encouraged to take a break.

  Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram showing a schematic configuration of the vehicle headlamp device 10 of the second embodiment. The ECU 2 of the second embodiment functions as a pulse wave signal acquisition unit 25, a waveform processing unit 26, a wakefulness determination unit 27, and a projection image control unit 24. The vehicle control apparatus 10 of the second embodiment includes a pulse wave sensor 11 instead of the in-vehicle camera 5. Other configurations are the same as those of the first embodiment.

  The pulse wave sensor 11 sequentially detects a pulse wave from the driver, and detects a pulse wave at a predetermined part of the driver. The predetermined part is, for example, a heart, and a cardiac potential signal can be detected as a pulse wave in the heart by bringing a plurality of electrodes into contact with the driver. In this case, a plurality of electrodes may be arranged on the steering wheel. Moreover, you may detect pulse waves, such as a wrist, an arm, a chest, and a neck. In that case, the pulse wave sensor is directly attached to the detection site.

  The pulse wave signal acquisition unit 25 continuously acquires pulse wave signals from the pulse wave sensor 11 in a state where the projection image is projected from the projection unit 4 in front of the vehicle. The waveform processing means 26 determines the detection time of a predetermined part of the pulse wave by processing the pulse wave indicated by the pulse wave signal using a known waveform processing algorithm. The predetermined portion is, for example, a rising point or a peak of a pulse wave, and when the pulse wave is a cardiac potential signal, for example, it is an R wave.

  The arousal level determination means 27 determines the pulse cycle by calculating the time interval of the detection time of the predetermined part of the pulse wave determined by the waveform processing means 26, and the driver is in a state of reduced arousal level based on the pulse cycle. It is determined whether or not. Specifically, when the arousal level decreases, the pulse period becomes longer (the pulse rate decreases). Therefore, by comparing the pulse period with a preset reference value, or when the time period of the pulse period has elapsed. It is determined whether or not the driver is in a state of reduced arousal level by comparing the accompanying change amount or change rate with a preset reference value. Further, a technique for determining the arousal level of a living body based on fluctuations in the pulse cycle is also known, and this known technique may be used to determine whether or not the arousal level is reduced.

  The projection image control means 24 is the same as that of the first embodiment. When the driver is determined to be in a state of reduced wakefulness by the wakefulness determination means 23, an awakening image prepared in advance for the purpose of awakening the driver is used. Determine the projected image. On the other hand, when it is not determined that the degree of arousal is reduced, a projection image different from the awakening image is determined. Then, the three liquid crystal panels 46R, 46G, and 46B are controlled so that the determined projection image is generated.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, It can implement in various changes within the range which does not deviate from the summary.

  For example, in the above-described embodiment, the awakening image is an image in which the entire bright area is a striped pattern, but the awakening image may be an image including characters that prompt a break (for example, “requiring a break”). In this case, the effect of prompting the driver to take a break is particularly great. Moreover, you may include the character other than the character which promotes a break, and figures other than a character in an awakening image. When the figure is included in the awakening image as such, the position of the figure may be changed over time. If the position of the figure is changed over time, the driver will see the awakening image more consciously. Therefore, the effect of returning the awakening level to a normal state and the effect of prompting a break can be particularly expected.

  Moreover, you may comprise the bright part range of an awakening image by a single awakening color. The awakening color is set to, for example, red, but may be a color different from that before being determined to be a state of reduced arousal level. Note that a color different from that before the determination means that at least one of brightness, hue, and saturation is different. Further, the brightness of the awakening color may be changed over time. In this case, if the lower limit of the brightness change range is set to a brightness at which the front of the vehicle can be confirmed, the effect of returning the wakefulness to a normal state while securing the visibility in front of the vehicle to some extent, and the effect of promoting a break Is obtained.

  In the above-described embodiment, the projection unit 4 has the same configuration as that of the transmissive liquid crystal projector. However, the projection unit 4 may be a projector of another type (for example, a single-plate DLP (Digital Light Processing: registered trademark)). The projector may have the same configuration as the projection unit in a projector, a CRT projector, or the like).

It is a figure which shows schematic structure of the vehicle headlamp apparatus 1 containing headlamp control ECU2 to which this invention was applied. It is a figure explaining the installation position of the vehicle-mounted camera. It is a figure which shows an example of the awakening image projected ahead of a vehicle. It is a figure which shows schematic structure of the vehicle headlamp apparatus 10 of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Vehicle headlamp apparatus, 2: Headlamp control ECU (headlamp control apparatus), 23: Awakening degree determination means, 24: Projection image control means, 27: Awakening degree determination means, 3: Lamp (light source) ), 4: projection unit, 5: on-vehicle camera, 10: headlamp control ECU (vehicle headlamp device), 11: pulse wave sensor

Claims (8)

A headlamp control device provided in a vehicle headlamp device that includes a light source and a projection unit that receives light from the light source, generates a projection image from the incident light, and projects the projected image forward of the vehicle. ,
Wakefulness determination means for determining whether or not the driver is in a preset state of reduced wakefulness;
A projection image control means for causing the projection unit to generate a wake-up image for waking up the driver based on the wake-up degree determined by the wake-up degree determination means. Light control device.   The headlamp control device according to claim 1, wherein the awakening image includes a figure.   The headlamp control device according to claim 2, wherein the figure is a striped pattern.   3. The headlamp device according to claim 2, wherein the graphic is a character or a symbol that prompts a break.   The headlamp control device according to any one of claims 2 to 4, wherein the position of the figure in the projection image changes with time.   2. The awakening image according to claim 1, wherein the awakening image is an image in which a bright portion range is configured with a single awakening color, and the awakening color is different from that before it is determined as the state of reduced arousal level. A headlight control device characterized by.   7. The headlamp control device according to claim 6, wherein the awakening color is a color having a brightness different from that of the previous color, and the brightness changes with time.   8. The headlamp control device according to claim 7, wherein a lower limit of a change range of the brightness of the awakening color is set to a brightness at which the front of the vehicle can be confirmed.

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