JP2017013515A - Light projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light projection device for lightening a wide range in a uniform state, at low cost.SOLUTION: A light projection device 10 uses a protection plate 11 for protecting a display surface of a meter display 4 which is installed in a vehicle 1, as a light guide plate. A light emission control part 13 controls light emission of an IR light source part 12, guides the IR light from the IR light source part 12 with the protection plate 11 for radiating the light into inside of the vehicle 1. Therefore, inside of the vehicle 1 can be lightened over a wide range in a uniform state, in the light projection device 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a projector that irradiates infrared light as illumination for a camera that captures an occupant in a passenger compartment.

  2. Description of the Related Art In recent years, a system has been proposed that detects unsafe behavior such as a driver's drowsiness and looking aside in a moving body such as an automobile and performs braking such as warning or automatic braking. In this system, in order to acquire a driver's image without being affected by external disturbances such as sunlight, a method of irradiating the driver with near infrared light (IR light) and imaging with a near infrared camera Is generally used (see, for example, Patent Document 1).

JP 2012-168748 A

It is desirable that the near infrared light illuminates the driver in a wide range and uniformly. However, the installation space for the light source in the passenger compartment is limited, and it is difficult to ensure the installation location.
Therefore, for example, in Patent Document 1, a near-infrared light source is embedded in a backlight of a liquid crystal display device that displays a pointer indicating a measured value such as a vehicle speed and an engine speed as a meter image, and the near-infrared from the backlight is displayed. It has been proposed to emit light through a special color filter that diffuses light with a light guide plate and allows near-infrared light to pass through. In the case of this configuration, there is a problem that the price is high because a special color filter is used.

  The present invention has been made to solve the above-described problems, and an object thereof is to realize a light projecting device that illuminates a wide range and uniformly at a low cost.

  A light projecting device according to the present invention includes a protective plate that protects a display surface of a display device installed in a vehicle interior, a light source unit that makes infrared light incident on the protective plate, and controls light emission of the light source unit. And a light emission control unit for guiding the infrared light from the protective plate to irradiate the vehicle interior.

  According to the present invention, since the protective plate of the display device is used as an infrared light guide plate, it is possible to realize a light projector that illuminates the vehicle interior in a wide range and uniformly. Further, since the protective plate of the display device is used as an infrared light guide plate, a space for newly installing the light guide plate is not required.

It is a figure which shows the outline | summary of the driver sensing system using the light projection apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structural example of the driver sensing system using the light projection apparatus which concerns on Embodiment 1. FIG. 3 is a block diagram illustrating a configuration example of a protection plate of the light projecting device according to Embodiment 1. FIG. 1 is a cross-sectional view illustrating an outline of a light projecting device according to a first embodiment. It is a front view which shows an example of the meter display incorporating the light projection apparatus which concerns on Embodiment 1. FIG. 2 is a diagram illustrating an example of a hardware configuration of a light projecting device according to Embodiment 1. FIG. 6 is a flowchart illustrating an operation example of the driver sensing system using the light projecting device according to the first embodiment. It is a block diagram which shows the structural example of the protection board of the light projector which concerns on Embodiment 2 of this invention. It is a figure which shows the example which formed the 2nd IR light irradiation part in the protective plate of the light projector which concerns on Embodiment 2. FIG. It is a front view which shows an example of the meter display incorporating the light projector which concerns on Embodiment 2. FIG. It is a figure explaining the cornea reflection method in Embodiment 2, and is the figure which looked at the driver | operator's eyeball from the top. It is a figure explaining the cornea reflection method in Embodiment 2, and is the figure which looked at the driver | operator's eyeball from the front. 10 is a flowchart illustrating an operation example performed by the light projecting device according to Embodiment 2 in step ST7 illustrated in FIG.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an outline of a driver sensing system using a light projecting device 10 according to Embodiment 1 of the present invention. FIG. 2 is a block diagram illustrating a configuration example of the driver sensing system.
The driver sensing system includes a light projecting device 10 that irradiates IR light toward the driver 2 from the dashboard 3 side in front of the driver's seat in the vehicle interior 1, an IR camera 5 that captures IR light reflected by the driver 2, and And an image processing device 6 that processes the image captured by the IR camera 5 to recognize the face direction or blink of the driver 2 and estimates the state of the driver 2 such as looking aside or falling asleep.

  The light projecting device 10 according to the first embodiment uses a protective plate 11 that protects the display surface of the meter display 4 installed on the dashboard 3 in front of the driver 2 as a light guide plate for the IR light source unit 12. . The meter display 4 is a liquid crystal display device that displays a pointer or the like for instructing measurement values such as a vehicle speed and an engine speed as a meter image. An IR light source unit 12 is installed on the edge of the protective plate 11 of the meter display 4, and the IR light emitted from the IR light source unit 12 is scattered by the protective plate 11 to irradiate the driver 2 in a wide range and uniformly. In FIG. 1, IR light from the IR light source unit 12 is indicated by a solid line arrow.

  Since the existing protective plate 11 is used as the light guide plate, it is not necessary to secure a space for installing the IR light source unit 12 and the light guide plate. Moreover, since uniform light is irradiated from the protective plate 11, it is gentle to the driver's 2 eyes. Furthermore, since it is not necessary to add an IR light source and a color filter to the meter display 4 as in the prior art, it is only necessary to devise the protective plate 11, so that the development cost is low. In addition, the processing when the driver sensing system is retrofitted in the vehicle interior 1 is easy and inexpensive.

Hereinafter, a specific example of a driver sensing system using the light projecting device 10 according to the first embodiment will be described.
As shown in FIG. 2, the light projecting device 10 includes a protection plate 11, an IR light source unit 12, and a light emission control unit 13.
The protection plate 11 is a resin or glass plate that protects the display surface of the meter display 4.
The light emission control unit 13 outputs to the IR light source unit 12 a light emission control signal for switching on and off the light emission of the IR light source unit 12 and controlling the intensity of the IR light.
The IR light source unit 12 emits IR light based on the light emission control signal from the light emission control unit 13. The IR light source unit 12 may be installed on an edge in any direction of the protection plate 11 in the vertical and horizontal directions. The IR light source unit 12 may be any light source that emits IR light, such as an LED that emits IR light, an EL (Electroluminescence), or a halogen lamp.

The IR camera 5 is an imaging device that is installed in front of the driver 2 and images the face or upper body of the driver 2. The IR camera 5 transmits the captured image of the driver 2 to the image processing device 6. The IR camera 5 may be installed at the lower center or upper part of the meter display 4, or may be installed near the center console or the rearview mirror.
The IR camera 5 includes a lens 51, an IR transmission filter 52, and an image sensor 53.

The lens 51 may have a field angle of about 50 to 90 degrees that captures only the driver 2, or a wide-angle lens (for example, 100 degrees or more) that can capture not only the driver 2 but also a passenger sitting in the passenger seat or the rear seat. ) May be used.
The IR transmission filter 52 is a band-pass filter that cuts the visible light wavelength in order to reduce disturbances such as sunlight and transmits only the wavelength of the IR light emitted from the light projecting device 10. The IR transmission filter 52 may be a lens type or a film type. Further, the lens 51, the IR transmission filter 52, and the image sensor 53 may be arranged in this order, or the IR transmission filter 52, the lens 51, and the image sensor 53 may be arranged in this order.
The imaging element 53 is an element that converts incident light into an electrical signal, and is typically a CMOS (Complementary Metal-Oxide-Semiconductor) or a CCD (Charge Coupled Device).

The image processing device 6 receives and recognizes the image of the driver 2 imaged by the IR camera 5, recognizes the driver's 2 face position, face direction, line of sight, eye open / closed degree, blink frequency, Detects physical information such as mouth open / closed degree and gestures. The image processing device 6 estimates the state of the driver 2 such as a look-ahead state or a dozing state from the detected physical information.
Further, the image processing device 6 detects the brightness of the image captured by the IR camera 5 and transmits it to the light emission control unit 13 as brightness information. The light emission control unit 13 performs more appropriate light emission control by adjusting the intensity of IR light based on the brightness information from the image processing device 6.

Next, a detailed configuration of the protection plate 11 will be described.
FIG. 3 is a block diagram illustrating a configuration example of the protection plate 11. FIG. 4 is a cross-sectional view illustrating an outline of a structural portion of the light projecting device 10 including the protection plate 11 and the IR light source unit 12. The IR light source unit 12 is installed so that IR light enters from the edge of the protective plate 11. The protection plate 11 includes an IR light irradiation unit 11 a that scatters and irradiates IR light from the IR light source unit 12, and a visible light transmission unit 11 b that transmits visible light from the meter display 4.

The IR light irradiation unit 11 a is a region obtained by processing a part of the surface of the protection plate 11. The IR light irradiation unit 11a guides the IR light incident from the edge of the protective plate 11 on which the IR light source unit 12 is installed, scatters and makes uniform, and irradiates the driver 2. In the IR light irradiation unit 11a, visible light from the meter display 4 is transmitted.
The processing of the IR light irradiation unit 11a is processing that changes the reflection tendency of the surface so that IR light incident from the edge is scattered. For example, a method of printing the dots 11c having a rough surface, and the surface with a laser wave. There are a method of damaging or a method of forming irregularities on the surface when the protective plate 11 is formed by pouring acrylic resin into the mold material. The surface on which the dot 11c pattern or the like is formed on the protective plate 11 may be only on the meter display 4 side, only on the driver 2 side, or both.

  The visible light transmitting portion 11 b is a region where the dot 11 c pattern or the like is not formed on the surface of the protection plate 11. The visible light transmission part 11b guides the IR light from the IR light source part 12, but does not scatter, so the IR light is not irradiated to the driver 2 from the visible light transmission part 11b. Visible light from the meter display 4 passes through the visible light transmission part 11b and is irradiated to the driver 2.

  FIG. 5 is a front view illustrating an example of the meter display 4 in which the light projecting device 10 is incorporated, and is a display surface viewed from the driver 2. A protective plate 11 is installed between the meter display 4 and the driver 2, and an IR light source unit 12 is installed on the lower edge of the protective plate 11. As the IR light source unit 12, for example, a plurality of IR-LEDs are arranged in an array along the lower edge of the protective plate 11. Although the IR light source unit 12 can be seen in FIG. 5, the IR light source unit 12 is actually installed inside the dashboard 3 and cannot be seen from the driver 2. As described above, as long as the IR light source unit 12 is an edge of the protective plate 11, the IR light source unit 12 may be installed on the upper side, the left side, or the right side without being limited to the lower side.

The meter display 4 displays display objects 41 to 45 such as a meter image indicating a vehicle speed, a meter image indicating an engine speed, or an image indicating a shift position.
Since the IR light irradiation unit 11a becomes translucent by processing for scattering IR light, it is desirable to arrange the IR light irradiation unit 11a in a region where the display objects 41 to 45 of the meter display 4 are not present. In the example of FIG. 4, the upper half of the meter display 4 without the display objects 41 to 45 is widely used as the IR light irradiation unit 11a. Thereby, IR light can be irradiated in a wide range. Moreover, in the example of FIG. 4, although the IR light irradiation part 11a is one continuous area, it may be divided into a plurality of areas.

  On the other hand, the visible light transmitting portion 11b is a region that does not irradiate IR light and transmits visible light of the display object of the meter display 4 as it is. Therefore, it is desirable to arrange the display objects 41 to 45 of the meter display 4 in an area. In general, in the meter display 4, the area with the display objects 41 to 45 is wider than the area without the display objects 41 to 45, so that the visible light transmission part 11b has a larger area than the area of the IR light irradiation part 11a. The area is larger.

  In this way, by providing the protection plate 11 with two types of regions, the IR light irradiation unit 11a and the visible light transmission unit 11b, the IR light can be transmitted to the driver 2 in a wide range without impairing the display on the meter display 4. Uniform irradiation is possible.

Next, a hardware configuration example of the light projecting device 10 will be described with reference to FIG.
The function of the light emission control unit 13 in the light projecting device 10 is realized by the processing circuit 100. That is, the light emission control unit 13 includes a processing circuit 100 for controlling the light emission of the IR light source unit 12. The processing circuit 100 may be dedicated hardware as shown in FIG. 6A, or may be a processor 101 that executes a program stored in the memory 102 as shown in FIG. Also good.
The IR light source unit 12 includes one or more IR-LEDs 12a and a drive circuit 12b for driving the IR-LEDs 12a. The drive circuit 12b controls the voltage applied to the IR-LED 12a and the timing of emitting the IR-LED 12a based on the light emission control signal transmitted from the processing circuit 100 or the processor 101.

  As shown in FIG. 6A, when the processing circuit 100 is dedicated hardware, the processing circuit 100 includes, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific). An integrated circuit (FPGA), a field-programmable gate array (FPGA), or a combination thereof is applicable. The function of the light emission control unit 13 may be realized by a plurality of processing circuits 100 or may be realized by a single processing circuit 100 collectively.

  As shown in FIG. 6B, when the processing circuit 100 is a processor 101, the function of the light emission control unit 13 is realized by software, firmware, or a combination of software and firmware. Software or firmware is described as a program and stored in the memory 102. The processor 101 implements the function of the light emission control unit 13 by reading and executing a program stored in the memory 102. In other words, the light emission control unit 13 includes a memory 102 for storing a program that, when executed by the processor 101, results in a process for controlling the light emission of the IR light source unit 12. This program can also be said to cause a computer to execute the procedure or method of the light emission control unit 13.

Here, the processor 101 is, for example, a CPU (Central Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor).
The memory 102 may be, for example, a nonvolatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically EPROM). Further, it may be a magnetic disk such as a hard disk or a flexible disk, or may be an optical disk such as a mini disk, CD (Compact Disc), or DVD (Digital Versatile Disc).

  Note that a part of the functions of the light emission control unit 13 may be realized by dedicated hardware, and a part may be realized by software or firmware. As described above, the light emission control unit 13 can realize the above-described functions by hardware, software, firmware, or a combination thereof.

Next, an operation example of the driver sensing system will be described with reference to FIG.
When the driver sensing system is activated, the light projecting device 10, the IR camera 5, and the image processing device 6 are activated, and a light emission control signal is output from the light emission control unit 13 of the light projection device 10 to the IR light source unit 12 (step ST1).
It should be noted that the start timing of the driver sensing system may be the timing when the ignition key of the vehicle is turned on, or the timing when the gear of the transmission is changed to the D (drive) range.
The light emission control signal at this time includes an instruction to switch the light emission of the IR light source unit 12 from off to on, and a voltage value or parameter corresponding to the intensity of the IR light. The light emission control unit 13 may use an initial set value as the intensity of the IR light immediately after being activated.

  The IR light source unit 12 receives the light emission control signal from the light emission control unit 13, and emits IR light based on the light emission control signal (step ST2). IR light emitted from the IR light source unit 12 is incident from the edge of the protective plate 11, scattered by the IR light irradiation unit 11 a, and irradiated to the driver 2.

  The IR camera 5 captures the image of the driver 2 irradiated with IR light and transmits the image to the image processing device 6 (step ST3).

  The image processing device 6 receives a captured image from the IR camera 5, and from this captured image, the driver's 2 face position, face direction, line of sight, eye open / closed degree, blinking frequency, mouth open / closed degree , Physical information such as a gesture is detected (step ST4).

Further, the image processing device 6 estimates the state of the driver 2 such as a look-ahead state or a dozing state from the detected physical information (step ST5). The image processing device 6 may estimate the state of the driver 2 using only physical information detected from the captured image, or may be obtained through this physical information and an in-vehicle network such as a CAN (Controller Area Network). You may estimate using vehicle information. The vehicle information is, for example, a vehicle speed, a brake operation amount, a gear position, or a steering angle of a steering wheel. Further, the image processing device 6 may estimate the seat belt wearing state of the driver 2 and the like.
Further, the image processing apparatus 6 may detect the physical information as described above and estimate the state of not only the driver 2 but also a passenger sitting in the passenger seat or the rear seat. Further, the image processing device 6 estimates whether the passenger sitting in the passenger seat or the rear seat is an adult or a child from the captured image, and uses the estimation result when, for example, the airbag to be activated is switched between an adult and a child It is also possible to do.

  Further, the image processing device 6 detects the brightness of the captured image from the IR camera 5, generates brightness information, and transmits the brightness information to the light emission control unit 13 of the light projecting device 10 (step ST6). The brightness information is, for example, the brightness value of the captured image.

  The light emission control unit 13 receives brightness information from the image processing device 6, calculates an adjustment amount of the intensity of IR light emitted from the IR light source unit 12 according to the brightness information, and emits light according to the adjustment amount. The voltage value or parameter included in the control signal is changed (step ST7). For example, when the luminance value notified as brightness information from the image processing device 6 is lower than a predetermined reference luminance value, the light emission control unit 13 increases the IR light irradiated to the driver 2 to increase the IR light. A light emission control signal in which a voltage value or a parameter corresponding to the light intensity is increased is generated. On the other hand, when the brightness value notified as the brightness information from the image processing device 6 is higher than the predetermined reference brightness value, the light emission control unit 13 reduces the IR light irradiated to the driver 2. A light emission control signal with a reduced voltage value or parameter is generated.

When generating the light emission control signal in step ST7, the light emission control unit 13 returns to step ST1 and outputs the light emission control signal to the IR light source unit 12.
The driver sensing system repeats the processes of steps ST1 to ST7 described above, and stops the activation when the ignition key of the vehicle is turned off or when the gear of the transmission is changed to a P (parking) range or the like.

  As described above, according to the first embodiment, the light projecting device 10 includes the protection plate 11 that protects the display surface of the meter display 4 installed in the vehicle interior 1, and the IR light source unit that makes IR light incident on the protection plate 11. 12 and the light emission control unit 13 that controls the light emission of the IR light source unit 12 and guides the IR light from the IR light source unit 12 through the protective plate 11 and irradiates the vehicle interior 1. Can be realized at low cost. Moreover, since the protection plate 11 of the meter display 4 is used as a light guide plate for IR light, a space for newly installing the light guide plate is not required.

Embodiment 2. FIG.
FIG. 8 is a block diagram showing a configuration example of the protection plate 11 of the light projecting device 10 according to Embodiment 2 of the present invention. The protection plate 11 includes an IR light irradiation unit 11a and a visible light transmission unit 11b. The IR light irradiation unit 11a further includes a first IR light irradiation unit 11a-1 and a second IR light irradiation unit 11a. -2.
In addition, since the structure of the light projector 10 and the driver sensing system which concern on Embodiment 2 is the same structure as the said Embodiment 1 except the protection board 11, description is abbreviate | omitted and FIG. 1 and FIG. 2 are used. .

  The first IR light irradiation unit 11a-1 is a region where dots 11c and the like having a rough surface are formed so as to irradiate IR light over a wide range. Here, the first IR light irradiation unit 11a-1 is non-directional.

On the other hand, the 2nd IR light irradiation part 11a-2 is an area | region which irradiates IR light which injected from the edge of the protection board 11 only in a specific direction. The directivity of the second IR light irradiation unit 11a-2 may be any strength, but is at least stronger than the first IR light irradiation unit 11a-1.
For example, as shown in FIG. 9A, the directivity may be increased by processing the shape of the surface of the protective plate 11. In FIG. 9A, the directivity is realized by printing dots 11d having a mirror surface on the surface of the protection plate 11 and adjusting the reflection direction of the IR light.
Alternatively, as shown in FIG. 9B, the directivity may be realized by installing a prism 11e between the protective plate 11 and the IR light source unit 12 and adjusting the emission direction from the prism 11e. . In the configuration example of FIG. 9B, the prism 11e becomes the second IR light irradiation unit 11a-2.

  FIG. 10 is a front view illustrating an example of the meter display 4 in which the light projecting device 10 according to the second embodiment is incorporated, and is a display surface viewed from the driver 2. The protection plate 11 includes a first IR light irradiation unit 11a-1, a second IR light irradiation unit 11a-2, and a visible light transmission unit 11b. In the example of FIG. 10, the first IR light irradiation unit 11a-1 is one continuous area, but it may be divided into a plurality of areas. Further, in the example of FIG. 10, the second IR light irradiation unit 11a-2 is divided into two regions on the left and right, and the second IR light irradiation unit 11a-2L and the second IR light irradiation unit 11a-2R are divided into two regions. However, it may be one continuous area. For example, the highly directional IR light irradiated from the second IR light irradiation unit 11a-2L illuminates the driver 2 from the left side and the strong directivity irradiated from the second IR light irradiation unit 11a-2R. The IR light illuminates the driver 2 from the right side.

  The first IR light irradiation unit 11a-1 emits IR light that illuminates the driver 2 over a wide area. Since the irradiation range is wide, even if the position of the face of the driver 2 moves greatly, the moved driver 2 can be irradiated with IR light. Therefore, even if the face position of the driver 2 moves greatly, the face of the driver 2 and the like can be detected by the image processing device 6.

  The second IR light irradiation unit 11a-2 irradiates directional IR light. Thereby, the accuracy of image recognition by the image processing device 6 when detecting the line of sight of the driver 2 can be improved. For example, a method called a corneal reflection method using a corneal reflection image is generally used for eye gaze detection.

Here, the corneal reflection method will be described with reference to FIGS. 11 and 12. FIG. 11 is a view of the eyeball of the driver 2 as viewed from above, and FIGS. 12A and 12B are views of the eyeball of the driver 2 as viewed from the front. A cornea reflection image is a reflection image on the cornea that is formed by irradiating IR light. The corneal reflection method is a method for estimating the direction of the line of sight based on the position of the pupil with respect to the position of the corneal reflection image using the corneal reflection image whose position does not change as a reference point.
When the corneal reflection method is used, if the outline of the corneal reflection image is clarified, the detection rate and detection accuracy of the corneal reflection image are increased. Therefore, it is desirable to use IR light having directivity rather than non-directional IR light.

  Moreover, it becomes possible for the light emission control part 13 to irradiate IR light with an arbitrary light emission pattern by causing the plurality of IR-LEDs of the IR light source part 12 to emit light individually. For example, in FIG. 10, a plurality of IR-LEDs arranged in an array along the lower edge of the protective plate 11 are divided into three LED groups 12-1, 12-2, 12-3. The light emission control unit 13 controls light emission for each group.

  In the configuration example of FIG. 10, the LED group 12-1 is a “first light source unit” that makes IR light incident on the first IR light irradiation unit 11a-1, and the LED groups 12-2 and 12-3 are included. This is a “second light source unit” that makes IR light incident on the second IR light irradiation unit 11a-2.

When the light emission controller 13 causes the IR-LED of the LED group 12-1 to emit light and the IR-LEDs of the remaining LED groups 12-2 and 12-3 are turned off, only the first IR light irradiation unit 11a-1 is absent. Irradiate directional IR light.
When the light emission control unit 13 causes the IR-LED of the LED group 12-2 to emit light and turns off the IR-LEDs of the remaining LED groups 12-1 and 12-3, only the second IR light irradiation unit 11a-2L is directed. Irradiate IR light.
When the light emission control unit 13 causes the IR-LED of the LED group 12-3 to emit light and turns off the IR-LEDs of the remaining LED groups 12-1 and 12-2, only the second IR light irradiation unit 11a-2R is directed. Irradiate IR light.

  When the corneal reflection method is used, by providing a plurality of second IR light irradiation units 11a-2 that irradiate directional IR light, a plurality of reference positions and pupil positions, that is, a plurality of corneal reflection image positions, The position of the pupil can be compared. Therefore, it is possible to improve the accuracy of line-of-sight detection.

Further, when disturbance light including IR light such as sunlight enters the vehicle interior 1, it is difficult to determine the difference between the corneal reflection image formed by the IR light of the IR light source unit 12 and the disturbance light by image processing. A false detection of the line of sight occurs.
Therefore, in the case where the difference between the cornea reflection image formed by the IR light of the IR light source unit 12 and the disturbance light cannot be discriminated in the image processing device 6, the second IR light that the light emission control unit 13 irradiates with IR light. By switching the irradiation units 11a-2L and 11a-2R, the position of the cornea reflection image can be changed. As a result, it is possible to discriminate between a cornea reflection image formed by IR light from the IR light source unit 12 and disturbance light, and it is possible to detect a line of sight strong against disturbance such as sunlight.
Or the light emission control part 13 can make a cornea reflection image appear or disappear by switching on and off of light emission of the 2nd IR light irradiation part 11a-2. This also makes it possible to discriminate between a cornea reflection image formed by IR light from the IR light source unit 12 and disturbance light.

  Next, an operation example of the light projecting device 10 according to the second embodiment will be described with reference to FIG. The flowchart shown in FIG. 13 shows the details of the operation performed by the light projecting apparatus 10 according to the second embodiment in step ST7 shown in FIG. 7 in the first embodiment. The light projecting device 10 according to the second embodiment performs the same operation as that of the first embodiment in steps ST1 to ST6, and thus illustration and description thereof are omitted.

When the light emission control unit 13 is activated in step ST1 shown in FIG. 7, first, a light emission control signal for causing the IR-LED of the LED group 12-1 to emit light, or the LED groups 12-1, 12-2, 12-3. A light emission control signal for causing all of the IR-LEDs to emit light is output to the IR light source unit 12.
Thereafter, similarly to step ST7 shown in FIG. 7, the light emission control unit 13 receives the brightness information from the image processing device 6, and the intensity of the IR light emitted from the IR light source unit 12 according to the brightness information. And the voltage value or parameter included in the light emission control signal is changed according to the adjustment amount (step ST7-1).

  In the second embodiment, the image processing device 6 transmits not only brightness information but also recognition result information. The image processing device 6 generates recognition result information indicating whether the face of the driver 2 has been detected from the image captured by the IR camera 5 and transmits the recognition result information to the light emission control unit 13 of the light projecting device 10.

The light emission control unit 13 receives the recognition result information from the image processing device 6, and determines whether or not the face of the driver 2 is detected in the image processing device 6 (step ST7-2).
When the face of the driver 2 is not detected in the image processing device 6 (step ST7-2 “NO”), the light emission control unit 13 generates a light emission control signal that causes the IR-LEDs of the LED group 12-1 to emit light. (Step ST7-3). Thereby, non-directional IR light is irradiated in a wide range from the first IR light irradiation unit 11a-1. Accordingly, the image processing device 6 can detect the position of the face of the driver 2 and estimate the state. In addition, a position where a cornea reflection image can be formed can be predicted from the detected face position.
In step ST7-3, the light emission control unit 13 may cause all of the IR-LEDs of the LED groups 12-1, 12-2, and 12-3 to emit light so that the line of sight can be detected by the cornea reflection method.

  The light emission control unit 13 emits at least one of the LED group 12-2 or the LED group 12-3 when the face of the driver 2 is detected in the image processing apparatus 6 (step ST7-2 “YES”). A signal is generated (step ST7-4). Thereby, IR light with directivity is irradiated from at least one of the second IR light irradiation unit 11a-2L or the second IR light irradiation unit 11a-2R. Therefore, the image processing device 6 can detect the direction of the line of sight from a cornea reflection image with a clear outline.

  After step ST7-3 or step ST7-4, the light emission control unit 13 returns to step ST1 in FIG. 7 and repeats the processes of steps ST1 to ST7. Thereby, the light emission control unit 13 first causes the LED group 12-1 to emit light according to a predetermined light emission pattern and irradiates non-directional IR light from the first IR light irradiation unit 11a-1. The LED groups 12-2 and 12-3 can emit light to emit IR light having directivity from the second IR light irradiation unit 11a-2.

In step ST7-4, the light emission control unit 13 determines which of the second IR light irradiation unit 11a-2L or the second IR light irradiation unit 11a-2R based on the recognition result information from the image processing device 6. It may be determined whether to irradiate IR light.
For example, whether or not the image processing device 6 could detect the driver 2's face as the recognition result information, and whether the difference between the cornea reflection image formed by the IR light from the IR light source unit 12 and the disturbance light could be discriminated. Information indicating whether or not is generated is transmitted to the light emission control unit 13 of the light projecting device 10.
It is assumed that the light emission control unit 13 of the light projecting device 10 irradiates IR light having directivity from the second IR light irradiation unit 11a-2L in the current step ST7-4. If the image processing apparatus 6 cannot determine the difference between the corneal reflection image by the IR light irradiated from the second IR light irradiation unit 11a-2L and the disturbance light, in the next step ST7-4, the light emission is performed. The control unit 13 stops the irradiation from the second IR light irradiation unit 11a-2L and causes the second IR light irradiation unit 11a-2R to perform irradiation. Although the position of the disturbance light reflected in the eyes of the driver 2 does not change, the position of the cornea reflection image by the IR light is changed by switching from the second IR light irradiation unit 11a-2L to the second IR light irradiation unit 11a-2R. Changes, the image processing apparatus 6 can determine the correct position of the corneal reflection image.

  When the image processing device 6 cannot discriminate the difference between the corneal reflection image by the IR light from the second IR light irradiation unit 11 a-2 and the disturbance light, the light emission control unit 13, for example, After the light emission is extinguished and only the disturbance light is detected, the position of the disturbance light is discriminated by the image processing apparatus 6, and then the IR light is irradiated from the second IR light irradiation unit 11a-2 to enable the line-of-sight detection.

  As described above, according to the second embodiment, the IR light irradiation unit 11a includes the first IR light irradiation unit 11a-1 and the second IR having higher directivity than the first IR light irradiation unit 11a-1. Since the light irradiation unit 11a-2 is configured, it is possible to irradiate IR light over a wide range from the first IR light irradiation unit 11a-1, and even if the position of the face of the driver 2 changes greatly, The state of the driver 2 can be estimated. In addition, IR light having directivity can be irradiated from the second IR light irradiation unit 11a-2, and the outline of the corneal reflection image becomes clear and the accuracy of line-of-sight detection is improved.

  Further, according to the second embodiment, the IR light source unit 12 is directed to the LED group 12-1 that makes the IR light incident on the first IR light irradiation unit 11a-1 and the second IR light irradiation unit 11a-2. The light emission control unit 13 causes the LED group 12-1 to emit light according to a predetermined light emission pattern, and the first IR light irradiation unit 11a. -1 after irradiating the IR light, the LED groups 12-2 and 12-3 are made to emit light and the IR light is irradiated from the second IR light irradiating unit 11a-2. If the position of the cornea changes greatly and the position of the cornea reflection image cannot be detected, the position of the face after the movement can be detected by first irradiating IR light over a wide range, and the position where the cornea reflection image can be predicted is predicted Can be possible.

  Further, according to the second embodiment, the protection plate 11 includes a plurality of second IR light irradiation units 11a-2, and the IR light source unit 12 applies IR to the plurality of second IR light irradiation units 11a-2. The light emission control unit 13 includes a plurality of LED groups that receive light, and the light emission control unit 13 irradiates IR light by switching light emission of the plurality of LED groups 12-2 and 12-3 according to a predetermined light emission pattern. Since the two IR light irradiation units 11a-2L and 11a-2R are switched, it becomes easy to discriminate between the corneal reflection image and the disturbance light, and the image processing apparatus 6 can detect the line of sight strong against disturbance such as direct sunlight. it can.

In addition, although the driver sensing system of Embodiment 1, 2 was used for imaging | photography of the driver 2 of a vehicle, you may use it for the imaging | photography of the driver | operator of the moving body containing a railroad, a ship, an aircraft, etc.
In the first and second embodiments, the meter display 4 installed on the dashboard 3 is exemplified as the display device. However, any display device protected by a protective plate such as a display installed on the center console may be used. Good.
In the first and second embodiments, the IR light source unit 12 that emits IR light of 800 nm to 950 nm is used as the illumination for imaging the driver 2, but the light source unit that emits infrared light including IR light is used. May be.

  In the present invention, within the scope of the invention, any combination of each embodiment, any component of each embodiment can be modified, or any component of each embodiment can be omitted.

  1 vehicle interior, 2 driver, 3 dashboard, 4 meter display (display device), 5 IR camera, 6 image processing device, 10 projector, 11 protection plate, 11a IR light irradiation unit (infrared light irradiation unit) 11a-1 First IR light irradiation unit (first infrared light irradiation unit), 11a-2, 11a-2L, 11a-2R Second IR light irradiation unit (second infrared light irradiation unit) , 11b Visible light transmission part, 11c, 11d dots, 11e prism, 12 IR light source part (light source part), 12a IR-LED, 12b drive circuit, 12-1 LED group (first light source part), 12-2, 12-3 LED group (second light source unit), 13 light emission control unit, 41 to 45 display object, 51 lens, 52 IR transmission filter, 53 image sensor, 100 processing circuit, 101 processor, 102 meg Li.

Claims (10)

A protective plate for protecting the display surface of the display device installed in the passenger compartment;
A light source unit that makes infrared light incident on the protective plate;
A light projection device comprising: a light emission control unit that controls light emission of the light source unit, guides infrared light from the light source unit with the protective plate, and irradiates the vehicle interior.   The said protective plate has an infrared light irradiation part which scatters and irradiates the infrared light from the said light source part, and a visible light transmission part which permeate | transmits the visible light from the said display apparatus, It is characterized by the above-mentioned. The light projecting device according to 1.   The light projecting device according to claim 2, wherein an area of the visible light transmitting portion is larger than an area of the infrared light irradiation portion.   The infrared light irradiation unit includes a first infrared light irradiation unit and a second infrared light irradiation unit having higher directivity than the first infrared light irradiation unit. The light projecting device according to claim 2 or 3. The light source unit includes a first light source unit that inputs infrared light to the first infrared light irradiation unit, and a second light source unit that inputs infrared light to the second infrared light irradiation unit. Have
The light projection device according to claim 4, wherein the light emission control unit controls light emission of the first light source unit and the second light source unit according to a predetermined light emission pattern.   The light emission control unit causes the first light source unit to emit light according to a predetermined light emission pattern and irradiate infrared light from the first infrared light irradiation unit, and then causes the second light source unit to The light projecting device according to claim 5, wherein the light is emitted and irradiated with infrared light from the second infrared light irradiation unit. The protective plate has a plurality of the second infrared light irradiation sections,
The light source unit includes a plurality of the second light source units that make infrared light incident on the plurality of second infrared light irradiation units,
The light emission control unit switches the second infrared light irradiation unit that emits infrared light by switching light emission of a plurality of the second light source units according to a predetermined light emission pattern. The light projecting device according to claim 5.   8. The light projection according to claim 4, wherein the second infrared light irradiating part has enhanced directivity by shape processing of the surface of the protective plate. 9. apparatus.   The light projecting device according to claim 4, wherein the second infrared light irradiation unit is a prism installed on the protective plate.   The light projecting device according to claim 1, wherein the display device is a meter display installed in front of a driver's seat.

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