JPWO2016152637A1 - Image display device - Google Patents

Abstract

An object of the present invention is to provide an image display device that does not require drive control of a mechanical mechanism for adjusting display luminance and color tone, is excellent in durability, and can display a highly accurate image. The image display device (1) includes a driver state detection unit (12) that detects the driver's state, and an original image prepared in advance based on the driver state detected by the driver state detection unit (12). A parameter setting unit (13) for setting parameters for adjusting information, and an image for adjusting the original image information based on the parameters set by the parameter setting unit (13) to generate image information of an image to be displayed An information generation unit (15) and an image forming unit (18) that modulates light from the light source based on the image information generated by the image information generation unit (15).

Description

  The present invention relates to an image display device such as a head-up display.

  2. Description of the Related Art In recent years, a head-up display is known in which a display image is projected onto a window shield of a vehicle using a holographic optical element so that a driver can visually recognize a virtual image of the display image.

  In such a head-up display, as shown in FIG. 7, when the driver views a virtual image from the front, the brightness K1 of the virtual image visually recognized by the driver is uniform. On the other hand, when the driver sees the virtual image from the left side, the luminance K2 of the virtual image visually recognized by the driver increases toward the right. Further, when the driver sees the virtual image from the right side, the luminance K3 of the virtual image visually recognized by the driver increases as it goes to the left. As described above, when the driver visually recognizes the virtual image, the driver visually recognizes the virtual image having different luminance depending on the posture or the physique of the driver.

  Patent Document 1 relates to a head-up display, and integrates a display device and a light reflection portion that reflects light emitted from the display device, and adjusts the angle of the light reflection portion so that the driver can visually recognize the region. A configuration including an angle adjusting mechanism for diffracting light is disclosed. In such a head-up display, the angle of the light reflecting portion using the hologram element can be changed based on a change in the driver's line-of-sight position, and the diffracted light can be diffracted to the driver's visual recognition position. Regardless of the posture or physique, the display brightness and color tone can be kept constant.

Japanese Patent Laid-Open No. 10-278630

  However, in Patent Document 1, since the display brightness and color tone are adjusted by a mechanical mechanism, the drive control of the mechanism is complicated and there is a disadvantage that the mechanical life must be taken into account. . In Patent Document 1, when used in a vehicle, it is necessary to project a virtual image onto a front window having a curvature. Therefore, when the projection angle of the virtual image is changed by a mechanical mechanism, the projected virtual image is distorted. There is a disadvantage.

  The present invention has been made in view of such circumstances, and its purpose is to eliminate the need for drive control of a mechanical mechanism for adjusting display luminance and color tone, and is excellent in durability and suitable for the user's condition. An object of the present invention is to provide an image display device capable of displaying an accurate image.

  An image display apparatus according to the present invention includes a user state detection unit that detects a user state, and parameters for adjusting original image information prepared in advance based on the user state detected by the user state detection unit. A parameter setting unit to be set, an image information generation unit that adjusts the original image information based on the parameters set by the parameter setting unit, and generates image information of an image to be displayed; and the image information generation unit And an image forming unit that modulates light from the light source based on the generated image information.

  According to this configuration, the display brightness and color tone of an image are adjusted without using a mechanical mechanism by detecting the state of the user and adjusting the original image information based on parameters set based on the detection result. In addition, various adjustments of the image can be made. Thereby, a high-quality image suitable for the user's condition can be provided.

  Preferably, in the image display device of the present invention, the image forming unit generates hologram diffracted light by phase-modulating the light based on the image information generated by the image information generating unit.

  According to this configuration, hologram diffraction in which the display brightness and color tone are adjusted without using a mechanical mechanism by detecting the state of the user and adjusting the original image information based on parameters set based on the detection result. Light can be obtained and a virtual image can be displayed by the obtained hologram diffraction light.

  Preferably, in the image display device of the present invention, the parameter sets at least one of an image shape, luminance, number of used pixels, and gradation indicated by the original image information.

  According to this configuration, various attributes of the original image information are adjusted by adjusting the original image information with parameters that set at least one of the shape, brightness, number of used pixels, and gradation of the image indicated by the original image information. Thus, it is possible to display an image with high accuracy.

  Preferably, in the image display device of the present invention, the parameter setting unit sets the parameter for each of a plurality of image blocks defined in the image, and the image information generation unit uses the parameter setting unit to The original image information is adjusted based on the parameters set for each image block.

  According to this configuration, by setting parameters for each image block and adjusting the image quality, different adjustments are performed for each image block, thereby enabling display with higher accuracy.

  Preferably, in the image display device of the present invention, the image forming unit modulates the light based on the image information generated by the image information generating unit, and the image is displayed at a different timing for each of the plurality of image blocks. Is to modulate.

  According to this configuration, it is possible to adjust the image quality by setting parameters for each image block that displays images at different timings.

  Preferably, in the image display device of the present invention, the parameter setting unit sets the parameter different from the previous one when the image quality evaluation value of the image generated by the image forming unit does not satisfy a predetermined standard. is there.

  According to this configuration, by changing the parameters until the image quality evaluation value of the image satisfies a predetermined criterion, an image with good image quality is generated and displayed.

  Preferably, in the image display device of the present invention, the image quality evaluation value is a value obtained from at least one of red luminance, green luminance, and blue luminance in the image.

  According to this configuration, an image having good red luminance, green luminance, and blue luminance in the image is displayed.

  ADVANTAGE OF THE INVENTION According to this invention, the drive control of the mechanical mechanism for adjusting a display brightness | luminance and a color tone is unnecessary, and it is excellent in durability and can provide the image display apparatus which can display a highly accurate image.

1 is a functional block diagram of an image display device 1 according to an embodiment of the present invention. It is a figure which shows the table memorize | stored in the positional information output from the driver | operator state detection part shown in FIG. 1, and the parameter memory shown in FIG. It is a figure which shows the several image block prescribed | regulated in the image displayed by the image display apparatus of embodiment of this invention. It is a flowchart which shows operation | movement of the image display apparatus of embodiment of this invention. It is a conceptual diagram which shows operation | movement of the image display apparatus of embodiment of this invention. It is a figure explaining the principle in which a driver | operator visually recognizes a virtual image. It is a figure which shows the brightness | luminance according to a driver | operator's position.

Hereinafter, an image display apparatus according to an embodiment of the present invention will be described.
<Configuration of image display device>
The configuration of the image display apparatus 1 according to the embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 3.
The image display device 1 is a head-up display and provides an appropriate image according to the state of the driver (user).

  The image display device 1 according to the embodiment of the present invention is used by being mounted on a vehicle (moving body). As shown in FIG. 1, the image display device 1 includes a parameter memory 11, a driver state detection unit 12, a parameter setting unit 13, an image memory 14, an image information generation unit 15, a light emission control unit 16, The light emitting unit 17, the image forming unit 18, the Fourier transform lens 19, the light receiving unit 20, the light diffusing unit 21, and the light reflecting unit 22 are included.

The parameter memory 11 stores a parameter selection table shown in FIG.
As shown in FIG. 2B, the parameter selection table stores parameters for setting the image shape k2, the luminance k3, the number of used pixels k4, and the gradation k5, which are associated with the face position information k1. Yes.

The parameters for setting the shape of the image are parameters for setting the rotation k21, the direction k22, and the distortion k23. The parameters for setting the image luminance k3 are parameters for setting the image block k31 to be changed, the luminance increase rate k32, and the APC luminance k33.
The parameter table is determined by adjusting the image quality while changing the parameters, for example, by actual measurement in advance.

The driver state detection unit 12 detects the position of the driver's face and outputs position information indicating the detected face position to the parameter setting unit 13. The driver state detection unit 12 detects the position of the driver's face by analyzing an image obtained by photographing the driver with a camera, for example. Here, as shown in FIG. 2A, the face position information k1 is the position k11 on the x axis, the position k12 on the y axis, and the z axis in the x, y, and z axes of the three-axis orthogonal coordinate system. This is face position information specified by the upper position k13.
Further, the driver state detection unit 12 may identify the movement of the driver's eyeball and detect the line-of-sight direction.

  The parameter setting unit 13 refers to the parameter selection table stored in the parameter memory 11 and sets the parameter associated with the position of the position information input from the driver state detection unit 12 for each of a plurality of image blocks. Select and set.

The parameter setting unit 13 obtains an image quality evaluation value of the image quality to be displayed based on the signal input from the light receiving unit 20. The parameter setting unit 13 refers to the parameter selection table stored in the parameter memory 11 when the obtained image quality evaluation value does not satisfy the predetermined standard, and sets the position information position input from the driver state detection unit 12. Among the associated parameters, a parameter different from the previously set parameter is selected and set for each of a plurality of image blocks.
Here, as shown in FIG. 3, the image to be displayed is composed of a plurality of image blocks 0, 1, and 2 having different display positions defined in the image.

  The parameter setting unit 13 outputs the set parameters to the image information generation unit 15.

  The image memory 14 prepares and stores original image information of a display image in advance. The original image information is, for example, JPEG (Joint Photographic Experts Group) image information.

The image information generation unit 15 reads the original image information stored in the image memory 14, and uses the parameters set for each of the plurality of image blocks input from the parameter setting unit 13 to read the read original image information for each image block. The image information of the image to be displayed is generated. The image information generation unit 15 outputs the generated image information to the image forming unit 18.
The adjustment is performed for the shape, brightness, number of used pixels, and gradation R / G / B defined in the parameters.

  The light emission control unit 16 feedback-controls the output of the light emitting unit 17 based on a signal corresponding to the light intensity input from the light receiving unit 20 so that the light intensity becomes the specified light intensity.

  The light emitting unit 17 that is a light source includes, for example, three laser diodes (LD) of R (red), G (green), and B (blue) for displaying a virtual image. The light emitting unit 17 irradiates the image forming unit 18 with light from each laser. The light output of the laser of the light emitting unit 17 is controlled by the light emission control unit 16. Note that the number of lasers is not particularly limited.

The image forming unit 18 generates hologram diffracted light by phase-modulating the light incident from the light emitting unit 17 based on the image information input from the image information generating unit 15. The image forming unit 18 irradiates the Fourier transform lens 19 with the generated hologram diffracted light.
A series of flows from the image information generation unit 15 to the image forming unit 18 is supplied at different timings in which a plurality of image blocks are consecutive.
The image forming unit 18 modulates the image blocks at different timings for each of the plurality of image blocks to obtain hologram diffracted light, and irradiates the Fourier transform lens 19 with the hologram diffraction light.

  The image forming unit 18 becomes an image display screen. The image forming unit 18 is, for example, LCOS (Liquid Crystal on Silicon).

  Here, the LCOS is generally provided with MOS transistors and pixel electrodes in a matrix on a silicon CMOS substrate, and an optically transparent common electrode is provided on the pixel electrode facing surface of the substrate disposed opposite to the CMOS substrate. A reflective liquid crystal display element comprising a liquid crystal layer provided and sealed between these two substrates.

  Note that the image forming unit 18 may use a transmissive LCD or the like instead of the LCOS.

  The Fourier transform lens 19 Fourier transforms the hologram diffracted light from the image forming unit 18 to form an image on the light diffusion unit 21.

  The light receiving unit 20 is a photodiode (PD), is provided around the light diffusing unit 21, and is irradiated with a luminance adjustment image corresponding to the luminance adjustment image information included in the image information generated by the image information generation unit 15. It is provided at the position. The light receiving unit 20 outputs a signal corresponding to the received light intensity to the light emission control unit 16.

The light diffusing unit 21 diffuses the hologram diffracted light incident via the Fourier transform lens 19.
The light diffusing unit 17 has, for example, a disk-like transmissive optical component (optical element). Among the optical components, when light passes through an optical surface crossing the optical path, an optical path difference (phase difference) of about λ / 2 occurs depending on the location. The optical component is driven to rotate about an axis substantially parallel to the optical axis. The light diffusing unit 17 suppresses spectral coherence of light that is visually recognized and causes image quality degradation.

  The light reflecting section 22 is composed of a magnifying mirror, and projects the light diffused from the light diffusing section 21 on the window shield glass after performing magnifying and distortion correction. The window shield glass is provided as a vehicle windshield.

  The light reflecting unit 22 enlarges and corrects the display image corresponding to the light from the light diffusing unit 21, projects it toward the window shield glass 51, and reflects this display image in the direction of the driver's eyes 55. As a result, the display image is formed in front of the driver as a virtual image 57 as shown in FIG. 6 so that the driver can visually recognize the display image.

<Operation of image display device>
The operation of the image display apparatus 1 according to the embodiment of the present invention will be described in detail below with reference to FIGS.
FIG. 4 is a flowchart showing the operation of the image display apparatus 1 according to the embodiment of the present invention.

  First, the image information generation unit 15 reads original image information from the image memory 14 for each image block (S1).

  Next, the parameter setting unit 13 refers to the parameter selection table stored in the parameter memory 11, and position information indicating the position of the driver's face as the driver state input from the driver state detection unit 12. And the parameter corresponding to the image block to be displayed are selected and set (S2).

Next, the image information generation unit 15 reads out and acquires the original image information stored in the image memory 14, and in step S11 shown in FIG. 5 according to the parameters acquired from the parameter setting unit 13 in step S12 shown in FIG. The acquired original image information is adjusted to generate image information of an image to be displayed (S3).
The image information generation unit 15 overwrites the amplitude G ₀ (x, y) of the original image information based on the parameter acquired from the parameter setting unit 13 in step S13 shown in FIG. Thereby, the image information generation unit 15 changes the intensity of red (R), the intensity of green (G), the intensity of blue (B), and the like.

Next, as shown in FIG. 4, the image forming unit 18 phase-modulates the light from the emitted light 17 based on the image information input from the image information generating unit 15 to generate hologram diffracted light and Fourier transform. The lens 19 is irradiated (S4).
The light receiving unit 20 receives light from the Fourier transform lens 19 (S4).

  Then, the light diffusing unit 21 diffuses the hologram diffracted light. Further, as shown in FIG. 6, the light reflecting portion 22 enlarges and directs the light diffused light from the light diffusing portion 21 and projects it onto the window shield glass 51.

  The light projected from the light reflecting portion 22 onto the window shield glass 51 is reflected by the window shield glass 51 and reaches the viewpoint 55 of the driver (passenger). The driver can visually recognize a virtual image (virtual image display image) 57 obtained by enlarging an image corresponding to the light from the light reflecting portion 22 at a point in front of the window shield glass 51.

  Here, the display surface of the image forming unit 18, the image formed on the diffusion region of the light diffusion unit 21, and the virtual image 57 are in a conjugate relationship.

  Further, as shown in FIG. 4, the parameter setting unit 13 obtains the image quality evaluation value of the image to be displayed, and determines whether or not the obtained image quality evaluation value is larger than the reference value (S5). Specifically, the parameter setting unit 13 has an R / G / B ratio, which is an image quality evaluation value obtained from the luminance of red (R), the luminance of green (G), and the luminance of blue (B), greater than the threshold value. It is determined whether or not.

Specifically, as shown in FIG. 5, the parameter setting unit 13 gives a random phase to the image information generated by the image information generation unit 15 (S14), and performs inverse Fourier transform (h _n ′ (x ′, y ′) = FT ⁻¹ [g _n-1 (x, y)]) (S15), and the amplitude is normalized (h _n (x ′, y ′) = h _n ′ (x ′, y ′) / | H _n ′ (x ′, y ′) |) is performed (S16), and Fourier transform g _n ′ (x, y) = FT [h _n (x ′, y ′)] is performed (S17).
Then, the parameter setting unit 13 performs the above-described image quality evaluation on the image obtained in step 17.

  If the image quality evaluation value is larger than the threshold value (S5: Yes), the parameter setting unit 13 determines that the image quality is good because the image quality evaluation value satisfies the standard, and does not change the set parameter.

  On the other hand, as shown in FIG. 4, when the image quality evaluation value is equal to or less than the threshold (S5: No), the parameter setting unit 13 determines that the image quality is poor because the image quality evaluation value does not satisfy the standard, and FIG. A parameter different from the previously set parameter among the parameters associated with the position of the position information input from the driver state detection unit 12 with reference to the parameter selection table stored in the parameter memory 11 in S13 shown in FIG. Is selected and set for each of a plurality of image blocks (S2).

  Thus, according to the present embodiment, a driver state detection unit 12 that detects the driver's state, and an original image prepared in advance based on the driver state detected by the driver state detection unit 12 A parameter setting unit 13 that sets parameters for adjusting information, and an image information generation unit 15 that adjusts original image information based on the parameters set by the parameter setting unit 13 and generates image information of an image to be displayed. And an image forming unit 18 that generates and displays an image by modulating light from the light source based on the image information generated by the image information generating unit 15 to detect the state of the driver, Since the original image information is adjusted based on the parameters set based on the detection result, the display brightness and color tone of the image are adjusted without using a mechanical mechanism, and various adjustments of the image are performed. Possible to be. Thereby, even if the position of the driver's head is different, a high-quality image can be provided to the driver.

  In addition, according to the present embodiment, the image forming unit 18 detects the driver's state because the light is phase-modulated to generate hologram diffracted light based on the image information generated by the image information generating unit 15. Since the original image information can be adjusted based on the parameters set based on the detection result, the hologram diffracted light obtained by adjusting the display brightness and color tone without using a mechanical mechanism is obtained. A virtual image can be displayed by diffracted light.

  Further, according to the present embodiment, the parameter sets at least one of the shape, brightness, number of used pixels, and gradation of the image indicated by the original image information, so that the image indicated by the original image information Since the original image information is adjusted by a parameter for setting at least one of shape, brightness, number of used pixels, and gradation, various attributes of the original image information can be adjusted to display an image with high accuracy.

  Further, according to the present embodiment, the parameter setting unit 13 sets parameters for each of a plurality of image blocks defined in the image, and the image information generation unit 15 uses the parameter setting unit 13 for each of a plurality of image blocks. By adjusting the original image information based on the parameters set in, the image quality is adjusted by setting the parameters for each image block, so different adjustments can be made for each image block to enable more accurate display. is there.

  Further, according to the present embodiment, the image forming unit 18 modulates light based on the image information generated by the image information generating unit 15 and displays an image at a different timing for each of a plurality of image blocks. It is possible to adjust the image quality by setting parameters for each image block that displays an image at different timings.

  Further, according to the present embodiment, when the image quality evaluation value of the image generated by the image forming unit 18 does not satisfy a predetermined standard, the parameter setting unit 13 sets a parameter different from the previous one, thereby By changing the parameters until the image quality evaluation value satisfies a predetermined standard, an image with good image quality can be displayed.

  Further, according to the present embodiment, the evaluation value is a value obtained from the red luminance, the green luminance, and the blue luminance in the image, so that the red luminance, the green luminance, and the blue in the image are obtained. An image with good brightness can be displayed.

The present invention is not limited to the embodiment described above.
That is, those skilled in the art may make various modifications, combinations, sub-combinations, and alternatives for the components of the above-described embodiment within the technical scope of the present invention or an equivalent scope thereof.

  Specifically, the image display device 1 is not limited to being mounted on a vehicle and displaying an image on a front window, but may be installed in a room other than the vehicle to display an image on a window.

  The parameter selection table shown in FIG. 2 is an example, and parameters may be set using a parameter selection table that stores parameters other than the parameters stored in the parameter selection table shown in FIG.

  In the above-described embodiment, the present invention is applied to a head-up display, and a driver is exemplified as a user of the present invention. However, the present invention may be applied to a display other than a vehicle.

Also, the shape and number of image blocks shown in FIG. 3 are arbitrary.
Further, the feedback processing for evaluating the image quality of the image shown in FIG. 5 may not be performed.

  The present invention can be applied to, for example, a head-up display.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 11 Parameter memory 12 Driver state detection part 13 Parameter setting part 14 Image memory 15 Image information generation part 16 Light emission control part 17 Light emission part 18 Image formation part 19 Fourier transform lens 20 Light receiving part 21 Light diffusion part 22 Light reflection Part 51 Window shield glass 55 Viewpoint 57 Virtual image

Claims (7)

A user state detection unit for detecting a user state;
A parameter setting unit for setting parameters for adjusting original image information prepared in advance based on the user state detected by the user state detection unit;
An image information generation unit that adjusts the original image information based on the parameters set by the parameter setting unit and generates image information of an image to be displayed;
An image forming unit that modulates light from a light source based on the image information generated by the image information generating unit;
An image display apparatus. The image forming unit includes:
Based on the image information generated by the image information generation unit, the light is phase-modulated to generate hologram diffracted light,
The image display device according to claim 1. The parameter is
At least one of the shape, brightness, number of used pixels, and gradation of the image indicated by the original image information is set.
The image display device according to claim 1. The parameter setting unit
Setting the parameter for each of a plurality of image blocks defined in the image;
The image information generation unit
Adjusting the original image information based on the parameters set for the plurality of image blocks by the parameter setting unit;
The image display apparatus in any one of Claims 1-3. The image forming unit includes:
Based on the image information generated by the image information generation unit, the light is modulated, and the modulation is performed at different timings for each of the plurality of image blocks.
The image display device according to claim 4. The parameter setting unit
When the image quality evaluation value of the image generated by the image forming unit does not satisfy a predetermined standard, the parameter different from the previous time is set.
The image display device according to claim 1. The image quality evaluation value is
It is a value obtained from at least one of red luminance, green luminance, and blue luminance in the image,
The image display device according to claim 6.

Images