Image source in head-up display device, head-up display device and head-up display system

Abstract

The utility model provides an image source in head-up display equipment, the head-up display equipment and a head-up display system. The image source in the head-up display device comprises a light source part, the light source part is configured to emit backlight, the backlight comprises a first wave crest, a second wave crest and a third wave crest, and the first wave crest, the second wave crest and the third wave crest are located in wave bands corresponding to visible light of different colors; the display panel is located on the light emitting side of the light source part and is configured to convert backlight into image light and then output the image light. The image source in the head-up display device can improve the backlight color rendering.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to an image source in a head-up display device, a head-up display device, and a head-up display system. Background Art

[0002] Head-up display (HUD) technology refers to a reflective optical design that projects light from an image source onto an imaging window (imaging board, windshield, etc.) to form a virtual image, in which driving-related information such as vehicle speed is displayed. This avoids distraction caused by users looking down at the dashboard while driving, allowing users to view the virtual image within their field of vision, improving driving safety while also providing a better driving experience.

[0003] In the image source, a light source unit is used to provide backlight for the display panel. In the prior art, the color expression capability (ie, color rendering) of the backlight emitted by the light source unit is relatively weak. Utility Model Content

[0004] The present disclosure aims to solve at least one of the technical problems existing in the prior art, and proposes an image source in a head-up display device, a head-up display device, and a head-up display system.

[0005] In order to achieve the above objective, according to one aspect of the present disclosure, an image source in a head-up display device is provided, comprising:

[0006] A light source unit, the light source unit is configured to emit backlight, the backlight includes a first wave peak, a second wave peak and a third wave peak, wherein the first wave peak, the second wave peak and the third wave peak are located in wave bands corresponding to visible light of different colors;

[0007] The display panel is located at the light-emitting side of the light source unit and is configured to convert the backlight into image light for output.

[0008] In some optional embodiments, the first wave peak, the second wave peak and the third wave peak are respectively located in the blue light band, the green light band and the red light band.

[0009] In some optional embodiments, the backlight satisfies at least one of the following:

[0010] The peak wavelength of the first wave peak is between 435nm and 455nm;

[0011] The peak wavelength of the second wave peak is between 510nm and 550nm;

[0012] The peak wavelength of the third wave peak is between 610nm and 660nm.

[0013] In some optional embodiments, the backlight satisfies at least one of the following:

[0014] The peak wavelength of the first wave peak is between 440nm and 450nm;

[0015] The peak wavelength of the second wave peak is between 520nm and 540nm;

[0016] The peak wavelength of the third wave peak is between 620nm and 650nm.

[0017] In some optional embodiments, the backlight satisfies at least one of the following:

[0018] The ratio of the irradiance integral value of the blue light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.3 and less than or equal to 0.5;

[0019] The ratio of the irradiance integral value of the green light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.25 and less than or equal to 0.45;

[0020] A ratio of an irradiance integral value of a red light component in the backlight to an irradiance integral value of a white light component in the backlight is greater than or equal to 0.2 and less than or equal to 0.4.

[0021] In some optional embodiments, the white light in the backlight has a horizontal coordinate greater than or equal to 0.25 and less than or equal to 0.30 in the chromaticity diagram, and a vertical coordinate greater than or equal to 0.23 and less than or equal to 0.25.

[0022] In some optional embodiments, the electro-optical efficiency of the light source portion is greater than 70 lm / W.

[0023] In some optional embodiments, the transmittance of the display panel to the backlight is greater than or equal to 5%.

[0024] In some optional embodiments, the light source unit includes at least one light source element, and each of the light source elements includes:

[0025] A light-emitting chip, wherein the light-emitting chip is configured to emit excitation light;

[0026] The light-emitting layer is located at the light-emitting side of the light-emitting chip, and contains green phosphor and red phosphor.

[0027] In some optional embodiments, a ratio of an area of ​​the light-emitting layer to an area of ​​the light source portion is greater than or equal to 1 and less than or equal to 1.5.

[0028] In some optional embodiments, the backlight satisfies at least one of the following:

[0029] The half-peak width of the spectrum corresponding to the first peak is less than or equal to 40 nm;

[0030] The half-peak width of the spectrum corresponding to the second peak is less than or equal to 70 nm;

[0031] The half-peak width of the spectrum corresponding to the third wave peak is less than or equal to 40 nm.

[0032] In some optional embodiments, the first wave peak is located in the band range corresponding to the transmittance greater than or equal to 50% of the maximum blue light transmittance in the blue light transmittance spectrum of the display panel, the second wave peak is located in the band range corresponding to the transmittance greater than or equal to 50% of the maximum green light transmittance in the green light transmittance spectrum of the display panel, and the third wave peak is located in the band range corresponding to the transmittance greater than or equal to 50% of the maximum red light transmittance in the red light transmittance spectrum of the display panel, so that the spectrum of the backlight matches the transmission spectrum of the display panel.

[0033] In some optional embodiments, the display panel is a liquid crystal display panel, and the liquid crystal display panel includes a plurality of pixel units, each of which includes a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

[0034] According to another aspect of the present disclosure, a head-up display device is provided, comprising:

[0035] Optical output part,

[0036] In the above-mentioned image source of the head-up display device, the color gamut range of the virtual image formed by the image light output by the image source after passing through the optical path output part is greater than or equal to 45%.

[0037] According to another aspect of the present disclosure, a head-up display system is provided, comprising:

[0038] The above-mentioned head-up display device;

[0039] The reflective imaging unit is used to reflect the image light processed by the optical path output unit to the eye box area. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0041] Figure 1 An example of a light spectrum curve of a light source element based on a blue light chip exciting yellow phosphor is shown;

[0042] Figure 2A spectrum curve diagram of transmitted light of a display panel in an optional embodiment of the present disclosure is shown;

[0043] Figure 3 A schematic diagram of the light emission spectrum of a light source part in an optional embodiment of the present disclosure is shown;

[0044] Figure 4 The color gamut range of a virtual image formed by a head-up display device in an optional embodiment of the present disclosure is shown;

[0045] Figure 5 A schematic structural diagram of a head-up display device according to an optional embodiment of the present disclosure is shown;

[0046] Figure 6 A schematic structural diagram of a head-up display device according to another optional embodiment of the present disclosure is shown;

[0047] Figure 7 A schematic structural diagram of a head-up display device according to another optional embodiment of the present disclosure is shown;

[0048] Figure 8 A schematic structural diagram of a head-up display system according to an optional embodiment of the present disclosure is shown.

[0049] 10. Light source unit; 20. Display panel; 30. Light path output unit; 31. Amplifying element; 32. Plane reflector; 40. Reflective imaging unit; 50. Eye box area; 61. First wave peak; 62. Second wave peak; 63. Third wave peak; 70. Shell; 71. Opening. DETAILED DESCRIPTION

[0050] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0052] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not represent any order, quantity or importance, but are only used to distinguish different components. Similarly, "including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0053] As used herein, "parallel" and "perpendicular" include the described situation and the situation similar to the described situation, and the range of the similar situation is within the acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement being discussed and the error associated with the measurement of a specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, within 5°.

[0054] In head-up display devices, the color rendering ability of the backlight is relatively weak, especially in the long-wave band of visible light. For example, the backlight emitted by the light source contains a large amount of yellow-green light in the long-wave band of visible light (550nm-600nm band) without distinguishing the green light component from the red light component, resulting in lower purity of the green light component and the red light component, thereby resulting in lower color rendering.

[0055] In addition, heat dissipation of devices is one of the more difficult problems, and the temperature rise of the display panel (such as the LCD panel) in the head-up display device is mainly caused by the backlight and sunlight load. Due to the low transmittance of traditional display panels, most of the backlight incident on the display panel is absorbed and converted into heat energy, and the heat generated by the backflow of sunlight is superimposed, which limits the development of head-up display devices.

[0056] For example, the display panel 20 is a conventional liquid crystal display panel, that is, an RGB LCD display panel (Liquid Crystal Display), wherein the RGB LCD display panel includes a plurality of pixel units, each of which includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel. Figure 1The following is a graph showing the luminous spectrum of a light source element based on a blue light chip exciting yellow phosphor in an example. Figure 2 A spectral curve graph of transmitted light of a display panel in an embodiment is shown, wherein the R curve is a transmission spectrum curve when the red sub-pixels in the display panel are fully turned on, and the blue and green sub-pixels are fully turned off; the G curve is a transmission spectrum curve when the green sub-pixels are fully turned on, and the blue and red sub-pixels are fully turned off; the B curve is a transmission spectrum curve when the blue sub-pixels are fully turned on, and the red and green sub-pixels are fully turned off; and the W curve is a transmission spectrum curve when the blue, green and red sub-pixels are fully turned on.

[0057] It should be noted that fully turning on any R, G, B sub-pixel means that the grayscale value of the sub-pixel is the maximum value, that is, the transmittance of the sub-pixel reaches the maximum.

[0058] At present, the light source of the image source in the head-up display device mostly adopts the phosphor LED (Light-Emitting Diode) solution. The white light LED made by using the blue light chip to excite the yellow phosphor is one of the most common solutions. The spectrum curve formed by the white light LED made by the blue light chip to excite the yellow phosphor is as follows: Figure 1 As shown, due to its weak color rendering ability in the long-wave band of visible light (550nm to 650nm) and the mismatch with the red and green transmittance spectra of the display panel, the display panel has low transmittance and narrow color gamut, which in turn causes the display panel to absorb a large amount of backlight and convert it into heat energy, causing the head-up display device to temperature rise.

[0059] In order to solve the problem of low backlight color rendering of a head-up display device in the prior art, the present disclosure proposes an image source in a head-up display device, a head-up display device and a head-up display system.

[0060] like Figure 3 and Figure 5 As shown, the image source in the head-up display device includes a light source unit 10 and a display panel 20. The light source unit 10 is configured to emit backlight, and the backlight includes a first wave peak 61, a second wave peak 62 and a third wave peak 63, wherein the first wave peak 61, the second wave peak 62 and the third wave peak 63 are located in the bands corresponding to visible light of different colors; the display panel 20 is located on the light output side of the light source unit 10, and is configured to convert the backlight into image light and then output it.

[0061] The backlight in the present disclosure has a first wave crest 61, a second wave crest 62, and a third wave crest 63 located in different color bands, which can separate visible light of different colors, improve the purity of visible light of different colors, and thus improve the color rendering of the backlight. In addition, the spectrum of the backlight in the present disclosure matches the transmission spectrum of the display panel, which is conducive to more light in the backlight being able to pass through the display panel 20 and be converted into image light, thereby improving the transmittance of the backlight, so as to reduce the proportion of the display panel 20 converting the backlight into heat energy, thereby achieving the purpose of reducing temperature rise, and can also increase the color gamut range of the display panel, thereby increasing the color gamut range of the virtual image.

[0062] In some optional embodiments, the first peak 61, the second peak 62 and the third peak 63 are respectively located in the blue light band, the green light band and the red light band, so that the red light, green light and blue light can be separated, the purity of the red light, green light and blue light can be improved, and the color rendering of the backlight can be improved.

[0063] It should be noted that the matching of the backlight spectrum and the transmittance spectrum of the display panel 20 means that the first peak 61 is located in the band range corresponding to the blue light transmittance spectrum of the display panel 20 where the transmittance is greater than or equal to 50% of the maximum blue light transmittance, the second peak 62 is located in the band range corresponding to the green light transmittance spectrum of the display panel 20 where the transmittance is greater than or equal to 50% of the maximum green light transmittance, and the third peak 63 is located in the band range corresponding to the red light transmittance spectrum of the display panel 20 where the transmittance is greater than or equal to 50% of the maximum red light transmittance.

[0064] exist Figure 2In the specific embodiment shown, the B curve is the transmission spectrum curve when the blue sub-pixel is fully turned on and the red and green sub-pixels are fully turned off, that is, the blue light transmission spectrum curve. In the B curve, the wavelength range corresponding to 50% of the maximum blue light transmittance is 420nm to 530nm, and the first peak 61 in the present disclosure is between 435nm and 455nm, from which it can be seen that the first peak 61 matches the blue light transmission spectrum curve. The G curve is the transmission spectrum curve when the green sub-pixel is fully turned on and the blue and red sub-pixels are fully turned off, that is, the green light transmission spectrum curve. In the G curve, the wavelength range corresponding to 50% of the maximum green light transmittance is 480nm to 580nm, and the second peak 62 in the present disclosure is between 510nm and 550nm, from which it can be seen that the second peak 62 matches the green light transmission spectrum curve. The R curve is a transmission spectrum curve when the red sub-pixel in the display panel is fully turned on and the blue and green sub-pixels are fully turned off, that is, a red light transmission spectrum curve. In the R curve, the wavelength range corresponding to 50% of the maximum red light transmittance is 570nm to 750nm. The third peak 63 in the present disclosure is between 610nm and 660nm, so it can be seen that the third peak 63 matches the red light transmission spectrum curve. In summary, the spectrum of the backlight matches the transmission spectrum of the display panel 20.

[0065] For example, from Figure 2 It can be seen from FIG. 2 that the display panel 20 has a high transmittance for light with a wavelength of 420 nm to 700 nm. Figure 1 and Figure 2 It can be seen from the comparison that the transmittance of the display panel 20 in the range of 500nm to 700nm is higher, while Figure 1 The spectrum in the range of 500nm to 700nm is Figure 2 The transmission spectra of red and green light in the Figure 1 There is a certain amount of yellow-green light in the range of 500nm to 700nm. Figure 3 and Figure 1 In the comparison, it can be seen that the light intensity of the white light generated by the light source part in the embodiment of the present disclosure in the range of 500 to 700nm is significantly improved, and no yellow-green light is excited, which is conducive to separating the green light and the red light to improve the color rendering. Figure 2 and Figure 3 As shown, the backlight spectrum and the transmission spectrum of the display panel in the embodiment of the present disclosure match, which is beneficial to improving the transmittance of the display panel 20 to the white light generated by the light source part in the embodiment of the present disclosure, and improving the color gamut range of the display panel and the virtual image.

[0066] In some alternative embodiments, see Figure 3The peak wavelength of the first wave crest 61 is between 435nm and 455nm. The backlight has high energy in the range of 435nm to 455nm, and the display panel 20 has high transmittance to the light in this wavelength range, which is beneficial to improve the transmittance of the backlight on the display panel 20.

[0067] In some other optional embodiments, the peak wavelength of the first wave crest 61 is between 440nm and 450nm. The backlight has a higher energy in the range of 440nm to 450nm, and the display panel 20 has a higher transmittance to the light in this wavelength range, which is beneficial to improve the transmittance of the backlight on the display panel 20. In addition, the peak wavelength of the first wave crest 61 fluctuates in a smaller range, which can ensure the purity of the blue light and improve the color rendering of the backlight.

[0068] In some optional embodiments, the half-peak width of the spectrum corresponding to the first peak 61 is less than or equal to 40 nm. Limiting the half-peak width of the first peak 61 to a range less than 40 nm is conducive to ensuring the purity of the blue light.

[0069] In some alternative embodiments, see Figure 3 The peak wavelength of the second wave crest 62 is between 510nm and 550nm. The backlight has high energy in the range of 510nm to 550nm, and the display panel 20 has high transmittance to the light in this wavelength range, which is beneficial to improve the transmittance of the backlight on the display panel 20.

[0070] In some other optional embodiments, the peak wavelength of the second wave crest 62 is between 520nm and 540nm. The backlight has a higher energy in the range of 520nm to 540nm, and the display panel 20 has a higher transmittance to the light in this wavelength range, which is beneficial to improve the transmittance of the backlight on the display panel 20. In addition, the peak wavelength of the second wave crest 62 fluctuates in a smaller range, which can ensure the purity of the green light and improve the color rendering of the backlight.

[0071] In some optional embodiments, the half-peak width of the spectrum corresponding to the second wave peak 62 is less than or equal to 70 nm. This arrangement is conducive to ensuring the purity of green light.

[0072] In some alternative embodiments, see Figure 3 The peak wavelength of the third wave crest 63 is between 610nm and 660nm. The backlight has high energy in the range of 610nm to 660nm, and the display panel 20 has high transmittance to the light in this wavelength range, which is beneficial to improve the transmittance of the backlight on the display panel 20.

[0073] In some other optional embodiments, the peak wavelength of the third wave crest 63 is between 620nm and 650nm. The backlight has a higher energy in the range of 620nm to 650nm, and the display panel 20 has a higher transmittance to the light in this wavelength range, which is beneficial to improve the transmittance of the backlight on the display panel 20. In addition, the peak wavelength of the third wave crest 63 fluctuates in a smaller range, which can ensure the purity of the red light and improve the color rendering of the backlight.

[0074] In some optional embodiments, the half-peak width of the spectrum corresponding to the third wave peak 63 is less than or equal to 40 nm. This arrangement is conducive to ensuring the purity of the red light.

[0075] from Figure 3 It can be seen that the backlight in the present disclosure has almost no yellow-green light excited near 580nm-600nm, which is conducive to separating red light and green light, improving color rendering, and more closely matching the red and green light transmission spectra of the display panel 20, thereby improving the transmittance of the backlight, reducing the temperature rise of the display panel caused by the backlight, and improving the color gamut range and color expression of the head-up display device. Since the light source unit 10 in the present disclosure is used, the transmittance of the display panel 20 can be improved, so while maintaining the brightness of the virtual image unchanged, the backlight power consumption of the head-up display device can be reduced, and the temperature rise of the display panel caused by the backlight can be further reduced.

[0076] In some optional embodiments, the ratio of the irradiance integral value of the blue light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.3 and less than or equal to 0.5, wherein the irradiance integral value of the blue light component is the integral value of the spectral curve in the spectral curve diagram of the backlight within the wavelength range of 400nm to 500nm, and the irradiance integral value of the white light in the backlight is the integral value of the spectral curve in the spectral curve diagram of the backlight within the wavelength range of 400nm to 700nm.

[0077] In some optional embodiments, the ratio of the irradiance integral value of the green light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.25 and less than or equal to 0.45, wherein the irradiance integral value of the green light component is the integral value of the spectral curve in the spectral curve diagram of the backlight within the wavelength range of 500nm to 600nm, and the irradiance integral value of the white light in the backlight is the integral value of the spectral curve in the spectral curve diagram of the backlight within the wavelength range of 400nm to 700nm.

[0078] In some optional embodiments, the ratio of the irradiance integral value of the red light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.2 and less than or equal to 0.4; wherein, the irradiance integral value of the red light component is the integral value of the spectral curve in the spectral curve diagram of the backlight within the wavelength range of 600nm to 700nm, and the irradiance integral value of the white light in the backlight is the integral value of the spectral curve in the spectral curve diagram of the backlight within the wavelength range of 400nm to 700nm.

[0079] The ratio of the irradiance integral value of the blue light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.3 and less than or equal to 0.5, the ratio of the irradiance integral value of the green light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.25 and less than or equal to 0.45, and the ratio of the irradiance integral value of the red light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.2 and less than or equal to 0.4. This setting controls the light intensity in the wavelength range of 400nm to 500nm within a reasonable range, controls the light intensity in the wavelength range of 500nm to 600nm within a reasonable range, and controls the light intensity in the wavelength range of 600nm to 700nm within a reasonable range, thereby ensuring that when the backlight finally enters the human eye through the optical path output part of the head-up display device, the white light meets the visual requirements of the human eye.

[0080] It should be noted that the integral value of the spectral curve in the spectral curve diagram of the backlight within a certain wavelength range refers to the area enclosed by the spectral curve and the horizontal axis within the wavelength range. For example, the integral value of the spectral curve in the spectral curve diagram of the backlight within the wavelength range of 600nm to 700nm refers to the area enclosed by the spectral curve and the horizontal axis within the range of 600nm to 700nm.

[0081] Since the disclosure improves the light intensity of the red light and the green light in the backlight, thereby improving the matching degree of the red light and the green light in the backlight with the transmission spectrum of the display panel to the red light and the green light, the transmittance of the display panel 20 to the backlight is improved. In the embodiment of the disclosure, the transmittance of the display panel 20 to the backlight is greater than or equal to 5%. The increase in transmittance means that the absorption rate of the display panel 20 to the backlight is reduced, thereby achieving the purpose of reducing the temperature rise rate of the display panel 20, which is conducive to the stable operation of the display panel 20.

[0082] It should be noted that the transmittance of the display panel 20 to the backlight being greater than or equal to 5% refers to the maximum transmittance when all sub-pixels are fully turned on.

[0083] Due to the improvement of transmittance, the temperature of the display panel 20 can be reduced. That is to say, when the working power of the light source unit 10 is the same, the temperature of the display panel 20 in the present disclosure is lower and the service life of the display panel 20 is longer.

[0084] The backlight transmittance of the display panel 20 in the head-up display device disclosed in the present invention is 10% higher than that of the display panel 20 in the conventional head-up display device. In other words, the backlight transmittance of the display panel 20 to white light emitted by the yellow phosphor excited by the blue light chip is 10% higher.

[0085] In some optional embodiments, the abscissa of the white light in the backlight in the chromaticity diagram is greater than or equal to 0.25 and less than or equal to 0.30, and the ordinate is greater than or equal to 0.23 and less than or equal to 0.25. The abscissa and ordinate of the visible light in the backlight in the chromaticity diagram are limited to a reasonable range to ensure that when the backlight passes through the optical path output portion of the head-up display device and finally enters the human eye, the white light meets the visual requirements of the human eye.

[0086] Specifically, the chromaticity diagram may be the CIE (Commission Internationale de L'Eclairage, International Commission on Illumination) 1931xy chromaticity diagram. It should be noted that the CIE 1931xy chromaticity diagram refers to a two-dimensional chromaticity diagram with x and y as coordinates specified by the International Commission on Illumination in 1931, wherein red becomes increasingly pure along the positive direction of the x-axis, and green becomes increasingly pure along the positive direction of the y-axis.

[0087] In some optional embodiments, the electro-optical efficiency of the light source unit 10 is greater than 70 lm / W. For example, the electro-optical efficiency of the light source unit 10 is greater than 90 lm / W. This configuration enables the light source unit 10 to provide at least 70 lm of luminous flux per 1 W of electrical power, so that the light source unit 10 has a higher luminous efficiency, thereby reducing the generation of heat at the light source unit 10, thereby reducing the temperature rise of the image source and ensuring the stable operation of the image source.

[0088] In some optional embodiments, the light source unit 10 includes at least one light source element, each light source element includes a light emitting chip and a light emitting layer, the light emitting chip is configured to emit excitation light; the light emitting layer is located on the light emitting side of the light emitting chip, and the light emitting layer contains green phosphor and red phosphor. The green phosphor is configured to emit green light under the excitation of the excitation light, and the red phosphor is configured to emit red light under the excitation of the excitation light.

[0089] Optionally, the light-emitting chip is a blue light chip, and the emitted excitation light is blue light. The excitation light emitted by the light-emitting chip and the red light and green light emitted by the red phosphor and the green phosphor under the stimulation of the excitation light are finally mixed to form white light. The light source element in the present disclosure uses blue light emitted by a blue light chip to excite the red phosphor and the green phosphor to obtain white light, which improves the purity of the green light and the red light in the backlight, improves the color rendering of the backlight, and improves the matching degree of the transmission spectrum of the backlight and the display panel 20 for red light and green light, thereby improving the transmittance of the display panel 20 to the backlight.

[0090] Optionally, the green phosphor may be a silicate phosphor, and the red phosphor may be a fluoride phosphor.

[0091] In some optional embodiments, the peak wavelength of the excitation light is between 440nm and 450nm; the main peak wavelength of the green light is between 520nm and 540nm; and the main peak wavelength of the red light is between 620nm and 650nm. Limiting the peak wavelength of the excitation light, the main peak wavelength of the green light, and the main peak wavelength of the red light within the above range improves the color rendering of the backlight, and makes the backlight and the display panel 20 more closely matched to the transmission spectrum of white light, which is beneficial to improving the transmittance of the display panel 20 to the backlight.

[0092] In other optional embodiments, the light source element includes two light-emitting chips, both of which can be blue light chips, and the peak wavelengths of the excitation lights emitted by the two blue light chips are different. Of course, they can also be two light-emitting chips of different colors, and there is no specific limitation here.

[0093] In some optional embodiments, the ratio of the area of ​​the light-emitting layer to the area of ​​the light source unit 10 is greater than or equal to 1 and less than or equal to 1.5. If the ratio of the area of ​​the light-emitting layer to the area of ​​the light source unit 10 is less than 1, the light-emitting area is smaller and the light-emitting efficiency is lower. If the ratio of the area of ​​the light-emitting layer to the area of ​​the light source unit 10 is greater than 1.5, the light-emitting surface is too large and the divergence angle of the light is too large, which is not conducive to controlling the transmission direction of the backlight. Limiting the ratio of the area of ​​the light-emitting layer to the area of ​​the light source unit 10 within the above range is conducive to controlling the transmission of the backlight to the effective display area of ​​the display panel 20, so as to improve the utilization rate of the backlight.

[0094] Optionally, the area of ​​the light-emitting layer is less than 4 square millimeters, for example, the area of ​​the light-emitting layer is less than 2.25 square millimeters.

[0095] In some optional embodiments, the display panel 20 is a liquid crystal display panel, such as an RGB LCD display panel.

[0096] In some optional embodiments, the display panel 20 is a WRGB LCD display panel, that is, the display panel 20 includes a plurality of pixel units, each of which includes a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel. This arrangement further improves the transmittance of the liquid crystal display panel.

[0097] In another aspect, an embodiment of the present disclosure provides a head-up display device, see Figures 5 to 7As shown, it includes an optical path output unit 30 and the above-mentioned image source. The color gamut range of the virtual image formed by the image light output by the image source after passing through the optical path output unit 30 is greater than or equal to 45%. The virtual image formed by the above-mentioned image source has a larger color gamut range, which improves the color richness of the head-up display device and improves the user experience. For example, the color gamut range of the virtual image formed by the image light output by the image source after passing through the optical path output unit 30 is greater than or equal to 50% and less than or equal to 70%.

[0098] When the light source unit 10 emits Figure 1 When the white light is shown, the color coordinates of the virtual image RGB (Red Green Blue) formed by the image light output by the image source after passing through the optical path output unit 30 are R (0.5777, 0.3463), G (0.3306, 0.5674), and B (0.1638, 0.1364), respectively, and the corresponding NTSC (National Television Standards Committee) color gamut range is about 45.31%. Figure 3 When the white light is shown, the color coordinates of the virtual image RGB formed by the image light output by the image source after passing through the optical path output unit 30 are R (0.6179, 0.3237), G (0.2932, 0.6029), and B (0.1624, 0.1736), respectively, and the corresponding NTSC color gamut range is 55.59%, which is relatively 12 , yttrium aluminum garnet) powder white light LED increased by about 22.69%, as shown in the following Figure 4 As shown, Figure 4 Where N is the NTSC color gamut range corresponding to the virtual image formed by the head-up display device when the light source unit 10 adopts a blue light chip to excite the yellow phosphor to form white light; P is the NTSC color gamut range corresponding to the virtual image formed by the head-up display device when the light source unit 10 adopts a blue light chip to excite the red phosphor and the green phosphor to form white light; Q is the standard NTSC color gamut range.

[0099] It should be noted that the NTSC standard is a standard for measuring color gamut recognized by the display industry. The NTSC color gamut range is defined as the ratio of the area of ​​the triangle formed by the three primary colors to the area of ​​the triangle formed by the three primary colors of the standard NTSC under the CIE1931 xyz coordinates, where x+y+z=1 is satisfied in the CIE1931 xy chromaticity diagram, and the CIE1931 xy chromaticity diagram is usually used. The NTSC percentage of the color gamut triangle of the display is: NTSC (display) = S / 0.1582, where S is the area of ​​the triangle surrounded by the chromaticity coordinates of the three primary colors of the display, and 0.1582 is the area of ​​the triangle surrounded by the chromaticity coordinates of the three primary colors of the NTSC. If the coordinates of the three primary colors of R, G, and B of the display are (x1, y1), (x2, y2), and (x3, y3), respectively, then S = (x1y2-x1y3+x2y3-x2y1+x3y1-x3y2) / 2.

[0100] The head-up display device may further include a housing 70, wherein the image source and the light path output unit 30 are located in the housing 70, and the housing protects the image source and the light path output unit 30. The housing 70 may have an opening 71, so that the image light can be emitted from the opening 71.

[0101] In an alternative embodiment, see Figures 5 to 7 The optical path output unit 30 includes an amplifying element 31, which enables the head-up display device to have a longer imaging distance and a larger imaging size. For example, the imaging distance and the imaging size can be changed by changing the magnification of the amplifying element 31. The magnification can be changed by adjusting parameters such as the curvature of the amplifying element 31.

[0102] In some embodiments, the magnifying element 31 may be a curved reflector, see Figure 5 and Figure 6 For example, the image source is located within one focal length of the curved reflector. For example, the image source is located in the optical path from the focal plane of the curved reflector to the curved reflector. For example, the optical distance between the image source and the curved reflector is less than the focal length of the curved reflector.

[0103] Optionally, the curved reflector is a concave reflector, that is, a reflector whose reflective surface is a concave curved surface. In the case where the curved reflector is a concave reflector, if the optical distance between the image source and the concave reflector is less than the focal length of the concave reflector, the concave reflector forms an erected and enlarged virtual image based on the image output by the image source. For example, according to the imaging properties of the concave reflector, when the optical distance between the image source and the concave reflector is less than the focal length of the concave reflector (that is, the image source is located within one focal length of the concave reflector), the image distance of the concave reflector increases with the increase of the optical distance between the image source and the concave reflector, that is, the greater the optical distance between the image source and the concave reflector, the greater the distance between the user of the head-up display system including the head-up display device and the virtual image viewed by the user.

[0104] Optionally, the curved reflector is a free-form reflector, that is, the reflective surface is a free-form reflector, or the reflective surface does not have rotational symmetry, so as to improve the imaging quality of the display device.

[0105] In some other optional embodiments, the amplifying element 31 may be an optical waveguide or a holographic optical element.

[0106] It should be noted that the optical path output unit 30 of at least one embodiment of the present disclosure is not limited to only including the amplifying element 31. In some examples, the optical path output unit 30 also includes a plane reflector 32, through which the optical path of the image light propagation is adjusted, thereby reducing the volume of the head-up display device. Figure 6 and Figure 7 As shown, in this embodiment, the optical path output unit 30 further includes a plane reflector 32, which is disposed on the optical path between the image source and the magnifying element 31. The plane reflector 32 can change the imaging optical path of the image source, thereby changing the relative position between the image source and the magnifying element 31. When the magnifying element 31 is a curved reflector, the image source is located within one focal length of the curved reflector.

[0107] On the other hand, an embodiment of the present disclosure provides a head-up display system, referring to Figure 8 As shown, the head-up display device and the reflective imaging unit 40 are included. The reflective imaging unit 40 is used to receive the light corresponding to the virtual image emitted by the head-up display device and reflect it to the eye box area 50. The light corresponding to the virtual image output by the head-up display device is reflected by the reflective imaging unit 40 into the eye box area 50. When the user is located in the eye box area 50, the user can see the virtual image formed in the reflective imaging unit 40 away from the eye box area 50. The user can obtain the required information in the virtual image in front of the line of sight, such as driving speed, fuel consumption, etc. In addition, the virtual image can be a vertical picture or an inclined picture relative to the ground.

[0108] It should be noted that the eye box area 50 of the head-up display system refers to the area where the user's eyes are located and the image output by the head-up display system can be seen. The eye box area 50 has a certain size. The user's eyes deviate from the center of the eye box area by a certain distance, such as a certain distance in the up-down or left-right direction. As long as they are still in the eye box area, they can see the image output by the head-up display system.

[0109] In some optional embodiments, the reflective imaging unit 40 is a transflective element, that is, the reflective imaging unit 40 transmits a portion of light, such as the ambient light outside the cab, and reflects another portion of light, such as the light emitted by the head-up display device. The reflective imaging unit 40 may include a windshield, a skylight, a door window, etc.

[0110] exist Figure 8 In the head-up display system shown, the light emitted by the image source is reflected by the plane reflector 32 to the magnifying element 31, the magnifying element 31 reflects the light output by the plane reflector 32 to the reflective imaging unit 40, and the reflective imaging unit 40 reflects the light output by the magnifying element 31 to the eye box area 50.

[0111] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. An image source in a head-up display device, characterized in that: include: A light source unit, the light source unit is configured to emit backlight, the backlight includes a first wave peak, a second wave peak and a third wave peak, wherein the first wave peak, the second wave peak and the third wave peak are located in wave bands corresponding to visible light of different colors; The display panel is located at the light-emitting side of the light source unit and is configured to convert the backlight into image light for output.

2. The image source in the head-up display device according to claim 1, characterized in that: The first wave peak, the second wave peak and the third wave peak are respectively located in the blue light band, the green light band and the red light band.

3. The image source in the head-up display device according to claim 1, characterized in that: The backlight satisfies at least one of the following: The peak wavelength of the first wave peak is between 435nm and 455nm; The peak wavelength of the second wave peak is between 510nm and 550nm; The peak wavelength of the third wave peak is between 610nm and 660nm.

4. The image source in the head-up display device according to claim 3, characterized in that: The backlight satisfies at least one of the following: The peak wavelength of the first wave peak is between 440nm and 450nm; The peak wavelength of the second wave peak is between 520nm and 540nm; The peak wavelength of the third wave peak is between 620nm and 650nm.

5. The image source in the head-up display device according to claim 1, characterized in that: The backlight satisfies at least one of the following: The ratio of the irradiance integral value of the blue light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.3 and less than or equal to 0.5; The ratio of the irradiance integral value of the green light component in the backlight to the irradiance integral value of the white light in the backlight is greater than or equal to 0.25 and less than or equal to 0.45; A ratio of an irradiance integral value of a red light component in the backlight to an irradiance integral value of a white light component in the backlight is greater than or equal to 0.2 and less than or equal to 0.

4.

6. The image source in the head-up display device according to claim 1, characterized in that: The white light in the backlight has an abscissa greater than or equal to 0.25 and less than or equal to 0.30 in the chromaticity diagram, and a ordinate greater than or equal to 0.23 and less than or equal to 0.

25.

7. The image source in the head-up display device according to claim 1, characterized in that: The electro-optical efficiency of the light source is greater than 70 lm / W.

8. The image source in the head-up display device according to claim 1, characterized in that: The transmittance of the display panel to the backlight is greater than or equal to 5%.

9. The image source in the head-up display device according to any one of claims 1 to 8, characterized in that: The light source unit includes at least one light source element, each of which includes: A light-emitting chip, wherein the light-emitting chip is configured to emit excitation light; The light-emitting layer is located at the light-emitting side of the light-emitting chip, and contains green phosphor and red phosphor.

10. The image source in the head-up display device according to claim 9, characterized in that: A ratio of an area of ​​the light emitting layer to an area of ​​the light source portion is greater than or equal to 1 and less than or equal to 1.

5.

11. The image source in the head-up display device according to any one of claims 1 to 8, characterized in that: The backlight satisfies at least one of the following: The half-peak width of the spectrum corresponding to the first peak is less than or equal to 40 nm; The half-peak width of the spectrum corresponding to the second peak is less than or equal to 70 nm; The half-peak width of the spectrum corresponding to the third wave peak is less than or equal to 40 nm.

12. The image source in the head-up display device according to any one of claims 1 to 8, characterized in that: The first wave peak is located in the band range corresponding to the transmittance greater than or equal to 50% of the maximum blue light transmittance in the blue light transmittance spectrum of the display panel, the second wave peak is located in the band range corresponding to the transmittance greater than or equal to 50% of the maximum green light transmittance in the green light transmittance spectrum of the display panel, and the third wave peak is located in the band range corresponding to the transmittance greater than or equal to 50% of the maximum red light transmittance in the red light transmittance spectrum of the display panel, so that the spectrum of the backlight matches the transmittance spectrum of the display panel.

13. The image source in the head-up display device according to any one of claims 1 to 8, characterized in that: The display panel is a liquid crystal display panel, and the liquid crystal display panel includes a plurality of pixel units, each of which includes a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

14. A head-up display device, characterized in that: include: Optical output part, The image source in the head-up display device according to any one of claims 1 to 13, wherein the color gamut range of the virtual image formed by the image light output by the image source after passing through the optical path output portion is greater than or equal to 45%.

15. A head-up display system, characterized in that: include: The head-up display device according to claim 14; The reflective imaging unit is used to reflect the image light processed by the optical path output unit to the eye box area.

Images