Image display device

Abstract

To provide an image display device that can suppress color vision deterioration without changing a color reproduction range.SOLUTION: An image display device 100 comprises: an image display unit 10; a first light source 30 that has an emission peak of at least one emission spectrum in a wavelength range being more than or equal to 400 nm and less than 650 nm, and that forms an image on the image display unit 10; and a second light source 40 that has an emission peak of at least one emission spectrum in a wavelength range being more than or equal to 650 nm and less than or equal to 1000 nm, and in which full width at half maximum of the emission peak is more than or equal to 50 nm. First emitted light 31 emitted from the first light source 30 and second emitted light 41 emitted from the second light source 40 are irradiated toward the same object.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an image display device. [Background technology]

[0002] In recent years, technological developments have been progressing regarding image display devices such as televisions, personal computers, smartphones, etc. For example, Patent Document 1 discloses a display system including a first light-emitting element that emits display light used for image display, a second light-emitting element that irradiates a first special light within a wavelength range of 360 nm to 400 nm toward a user, and a control device that controls the irradiation of the first special light from the second light-emitting element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 124036 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of an embodiment of the present disclosure is to provide an image display device that can suppress a decrease in color vision without changing the color reproduction range. [Means for solving the problem]

[0005] An image display device according to an embodiment of the present disclosure includes an image display unit, a first light source having at least one emission peak of an emission spectrum in a wavelength range of 400 nm or more and less than 650 nm and forming an image on the image display unit, and a second light source having at least one emission peak of an emission spectrum in a wavelength range of 650 nm or more and 1000 nm or less and a full width at half maximum of the emission peak is 50 nm or more, and is configured such that a first emission light emitted from the first light source and a second emission light emitted from the second light source are irradiated toward the same target. Effect of the Invention

[0006] According to an embodiment of the present disclosure, it is possible to provide an image display device capable of suppressing the decline in color vision without changing the color reproduction range. [Brief description of the drawings]

[0007] [Figure 1] 1 is a plan view illustrating an example of a configuration of an image display device according to an embodiment. [Diagram 2] FIG. 2 is a perspective view illustrating an example of a first outgoing light emitted from a first light source and a second outgoing light emitted from a second light source of the image display device according to the embodiment. [Diagram 3] 1 is a perspective view showing an example of a positional relationship between light emitted from an image display device according to an embodiment and a user; [Figure 4A] FIG. 11 is a plan view diagrammatically illustrating a configuration of an image display device according to a first modified example. [Figure 4B] FIG. 13 is a plan view diagrammatically illustrating a configuration of an image display device according to a second modified example. [Figure 4C] FIG. 13 is a plan view diagrammatically illustrating a configuration of an image display device according to a third modified example. [Figure 5A] FIG. 13 is a plan view diagrammatically illustrating a configuration of an image display device according to a fourth modified example. [Figure 5B] FIG. 13 is a plan view diagrammatically illustrating a configuration of an image display device according to a fifth modified example. [Figure 6A] FIG. 13 is a plan view diagrammatically illustrating a configuration of an image display device according to a sixth modified example. [Figure 6B] FIG. 13 is an exploded perspective view showing an example of a configuration of an image display unit and a positional relationship between a first light source and a second light source in an image display device according to a sixth modified example. [Figure 7] FIG. 13 is a perspective view that illustrates a schematic configuration of an image display device according to a seventh modified example. [Figure 8A] FIG. 11 is a cross-sectional view showing a schematic example of the configuration of another embodiment of the first light source. [Figure 8B] FIG. 11 is a cross-sectional view showing a schematic example of the configuration of another embodiment of the second light source. [Figure 9A] 4 is a graph showing an emission spectrum of a first emitted light in Example 1. [Figure 9B] 4 is a graph showing an emission spectrum of a second emitted light in Example 1. [Figure 10A] 10 is a graph showing an emission spectrum of a first emitted light in Example 2. [Figure 10B] 10 is a graph showing an emission spectrum of a second emitted light in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The embodiments will be described below with reference to the drawings. However, the following embodiments are merely examples of image display devices for realizing the technical ideas of the present embodiments, and are not limited to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described in the embodiments are merely examples, and are not intended to limit the scope of the present invention. In order to avoid overly complicated drawings, some components may be omitted. The sizes and positional relationships of the components shown in each drawing may be exaggerated or simplified to clarify the explanation.

[0009] <<Embodiment>>

[0010] Fig. 1 is a plan view showing a schematic example of a configuration of an image display device according to an embodiment. Fig. 2 is a perspective view showing a schematic example of a first emitted light emitted from a first light source and a second emitted light emitted from a second light source of the image display device according to an embodiment. Fig. 3 is a perspective view showing a schematic example of a positional relationship between the emitted light emitted from the image display device according to an embodiment and a user. An image display device 100 according to this embodiment will be described with reference to FIGS. The image display device 100 according to this embodiment is a monitor of a personal computer.

[0011] The image display device 100 includes an image display section 10, a first light source 30 having at least one emission peak of an emission spectrum in a wavelength range of 400 nm or more and less than 650 nm and forming an image on the image display section 10, and a second light source 40 having at least one emission peak of an emission spectrum in a wavelength range of 650 nm or more and 1000 nm or less and having a full width at half maximum of 50 nm or more. In the image display device 100, a first outgoing light 31 emitted from the first light source 30 and a second outgoing light 41 emitted from the second light source 40 are irradiated toward the same target.

[0012] The image display device 100 includes an image display section 10, a bezel section 20, a first light source 30, and a second light source 40. Each component of the image display device 100 will be described below.

[0013] (Image display section) The image display unit 10 is a portion having a display screen 11 for displaying an image. Examples of the image display unit 10 include a liquid crystal display, an organic electroluminescence display, an LED display, and a projection display.

[0014] (Bezel part) The bezel section 20 is a portion formed in a frame shape around the image display section 10. The bezel section 20 is provided in a frame shape so as to support the image display section 10 and surround the periphery. As an example, the bezel section 20 is formed such that the vertical width of the lower frame below the image display section 10 is wider than the vertical width of the upper frame above the image display section 10. That is, the bezel section 20 is formed such that the area of ​​the lower frame is larger than the area of ​​the upper frame, and operation buttons such as a power button and a menu button (not shown) are provided. The image display section 10 and the bezel section 20 may have a known configuration as one used for a monitor of a general personal computer, and are not particularly limited.

[0015] (1st light source) The first light source 30 is a light source that emits light used for image display. A light-emitting element can be used as the first light source 30. The light-emitting element used for the first light source 30 may be any light-emitting element known for displaying an image on a display screen 11 such as a monitor of a personal computer, and is not particularly limited. As an example, the light-emitting element used for the first light source 30 may be an element having components such as color filters, liquid crystal, an alignment film, and electrodes for the three primary colors of R (red), G (green), and B (blue), and having a structure that emits the three primary colors as a whole. In addition, the first light source 30 may be a combination of a light-emitting element that emits red light, a light-emitting element that emits green light, and a light-emitting element that emits blue light. Examples of the light-emitting element include LEDs (Light Emitting Diodes) and laser diodes, and it is preferable to use LEDs from the viewpoint of energy saving and long life.

[0016] The image display device 100 is configured to be able to display various colors by arbitrarily controlling the color emission of each color using the first light source 30, and to display images and videos. The image display device 100 is also configured to be able to create pseudo-white light close to sunlight by predetermined pixel control. Specifically, the emission spectrum of the first light source 30 has at least one emission peak in the wavelength range of 400 nm or more and less than 650 nm. That is, the first light source 30 emits the first emitted light 31 having such an emission spectrum.

[0017] The first light source 30 is preferably provided in the image display unit 10. Here, providing the first light source 30 in the image display unit 10 means providing the first light source 30 behind the display screen 11, i.e., inside the monitor facing the display screen 11. For convenience, FIG. 1 illustrates a total of 18 first light sources 30, three in the vertical direction and six in the horizontal direction. However, the number, size, etc. of the first light sources 30 are not particularly limited and may be similar to those of a general personal computer monitor, etc.

[0018] (Second light source) The second light source 40 is a light source that emits light from deep red to near infrared. Specifically, the emission spectrum of the second light source 40 has at least one emission peak in the wavelength range of 650 nm to 1000 nm. Furthermore, the second light source 40 has a full width at half maximum (FWHM) of the emission peak of 50 nm or more. That is, the second light source 40 emits the second emitted light 41 having such an emission spectrum. The second emitted light 41 has the effect of suppressing the decrease in color vision as described below. Color vision is the function of discriminating and identifying the difference in wavelength of light in visible light as a difference in color.

[0019] Light having at least one emission peak of an emission spectrum in a wavelength range of 650 nm to 1000 nm and having a full width at half maximum of the emission peak of 50 nm or more (hereinafter, appropriately referred to as color vision restoration light or second emitted light) has the effect of increasing the sensitivity of the blue photoreceptor among the red photoreceptors, green photoreceptors, and blue photoreceptors of the retina of the eye. The color vision restoration light has the effect of activating mitochondria, which activates the blue photoreceptors. Therefore, the color vision restoration light acts on the eye of the user 80 and suppresses the deterioration of color vision. In addition, the color vision restoration light is unlikely to cause, for example, color shift or color unevenness due to the color vision restoration light when displaying an image. Therefore, the influence on the color reproduction range of the image is small. Therefore, by using the second light source 40, the image display device 100 can suppress the deterioration of color vision without significantly affecting the color reproduction range. Furthermore, the color vision restoration light puts less strain on the eyes than, for example, ultraviolet light or blue light, and is gentle on the eyes.

[0020] It is preferable that the second light source 40 has at least one emission peak of the emission spectrum in the wavelength range of 780 nm or more and 1000 nm or less. This can further suppress the deterioration of color vision without significantly affecting the color reproduction range. It is also preferable that the full width at half maximum of the emission peak of the second light source 40 is 100 nm or more. This can further suppress the deterioration of color vision without significantly affecting the color reproduction range. The upper limit of the full width at half maximum is not particularly limited, but is preferably, for example, 500 nm or less.

[0021] A light-emitting element can be used as the second light source 40. A combination of a plurality of light-emitting elements emitting different colors of light can be used as the second light source 40. Examples of the light-emitting element include an LED and a laser diode, and it is preferable to use an LED from the viewpoints of energy saving and long life.

[0022] The second light source 40 is preferably provided on the periphery of the image display unit 10. As an example, the second light source 40 is arranged by aligning a plurality of light emitting elements at a predetermined interval on the upper frame of the bezel unit 20 which is the periphery of the image display unit 10. With such a configuration, it is possible to further reduce the influence of the second emitted light 41 on the image display. Therefore, when an image is displayed, it is possible to further suppress the occurrence of, for example, color shift or color unevenness caused by the second emitted light 41. For example, five second light sources 40 are provided at equal intervals on the upper frame of the bezel unit 20, but the number may be any number and is not limited to five.

[0023] When viewing an image or video displayed on the image display device 100, the eye is often located in the direction approximately normal to the center of the display screen 11, so it is preferable that the second light source 40 is provided so that the second outgoing light 41 is irradiated in that direction. The distance from the display screen 11 of the image display device 100 to the eye is, for example, about 300 mm or more and 700 mm or less when the image display device 100 is a personal computer. Note that the distance from the display screen 11 of the image display device 100 to the eye is, for example, about 100 mm or more and 500 mm or less when the image display device is a smartphone, and is, for example, about 800 mm or more and 5000 mm or less when the image display device is a television. It is preferable that the image display device 100 is designed to design the outgoing direction, intensity, and irradiance of the second outgoing light 41 taking the distance into consideration.

[0024] The irradiance of the second outgoing light 41 is, for example, 1 mW / cm at the cornea. 2 More than 100mW / cm 2 The irradiance of the second emitted light 41 is preferably 1 mW / cm or less. 2 If the illumination level is more than 100 mW / cm, the deterioration of color vision can be suppressed. 2If it is equal to or less than this, the influence of the second outgoing light 41 on the color reproduction range will be smaller. The irradiance of the second outgoing light 41 may be adjusted as appropriate according to the usage environment of the image display device 100. The usage environment of the image display device 100 refers to, for example, whether the usage location is outdoors, indoors, at home, in an office, at school, etc., whether the usage time is day or night, whether the usage weather is fine, cloudy, rainy, etc.

[0025] In the image display device 100, the first outgoing light 31 emitted from the first light source 30 and the second outgoing light 41 emitted from the second light source 40 are irradiated toward the same target. This allows the image display device 100 to suppress deterioration of color vision without changing the color reproduction range. The first outgoing light 31 emitted from the first light source 30 and the second outgoing light 41 emitted from the second light source 40 being irradiated toward the same target means that both outgoing lights are irradiated toward the eye of the user 80 facing the display screen 11. Specifically, for example, when the first outgoing light 31 and the second outgoing light 41 spread radially or in a frustum shape toward the eye of the user 80 in the traveling direction, the central axis 31a of the first outgoing light 31 and the central axis 41a of the second outgoing light 41 are parallel. In addition, even if the central axis 31a of the first outgoing light 31 and the central axis 41a of the second outgoing light 41 are not parallel, at least a part of the first outgoing light 31 and the second outgoing light 41 overlap when they reach the eye of the user 80.

[0026] The first outgoing light 31 and the second outgoing light 41 being irradiated toward the same object includes the first outgoing light 31 and the second outgoing light 41 being irradiated in the same direction. The first outgoing light 31 and the second outgoing light 41 being irradiated in the same direction means, for example, that the central axis 31a of the first outgoing light 31 and the central axis 41a of the second outgoing light 41 are parallel to each other when the first outgoing light 31 and the second outgoing light 41 spread radially or in a frustum shape toward the traveling direction as described above. The light emitting surface of the first light source 30 and the light emitting surface of the second light source 40 are oriented in the same direction. The central axis of the outgoing light is the center of gravity of the area in which the light sources are aligned.

[0027] In the image display device 100, the ratio of the intensity of the first outgoing light 31 to the intensity of the second outgoing light 41 is preferably in the range of 100:10 to 100:80. That is, when the intensity of the first outgoing light 31 emitted from the first light source 30 is 100, the intensity of the second outgoing light 41 emitted from the second light source 40 is preferably 10 to 80. When the intensity of the first outgoing light 31 and the intensity of the second outgoing light 41 satisfy such a relationship, the difference between the CIE chromaticity of the first outgoing light 31 and the CIE chromaticity of the mixed light of the first outgoing light 31 and the second outgoing light 41 in the CIE chromaticity diagram of the CIE 1931 color space becomes small. Therefore, the influence on the color reproduction range by the second outgoing light 41 emitted from the second light source 40 becomes smaller. The intensity of the first outgoing light 31 and the intensity of the second outgoing light 41 are, for example, the emission spectrum intensity of the first outgoing light 31 and the emission spectrum intensity of the second outgoing light 41, respectively. The emission spectrum data of the first light source 30 and the second light source 40 is measured using, for example, a multichannel spectrometer "C10027-02" manufactured by Hamamatsu Photonics KK

[0028] From the viewpoint of reducing the influence on the color reproduction range, the ratio of the intensity of the first outgoing light 31 to the intensity of the second outgoing light 41 is more preferably 100:65 or less, and further preferably 100:45 or less.

[0029] The ratio of the intensity of the first outgoing light 31 to the intensity of the second outgoing light 41 may be adjusted as appropriate depending on the usage environment of the image display device 100. For example, the intensity of the second outgoing light 41 may be adjusted as appropriate in consideration of light in a predetermined wavelength range contained in sunlight or the like. The ratio between the intensity of the first outgoing light 31 and the intensity of the second outgoing light 41 may be set to an optimum ratio automatically or manually.

[0030] The image display device 100 may also include a sensor 50. This may automatically measure the distance and position from the display screen 11 to the eye, and automatically adjust the emission direction, intensity, irradiance, etc. of the second emission light 41 based on the measurement result. As the sensor 50, for example, a measuring device such as a CMOS sensor, a CCD sensor, or an infrared sensor may be used. Here, the sensor 50 is provided on the upper frame of the bezel portion 20, but may be provided at any position as long as it can perform its function.

[0031] Since the irradiance and dose (also called the amount of light energy) of the second emitted light 41 entering the eye vary depending on the distance from the display screen 11 to the eye, the eye can be irradiated with the irradiance set to a desired value by measuring the distance. It is also possible to automatically determine and measure whether the eye is facing the display screen 11, the number of blinks, and the time it takes. This makes it possible to accurately measure the irradiance and dose of the second emitted light 41 reaching the eye. Based on this result, the intensity, irradiance, and the like of the second emitted light 41 may be automatically adjusted. The image display device 100 may also notify the user 80 that the intensity or irradiance of the second emitted light 41 around the user 80 or near the eye is low or high by an image, a character string, or a voice. Then, the user 80 may perform a predetermined input operation to adjust the intensity or irradiance of the second emitted light 41.

[0032] As described above, the image display device 100 can suppress the decrease in color vision by including the second light source 40 that emits the second outgoing light 41. Moreover, the second outgoing light 41 is unlikely to cause color shift or color unevenness when displaying an image, and therefore has little effect on the color reproduction range of the image. Therefore, the image display device 100 can suppress the decrease in color vision without significantly affecting the color reproduction range. That is, the image display device 100 can suppress the decrease in color vision without changing the color reproduction range when displaying an image by the first light source 30. Moreover, the image display device 100 can further reduce the effect on the color reproduction range by setting the ratio between the intensity of the first outgoing light 31 and the intensity of the second outgoing light 41 to a predetermined range.

[0033] Although the image display device has been specifically described above by way of the embodiment of the invention, the gist of the present invention is not limited to these descriptions and should be broadly interpreted based on the claims. In addition, various changes and modifications based on these descriptions are also included in the gist of the present invention.

[0034] <<Variation>> The image display device of the modified example described below can also suppress the deterioration of color vision without significantly affecting the color reproduction range. Although the sensor is not shown in the image display device of the modified example, the sensor may be provided at any position, or the image display device may not have a sensor. 4A to 4C are plan views each showing a schematic configuration of an image display device according to a first modified example to a third modified example, respectively. 4A to 4C show an example in which the image display device is a monitor of a personal computer, and the first light source is not shown.

[0035] First Modified Example In the image display device 100A, the second light sources 40 are provided at equal intervals in the lower frame of the bezel portion 20 that surrounds the periphery of the image display unit 10. The number of second light sources 40 may be any number and is not limited to five. In general, in a personal computer monitor, the area of ​​the lower frame of the bezel portion 20 is larger than the area of ​​the upper frame of the bezel portion 20. Therefore, with such a configuration, the image display device 100A can easily provide the second light sources 40 in the bezel portion 20. Other details are the same as those of the image display device 100.

[0036] <Second Modification> In the image display device 100B, the second light sources 40 are provided at equal intervals on the upper and lower frames of the bezel portion 20 that surrounds the periphery of the image display portion 10. In FIG. 4B, five second light sources 40 are provided on the upper and lower frames of the bezel portion 20, respectively, but the number may be any number and is not limited to five. With this configuration, the image display device 100B can more easily irradiate the second emitted light 41 emitted from the second light source 40 toward the eyes of the user 80, regardless of whether the face of the user 80 faces upward or downward of the display screen 11. Other points are the same as those of the image display device 100.

[0037] <Third Modification> In the image display device 100C, the second light source 40 is provided in a frame shape on the periphery of the image display unit 10. In the image display device 100C, a plurality of second light sources 40 are continuously provided in a square shape along the periphery of the image display unit 10. With such a configuration, the image display device 100C can more easily irradiate the second emission light 41 emitted from the second light source 40 toward the eyes of the user 80, regardless of the direction in which the face of the user 80 faces the display screen 11. Other points are the same as those of the image display device 100.

[0038] 5A and 5B are plan views each showing a schematic configuration of an image display device according to a fourth modified example and a fifth modified example, respectively. 5A and 5B show an example in which the image display device is a smartphone, and the first light source is not shown.

[0039] <Fourth Modification> In the image display device 100D, one second light source 40 is provided in the center of the upper frame of the bezel portion 20 that surrounds the periphery of the image display unit 10. In this way, even if the image display device is a smartphone, by providing the second light source 40, it is possible to suppress a decrease in color vision without changing the color reproduction range. Other points are the same as those of the image display device 100, except that the image display device is a smartphone.

[0040] Fifth Modification In the image display device 100E, one second light source 40 is provided at the center of the upper frame of the bezel part 20 surrounding the periphery of the image display part 10, and five second light sources 40 are provided at equal intervals in the lower frame. The number of second light sources 40 may be any number and is not limited to five. With such a configuration, the image display device 100E can more easily irradiate the second emission light 41 emitted from the second light source 40 toward the eyes of the user 80, regardless of whether the face of the user 80 faces upward or downward of the display screen 11. Other details are the same as those of the image display device 100, except that the image display device is a smartphone.

[0041] Fig. 6A is a plan view showing a configuration of an image display device according to a sixth modified example, and Fig. 6B is an exploded perspective view showing an example of a configuration of an image display unit and a positional relationship between a first light source and a second light source in the image display device according to the sixth modified example. 6A and 6B show an example in which the image display device is a monitor of a personal computer, and the monitor is a liquid crystal backlight device.

[0042] <Sixth Modification> In the image display device 100F, the first light sources 30 and the second light sources 40 are provided on the periphery of the light guide plate 13 inside the image display unit 10. Specifically, the first light sources 30 and the second light sources 40 are provided alternately in the left-right direction on the lower frame of the bezel unit 20 surrounding the periphery of the image display unit 10. Here, the image display device 100F is provided with eight first light sources 30 and nine second light sources 40, but the number is not limited to this. The first light source 30 and the second light source 40 are provided inside the bezel portion 20. According to such a configuration, in the image display device 100F, the first light source 30 and the second light source 40 are fixed in parallel to the periphery of the light guide plate 13, as described later, so that the light emitted from the first light source 30 and the second light source 40 can be easily guided to the light guide plate 13. Furthermore, the first light source 30 and the second light source 40 may be provided in the upper frame of the bezel portion 20, or may be provided in both the upper frame and the lower frame.

[0043] As shown in FIG. 6B, the image display unit 10 of the image display device 100F has, for example, a reflecting sheet 12, a light guide plate 13, a lower diffusion sheet 14, a prism sheet 15, and an upper diffusion sheet 16. These members are fixed to the rear cover 17 in this order. The first light source 30 and the second light source 40 are fixed in parallel to the periphery of the light guide plate 13 so as to be located in the lower frame of the bezel part 20 when the bezel part 20 surrounding the periphery of the image display unit 10 is provided. The image display device 100F converts the first outgoing light 31 emitted from the first light source 30 and the second outgoing light 41 emitted from the second light source 40 into planar first outgoing light 31 and second outgoing light 41 using the reflecting sheet 12, the light guide plate 13, the lower diffusion sheet 14, the prism sheet 15, and the upper diffusion sheet 16, and emits them from the image display unit 10. Furthermore, a polarizing plate, a liquid crystal layer, a color filter, etc. may be further provided on the upper diffusion sheet 16 .

[0044] FIG. 7 is a perspective view illustrating a schematic configuration of an image display device according to a seventh modified example. 7 shows an example in which the image display device is a monitor of a personal computer, and the first light source is not shown.

[0045] <Seventh Modification> In the image display device 100G, the second light source 40 is provided outside the bezel portion 20 surrounding the periphery of the image display unit 10. Specifically, in the image display device 100G, the second light source 40 is attached as an accessory part 45 to the upper side of the right frame of the bezel portion 20, i.e., the upper right part of the monitor, in a detachable form. The position where the second light source 40 is provided may be adjusted to any position as appropriate. With such a configuration, the image display device 100G can place the second light source 40 at any position of the user 80. In addition, it becomes easy to adjust the emission direction of the second emission light 41 emitted from the second light source 40. Furthermore, for example, the second light source 40 can be removed as necessary.

[0046] For example, the first light source and the second light source may have other forms. Fig. 8A is a cross-sectional view showing an example of the configuration of another embodiment of the first light source, and Fig. 8B is a cross-sectional view showing an example of the configuration of another embodiment of the second light source.

[0047] The first light source 30A shown in FIG. 8A includes a light emitting element 32 and a wavelength conversion member 33 provided on the light emitting surface of the light emitting element 32. That is, the first light source 30A may be configured to have at least one emission peak of the emission spectrum in a wavelength range of 400 nm or more and less than 650 nm by combining the light emitting element 32 and the wavelength conversion member 33. The wavelength conversion member 33 may include a phosphor as a wavelength conversion material. Examples of the phosphor used in the wavelength conversion member 33 include yttrium aluminum garnet activated with cerium, lutetium aluminum garnet activated with cerium, terbium aluminum garnet activated with cerium, nitrogen-containing calcium aluminosilicate activated with any one or two of europium and chromium, sialon activated with europium, silicate activated with europium, potassium fluorosilicate activated with manganese, and nitride phosphor activated with europium.

[0048] The second light source 40A shown in FIG. 8B includes a light emitting element 42, a wavelength conversion member 43 provided on the light emitting surface of the light emitting element 42, and an upper surface of the wavelength conversion member 43 (the side opposite to the light emitting surface of the light emitting element 42). of and a dielectric multilayer film 44 provided on the second output light 41 (the first output light 41 face). That is, the second light source 40A may have at least one emission peak of an emission spectrum in a wavelength range of 650 nm or more and 1000 nm or less, and the full width at half maximum of the emission peak may be 50 nm or more, by using the light emitting element 42, the wavelength converting member 43, and the dielectric multilayer film 44. By providing the wavelength converting member 43 and the dielectric multilayer film 44, the second light source 40A can easily control the emission spectrum of the second output light 41.

[0049] The wavelength conversion member 43 may include a phosphor as a wavelength conversion material. Examples of the phosphor used in the wavelength conversion member 43 include Ga2O3:Cr, La3Al3Ga2GeO14 By using such a phosphor, the full width at half maximum of the emission peak can be easily broadened.

[0050] The dielectric multilayer film 44 is a type of distributed Bragg reflector film (DBR (Distributed Bragg Reflector)). The dielectric multilayer film 44 is a film in which a set of dielectrics, each consisting of a low refractive index layer and a high refractive index layer, is laminated over multiple sets, and selectively reflects light of a predetermined wavelength. Specifically, it is a film in which two or more types of films with different refractive indexes are alternately laminated with a thickness of wavelength / 4n (n is the refractive index), and can reflect light of a predetermined wavelength with high efficiency. An example of a low refractive index material is SiO2, and an example of a high refractive index material is Nb2O5, TiO2, ZrO2, Ta2O5, etc. An example of the dielectric multilayer film is one in which layers made of SiO2 and layers made of Nb2O5 are alternately laminated.

[0051] Alternatively, the second light source may not use a dielectric multilayer film and may instead include a wavelength conversion member on the light emitting surface of the light emitting element. With this configuration, the second light source may have at least one emission peak of the emission spectrum in a wavelength range of 650 nm to 1000 nm, and the full width at half maximum of the emission peak may be 50 nm or more. Even with this configuration, the second light source makes it easier to control the emission spectrum of the second emitted light. Furthermore, the number, size, arrangement position, etc. of the second light sources may be appropriately adjusted depending on the type, use, size, etc. of the image display device. EXAMPLES

[0052] Examples will be described below. Fig. 9A is a graph showing an emission spectrum of a first emitted light in Example 1. Fig. 9B is a graph showing an emission spectrum of a second emitted light in Example 1. Fig. 10A is a graph showing an emission spectrum of a first emitted light in Example 2. Fig. 10B is a graph showing an emission spectrum of a second emitted light in Example 2.

[0053] In this embodiment, the emission spectrum of the first emission light emitted from the first light source and the emission spectrum of the second emission light emitted from the second light source were measured, and the CIE chromaticity in the chromaticity diagram of the CIE 1931 color space was measured by simulation.

[0054] [Example 1] FIG. 9A shows the emission spectrum of the first emitted light from the first light source when the LED and phosphor shown in Table 1 are used, and FIG. 9B shows the emission spectrum of the second emitted light from the second light source when the LED and phosphor shown in Table 1 are used. The LED of the second light source is assumed to have a DBR film on the emission surface that has a reflectance of 100% in the wavelength range of 390 nm or more and 560 nm or less, formed by stacking multiple layers of SiO2 and Nb2O5. In addition, the CIE chromaticity of the first emitted light and the second emitted light was measured when the LED and phosphor shown in Table 1 were used. The results are shown in Table 2. In Table 2, samples with deviations of less than 0.01 in the CIE chromaticity x and CIE chromaticity y values ​​compared to No. 11, which does not emit the second outgoing light, were deemed to be less affected by the second outgoing light in the color reproduction range.

[0055] [Table 1]

[0056] [Table 2]

[0057] As shown in Table 2, the deviations in the CIE chromaticity x and CIE chromaticity y values ​​of No. 3 to No. 10 were less than 0.01 compared to No. 11. On the other hand, the deviations in the CIE chromaticity x value of No. 1 and No. 2 were 0.01 or more compared to No. 11.

[0058] [Example 2] FIG. 10A shows the emission spectrum of the first emitted light from the first light source when the LED and phosphor shown in Table 3 are used, and FIG. 10B shows the emission spectrum of the second emitted light from the second light source when the LED and phosphor shown in Table 3 are used. Furthermore, the CIE chromaticity of the first emitted light and the second emitted light was measured when the LED and phosphor shown in Table 3 were used. The results are shown in Table 4. In Table 4, "-" indicates that the CIE chromaticity was not measured. In Table 4, samples with deviations of less than 0.01 in the CIE chromaticity x and CIE chromaticity y values ​​compared to No. 22, which does not emit the second outgoing light, were deemed to be less affected by the second outgoing light in the color reproduction range.

[0059] [Table 3]

[0060] [Table 4]

[0061] As shown in Table 4, the deviations of the CIE chromaticity x and CIE chromaticity y values ​​of No. 12 and No. 20 were 0.01 or more compared to No. 11. The deviations of the CIE chromaticity y value of No. 21 were 0.01 or more compared to No. 22. Since the deviations of the CIE chromaticity x value were 0.01 or more when the intensity of the second emitted light was 20 or 100 when the intensity of the first emitted light was 100, it was determined that the deviations of the CIE chromaticity x value were also 0.01 or more for samples with the intensity of the second emitted light of 30 to 90 when the intensity of the first emitted light was 100. Therefore, the CIE chromaticity was not measured for No. 13 to No. 19.

[0062] From the above results, it can be seen that in a second light source having at least one emission peak of an emission spectrum in the wavelength range of 650 nm or more and 1000 nm or less, and the full width at half maximum of the emission peak is 50 nm or more, when the intensity of the first emitted light is taken as 100, when the intensity of the second emitted light is 10 or more and 80 or less, the effect of the second emitted light on the color reproduction range is less, which is preferable. [Industrial Applicability]

[0063] The image display device according to the embodiment of the present disclosure can be used as a monitor for a personal computer, a smartphone, a television, a game machine, and other image display devices (for example, displays and monitors used for various purposes). [Explanation of symbols]

[0064] 10 Image display section 11 Display screen 12 Reflective sheet 13 Light guide plate 14 Lower diffusion sheet 15 Prism sheet 16 Upper diffusion sheet 17 Rear cover 20 Bezel 30, 30A 1st light source 31 First exit light 31a Central axis of the first emitted light 32 Light emitting element 33 Wavelength conversion materials 40, 40A 2nd light source 41 Second exit light 41a Central axis of second emitted light 42 Light emitting element 43 Wavelength conversion material 44 Dielectric multilayer film 45 Accessories 50 Sensors 80 User 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G Image display device

Claims

1. An image display unit; a first light source having at least one emission peak of an emission spectrum in a wavelength range of 400 nm or more and less than 650 nm and forming an image on the image display unit; A second light source having at least one emission peak of an emission spectrum in a wavelength range of 650 nm to 1000 nm, the full width at half maximum of the emission peak being 50 nm or more; A first emitted light emitted from the first light source and a second emitted light emitted from the second light source are irradiated toward a same target, the first light source is provided on the image display unit, and the second light source is provided on a periphery of the image display unit, The image display device, wherein the ratio of the intensity of the first emitted light to the intensity of the second emitted light is in the range of 100:10 to 100:

80.

2. An image display unit; a first light source having at least one emission peak of an emission spectrum in a wavelength range of 400 nm or more and less than 650 nm and forming an image on the image display unit; A second light source having at least one emission peak of an emission spectrum in a wavelength range of 650 nm to 1000 nm, the full width at half maximum of the emission peak being 50 nm or more; A first emitted light emitted from the first light source and a second emitted light emitted from the second light source are irradiated toward a same target, the first light source and the second light source are provided on a periphery of the image display unit, The image display device, wherein the ratio of the intensity of the first emitted light to the intensity of the second emitted light is in the range of 100:10 to 100:

80.

3. An image display unit; a first light source having at least one emission peak of an emission spectrum in a wavelength range of 400 nm or more and less than 650 nm and forming an image on the image display unit; A second light source having at least one emission peak of an emission spectrum in a wavelength range of 650 nm to 1000 nm, the full width at half maximum of the emission peak being 50 nm or more; A first emitted light emitted from the first light source and a second emitted light emitted from the second light source are irradiated toward a same target, the second light source has at least one emission peak of an emission spectrum in a wavelength range of 780 nm or more and 1000 nm or less; The image display device, wherein the ratio of the intensity of the first emitted light to the intensity of the second emitted light is in the range of 100:10 to 100:

80.

4. An image display unit; a first light source having at least one emission peak of an emission spectrum in a wavelength range of 400 nm or more and less than 650 nm and forming an image on the image display unit; A second light source having at least one emission peak of an emission spectrum in a wavelength range of 650 nm to 1000 nm, the full width at half maximum of the emission peak being 50 nm or more; A first emitted light emitted from the first light source and a second emitted light emitted from the second light source are irradiated toward a same target, a ratio of an intensity of the first emitted light to an intensity of the second emitted light is in a range of 100:10 to 100:80; The second light source is an image display device comprising: a light-emitting element; a wavelength conversion member provided on a light-emitting surface of the light-emitting element; and a dielectric multilayer film provided on a surface of the wavelength conversion member opposite the light-emitting surface of the light-emitting element.

5. 5. The image display device according to claim 3, wherein the first light source is provided on the image display section, and the second light source is provided on a periphery of the image display section.

6. The image display device according to claim 1 , wherein the second light source is provided in a frame shape on a periphery of the image display unit.

7. The image display device according to claim 3 , wherein the first light source and the second light source are provided on a periphery of the image display unit.

8. 8. The image display device according to claim 1, except when claim 3 is recited, wherein the second light source has at least one emission peak of an emission spectrum in a wavelength range of 780 nm to 1000 nm.

9. 9. The image display device according to claim 1, wherein the full width at half maximum of the emission peak of the second light source is 100 nm or more.

10. The image display device according to claim 1 , except where claim 4 is recited, wherein the first light source and the second light source are LEDs.

11. 11. The image display device according to claim 1, wherein the image display section is any one of a liquid crystal display, an organic electroluminescence display, an LED display, and a projection display.

12. The first emitted light emitted from the first light source and the second emitted light emitted from the second light source are irradiated toward an eye of a user facing the image display unit, The irradiance of the second emitted light is 1 mW / cm at the cornea of ​​the user. ２ 100mW / cm or more ２ 12. The image display device according to claim 1, wherein:

13. The first emitted light emitted from the first light source and the second emitted light emitted from the second light source are irradiated toward an eye of a user facing the image display unit, Further comprising a sensor for measuring a distance and a position from the image display unit to the eye of the user, The image display device according to claim 1 , wherein an emission direction, intensity, or irradiance of the second emission light is adjustable based on a measurement result by the sensor.

Images