Indication device

Abstract

To provide a display device that can accurately detect the degree of degradation of a liquid crystal panel. [Solution] A display device comprising: an outer casing; a liquid crystal panel provided inside the outer casing that emits second light including light in a longer wavelength range than the first wavelength range when first light including light in a first wavelength range is incident on it; a light detection unit that detects the second light and a third light incident from outside the outer casing; a first light guide unit that guides the third light to the light detection unit; and a control unit that corrects the detected value of the second light detected by the light detection unit based on the detected value of the third light detected by the light detection unit.

Description

Technical Field

[0001] The present invention relates to a display device.

Background Art

[0002] In a projection-type display device, light emitted from a light source is irradiated onto a transmissive liquid crystal panel or a reflective liquid crystal panel, and the transmitted light or reflected light modulated by the liquid crystal panel is projected onto a screen. In such a display device, since the liquid crystal panel is irradiated with high-intensity light from the light source, the liquid crystal panel may deteriorate.

[0003] For example, Patent Document 1 describes a liquid crystal display device that detects the chromaticity or illuminance of a light beam emitted from a liquid crystal panel by an optical sensor, and controls a cooling means by determining the image quality state of an optical image based on the detection result.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0007] [Figure 1] A schematic diagram showing the display device according to this embodiment. [Figure 2] A schematic diagram showing the display device according to this embodiment. [Figure 3] A schematic diagram showing the display device according to this embodiment. [Figure 4] A schematic plan view showing the liquid crystal panel of the display device according to this embodiment. [Figure 5] A schematic cross-sectional view showing the liquid crystal panel of the display device according to this embodiment. [Figure 6] A schematic cross-sectional view showing the display device according to this embodiment. [Figure 7] A schematic side view showing the display device according to this embodiment. [Figure 8] A graph illustrating the time-dependent change in photoluminescence when a liquid crystal layer is irradiated with blue light. [Figure 9] A graph illustrating the change in photoluminescence over time during accelerated degradation testing of liquid crystal panels. [Figure 10] A graph illustrating the change in photoluminescence over time during accelerated degradation testing of liquid crystal panels. [Figure 11] A graph illustrating the electro-optical properties of a liquid crystal panel. [Figure 12] A flowchart illustrating the operation of the display device according to this embodiment. [Figure 13] A schematic cross-sectional view showing a display device according to the first modified example of this embodiment. [Figure 14] A schematic side view showing a display device according to a first modified example of this embodiment. [Figure 15] A schematic diagram showing a display device according to a second modified example of this embodiment. [Figure 16] Side view schematically showing a display device according to a second modification of the present embodiment.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0009] 1. Display Device 1.1. Overall Configuration First, the display device 100 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a diagram schematically showing the display device 100 according to the present embodiment.

[0010] As shown in FIG. 1, the display device 100 has, for example, a light source device 10, dichroic mirrors 20 and 22, reflection mirrors 24, 26, and 28, relay lenses 30, 32, 34, 36, and 38, light modulation devices 40R, 40G, and 40B, a cross-dichroic prism 50 as a light combining device, a projection optical system 60, a light detection device 70, a housing for optical components 80, a control unit 90, and a storage unit 95. The display device 100 is, for example, a projector of the 3LCD (Liquid Crystal Display) type.

[0011] Although not shown in the drawings, the light source device 10 has, for example, a light source and an optical system. The light source is, for example, an array light source having a semiconductor laser, or a lamp unit composed of a white light source such as an ultra-high pressure mercury lamp or a halogen lamp. Light from the light source is incident on the optical system. The optical system is, for example, an integrator lens that enhances the uniformity of the light from the light source.

[0012] The dichroic mirror 20 transmits red light (R) and reflects green light (G) and blue light (B) from the light emitted from the light source device 10. The dichroic mirror 22 reflects the green light (G) reflected by the dichroic mirror 20 and transmits blue light (B).

[0013] Red light (R) transmitted through the dichroic mirror 20 is reflected by the reflective mirror 24 and then incident on the optical modulator 40R via the relay lens 30. Green light (G) reflected by the dichroic mirror 22 is incident on the optical modulator 40G via the relay lens 32. Blue light (B) transmitted through the dichroic mirror 22 is incident on the optical modulator 40B via the relay lens 34, reflective mirror 26, relay lens 36, reflective mirror 28, and relay lens 38.

[0014] The optical modulators 40R, 40G, and 40B are positioned opposite each other to the light incidence surface of the cross dichroic prism 50 for each color of light. The optical modulators 40R, 40G, and 40B modulate the incident color of light based on video information (video signal).

[0015] The colored light modulated by the optical modulators 40R, 40G, and 40B is emitted toward the cross dichroic prism 50, respectively. In the illustrated example, each of the optical modulators 40R, 40G, and 40B is positioned between the first polarizing element 41a and the second polarizing element 41b. Details of the optical modulators 40R, 40G, and 40B will be described later.

[0016] In the cross dichroic prism 50, four right-angle prisms are bonded together, and on its inner surface, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape. These dielectric multilayer films combine the three colors of light to create light that represents a color image. The light combined in the cross dichroic prism 50 is emitted toward the projection optical system 60.

[0017] The projection optical system 60 projects the incident combined light onto the screen 2. On the screen 2, the image is displayed enlarged. In the illustrated example, the projection optical system 60 is composed of, for example, a biconvex lens 62, a biconcave lens 64, and a biconvex lens 66.

[0018] The light detection device 70 is located to the side of the light modulator 40B. The light detection device 70 detects light emitted from the side of the light modulator 40B when blue light is incident on the liquid crystal panel of the light modulator 40B. Details of the light detection device 70 will be described later.

[0019] The optical component housing 80 houses, for example, a light source device 10, dichroic mirrors 20, 22, reflective mirrors 24, 26, 28, relay lenses 30, 32, 34, 36, 38, optical modulators 40R, 40G, 40B, cross dichroic prism 50, and projection optical system 60. The material of the optical component housing 80 and the outer housing 81 is, for example, metal, resin, etc.

[0020] The control unit 90 includes, for example, a light source control unit 91, a detection signal processing unit 92, and a central control unit 93.

[0021] The light source control unit 91 is electrically connected to the light source of the light source device 10. The light source control unit 91 controls the light source of the light source device 10. The light source control unit 91 generates a drive signal based on a signal from the central control unit 93 and transmits the generated drive signal to the light source of the light source device 10.

[0022] The detection signal processing unit 92 is electrically connected to the photodetector 70. The detection signal processing unit 92 acquires a detection signal from the photodetector 70 and transmits the acquired detection signal to the central control unit 93.

[0023] The central control unit 93 controls the light source of the light source device 10 via the light source control unit 91. Furthermore, the central control unit 93 acquires a detection signal from the photodetector 70 via the detection signal processing unit 92. The light source control unit 91, the detection signal processing unit 92, and the central control unit 93 are configured, for example, by including an integrated circuit (IC).

[0024] The central control unit 93 includes a degradation determination unit 94. The degradation determination unit 94 determines the degree of degradation of the liquid crystal panel of the optical modulation device 40B based on the acquired detection signal. The specific processing of the degradation determination unit 94 will be described later.

[0025] The memory unit 95 stores programs and data for the control unit 90 to perform various calculation and control processes. The memory unit 95 is composed of, for example, RAM (Random Access Memory) and ROM (Read Only Memory).

[0026] In addition to projectors, the display device 100 can be applied to various electronic devices such as LCD panels for photocuring 3D printers, EVFs (Electrical View Finders), mobile mini projectors, head-up displays, smartphones, mobile phones, mobile computers, digital cameras, digital video cameras, displays, in-vehicle equipment, audio equipment, exposure equipment, and lighting equipment.

[0027] 1.2. Optical Modulator Figures 2 and 3 are schematic diagrams of the display device 100. Figure 2 shows the connector 164 connected to the connection part 82 fixed to the outer casing 81. The outer casing 81 houses the optical component housing 80, the light source device 10, and the control unit 90. Figure 3 shows the light-shielding cap 170 connected to the connection part 82. In Figure 2, the X, Y, and Z axes are shown as three mutually orthogonal axes.

[0028] In the display device 100, for example, before using the display device 100 as a projector, the connector 164 is connected to the connection part 82 as shown in Figure 2 to calibrate the light detection device 70. After calibrating the light detection device 70, the connector 164 is removed from the connection part 82, and the light-shielding cap 170 is connected to the connection part 82 as shown in Figure 3, and the display device 100 is used as a projector.

[0029] As shown in Figures 2 and 3, the optical modulation device 40B includes a liquid crystal panel 42, a COF (Chip On Film) 44, and a holder 46. The liquid crystal panel 42 modulates the incident light based on image information. The liquid crystal panel 42 is an actively driven liquid crystal panel having a thin-film transistor (TFT) as a transistor for each pixel.

[0030] Figure 4 is a schematic plan view of the liquid crystal panel 42. Figure 5 is a schematic cross-sectional view of the liquid crystal panel 42 along the VV' line in Figure 4.

[0031] As shown in Figures 4 and 5, the liquid crystal panel 42 includes, for example, an element substrate 110, a sealing material 120, a liquid crystal layer 130, and a counter substrate 140.

[0032] As shown in Figure 4, the element substrate 110 is larger than the opposing substrate 140 when viewed from the normal direction of the element substrate 110 of the optical modulator 40B (hereinafter also simply referred to as "viewed from the normal direction"). The planar shape of the element substrate 110 is, for example, a rectangle. The normal direction is the direction in which the normal N of the surface of the first support substrate 112 of the element substrate 110 on the liquid crystal layer 130 side extends. The normal direction is, for example, the stacking direction of the element substrate 110 and the liquid crystal layer 130. In the illustrated example, the normal direction is the Z-axis direction.

[0033] The sealing material 120 joins the element substrate 110 and the opposing substrate 140. The sealing material 120 is provided along the outer edge of the opposing substrate 140. When viewed from the normal direction, the sealing material 120 surrounds the liquid crystal layer 130. The sealing material 120 is an adhesive such as a thermosetting, photocuring, or electron beam curing epoxy resin. Inside the sealing material 120, a display area E is provided, which includes a plurality of pixels P arranged in a matrix. The display area E is surrounded by a peripheral area F. In the peripheral area F, a trim portion 142 is provided between the sealing material 120 and the display area E, surrounding the display area E. The material of the trim portion 142 is, for example, a light-shielding metal or metal oxide.

[0034] The element substrate 110 includes, for example, an external connection terminal 101, a data line drive circuit 102, a test circuit 103, a scan line drive circuit 104, a first wiring 105, and a second wiring 106.

[0035] Multiple external connection terminals 101 are provided. In the illustrated example, the multiple external connection terminals 101 are arranged in the X-axis direction. The data line drive circuit 102 is provided between the first side, which is aligned with the multiple external connection terminals 101, and the sealing material 120. The inspection circuit 103 is provided between the sealing material 120, which is aligned with the second side opposite the first side, and the display area E. The scan line drive circuit 104 is provided between the sealing material 120, which is aligned with the third and fourth sides, which are perpendicular to the first side and opposite each other, and the display area E. Although not shown in the illustration, the inspection circuit 103 may also be provided between the sealing material 120 aligned with the data line drive circuit 102 and the display area E.

[0036] The first wiring 105 is located between the sealing material 120 along the second side and the test circuit 103. The first wiring 105 is connected to two scan line drive circuits 104. The second wiring 106 is connected to the data line drive circuit 102 and the scan line drive circuit 104. The second wiring 106 is electrically connected to a plurality of external connection terminals 101.

[0037] As shown in Figure 5, the element substrate 110 includes, for example, a first support substrate 112, a pixel electrode 114, a TFT 116, and a first alignment layer 118.

[0038] The first support substrate 112 supports the pixel electrode 114, the TFT 116, and the first alignment layer 118. The first support substrate 112 is, for example, a glass substrate or a quartz substrate. The first support substrate 112 transmits light emitted from the light source.

[0039] The pixel electrodes 114 and TFT 116 are provided on the liquid crystal layer 130 side of the first support substrate 112. Each pixel electrode 114 and TFT 116 is provided for each pixel P. Multiple pixel electrodes 114 and TFT 116 are provided to correspond to multiple pixels P. The pixel electrodes 114 and TFT 116 constitute the pixel P. The pixel electrode 114 is a transparent electrode such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The TFT 116 is a switching element.

[0040] The first alignment layer 118 is provided on the liquid crystal layer 130 side of the first support substrate 112. The first alignment layer 118 covers the pixel electrode 114, the TFT 116, and the first wiring 105. The first alignment layer 118 is, for example, an inorganic alignment layer such as a silicon oxide layer, or an organic alignment layer such as a polyimide layer.

[0041] The liquid crystal layer 130 is provided between the element substrate 110 and the opposing substrate 140. A liquid crystal having positive or negative dielectric anisotropy is sealed in the gap between the element substrate 110 and the opposing substrate 140 to form the liquid crystal layer 130.

[0042] The opposing substrate 140 is located on the side of the liquid crystal layer 130 opposite to the element substrate 110. The opposing substrate 140 faces the element substrate 110. Light emitted from the light source is incident on the opposing substrate 140.

[0043] The opposing substrate 140 includes, for example, a second support substrate 141, a trim portion 142, an insulating layer 143, an opposing electrode 144, and a second orientation layer 145.

[0044] The second support substrate 141 faces the first support substrate 112. The second support substrate 141 supports the trim portion 142 and the insulating layer 143. The second support substrate 141 is, for example, a glass substrate, a quartz substrate, etc. The second support substrate 141 transmits light emitted from the light source. Viewed from the normal direction, the area of ​​the second support substrate 141 is, for example, smaller than the area of ​​the first support substrate 112.

[0045] The trim section 142 is provided on the liquid crystal layer 130 side of the second support substrate 141. As shown in Figure 4, the trim section 142 overlaps with the inspection circuit 103 and the scan line drive circuit 104 when viewed from the normal direction. The trim section 142 shields light from incident light from the opposing substrate 140 side from incident on peripheral circuits such as the inspection circuit 103 and the scan line drive circuit 104. This suppresses malfunctions of the peripheral circuits. Furthermore, the trim section 142 reduces the incidence of unnecessary stray light into the display area E. This suppresses a decrease in the contrast of the liquid crystal panel 42.

[0046] As shown in Figure 5, the insulating layer 143 is provided on the liquid crystal layer 130 side of the second support substrate 141. The insulating layer 143 covers the trim portion 142. The insulating layer 143 is provided between the liquid crystal layer 130 and the second support substrate 141. The surface of the insulating layer 143 on the liquid crystal layer 130 side is, for example, a flat surface. The insulating layer 143 transmits light emitted from a light source. The insulating layer 143 is, for example, a silicon oxide layer.

[0047] The counter electrode 144 is provided on the liquid crystal layer 130 side of the insulating layer 143. The counter electrode 144 is provided between the liquid crystal layer 130 and the insulating layer 143. The counter electrode 144 is a transparent electrode such as ITO or IZO.

[0048] The second alignment layer 145 is provided on the liquid crystal layer 130 side of the counter electrode 144. The liquid crystal layer 130 is provided between the first alignment layer 118 and the second alignment layer 145. The second alignment layer 145 is, for example, an inorganic alignment layer such as a silicon oxide layer, or an organic alignment layer such as a polyimide layer.

[0049] The liquid crystals constituting the liquid crystal layer 130 modulate the incident light and enable grayscale display by changing the orientation and order of the molecular aggregates depending on the voltage level applied between the pixel electrode 114 and the counter electrode 144. For example, in normally white mode, the transmittance to incident light decreases according to the voltage applied to each pixel P. In normally black mode, the transmittance to incident light increases according to the voltage applied to each pixel P, and as a whole, the display device 100 emits light with contrast corresponding to the video signal. In the example shown in Figure 1, the liquid crystal panel 42 is transmissive, but it may also be reflective.

[0050] Figure 6 is a schematic cross-sectional view of the display device 100 taken along the line VI-VI' in Figure 3. For convenience, Figure 6 shows the side of the second light guide 72 of the light detection device 70 from the sealing material 120 on the VI side. Also, in Figure 6, components other than the liquid crystal panel 42, the second light guide 72, and the index matching material 4 are not shown. Furthermore, the liquid crystal panel 42 is shown in a simplified manner in Figure 6.

[0051] As shown in Figure 6, the liquid crystal panel 42 further includes, for example, a first dustproof substrate 150 and a second dustproof substrate 152. The first dustproof substrate 150 is provided on the opposite side of the element substrate 110 from the liquid crystal layer 130. The element substrate 110 is provided between the first dustproof substrate 150 and the liquid crystal layer 130. The second dustproof substrate 152 is provided on the opposite side of the opposing substrate 140 from the liquid crystal layer 130. The opposing substrate 140 is provided between the second dustproof substrate 152 and the liquid crystal layer 130. The dustproof substrates 150 and 152 transmit light from a light source. The material of the dustproof substrates 150 and 152 is, for example, glass. Even if dust adheres to the surface of the dustproof substrates 150 and 152, it becomes out of focus, making the dust invisible.

[0052] The liquid crystal panel 42 has a first surface 42a to which light BL, which is blue light, is incident, and a second surface 42b that intersects with the first surface 42a. In the illustrated example, the first surface 42a is made of a second dustproof substrate 152. The first surface 42a is a surface facing the normal direction. In the illustrated example, the first surface 42a is facing in the +Z axis direction. The second surface 42b is connected to the first surface 42a. In the illustrated example, the second surface 42b is perpendicular to the first surface 42a. The second surface 42b is a surface facing in a direction perpendicular to the normal direction. In the illustrated example, the second surface 42b is facing in the +X axis direction. The second surface 42b is a side surface of the liquid crystal panel 42.

[0053] As shown in Figures 2 and 3, the COF 44 is connected to the liquid crystal panel 42. The COF 44 has a drive IC 44a that drives the liquid crystal panel 42. Furthermore, the COF 44 has a connector 44b. The connector 44b may include a reinforcing plate. Although not shown, the connector 44b may be connected to a circuit board 96.

[0054] The holder 46 supports the liquid crystal panel 42. In other words, the holder 46 houses the liquid crystal panel 42. The end of the COF 44 opposite to the connector 44b is inserted, for example, into a recess formed in the holder 46. The material of the holder 46 is, for example, metal, resin, etc.

[0055] The holder 46 has an opening 46a. When viewed from the normal direction, the opening 46a overlaps with the display area E of the liquid crystal panel 42. The opening 46a is formed on the side of the second dustproof substrate 152.

[0056] The holder 46 has bolt holes 46b formed therein. In the illustrated example, four bolt holes 46b are formed. Bolts (not shown) are inserted into the bolt holes 46b. The bolts support the holder 46 within the optical component housing 80, allowing for precise alignment with respect to the cross dichroic prism 50.

[0057] Figure 7 is a schematic side view of the display device 100, viewed from the direction of arrow VII in Figure 3. For convenience, Figure 7 omits the illustration of components other than the liquid crystal panel 42 and the holder 46. Also, in Figure 7, the liquid crystal panel 42 is shown as a dashed line for transparency and for simplification. When viewed from the direction of arrow VII in Figure 5, the liquid crystal panel 42 is basically hidden by the holder 46 and not visible. The same applies to Figures 14 and 16, which will be described later.

[0058] As shown in Figures 3 and 7, the holder 46 has a through hole 46c. The through hole 46c is located on the side of the liquid crystal panel 42 and is formed in the holder 46. As shown in Figure 3, the display area E of the liquid crystal panel 42 has a shape with a longitudinal direction and a transverse direction when viewed from the normal direction. The shape of the display area E is, for example, a rectangle with a long side Ea and a short side Eb. The through hole 46c is provided on the transverse side Eb side of the display area E. Therefore, the optical PL can be detected by simply integrating along the longer of the two transverse sides of the display area E, Ea. This allows for accurate detection of the degree of degradation of the liquid crystal panel 42. When viewed from the normal direction, the through hole 46c overlaps with the second surface 42b of the liquid crystal panel 42 that constitutes the transverse side Eb. The through hole 46c is, for example, chamfered. This allows for easy insertion of the second light guide 72 into the through hole 46c. In the example shown in Figure 7, the through-hole 46c overlaps with the second dustproof substrate 152 when viewed from the X-axis direction. The through-hole 46c does not overlap with the liquid crystal layer 130 when viewed from the X-axis direction.

[0059] Although not shown in the diagram, the through-hole 46c may overlap with the opposing substrate 140 as long as it does not overlap with the liquid crystal layer 130. Furthermore, the light incident surface 72a of the second light guide 72 may be provided on the long side Ea of the display area E of the liquid crystal panel 42.

[0060] The above describes the liquid crystal panel 42 of the optical modulator 40B. However, the configuration of the liquid crystal panel 42 of the optical modulators 40R and 40G is basically the same as that of the liquid crystal panel 42 of the optical modulator 40B, except that the holder 46 has a through hole 46c formed in it. For cost reduction, the optical modulators 40R and 40G may use a holder 46 with a through hole 46c formed in it.

[0061] 1.3. Calibration light source and light-shielding cap As shown in Figure 2, a calibration light source 160 is provided outside the outer casing 81. The calibration light source 160 emits light CL for calibrating the light detection unit 74 of the light detection device 70. The intensity of the light CL emitted from the calibration light source 160 is greater than, for example, the intensity of the light BL incident on the liquid crystal panel 42 of the light modulation device 40B. The calibration light source 160 is, for example, a laser or an LED (Light Emitting Diode).

[0062] The optical light CL emitted from the calibration light source 160 is guided into the outer casing 81, for example, via an optical fiber 162. The optical fiber 162 is connected to a connection part 82 fixed to the outer casing 81 via a connector 164. The connector 164 is detachable from the connection part 82. The connection part 82 penetrates the outer casing 81.

[0063] As shown in Figure 3, when the connector 164 is removed from the connection part 82 and the light-shielding cap 170 is connected to the connection part 82 as shown in Figure 3, no light CL enters the outer housing 81. The light-shielding cap 170 prevents light CL from entering the first light guide part 71. The light-shielding cap 170 is connected to the connection part 82 by, for example, a screw type or a latch mechanism. The material of the light-shielding cap 170 is, for example, metal or resin. Using a screw type or a latch mechanism to attach the light-shielding cap 170 prevents it from falling off unintentionally.

[0064] 1.4. Light detection device As shown in Figures 2 and 3, the light detection device 70 includes, for example, a first light guide unit 71, a second light guide unit 72, and a photodetector 73.

[0065] As shown in Figure 2, the first light guide 71 guides the light CL emitted from the calibration light source 160 to the photodetector 73's photodetector 74. The first light guide 71 is, for example, an optical fiber. In the illustrated example, one end of the first light guide 71 is connected to the connector 82. The other end of the first light guide 71 is inserted into the photodetector 73. In the illustrated example, the first light guide 71 passes through an opening 97 formed in the circuit board 96. The light CL emitted from the calibration light source 160 enters the photodetector 74 via the first light guide 71.

[0066] As shown in Figure 3, the second light guide 72 guides light PL from the liquid crystal panel 42 to the light detection unit 74 of the photodetector 73. The second light guide 72 is, for example, an optical fiber. One end of the second light guide 72, the light incident surface 72a, is inserted into a through hole 46c formed in the holder 46. The light incident surface 72a is located on the short side Eb of the liquid crystal panel 42. The light emission surface 72b of the second light guide 72 is inserted into the photodetector 73. The diameter D1 of the first light guide 71 is, for example, smaller than the diameter D2 of the second light guide 72.

[0067] As shown in Figure 6, the second light guide 72 has a core 72c and a cladding 72d surrounding the core 72c. When blue light BL is incident on the liquid crystal layer 130, the second light guide 72 guides the light PL emitted from the degradation material 132 of the liquid crystal layer 130 to the photodetector 73. Specifically, the light PL is incident on the second light guide 72 from the light incident surface 72a, passes through the boundary between the core 72c and the cladding 72d while being reflected, is emitted from the light emission surface 72b, and is incident on the photodetector 74. Although not shown in the figure, the first light guide 71 is also composed of a core and cladding.

[0068] As shown in Figure 6, degradation material 132 is generated in the liquid crystal layer 130 as time passes with light incidence. Degradation material 132 is a substance generated when blue light BL is irradiated onto the liquid crystal layer 130. When blue light BL is incident on the liquid crystal layer 130, the degradation material 132 emits photoluminescence PL. Photoluminescence PL is, for example, red light. Photoluminescence PL is photoluminescence (phosphorescence) in the degradation material 132. Photoluminescence PL is emitted from the degradation material 132 in a generally isotropic manner.

[0069] The light incident surface 72a of the second light guide unit 72 faces the second surface 42b of the liquid crystal panel 42. In the illustrated example, the second surface 42b has the surface of the element substrate 110, the surface of the sealing material 120, the surface of the opposing substrate 140, and the surfaces of the dustproof substrates 150 and 152. Furthermore, the second surface 42b may also have the surfaces of the alignment layers 118 and 145, and the surface of the opposing electrode 144. The light incident surface 72a is, for example, parallel to the second surface 42b. In the illustrated example, the second light guide unit 72 is provided so as to be parallel to the X-axis.

[0070] An index matching material 4 is placed between the light incident surface 72a of the second light guide unit 72 and the second surface 42b of the liquid crystal panel 42. The difference in refractive index between the index matching material 4 and the core 72c is smaller than the difference in refractive index between air and the core 72c. The index matching material 4 is made of, for example, a silicon-based material. The index matching material 4 can reduce the reflection of light PL at the light incident surface 72a of the second light guide unit 72. Furthermore, even if there are irregularities on the second surface 42b due to the manufacturing process, the reflection due to such irregularities can be reduced by the index matching material 4. This allows the light incident surface 72a to be positioned in a desired orientation.

[0071] The light incident surface 72a of the second light guide unit 72 does not overlap with the sealing material 120 when viewed from the Y-axis direction. The light incident surface 72a is not located on the side of the sealing material 120. Therefore, attenuation of the light PL detected by the light detection unit 74 by passing through the sealing material 120 can be suppressed. Furthermore, variations in the attenuation rate of the light PL caused by manufacturing variations in the width of the sealing material 120 can be reduced. In the illustrated example, the light incident surface 72a overlaps with the second dustproof substrate 152 when viewed from the Y-axis direction. Although not shown in the illustration, the light incident surface 72a may also overlap with the opposing substrate 140 when viewed from the Y-axis direction.

[0072] The photodetector 73 is provided inside the optical component housing 80, as shown in Figures 2 and 3. The photodetector 73 includes, for example, a photodetector 74, a wavelength filter 75, and a light shield 76. The photodetector 73 may be provided outside the optical component housing 80 or outside the outer casing 81.

[0073] As shown in Figure 2, the photodetector 74 detects light CL incident from outside the outer casing 81 when light CL is emitted from the calibration light source 160. Furthermore, as shown in Figure 3, the photodetector 74 detects light PL emitted from the second surface 42b of the liquid crystal panel 42 when light BL is incident on the liquid crystal layer 130. This reduces the amount of light BL in the first wavelength range incident on the photodetector 74 compared to, for example, detecting long-wavelength light PL emitted in the normal direction by the photodetector. Blue light BL includes, for example, light in the first wavelength range of 430 nm to 490 nm. Light PL and light CL include, for example, light in the longer wavelength range of 550 nm to 650 nm, which is longer than the first wavelength range. The photodetector 74 is, for example, a photodiode, a camera, a spectrometer, etc.

[0074] The wavelength filter 75 is provided between the light-emitting surface 72b of the second light guide unit 72 and the light-detecting unit 74. The wavelength filter 75 is, for example, a wavelength cut filter that transmits light PL and reduces light BL. The wavelength filter 75 may completely cut out light BL.

[0075] The light shield 76 houses the photodetector 74 and the wavelength filter 75. The light shield 76 surrounds the photodetector 74 and the wavelength filter 75. The first light guide 71 and the second light guide 72 pass through the light shield 76. The material of the light shield 76 is, for example, metal or resin.

[0076] A connecting cable 98 is connected to the photodetector 74 of the photodetector 70. The connecting cable 98 transmits the detection signal from the photodetector 74, which has been converted into an electrical signal, to the detection signal processing unit 92. The connecting cable 98 is connected to a connector 99 through an opening 97 formed in the circuit board 96. The connector 99 is electrically connected to the detection signal processing unit 92 and the central control unit 93. The detection signal processing unit 92 and the central control unit 93 are provided on the circuit board 96. The circuit board 96 may be provided so as to cover the cross dichroic prism 50. By passing the connecting cable 98 through the opening 97, the wiring length of the connecting cable 98 can be shortened.

[0077] 1.5. Time-dependent changes in liquid crystal panels and photoluminescence Figure 8 is a graph illustrating the time-dependent change in photoluminescence when a liquid crystal layer is irradiated with blue light. In Figure 8, the horizontal axis represents the measured wavelength, and the vertical axis represents the synchrotron radiation intensity observed from the liquid crystal layer irradiated with blue light. The initial spectrum when the liquid crystal layer is first irradiated with blue light is shown by the solid line L0, and the spectrum after a certain period of time of blue light irradiation is shown by the dashed line L1. Spectra other than those corresponding to the incident light are presumed to be based on the photoluminescence of degradation materials generated in the liquid crystal layer. Figure 8 and Figures 9 to 11, described later, show cases where both blue light and photoluminescence are detected.

[0078] As shown in Figure 8, when a liquid crystal layer is continuously irradiated for a certain period of time with blue light having an intensity peak around 450 nm, the intensity of the spectrum of synchrotron radiation emitted from the liquid crystal layer increases. In particular, the intensity in the wavelength band from 550 nm to 650 nm increases, and the synchrotron radiation is observed as light with an increased proportion of red components. When electrons transition between liquid crystal molecules, a predetermined amount of light is emitted, but it is presumed that when degradation substances are involved due to photochemical reactions, etc., synchrotron radiation including phosphorescence in the wavelength range of 550 nm to 650 nm is emitted.

[0079] Figures 9 and 10 are graphs illustrating the time-dependent changes in photoluminescence during accelerated degradation tests of liquid crystal panels. Figure 9 shows the spectra for test times T0, T1, T2, T3, and T4, respectively. In Figure 9, the horizontal axis represents the measurement wavelength, and the vertical axis represents the synchrotron radiation intensity observed from the liquid crystal layer. Figure 10 shows the time-dependent changes in synchrotron radiation intensity in the bandwidth from 500 nm to 650 nm. In Figure 10, the horizontal axis represents the test time, and the vertical axis represents the synchrotron radiation intensity in the aforementioned wavelength range observed from the liquid crystal layer. Figure 10 shows the corresponding points for test times T0, T1, T2, T3, and T4 shown in Figure 9. In the accelerated degradation tests shown in Figures 9 and 10, a high-luminosity blue light is irradiated onto the liquid crystal panel, and the synchrotron radiation from the liquid crystal panel is observed from the incident light side.

[0080] Figure 11 is a graph illustrating the electro-optical characteristics (VT characteristics) of a liquid crystal panel. In Figure 11, the vertical axis represents transmittance, and the horizontal axis represents the applied voltage to the liquid crystal layer of the liquid crystal panel. Figure 11 shows the VT curves of the liquid crystal panel corresponding to test times T0, T3, and T4, respectively.

[0081] The main factor for the change over time of the radiated light intensity observed in the liquid crystal panel is the change over time of the photoluminescence intensity from the liquid crystal panel. The test time T0 indicates the initial state, and T0 < T1 < T2 < T3 < T4. By irradiating with blue light, the intensity of the spectrum of the radiated light due to photoluminescence increases. At test times T1 and T2, the intensity of photoluminescence increases in the wavelength band from 500 nm to 650 nm. At test times T3 and T4, the intensity of photoluminescence in the entire measured wavelength range further increases, and the intensity of photoluminescence in the wavelength band from 500 nm to 650 nm increases significantly. For example, the test times T3 and T4 are 1.1 times and 1.2 times the time of test time T2, respectively. The intensity of photoluminescence at test times T3 and T4 is, for example, 1.5 times and more than 3 times the intensity of photoluminescence at test time T2, respectively. The V-T curve of the liquid crystal panel at test time T3 changes in the dark direction, and the V-T curve of the liquid crystal panel at test time T4 changes in the bright direction, and the display quality of the liquid crystal panel deteriorates. It can be seen that the deterioration of the liquid crystal panel progresses rapidly from test time T3. Therefore, the degree of deterioration of the liquid crystal panel can be grasped by the change in the intensity of photoluminescence.

[0082] In addition, as a factor for the increase in the intensity of photoluminescence from the liquid crystal panel, it is presumed that the concentration of the deteriorated substances in the liquid crystal layer increases. After test time T4, the deterioration further progresses, and the liquid crystal panel can no longer recover the display quality even with correction or the like, and the life of the liquid crystal panel will end. As a determination of the life, for example, as shown in FIG. 10, the point when the intensity I0 of the photoluminescence observed between test time T2 and test time T3 is detected is determined as the life of the liquid crystal panel. The intensity I0 of the photoluminescence can be set to the limit value I0 corresponding to the liquid crystal panel.

[0083] Therefore, by detecting the intensity of photoluminescence emitted from the liquid crystal panel, it is possible to monitor the degradation of the liquid crystal layer and the degradation of the liquid crystal panel caused by the degradation of the liquid crystal layer. Furthermore, if the liquid crystal layer is continuously irradiated with blue light for a certain period of time, the emitted light from the liquid crystal panel will also include fluorescence with wavelengths of 600 nm to 650 nm. Additionally, degradation due to photochemical reactions and other factors progresses more easily with shorter wavelengths of light irradiated onto the liquid crystal layer.

[0084] 1.6. Operation Next, the operation of the display device 100 according to this embodiment will be described with reference to the drawings. Figure 12 is a flowchart illustrating the operation of the display device 100 according to this embodiment.

[0085] The user, for example, operates an operating unit (not shown) to output a processing start signal to the control unit 90 to initiate processing. The operating unit consists of, for example, a mouse, keyboard, or touch panel. Before outputting the processing start signal, the user ensures that the connector 164 is connected to the connection unit 82, as shown in Figure 2. Upon receiving the processing start signal, the control unit 90 begins processing.

[0086] First, the control unit 90 causes the calibration light source 160 to emit optical light CL (step S1), as shown in Figure 12. The optical light CL travels to the optical detection unit 74 via the first optical guide unit 71, as shown in Figure 2, and is detected by the optical detection unit 74. Note that the emission of optical light CL from the calibration light source 160 may be controlled by an external device rather than by the control unit 90.

[0087] Next, the control unit 90 calculates a correction coefficient to correct the detected value of light PL based on the detected value of light CL detected by the photodetector 74 (step S2). The intensity of light CL emitted from the calibration light source 160 is known. For example, if the intensity of light CL emitted from the calibration light source 160 is I A Therefore, the intensity of the light CL detected by the light detection unit 74 is I B If so, the control unit 90 sets the correction coefficient to I A / I BThis is how it is calculated. In other words, this correction factor is the known intensity I A Detection Intensity I A This is a correction coefficient. If the sensitivity curve of the photodetector 74 with respect to wavelength is known, this correction coefficient can be applied to any wavelength range to perform the correction.

[0088] Next, the control unit 90 stores the calculated correction coefficient in the storage unit 95 (step S3). The control unit 90 may also display the calculated correction coefficient on a display unit (not shown). The display unit is composed of, for example, an LCD (Liquid Crystal Display), an organic EL (Electroluminescence) display, an EPD (Electrophoretic Display), or a touch panel display. After the user confirms the display on the display unit, the user removes the connector 164 from the connection unit 82 and attaches the light-shielding cap 170 to the connection unit 82 as shown in Figure 3. As a result, the connection unit 82 is shielded from light, and the incidence of light CL to the first light guide unit 71 is suppressed.

[0089] Next, the light source control unit 91 of the control unit 90 emits light from the light source device 10 (step S4). As a result, light BL is incident on the liquid crystal panel 42 of the light modulator 40B. Specifically, light BL is incident on the liquid crystal layer 130 of the liquid crystal panel 42. When the liquid crystal layer 130 is irradiated with light BL, it emits light PL from the degradation material 132. The light PL reaches the light detection unit 74 via the second light guide unit 72 and is detected by the light detection unit 74.

[0090] Next, the detection signal processing unit 92 of the control unit 90 corrects the detected value of optical PL detected by the photodetector 74 based on the detected value of optical CL detected by the photodetector 74 (step S5). Specifically, the control unit 90 reads the correction coefficient calculated in step S2 from the storage unit 95 and uses the read correction coefficient to correct the detected value of optical PL detected by the photodetector 74.

[0091] Next, the degradation determination unit 94 of the control unit 90 performs a process to determine whether the corrected light PL intensity exceeds a predetermined value (step S6). This predetermined value may be set considering the limit value I0 shown in Figure 10. The display device 100 may be configured to perform the process in step S6 automatically after a predetermined time has elapsed since the light emission from the light source device 10 began. Such a configuration can be realized by executing a program using a microcomputer or the like.

[0092] If the control unit 90 determines that the corrected light PL intensity does not exceed a predetermined value (NO in step S6), it returns to step S5. Then, in step S6, it repeats steps S5 and S6 until it determines that the corrected light PL intensity exceeds a predetermined value.

[0093] On the other hand, if the control unit 90 determines that the corrected light PL intensity exceeds a predetermined value (YES in step S6), it performs a process to notify the user that the liquid crystal panel 42 has reached the end of its lifespan (step S7). Specifically, the control unit 90 displays on a display unit (not shown) that the liquid crystal panel 42 has reached the end of its lifespan, or the period until it is expected to reach the end of its lifespan. The user, for example, performs maintenance on the liquid crystal panel 42 after receiving notification from the control unit 90. The control unit 90 may store the determination result in the storage unit 95, or it may transmit the determination result to a server on the network for recording via a communication means (not shown).

[0094] Then, the control unit 90 terminates the process.

[0095] Furthermore, if the corrected light PL intensity is determined to exceed a predetermined value, the control unit 90 may, for example, reduce the output of the light source device 10. This slows down the deterioration of the liquid crystal panel 42, allowing ample time for user maintenance.

[0096] 1.7. Effects The display device 100 includes an outer casing 81, a liquid crystal panel 42 of an optical modulator 40B provided inside the outer casing 81 which emits optical PL as a second light containing light in a longer wavelength range than the first wavelength range when optical BL as a first light containing light in a first wavelength range is incident on it, an optical detection unit 74 which detects optical PL and optical CL as a third light incident from outside the outer casing 81, a first optical guide unit 71 which guides optical CL to the optical detection unit 74, and a control unit 90 which corrects the detected value of optical PL detected by the optical detection unit 74 based on the detected value of optical CL detected by the optical detection unit 74.

[0097] Therefore, the display device 100 can correct the detected value of optical PL using the detected value of optical CL, thereby enabling accurate detection of the degree of degradation of the liquid crystal panel 42. For example, even if the sensitivity of the optical detection unit 74 varies, or if there are variations in the amplifiers and A / D (Analog / Digital) converters included in the circuit board 96, the degree of degradation of the liquid crystal panel 42 can be detected accurately. Furthermore, since there is no need to provide the calibration light source 160 that emits optical CL inside the outer casing 81, costs can be reduced.

[0098] In the display device 100, optical CL includes light in the longer wavelength range than the first wavelength range. Therefore, in the display device 100, the detected value of optical PL can be corrected using light in the same wavelength range as optical PL, and the degree of degradation of the liquid crystal panel 42 can be detected with high accuracy.

[0099] The display device 100 has a light-shielding cap 170 that suppresses the incidence of light CL onto the first light guide section 71. Therefore, the display device 100 can suppress the incidence of ambient light onto the light detection section 74, and can detect light PL with high accuracy.

[0100] The display device 100 calculates a correction coefficient to correct the detected value of optical PL based on the detected value of optical CL. Therefore, the display device 100 can calculate the absolute value of the intensity of optical PL and accurately detect the degree of degradation of the liquid crystal panel 42.

[0101] The display device 100 has a storage unit 95 in which correction coefficients are stored. Therefore, the display device 100 can read the correction coefficient calculated from the storage unit 95 and correct the detected value of the optical PL.

[0102] The display device 100 has a second light guide unit 72 that guides light PL to the light detection unit 74. Therefore, the display device 100 can efficiently guide light PL to the light detection unit 74.

[0103] In the display device 100, the diameter D1 of the first light guide 71 is smaller than the diameter D2 of the second light guide 72. Therefore, in the display device 100, the allowable curvature of the first light guide 71 can be reduced, which increases the flexibility of wiring within the outer casing 81. This increases the flexibility of the arrangement of the connection parts 82, for example, allowing the connection parts 82 to be integrated with the interfaces of various signals. Since the calibration light source 160 can be set to have a higher output than the light source device 10, the light detection unit 74 can sufficiently detect the light CL emitted from the calibration light source 160 even if the diameter D1 of the first light guide 71 is small.

[0104] The display device 100 has a light-shielding body 76 surrounding the light detection unit 74. Therefore, the display device 100 can suppress the incidence of ambient light on the light detection unit 74, and can detect optical light (PL) with high accuracy.

[0105] The display device 100 has a wavelength filter 75 provided between the light-emitting surface 72b of the second light guide unit 72 and the light detection unit 74, which reduces light in the first wavelength range. Therefore, the display device 100 can reduce the light in the first wavelength range incident on the light detection unit 74, and can detect optical PL with high accuracy.

[0106] 2. Variations of display devices 2.1. First Variation Next, a display device according to the first modified example of this embodiment will be described with reference to the drawings. Figure 13 is a schematic cross-sectional view showing the display device 200 according to the first modified example of this embodiment. Figure 14 is a schematic side view showing the display device 200 according to the first modified example of this embodiment. For convenience, in Figure 13, the illustration of components other than the liquid crystal panel 42, the second light guide unit 72, and the index matching material 4 is omitted. Also, in Figure 14, the illustration of components other than the liquid crystal panel 42 and the holder 46 is omitted. Furthermore, in Figures 13 and 14, the liquid crystal panel 42 is shown in a simplified form.

[0107] Hereinafter, in the display device 200 according to the first modified example of this embodiment, components having the same function as the components of the display device 100 described above will be denoted by the same reference numerals, and their detailed descriptions will be omitted.

[0108] In the display device 100 described above, as shown in Figures 6 and 7, the light incident surface 72a and the through hole 46c of the second light guide section 72 overlapped with the second dustproof substrate 152 when viewed from a direction perpendicular to the normal direction.

[0109] In contrast, in the display device 200, the light incident surface 72a of the second light guide section 72 overlaps with the first dustproof substrate 150 when viewed from a direction perpendicular to the normal direction, as shown in Figure 13. The through hole 46c also overlaps with the first dustproof substrate 150 when viewed from a direction perpendicular to the normal direction, as shown in Figure 14.

[0110] In the example shown in Figure 13, the second light guide 72 is provided at an angle with respect to the X-axis direction. The second light guide 72 is tilted so that its light incident surface 72a faces the liquid crystal layer 130. The light incident surface 72a of the second light guide 72 has a perpendicular line Q that intersects with the liquid crystal layer 130. Therefore, in the display device 200, the light incident surface 72a of the second light guide 72 can efficiently capture light PL compared to the case where the light incident surface does not have a perpendicular line that intersects with the liquid crystal layer.

[0111] In the example shown in Figure 14, the second dustproof substrate 152 and the inner wall of the holder 46 are bonded together with a thermally conductive adhesive 6. As shown in Figure 14, the thermally conductive adhesive 6 may wrap around to the side surface of the second dustproof substrate 152. Therefore, by forming the through hole 46c to overlap with the first dustproof substrate 150, the light PL can be efficiently incident on the light incident surface 72a of the second light guide 72 without being affected by the thermally conductive adhesive 6.

[0112] 2.2. Second Variation Next, a display device according to a second modified example of this embodiment will be described with reference to the drawings. Figure 15 is a schematic diagram showing a display device 300 according to a second modified example of this embodiment. Figure 16 is a schematic side view showing a display device 300 according to a second modified example of this embodiment, and is viewed from the direction of arrow XIV in Figure 15. For convenience, in Figure 16, the illustration of components other than the liquid crystal panel 42 and the holder 46 is omitted. Also, in Figure 16, the liquid crystal panel 42 is shown in a simplified manner.

[0113] In the following description of the display device 300 according to the second modified example of this embodiment, components having the same function as the components of the above-described display devices 100 and 200 are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0114] In the display device 100 described above, as shown in Figure 3, the second light guide unit 72 was an optical fiber.

[0115] In contrast, in the display device 300, as shown in Figure 15, the second light guide section 72 is configured such that the light shielding body 76 extends toward the liquid crystal panel 42. The second light guide section 72 is provided integrally with the light shielding body 76. Therefore, the amount of light PL guided to the light detection section 74 can be increased. It is preferable that the inner surface of the second light guide section 72 is covered with a reflective material formed by plating or the like. The light PL repeatedly reflects off the inner surface of the second light guide section 72 before reaching the light detection section 74.

[0116] A notch 346c is formed in the holder 46. In the example shown in Figure 16, the notch 346c exposes the first dustproof substrate 150 and the element substrate 110. The notch 346c can increase the amount of light PL to the second light guide 72.

[0117] As shown in Figure 15, a notch 346d is formed on the opposite side of the notch 346c of the holder 46. The notches 346c and 346d are formed symmetrically, for example, with respect to a line in the Y direction passing through the center of the display area E. Therefore, when the display device 300 is viewed, the sense of incongruity can be reduced. For example, if a notch is formed on one side and not on the other, the distribution of the thickness of the liquid crystal layer 130 in the display area E may become asymmetrical with respect to the display center due to differences in the stress distribution of the liquid crystal panel. In this case, the unevenness in the thickness of the liquid crystal layer 130 may be easily perceived as an unnatural color unevenness. The display device 300 can reduce such an unnatural feeling. Note that a through hole may be formed instead of a notch.

[0118] The embodiments and variations described above are examples only and are not limited thereto. For example, each embodiment and each variation can be combined as appropriate.

[0119] The present invention includes configurations substantially identical to those described in the embodiments, for example, configurations with the same function, method, and results, or configurations with the same purpose and effect. Furthermore, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as those described in the embodiments. Finally, the present invention includes configurations that add known technology to the configurations described in the embodiments.

[0120] The following can be derived from the embodiments and modifications described above.

[0121] One embodiment of a display device is, The outer casing and A liquid crystal panel provided within the outer casing, which emits second light including light in a longer wavelength range than the first wavelength range when first light including light in a first wavelength range is incident upon it, A light detection unit that detects the second light and a third light incident from outside the outer casing, A first light guide unit that guides the third light to the light detection unit, A control unit that corrects the detected value of the second light detected by the light detection unit based on the detected value of the third light detected by the light detection unit, It holds.

[0122] This display device can accurately detect the degree of degradation of the liquid crystal panel.

[0123] One embodiment of the above-mentioned display device, The third light may include light in a wavelength range longer than the first wavelength range.

[0124] This display device allows for the correction of the detected value of the second light source using light in the same wavelength range as the second light source, enabling accurate detection of the degree of degradation of the liquid crystal panel.

[0125] One embodiment of the above-mentioned display device, The device may have a light-shielding cap to suppress the incidence of the third light into the first light guide.

[0126] This display device can suppress the incidence of ambient light on the light detection unit, enabling accurate detection of the second light source.

[0127] One embodiment of the above-mentioned display device, The control unit may calculate a correction coefficient for correcting the detected value of the second light based on the detected value of the third light.

[0128] This display device can calculate the absolute value of the intensity of the second light, allowing for accurate detection of the degree of degradation of the liquid crystal panel.

[0129] One embodiment of the above-mentioned display device, The system may have a storage unit that stores the correction coefficient.

[0130] This display device allows the detection value of the second light to be corrected by reading a correction coefficient calculated from the memory unit.

[0131] One embodiment of the above-mentioned display device, The device may also have a second light guide that directs the second light to the light detection unit.

[0132] This display device allows for efficient guidance of the second light source to the photodetector.

[0133] One embodiment of the above-mentioned display device, The diameter of the first light guide portion may be smaller than the diameter of the second light guide portion.

[0134] This display device allows for a smaller allowable curvature of the first light guide, thereby increasing the flexibility of wiring within the outer casing.

[0135] One embodiment of the above-mentioned display device, The light detection unit may have a light-shielding body surrounding it.

[0136] This display device can suppress the incidence of ambient light on the light detection unit, enabling accurate detection of the second light source.

[0137] One embodiment of the above-mentioned display device, A wavelength filter may be provided between the light-emitting surface of the second light guide and the light-detecting unit to reduce light in the first wavelength range.

[0138] This display device can reduce the amount of light in the first wavelength range incident on the light detection unit, enabling accurate detection of the second light. [Explanation of Symbols]

[0139] 2…Screen, 4…Index matching material, 6…Thermal conductive adhesive, 10…Light source device, 20,22…Dichroic mirror, 24,26,28…Reflective mirror, 30,32,34,36,38…Relay lens, 40R,40G,40B…Optical modulator, 41a…First polarizing element, 41b…Second polarizing element, 42…Liquid crystal panel, 42a…First surface, 42b…Second surface, 44…COF, 44a…Driver IC, 44b…Connector, 46… Holder, 46a…Opening, 46b…Bolt hole, 46c…Through hole, 50…Cross dichroic prism, 60…Projection optical system, 62, 64, 66…Lenses, 70…Light detection device, 71…First light guide, 72…Second light guide, 72a…Light incident surface, 72b…Light exit surface, 72c…Core, 72d…Cladding, 73…Photodetector, 74…Light detection unit, 75…Wavelength filter, 76…Light shield, 80…Housing for optical components, 81…Outer housing, 82…Connection part 90...Control unit, 91...Light source control unit, 92...Detection signal processing unit, 93...Central control unit, 94...Degradation determination unit, 95...Storage unit, 96...Circuit board, 97...Opening, 98...Connection cable, 99...Connector, 100...Display device, 101...External connection terminal, 102...Data line drive circuit, 103...Inspection circuit, 104...Scan line drive circuit, 105...First wiring, 106...Second wiring, 110...Element substrate, 112...First support substrate, 114...Pixel electrode, 1 16…TFT, 118…First alignment layer, 120…Sealing material, 130…Liquid crystal layer, 132…Degradation material, 140…Opposite substrate, 141…Second support substrate, 142…Edge portion, 143…Insulating layer, 144…Opposite electrode, 145…Second alignment layer, 150…First dustproof substrate, 152…Second dustproof substrate, 160…Calibration light source, 162…Optical fiber, 164…Connector, 170…Light-shielding cap, 200, 300…Display device, 346c, 346d…Notch

Claims

1. The outer casing and A liquid crystal panel provided within the outer casing, which emits second light including light in a longer wavelength range than the first wavelength range when first light including light in a first wavelength range is incident upon it, A light detection unit that detects the second light and the third light incident from outside the outer casing, A first light guide unit that guides the third light to the light detection unit, A control unit that corrects the detected value of the second light detected by the light detection unit based on the detected value of the third light detected by the light detection unit, A display device having the following features.

2. In claim 1, The third light includes light in a wavelength range longer than the first wavelength range, and is used in a display device.

3. In claim 1, A display device having a light-shielding cap that suppresses the incidence of the third light into the first light guide portion.

4. In claim 1, The control unit is a display device that calculates a correction coefficient for correcting the detected value of the second light based on the detected value of the third light.

5. In claim 4, A display device having a storage unit in which the correction coefficient is stored.

6. In claim 1, A display device having a second light guide that guides the second light to the light detection unit.

7. In claim 6, A display device in which the diameter of the first light guide portion is smaller than the diameter of the second light guide portion.

8. In claim 1, A display device having a light-shielding body surrounding the light detection unit.

9. In claim 6, A display device having a wavelength filter provided between the light-emitting surface of the second light guide and the light-detecting unit, which reduces light in the first wavelength range.

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