JP6766525B2 - Display device - Google Patents

Description

The present invention relates to a display device.

The display device is provided with a heat radiating means for suppressing a temperature rise from the viewpoint of maintaining a suitable display.
For example, Patent Document 1 describes a heat conductive transparent member arranged on the surface of a liquid crystal panel, a holding frame for holding the liquid crystal panel, a fixing member for holding and fixing the holding frame, and heat dissipation attached to the fixing member. A display device with fins is disclosed. In this configuration, a part of the heat generated in the liquid crystal panel is transferred to the fixing member through the holding frame and the other part is transmitted to the fixing member through the transparent member, and is dissipated from the heat radiating fin.

Japanese Unexamined Patent Publication No. 2005-134858

In the display device disclosed in Patent Document 1, since the heat of the liquid crystal panel is transferred to the heat radiating fins through many members, the heat generated in the liquid crystal panel is transferred to the heat radiating fins at a slow speed, and the heat radiated by the heat radiating fins. The effect is not fully exhibited.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display device having ensured heat resistance.

In order to achieve the above object, the display device of the present invention
A display member including a display surface that emits display light corresponding to an image,
A heat storage member having thermal conductivity arranged at a position on the display surface of the display member so as not to block the display light,
An adhesive layer having thermal conductivity provided between the display member and the heat storage member,
Equipped with a,
The heat storage member has a frame-like shape along the outer peripheral edge of the display member and has a frame-like shape.
The inner surface of the heat storage member has a gradient in a direction in which the cross-sectional area of the heat storage member is reduced toward the display surface of the display member .

According to the present invention, since the heat of the display member is quickly and sufficiently transferred to the heat storage member, it is possible to provide a display device having ensured heat resistance.

It is a schematic diagram of the vehicle equipped with the HUD (head-up display) device which concerns on 1st Embodiment of this invention. It is the schematic which shows the structure of the HUD apparatus which concerns on 1st Embodiment of this invention. It is a top view projected from the projection direction of the display light L of the display unit which concerns on each embodiment of this invention. It is an IV-IV sectional view in FIG. 3 of the display unit which concerns on 1st Embodiment of this invention. It is a graph which showed the temperature change of the display member which concerns on 1st Embodiment of this invention. It is a top view which showed the moving path of the focal point which concerns on 1st Embodiment of this invention. It is an IV-IV sectional view in FIG. 3 of the display unit which concerns on the modification of 1st Embodiment of this invention. FIG. 5 is a sectional view taken along line IV-IV in FIG. 3 of a display unit according to a second embodiment of the present invention. It is an IV-IV sectional view in FIG. 3 of the display unit which concerns on the modification of the 2nd Embodiment of this invention. It is a perspective view of the heat storage member which concerns on the modification of 2nd Embodiment of this invention. It is XI-XI sectional view in FIG. 3 of the display unit which concerns on the modification of 2nd Embodiment of this invention. It is an IV-IV sectional view in FIG. 3 of the display unit which concerns on 3rd Embodiment of this invention.

(First Embodiment)
A first embodiment in which the display device according to the present invention is embodied in a vehicle HUD (head-up display) device will be described with reference to the drawings.

As shown in FIG. 1, the HUD device 1 according to the present embodiment is mounted on the dashboard of the vehicle 2. The HUD device 1 projects the display light L onto the windshield 3, which is an example of the projection member in the vehicle 2. The viewer 4 receives the display light L reflected on the windshield 3 and can visually recognize the virtual image V superimposed on the actual scene seen through the windshield 3.

As shown in FIG. 2, the HUD device 1 includes a display unit 20, a light source unit 30, a plane mirror 60, a concave mirror 70, and a housing 10.

The housing 10 is formed in a box shape, for example, with a black light-shielding synthetic resin. A display unit 20, a light source unit 30, a plane mirror 60, and a concave mirror 70 are housed inside the housing 10. The housing 10 has an opening 11 at a position facing the windshield 3. The opening 11 is covered with a translucent cover 12.

The light source unit 30 is composed of, for example, a plurality of LEDs (Light Emitting Diodes), and irradiates the light from the LEDs toward the display unit 20. The LED is an example of a light source. The display unit 20 receives the light from the light source unit 30 to generate a display light L representing an image to be displayed, and irradiates the plane mirror 60 with the generated display light L. The specific configuration of the display unit 20 will be described later.

The plane mirror 60 is composed of a base material made of a synthetic resin, a glass material, or the like, and a reflective film formed on the surface of the base material by vapor deposition or the like.
The concave mirror 70 is formed in a curved concave shape, and is composed of, for example, a base material made of a synthetic resin material and a reflective film formed on the surface of the base material by vapor deposition or the like.
After being reflected by the plane mirror 60, the display light L is reflected by the concave mirror 70, passes through the translucent cover 12 of the housing 10, is reflected by the windshield 3, and reaches the viewer 4. As described above, the plane mirror 60 and the concave mirror 70 form an optical relay that guides the display light L from the display unit 20, or more accurately, the display member 21, which will be described later, to the windshield 3.

The display unit 20 includes a display member 21, a frame body 22, and a heat storage member 23, as shown in a plan view (FIG. 3) and a sectional view taken along line IV-IV (FIG. 4).

The display member 21 is composed of, for example, a transmissive TFT (Thin Film Transistor) liquid crystal display panel. The liquid crystal display panel includes, for example, a pair of polarizing plates (not shown) and a liquid crystal layer (not shown) having electrodes located between the polarizing plates. The display member 21 displays an image in the display area S of the display surface 21a (surface) by changing the transmittance of light from the light source unit 30.

The frame body 22 is configured as a bezel of the display member 21, and is formed of, for example, metal or resin. Further, the frame body 22 has a rectangular frame-like shape along the outer peripheral edge portion of the display member 21, and has an L-shaped cross section over the entire circumference. That is, the frame body 22 is connected to the first portion 22a facing the edge of the back surface (lower surface of FIG. 4) of the display member 21 and the first portion 22a, and extends along the side surface of the display member 21. A second portion 22b is provided. The first portion 22a and the back surface of the display member 21 are adhered to each other via an adhesive layer 25 composed of double-sided tape or an adhesive. The opening area Wa of the frame body 22 is larger than the display area S of the display member 21, and the frame body 22 is adhered to a position that does not block the display light L passing through the display area S of the display member 21.

The heat storage member 23 is a member that temporarily stores heat from the display member 21. Therefore, it is preferably composed of a material having a large heat capacity. Further, since the effect as a heat storage body is exhibited by spreading heat throughout the heat storage member 23, it is more preferable that the material is composed of a material having high thermal conductivity. The heat storage member 23 satisfying these conditions is composed of, for example, a cast product such as an aluminum alloy, an iron-based metal or a copper alloy, or a ceramic molded product.

The heat storage member 23 has a rectangular frame-like shape along the outer peripheral edge of the display member 21, and has a display surface of the display member 21 via a heat conductive adhesive layer 24 composed of a heat conductive adhesive. It is adhered to 21a. The heat storage member 23 overlaps the non-display area U surrounding the display area S in the display surface 21a of the display member 21. The non-display area U is an area in which the content is not displayed. The opening region Wb of the heat storage member 23 is larger than the display region S of the display member 21, and the heat storage member 23 is adhered to a position that does not block the display light L that has passed through the display region S of the display member 21.
Further, the inner surface of the heat storage member 23 is preferably subjected to antireflection treatment in order to prevent the generation of reflected light. As the antireflection treatment, a black plating treatment or a black alumite treatment can be considered.

Next, the heat capacity that the heat storage member 23 should have will be described with reference to FIGS. 5 and 6.

In a steady state, the heat storage member 23 is maintained at substantially the same temperature as the display member 21, and when a large or abnormal heat generation is temporarily generated in the display member 21, the heat storage member 23 absorbs and stores the generated heat to display the display member. It has a function of suppressing the temperature rise of 21. Therefore, as shown in FIG. 5, the heat storage member 23 absorbs the heat generated by the display member 21 at a constant steady operation temperature Tb in the steady operation state, and the display member 21 becomes abnormal at the reference time T1. It is desirable to have enough heat capacity to prevent it from reaching Th.

The display device according to this embodiment is a vehicle HUD device, and the most severe thermal condition is considered to be during the daytime in summer. Further, as the temporary heat generation of the display member 21, heat generation due to irradiation of strong external light such as sunlight can be considered. Specifically, as shown in FIG. 2, the sunlight Ls reaches the display member 21 by tracing the path of the display light L. Since the sunlight Ls is focused by the concave mirror 70, the focal point F is formed on the display member 21, and the heat generated in the vicinity of the focal point F becomes large. However, the focal point F moves on the display member 21 as the sun moves with the passage of time, and at the maximum, the time until the focal point F moves from one end point P1 of the display member 21 to the other end point P2. After that, the heat generated by the sunlight ends.

Therefore, in the present embodiment, the reference temperature Th is set to the Bonanza generation temperature at which the liquid crystal panel (display member 21) is blackened or the heat resistant temperature of the polarizing plate of the liquid crystal panel, and the steady operation temperature Tb is set to the display member during the summer day. The temperature in the steady state of 21 is set, the temporary heat generated by the display member 21 is set as the heat generated by the irradiation of sunlight, and the reference time T1 is the heat generation duration required for the focal point F of sunlight to pass over the display member 21. , And.
According to these settings, the heat capacity of the heat storage member 23 is the display unit even when heat is generated by sunlight during the reference time T1 while the display member 21 is at the steady operating temperature Tb, as shown in FIG. It is designed so that the temperature of the display member 21 does not exceed the reference temperature Th due to the heat dissipation and heat storage of the entire 20. The actual required heat capacity can be obtained by experiments, simulations, etc.

The heat capacity of the heat storage member 23 is determined by the product of specific heat, density and volume. The larger the heat capacity, the more the temperature rise of the display member 21 can be delayed. However, the larger the volume of the heat storage member 23, the lower the mountability. Therefore, in addition to the calorific value and the reference time T1, the specific heat, density, and volume of the heat storage member 23 are selected in consideration of this trade-off.

Next, the operation of the HUD device 1 according to the first embodiment will be described.
When the power of the HUD device 1 is turned on, the light source unit 30 irradiates the display unit 20 with light. The display unit 20 receives the light from the light source unit 30 to generate a display light L representing an image to be displayed, and irradiates the plane mirror 60 with the generated display light L. The plane mirror 60 reflects the display light L toward the concave mirror 70, and the concave mirror 70 reflects the display light L from the plane mirror 60 toward the windshield 3. The display light L reflected by the concave mirror 70 passes through the translucent cover 12 of the housing 10 and reaches the windshield 3, and the display light L reflected by the windshield 3 is visually recognized as shown in FIG. Reach person 4. By receiving the display light L, the viewer 4 can visually recognize the virtual image V displayed at the front position of the windshield 3.

Next, it is assumed that the HUD device 1 is used in the vehicle 2 that is irradiated with sunlight during the daytime in summer.

As shown in FIG. 5, the temperature of the display member 21 is the atmospheric temperature Ta of the vehicle 2 at the time t1 when the ignition switch of the vehicle 2 is turned on. Since the display member 21 absorbs a part of the light by its polarizing plate, it receives the light from the light source unit 30 and generates heat. Further, the display member 21 consumes electric power for displaying an image, so that it generates heat. When the focal point F of the sunlight Ls is not located on the display member 21, the temperature of the display member 21 maintains a balance between heat generation and heat dissipation, and becomes a steady state at the steady operating temperature Tb. Here, when the focus F of the sunlight Ls moves to the display member 21, for example, at time t2, the temperature of the display member 21 starts to rise, and the focus F of the sunlight Ls is located on the display member 21. At time t3 when the time (reference time T1) has elapsed, the temperature of the display member 21 reaches the maximum value Tc. Since the heat capacity of the heat storage member 23 is set as described above, the maximum temperature Tc is less than the reference temperature Th, and the display abnormality of the display member 21 and the abnormality of the constituent members do not occur.

After that, the focal point F of the sunlight Ls moves to the outside of the display member 21, so that the heat generated by the sunlight in the display member 21 disappears, and the temperature of the entire display unit 20 including the display member 21 gradually decreases due to heat dissipation. ..

As described above, in the present embodiment, the heat capacity of the heat storage member 23 is set so that the temperature of the display member 21 is kept below the reference temperature Th, so that a display abnormality occurs in the display member 21. There is nothing to do.

Further, since the heat storage member 23 is adhered to the display surface of the display member 21 by the heat conductive adhesive layer 24, the heat of the display member 21 is easily transferred quickly. As a result, the heat capacity of the entire display unit 20 is increased by the amount of the heat storage member 23, so that the temperature rise rate of the display member 21 due to the influence of the display light L, external light, or the like can be alleviated.
Further, since the heat storage member 23 does not block the display light L required for image display, there is no concern that a double image or the like is generated.

(Modified example of the first embodiment)
In the first embodiment, the heat storage member 23 has a frame shape in which the outer surface and the inner surface thereof are parallel to each other, but the shape is not limited to this and may be a shape that does not block the display light L. .. For example, as shown in FIG. 7, the inner side surface of the heat storage member 23 may be tilted with respect to the outer surface in accordance with the projection direction of the display light L. Further, the display area S may be covered. Further, although not shown, the heat storage member 23 may be divided into two or more parts.

Further, the setting of the heat capacity and the reference temperature Th of the heat storage member 23 in the first embodiment is an example, and how the heat storage member 23 is set as long as it contributes to the increase of the heat capacity of the entire display unit 20. Is also good.

It is desirable that the heat storage member 23 does not completely block the display light L. However, in the present embodiment, it is included in the "not blocking the display light" state as long as the light from the peripheral edge of the display area S does not significantly affect the displayed image that is visually recognized even if it is blocked. And. For example, there is no problem even if it blocks up to about 25% of the light from the display area S.

In the first embodiment, the heat storage member 23 is smaller than the outer dimensions of the frame body 22, but may be larger than the outer dimensions of the frame body 22.

When the display unit 20 is assembled to the HUD device 1, the HUD device 1 may hold the heat storage member 23.

The heat storage member 23 and / or the frame 22 may be provided with means (not shown) for dissipating heat to surrounding members or an external atmosphere.

The above-mentioned numerical values, for example, steady-state operating temperature Tb, reference temperature Th, reference time T1, shape, size, material, and the like are examples and can be changed as appropriate.

(Second Embodiment)
In the first embodiment, the heat storage member 23 is not arranged in the display area S of the display member 21. Therefore, the display area S cannot contribute to the increase in the heat capacity, and the heat generated in the display area S is difficult to be transmitted to the heat storage member 23 and the frame body 22 arranged on the back surface. Therefore, only the temperature of the display area S may rise locally.
Therefore, an embodiment of a display device having a configuration in which the heat capacity on the display area S is increased and the heat generated in the display area S is transferred to the heat storage member 23 with high thermal conductivity will be described below with reference to the drawings. In this embodiment, the differences from the first embodiment will be mainly described.
As shown in FIG. 8, the display unit 20 of the present embodiment includes a display member 21, a frame body 22, a heat storage member 23, a transparent member 26, and a heat conduction member 27.

The transparent member 26 is adhered to the display surface 21a of the display member 21 via the transparent adhesive layer 28. The transparent member 26 is formed in a rectangular plate shape, for example, in a plan view. The transparent member 26 is located on the optical path of the display light L, is larger than the display area S of the display member 21, and overlaps the entire display area S. Other conditions that the material and shape of the transparent member 26 should satisfy will be described later.

The transparent member 26 is located inside the heat storage member 23. The inner side surface of the heat storage member 23 and the side surface of the transparent member 26 face each other. A gap is formed between the inner surface of the heat storage member 23 and the side surface of the transparent member 26 so that the heat storage member 23 and the transparent member 26 can withstand deformation due to thermal expansion.

The heat conductive member 27 is arranged in a gap between the inner surface of the heat storage member 23 and the side surface of the transparent member 26. The heat conductive member 27 is, for example, a flexible heat conductive sheet made of silicon rubber, and has a size sufficient to fill a gap that may occur between the heat storage member 23 and the transparent member 26 in consideration of thermal expansion. Those with flexibility are selected.

Next, the material and shape of the transparent member 26 will be described.
Regarding the material of the transparent member 26 and the material and thickness of the transparent adhesive layer 28, the in-plane thermal resistance of the display member 21 when the transparent member 26 is bonded is equivalent to the in-plane thermal resistance of the display member 21 alone. Or it is selected so that it is less than its thermal resistance.
The thermal resistance in the in-plane direction is calculated by the following equation (1).
Thermal resistance in the in-plane direction = Distance between two points to be calculated in the in-plane / (Equivalent thermal conductivity in the in-plane direction x cross-sectional area) ... (1)
The cross-sectional area is the cross-sectional area between two points to be calculated of the composite material when the composite material composed of the display member 21 and the transparent member 26 is cut along the thickness direction thereof.
The in-plane equivalent thermal conductivity of the composite material is calculated by the following equation (2).
In-plane equivalent thermal conductivity = Σ (in-plane thermal conductivity of each layer x layer thickness x layer abundance ratio) / overall thickness ... (2)
The total thickness is the thickness of the composite material. The in-plane heat transfer coefficient of each layer is the thermal conductivity of the display member 21 and the transparent member 26. The layer thickness is the thickness of the display member 21 or the transparent member 26. The layer abundance ratio is the ratio of the material present to the layer thickness. The cross-sectional area and the in-plane heat transfer coefficient may be obtained as a composite material including a transparent adhesive.

Further, as shown in FIG. 5, the heat capacity of the entire display unit 20 including the display member 21, the heat storage member 23, and the transparent member 26 is increased so that the temperature of the display member 21 becomes lower than the reference temperature Th in the reference time T1. It will be adjusted.
The reference time T1 and the reference temperature Th are the same as those in the first embodiment.

The transparent member 26 may be made of a material having a lower thermal conductivity than the transparent member made of sapphire or crystal (quartz) disclosed in Patent Document 1. In general, a transparent material having a high thermal conductivity is expensive, so that the cost of the display unit 20 can be suppressed by using a transparent member having a low thermal conductivity. In consideration of these conditions, the material of the transparent member 26 may be a glass material, synthetic quartz, transparent zirconia, a transparent container filled with a phase change material, or the like.

According to the configuration of the present embodiment, the heat capacity of the display unit 20 as a whole is larger than that of the display unit 20 of the first embodiment by the transparent member 26 if other conditions are the same. Therefore, the temperature rise rate is suppressed.
Further, the thermal resistance of the display member 21 in the in-plane direction is at least the same or reduced. Therefore, the heat diffusion of the display member 21 becomes equal to or higher than that of the display member 21 of the first embodiment, and the temperature rise rate is further suppressed.

Further, by changing the material, thickness, volume, etc. of the heat storage member 23 and the transparent member 26, it is possible to meet various required heat dissipation characteristics and exterior requirements.
Since the flexible heat conductive member 27 is arranged between the heat storage member 23 and the transparent member 26, the heat storage member 23 and the transparent member 26 are in close contact with each other regardless of the heat expansion and contraction of the heat storage member 23 and the transparent member 26. , High thermal conductivity between the heat storage member 23 and the transparent member 26 can be ensured, and high thermal diffusivity can be obtained for the display unit 20 as a whole. Further, the design accuracy of the heat storage member 23 and the transparent member 26 can be provided with a margin.
Further, the side surface of the transparent member 26 has a gradient in a direction in which the cross-sectional area of the transparent member 26 expands toward the display surface 21a, and the inner side surface of the heat storage member 23 faces the display surface 21a of the heat storage member 23. It is desirable to have a gradient in the direction in which the cross-sectional area is reduced. As a result, when the transparent member 26, the heat conductive member 27, and the heat storage member 23 are assembled to the display member 21 in this order, the heat conductive member 27 has a gradient on the outer surface of the transparent member 26 and the inner surface of the heat storage member 23, respectively. It does not easily protrude from the display unit 20 and is easy to assemble.

(Modified example of the second embodiment)
In the second embodiment, an example in which the heat conductive member 27 formed in advance is arranged in the gap between the heat storage member 23 and the transparent member 26 is shown, but the manufacturing method is not limited to this. For example, a two-component curable type thermosetting grease, a thermosetting resin, a photocurable resin, or the like, which has flexibility even after curing, is injected into the gap between the heat storage member 23 and the transparent member 26, and then these are cured. By doing so, it is also possible to form the heat conductive member 27. According to this manufacturing method, the paste-like or gel-like heat conductive grease or the like spreads along the side wall of the heat storage member 23 or the transparent member 26, so that gaps are unlikely to occur and thermal resistance can be suppressed.
The heat conductive member 27 is not limited to a curable one, and is solidified by injecting a phase changing material that transitions between the solid phase and the liquid phase according to the temperature in the liquid phase state and cooling the heat conductive member 27. You may adopt the one that became a phase.
Further, in the second embodiment, the transparent member 26 has a quadrangular pyramid shape, the heat storage member 23 has an inner surface inclined corresponding to the side surface of the transparent member 26, and the heat conductive member 27 has a substantially constant thickness. The structure having is illustrated. However, the present invention is not limited to this, and the shape of each part is arbitrary. For example, as shown in FIG. 9, the heat storage member 23 and the transparent member 26 are oriented so that the gap between them expands as the distance from the display surface 21a of the display member 21 increases so that the heat conductive grease or the like can be easily injected. It may have a gradient. In addition, any shape may be used as long as a gap is formed between the heat storage member 23 and the transparent member 26 that can absorb thermal expansion or absorption of manufacturing errors and does not block the indicator light L.

When a manufacturing method of injecting heat conductive grease or the like is adopted, when the heat conductive grease or the like is injected into the gap between the heat storage member 23 and the transparent member 26 in a normal pressure environment, air remains inside and thermal resistance is increased. May increase. Therefore, as illustrated in FIG. 10, it is desirable to form a groove portion 23a extending from the inner side surface to the outer surface of the heat storage member 23 in a part of the portion of the heat storage member 23 facing the display surface 21a.

By having such a configuration of the heat storage member 23, as shown in the XI-XI cross section of FIG. 3, a gap is formed between the heat storage member 23 and the display member 21, and the heat conductive grease is formed. It is possible to prevent the generation of residual air when such as is injected.

When the heat conductive member 27 is a curable type and is a material that is cured by a chemical reaction, when a transparent adhesive or the like comes into contact with the heat conductive member 27, the chemical reaction does not occur and curing inhibition may occur. Therefore, it is desirable that the transparent adhesive layer 28 is made of a sheet material smaller than the bottom surface of the transparent member 26 so as not to come into contact with the heat conductive member 27.

In order to position the heat storage member 23, a part of the inner side surface of the heat storage member 23 may protrude and come into contact with the side surface of the transparent member 26 (not shown).

(Third Embodiment)
In the above embodiment, the heat storage member 23 is arranged independently, but it can also function as a pedestal for arranging other members.

For example, as illustrated in FIG. 12, an arbitrary optical member 29 may be arranged in the optical path of the display light L with the heat storage member 23 as a support base. The optical member 29 is a member for reducing the temperature rise of the display member 21 by shielding the light rays that are incident from the outside and raise the temperature of the display member 21. For example, a hot mirror, a bandpass filter, a wire grid polarizing plate, or the like can be adopted.
The heat storage member 23 has, for example, a structure (not shown) such as a hook for fixing a cover (not shown), and the cover and the heat storage member 23 sandwich and hold the optical member 29.

According to this configuration, since the optical member 29 blocks external light, the temperature rise due to sunlight is suppressed as compared with the first embodiment. Further, since the heat storage member 23 has a mechanism for holding an auxiliary optical member such as a hot mirror, it is not necessary to separately provide a holding mechanism, and the assembly process can be simplified.

The invention of the present application is not limited to the above embodiment, and can be appropriately modified.
The first to third embodiments may be combined as appropriate. For example, a HUD device including both the transparent member of the second embodiment and the optical member of the third embodiment can be considered.

In the above embodiment, the display member 21 is a liquid crystal panel, but it may be an organic EL (Organic Electroluminescence) panel. In this case, the light source unit 30 is omitted.

In the above embodiment, the display device according to the present invention is applied to a HUD device for a vehicle, but the display device may be applied not only to a vehicle but also to a HUD device mounted on a vehicle such as an airplane or a ship. Further, although the display light L from the HUD device is projected on the windshield 3, it may be projected on the combiner. Further, the display device according to the present invention may be applied to a display device such as a projector used indoors or outdoors instead of the HUD device.

1 ... HUD device 2 ... Vehicle 3 ... Windshield 4 ... Viewer 10 ... Housing 11 ... Opening 12 ... Translucent cover 20 ... Display unit 21 ... Display member 21a ... Display surface 22 ... Frame 23 ... Heat storage member 24 ... Thermally conductive adhesive layer 25 ... Adhesive layer 26 ... Transparent member 27 ... Thermal conductive member 28 ... Transparent adhesive layer 29 ... Optical member 30 ... Light source unit 60 ... Plane mirror 70 ... Concave mirror

Claims (9)

A display member including a display surface that emits display light corresponding to an image,
A heat storage member having thermal conductivity arranged at a position on the display surface of the display member so as not to block the display light,
An adhesive layer having thermal conductivity provided between the display member and the heat storage member,
Equipped with a,
The heat storage member has a frame-like shape along the outer peripheral edge of the display member and has a frame-like shape.
A display device characterized in that the inner surface of the heat storage member has a gradient in a direction in which the cross-sectional area of the heat storage member is reduced toward the display surface of the display member. An optical relay that guides the display light from the display member to the projection member is provided.
The heat storage member has a heat capacity that prevents the temperature of the display member from reaching the reference temperature within a reference time when the display member is heated by external light composed of sunlight tracing through the optical relay. ,
The reference time is set to the time required for the focal point formed by the external light to pass through the display member.
The reference temperature is set to a heat-resistant temperature at which an abnormality may occur in the display device.
The display device according to claim 1. A transparent member arranged on the display surface of the display member.
The display device according to claim 1 or 2, wherein the display device is characterized by the above. The in-plane thermal resistance of the display member including the transparent member is equal to or less than the in-plane thermal resistance of the display member on which the transparent member is not arranged.
The display device according to claim 3, wherein the display device is characterized by the above. A flexible heat conductive member is provided between the heat storage member and the transparent member.
The display device according to claim 3 or 4. The transparent member is located surrounded by the heat storage member.
The inner surface of the heat storage member and the side surface of the transparent member face each other.
The display device according to claim 5. The side surface of the transparent member has a gradient in a direction in which the cross-sectional area of the transparent member expands toward the display surface of the display member.
The display device according to claim 6, wherein the display device is characterized by the above. The heat storage member has a groove extending from the inner side surface to the outer surface of the heat storage member in a part of the portion of the display member facing the display surface.
The display device according to any one of claims 5 to 7 , wherein the display device is characterized by the above. An optical member for reducing the temperature rise of the display member by shielding a light beam incident from the outside and raising the temperature of the display member is provided.
The heat storage member has a mechanism for holding the optical member.
The display device according to any one of claims 1 to 8 , wherein the display device is characterized by the above.

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