JP6412795B2 - Display device - Google Patents

Description

  The present invention relates to a display device.

  As a conventional display device mounted on a vehicle or the like, for example, Patent Document 1 discloses a display device including a first display unit that displays a vehicle instrument and a second display unit that displays additional information. ing. In the second display unit of the display device, a plurality of colorless and transparent light guide plates are arranged on the front side of the scale plate of the first display unit, and a pattern is formed on the light guide plate by a groove.

JP 2012-32286 A

  By the way, in the display device described in Patent Document 1, for example, when the groove formed in the light guide plate is made fine, the amount of light reflected by the fine groove is relatively reduced, and the pattern formed by the groove. There is a possibility that the symbol is difficult to visually recognize due to insufficient luminance.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a display device capable of ensuring appropriate visibility.

  In order to achieve the above object, a display device according to the present invention includes a first display surface that displays an image relating to vehicle information, and an uneven portion that is provided on the first display surface so as to transmit light and to form a pattern. A second display surface that is switchable between a display state in which the symbol is displayed by light emitted from a light source and a non-display state in which the symbol is not displayed by turning off the light source; Provided on an end surface of a member constituting the second display surface, which is an end surface opposite to the incident end surface on which light from the light source is incident, and in the irradiation direction of the light, and reflects the light from the light source to the uneven portion side. And a reflective material.

  Moreover, in the said display apparatus, the said uneven | corrugated | grooved part shall be a groove | channel formed in the surface of the member which comprises the said 2nd display surface.

  In the display device, the first display surface displays the image by light polarized in one direction, and the groove extends in a direction crossing the polarization direction of the deflected light. can do.

  The display device according to the present invention displays a combination of an image relating to vehicle information displayed on the first display surface and a symbol displayed on the second display surface that is provided on the first display surface and transmits light. It can be carried out. In this case, the display device displays the symbol on the second display surface by reflecting the light emitted from the light source to the incident end surface of the member configuring the second display surface by the uneven portion configuring the symbol. At this time, the display device reflects the light from the light source to the uneven portion side by the reflecting material provided on the incident end surface of the member constituting the second display surface and the end surface facing the light irradiation direction, The amount of light reflected by the uneven portion can be relatively increased. As a result, the display device can suppress the brightness of the symbol formed by the concavo-convex portion from being insufficient, and can prevent the symbol from becoming difficult to visually recognize, thereby ensuring appropriate visibility. There is an effect that can be.

FIG. 1 is an exploded perspective view illustrating a schematic configuration of a display device according to an embodiment. FIG. 2 is a schematic perspective view illustrating a schematic configuration of the superimposed display device of the display device according to the embodiment. 3 is a schematic cross-sectional view taken along line AA in FIG. FIG. 4 is a partial cross-sectional view taken along a surrounding line B in FIG. FIG. 5 is a schematic diagram for explaining the preconditions for the luminance measurement test of the display device. FIG. 6 is a schematic diagram for explaining the preconditions for the luminance measurement test of the display device. FIG. 7 is a schematic diagram for explaining the preconditions for the luminance measurement test of the display device. FIG. 8 is a diagram showing the result of the brightness measurement test of the display device. FIG. 9 is a schematic cross-sectional view along the depth direction of the superimposed display device of the display device according to the embodiment. FIG. 10 is a perspective view illustrating an optical simulation model for the transparent light guide plate of the display device according to the embodiment. FIG. 11 is a diagram illustrating an optical simulation result for the transparent light guide plate of the display device according to the embodiment.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[Embodiment]
FIG. 1 is an exploded perspective view illustrating a schematic configuration of a display device according to an embodiment. FIG. 2 is a schematic perspective view illustrating a schematic configuration of the superimposed display device of the display device according to the embodiment. 3 is a schematic cross-sectional view taken along line AA in FIG. FIG. 4 is a partial cross-sectional view taken along a surrounding line B in FIG. 5, FIG. 6, and FIG. 7 are schematic diagrams for explaining the preconditions for the luminance measurement test of the display device. FIG. 8 is a diagram showing the result of the brightness measurement test of the display device. FIG. 9 is a schematic cross-sectional view along the depth direction of the superimposed display device of the display device according to the embodiment. FIG. 10 is a perspective view illustrating an optical simulation model for the transparent light guide plate of the display device according to the embodiment. FIG. 11 is a diagram illustrating an optical simulation result for the transparent light guide plate of the display device according to the embodiment.

  As shown in FIG. 1, the display device 1 according to the present embodiment constitutes a so-called meter. For example, the display device 1 is mounted on an instrument panel provided on a dashboard of a vehicle such as an automobile and is used for driving the vehicle. Displays various information provided. Note that the width direction of the display device 1 shown in FIG. 1 typically corresponds to the vehicle width direction of a vehicle to which the display device 1 is applied. In the width direction of the display device 1, one side (front side in FIG. 1) toward the front surface of the display device 1 corresponds to the driver's seat side of the vehicle, and the other side (FIG. 1) toward the front surface of the display device 1. The rear side (inward) corresponds to the passenger seat side of the vehicle, but this may be reversed. Further, the depth direction of the display device 1 shown in FIG. 1 typically corresponds to the front-rear direction of the vehicle to which the display device 1 is applied (in other words, the vehicle traveling direction). Further, the front side of the display device 1 is the side facing the driver's seat of the vehicle, and is typically the side visually recognized by the driver sitting in the driver's seat. On the other hand, the back side of the display device 1 is the side opposite to the front side in the depth direction, and is typically the side accommodated inside the instrument panel.

  Specifically, the display device 1 includes a housing 2, a display 3 as an image display device, a dial plate 4, a superimposed display device 5, and a facing plate 6. The display device 1 has a structure in which a casing 2, a display 3, a dial 4, a superimposed display device 5, and a facing plate 6 are stacked in this order from the back side in the depth direction to the front side.

  The housing 2 constitutes a case in which various parts constituting the display device 1 are assembled and accommodated.

  The display 3 is driven and controlled via a control device or the like, and displays various images on the image display surface 3a. For example, a thin liquid crystal display can be used as the display 3, but not limited thereto, a plasma display, an organic EL display, or the like can also be used. As an image displayed on the image display surface 3a, for example, in addition to information related to the speed of the vehicle, eco-driving, etc., the accumulated travel distance, the cooling water temperature, the output rotational speed of the power source for travel, the remaining amount of fuel, the amount of battery storage In addition, driving information regarding various driving that changes every moment when driving the vehicle may be included.

  The dial 4 is a plate-like member on which various warning lights (warning lamps, so-called telltales), shift position indicators, direction indication symbols, and the like are drawn. The dial 4 is irradiated with light from the back side, and the irradiated light is transmitted through the portion where the symbols, characters, graphics, etc. are drawn, so that the symbols, characters, graphics, etc. are lit and displayed.

  In the display 3 described above, the front surface is exposed from the dial 4, and the front surface of the display 3 constitutes the image display surface 3 a. The said image display surface 3a comprises the 1st display surface 51 which displays the real image image (image) 51a regarding vehicle information. Here, the vehicle information includes driving information relating to the above-described various driving operations such as the vehicle state and traveling state of the vehicle on which the display device 1 is mounted, and the first display surface 51 displays these information as a real image 51a. To the driver. The first display surface 51 is in a state in which the real image 51a can be displayed in the on state, and the real image 51a is not displayed in the off state.

  As shown in FIGS. 1, 2, 3, and 4, the superimposed display device 5 includes a transparent light guide plate 5a and a light source 5b. The transparent light guide plate 5a is provided so as to overlap the front side of the image display surface 3a. The transparent light guide plate 5a is formed by a transparent member (transparent medium) having transparency that transmits light emitted from the display 3. The transparent light guide plate 5a is formed with fine grooves 5d constituting a design (display design) 5c. The groove 5d constituting the pattern 5c is formed on the main surface of the transparent light guide plate 5a by, for example, molding the transparent light guide plate 5a using a mold having a convex shape corresponding to the groove 5d. You may form so that it may become a concave shape on the main surface by the side of the back surface of the said transparent light-guide plate 5a. Further, the grooves 5d constituting the pattern 5c are formed on the main surface of the transparent light guide plate 5a, here, on the main surface on the back side of the transparent light guide plate 5a by digging by various methods such as laser processing, for example. You may form so that it may become a concave shape. The symbols 5c formed by the grooves 5d on the transparent light guide plate 5a may include, for example, various symbols related to driving information displayed on the display 3. In the example of FIG. 1, the symbol 5c is, for example, “a vehicle symbol (icon) imitating a vehicle”. In the example of FIG. 2, the symbol 5c is, for example, the numeral “2”, but is not limited thereto. Absent. The light source 5b irradiates light to the end surface of the transparent light guide plate 5a. The light source 5b is constituted by, for example, an LED (Light Emitting Diode) element or the like, but is not limited thereto. The light source 5b is provided such that the optical axis direction thereof is orthogonal to the end surface of the transparent light guide plate 5a, and the irradiated light is incident from the end surface of the transparent light guide plate 5a. The extending direction of the groove 5d, the light irradiation direction by the light source 5b, and the like will be described in detail later.

  In the superimposed display device 5, when the light source 5 b is driven and controlled via a control device or the like, display or non-display of the symbol 5 c is switched based on whether the light source 5 b is turned on or off. When the light source 5b is turned on, the superimposed display device 5 is in a state where the pattern 5c is displayed. That is, the light emitted from the light source 5b is incident on the end surface of the transparent light guide plate 5a and propagates through the transparent light guide plate 5a. At least a part of the component of the incident light is reflected to the front side by the groove 5d constituting the symbol 5c, and as a result, the driver or the like can visually recognize the symbol 5c (see FIGS. 3 and 4). . In this case, the superimposed display device 5 displays a pattern 5c displayed on the transparent light guide plate 5a when the driver views from the front side (driver's seat side) on the back side of the transparent light guide plate 5a. A predetermined design can be formed by superimposing on the image on the third image display surface 3a, thereby enabling various displays. On the other hand, in the superimposed display device 5, when the light source 5b is turned off, the pattern 5c is not displayed, and the driver or the like is displayed on the image display surface 3a by the light emitted from the display 3 and transmitted through the transparent light guide plate 5a. It will be in the state which is easy to visually recognize the image of.

  The main surface on the back side of the transparent light guide plate 5a in which the grooves 5d are formed as described above is provided so as to overlap the first display surface 51 and transmits light, and the first display surface 51 can display the real image 51a. The second display surface 52 that can be switched between the display state and the non-display state in the ON state is configured. Here, the display state of the second display surface 52 is a state in which the real image symbol 52a is displayed by the light emitted from the light source 5b. The real image pattern 52a is the above-described pattern 5c, and is, for example, the above-described “vehicle body symbol (icon) imitating a vehicle”, that is, a vehicle symbol or the like. On the other hand, the non-display state of the second display surface 52 is a state in which the real image pattern 52a is not displayed when the light source 5b is turned off.

  The first display surface 51 and the second display surface 52 described above constitute a plurality of display surfaces that are overlapped in the depth direction, in other words, the vehicle traveling direction, and the first display surface 51 corresponds to the plurality of display surfaces. A display surface on the far side in the vehicle traveling direction is configured, and the second display surface 52 configures a display surface on the front side in the vehicle traveling direction of the plurality of display surfaces (the viewing position side of a viewer such as a driver).

  The facing plate 6 is a frame-shaped member that surrounds the dial plate 4, the transparent light guide plate 5 a, etc., and presses the dial plate 4, the transparent light guide plate 5 a, etc.

  And the display apparatus 1 of this embodiment is comprised so that the polarization direction of the display 3 and the extending direction of the groove | channel 5d which comprises the pattern 5c may cross | intersect within a predetermined angle range, and display 3 and a superimposition display apparatus In addition to realizing various displays in combination with 5, it is possible to ensure proper visibility. Here, the polarization direction of the display 3 typically corresponds to the final transmission axis direction in the display 3, and the extending direction of the groove 5d is typically the direction in which the groove 5d extends. Equivalent to.

  The display 3 of this embodiment is configured to display an image by irradiating light polarized in one direction. That is, in the display 3, the light emitted from the backlight is aligned with the polarization direction L1 (see FIG. 2 etc.) as the transmission axis direction via the polarizing plate or the like, and along the polarization direction L1 (transmission axis direction). By emitting light in the vibration direction, light polarized in one direction is emitted. In the display 3, typically, the front surface of the final polarizing plate constitutes the surface of the above-described image display surface 3a, the transparent light guide plate 5a is disposed on the front side of the polarizing plate, and the polarization direction L1 (transmission) The light in the vibration direction along the (axial direction) enters the transparent light guide plate 5a. Here, the polarization direction L1 is a direction along the vertical direction. Hereinafter, the final polarization direction of the display 3 may be referred to as “polarization direction L1”.

  On the other hand, the plurality of fine grooves 5d constituting the design (display design) 5c have, for example, a substantially V-shaped cross-sectional shape as shown in FIG. 4 and the like, and the pitch is 1 μm or less (the lower limit value can be manufactured, for example) Preferably). Each groove 5d is formed as a linear groove extending in one direction. Further, the transparent light guide plate 5a is configured so that the transmittance of the material in the region of the symbol 5c is equal to the transmittance of the material in the region around the symbol 5c in the transparent light guide plate 5a. In the diffraction grating constituted by such a fine groove 5d, the vibration direction of light is perpendicular (orthogonal) to the extending direction of the groove 5d (see the arrow L2 in FIG. 2) and parallel to the case. The diffraction efficiency tends to be different from that in some cases. That is, the diffraction grating constituted by such a fine groove 5d typically transmits light whose vibration direction is perpendicular to the extending direction L2 of the groove 5d, while the vibration direction is that of the groove 5d. There is a tendency to block light that is parallel to the extending direction L2. That is, the minute groove 5d formed on the transparent light guide plate 5a exhibits an action similar to that of the polarizing plate, and the direction perpendicular to the extending direction L2 of the groove 5d is a transmission axis direction and vibrates in the transmission axis direction. While transmitting light, most of the light vibrating in the absorption axis direction (extending direction L2 of the groove 5d) orthogonal to the transmission axis direction is blocked.

  And the display apparatus 1 of this embodiment is comprised so that the polarization direction L1 of the display 3 and the extending direction L2 of the groove | channel 5d which comprises the pattern 5c may cross | intersect in the angle range of 75 degrees or more and 105 degrees or less. When the angle formed by the polarization direction (transmission axis direction) L1 of the display 3 and the extending direction L2 of the groove 5d constituting the pattern 5c is an angle θ (see FIG. 2), the angle θ of the groove 5d is [75 °. ≦ θ ≦ 105 °] is formed on the transparent light guide plate 5a so as to satisfy the conditional expression. That is, the polarization direction L1 and the extending direction L2 intersect with each other with a predetermined angle θ within a range of 75 ° to 105 °. More preferably, the polarization direction L1 and the extending direction L2 intersect with each other with a predetermined angle θ within a range of 85 ° to 95 °. Most preferably, the polarization direction L1 of the display 3 is orthogonal to the extending direction L2 of the groove 5d constituting the pattern 5c. Here, in the groove 5d, the extending direction L2 of the groove 5d is orthogonal to the polarization direction L1 of the display 3, and the transmission axis direction of the diffraction grating constituted by the fine groove 5d is parallel to the polarization direction L1. It is formed on the transparent light guide plate 5a. In addition, when the polarization direction L1 of the display 3 and the extending direction L2 of the groove 5d are orthogonal, in addition to the case of θ = 90 °, for example, an allowable error corresponding to a tolerance allowed in manufacturing the display device 1 Errors within the range of the angle α are allowed.

  The display device 1 configured as described above is configured such that the polarization direction L1 of the display 3 and the extending direction L2 of the groove 5d are orthogonal to each other (θ = 90 °), in other words, the polarization direction L1 of the display 3. And the transmission axis direction of the groove 5d are configured to be parallel to each other. As a result, the display device 1 transmits almost all light from the display 3 in the area inside the symbol 5c in the state where the light source 5b is turned off, as in the area outside the symbol 5c. As a result, in the non-display state in which the light source 5b is turned off, the display device 1 has a luminance ratio (hereinafter simply referred to as a ratio of the luminance of the region of the symbol 5c to the luminance of the region around the symbol 5c in the transparent light guide plate 5a. “The luminance ratio of the area of the pattern 5c with respect to the area around the pattern 5c”) is maximized. Therefore, the area of the pattern 5c is less conspicuous than the area around the pattern 5c, and the pattern 5c is visually recognized. Can be difficult. Here, the luminance ratio of the area of the symbol 5c to the area around the symbol 5c is typically represented by “luminance of the area of symbol 5c / luminance of the area around symbol 5c × 100 [%]”. In other words, the smaller the luminance ratio is, the larger the luminance difference between the area around the symbol 5c and the area of the symbol 5c is.

  The display device 1 is not limited to the state (θ = 90 °) in which the polarization direction L1 and the extending direction L2 are orthogonal to each other, but the above [75 ° ≦ θ ≦ 105 °], more preferably [85 ° ≦ θ. If it is within the range of ≦ 95 °, the luminance ratio of the area of the symbol 5c to the area around the symbol 5c falls within the predetermined luminance ratio range, so that the symbol 5c can be maintained in a state where it is difficult to visually recognize. Here, the predetermined luminance ratio range is, for example, a range of 90% to 100%, more preferably a range of 92.5% to 100%. As described above, the display device 1 is configured such that the polarization direction L1 of the display 3 and the extending direction L2 of the groove 5d intersect in the above-described angular range, so that the polarizing direction L1 and the extending direction are configured. L2 can be configured to intersect at an angle range in which the luminance ratio of the luminance of the pattern 5c region to the luminance of the region around the symbol 5c is 90% or more and 100% or less.

  Here, the brightness measurement test for the display device 1 will be described with reference to FIGS. Here, a luminance measurement test was performed in which the luminance of the transparent light guide plate 5a was measured with a luminance measurement camera using the display device 1 according to the embodiment described above. Here, in the display device 1, the display 3, the transparent light guide plate 5 a, and the like are arranged so as to have the arrangement shown in FIG. 5, and the grooves 5 d are formed so as to have the shape shown in FIG. 6. . That is, in the display device 1, the thickness of the transparent light guide plate 5 a in the depth direction is 2 mm, and the distance in the depth direction between the image display surface (front surface) 3 a of the display 3 and the back surface (back surface) of the transparent light guide plate 5 a is set. It was 4.5 mm. And in the said display apparatus 1, the groove | channel 5d which comprises the pattern 5c was formed in the back surface of the transparent light-guide plate 5a. The luminance measurement position with respect to the Z direction (depth direction) in this luminance measurement test is a position on the surface where the groove 5d of the transparent light guide plate 5a is formed, and corresponds to the focal position of the luminance measurement camera. And in the said display apparatus 1, the groove | channel 5d is formed in a substantially V-shaped cross-sectional shape and 0.5 micrometer pitch, the depth of the depth direction of each groove | channel 5d shall be 0.25 micrometer, and the angle which a bottom part makes is made. The angle was approximately 90 ° (deg). In the display device 1, each groove 5 d is formed as a linear groove extending in one direction. As shown in FIG. 7, a plurality of positions are selected for the luminance measurement positions in the X direction (width direction) and the Y direction (vertical direction) in the luminance measurement test in the area of the pattern 5c and the area around the pattern 5c. These average values were used. The lighting conditions of the light source color of the display 3 include red light with X = 0.63 and Y = 0.35 in the chromaticity diagram, green light with X = 0.31 and Y = 0.58, X = 0.14, Y = 0.05 was used, and the brightness | luminance measurement test was implemented, respectively. In this luminance measurement test, the above-described luminance is obtained by changing the angle θ between the polarization direction L1 and the extending direction L2 by rotating the transparent light guide plate 5a relative to the image display surface 3a with the light source 5b turned off. The luminance was measured at the measurement position using a luminance measurement camera.

  FIG. 8 shows the result of the luminance measurement test. In FIG. 8, the horizontal axis represents the angle θ [deg] formed by the polarization direction L1 and the extending direction L2, and the vertical axis represents the luminance ratio [%] of the luminance of the region of the symbol 5c to the luminance of the region around the symbol 5c. Yes. As is apparent from FIG. 8, the display device 1 is red (see the line R) when the angle θ formed by the polarization direction L1 and the extending direction L2 is within the range of [75 ° ≦ θ ≦ 105 °]. In all three colors, green (see line G) and blue (see line B), the luminance ratio of the pattern 5c area to the surrounding area of the pattern 5c is 90% to 100%, and the pattern 5c is not displayed. In this case, it is clear that the grooves 5d constituting the symbols 5c on the transparent light guide plate 5a can be made difficult to be visually recognized. Furthermore, when the angle θ is within the range of [85 ° ≦ θ ≦ 95 °], the display device 1 can display the region of the symbol 5c with respect to the region around the symbol 5c in all three colors of red, green, and blue. It is apparent that the luminance ratio is 92.5% or more and 100% or less, and the groove 5d can be further hardly seen. When the angle θ is [θ = 90 °], that is, when the polarization direction L1 and the extending direction L2 are orthogonal to each other, the display device 1 displays the pattern 5c in all three colors of red, green, and blue. It is clear that the luminance ratio of the area of the pattern 5c with respect to the area around is maximized, and the groove 5d can be most hardly visually recognized. Here, when the angle θ is [θ = 90 °], the display device 1 has a luminance ratio of 97.4% when irradiated with red light and a luminance ratio of 97. 9 when irradiated with green light. The luminance ratio when irradiated with 6% blue light was 94%.

  Further, as shown in FIG. 2 and the like, the display device 1 of the present embodiment is configured such that the extending direction L2 of the groove 5d and the light irradiation direction L3 by the light source 5b of the superimposed display device 5 are orthogonal to each other. The That is, here, the polarization direction L1 of the display 3 and the light irradiation direction L3 by the light source 5b are directions along the vertical direction, and the extending direction L2 of the groove 5d is a direction along the horizontal direction. Therefore, the display device 1 can make the light from the light source 5b incident substantially perpendicularly to the grooves 5d constituting the design 5c, so that the design 5c is displayed on the transparent light guide plate 5a. The amount of light reflected to the front side (driver's seat side) by the groove 5d can be relatively increased, and the symbol 5c can be clearly displayed. The transparent light guide plate 5a of the present embodiment is formed such that the horizontal length is longer than the vertical length, and the light source 5b is disposed on the lower side in the vertical direction or the upper side in the vertical direction of the transparent light guide plate 5a. The light source 5b of the present embodiment is located along the width direction (horizontal direction), etc., at a position on the lower side in the vertical direction of the region where the pattern 5c is formed and facing the end surface on the lower side in the vertical direction of the transparent light guide plate 5a. Three are provided at intervals, and irradiates light upward in the vertical direction. Each light source 5b is arrange | positioned in the position concealed by the facing plate 6 seeing from the front side, for example.

  As shown in FIGS. 3 and 4, the second display surface 52 has a positional relationship such as the polarization direction L <b> 1, the extending direction L <b> 2, the irradiation direction L <b> 3, etc. A plurality of fine grooves 5d are formed so that the display structure 53 and the non-display structure 54 of the real image design 52a (the design 5c) are configured.

  Here, the display structure 53 of the second display surface 52 is a structure for forming the real image symbol 52a (the symbol 5c) by the light emitted from the light source 5b in the display state of the second display surface 52. Here, the display structure 53 has unevenness formed on the surface of the transparent light guide plate 5a, which is a member constituting the second display surface 52, with the light emitted from the light source 5b in the display state of the second display surface 52. This is a structure in which the real image pattern 52a is formed by being reflected by a plurality of fine grooves 5d as a portion. Thereby, the display structure 53 can make the driver | operator etc. the state which can visually recognize the real image design 52a on the 2nd display surface 52. FIG.

  On the other hand, the non-display structure 54 of the second display surface 52 is a structure for making it difficult to visually recognize the real image pattern 52a as compared with the display state in the non-display state of the second display surface 52. Furthermore, the non-display structure 54 of the second display surface 52 is difficult to visually recognize the plurality of fine grooves 5d as the uneven portions in the non-display state of the second display surface 52 compared to the display state. It is a structure to do. Here, the non-display structure 54 makes it difficult to visually recognize the real image pattern 52a by turning off the light source 5b, and further, the polarization direction L1 of the display 3 and the extension of the groove 5d constituting the real image pattern 52a (the pattern 5c). By forming the groove 5d so as to intersect the existing direction L2 within a predetermined angle range, typically, an angle range of 75 ° to 105 ° as described above, the groove 5d itself is also difficult to visually recognize. Structure. As a result, the non-display structure 54 is configured so that the amplitude of the transmitted light is substantially the same in the real image pattern 52a area on the second display surface 52 and the area around the real image pattern 52a. It is possible to achieve a state in which there is almost no difference in luminance from the surrounding area of the pattern 52a. Thereby, in the non-display state, the real image pattern 52a and a plurality of fine grooves 5d as the concavo-convex portions constituting the real image pattern 52a. Can be difficult to see.

  Here, in the display device 1 described above, in order to make it difficult to visually recognize the real image symbol 52a by the non-display structure 54 in the non-display state of the second display surface 52, a plurality of fine images constituting the real image symbol 52a are included. It is preferable to make the pitch of the grooves 5d smaller. For example, as described above, it is preferable to set the pitch to 1 μm or less. On the other hand, when the display device 1 reduces the pitch of the plurality of fine grooves 5d constituting the real image pattern 52a, the amount of light reflected by the fine grooves 5d by the display structure 53 in the display state of the second display surface 52 is relatively high. The actual image pattern 52a formed by the groove 5d is insufficient in luminance, and the real image pattern 52a may be difficult to visually recognize.

  Therefore, in the display device 1 of the present embodiment, as shown in FIGS. 1 and 9, the reflective material 55 is provided at a predetermined portion of the end surface of the transparent light guide plate 5 a that is a member constituting the second display surface 52. Therefore, proper visibility is ensured.

  Specifically, the reflective material 55 is provided on an end surface of the transparent light guide plate 5a constituting the second display surface 52, which is opposite to the incident end surface on which light from the light source 5b is incident, and in the irradiation direction of the light. . Here, the reflective material 55 is provided on the end surface on the upper side in the vertical direction of the transparent light guide plate 5a and facing the light source 5b in the vertical direction. The reflective material 55 reflects the light from the light source 5b toward the groove 5d as an uneven portion. The reflective material 55 is made of, for example, a hot stamp foil, a mirror foil, or the like, but is not limited thereto, and any material that reflects light from the light source 5b toward the groove 5d may be used.

  According to the display device 1 described above, the first display surface 51 that displays the real image 51a relating to the vehicle information, the light that is provided so as to overlap the first display surface 51 and transmits the real image 52a (symbol 5c). A display state in which the concavo-convex portion (groove 5d) to be formed is formed and the real image symbol 52a is displayed by light emitted from the light source 5b, and a non-display state in which the real image symbol 52a is not displayed by turning off the light source 5b The switchable second display surface 52 and the end surface of the transparent light guide plate 5a, which is a member constituting the second display surface 52, are opposed to the incident end surface on which light from the light source 5b is incident, in the irradiation direction of the light. And a reflecting material 55 provided on the end face and reflecting the light from the light source 5b toward the concavo-convex portion (groove 5d).

  Accordingly, the display device 1 includes a real image 51a on the vehicle information displayed on the first display surface 51 and a real image pattern 52a displayed on the second display surface 52 that is provided on the first display surface 51 and transmits light. Can be displayed in combination. In this case, the display device 1 reflects the light emitted from the light source 5b to the incident end face of the transparent light guide plate 5a that constitutes the second display surface 52 by the uneven portion (groove 5d) that constitutes the real image pattern 52a. The real image symbol 52 a is displayed on the second display surface 52. At this time, the display device 1 reflects light from the light source 5b toward the concave and convex portion (groove 5d) by the reflecting material 55 provided on the incident end surface of the transparent light guide plate 5a and the end surface facing the light irradiation direction. Thus, the amount of light reflected by the uneven portion (groove 5d) can be relatively increased. As a result, the display device 1 can suppress the luminance of the real image symbol 52a formed by the uneven portion (groove 5d) from being insufficient, and can suppress the real image symbol 52a from becoming difficult to visually recognize. Appropriate visibility can be ensured. Particularly, since the display device 1 is configured to display the real image 51a on the first display surface 51 on the back side of the second display surface 52, the real image symbol 52a displayed on the second display surface 52 is difficult to see. Although there is a tendency, by providing the reflective material 55 as described above, the amount of light reflected by the concavo-convex portion (groove 5d) in the display state of the second display surface 52 can be relatively increased. Even if it is a structure, appropriate visibility can be ensured. Moreover, since the display apparatus 1 can also suppress the luminance unevenness of the real image pattern 52a by the action of the reflecting material 55, it is possible to ensure appropriate visibility also in this respect.

FIG. 11 shows the result of the optical simulation in the CC cross section shown in FIG. 10, where the horizontal axis indicates the position in the cross-sectional direction of the transparent light guide plate 5a (in this case, the irradiation direction L3), and the vertical axis indicates the luminance [cd / m ² ]. In FIG. 11, a line L101 represents a luminance distribution when the reflecting material 55 is not provided, and a line L102 represents a luminance distribution when the reflecting material 55 is provided. As is clear from FIG. 11, when the reflecting material 55 is not provided, the brightness drop on the side away from the light source 5b is relatively large, whereas when the reflecting material 55 is provided, the side away from the light source 5b. The drop in brightness is relatively small. That is, it is clear that the display device 1 of the present embodiment provided with the reflective material 55 can improve the luminance on the side away from the light source 5b that tends to be dark, and can improve luminance unevenness.

  Furthermore, according to the display device 1 described above, the concave and convex portions constituting the real image symbol 52a (the symbol 5c) are grooves 5d formed on the surface of the transparent light guide plate 5a which is a member constituting the second display surface 52. It is. Therefore, the display device 1 reflects the light emitted from the light source 5b in the display state of the second display surface 52 by the grooves 5d as the uneven portions formed on the surface of the transparent light guide plate 5a. 52a can be formed. At this time, the display device 1 includes the reflector 55 as described above, so that the amount of light reflected by the groove 5d constituting the real image pattern 52a can be relatively increased, and appropriate visibility can be ensured. Can do.

  Furthermore, according to the display device 1 described above, the first display surface 51 displays the real image 51a with light polarized in one direction, and the groove 5d intersects the polarization direction L1 of the deflected light. Extend in the direction. Here, the polarization direction L1 of the display 3 and the extending direction L2 of the groove 5d intersect in the above-described angle range. Therefore, the display device 1 can display the design of the design 5c on the front side of the image display surface 3a of the display 3, and can display the image information on the background image display surface 3a and the design of the design 5c in a three-dimensional combination. Therefore, for example, a stereoscopic and novel display can be performed. In addition, in the display device 1, the design of the design 5 c becomes difficult to see when the light source 5 b is turned off in the superimposed display device 5 in which the design 5 c is configured by the fine grooves 5 d, and the background image display surface of the transparent light guide plate 5 a is displayed. 3a can be seen, and the design of the pattern 5c can appear when the light source 5b is turned on as necessary.

  The display device according to the above-described embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the claims.

  In the above description, the display 3 has been described as being configured by one, but may be configured by combining two or more. In the display device 1 described above, for example, the polarization direction L1 of the display 3 may be inclined with respect to the vertical direction. Even in this case, the polarization direction L1 and the extending direction L2 are as described above. It only has to be a relationship.

  In the above description, the light source 5b is located along the width direction (horizontal direction) at a position on the lower side in the vertical direction of the region where the pattern 5c is formed and facing the lower end surface of the transparent light guide plate 5a in the vertical direction. Although it has been described that three are provided at intervals and irradiate light toward the upper side in the vertical direction, the present invention is not limited thereto, and may be provided on the upper side in the vertical direction of the transparent light guide plate 5a, or the width of the transparent light guide plate 5a. It may be provided in the direction side. And the reflective material 55 should just be formed in the position facing the said light source 5b with respect to the irradiation direction L3 of the light from the light source 5b in the end surface on the opposite side to the light source 5b of the transparent light-guide plate 5a.

  In FIG. 6 described above, the groove 5d has been described as having a substantially V-shaped cross-sectional shape forming a right isosceles triangle with a bottom angle of approximately 90 ° (deg), but is not limited thereto. For example, the groove 5d may not have a bottom angle of 90 ° (deg), or may have a substantially V-shaped cross-sectional shape that is not an isosceles triangle. Further, in the above description, the display structure 53 has been described as a structure that forms the real image pattern 52a by being reflected by the plurality of fine grooves 5d as the uneven portions formed on the surface of the transparent light guide plate 5a. However, the present invention is not limited to this, and the uneven portion for reflecting light may be a light reflecting structure such as a plurality of fine dots or a printing layer having a plurality of fine unevenness.

DESCRIPTION OF SYMBOLS 1 Display apparatus 3 Display 5 Superimposition display apparatus 5a Transparent light-guide plate 5b Light source 5c Pattern 5d Groove (uneven part)
51 First display surface 51a Real image (image)
52 2nd display surface 52a Real image design (design)
55 Reflector L1 Polarization direction L2 Extension direction L3 Irradiation direction

Claims (3)

A first display surface for displaying an image relating to vehicle information;
A display state in which a concavo-convex portion that is provided to overlap the first display surface and transmits light and constitutes a symbol is formed, and the symbol is displayed by light emitted from a light source, and the symbol is turned off when the light source is turned off. A second display surface that can be switched between a non-display state and a non-display state;
Provided on an end surface of a member constituting the second display surface, which is an end surface opposite to an incident end surface on which light from the light source is incident, and in an irradiation direction of the light, and reflects light from the light source toward the uneven portion side And a reflective material that
Display device. The concavo-convex portion is a groove formed on the surface of a member constituting the second display surface.
The display device according to claim 1. The first display surface displays the image by light polarized in one direction,
The groove extends in a direction intersecting a polarization direction of the deflected light;
The display device according to claim 2.

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