Display device

Abstract

To provide a display device which can prevent deterioration of luminance in a portion covering imaging means of a display panel.SOLUTION: A vehicular measuring instrument 1 includes: a display panel 2; a direct backlight 3 which is arranged with multiple light sources 16 and lights the display panel 2 from the back side; a flutter 5 which is provided between the display panel 2 and the backlight 3 and diffuses light emission of the light sources 16; and a camera 11 which captures images of a driver D with infrared light. In the flutter 5, a circular hole 20 is formed so as to avoid an arrangement position of the light sources 16 in a front view. The light beams emitted from the light sources 16 are guided to a peripheral surface 29 of the circular hole 20, and the camera 11 is arranged at a position facing the circular hole 20.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a display device that is suitably mounted on a vehicle such as an automobile or a motorcycle. [Background technology]

[0002] There has been known a display device that is mounted on vehicles such as automobiles and motorcycles to display vehicle information such as vehicle speed, and which has an integrated driver monitoring device that can capture images of the vehicle occupants by shining infrared light on them and detect the occupant's behavior such as looking away or falling asleep based on the captured images.

[0003] For example, the vehicle display device described in Patent Document 1 includes a display panel, a circuit board with a cutout located behind the display panel, a plurality of light sources provided on the circuit board, an infrared light irradiator arranged behind the display panel, an imaging means which constitutes a camera module together with the infrared light irradiator, and a housing with a partition wall that penetrates the cutout and surrounds the camera module, and the imaging means images the driver using infrared light that is irradiated by the infrared light irradiator to the driver of the vehicle and reflected by the driver. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 158602 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the vehicle display device described in Patent Document 1, the portion of the display panel covering the imaging means is inevitably dark (low brightness) because the light emitted by the light source is blocked by the partition wall, causing a problem in that the design of the display is compromised.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a display device capable of preventing a decrease in luminance in a portion of a display panel that covers an imaging means. [Means for solving the problem]

[0007] In order to solve the above problems, a display device according to the present invention includes a display panel, a direct-type backlight having a plurality of light sources arranged therein and illuminating the display panel from the rear side, a light control member provided between the display panel and the backlight and diffusing light emitted from the light sources, and an imaging means for imaging an image of an imaged person using infrared light, wherein a first through portion penetrating the light control member from the front side to the rear side is formed so as to avoid the positions of the light sources in a front view, and the light emitted from the light sources is guided to an inner wall surface of the first through portion, and the imaging means is disposed at a position facing the first through portion. The backlight includes a circuit board on which the plurality of light sources are arranged, and a third through-hole penetrating the circuit board from the front side to the rear side is formed at a position overlapping the first through-hole, and the plurality of light sources are arranged on the circuit board such that the arrangement intervals are narrower in the vicinity of the third through-hole than in other portions other than the vicinity of the third through-hole. It is characterized by:

[0010] A brightness enhancing member that increases the brightness of the light emitted by the light source is provided between the display panel and the light control member, and the brightness enhancing member may have a fourth through-hole that penetrates from the front side to the rear side at a position overlapping with the first through-hole, or a diffusion member that diffuses the light emitted by the light source and transmits the infrared light may be provided between the display panel and the light control member. Effect of the Invention

[0011] According to the present invention, it is possible to prevent a decrease in luminance in a portion of a display panel that covers the imaging means. [Brief description of the drawings]

[0012] [Figure 1] 1 is a front view of a vehicle instrument according to a first embodiment of the present invention; [Diagram 2] 2 is an explanatory diagram showing a cross section AA of the vehicle instrument in FIG. 1 and a driver. [Diagram 3]2 is a front view showing a central portion of a backlight and a camera of the vehicle instrument of FIG. 1. [Figure 4] 2 is a block diagram showing an electrical configuration of the vehicle instrument shown in FIG. 1; [Diagram 5] FIG. 11 is an explanatory diagram showing a vehicle instrument and a driver according to a second embodiment of the present invention. [Figure 6] FIG. 11 is a front view showing a central portion of a backlight and a camera of a vehicle instrument according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (First embodiment) 1 to 3, an example in which the display device of the present invention is applied to a vehicle instrument 1 mounted in front of the driver's seat of an automobile will be described below. In the following description, the side of a driver D who sits in the driver's seat and views the vehicle instrument 1 will be referred to as the front side of the vehicle instrument 1, and the opposite side will be referred to as the rear side.

[0014] The vehicle instrument 1 is mainly composed of a display panel 2 that displays various vehicle information, a direct-type backlight 3 that illuminates the display panel 2 from the back side, a cover glass 4 that covers the front side of the display panel 2, a flutter 5 provided between the display panel 2 and the backlight 3, a diffuser plate 6 and a diffuser plate 7 that are laminated on the back side and front side of the flutter 5, a BEF (Brightness Enhancement Film) 8 and a DBEF (Dual Brightness Enhancement Film: a reflective polarizing film for enhancing brightness) 9 that are provided in that order on the front side of the diffuser plate 7 between the display panel 2, a case member 10 that houses the display panel 2, the backlight 3, the flutter 5, the diffuser plate 6, the diffuser plate 7, the BEF 8 and the DBEF 9, a camera 11, and an infrared light irradiation unit 12.

[0015] The display panel 2 may be, for example, a known liquid crystal display panel in which polarizing plates are attached to the front and back surfaces of a liquid crystal cell in which liquid crystal is sealed between a pair of insulating substrates (glass substrates).

[0016] Moreover, the display panel 2 has a flat display surface 13 that can be viewed directly by the driver D, and various vehicle information is displayed on this display surface 13. Fig. 1 shows an example in which a vehicle speed display unit 14 that displays the vehicle speed as vehicle information is displayed on the display surface 13.

[0017] The backlight 3 includes a rectangular circuit board 15 located on the rear side of the display panel 2, and a plurality of light sources 16 (in FIG. 3, the light sources are denoted by reference characters 16a to 16h to distinguish between the individual light sources, and in FIG. 6 described later, the light sources are further denoted by reference characters 16i, 16j, 16k, and 16m) arranged regularly (in a matrix) on the circuit board 15 (on the front side of the board surface).

[0018] Circuit board 15 is, for example, a hard wiring board in which a wiring pattern is applied to a glass epoxy-based base material, and the wiring pattern is conductively connected to light source 16, control unit 17 (see FIG. 4) which controls the display of display panel 2 and the lighting of light source 16, as well as controls the operations of camera 11 and infrared light irradiation unit 12, and various circuit components such as resistors and capacitors. Circuit board 15 is electrically connected to display panel 2, camera 11, and infrared light irradiation unit 12 using flexible wiring (not shown).

[0019] At the center of the circuit board 15, circular holes 18 are formed between the light sources 16 so as to avoid the positions where the light sources 16 are disposed, i.e., between the light sources 16b, 16c, 16f, and 16g located near the center of the circuit board 15. Here, the circular hole 18 is provided at the center of the pitch in both the vertical and horizontal directions, since its center point O is located at the center of the pitch L of the light sources 16b and 16c (or the light sources 16f and 16g) and at the center of the pitch L of the light sources 16b and 16f (or the light sources 16c and 16g), and the light sources 16b, 16c, 16f, and 16g are located on a virtual circumference C1 of radius L / (√2) centered on the center point O near the circular hole 18, and the light sources 16a, 16d, 16e, and 16h are located on a virtual circumference C2 of radius (√10)L / 2 centered on the center point O.

[0020] The light source 16 is a light emitting body that emits visible light toward the front side, and a chip-type light emitting diode that emits light of an appropriate color can be used.

[0021] The cover glass 4 is a generally flat protective panel member formed of a light-transmitting synthetic resin material and provided so as to cover the front side of the display panel 2. A light-shielding portion 19 is formed on the periphery of the rear side of the cover glass 4. The light-shielding portion 19 is formed, for example, of a black printed layer that blocks visible light and transmits infrared light. The cover glass 4 may be bonded to the display panel 2 with a light-transmitting adhesive, and further, the outermost surface of the cover glass 4 on the front side may not be a flat surface but may be a curved shape (curved shape) that is convex toward the front side.

[0022] The flutter 5 has the same shape as the circuit board 15 when viewed from the front (when viewed from the front side), and a circular hole 20 of the same diameter as the circular hole 18 is formed at a position overlapping with the circular hole 18 in the center of the rectangle. The flutter 5 is a white plate with many fine holes drilled therein, and diffuses the incident light. The fine holes of the flutter 5 may be drilled in the same manner throughout the flutter 5, or may not be drilled around the light source 16, and may be drilled so that the diameter increases with distance from the light source 16.

[0023] The diffusion plates 6 and 7 are provided to further uniformize the diffusion of light by the flutter 5, and may be, for example, an optical film in which light-diffusing particles are dispersed in a light-transmitting resin film. Both of the diffusion plates 6 and 7 are rectangular like the flutter 5, and a circular hole 21 having the same diameter as the circular hole 20 is formed in the center of the diffusion plate 6, and a circular hole 22 having the same diameter as the circular hole 20 is formed in the center of the diffusion plate 7. The circular holes 21, 20, and 22 overlap in this order from the rear side to form an integrated circular hole.

[0024] BEF8 and DBEF9 improve the brightness of the incident light, BEF8 collects light by using the effect of a prism to improve the brightness, and DBEF9 reuses light that does not pass through the polarizing plate to improve the brightness. Both BEF8 and DBEF9 are rectangular like the flutter 5, and a circular hole 23 with the same diameter as the circular holes 20, 21, 22 is formed at a position overlapping with the central circular holes 20, 21, 22 of BEF8, and a circular hole 24 with the same diameter as the circular hole 23 is formed at a position overlapping with the central circular hole 23 of DBEF9. The circular holes 23, 24 overlap in this order from the back side to form an integrated circular hole.

[0025] The case member 10 is a resin case formed, for example, from a synthetic resin material, and has a bottom wall portion 25 covering the back side of the circuit board 15, and a peripheral wall portion 26 surrounding the sides of the display panel 2, backlight 3, flutter 5, diffuser plate 6, diffuser plate 7, BEF 8, and DBEF 9, and has a roughly box-like shape with an opening on the front side.

[0026] In the bottom wall portion 25 , a circular hole 27 having the same diameter as the circular hole 18 is formed at a position overlapping the circular hole 18 .

[0027] Further, the front end 28 of the peripheral wall portion 26 abuts against the light blocking portion 19 of the cover glass 4 from the rear side.

[0028] Camera 11 has sensitivity in the near-infrared region and captures an image of the face of driver D who is seated in the driver's seat and viewing display panel 2 with infrared light (near-infrared light), and the state (behavior) of driver D can be detected from facial movements and the like in the captured image. Camera 11 is disposed outside case member 10 at a position facing circular holes 18, 20, 21, 22, 23, 24, and 27 so that its angle of view is not blocked by bottom wall portion 25.

[0029] The infrared light irradiating units 12 irradiate infrared light toward the driver D for imaging by the camera 11, and are disposed in pair at the left and right front end portions 28 of the peripheral wall portion 27 of the case member 10. The infrared light irradiating units 12 can be an infrared light source such as a near-infrared LED.

[0030] The above-mentioned components constitute the vehicle instrument 1. In this configuration, the infrared light emitted from the infrared light emitting unit 12 passes through the light shielding portion 19 of the cover glass 4, is irradiated toward the driver D, and reaches the driver D's face.

[0031] The infrared light reflected by the face of the driver D can pass through the cover glass 4, the display panel 2, the circular hole 24 in the DBEF 9, the circular hole 23 in the BEF 8, the circular hole 22 in the diffuser plate 7, the circular hole 20 in the flutter 5, the circular hole 21 in the diffuser plate 6, the circular hole 18 in the circuit board 15, and the circular hole 27 in the case member 10, and enter the camera 11. As a result, the camera 11 captures an image of the face of the driver D illuminated by the infrared light, and obtains the captured image.

[0032] Next, the electrical configuration of the vehicle instrument 1 will be described with reference to Fig. 4. As described above, the vehicle instrument 1 includes the control unit 17, the display panel 2, the light source 16, the camera 11, and the infrared light emitting unit 12, which are connected by flexible wiring or a wiring pattern.

[0033] The control unit 17 has a ROM (Read Only Memory) in which its operating program is stored, a CPU (Central Processing Unit) that executes the operating program to perform the operation processing of the control unit 17, and a RAM (Random Access Memory) used as a work area for the CPU etc.

[0034] The control unit 17 executes a process for displaying the vehicle speed display portion 14 and the like on the display surface 13 based on information from an on-board ECU (Electronic Control Unit) not shown.

[0035] In addition, the control unit 17 executes a process to turn on the backlight 3, for example, based on an operation to turn on an accessory switch (not shown). As a result, the light emitted from the light source 16 is incident on the diffusion plate 6, the flutter 5, and the diffusion plate 7, where it is diffused, and then incident on the BEF8 and DBEF9, where the brightness is increased, and then incident on the display panel 2 to backlight the vehicle speed display unit 14, etc.

[0036] At this time, the light incident on the diffuser 6, the flutter 5 and the diffuser 7 is guided to the peripheral surface 29 of the circular hole 20, the peripheral surface 30 of the circular hole 21 and the peripheral surface 31 of the circular hole 22, leaks out from the peripheral surfaces 29, 30 and 31 into the internal spaces of the circular holes 20, 21 and 22, and also reaches the central portion 32 that covers the camera 11 of the display panel 2 from the front side.

[0037] Furthermore, the control unit 17 judges the state of the driver D based on the image captured by the camera 11. Specifically, the control unit 17 executes a process of judging the state of the driver D, such as whether or not the driver D is drowsy, whether or not the driver D is looking away while driving, based on the image captured by the camera 11.

[0038] Then, for example, when the control unit 17 determines that the driver D is drowsy, it executes a process of operating a speaker (not shown) mounted on the vehicle instrument 1 so that a warning sound (a "beep" sound effect) is emitted from the speaker to call the driver D's attention. Note that, instead of emitting the warning sound, a warning message to call the driver's attention may be displayed on the display surface 13 of the display panel 2 under the control of the control unit 17.

[0039] As described above, in this embodiment, the vehicle instrument 1 comprises a display panel 2, a direct-type backlight 3 having a plurality of light sources 16 arranged therein and illuminating the display panel 2 from the back side, a flutter 5 provided between the display panel 2 and the backlight 3 for diffusing the light emitted from the light sources 16, and a camera 11 for capturing an image of the driver D using infrared light, and a circular hole 20 is formed in the flutter 5 so as to avoid the position where the light source 16 is arranged when viewed from the front, and the light emitted from the light source 16 is guided to the peripheral surface 29 of the circular hole 20, and the camera 11 is positioned in a position facing the circular hole 20.

[0040] Therefore, the light that enters the flutter 5 from the light source 16 and is guided to the peripheral surface 29 of the circular hole 20 leaks from the peripheral surface 29 into the internal space of the circular hole 20 and reaches the central portion 32 that covers the camera 11 of the display panel 2 from the front side, thereby preventing a decrease in its brightness.

[0041] In addition, the backlight 3 includes a circuit board 15 on which a plurality of light sources 16 are arranged, and a circular hole 18 is formed in the circuit board 15 at a position overlapping with the circular hole 20. Among the plurality of light sources 16, light sources 16b, 16c, 16f, and 16g are located in the vicinity of the circular hole 18 on a virtual circumference C1 of radius L / (√2) centered on the center point O of the circular hole 18. Therefore, when the light sources 16 are already provided at a density of pitch L in the backlight 3, the cameras 11 can be installed without reducing the number of light sources, and the decrease in brightness due to the installation of the cameras 11 can be suppressed.

[0042] Furthermore, BEF8 and DBEF9 are provided between the display panel 2 and the flutter 5 to increase the brightness of the light emitted by the light source 16. A circular hole 23 is formed in the BEF8 at a position overlapping with the circular hole 20, and a circular hole 24 is formed in the DBEF9 at a position overlapping with the circular hole 20. Therefore, the BEF8 and DBEF9 increase the brightness without interfering with the reception of infrared light by the camera 11.

[0043] Furthermore, since the brightness is improved, it is possible to reduce the number of light sources 16, thereby reducing costs including power consumption, and making it easier to install the cameras 11 (by increasing the pitch L).

[0044] Second embodiment FIG. 5 shows an example in which an acrylic plate 33 coated with white ink that diffuses light emitted from a light source 16 and transmits infrared light is provided in place of the BEF 8 and DBEF 9 in the vehicle instrument 1.

[0045] In this embodiment, since the acrylic plate 33 transmits infrared light, there is no need to provide a hole in the portion covering the camera 11, and the brightness difference between the portion of the display panel 2 covering the camera 11 (central portion 32) and the other portions is reduced, which further prevents the driver D viewing the display panel 2 from feeling uncomfortable due to the brightness difference.

[0046] Third embodiment FIG. 6 shows an example in which light sources 16 are arranged on a circuit board 15 of a vehicle instrument 1 so that the spacing between light sources 16 is narrower near the circular hole 18 than in other parts other than the vicinity of the circular hole 18. Specifically, light sources 16i, 16j, 16k, and 16m are arranged within an area of ​​radius R surrounded by light sources 16b, 16c, 16f, and 16g so that the pitch is L1 at a location that is more than the distance R away from the center point O of the circular hole 18, and the pitch is L2 (L1>L2) at a location that is less than the distance R away.

[0047] In this embodiment, the brightness around the circular hole 20 into which the light emitted from the light sources 16i, 16j, 16k, and 16m, which are closely spaced in the flutter 5, enters increases, and as a result, the amount of light leaking from the peripheral surface 29 into the internal space of the circular hole 20 increases, making it possible to further prevent a decrease in brightness in the central portion 32 covering the camera 11 of the display panel 2 from the front side.

[0048] The present invention is not limited to the above-described embodiment and drawings. Changes (including deletion of components) can be made to the embodiment and drawings as appropriate without departing from the spirit of the present invention.

[0049] For example, the circular holes 18, 20, 21, 22, 23, 24, 27 and the camera 11 may be provided at a position covered by other parts instead of the central part 32 of the display panel 2, the circular holes 18, 20, 21, 22, 23, 24, 27 may be changed to holes of a shape other than a circle, or may be a through part other than a hole penetrating the front side and the back side. As an example, if the camera 11 is provided at a position covered by an end (upper end, lower end, left end, or right end) instead of the central part 32 of the display panel 2, the flutter 5, the light shielding plates 6, 7, the BEF8, the DBEF9, and the bottom wall part 25 of the case member 10 may be formed with a missing part (notch) instead of a hole, and in this case, the light emitted from the light source 16 is guided to the inner wall surface of the missing part of the flutter 5.

[0050] Furthermore, camera 11 may be provided inside case member 10, such as in circular hole 18, or in bottom wall 25, instead of outside case member 10, and the installation position of infrared light irradiator 12 is not limited to peripheral wall 26 of case member 10. If all or a part of bottom wall 25 is configured to be transparent to infrared light and camera 11 is installed on the back side thereof, circular hole 27 in bottom wall 25 is not necessary.

[0051] Furthermore, instead of the acrylic plate 33 in the second embodiment, another member that diffuses the light emitted by the light source 16 and transmits infrared light may be provided, and an acrylic plate coated with a diffusion ink containing pearl that diffuses visible light may be used as the diffusion plate 6 or 7 without providing the acrylic plate 33. [Explanation of symbols]

[0052] 1 Vehicle instrument (display device) 2 Display device 3. Backlight 5 Flutter (light control components) 8 BEF (Brightness enhancing material) 9 DBEF (Brightness enhancing material) 11 Camera (imaging means) 15 Circuit Board 16 light source 18 Circular hole (second penetration, third penetration) 20 Circular hole (first penetration part) 23 Circular hole (fourth penetration) 24 Circular hole (fourth penetration) 29 Circumference (inner wall surface) 33 Acrylic plate (diffusion material) C1 Virtual circumference C2 Virtual Circumference D Driver (photographed person) L Pitch (arrangement interval) L1 pitch (arrangement interval) L2 pitch (placement interval) O center point

Claims

1. A display panel; a direct-type backlight having a plurality of light sources arranged therein and illuminating the display panel from the rear side; a light control member provided between the display panel and the backlight, the light control member diffusing light emitted from the light source; imaging means for imaging a person to be imaged by infrared light; In the light control member, a first through-portion penetrating from the front side to the rear side is formed so as to avoid the arrangement position of the light source in a front view, and the light emitted from the light source is guided to an inner wall surface of the first through-portion, The imaging means is disposed at a position facing the first penetration portion, the backlight includes a circuit board on which the light sources are disposed, a third through-portion penetrating the circuit board from the front side to the rear side at a position overlapping with the first through-portion; The display device, characterized in that the plurality of light sources are arranged on the circuit board so that the spacing between the light sources is narrower near the third through hole than in other parts other than the vicinity of the third through hole.

2. a luminance increasing member that increases the luminance of light emitted from the light source is provided between the display panel and the light control member; 2. The display device according to claim 1, wherein the brightness enhancing member has a fourth through portion penetrating from the front side to the rear side at a position overlapping with the first through portion.

3. 2. The display device according to claim 1, wherein a diffusion member for diffusing light emitted from the light source and transmitting the infrared light is provided between the display panel and the light control member.

Images