JP2011033712A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of preventing cost increase by suppressing an increase in the number of components and controlling color detection of illumination light. <P>SOLUTION: A transmission reflection member 29 transmits first colored light L1 and reflects second colored light L2. A liquid crystal display panel 21 is illuminated with illumination light L3 including the first colored light L1 and the second colored light L2. A diffusion member 201 diffuses the illumination light L3 emitted from the transmission reflection member 29. A detection means 202 detects part of chromaticity of the illumination light L3 emitted from the transmission reflection member 29 and outputs chromaticity data. A control means 56 adjusts power supplied to at least one of first and second light sources 23 and 24 on the basis of the chromaticity data. A reflection part 201a is provided in the diffusion member 201 and reflects part of the illumination light L3 emitted from the transmission reflection member 29 in the direction of the detection means 202. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel and a liquid crystal display device including a light source such as a light emitting diode that illuminates the liquid crystal display panel.

  Conventional liquid crystal display devices are disclosed in Patent Documents 1 and 2. The liquid crystal display device includes a first light source that emits first colored light, a second light source that emits second colored light, and transmits the first colored light and reflects the second colored light. And a liquid crystal display panel illuminated by illumination light including the first colored light and the second colored light, and the first and second light sources emitted from the first and second light sources. The second colored light is respectively incident on the transmission / reflection member in a substantially parallel light beam state, and the substantially parallel light beam emitted from the transmission / reflection member between the transmission / reflection member and the liquid crystal display panel. A diffusion member for diffusing the illuminated illumination light is disposed.

JP 2008-209665 A JP 2007-114743 A

However, such a liquid crystal display device detects the illumination light using a color sensor in order to obtain a certain color of the mixed illumination light even when the temperature changes, and the color sensor detects the illumination light. The microcomputer needs to control the output of each light source based on the chromaticity data, and a dedicated light guide is provided between the reflective / transmissive member and the liquid crystal display panel to obtain illumination light by the color sensor. Therefore, there is a problem that the structure of the liquid crystal display device is complicated because the number of parts increases.
The present invention has been made in view of this problem, and provides a liquid crystal display device capable of performing color detection and control of illumination light while suppressing an increase in the number of components and suppressing an increase in cost.

  The present invention includes a first light source 23 that emits first colored light L1, a second light source 24 that emits second colored light L2, and the second colored light that transmits the first colored light L1. Light is transmitted from the transmissive reflective member 29 that reflects the light L2, the liquid crystal display panel 21 that is illuminated by the illumination light L3 that includes the first colored light L1 and the second colored light L2, and the transmissive reflective member 29. And a diffusing member 201 for diffusing the illumination light L3, detecting chromaticity of a part L4 of the illumination light L3 emitted from the transmission / reflection member 29 and outputting chromaticity data. Detecting means 202 that controls the power supplied to at least one of the first light source 23 and the second light source 24 based on the chromaticity data, and the transmission member provided in the diffusing member 201. Reflector Some L4 of the illumination light L3 emitted from the 29 are those having a reflective portion 201a which reflects the direction of the detector 202.

  In the present invention, the diffusing member 201 is a lenticular lens.

  By providing a diffuser on the diffuser that reflects part of the illumination light emitted from the transflective member in the direction of the detector, the color of the illumination light can be detected and controlled without increasing the number of components, resulting in increased costs. Can be suppressed.

1 is an overview diagram showing an embodiment of the present invention. Sectional drawing which shows embodiment same as the above. The side view which shows embodiment same as the above. Optical path explanatory drawing which shows embodiment same as the above. Optical path explanatory drawing which shows embodiment same as the above. The block diagram which shows embodiment same as the above.

  Hereinafter, an embodiment in which the present invention is applied to a head-up display device 10 will be described with reference to the accompanying drawings.

  The head-up display device 10 is disposed in the dashboard 12 of the vehicle 11 (see FIG. 1). The display light L projected by the head-up display device 10 is reflected by the windshield 13 of the vehicle 11 toward the user 14 of the vehicle 11. The user 14 can visually recognize the virtual image V superimposed on the landscape. In other words, the head-up display device 10 irradiates the windshield 13 with display light L emitted from a liquid crystal display device (described later) provided in the head-up display device 10, and uses the virtual image V obtained by this irradiation as the user 14. To make it visible. Thereby, the user 14 can observe the virtual image V superimposed on the landscape.

  The head-up display device 10 has a liquid crystal display device 20, a reflector 30 and the like housed in a housing 40 (see FIG. 2). Further, as shown in FIG. 3, the liquid crystal display device 20 is arranged between a liquid crystal display panel 21, an illuminating means 22 for illuminating the liquid crystal display panel 21, and a dichroic mirror (to be described later) of the liquid crystal display panel 21 and the illuminating means 22. A diffusion member 201 and a color sensor (detection means) 202 are provided. The color sensor 202 detects the chromaticity of a part L4 of the illumination light L3 reflected by the reflecting portion 201a of the diffusing member 201 and outputs chromaticity data to a microcomputer to be described later.

  The liquid crystal display panel 21 is composed of, for example, a TFT (thin film transistor) type LCD in which a polarizing film is provided on the front and back surfaces of a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates. The liquid crystal display panel 21 can display the measured value of the speed of the vehicle 11 as a numerical value. The display information displayed by the liquid crystal display panel 21 is not limited to the vehicle speed, and may be arbitrary, for example, engine speed, travel distance information, navigation information, and outside air temperature information.

  The illumination means 22 includes a first light source 23, a second light source 24, a first wiring board 25, a second wiring board 26, a first condenser lens 27, and a second condenser lens. 28 and a dichroic mirror (transmitting / reflecting member) 29.

  The first light source 23 includes a plurality of chip-type light emitting diodes that emit green light L1 that is first colored light. Each of the first light sources 23 has a light irradiation region angle having a directivity of approximately 60 degrees to the left and right around the first optical axis C1. This means that each of the first light sources 23 has a light irradiation region angle of approximately 120 degrees.

  The second light source 24 is composed of a plurality of chip-type light emitting diodes that emit red light L2 that is second colored light. As in the case of the first light source 23, each of the second light sources 24 has a light irradiation region angle having a directivity of approximately 60 degrees to the left and right with the second optical axis C2 as the center. . This means that each second light source 24 has a light irradiation region angle of approximately 120 degrees.

  The first wiring substrate 25 is made of, for example, a substantially rectangular aluminum substrate having high thermal conductivity, and a plurality of first light sources 23 are mounted at high density. The second wiring substrate 26 is made of, for example, a substantially rectangular aluminum substrate having high thermal conductivity, and a plurality of second light sources 24 are mounted at high density. The outer shape of the second wiring board 26 is substantially the same as the outer shape of the first wiring board 25.

  The first condenser lens 27 is made of a light-transmitting synthetic resin, and is formed with a plurality of convex spherical portions 27 a that protrude toward the dichroic mirror 29 corresponding to the individual first light sources 23. And the green radiation light emitted from the 1st light source 23 with the said light irradiation area | region angle is located right above the 1st light source 23 so that the light emission surface of the 1st light source 23 may be opposed. The light is irradiated into the first condenser lens 27 through the light receiving surface 27b.

  Of the green irradiation light, the green irradiation light traveling straight on the first optical axis C1 travels straight without being refracted when passing through the first condenser lens 27 and reaches the spherical portion 27a (see FIG. 4, the other green irradiation light is refracted when passing through the inside of the first condenser lens 27 and reaches the spherical portion 27a (see the optical path S2 in FIG. 4).

  Further, the green irradiation light that reaches the spherical surface portion 27a through the optical path S1 is emitted as straight light from the spherical surface portion 27a and guided to the dichroic mirror 29 side (see the optical path S3 in FIG. 4). Further, the green irradiation light that reaches the spherical portion 27a via the optical path S2 is emitted from the spherical portion 27a as straight light that is substantially parallel to the first optical axis C1, and is guided to the dichroic mirror 29 side ( In FIG. 4, refer to the optical path S4).

  Therefore, when the green radiated light (green light L1) emitted from each first light source 23 is emitted from the first condenser lens 27, it is in the state of being made into substantially parallel luminous fluxes like the optical paths S3 and S4. Thus, the light travels toward the dichroic mirror 29 and enters the dichroic mirror 29. In other words, the green radiated light (green light L1) emitted from each first light source 23 is incident on the dichroic mirror 29 through the first condenser lens 27 in a state of being made into a substantially parallel light flux. Become.

  The second condenser lens 28 is made of a translucent synthetic resin, and is formed with a plurality of convex spherical portions 28 a that protrude toward the dichroic mirror 29 corresponding to the individual second light sources 24. The red emitted light emitted from the second light source 24 with the light irradiation region angle is positioned directly above the second light source 24 so as to face the light emitting surface of the second light source 24. The light is irradiated into the second condenser lens 28 through the light receiving surface 28b.

  Of the red irradiation light, the red irradiation light traveling straight on the second optical axis C2 travels straight as it is without being refracted when passing through the inside of the second condenser lens 28 and reaches the spherical portion 28a (see FIG. 5, the other red irradiation light is refracted when passing through the inside of the second condenser lens 28 and reaches the spherical portion 28a (see the optical path T2 in FIG. 5).

  Further, the red irradiation light that reaches the spherical portion 28a via the optical path T1 is emitted as straight light from the spherical portion 28a and guided to the dichroic mirror 29 side (see optical path T3 in FIG. 5). The red irradiation light that reaches the spherical portion 28a via the optical path T2 is emitted as straight light that is substantially parallel to the second optical axis C2 from the spherical portion 28a and guided to the dichroic mirror 29 side ( In FIG. 5, refer to the optical path T4).

  Therefore, when the red emitted light (red light L2) emitted from each second light source 24 is emitted from the second condenser lens 28, it is in the state of being made into substantially parallel luminous fluxes like the optical paths T3 and T4. Thus, the light travels toward the dichroic mirror 29 and enters the dichroic mirror 29. In other words, the red radiated light (red light L2) emitted from each second light source 24 is incident on the dichroic mirror 29 through the second condenser lens 28 in a substantially parallel light flux state. Become. In addition, the shape of the 2nd condensing lens 28 (each spherical surface part 28a) shall be substantially the same as the shape of the 1st condensing lens 27 (each spherical surface part 27a).

  The dichroic mirror 29 has a reflective film 29a formed by vapor deposition on the front surface of the glass substrate (that is, the surface facing the back surface of the diffusing member 201), and the progress of each green light L1 converted into a substantially parallel light flux. It is inclined and arranged so as to have an inclination of approximately 45 degrees with respect to the direction and the traveling direction of each red light L2 converted into a substantially parallel light beam.

  The dichroic mirror 29 transmits the green light L1 emitted from the first light sources 23 and reflects the red light L2 emitted from the second light sources 24. The green light L1 converted into a substantially parallel light beam that passes through the dichroic mirror 29 and the red light L2 converted into a substantially parallel light beam reflected through the dichroic mirror 29 are mixed with each other by the dichroic mirror 29. Each illumination light (each orange light) L3 is led to the diffusing member 201 side as a substantially parallel light beam.

  Here, when the green light L1 (light having passed through the optical paths S3 and S4) converted into a substantially parallel light flux enters the dichroic mirror 29, the perpendicular N and the optical path S3 extending in the vertical direction with respect to the back surface 29b of the dichroic mirror 29. The angle formed by S4 (incident angle of the green light L1 with respect to the dichroic mirror 29) K1 is 45 degrees, which is an ideal incident angle (see FIG. 4). Similarly, the angle (red light L2) formed between the perpendicular line N of the dichroic mirror 29 and the optical paths T3, T4 when the red light L1 (light having passed through the optical paths T3, T4) converted into a substantially parallel light beam enters the dichroic mirror 29. The incident angle K2 with respect to the dichroic mirror 29 is an ideal incident angle of 45 degrees (see FIG. 5).

  Thus, the incident angles K1 of the green light L1 (optical paths S3 and S4) to the dichroic mirror 29 are all constant, and the incident angles K2 of the red light L2 (optical paths T3 and T4) to the dichroic mirror 29 are all constant. Accordingly, the ratio (balance) between the green light L1 and the red light L2 is kept constant in each illumination light (each orange light) L3 that has been converted into a substantially parallel luminous flux emitted from the dichroic mirror 29.

  Therefore, the color unevenness of the illumination light L3 caused by the incident light on the dichroic mirror 29 in a state where the green light L1 and the red light L2 are not converted into substantially parallel light beams as in the conventional case is the green light in the present embodiment. L1 and red light L2 are incident on the dichroic mirror 29 at the ideal incident angles (incidence angles K1 and K2) in a state of being substantially parallel light beams through the first and second condenser lenses 27 and 28, respectively. The illumination light L3 emitted from the dichroic mirror 29 is guided to the diffusing member 201 side in a state in which the color unevenness is eliminated.

  That is, by adopting a configuration in which the green light L1 and the red light L2 are respectively incident on the dichroic mirror 29 at the ideal incident angle, the green light L1 and the red light L2 constituting the illumination light L3 Since the balance is kept constant irrespective of the position of the dichroic mirror 29 (that is, the incident position of the light on the dichroic mirror 29), the illumination light L3 that has been converted into a substantially parallel light beam emitted from the dichroic mirror 29 has uneven color. In this state, the diffusion member 201 is guided.

  The diffusing member 201 is made of a light-transmitting synthetic resin, is formed in a substantially flat plate shape, and is disposed along the back surface of the liquid crystal display panel 21. The diffusing member 201 has a function as a light diffusing plate for diffusing the illumination light L3 that has been converted into a substantially parallel luminous flux emitted from the dichroic mirror 29 and uniformizing the display light L emitted from the liquid crystal display panel 21. Have.

  The diffusing member 201 diffuses the illumination light L3 and makes the display light L uniform, and includes a lenticular lens (a lens configured by arranging a plurality of cylindrical lenses extending in one direction). Further, the diffusing member 201 includes a reflection unit 201 a that reflects the illumination light L 3 in the direction of the color sensor 202 and obtains the reflection light L 4, and a light guide unit 201 b that guides the reflection light L 4 to the color sensor 202.

  The liquid crystal display panel 21 positioned in front of the diffusing member 201 illuminates the illumination light L3 having no color unevenness diffused through the diffusing member 201. Further, the illumination light L3 that illuminates the liquid crystal display panel 21 is diffused and emitted on the front side of the liquid crystal display panel 21 as display light L in which color unevenness is suppressed. The projection 14 is projected onto the windshield 13 side through the concave mirror and the window 40 to be described later of the housing 40, whereby the user 14 can visually recognize the virtual image V in which color unevenness due to the display light L is suppressed.

  As shown in FIG. 2, the reflector 30 includes a concave mirror 31, a holding member 32, and a stepping motor 33. The concave mirror 31 is formed by depositing a metal (for example, aluminum) on a resin (for example, polycarbonate) to form a reflective surface 31a. The reflection surface 31a is a concave surface, and the display light L without color unevenness emitted from the display device 20 (liquid crystal display panel 21) is enlarged to display the virtual image V. The concave mirror 31 is bonded to the holding member 32 with a double-sided adhesive tape. The holding member 32 is made of resin (for example, ABS), and the gear portion 34 and the shaft portion 35 are integrally formed. The shaft portion 35 of the holding member 32 is pivotally supported by the housing 40.

  A gear 36 is attached to the rotation shaft of the stepping motor 33, and the gear 36 is engaged with the gear portion 34 of the holding member 32. The concave mirror 31 is supported so as to be rotatable together with the holding member 32, and the concave mirror 31 can be rotated by the stepping motor 33 to adjust the projection direction of the display light L. The user 14 of the vehicle 11 operates a push button switch (not shown) to adjust the angle of the concave mirror 31 so that the display light L is reflected at the eye position (that is, the virtual image V can be visually recognized).

  The housing 40 accommodates the display device 20 and the reflector 30. The housing 40 is provided with a window 41 from which the display light L is emitted. This window part 41 consists of translucent resin (for example, acrylic), and has a curved shape. In addition, the housing 40 is provided with a light shielding wall 42 to prevent a phenomenon (washout) in which external light such as sunlight is incident on the display device 20 and the virtual image V becomes difficult to see. The light shielding wall 42 has a flat plate shape and is formed so as to hang obliquely from the upper part of the housing 40.

  FIG. 6 is a block diagram showing an electrical configuration of the liquid crystal display device 20. A speed sensor 51 detects the speed of the vehicle 11 and outputs speed data to the microcomputer 52. The color sensor 202 outputs chromaticity data to the microcomputer 52. The microcomputer 52 outputs a drive signal to the liquid crystal display panel 21 via the drive circuit 53, displays the vehicle speed on the liquid crystal display panel 21, and drives the light sources 23 and 24 via the drive circuits 54 and 55. A signal is output to cause the light sources 23 and 24 to emit light. The control means 56 comprises a microcomputer 52 and drive circuits 54 and 55, and based on the chromaticity data output from the color sensor 202, the light sources 23 and 24 so that the illumination light L3 has a desired chromaticity. The drive voltage applied to is adjusted.

  In the present embodiment, the chromaticity of the display light L becomes a desired chromaticity by adjusting the power supplied to the light sources 23 and 24 based on the chromaticity data output from the color sensor 202, and the color sensor. Since 202 does not block the illumination light L3, the liquid crystal display panel is uniformly transmitted and illuminated. In addition, by providing the diffusing member 201 with a reflecting portion 201a that reflects a part L4 of the illumination light L3 emitted from the dichroic mirror 29 in the direction of the color sensor 202, the color of the illumination light L3 can be suppressed without increasing the number of components. Detection and control can be performed to suppress cost increase.

  Further, the green light L1 and the red light L2 emitted from the first and second light sources 23 and 24 are respectively applied to the dichroic mirror 29 in a state of being substantially collimated through the first and second condenser lenses 27 and 28. By being incident, the liquid crystal display panel 21 is illuminated with the illumination light L3 with suppressed color unevenness including the green light L1 and the red light L2, and the display light L with suppressed color unevenness is windshielded. 13 is irradiated. Thereby, the user 14 can visually recognize the display image V in which color unevenness is suppressed.

  In addition, a diffusing member 201 is disposed between the dichroic mirror 29 and the liquid crystal display panel 21 for diffusing the illumination light L3 having a substantially parallel luminous flux emitted from the dichroic mirror 29. As a result, the illumination light L3 having no color unevenness that has been made into a substantially parallel luminous flux is diffused in a predetermined angle range through the diffusion member 201, and then the liquid crystal display panel 21 is irradiated with such diffused light, whereby the display light L is colored. It is emitted in a diffused state with no unevenness.

  With such a configuration, even when the user 14 tries to visually recognize the display image V with the head greatly tilted to the left or right, for example, the display light L is within a predetermined angle range. As a result, the display image V in which color unevenness is suppressed can be viewed well. In other words, even when the user 14 moves slightly from a position where, for example, the display image V in which color unevenness is suppressed can be seen well, and views the display image V from this moved position, the display image V ( Since the change in luminance of the display light L) is suppressed, it is possible for the user 14 to visually recognize a good display form without color unevenness.

  In the present embodiment, an example in which the display light L emitted from the liquid crystal display panel 21 is applied to the windshield 13 has been described. For example, a combiner film that favorably reflects the display light L to the user 14 on the windshield 13. Alternatively, the display light L may be applied to a dedicated reflecting member different from the windshield 13. In the present embodiment, two types of light emitting diodes 20 and 21 having different emission colors are used. For example, three types of light emitting diodes having different emission colors may be used.

DESCRIPTION OF SYMBOLS 20 Liquid crystal display device 21 Liquid crystal display panel 23 1st light source 24 2nd light source 29 Transmission reflection member 56 Control means 201 Diffusion member 201a Reflection part 202 Color sensor (detection means)
L1 1st colored light L2 2nd colored light

Claims (2)

A first light source that emits first colored light, a second light source that emits second colored light, a transmission / reflection member that transmits the first colored light and reflects the second colored light, A liquid crystal display comprising: a liquid crystal display panel illuminated with illumination light including the first colored light and the second colored light; and a diffusing member for diffusing the illumination light emitted from the transmission / reflection member. In the device
Detecting means for detecting a chromaticity of a part of the illumination light emitted from the transmissive reflecting member and outputting chromaticity data; the first light source and the second light source based on the chromaticity data; A control unit that adjusts power supplied to at least one of the light source and a reflection unit that is provided in the diffusion member and reflects a part of the illumination light emitted from the transmission / reflection member toward the detection unit. A characteristic liquid crystal display device.   The liquid crystal display device according to claim 1, wherein the diffusing member is made of a lenticular lens.

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