Liquid crystal area dimming device for vehicle-mounted naked-eye 3D projection optical engines

Abstract

A liquid crystal local dimming device for an in-vehicle naked-eye 3D projection optical engine includes a lower polarizer layer, a liquid crystal dimmer, and an upper polarizer layer. The liquid crystal dimmer has multiple dimming units, which are aligned with the pixels of the liquid crystal display panel and can be individually adjusted to allow light to pass through. Each dimming unit is controllable and will increase or decrease the transmittance according to the displayed image on the liquid crystal display panel to achieve the function of local dimming of the displayed image. The liquid crystal local dimming device, in conjunction with the working mechanism of the in-vehicle naked-eye 3D projection optical engine, performs local dimming of the left / right eye display image projected by the liquid crystal display panel, which can improve the contrast of the 3D image projected by the in-vehicle naked-eye 3D projection optical engine and improve problems such as image motion trailing, image quality crosstalk, and glare caused by ambient light.

Claims

1. A liquid crystal area dimming device for an in-vehicle naked-eye 3D projection optical engine, the in-vehicle naked-eye 3D projection optical engine comprising a stacked liquid crystal display panel and a liquid crystal light valve device, the liquid crystal display panel being used to project a display image, the liquid crystal light valve device being capable of rapidly and alternately switching the left / right eye switching areas of the liquid crystal light valve device over time, so that the display image projected by the liquid crystal display panel is divided into left / right eye display images to form a 3D image, the liquid crystal area dimming device comprising: The display panel comprises a lower polarizer layer, a liquid crystal dimmer, and an upper polarizer layer. The liquid crystal dimmer is disposed on one side of the lower polarizer layer, and the upper polarizer layer is disposed on one side of the liquid crystal dimmer. An OCA layer is disposed on one side of the upper polarizer layer, and a liquid crystal light valve device is disposed on one side of the OCA layer. The liquid crystal dimmer has multiple dimming units, each of which is aligned with a pixel of the liquid crystal display panel. Each dimming unit can be controlled to adjust the transmittance of light. Any dimming unit can be controlled to increase or decrease the transmittance according to the displayed image shown by the pixels of the liquid crystal display panel, thereby achieving the function of dimming a local area of ​​the displayed image.

2. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 1, wherein, The liquid crystal dimmer has a liquid crystal optical mode of either passively driven display TN mode or OCB mode, or actively driven display TN mode, FFS mode, VA mode, or ECB mode.

3. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 1, wherein, The vehicle-mounted naked-eye 3D projection optical engine also includes an image enhancement system. The liquid crystal dimmer and the liquid crystal light valve device are each electrically connected to the image enhancement system via a flexible circuit board. The liquid crystal dimmer receives the dimming circuit waveform signal transmitted by the image enhancement system through the flexible circuit board, enabling the dimming unit to adjust the transmittance of light separately. The liquid crystal light valve device receives the left / right eye time-separated circuit waveform signal transmitted by the image enhancement system through the flexible circuit board, causing the left / right eye switching areas of the liquid crystal light valve device to switch rapidly and alternately over time.

4. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 1, wherein, The shape of each dimming unit is one of hexagonal, rectangular, triangular, elliptical, and circular.

5. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 3, wherein, When the liquid crystal dimming device is working, the dimming unit is driven by the dimming circuit waveform signal transmitted by the image enhancement system, and switches between the on state where the dimming unit displays the maximum brightness and the off state where the dimming unit displays the minimum brightness. The speed at which the dimming unit switches between the on state and the off state is between 2 and 8.6 milliseconds.

6. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 5, wherein, The dielectric anisotropy Δε of the liquid crystal in the liquid crystal dimming device is between 4 and 7; the rotational viscosity of the liquid crystal in the liquid crystal dimming device is between 45 and 70 mPa·s; the liquid crystal elastic coefficient K11 of the liquid crystal in the liquid crystal dimming device is between 16 and 20; and the ratio of the rotational viscosity to the liquid crystal elastic coefficient K11 of the liquid crystal in the liquid crystal dimming device is between 1.5 and 3.88; so that the photoelectric response speed of the liquid crystal in the dimming unit changes between the on and off states in 2 to 4.6 milliseconds.

7. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 1, wherein, The liquid crystal clearing point of the liquid crystal in the liquid crystal dimming device is between 110 and 120 degrees Celsius.

8. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 1, wherein, When the optical mode of the liquid crystal in the liquid crystal dimmer is TN mode, the ratio of the liquid crystal cell thickness to the pitch of the liquid crystal in the liquid crystal dimmer is between 0.35 and 0.6, so that the liquid crystal in the liquid crystal dimmer can be stably twisted under the electric field without optical jump phenomenon.

9. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 1, wherein, The optical absorption axis of the lower polarizer layer and the optical absorption axis of the upper polarizer layer intersect at an angle between 88 and 92 degrees.

10. The liquid crystal area dimming device for a vehicle-mounted naked-view 3D projection optical engine as described in claim 1, wherein, The size of the dimming unit of the liquid crystal dimmer is equal to the size of one or more pixels of the liquid crystal display panel of the vehicle-mounted naked-eye 3D projection optical engine.

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