Head up display for vehicle

• US 10,018,840 B2
• Filed: 10/27/2016
• Issued: 07/10/2018
• Est. Priority Date: 02/12/2016
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Youngjin, Ryu, Juhyeok, Kim, Dongwook, Lee, Kyoungil, Lee, Seunggyu
• Primary Examiner(s): Lavarias, Arnel C
• Application Number:
  US15/335,857
• Publication Number:
  US 20170235136A1
• Time in Patent Office: 621 Days
• Field of Search: 359 1, 359 13, 35948301, 35948801, 35948901, 35948907, 35948908, 35948911, 35948915, 35948916, 3594892, 35949101
• CPC Class Codes: B60K 2360/27 using semi-transparent optical elements
• CPC Class Codes: B60K 2360/334 Projection means
• CPC Class Codes: B60K 2360/347 Optical elements for superposition of display information
• CPC Class Codes: B60K 35/00 Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
• CPC Class Codes: B60K 35/213 Virtual instruments
• CPC Class Codes: B60K 35/23 Head-up displays [HUD] optical aspects of head-up displays G02B27/01
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 2027/0152 involving arrangement aiming to get lighter or better balanced devices
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0149 characterised by mechanical features G02B27/0176 takes precedence
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001

Abstract

A head up display for a vehicle according to an embodiment includes a display panel configured to emit an image light; a polarized light plate configured to make the image light emitted from the display linearly polarized; a reflective mirror configured to reflect the image light onto a windshield of a vehicle; a polarized light reflective mirror configured to be disposed to face the reflective mirror; and a phase delay mirror configured to convert a phase of the light inputted from the polarized light plate and reflect the converted phase to the polarized light reflective mirror, and to convert a phase of the light reflected from the polarized light reflective mirror and reflect the converted phase to the polarized light reflective mirror, thereby minimizing a width in the forward and backward direction.

Claims

1. A head up display for a vehicle, comprising:

a display panel configured to emit an image light;

a polarized light plate configured to convert the image light emitted from the display panel into linearly polarized light;

a phase delay mirror configured to receive light from the polarized light plate;

a polarized light reflective mirror configured to receive light reflected from the phase delay mirror; and

a reflective mirror,

wherein the phase delay mirror is further configured to convert a phase of the light received from the polarized light plate into a first converted phase, and to reflect the first converted phase to the polarized light reflective mirror,

wherein the polarized light reflective mirror is further configured to reflect the first converted phase back to the phase delay mirror,

wherein the phase delay mirror is further configured to convert the first converted phase of the light reflected from the polarized light reflective mirror into a second converted phase, and to reflect the second converted phase back to the polarized light reflective mirror,

wherein the polarized light reflective mirror is further configured to pass the second converted phase to the reflective mirror, and

wherein the reflective mirror is configured to reflect the second converted phase onto a windshield of a vehicle.

2. The head up display of claim 1, wherein the phase delay mirror is larger in size than each of the polarized light plate and the polarized light reflective mirror, and

wherein the phase delay mirror faces the polarized light plate and the polarized light reflective mirror.

3. The head up display of claim 1, wherein a linearly polarized light having the same waveform as the linearly polarized light emitted from the polarized light plate is transmitted to the polarized light reflective mirror.

4. The head up display of claim 1, wherein a surface of the phase delay mirror includes an overlapped area where an area facing the polarized light reflective mirror and an area facing the polarized light plate are overlapped.

5. The head up display of claim 1, wherein the polarized light plate and the polarized light reflective mirror are non-parallel with one another.

6. The head up display of claim 1, wherein a portion of the polarized light plate is disposed between the polarized light reflective mirror and the phase delay mirror.

7. The head up display of claim 1, wherein uppermost portions of the phase delay mirror and the polarized light reflective mirror are closer to one another than lowermost portions of the phase delay mirror and the polarized light reflective mirror.

8. The head up display of claim 1, wherein lowermost portions of the phase delay mirror and the polarized light reflective mirror are closer to one another than uppermost portions of the phase delay mirror and the polarized light reflective mirror.

9. The head up display of claim 1, further comprising a holder in which the polarized light plate, the polarized light reflective mirror and the phase delay mirror are arranged.

10. The head up display of claim 9, wherein the holder includes an inner holder having a front upper opening located in an upper front portion of the inner holder, a front lower opening located in a lower front portion of the inner holder, and a rear opening located in a rear portion of the inner holder,

wherein the polarized light reflective mirror is disposed in the front upper opening,

wherein the polarized light plate is disposed in the front lower opening, and

wherein the phase delay mirror is disposed in the rear opening.

11. The head up display of claim 10, wherein the holder further includes:

a phase delay mirror cover configured to be coupled to the inner holder and to cover a rear surface of the phase delay mirror; and

a polarized light reflective mirror cover configured to be coupled to the inner holder and to cover a front perimeter of the polarized light reflective mirror.

12. A head up display for a vehicle, comprising:

a main body having a space therein;

a display panel configured to emit an image light;

a reflective mirror disposed in the space; and

a mirror assembly disposed apart from the reflective mirror,

wherein the mirror assembly includes;

a holder;

a polarized light plate located in the holder and configured to convert the image light emitted from the display panel into linearly polarized light;

a phase delay mirror located in the holder and configured to receive light from the polarized light plate; and

a polarized light reflective mirror located in the holder and configured to receive light reflected from the phase delay mirror,

wherein the phase delay mirror is further configured to convert a phase of the light received from the polarized light plate into a first converted phase, and to reflect the first converted phase to the polarized light reflective mirror,

wherein the polarized light reflective mirror is further configured to reflect the first converted phase back to the phase delay mirror,

wherein the phase delay mirror is further configured to convert the first converted phase of the light reflected from the polarized light reflective mirror into a second converted phase, and to reflect the second converted phase back to the polarized light reflective mirror,

wherein the polarized light reflective mirror is further configured to pass the second converted phase to the reflective mirror, and

wherein the reflective mirror is configured to reflect the second converted phase onto a windshield of a vehicle.

13. The head up display of claim 12, wherein the phase delay mirror is larger in size than each of the polarized light plate and the polarized light reflective mirror, and

wherein the phase delay mirror faces the polarized light plate and the polarized light reflective mirror.

14. The head up display of claim 12, wherein a linearly polarized light having the same waveform as the linearly polarized light emitted from the polarized light plate is transmitted to the polarized light reflective mirror.

15. The head up display of claim 12, wherein a surface of the phase delay mirror includes an overlapped area where an area facing the polarized light reflective mirror and an area facing the polarized light plate are overlapped.

16. The head up display of claim 12, wherein the polarized light plate and the polarized light reflective mirror are non-parallel with one another.

17. The head up display of claim 12, wherein a portion of the polarized light plate is disposed between the polarized light reflective mirror and the phase delay mirror, and

wherein uppermost portions of the phase delay mirror and the polarized light reflective mirror are closer to one another than lowermost portions of the phase delay mirror and the polarized light reflective mirror.

18. The head up display of claim 12, wherein the holder includes an inner holder having a front upper opening located in an upper front portion of the inner holder, a front lower opening located in a lower front portion of the inner holder, and a rear opening located in a rear portion of the inner holder,

wherein the polarized light reflective mirror is disposed in the front upper opening,

wherein the polarized light plate is disposed in the front lower opening, and

wherein the phase delay mirror is disposed in the rear opening.

19. The head up display of claim 18, wherein the holder further includes a phase delay mirror cover configured to be coupled to the inner holder and to cover a rear surface of the phase delay mirror.

20. The head up display of claim 18, wherein the holder further includes a polarized light reflective mirror cover configured to be coupled to the inner holder and to cover a front perimeter of the polarized light reflective mirror.