Head-mounted display apparatus, and display method

• US 10,339,896 B2
• Filed: 01/12/2016
• Issued: 07/02/2019
• Est. Priority Date: 01/13/2015
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Usui, Yuuma, Hirano, Shigenobu, Kawashima, Ikue, Katano, Yasuo, Hasegawa, Aino, Ohshima, Atsushi
• Primary Examiner(s): Sun, Hai Tao
• Application Number:
  US15/531,539
• Publication Number:
  US 20170345391A1
• Time in Patent Office: 1,267 Days
• Field of Search: 345589
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G09G 2320/06 Adjustment of display parameters
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: H04N 5/64 Constructional details of receivers, e.g. cabinets or dust covers furniture aspects of television cabinets A47B81/06

Abstract

A head-mounted display apparatus (1) includes an image display part (10) configured to display an image, an optical unit (20, 30, 50) configured to lead the image to an eye of a wearer of the display apparatus (1), a light intensity detector (60) configured to detect light intensity (A) of external light, a dimmer filter (40) configured to vary transmittance to adjust the intensity (B) of the external light reaching the eye of the wearer, and a controller (70) configured to adjust the transmittance of the dimmer filter (40) and the light intensity (C) of a light source of the image display part (10) based on the light intensity (A) of the external light obtained by the light intensity detector (60).

Claims

1. A head-mounted display apparatus comprising:

an image display part configured to display an image;

an optical unit configured to lead the image to an eye of a wearer of the display apparatus;

a light intensity detector configured to detect light intensity of external light;

a dimmer filter configured to vary transmittance to adjust the intensity of the external light reaching the eye of the wearer; and

a controller configured to adjust the transmittance of the dimmer filter and the light intensity of a light source of the image display part based on the light intensity of the external light obtained by the light intensity detector,

wherein the transmittance of the dimmer filter has a value within a range of ±

20% with respect to T calculated by the following formulas (1) and (2), where

T=(C×

k)/(D×

A) 

 

(1)

D=−

log((Lmax−

L0)/(Lmax−

Lmin)) 

 

(2),

wherein T denotes the transmittance of the dimmer filter, C denotes the light intensity of the image, A denotes the light intensity of the external light incident on an incident surface of the display apparatus, Lmax denotes a maximum value of viewability, Lmin denotes a minimum value of the viewability, L0 denotes a threshold of the viewability, and k denotes an image coefficient,

wherein the controller stores an adjustment table in advance, the adjustment table indicating a relationship between the light intensity of the external light, the transmittance of the dimmer filter, and the light intensity of the light source of the image display part, and adjusts the transmittance of the dimmer filter and the light intensity of the light source of the image display part based on the adjustment table,

wherein the controller includes a function to adjust the transmittance of the dimmer filter and the light intensity of the light source of the image display part in a plurality of stages, and automatically adjusts the transmittance of the dimmer filter and the light intensity of the light source of the image display part, based on information on the light intensity of the external light obtained by the light intensity detector and the adjustment table,

wherein the controller creates the adjustment table as required in accordance with a signal from the light intensity detector based on the formulas (1) and (2), and

wherein the controller automatically adjusts the transmittance of the dimmer filter and the light intensity of the light source of the image display part based on the created adjustment table to set the viewability at a level higher than or equal to a threshold.

2. The head-mounted display apparatus as claimed in claim 1, wherein

when the light intensity of the external light is within a first light intensity range, the controller maintains the light intensity of the light source of the image display part constant, and gradually reduces the transmittance of the dimmer filter as the light intensity of the external light becomes higher, and wherein

when the light intensity of the external light is within a second light intensity range higher than the first light intensity range, the controller maintains the transmittance of the dimmer filter constant, and gradually increases the light intensity of the light source of the image display part as the light intensity of the external light becomes higher.

3. The head-mounted display apparatus as claimed in claim 2, wherein

the transmittance of the dimmer filter is fixed to a minimum value in the second light intensity range.

4. The head-mounted display apparatus as claimed in claim 1, wherein

the controller stores two or more adjustment tables, and

the wearer is allowed to select a desired one of the adjustment tables.

5. The head-mounted display apparatus as claimed in claim 1, wherein

the controller starts controlling the dimmer filter before displaying the image on the image display part.

6. The head-mounted display apparatus as claimed in claim 1, wherein

the controller changes the number of gradations of the image displayed on the image display part based on the light intensity of the external light detected by the light intensity detector and the transmittance of the dimmer filter.

7. The head-mounted display apparatus as claimed in claim 1, further comprising:

a transmittance detector configured to detect the transmittance of the dimmer filter, wherein

the controller corrects the transmittance of the dimmer filter based on a detected result of the transmittance detector.

8. The head-mounted display apparatus as claimed in claim 1, further comprising:

a single power supply is used as a power supply to drive the image display part and as a power supply to drive the dimmer filter.

9. The head-mounted display apparatus as claimed in claim 1, wherein

the dimmer filter includes an electrochromic element.