Display Device, Electronic Apparatus and Camera

• US 20080309811A1
• Filed: 02/02/2006
• Published: 12/18/2008
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Fujinawa, Nobuhiro, Ohmura, Akira
• Granted Patent: US 7,796,179 B2
• Time in Patent Office: Days
• US Class Current: 348/333.01
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2320/0238 Improving the black level
• CPC Class Codes: G09G 2320/0613 The adjustment depending on the type of the information to be displayed
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: H04N 23/635 Region indicators; Field of view indicators
• CPC Class Codes: H04N 23/675 comprising setting of focusing regions

Abstract

A display device includes: a transmission-type optical image forming element that forms an image based upon image signals; an illuminating device that illuminates the optical image forming element; and a light adjustment device that allows illuminating light emitted from the illuminating device to the optical image forming element to have a specific light quantity distribution.

Claims

1. A display device, comprising:

a transmission-type optical image forming element that forms an image based upon image signals;

an illuminating device that illuminates the optical image forming element; and

a light adjustment device that allows illuminating light emitted from the illuminating device to the optical image forming element to have a specific light quantity distribution.

2. A display device according to claim 1, wherein:

the light adjustment device is disposed between the illuminating device and the optical image forming element and adjusts a quantity of illuminating light originating from the illuminating device in each unit area.

3. A display device according to claim 2, wherein:

the light adjustment device is constituted with a monochrome liquid crystal panel at which the quantity of illuminating light originating from the illuminating device is reduced in each matrix area.

4. A display device according to claim 3, wherein:

the illuminating device comprises a light guide plate; and

the light guide plate, the liquid crystal panel and the optical image forming element are layered one on top of another.

5. A display device according to claim 2, wherein:

the light adjustment device reduces the quantity of illuminating light for an area to be rendered dark within a display screen.

6. A display device according to claim 2, wherein:

the light adjustment device reduces the quantity of illuminating light when a brightness level indicated in display data is equal to or lower than a predetermined threshold value representing a light leakage inhibiting cutoff point.

7. A display device according to claim 6, wherein:

the light adjustment device increases/decreases the threshold value in correspondence to an illumination brightness level set at the illuminating device.

8. A display device according to claim 2, further comprising:

a control device that controls the light adjustment device so as to reduce the quantity of illuminating light over a range smaller than an area to be displayed with a brightness level lower than a predetermined brightness level.

9. A display device according to claim 8, wherein:

the control device controls the light adjustment device so as to alter in steps a rate at which the quantity of illuminating light is reduced over a boundary of an area where the quantity of illuminating light is to be reduced.

10. A display device according to claim 8, wherein:

the control device determines the area where the quantity of illuminating light is to be reduced based upon brightness information in the image signal corresponding to a target pixel on the optical image forming element and pixels around the target pixel.

11. A display device according to claim 8, wherein:

the control device determines a rate, at which the quantity of illuminating light to illuminate a target pixel is to be reduced based upon brightness information indicated in the image signal corresponding to the target pixel on the optical image forming element and pixels around the target pixel.

12. A display device according to claim 1, wherein:

the light adjustment device is disposed between the illuminating device and the optical image forming element; and

the display device further comprises a light adjustment control device that controls the light adjustment device so as to illuminate specific areas on the optical image forming element with different quantities of illuminating light.

13. A display device according to claim 12, wherein:

the light adjustment control device controls the light adjustment device so as to illuminate an image display area and a character display area with different quantities of illuminating light.

14. A display device according to claim 13, further comprising:

a light emission control device that controls a quantity of light emitted from the illuminating device, wherein;

the light adjustment control device controls the light adjustment device so as to reduce the quantity of illuminating light that has been raised via the light emission control device over the character display area.

15. A camera, comprising:

a display device according to claim 12;

an imaging device; and

a focus adjustment control device, wherein;

the light adjustment control device controls the light adjustment device so as to illuminate an area corresponding to a focus area and an area corresponding to an area other than the focus area with different quantities of illuminating light.

16. A camera according to claim 15, wherein:

the light adjustment control device controls the light adjustment device so as to reduce the quantity of illuminating light, having been raised via the light emission control device, over the area corresponding to the area other than the focus area.

17. A display device according to claim 1, wherein:

the light adjustment device is disposed between the illuminating device and the optical image forming element; and

the display device further comprises a display control device that individually controls the illuminating device and the light adjustment device so as to switch, in response to a display switch instruction, between a normal display mode in which a first light emission quantity is set for the illuminating device and a light reduction rate to be achieved via the light adjustment device is set to a minimum level and a high-quality image display mode in which a second light emission quantity greater than the first light emission quantity is set for the illuminating device and the light reduction rate to be achieved via the light adjustment device is set to the minimum level.

18. A display device according to claim 17, wherein:

the light reduction rate to be achieved via the light adjustment device is controlled in units of specific areas defined on the optical image forming element; and

the display control device also individually controls the illuminating device and the light adjustment device so as to switch in response to a display switch instruction to a second high-quality image display mode in which a third light emission quantity greater than the second light emission quantity is set for the illuminating device and the quantity of illuminating light, used to illuminate an area on the optical image forming element corresponding to display data indicating a display brightness level equal to or lower than a predetermined value, is reduced.

19. A camera comprising:

a display device according to claim 18;

an imaging device that captures a subject image and outputs image data; and

an operation member that generates a signal for setting one of a photographing mode for displaying at the display device an image based upon image data output from the imaging device, a reproduction mode for displaying at the display device an image based upon recorded image data, and a menu mode for displaying menu information at the display device menu information, wherein;

the display control device individually controls the illuminating device and the light adjustment device so as to select a specific display mode in response to the signal generated at the operation member.

20. A camera according to claim 19, wherein:

the display control device individually controls the illuminating device and the light adjustment device so as to switch to the normal display mode when the signal from the operation member indicates one the photographing mode and the menu mode and to switch to the high-quality image display mode when the signal from the operation member indicates the reproduction mode.

21. A camera according to claim 20, wherein:

the display control device individually controls the illuminating device and the light adjustment device so as to switch from the high-quality image display mode to the second high-quality image display mode when the signal from the operation member indicates the reproduction mode and a number of sets of data indicating brightness levels equal to or lower than a predetermined low brightness level and a number of sets of data indicating brightness levels equal to or higher than a predetermined high brightness level contained in the display data are each equal to or greater than a predetermined value.

22. A camera according to claim 20, wherein:

the display control device individually controls the illuminating device and the light adjustment device so as to switch from the high-quality image display mode to the normal display mode when the signal from the operation member indicates the reproduction mode and another signal constituting a thumbnail display instruction is also generated at the operation member.

23. A camera according to claim 20, wherein:

the display control device executes control so as to first switch to the normal display mode and then to the high-quality image display mode after the image is held on display in the normal display mode over a predetermined length of time when the signal from the operation member indicates the reproduction mode.

24. An electronic apparatus equipped with a display device according to claim 1.