JP2003348497A - Display apparatus and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display apparatus for selecting the luminance of a light emitted from a light source to a display screen of a display means depending on the state of the apparatus and to provide an imaging apparatus. <P>SOLUTION: The luminance of a light from a backlight is brought into a lower luminance darker than the luminance so far on the basis of a signal denoting activated strobe charging. The selection is controlled to a backlight adjustment section so as to darken the luminance level of the light from the backlight. On the other hand, the luminance of the light from the backlight is restored to the luminance before the reduction on the basis of a signal denoting deactivated strobe charging. The restoration is applied to the backlight adjustment section to make the luminance level of the light from the backlight bright as its control. That is, since a change in the lightness of the light emitted from the backlight to the display screen of an LCD can explicitly recognize whether or not the strobe charging section is under charging, a photographer can easily grasp whether or not the strobe is under charging. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and an image pickup device provided with display means for displaying an image indicated by image information, such as a liquid crystal display (LCD), an organic EL (Electro-Luminescence) display, a plasma display, etc. It is about.

[0002]

2. Description of the Related Art Some conventional digital cameras and the like are provided with an external monitor (display means) such as an LCD and a strobe lighting device for obtaining brightness necessary for photographing. In this type of digital camera, a large amount of current is consumed while the main capacitor of the strobe lighting device is charged, and light emission from a strobe light emitting unit (such as a discharge tube) of the strobe lighting device is generally performed while charging is not completed. Is limiting. Therefore, in a conventional digital camera or the like, a user is informed that a strobe lighting device is in a charging period by lighting a light emitting element such as an LED.

[0003]

By the way, in the prior art described above, the fact that the strobe lighting device is in the charging period is displayed only by lighting the LED. That is, L
It is difficult to grasp (view) whether or not the charging period is in progress only by turning on the ED.

Some conventional digital cameras and the like turn off an LCD that consumes a large amount of power during the charging period of the main capacitor as disclosed in Japanese Patent Application Laid-Open No. 11-112845. However, the invention according to the above publication aims at a power saving effect and does not display that the strobe lighting device is in the charging period.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display device and an imaging device that switch the luminance of light emitted from a light source to a display screen by a display means in accordance with the state of the device.

[0006]

According to a first aspect of the present invention, there is provided a display means for displaying an image indicated by image information, a light source for irradiating the display screen by the display means and imparting luminance, It is characterized by comprising switching means for switching the luminance of light emitted from the light source to the display screen, and control means for controlling switching of the switching means in accordance with the state of the apparatus.

The control means switches the luminance of the light emitted from the light source to the display screen by controlling the switching of the switching means in accordance with the state of the apparatus, for example, charging in the strobe lighting device. That is, the control means switches the luminance of the light of the light source with respect to the display screen by the display means according to the state of the apparatus as described above.

According to the first aspect of the present invention, since the brightness, that is, the brightness of the light emitted from the light source to the display screen changes according to the state of the apparatus, the display brightness of the display screen is recognized. Thus, the state of the apparatus can be easily grasped. The light source is a concept including a backlight.

Note that the switching of the luminance of light by the light source is performed between a preset initial luminance and a modified luminance that increases or decreases to a predetermined level with respect to the initial luminance.
You may make it do. The initial luminance may be based on the level after luminance adjustment performed by the user, for example.

According to the second aspect of the present invention, a photographing means for photographing a subject to obtain image information indicating a subject image, a light emitting means for irradiating light as necessary when photographing the subject, and a light emitting means for emitting light. A charging unit that charges power for causing the display unit to display, a display unit that displays an image indicated by image information, a light source that irradiates light to the display screen by the display unit and gives brightness, and the display screen from the light source. Switching means for switching the luminance of the light applied to the charging section, and control means for controlling switching of the switching means when charging of the charging unit is started and when charging is completed.

The control means switches the luminance of the light emitted from the light source to the display screen by controlling the switching of the switching means at the start of charging the charging unit and when the charging is completed.
According to the second aspect of the present invention, it is possible to clearly indicate whether or not the charging unit is being charged by changing the brightness of the light emitted from the light source to the display screen. It can be easily grasped whether or not.

Note that the switching at the completion of charging may return to the previous luminance (original luminance before the start of charging), or may be a low luminance that is darker than the previous luminance, and vice versa. In addition, the brightness may be higher than the previous brightness. When switching to high brightness, the explicit effect is further improved. The image displayed on the display means is image information obtained by the photographing means.

According to a third aspect of the present invention, in the second aspect of the present invention, the control means switches the luminance of the light of the light source to a luminance different from that at the start of the charging, and when the charging is completed. The switching means is controlled so that the luminance of the light from the light source is restored to the previous luminance.

The control means controls the switching of the switching means so that the light intensity of the light source is switched to a different brightness at the start of charging, and the light intensity of the light source is restored to the previous brightness when charging is completed. Let In the invention according to claim 3, for example, if the switching at the start of the charging is set to a low luminance that is darker than the previous luminance, it can contribute to power saving, so the burden on the power source is reduced.

The image pickup apparatus according to claim 2 or the image pickup apparatus according to claim 3 is a digital still camera, a digital video camera, a mobile phone having an image pickup function, a personal computer, a PDA (Personal Digital Assist).
ance).

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, based on FIGS.
A display device according to an embodiment of the present invention and an imaging device including the display device will be described. 1 is a block diagram of a digital still camera provided with a liquid crystal display (LCD) of the present embodiment, FIG. 2 is a flowchart showing a flow of luminance switching processing in the LCD shown in FIG. 1, and FIG.
These are timing charts regarding the charging of the strobe charging unit shown in FIG.

As shown in FIG. 1, a digital still camera (hereinafter simply referred to as a “digital camera”) 10 includes a mechanical shutter and an aperture for limiting the amount of incident light indicating a subject that has passed through a lens 12 during photographing. (Less than,
(Hereinafter simply referred to as “shutter / aperture”) 14 and an imaging device 1 configured by a CCD that images a subject based on the incident light and outputs an analog image signal indicating the subject image.
8, an analog signal processing unit 20 that performs predetermined analog signal processing on the input signal, and an analog / digital converter (hereinafter simply referred to as “A / D converter”) that converts the input analog signal into a digital signal. 22), a digital signal processing unit 24 that performs predetermined digital signal processing on the input digital signal, and an SDRAM that mainly stores information indicated by the input digital signal
(Synchronous Dynamic Random Access Memory) and the input digital data in a predetermined compression format (in this embodiment, JPEG (Joint Ph
otographic Experts Group) format) while compressing the input compressed digital data in a decompression format corresponding to the compression format, lens 12, shutter / aperture 14, imaging device 18, and light emission A driving unit 32 for driving each of the strobe light emitting units 30 of the means;
It is comprised including.

Image pickup device 1 constituting a part of image pickup means
8 is an input terminal of the analog signal processing unit 20, an output terminal of the analog signal processing unit 20 is an input terminal of the A / D converter 22, and an output terminal of the A / D converter 22 is a digital signal processing unit 24. The output end of the digital signal processing unit 24 is connected to the input end of the memory 26, and an analog image signal obtained by imaging by the imaging device 18 is input to a predetermined analog by the analog signal processing unit 20. After the signal processing is performed and then converted into a digital signal by the A / D converter 22, predetermined digital signal processing is performed by the digital signal processing unit 24 and is temporarily stored in the memory 26 as digital image data.

The predetermined analog signal processing performed by the analog signal processing unit 20 according to this embodiment includes correlated double sampling processing and γ (gamma) correction processing. Here, the correlated double sampling process is particularly effective in reducing thermal noise for a signal to be processed, and improves the S / N ratio (Signal to Noise Ratio).

A lens 12, a shutter / aperture 14, an imaging device 18, and a strobe light emitting unit 30 are connected to the output end of the driving unit 32, and these units are driven by the driving unit 32. The strobe light emitting unit 30 is an auto strobe type that emits light at low illuminance at which an appropriate amount of exposure light cannot be obtained during exposure, and includes a discharge tube, a reflector, and the like.

In FIG. 1, in order to avoid complications,
A state where one line is branched and connected from the driving unit 32 to the lens 12, the shutter / stop 14 and the strobe light emitting unit 30 is shown. They are connected by different wirings, and each unit is driven based on different driving signals.

On the other hand, the digital camera 10 further includes a CPU (Central Processing Unit) 36 serving as a control means for controlling the operation of the entire digital camera 10. Analog signal processing unit 20, A / D converter 22, digital signal processing unit 24, memory 26, compression / decompression unit 28, drive unit 32, digital I / O
F34, CPU 36, operation switch 42, and shutter switch 44 are each connected to the main bus MB.

The main bus MB is connected to a strobe charging unit 31 including a main capacitor and a transformer. The strobe charging unit 31 supplies electric energy to be supplied to the discharge tube of the strobe light emitting unit 30 to the transformer,
It is generated by the main capacitor.

The CPU 36 includes an analog signal processing unit 20,
Control of operations in the A / D converter 22, the digital signal processing unit 24, the compression / decompression unit 28, and the strobe charging unit 31;
Access to an external device connected to the memory 26 and the digital I / F 34, detection of an operation state by the user of the operation switch 42 and the shutter switch 44, and a charging state in the flash charging unit 31 (for example, start or completion of charging, etc.) ) Is detected. That is, the CPU 36
Whether or not the strobe charging unit 31 is being charged is always detected based on, for example, the voltage value at the main capacitor of the strobe charging unit 31.

On the other hand, a timing generator (TG) 33 for generating a timing signal is connected to the main bus MB, and the TG 33 is based on a control signal corresponding to the photographing condition input from the CPU 36, the lens 12, shutter shutter. A drive signal to be supplied to each of the aperture 14, the imaging device 18, and the strobe light emitting unit 30 is generated, and the drive unit 3
2 is supplied.

Further, the TG 33 is a vertical synchronizing signal VD (see FIG. 3) which is a vertical synchronizing signal when displaying an image on a liquid crystal display (LCD) 40 which is a display means, and a horizontal synchronizing signal. A horizontal sync signal is generated. That is, a clock generator (not shown) is connected to the TG 33, and the vertical synchronization signal VD and the like are generated based on the control signal input from the CPU 36 and various signals from the clock generator and the TG 33.

The LCD 40 displays an image indicated by digital image data based on the vertical synchronizing signal VD and the horizontal synchronizing signal. That is, the LCD 40
A moving image (through image) obtained by continuous imaging by the imaging device 18 is displayed.

The output terminal of the memory 26 is connected to a memory card 38 inserted in and attached to the recording medium insertion unit 50 via the compression / decompression unit 28, and the digital image data stored in the memory 26 is compressed / decompressed. After being compressed in a predetermined compression format by the unit 28, it is stored in the memory card 38 as an image file.

The CPU 36 decompresses the compressed digital image data stored in the memory card 38 by the compression / decompression unit 28 and reads it through the memory 26. The other output terminal of the memory 26 is connected to the LCD 40, and the CPU 36 displays a subject image indicated by the digital image data stored in the memory 26 on the LCD 40, various menus and messages via the memory 26, and the like. Is displayed on the LCD 40.

The LCD 40 is a transmissive type that is excellent in visibility, contrast, and the like. However, since it is a light-receiving element that does not emit light by itself, it needs light irradiated from the outside. Therefore, the LCD 40 includes a backlight 40A such as a fluorescent lamp as a light source on the back surface thereof, and is configured to irradiate the LCD 40 with light using the backlight 40A and to provide brightness (brightness).

Connected between the backlight 40A and the main bus MB is a backlight adjusting unit 41 of switching means comprising a changeover switch, a resistor and the like. Then, the CPU 36 performs control for switching the luminance of light in the backlight 40 </ b> A to the backlight adjustment unit 41 by determining when charging is started and when charging is completed in the strobe charging unit 31.

Subsequently, based on FIGS. 2 and 3, the LCD
The luminance switching process at 40 will be described. In addition,
FIG. 2 is executed by the CPU 36 when a power switch (not shown) of the digital camera 10 is turned on by the user. The processing shown in FIG. 2 is performed every predetermined time, for example, every 2 seconds.

On the other hand, FIG. 3 shows a change in the luminance level of the reproduction surface corresponding to on / off of charging of the strobe charging unit 31 (see FIGS. 3C to 3E). The imaging device 18
The through image obtained by the continuous imaging by means of a screen as a reproduction surface by sequentially capturing image data for one screen based on the vertical synchronization signal VD output every predetermined period (for example, 1/30 second). Is displayed. That is, the through image (see reproduction surfaces 1 to 6 shown in FIG. 3B) is switched in synchronization with the vertical synchronization signal VD (FIGS. 3A and 3).
B).

As shown in FIG. 2, in step 100,
Whether or not the flash charging unit 31 needs to be charged is determined based on the voltage value of the flash charging unit 31 or the like.
If step 100 is affirmative, that is, if the voltage value is equal to or lower than a predetermined threshold value, charging is started in step 102, and in step 104, the luminance of the LCD 40 is lowered so as to be different.

That is, in step 104, the backlight 40 is turned on based on the strobe charge on signal (see FIG. 3C).
The brightness of the light A is switched to a lower brightness that is darker than the previous brightness (see FIG. 3D). The switching is controlled by the backlight adjustment unit 41 so that the luminance level of light in the backlight 40A becomes dark (see FIG. 3E).

In step 106, it is determined based on the voltage value of the strobe charging unit 31 whether or not the charging is completed. If step 106 is affirmative, that is, if the voltage value has reached a predetermined threshold value, charging in the strobe charging unit 31 is terminated in step 108 and at step 110 the LCD 4
The brightness at 0 is restored.

That is, in step 110, the backlight 40 is turned on based on the strobe charge off signal (see FIG. 3C).
The brightness of light A is restored to the previous brightness (FIG. 3D
reference). The return is performed on the backlight adjustment unit 41.
Control is performed so that the luminance level of light in the backlight 40A becomes brighter (see FIG. 3E).

Therefore, according to the present embodiment, it is possible to clearly indicate whether or not the strobe charging unit 31 is being charged by changing the brightness of light emitted from the backlight 40A to the display screen of the LCD 40. Therefore, it can be easily grasped whether the photographer is charging.

Further, according to the present embodiment, the light intensity of the backlight 40A is lowered so as to be different from that before the start of charging of the strobe charging unit 31, and the light of the backlight 40A is lighted when the charging is completed. Since the luminance is restored to the previous luminance, it can contribute to power saving, so the burden on the power source is reduced.

As shown in FIGS. 3A and 3C,
The timing for reducing the luminance in step 104 and the timing for returning the luminance in step 110 are the vertical synchronization signal VD
Synchronize with. In the present embodiment, since each of the transition timings is synchronized with the vertical synchronization signal VD, the brightness of the reproduced image is smoothly shifted and flickering of the screen of the reproduced image is prevented.

Further, as shown in FIG. 4, at the start of charging of the strobe charging unit 31 (when the strobe charging is on), the brightness of the light of the backlight 40A is made brighter than the previous brightness and the charging is completed. Hour (strobe charge off)
In addition, the brightness of the light of the backlight 40A may be restored to the previous brightness. In FIG. 4, FIG.
Detailed description of the corresponding parts will be omitted. According to the example shown in FIG. 4, since the fact that charging is in progress can be visually recognized by the light of the backlight 40 </ b> A with increased brightness, the clarification effect is further improved.

It should be noted that the processing flow of the program described in the above embodiment (see FIG. 2) is merely an example, and it goes without saying that it can be changed as appropriate without departing from the gist of the present invention. For example, in the present invention,
Any number of steps (such as three steps) may be used for the luminance change. In the above embodiment, the state of the apparatus is the strobe charging state. However, the present invention can be similarly applied to devices other than the strobe charging state.

In addition to the LCD, the display means according to the present invention may be an organic EL display, a plasma display, or the like, or a display provided with a light source. Furthermore, although the imaging device of the above embodiment is an example of a digital still camera, the imaging device according to the present invention is a digital video camera, a mobile phone having an imaging function, a personal computer, a PDA (Pe
rsonal Digital Assistance) can be applied in the same manner.

[0044]

As described above, according to the present invention,
Since the brightness, that is, the brightness of light emitted from the light source to the display screen changes according to the state of the apparatus, the state of the apparatus can be easily grasped by recognizing the display brightness of the display screen.

[Brief description of the drawings]

FIG. 1 shows a liquid crystal display (L
1 is a block diagram of a digital still camera equipped with a CD).

2 is a flowchart showing a flow of luminance switching processing in the LCD shown in FIG. 1;

FIG. 3 is a timing chart regarding charging of the strobe charging unit shown in FIG. 1;

FIG. 4 is a timing chart showing another example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Digital still camera (imaging device) 12 Lens (imaging means) 14 Shutter / aperture (imaging means) 18 Imaging device (imaging means) 30 Strobe light emitting part (light emitting means) 31 Strobe charging part (charging part) 36 Central processing unit (Control means) 40 Liquid crystal display (display means) 40A Backlight (light source) 41 Backlight adjustment unit (switching means)

Claims (3)

[Claims] 1. A display unit that displays an image indicated by image information, a light source that irradiates light to a display screen by the display unit and gives brightness, and a light source that irradiates the display screen from the light source. A display device comprising: switching means for switching luminance; and control means for controlling switching of the switching means according to the state of the device. 2. A photographing means for photographing a subject to obtain image information indicating a subject image, a light emitting means for irradiating light as needed when photographing the subject, and charging power for causing the light emitting means to emit light. A charging unit; display means for displaying an image indicated by image information; a light source for irradiating light to the display screen by the display means and providing brightness; and brightness of light emitted from the light source to the display screen. An imaging apparatus comprising: switching means for switching between; and control means for controlling switching of the switching means when charging of the charging unit is started and when charging is completed. 3. The control means switches the light brightness of the light source to a brightness different from that at the start of the charging, and returns the light brightness of the light source to the previous brightness when the charging is completed. The imaging apparatus according to claim 2, wherein the switching unit is controlled.