JP3240073B2 - Electronic viewfinder with projection function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic viewfinder provided with a liquid crystal display unit and mounted on a video camera.

[0002]

2. Description of the Related Art In recent years, an electronic viewfinder which drives a liquid crystal display section by an image signal obtained from a video camera and allows a photographer to observe an image displayed on the liquid crystal display section to confirm a subject. It has been known.

[0003] Such an electronic view finder has a cylindrical shape with one end closed, and an image displayed on a liquid crystal display section disposed inside the cylinder can be viewed from the other end through an optical system. It has become.

[0004]

By the way, such an electronic viewfinder reproduces an image signal obtained by photographing substantially in real time, or reproduces an image signal from a recording medium after photographing. Is limited to one person.

In order to view a reproduced image after photographing by a plurality of persons, it is necessary to connect a video camera to an external monitor and reproduce the image on this monitor.

Therefore, in a conventional video camera, it is difficult to play back an image taken outdoors and enjoy it by a plurality of people, because of the power supply of the monitor device and the portability. For example, it has been difficult to photograph children's competitions with a video camera at an athletic meet, and then play back the captured competition images at lunch time outdoors for everyone to enjoy.

In view of such circumstances, the inventors of the present invention have a projector function of projecting an image displayed on a liquid crystal display section of an electronic viewfinder onto a screen outside the finder through an eyepiece through illumination from a light source. An electronic viewfinder has been invented and has been already filed and disclosed (Japanese Patent Application No. 4-153384).

When the electronic viewfinder is used in a normal manner, the user approaches the eyepiece and looks through the viewfinder to directly observe the reproduced image projected on the liquid crystal display. The brightness of the light source for illuminating the display unit may not be so large.

However, when this electronic view finder is used as a projector, it is necessary to project a reproduced image having an easy-to-see brightness on a screen arranged at a distance from the finder eyepiece. The luminance of the light source for illumination needs to be increased in each stage as compared with the normal use.

As described above, when the brightness of the light source is increased and the user inadvertently approaches the eyepiece and intensifies the light, the eye may be damaged.

The present invention has been made in view of such circumstances, and a plurality of persons can easily view a reproduced image simultaneously without using an external display device, and the luminance of the illumination light source is set to be large. It is another object of the present invention to provide an electronic viewfinder having a projection function capable of preventing an unexpected accident such as damage to eyes due to the light.

[0012]

An electronic viewfinder according to the present invention has a projector function of projecting an image displayed on a liquid crystal display section onto a screen outside the viewfinder. In this case, the brightness of the light source is adjusted to be small when an object comes close to the object.

That is, in an electronic viewfinder provided with a liquid crystal display unit mounted on a video camera, an image displayed on the liquid crystal display unit is illuminated by illumination light from a light source, and the image is then placed on the eyepiece of the finder. And a projector function for projecting onto an external screen of the finder through the finder, an object proximity detector for detecting that an object has approached the eyepiece of the finder, and the finder functions as a projector When set as such, when the object proximity detection unit determines that an object is present at a position close to the eyepiece, the brightness of the light source is lower than the brightness when used as a projector. And a dimming unit for adjusting so as to be small.

Here, the electronic view finder is mounted on a video camera, reproduces an image taken by the video camera substantially in real time, and reproduces an image signal from a recording medium after the photographing. A device having an optical system that allows an image displayed on a display unit to be viewed as a virtual image.

The screen includes not only a so-called projector screen, but also anything that can be used as a screen, such as a plain wall or a piece of paper.

[0016]

According to the above construction, a projector function for projecting an image displayed on the liquid crystal display unit to the outside is provided. The projector function can be used not only on the original projector screen but also on a plain wall or a piece of paper. Since the captured image can be displayed in a desired size using the screen substitute, a plurality of persons can view the same image at an arbitrary place at the same time.

In the electronic viewfinder of the present invention, when the finder is set to a projector mode for projecting a photographed image on a screen,
It detects whether or not there is an object close to the eyepiece of the viewfinder, and based on this detection result, reduces the brightness of the illumination light source when there is an adjacent object. Even in the case of looking through the finder in the mode, it is possible to prevent a situation in which strong light enters the observer's eyes. Therefore, it is possible to prevent an accident that the eyes are damaged by strong light.

In particular, in such an electronic viewfinder, the brightness of the light source greatly differs between when using a normal finder and when using a projector. Is extremely valuable.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram showing a general video camera equipped with an electronic viewfinder according to one embodiment of the present invention.

That is, the electronic viewfinder 1 is attached to the side of the video camera main body 2 so that an image photographed through the photographing lens 3 is recorded at substantially the same time as the photographing, or once after recording, on a recording medium (such as a video tape). ) Is played back after recording. Further, the electronic viewfinder 1 has a projector function, and is configured to be able to project an image once recorded on a recording medium to the outside.

The eyepiece 1 of the electronic viewfinder 1
A is provided with a proximity sensor 1B that detects an object approaching and outputs an object detection signal when the object approaches.

FIG. 3 shows an optical system inside the electronic viewfinder 1. FIG. 3A is a schematic view showing an optical arrangement when the electronic viewfinder mode (hereinafter referred to as EVF mode) is set. FIG. 2B is a schematic diagram showing the optical arrangement when the projector mode is set.

That is, in the EVF mode, the light source 10
The light emitted from the light is collimated by a collimator lens 12, illumination unevenness is reduced by a diffusion plate 14, linearly polarized by a polarizing filter 16, and is converted into a liquid crystal display (LCD).
Irradiated at 18. The liquid crystal display panel 18 is driven by an image signal obtained by photographing to display an image, and light transmitted through the liquid crystal display panel 18 carries image information.

The light carrying the image information is transmitted through the eyepiece 20
Is incident, an image display surface of the liquid crystal display panel 18 a distance x ₁ in the eyepiece 20, the eyepiece 20 is positioned set to be smaller than the focal length f of the eyepiece 20, the By looking through the eyepiece 20 in the direction of the liquid crystal display panel 18, a virtual image formed at the back of the liquid crystal display panel 18 can be seen. Thereby, the image displayed on the liquid crystal display panel 18 can be viewed.

Next, fed forward eyepiece 20 by a distance x ₂ when the mode is changed from the EVF mode to the projector mode. This allows the LCD panel 18
The distance between the image display surface and the eyepiece 20 is x ₁ + x ₂ , which is larger than the focal length f of the eyepiece 20.
Therefore, the distance the light carrying image information from the eyepiece 20 after entering the eyepiece 20 of the predetermined X, _{i.e., X = (x 1 + x} 2) f / (x 1 + x 2 -f) ...... (1 An image displayed on the liquid crystal display panel 18 is formed as a real image on the screen 22 at a distance.

A slide switch 24 is provided below the eyepiece 20, and a section of the slide switch 24 moves in accordance with the movement of the eyepiece 20, and the slide switch 24 is moved between the two modes. Switching is performed, and the diffusion plate 14 is moved out of the optical path in the projector mode according to the switching.

One feature of the apparatus of the present invention is that it has a light control mechanism for reducing the brightness of the light source when an object approaches the eyepiece of the finder in the projector mode. In the apparatus of this embodiment, the dimming mechanism is functioned by the configuration shown in FIG.

That is, the apparatus of this embodiment detects whether the mode is set to the EVF mode or the projector mode based on the set position of the slide switch 24 as shown in FIG. When a command signal based on the projector mode is input, a mode detection unit 4 that outputs a corresponding command signal to each unit, and an operation state is activated in response to the command signal, and it is detected whether or not the object is in the proximity position. A proximity sensor 5 that outputs an object proximity signal when in the proximity position is provided. Furthermore, EVF
When the command signal based on the mode is input, the brightness of the light source 10 is reduced, and when the command signal based on the projector mode is input, the brightness of the light source 10 is increased, and based on the object proximity signal input from the proximity sensor 5. The light control unit 6 is provided to reduce the brightness of the light source 10 to the brightness in the EVF mode.

The mode detection unit 4 includes a slide switch 24
The mode detection is performed by electrically detecting whether or not is in a conductive state.

The proximity sensor 5 detects when an object such as a human eye approaches the eyepiece 1A of the finder in the operating state as described above, and outputs an object detection signal to the light control unit 6. It is preferable from the viewpoint of eye protection that the output is a type that can be detected in a non-contact state such as an electrostatic induction type or a light reflection type.

Further, the dimming unit 6 reduces the brightness of the light source 10 when a command signal based on the EVF mode is input so that the brightness of the screen of the liquid crystal display panel 18 when the photographer looks through the finder. Of the light source 10 when a command signal based on the projector mode is input.
Thus, the reproduced image on the liquid crystal display panel 18 is projected onto the screen 22 outside the finder so that the luminance of the finder becomes large. Further, when an object detection signal is input from the proximity sensor 5 when the projector mode is set, the brightness of the light source 10 can be switched to the small brightness in the EVF mode. Even if a situation in which the inside of the eyepiece 1A is looked into is prevented, an accident such as damage to the eyes by strong light can be prevented.

In this projector mode, the light source 10
The form of the dimming signal output from the dimming unit 6 to control the luminance of the signal may be such that the magnitude of the signal level changes or that the pulse width changes in a fixed cycle (PW
M).

Further, as described above, in this embodiment, when an object approaches the eyepiece 1A of the finder in the projector mode, the brightness of the light source is switched to the small brightness in the EVF mode. In such a case, the extension position of the eyepiece is also set to the EVF mode position. This allows
When looking through the finder eyepiece 1A, the function of the EVF mode can be exhibited regardless of whether the mode setting is the EVF mode or the projector mode.

Next, the driving scan of the liquid crystal display panel 18 in each mode when the subject 51 as shown in FIG. 4 is photographed by the video camera 52 will be described.

When the video camera 52 is set to the EVF mode, an erect virtual image of the image displayed on the liquid crystal display panel 18 is viewed. Therefore, the driving scan of the liquid crystal display panel 18 is performed at the upper left of the screen as shown in FIG. From the bottom right ((1), (2)
, (3) ... in that order).

On the other hand, when the video camera 52 is set to the projector mode, the liquid crystal display 18
An inverted real image of the image displayed above is formed.

Therefore, in the case of the transmission type screen 22a, as shown in FIG. 6A, the liquid crystal display plate 18 is moved from the lower right to the upper left ((1), (2), (3)... (In this order), it is necessary to invert the display image on the liquid crystal display panel 18 both vertically and horizontally.

Further, in the case of the reflection type screen 22b, as shown in FIG. 6B, the liquid crystal display panel 18 is moved from the lower left to the upper right (see (1), (2), (3). (In order), the display image on the liquid crystal display panel 18 needs to be inverted only in the vertical direction.

As described above, since the driving scan direction of the liquid crystal display panel 18 is different for each mode or screen type, in the present embodiment, the liquid crystal display panel 18 is driven in accordance with these modes or types. The drive scanning direction is switched.

FIG. 7 is a block diagram showing a control system for performing drive scanning of the liquid crystal display panel 18 and adjusting the luminance of the light source 10 and the extending position of the eyepiece 20.

This control system circuit receives an X / Y scanning direction switching signal and an image signal, and determines whether to perform X scanning from left or right or Y scanning from above or below according to the switching signal. A liquid crystal display panel controller 26 for sending command signals to the X-direction driver 28 and the Y-direction driver 30 is provided.

Therefore, in the present embodiment, when the mode is set to the EVF mode, the controller
In response to a command signal from 26, X scanning is performed from the left and Y scanning is performed from above, and an image as shown in FIG.

When the mode is set to the projector mode and the screen 22 is set to select the transmissive type 22a, the X scan is performed from the right side and the Y scan is performed in accordance with the command signal from the controller 26. Is performed from below to form an image on the liquid crystal display panel 18 as shown in FIG.

When the mode is set to the projector mode and the reflection type screen 22b is selected as the screen 22, the X scan is performed from the left in the Y scan in accordance with the command signal from the controller 26. Is performed from below to form an image on the liquid crystal display panel 18 as shown in FIG. 6 (b).

The switching between the X and Y scanning directions is performed by a switching signal from the microprocessor 31.

That is, the microprocessor 31 receives an object proximity signal from the proximity sensor 1B and a mode detection signal from the slide switch 24, and further receives a screen type signal from a manual switch (not shown). An X / Y scanning direction switching signal is sent to the LCD controller 26 based on this.

The microprocessor 31 sends an eyepiece extension signal to the motor driver 32 and a light source luminance switching signal to the luminance switching switch 33 in addition to the X / Y scanning direction switching signal.

The motor driver 32 drives the motor 34 in accordance with the eyepiece lens extension signal, and extends the inner cylinder with the eyepiece 20 attached to the motor 34 to a predetermined position. On the other hand, the luminance switch 33 switches the luminance of the light source 10 according to the light source luminance switching signal.

That is, the EV is operated by the slide switch 24.
When it is detected that the mode is the F mode, the eyepiece 20 is set at the position shown in FIG. 3A, and the brightness changeover switch 33 is connected to the low brightness side terminal 35b, so that the light source 10 has a small current. And the light source 10 is in a low-luminance state.

When the slide switch 24 detects that the projector mode is set, the eyepiece 20 is set at the position shown in FIG. 3B, and the luminance changeover switch 33 is connected to the high luminance side terminal 35a. As a result, a large current flows through the light source 10, and the light source 10 enters a high brightness state.

Further, even when the projector mode is detected, when the proximity sensor 1B detects that an object has approached, the eyepiece 20 is returned to the position shown in FIG. The switch 33 is also connected to the low-luminance side terminal 35b and set to a low-luminance state.

As described above, the electronic viewfinder can take either the EVF mode or the projector mode. However, when an object approaches the eyepiece 1A in the projector mode, the electronic viewfinder is returned to the EVF mode. It is supposed to be.

FIG. 8 shows an operation flow of the microprocessor 31 in the control system circuit.

First, when it is confirmed that the power of the camera is turned on (S1), an eyepiece extension signal is sent from the microprocessor 31 to the motor driver 32, and the eyepiece 20 is moved to the EVF mode position (FIG. 3). (position (a)) is set (S2).

Next, a light source luminance switching signal is sent from the microprocessor 31 to the luminance switching switch 33, whereby the switch 33 is connected to the low luminance side terminal 35b, and the light source 10 is set to the low luminance state (S3). . That is, the EVF mode is set in the initial state.

Next, the microprocessor 31 determines the current setting mode based on the input from the slide switch 24 (S4).

If the result of this mode determination is that the EVF mode has been set, the light source 10 is set to a low-luminance state (S5), and thereafter the eyepiece 20 is set to the EVF mode position. It is determined whether or not the eyepiece 20 is set (S6), and if not set, the eyepiece 20 is set to the position of the EVF mode (S7).

On the other hand, if the result of the mode determination indicates that the projector mode has been set, the microprocessor determines whether the proximity sensor 1B is in the ON state, that is, whether the object is at a close position. 31 judges (S8).

If the result is ON, step S
The operation of 5, S6, S7 is performed to set the EVF mode state.

On the other hand, if it is in the OFF state, it is determined whether or not the eyepiece 20 is set to the position of the projector mode (the position of FIG. 3B) (S9), and the following operation is performed.

That is, if it is determined that the eyepiece 20 is not set at the position of the projector mode, an eyepiece extension signal is transmitted from the microprocessor 31 to the motor driver 32, and the motor 34 is driven based on the signal, and The position of the eyepiece 20 in the projector mode (FIG. 3)
(position (b)) (S10), and a light source luminance signal is sent from the microprocessor 31 to the luminance changeover switch 33, which is connected to the high luminance side terminal 35a,
The light source 10 is set to a high brightness state (S11).

The above-described mode determination (S4) and a series of operations (S5 to S11) based on the determination result are repeated at a constant cycle.

The electronic viewfinder according to the present invention is not limited to the above-described embodiment, but various modifications can be made.

For example, in the above-described embodiment, the extension operation of the eyepiece 20 and the brightness switching operation of the light source 10 are automatically performed based on the result of the mode detection and the signal input from the proximity sensor 1B. Alternatively, only the brightness switching operation of the light source 10 can be made automatic.

Further, in the above embodiment, the brightness of the light source 10 is reduced to the brightness when the EVF mode is set when a nearby object is detected. It is not always necessary to set the brightness in the EVF mode as long as the brightness is reduced to.

Further, since a large amount of heat is generated in the projector mode, a fan for discharging air near the light source 10 to the outside may be provided.

If the television tuner is incorporated in the electronic viewfinder or the camera body, a television image can be projected on a screen by the projector function of the electronic viewfinder. You can enjoy watching. As for the sound, the sound signal may be reproduced by an external speaker or headphones having a built-in amplifier. The TV tuner may be of an adapter type that can be attached at the time of use.

If a small screen for a speaker or a projector is attached to the camera body, it is convenient without having to carry these separately.

Although the electronic viewfinder of the present invention has a projector function so that a photographed image can be projected on a screen, an image signal is output to a terminal of a camera body like a normal video camera. If it is made possible, the captured image can be reproduced on a television screen, for example, indoors.

[0071]

As described above, the electronic viewfinder according to the present invention has a projector function. Further, in the projector mode, when an object is present at a position close to the eyepiece, an illumination light source is provided. Since the brightness of the image is reduced, a plurality of persons can simultaneously enjoy the photographed image even in a place where there is no television receiver, such as outdoors, and this is necessary because both the projector mode and the EVF mode are provided. Its practical value is extremely high because certain safety measures are taken.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a light control mechanism of an electronic viewfinder according to an embodiment of the present invention.

FIG. 2 is an external view of a general video camera in which an electronic viewfinder according to an embodiment of the present invention is mounted.

FIG. 3 is a schematic diagram for explaining an optical system of the electronic viewfinder shown in FIG. 2;

FIG. 4 is a schematic diagram for explaining how driving scanning of a liquid crystal display panel differs depending on a mode in the electronic viewfinder shown in FIG. 2;

FIG. 5 is a diagram illustrating an electronic view finder shown in FIG.
Schematic diagram for explaining driving scanning of the liquid crystal display panel in the VF mode

6 is a schematic diagram for explaining driving scanning of a liquid crystal display panel in a projector mode in the electronic viewfinder shown in FIG. 2;

FIG. 7 is a block diagram showing a control circuit system of the electronic viewfinder shown in FIG. 2;

FIG. 8 is a flowchart for explaining the operation of the circuit shown in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic view finder 1B Proximity sensor 2 Camera body 4 Mode detection part 5 Proximity sensor 6 Light control part 10 Light source 12 Collimator lens 18 Liquid crystal display panel 20 Eyepieces 22, 22a, 22b Screen 24 Slide switch 31 Microprocessor 32 Motor driver 33 Luminance Selector switch 34 Motor

Continuation of front page (56) References JP-A-5-347724 (JP, A) JP-A-5-344393 (JP, A) JP-A-5-344392 (JP, A) JP-A-4-307875 (JP) JP-A-4-287574 (JP, A) JP-A-4-252572 (JP, A) JP-A-3-231572 (JP, A) JP-A-3-78374 (JP, A) 5-18171 (JP, U) Hira 4-61975 (JP, U) Hira 1-1115371 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/225 H04N 5/74

Claims (1)

(57) [Claims] 1. An electronic viewfinder provided with a liquid crystal display unit mounted on a video camera, wherein an image displayed on the liquid crystal display unit is illuminated by illumination light from a light source, and the image is provided by an eyepiece of the finder. And a projector function of projecting onto an external screen of the finder through the finder, an object proximity detector for detecting that an object has approached the eyepiece of the finder, and the finder functions as a projector When set as such, when the object proximity detection unit determines that an object is present at a position close to the eyepiece, the brightness of the light source is lower than the brightness when used as a projector. An electronic viewfinder having a projection function, comprising: a light control unit that adjusts the size of the electronic viewfinder to be smaller.