JP3005030B2 - Video camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera, and more particularly to a video camera, in which a specific character signal such as a character or a figure is displayed together with a video signal obtained by imaging on a finder and output to an external device. Regarding possible video cameras.

2. Description of the Related Art FIG. 4 shows an example of a configuration for superimposing a character signal on a video signal in this type of video camera.

In FIG. 4, reference numeral 1 denotes an imaging unit of a video camera, 2 denotes a camera signal processing circuit for outputting an electric signal from the imaging unit 1 as a video signal having a predetermined signal state, and 3 denotes an external output terminal. A switch (hereinafter simply referred to as a "displace switch") for instructing whether or not to output character information of a micro processing unit (MPU);
a is a character generation circuit for generating a character signal indicating a character such as a graphic character, 6 is an electronic view finder (hereinafter referred to as EVF), 7 and 9 are adders, and 8 is an external output terminal.

Hereinafter, the operation of the video camera having the configuration shown in FIG. 4 will be described.

The MPU 4a controls the operation of the character generation circuit 5a in accordance with the operation or state of the displacement switch 3. When the displace switch 3 is turned on, the character generating circuit 5a outputs a signal of a specific character, that is, a signal of a character that can be externally output from the output line OUT1, and supplies the signal to the adder 7.

For this particular character, the year of the auto dating,
Information such as month, day, hour, minute, etc., a title, a tape counter value in a camera-integrated VTR, operation mode information, and the like are included.

On the other hand, a character signal including the signal of the specific character is always supplied to the adder 9 from another output line OUT2 of the character generating circuit 5a. Here, this output line OUT2
May be only the specific character described above, but may also include signals of other characters that should only display the EVF 6.

Other characters include various warning information such as battery power reduction and dew condensation, and a tracking frame of an automatic tracking auto focus.

First, when no character is output to the external output terminal 8, the displace switch 3 is turned off. At this time, nothing is output from the output line OUT1, and only the video signal output from the camera signal processing circuit 2 is output from the external output terminal 8. Then, this video signal is output to the output line OUT2 by the adder 9.
And is supplied to the EVF 9. Therefore, the above-mentioned specific character is displayed on the EVF 6 together with the captured image. Further, if there is another character described above, this is also displayed.

Next, when outputting the specific character to the external output terminal 8, the displace switch 3 is turned on. In this case, a signal indicating the specific character is output from the output line OUT1.
Is added to the video signal. Therefore, a signal indicating the specific character is output to the external output terminal 8. In addition, since the character signal of the output line OUT2 is always output, the above-mentioned specific character and other characters are displayed on the EVF 6 together with the shot image.

[Problem to be Solved by the Invention] However, in the configuration of FIG. 4, a signal indicating a specific character is added to the video signal twice by the adder and the adder 9. The level of the signal of the specific character input to the EVF 6 differs depending on whether the signal indicating this specific character is output from the external output terminal 8 or not. Therefore, a specific character of the EVF becomes bright when an external output is performed. This is very annoying to the photographer and may be interpreted as a malfunction of the device in some cases.

In addition, when other characters are simultaneously displayed, a difference in brightness occurs between the characters, and even if one character is displayed at an optimum luminance, the other is too bright or too dark to be very difficult to read. Would.

As a solution to this, it is conceivable to input the video signals output from the camera signal processing circuit 2 to the adders 7 and 9 in parallel. However, the circuits within the dotted lines in FIG. 4 are often incorporated in a single IC, and if such a configuration is taken, the adder 7 cannot be used. Is actually provided, which is not preferable in terms of configuring hardware.

Under such a background, the present invention can make the brightness of a character displayed on a finder constant regardless of whether or not the character is output to an external output terminal, and is also advantageous in a hardware configuration. The purpose is to provide.

[Means for Solving the Problems] Under such a purpose, in the video camera of the present invention, a first signal to which a video signal obtained by imaging is input is provided.
, An external output terminal for outputting the output signal of the first adder to the outside, a second adder receiving the output signal of the first adder, and the second adder And a selection circuit for selectively inputting a predetermined character signal to the first adder and the second adder.

[Operation] With the above-described configuration, the first or second adder adds the signal to the signal input to the finder only once, regardless of whether the predetermined character signal is externally output or not. That is, there is no difference in luminance between characters.

[Example] Hereinafter, an example of the present invention will be described.

FIG. 1 is a diagram showing a schematic configuration of a video camera as one embodiment of the present invention. In FIG. 1, the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, reference numeral 4b denotes an MPU, which outputs from the control terminal CONT a control signal which becomes low level (Lo) when the displace switch 3 is on and high level (Hi) when it is off.
The character generation circuit 5b always outputs a signal indicating the above-mentioned specific character to be externally output to the output line OUT2.
10 and 11 are analog switches, respectively, and 12 is an inverter.

 Hereinafter, the operation will be described.

Control terminal when device switch 3 is off
The control signal from CONT is Hi, and the switch 11 is turned on. The output of the inverter 12 becomes Lo, and the switch 10 is turned off. Therefore, the video signal output from the camera signal processing circuit 2 is output from the external output terminal 8 as it is. On the other hand, this video signal is supplied to the adder 9 and the switch 11
Is added to the character signal input via
Supplied to F6. Along with this, a specific character is displayed together with the captured image in the EVF 6.

Next, when the displace switch 3 is turned on, the control signal is Lo, the switch 11 is turned off, and the switch 10 is turned on. Therefore, the character signal is added to the video signal output from the camera signal processing circuit 2 by the adder 7 and output to the external output terminal 8. On the other hand, since the switch 11 is off, the character signal is not added in the adder 9 and the signal output to the external output terminal 8 is directly supplied to the EVF 6, and the EVF 6 displays the captured image and the specific character. You.

According to the above-described configuration, it is possible to prevent the occurrence of a luminance difference between characters by using the configuration within the dotted line as it is and with a simple circuit configuration. That is, when a predetermined character signal is input to the adder 7, the character signal is not input to the adder 9, and the character signal is output regardless of whether the character is output to the outside or not. It is not added twice.

FIG. 2 is a diagram showing a schematic configuration of a video camera as another embodiment of the present invention, in which the same components as those in FIG. 1 are denoted by the same reference numerals.

In the figure, 14 and 15 are digital transistors, which are controlled by a control signal from a control terminal CONT. That is, when the control signal is Lo, the transistor 15 is turned on and the transistor 15 is turned on.
14 becomes non-conductive. When the control signal is Hi, the transistor 14 is turned on and the transistor 15 is turned off.

The flow of the character signal and the video signal itself in the configuration of FIG. 2 is the same as that of FIG. 1, and the same effect can be obtained.

FIG. 3 is a diagram showing a schematic configuration of a video camera as still another embodiment of the present invention, and the same components as those in FIG. 1 are denoted by the same reference numerals. The character generating circuit 5c in FIG. 3 always outputs the signal of the specific character described above from the output line OUT3, and outputs the signals of the other characters from the output line OUT4. 17 is an adder.

To output a character to the external output terminal 8,
The switch 10 is turned on and the switch 11 is turned off, and a signal of a specific character is output to the terminal 8. This signal is added to the signal of the other character by the adder 17 via the adder 9, and the above-mentioned specific character and the other character are displayed with the same brightness in the EVF 6 together with the image.

When the character output is not performed to the external output terminal 8, the switch 10 is turned off and the switch 11 is turned on.
In EVF6, a particular character and another character are displayed with the same brightness.

Thus, in the embodiment shown in FIG. 3, even if there is a character that can be displayed only on the EVF 6, it can always be displayed with the same brightness as a specific character that can be output to the outside.

Although the displace switch 3 in the above embodiment is described as being operated manually, it is also possible to adopt a configuration in which it is turned on and off in accordance with the operation of the camera or turned on and off by a remote controller.

In addition, in the example of FIG.
The same operation is performed at a position on the input side of which does not affect the output signal to the terminal 8. For example, it can be provided between the switch 11 and the adder 9.

[Effects of the Invention] As described above, the video camera of the present invention is advantageous in terms of hardware configuration, and regardless of the presence or absence of the output of a character signal to an external output terminal, a character having a first-time brightness in a finder is always provided. Can be projected.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a video camera as one embodiment of the present invention, FIG. 2 is a diagram showing a schematic configuration of a video camera as another embodiment of the present invention, and FIG. FIG. 4 is a diagram showing a schematic configuration of a video camera as still another embodiment. FIG. 4 is a diagram showing a configuration example of a conventional video camera. In the figure, 1 is an imaging unit, 2 is a camera signal processing circuit, 4a and 4b are microprocessing units (MPUs), 5a, 5b and 5c are character generation circuits, and 6 is an electronic view finder (EV).
F), 7, 9 and 17 are adders, 8 is an external output terminal, 10 and 11 are analog switches, 12 is an inverter, and 14 and 15 are digital transistors.

Claims (2)

(57) [Claims] 1. A first adder to which a video signal obtained by imaging is inputted, an external output terminal for outputting an output signal of the first adder to the outside, and an output of the first adder. A second adder to which a signal is input, a finder for displaying an output signal of the second adder, and a predetermined character signal selectively input to the first adder and the second adder Video camera with selection circuit. 2. A video camera according to claim 1, wherein a character signal other than said predetermined character signal is added at a stage subsequent to said external output terminal. camera.