JPH037183B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fade-in and fade-out functions of a video camera.

Instead of turning the video on and off instantly at the start and end of shooting, the so-called no-signal state is achieved by gradually increasing the signal amplitude from no signal to a specified value, or gradually decreasing the signal amplitude from the specified value. The fade-in and fade-out functions are preferable from the viewpoint of enhancing the operability of the video camera. When equipping a home video camera with this function, the most important thing is that the operation method is simple, since the photographer is not accustomed to operating the video camera.

The disadvantages of the conventional video camera having fade-out and fade-in functions will be explained below with reference to FIG. In the figure, the subject light incident on the lens 1 is converted into an electrical signal by the image sensor in the signal processing circuit 2, and after predetermined signal processing, the encoder 3 adds a synchronizing signal component, and in the case of a color video camera, the color After the signal components are multiplexed, the signal is output from the output terminal 5. Further, this output captured image can be observed on a monitor 4 attached to the video camera (hereinafter, this monitor will be referred to as an electronic viewfinder). Now, the output signal from the output terminal 5 is output from the video tape recorder 12.
(hereinafter referred to as VTR), this VTR12
The start and stop of recording is controlled by the recording button 6 in FIG. In other words, since the press operation of the record button 6 is applied to the flip-flop 7, the flip-flop 7 is
Since the state is inverted each time the record button 6 is pressed, a signal corresponding to the state is outputted to the output terminal 8. Since the VTR 12 starts or stops recording depending on this state, if the VTR 12 is in a stopped state at the time the record button 6 is pressed, it starts recording, and conversely, if it is currently recording, it stops recording. The above is the start of normal recording using the record button 6.
This is a stop operation. Fade-in and fade-out operations are performed using the fade button 9. The staircase waveform that is the output of the fade button 9 is applied to the integrating circuit 10, and the output of the integrating circuit 10 is guided to the aperture of the lens 1 via the aperture control circuit 11, so when the fade button 9 is pressed, the aperture of the lens 1 changes. slowly closes due to the time constant of the integrating circuit 10, and the fade button 9
Keep the aperture of lens 1 closed until you release the button. When the fade button 9 is released, the aperture of the lens 1 slowly opens due to the time constant of the integrating circuit 10. Since the photographing signal appearing at the output terminal 5 becomes smaller as the aperture of the lens 1 closes and becomes larger as it opens, the fade-in operation using the fade button 9 can be performed as follows.

(a) Fade-in operation: This explanation assumes that the VTR has stopped recording.

(Operation a-1) Press the fade button 9 and keep pressing it until you confirm that the image signal on the electronic viewfinder 4 gradually becomes smaller (the monitor image becomes darker) and finally reaches zero.

(Operation a-2) Press the record button 6 to start recording on the VTR.

(Operation a-3) Immediately after operation a-2, release the fade button 9, confirm that the imaging signal gradually appears on the electronic viewfinder 4, and complete the operation.

(b) Fade-out operation...This explanation assumes that the VTR is recording.

(Operation b-1) Press the fade button 9 and keep pressing it until you see that the image signal on the electronic viewfinder 4 gradually decreases and finally disappears.

(Operation b-2) Press the record button 6 to stop recording on the VTR.

(Operation b-3) Release fade button 9.

The above-described operations are not only cumbersome to operate, but also have the disadvantage that inexperienced photographers are often at risk of making a mistake in photographing due to a mistake in the procedure. Furthermore, what is undesirable for photographers who are accustomed to the operation is that it is necessary to start the operation (a-1) long before starting fade-in recording (more precisely, before the time constant of the integrating circuit 10). Moreover, since the photographed image cannot be observed on the electronic viewfinder 4 during the operation (a-1), it is difficult to time the operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a video camera equipped with a fade-in/fade-out circuit that can be easily operated even by an amateur and eliminates the need to rely on experts for the timing of the fade-in operation, while eliminating the drawbacks of the prior art described above. .

The reason that the fade-in and fade-out operations were complicated was that it was necessary to press both the fade button and the record button in a predetermined order and at the right time. In the present invention, by pressing only the fade button, a signal equivalent to pressing the record button is automatically generated in a timely manner.

An embodiment of the present invention will be described in detail below with reference to FIG. In the same figure, lenses 1 to VTR 12 are the same as those of the conventional video camera explained using FIG. 1, so their explanation will be omitted. 13 is an electronic switch that is connected to the A side or B side depending on the state of the flip-flop 7, but remains unchanged while the time constant circuit 100 is in operation; 14 and 113 are OR circuits;
100 is a time constant circuit such as a monostable multivibrator, 110 and 111 are triangular wave generation circuits, and 112
is a negative circuit.

In the configuration shown in the figure, normal recording start and stop operations using the record button 6 are clearly the same as conventional ones, so the fade-in and fade-out operations using the fade button 9 will be explained below using the waveform diagram in FIG. 3. . In FIG. 3, a to h indicate the waveforms or operation concepts of each part, and the horizontal axis is time. First, normal recording will be explained. Assume that the recording button 6 is operated at time T1. As a result of the above-described operation, the flip-flop 7 reverses its state (FIG. 3d) and recording begins (FIG. 3a). When the record button 6 is operated again at time T2, recording is stopped by the same operation as the state of the flip-flop 7 is reversed (FIG. 3d) (FIG. 3a). During this time, a normal image is always obtained on the monitor image obtained by the electronic viewfinder 4 (FIG. 3b).Now, assume that the fade button 9 is pressed at time T3. (FIG. 3e) At this point, the flip-flop 7 indicating the recording state is at a low level, that is, the recording is stopped, so the electronic switch 13 is turned to the fade-in side, that is, to the A side. At the same time, the output of the fade button 9 is applied to the time constant circuit 100, so
The time constant circuit 100 outputs a rectangular wave until time T3' (FIG. 3f), and the triangular wave generating circuit 11
0 and 111 generate triangular waves as shown in FIG. 3g and h, respectively. In this case, as mentioned above, since the electronic switch 13 is on the A side, the output waveform of the triangular wave generating circuit 110 (Fig. 3g) is applied to the aperture control circuit 11, so that the aperture of the lens 1 is adjusted at time T3. It closes rapidly at , and then gradually opens toward time T3'. Therefore, the monitor image on the electronic viewfinder 4 (FIG. 3b) suddenly disappears at time T3 and gradually appears toward time T3. What should be noted here is that the output of the triangular wave generation circuit 110 is the NOT circuit 112 and the OR circuit 11.
3 and 14 to the flip-flop 7, the state is reversed at time T3, that is, the rise time of the triangular wave (FIG. 3d), and recording on the VTR 12 is started. Therefore, the VTR 12 records images that gradually appear from time T3 to time T3' as observed by the electronic viewfinder 4, that is, a fade-in image.

The above is the fade-in operation of the configuration shown in FIG. In this case, at the falling edge of the output waveform of the triangular wave generation circuit 110 (time T3), the flip-flop 7
Although it has been explained that the reversal of the flip-flop 7 occurs at the same time, in reality there is or can be made to have a slight delay time, so it goes without saying that the switching of the electronic switch 13 to the A side occurs before the flip-flop 7 is reversed.

Next, the case where the fade button 9 is pressed at time T4 will be explained. In this case, since the electronic switch 13 is set to the low side, the output signal of the triangular wave generating circuit 111 (h in FIG. 3) is applied to the aperture control circuit 11, so that the recorded image gradually changes from time T4 to T4'. This results in a so-called fade-out image that gradually becomes darker (Figure 3a). At time T4' when the image fades out, the output of the triangular wave generation circuit 111 rises rapidly, so the monitor image (FIG. 3b) returns to a normal image. After that, the state of the flip-flop 7 is reversed and the recording operation of the VTR 12 is stopped, so that the fade-out operation is completed.

As described above with reference to FIGS. 2 and 3, according to the video camera according to the present invention, the fade-in and fade-out functions can be performed with a single touch by operating only the fade button, so that even an amateur can easily and reliably perform the fade-in and fade-out functions.

Further, in addition to being able to monitor the actual recording state using the electronic viewfinder, the present invention has great effects, such as being able to view the photographed image right up to the moment of the fade-in operation.

Furthermore, in the embodiment of the present invention described using FIGS. 2 and 3, the aperture of the lens 1 is controlled via the aperture control circuit 11 to perform fade-in and fade-out operations, but the purpose of this circuit is to Since it is sufficient to gradually increase or decrease the imaging signal according to the control signal, a variable gain amplifier is provided inside the signal processing circuit, and the gain of this amplifier is controlled by the output signal of the electronic switch 13. Needless to say, you can do it this way.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of the configuration of a conventional video camera having fade-in and fade-out functions, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 shows the operation of the configuration shown in Fig. 2. It is a conceptual waveform diagram for explanation. 1: Lens, 2: Signal processing circuit, 3: Encoder, 4: Electronic viewfinder, 6: Record button,
7: Flip-flop, 9: Fade button, 10:
Integral circuit, 11: Aperture control circuit, 12: VTR,
13: Electronic switch, 100: Time constant circuit, 11
0 and 111: triangular wave generation circuit.

Claims (1)

[Scope of Claims] 1. A video camera comprising: gain control means for controlling the gain of an imaging signal; and storage means for storing whether recording of the imaging signal is stopped or in progress; means for generating a first control signal that, when applied to the control means, causes the gain to decrease rapidly and then gradually recover; means for generating a second control signal; and a switching state in which the first control signal is guided to the gain control means when the storage means stores that recording is stopped at the start of a fade; When the fade is in progress, it has a switching state in which the second control signal is guided to the gain control means, and while the control signal is being generated, it has a switching state determined according to the stored contents of the storage means at the time of starting the fade. A video camera equipped with a fade-in and fade-out function, characterized by comprising: a switching means configured to maintain the same state;