JP3048410B2 - Video camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera having a zoom function and an electronic viewfinder.

[0002]

2. Description of the Related Art By using a video camera, it is possible to capture a still image in addition to a moving image. However, the resolution of the video camera is lower than the resolution of the photo camera,
Often, you want to use a photo camera with your video camera. For example, it is conceivable to fix the photo camera to the video camera and operate the shutter of the photo camera while capturing a moving image with the video camera.

[0003]

In this case, if the user can know the field of view of the photo camera with the electronic viewfinder, the user can perform the shutter operation accurately.

Accordingly, an object of the present invention is to display an image pickup screen corresponding to the field of view of a photo camera on an electronic viewfinder.

[0005]

According to the present invention, a video camera having a zoom function and an electronic viewfinder is provided with zoom adjusting means for adjusting a zoom magnification and mode changing means for changing to a photo camera mode. In the photo camera mode, the zoom magnification is adjusted by the zoom adjustment means so that the angle of view of the imaging screen matches the angle of view of the photo camera.

[0006]

In the photo camera mode, the angle of view of the imaging screen coincides with the angle of view of the photo camera, and an imaging screen corresponding to the field of view of the photo camera is displayed on the electronic viewfinder. Therefore, the user can accurately perform the shutter operation of the photo camera while looking at the display screen of the electronic viewfinder.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. In this example, a video camera and a photo camera are integrally formed.

FIG. 1 is a perspective view showing the overall configuration. In FIG. 1, reference numeral 1 denotes a cabinet. Although not shown, the cabinet 1 contains a video camera unit including an image sensor, a signal processing circuit, and the like, and a photo camera unit including a film loading mechanism, a film driving mechanism, and the like.

Reference numeral 2 denotes an imaging lens of a video camera unit,
Reference numeral 3 denotes an imaging lens of the photo camera unit. That is, the optical systems of the video camera unit and the photo camera unit are configured separately. The focal length f of the imaging lens 2 is 7 mm to 42 m
A 6 × m zoom lens is used. On the other hand, as the imaging lens 3, a fixed focal length lens having a focal length f of 55 mm is used.

In the present embodiment, an electronic view finder made of a small CRT is provided in the cabinet 1.
A screen captured by the video camera unit via the imaging lens 2 is displayed on the RT. 4 is an eyecup. In addition,
There is no finder for directly checking the screen imaged by the photo camera unit via the imaging lens 3.

Reference numerals 5T and 5W denote zoom operation buttons for performing zoom operations in the TELE direction and the WIDE direction, respectively. Reference numeral 6 denotes a recording button for performing an operation of recording an imaged video signal output from the video camera unit on a VTR, and reference numeral 7 denotes a shutter button of the photo camera unit. Reference numeral 8 denotes a film rewind operation button.

FIG. 2 shows the configuration of the video camera unit. Image light from a subject is supplied via an imaging lens 2 and an iris 11 to a single-chip CCD solid-state imaging device 12 having complementary color checkerboard color filters.

FIG. 3 is a schematic diagram of the color coding of the image pickup device 12. As shown in FIG. As shown in the figure, field reading is performed. In the A field, charges are mixed in pairs such as A1 and A2, and in the B field, B1 and B2 are mixed.
Charges are mixed in pairs such as 2. Then, from the horizontal shift register Hreg, A1, A in the A field
.., B1, B2,...
The charges are output in the order of.

Here, as shown in FIG. 4, the order of the charges a, b,... Is (Cy +
G), (Ye + Mg),..., (Cy + Mg), (Ye + G),... In the A2 line, and (G + Cy), (Mg + Y) in the B1 line.
e),..., and (Mg +
Cy), (G + Ye),.

The electric charge output from the image pickup device 12 as described above is supplied to a CDS circuit (correlated double sampling circuit) 13, and is taken out from the CDS circuit 13 as an image pickup signal. By using this CDS circuit 13,
As is well known, reset noise can be reduced.

A timing pulse required by the image pickup device 12 and the CDS circuit 13 is supplied from a timing generator 14. The timing generator 14 has 8
fsc (fsc is the color subcarrier frequency) reference clock CK0
, And horizontal and vertical synchronization signals HD and VD are supplied from the synchronization generator 16. On the other hand, synchronization generator 1
6 is a clock CK of 4 fsc from the timing generator 14.
1 is supplied.

An image signal output from the CDS circuit 13 is supplied to a level detection circuit 17, and an output signal of the detection circuit 17 is supplied to an iris driver 18. And
The iris of the iris 11 is automatically controlled by the iris driver 18.

Here, a process for obtaining a luminance signal Y and a chroma signal (color difference signal) from the image signal output from the CDS circuit 13 will be described.

The luminance signal Y is obtained by adding adjacent signals. In FIG. 4, a + b, b +
An added signal of c, c + d, d + e,... is sequentially formed.

For example, the A1 line is approximated by the following equation. Here, Cy = B + G, Ye = R + G, Mg
= B + R.

Y = {(Cy + G) + (Ye + Mg)) × 1/2 = (2B + 3G + 2R) × 1/2 Further, the A2 line is approximated by the following equation.

Y = {(Cy + Mg) + (Ye + G)) × 1/2 = (2B + 3G + 2R) × 1/2 Other lines in the A field and lines in the B field are similarly approximated.

The chroma signal is obtained by subtracting adjacent signals.

For example, the A1 line is approximated by the following equation.

RY = (Ye + Mg)-(Cy + G) = (2R-G) Further, the A2 line is approximated by the following equation.

-(B−Y) = (Ye + G) − (Cy−Mg) = − (2B−G) The other lines in the A field and the lines in the B field are similarly processed with the red color difference signals RY and RY. The blue difference signal-(BY) is obtained alternately in a line-sequential manner.

Returning to FIG. 2, the image signal output from the CDS circuit 13 is supplied to a low-pass filter 20 constituting a luminance processing unit via an AGC circuit 19. The low-pass filter 20 performs an addition process (averaging) of adjacent signals. Therefore, this low-pass filter 2
From 0, a luminance signal Y is output.

The image signal output from the AGC circuit 19 is supplied to sample and hold circuits 21 and 22 constituting a chroma processing unit. Sample and hold circuit 21,
Sampling pulses SHP1 and SHP2 (illustrated by E and F in FIGS. 5 and 6) are supplied from the timing generator 14 to 22.

From the sample and hold circuit 21, (Cy
+ G) or (Cy + Mg) continuous signal S1 is output and supplied to the subtractor 23 (shown in FIGS. 5B and 6B). From the sample and hold circuit 22, (Ye + M
g) or a continuous signal S2 of (Ye + G) is output and supplied to the subtractor 23 (shown in FIGS. 5C and 6C).

In the subtractor 23, the signal S1 is subtracted from the signal S2. Therefore, the subtractor 23 outputs the red difference signal RY and the blue difference signal-(BY), respectively, in a line-sequential manner (illustrated in FIGS. 5D and 6D).

The color difference signal output from the subtractor 23 is supplied to a fixed terminal b of the direct changeover switch 24 and a fixed terminal a of the changeover switch 25 and has a delay time of one horizontal period. The signal is supplied to the fixed terminal on the a side of the changeover switch 24 and the fixed terminal on the b side of the changeover switch 25 via 26.

The switching of the changeover switches 24 and 25 is controlled by the controller 27. That is, one horizontal period during which the red difference signal RY is output from the subtractor 23 is b.
, While one horizontal period during which the blue difference signal-(BY) is output is connected to the a side. The controller 27 is supplied with the synchronization signals HD and VD from the synchronization generator 16 as reference synchronization signals, and is also supplied with a clock CK1 from the timing generator 14.

Since the changeover switches 24 and 25 are switched as described above, the changeover switch 24 outputs the red color difference signal RY in each horizontal period, and the changeover switch 25 outputs the blue color difference signal − ( BY) is output.

The luminance signal Y output from the low-pass filter 20 and the color difference signals (RY) and-(BY) output from the changeover switches 24 and 25 are supplied to an encoder 28. The encoder 28 is supplied with a composite synchronization signal SYNC, a blanking signal BLK, a burst flag signal BF, and a color subcarrier signal SC from the synchronization generator 16.

In the encoder 28, as is well known, a synchronizing signal SYNC is added to the luminance signal Y, a quadrature two-phase modulation is applied to the color difference signal to form a carrier color signal C, and a color burst signal is added. . And
The luminance signal Y and the carrier chrominance signal C are added to form, for example, an NTSC color video signal SCV. Thus, the color video signal SCV output from the encoder 28 is led out to the output terminal 29.

The encoder 28 outputs a black-and-white video signal SV (a luminance signal Y to which a synchronization signal SYNC is added). The black-and-white video signal SV is supplied to an electronic viewfinder 30. Then, an imaging screen is displayed on a small CRT constituting the electronic viewfinder 30.

The zoom magnification of the imaging lens 2 is adjusted by the zoom driver 41. FIG. 7 shows a specific configuration of the zoom driver 41. In the figure, reference numeral 411 denotes a lens constituting the imaging lens 2;
This is for adjusting the zoom magnification. This lens 4
The zoom magnification is adjusted by moving the position 11 back and forth by rotational driving. For example, by rotating to the T side, it is adjusted in the TELE direction, and by rotating to the W side, it is adjusted in the WIDE direction.

The rotation of the lens 411 is performed by a DC motor 412. One end and the other end of the motor 412 are connected to output terminals q1 and q2 of the zoom driver unit 413, respectively. The input terminals p1 and p2 of the zoom driver unit 413 are provided with changeover switches 414 and 4 respectively.
15 movable terminals.

In this case, when a high-level "H" signal is supplied to the terminal p1, current flows through the motor 412 in the direction from the terminal q1 to the terminal q2 (shown by a solid line), and the lens 411 rotates in the T direction. Driven. Conversely, when a high-level "H" signal is supplied to the terminal p2, the terminal q2
, A current flows to the motor 412 in the direction of the terminal q1 (shown by a broken line), and the lens 411 is driven to rotate in the W direction. When a high-level "H" signal is not supplied to either of the terminals p1 and p2, no current flows through the motor 412, the lens 411 is not driven to rotate in any direction, and the position is maintained. Is done.

The fixed terminal on the a side of the changeover switch 414 is connected to the fixed terminal on the T side of the zoom operation switch 42, the fixed terminal on the b side is connected to the power supply terminal, and the fixed terminals on the c and d sides are connected to the power supply terminal. Grounded. The fixed terminal on the a side of the changeover switch 415 is connected to the fixed terminal on the W side of the zoom operation switch 42, the fixed terminals on the b and d sides are grounded, and the fixed terminal on the c side is connected to the power supply terminal. .

The movable terminal of the zoom operation switch 42 is connected to a power terminal. Operation button 5 of cabinet 1 described above
When pressing T and 5W, the zoom operation switch 42 is connected to the T side and the W side, respectively.

By the way, as shown in FIG. 2, a variable resistor 44 constituting a potentiometer is disposed at a position where the lens 411 of the imaging lens 2 is mounted. Variable resistor 44
The mover position is shifted by the rotation of the lens 411, and a voltage corresponding to the zoom magnification is obtained for the mover, and this voltage is supplied to the controller 27 as a detection signal SD. As shown in FIG. 8, the detection signal SD is set to be 1 V at the WIDE end (f = 7 mm) and 4 V at the TELE end (f = 42 mm), for example.

Reference numeral 43 denotes a mode switch.
The movable terminal is connected to the controller 27, the fixed terminal on the N side is grounded, and the fixed terminal on the P side is connected to the power supply terminal. When the changeover switch 43 is connected to the N side, the mode is the normal mode, and when it is connected to the P side, the mode is the photo camera mode.

Even if not described above, the changeover switches 414, 415
Switching is similarly performed in conjunction with the
7.

In the normal mode in which the changeover switch 43 is connected to the N side, the changeover switches 414 and 415 are connected to the a side. In this state, when the zoom operation switch 42 is connected to the T side and the W side, a high level “H” signal is supplied to the terminals p1 and p2 of the zoom driver unit 413, respectively, and the zoom adjustment is performed in the TELE direction and the WIDE direction. Is performed.

In the photo camera mode in which the changeover switch 43 is connected to the P side, the changeover switches 414 and 415 are appropriately switched from the b side to the d side so that the angle of view of the imaging screen matches the angle of view of the photo camera. .

Here, the angle of view will be described with reference to FIG. The angle of view θ can be obtained from the imaging surface size T and the f value (focal length) as shown in Expression 1. In FIG. 9, T 'is the field of view (the imaging range of the subject), and L is the object distance.

[Number 1] θ = 2tan ^-1 T / 2f imaging lens 2 is six times zoom lens of f = 7mm~42mm. When the imaging element 12 is a 1/3 inch, the horizontal size ZH of the imaging surface is 4.9 mm, the vertical size ZV is 3.69 mm, and the diagonal size ZD is 6.13 mm (see FIG. 10). ).

For this reason, the horizontal, vertical and diagonal angles of view θZH, θZV, θW at the WIDE end (f = 7 mm)
θZD is 38.6 °, 29.5 °, and 47.3 °, respectively.
Becomes On the other hand, the horizontal, vertical, and diagonal angles of view θZH, θZV, θZD at the TELE end (f = 42 mm)
Are 6.7 °, 5.0 °, and 8.3 °, respectively.

The imaging lens 3 is a fixed focal length lens of f = 55 mm. When the film is 35 mm, the horizontal size PH of the imaging surface is 36 mm, the vertical size PV is 24 mm, and the diagonal size PD is 43.3.
mm (see FIG. 11).

Therefore, the angles of view θPH, θPV, θPD in the horizontal, vertical, and diagonal directions are 36.2 °, 2
4.6 ° and 43.0 °.

From the above, the relationship between the angles of view of the imaging lens 2 as a zoom lens and the imaging lens 3 as a fixed focus lens is as shown in Table 1.

[0052]

[Table 1]

In the photo camera mode of this example, the horizontal angle of view θZH of the image pickup screen is controlled so as to match the horizontal angle of view θ PH of the photo camera = 36.2 °. That is, from FIG. 8, when the angle of view θZH in the horizontal direction is 36.2 °, the detection signal SD becomes 1.23 V. Therefore, the controller 27 switches the changeover switches 414 and 415 (until the detection signal SD becomes 1.23 V). 7) is switched to the b side or the c side to adjust the zoom magnification. When the detection signal SD becomes 1.23 V, the changeover switches 414 and 415 are set to d.
To the side. As a result, the horizontal angle of view θZH of the imaging screen is fixed to a state that matches the horizontal angle of view θPH of the photo camera. Here, the field of view T 'becomes equal at the same angle of view, and the field of view changes as the angle of view changes. However,
The object distances L are assumed to be equal.

As described above, in the present embodiment, by connecting the changeover switch 43 to the P side to set the camera mode, the horizontal angle of view θZH of the image pickup screen matches the horizontal angle of view θPH of the photo camera. Can be done. Therefore, an imaging screen corresponding to the field of view of the photo camera is displayed on the small CRT screen of the electronic viewfinder 30 (the vertical angle of view does not match, and the vertical direction of the imaging screen is Disagreement with the world). Therefore, the shutter operation of the photo camera can be accurately performed while watching the display screen of the electronic viewfinder 30.

Although the above embodiment is an example in which the horizontal angle of view θZH is matched in the photo camera mode, a configuration in which the vertical angle of view θZV is matched can be similarly configured.

In the above embodiment, the video camera unit and the photo camera unit are integrated.
The present invention is similarly applicable to a type in which a separate photo camera is fixed to a video camera. In this case, for example, a means for inputting data of the angle of view of the photo camera (or data of the focal length f of the imaging lens and data of the size of the imaging surface of the film) to the controller 27 is provided. By making it possible to calculate the detection signal SD when it matches the angle of view of the camera, any type of photo camera can be handled.

[0057]

According to the present invention, in the photo camera mode, the angle of view of the imaging screen matches the angle of view of the photo camera,
Since the electronic viewfinder displays an imaging screen corresponding to the field of view of the photo camera, the user can accurately operate the shutter of the photo camera while viewing the display screen of the electronic viewfinder.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of an embodiment.

FIG. 2 is a diagram illustrating a configuration of a video camera unit.

FIG. 3 is a schematic diagram of color coding.

FIG. 4 is a diagram illustrating an output of a horizontal output register.

FIG. 5 is a diagram for explaining color signal processing.

FIG. 6 is a diagram for explaining color signal processing.

FIG. 7 is a diagram illustrating a configuration of a zoom driver.

FIG. 8 is a diagram illustrating a relationship between a zoom angle of view and a detection signal.

FIG. 9 is a diagram for explaining how to obtain an angle of view.

FIG. 10 is a diagram illustrating the size of an imaging surface of a 1/3 inch CCD solid-state imaging device.

FIG. 11 is a diagram showing the size of an imaging surface of a 35 mm film.

[Explanation of symbols]

 Reference Signs List 1 cabinet 2, 3 imaging lens 4 eye cup 5T, 5W zoom operation button 6 recording button 7 shutter button 12 CCD solid-state imaging device 14 timing generator 16 synchronization generator 20 low-pass filter 21, 22 sample hold circuit 23 subtractor 24, 25 Changeover switch 26 Delay circuit 27 Controller 28 Encoder 29 Output terminal 30 Electronic viewfinder 41 Zoom driver 42 Zoom operation switch 43 Mode changeover switch 411 Lens 412 DC motor 413 Zoom driver section 414, 415 Changeover switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H04N 5/232 G03B 17/48 G03B 19/06 H04N 5/225

Claims (1)

(57) [Claims] In a video camera having a zoom function and an electronic viewfinder, a zoom adjustment unit for adjusting a zoom magnification and a mode changing unit for changing to a photo camera mode are provided. Adjust the zoom magnification with the zoom adjustment means,
A video camera, wherein an angle of view of an imaging screen is matched with an angle of view of the photo camera.