JP3115653B2 - Photo 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 photo camera.

[0002]

2. Description of the Related Art In a photo camera (film camera),
When the light amount of the subject is insufficient, a strobe is usually used. 2. Description of the Related Art Conventionally, there has been known an apparatus which detects a light amount by a light amount sensor such as a photodiode and automatically emits a strobe when the light amount is insufficient.

[0003]

However, according to the light amount sensor, the light amount of the entire image pickup screen is detected. Therefore, when capturing an image of a person or the like in a backlight state where the amount of light is large on the entire screen, it is recognized that the amount of light of the subject is sufficient and the strobe is not emitted. Therefore, a person or the like in a backlight state is imaged with insufficient light quantity.

Accordingly, the present invention provides a photo camera capable of capturing an image of a target object to be captured with a sufficient amount of light.

[0005]

According to the present invention, there is provided an image pickup device, a strobe light emitting means, and a window pattern which is one of a plurality of window patterns set in advance corresponding to a predetermined area of a screen based on focus information. A pattern selecting means for selecting one of a plurality of window patterns respectively corresponding to a predetermined area of the screen, based on focus information indicating which position of the subject has been focused,
Signal extraction means for extracting a signal corresponding to one window pattern selected by the pattern selection means from an imaging signal output from the imaging element; and level detection means for detecting the level of the signal extracted by the signal extraction means. And control means for controlling the light emission of the strobe light emitting means based on the detection output of the level detecting means.

[0006]

In the above configuration, based on the focus information,
A window pattern corresponding to the target subject to be imaged is automatically selected. Therefore, the level detection means detects the level of the imaging signal of the target object, and controls the light emission of the strobe in accordance with the illuminance of the target object. As a result, it becomes possible to image the subject of interest in a state where the amount of light is sufficient.

[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. Reference numeral 7 denotes a shutter button, 8 denotes a film rewind operation button, and 9 denotes a flash.

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.

The zoom magnification of the imaging lens 2 is adjusted by a 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 for adjusting a zoom magnification. By moving the position of this lens 411 back and forth by rotational driving,
The zoom magnification is adjusted. 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 413, respectively. The input terminals p1 and p2 of the zoom driver unit 413 are respectively connected to the zoom operation switch 4
2 are connected to the fixed terminals on the T and W sides.

In this case, when a high-level "H" signal is supplied to the terminal p1, a 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 movable terminal of the zoom operation switch 42 is connected to a power supply 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. Zoom operation switch 4
When 2 is connected to the T side and the W side, a high-level "H" signal is supplied to terminals p1 and p2 of the zoom driver unit 413, respectively, and zoom adjustment is performed in the TELE direction and the WIDE direction.

FIG. 3 is a schematic diagram of the color coding of the image pickup device 12. 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, charges are mixed in pairs such as B1 and B2. From the horizontal shift register Hreg, A1, A2,.
.. Are output in the B field in the order of B1, B2,.

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),.

Returning to FIG. 2, 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 the CDS circuit 13, reset noise can be reduced as is well known.

Timing pulses required by the image pickup device 12 and the CDS circuit 13 are 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.

The image signal output from the CDS circuit 13 is supplied to a level detection circuit 17a. This detection circuit 17
The output signal a is supplied as a control signal to the iris 11 via the iris driver 17b, and the aperture of the iris 11 is automatically controlled.

Here, a process for obtaining a luminance signal Y and a chroma signal (color difference signal) from the image pickup 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.

R−Y = (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 in 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 imaging signal output from the CDS circuit 13 is supplied to an AGC amplifier 19a. The output signal of the AGC amplifier 19a is supplied to a level detection circuit 19b.
The output signal of the detection circuit 19b is supplied as a control signal to the AGC amplifier 19a via the buffer 19c.

The image signal output from the AGC amplifier 19a is supplied to a low-pass filter 20 constituting a luminance processing section.
Supplied to The low-pass filter 20 performs an addition process (averaging) of adjacent signals. Therefore, a luminance signal Y is output from the low-pass filter 20.

The image signal output from the AGC amplifier 19a is supplied to sample and hold circuits 21 and 22 constituting a chroma processing unit. Sample hold circuit 2
Sampling pulses SHP1 and SHP2 (illustrated by E and F in FIGS. 5 and 6) are supplied from the timing generator 14 to 1 and 22. FIG. 5A shows the signal of the A1 line,
FIG. 6A shows a signal on the A2 line.

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 the fixed terminal b of the direct changeover switch 24 and the 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.

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 a red color difference signal RY in each horizontal period, and the changeover switch 25 outputs a 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, the synchronizing signal SYNC is added to the luminance signal Y, and the color difference signal is quadrature-phase modulated to form the carrier chrominance signal C and the 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. Color video signal S output from encoder 28
The CV is led out to the output terminal 29.

A black-and-white video signal SV (a luminance signal Y to which a synchronization signal SYNC is added) is output from the encoder 28. The black-and-white video signal SV is supplied to an electronic viewfinder 30, and an image screen is displayed on a small CRT. Is done.

The output signal of the AGC amplifier 19a is supplied to a level detection circuit 32 via an attenuator 31. Then, the output signal So of the level detection circuit 32 is supplied to the controller 27.

A window mode setting switch 33 and a shutter switch 35 are connected to the controller 27. The shutter switch 35 is turned on in response to a pressing operation of the shutter button 7 (shown in FIG. 1). Further, the controller 27 is supplied with focus information IFC from a focus mechanism (not shown) of the photo camera unit. In the case of this example, the focus is not adjusted continuously, but is adjusted in several steps, for example.

Here, the window mode is set by turning on the setting switch 33. In this window mode, one window pattern is automatically selected from a plurality of window patterns respectively corresponding to a predetermined area of the screen based on the focus information IFC. That is, when focusing on a target subject to be imaged, a window pattern corresponding to the target subject is selected. In the window mode, a signal Sw corresponding to the window pattern selected by the controller 27 is output, and the signal Sw is supplied to the attenuator 31 as a control signal.

FIGS. 8A and 8B show an example of a window pattern. When the focus is adjusted to focus on the target subject (person) as shown in the figure,
A window pattern in an area indicated by a broken line with respect to the imaging screen 100 is automatically selected. The signal Sw is set to 5 V corresponding to the area indicated by the broken line.

FIG. 9 shows an example of the gain characteristic of the attenuator 31. When the control signal Sw is 5V, the gain is 0 dB. Note that when the setting switch 33 is off and not in the window mode, the signal Sw
The voltage is set to 5 V corresponding to the whole of 00, which is the same as the case where the attenuator 31 is not provided.

The flash 9 emits light from the controller 2
7. That is, when the shutter switch 35 is turned on, if the level of the output signal So of the level detection circuit 32 exceeds the strobe light emission threshold Vth (regardless of whether or not the mode is the window mode), the controller 27 controls the strobe 9 Is supplied, and the flash 9 is controlled to emit light in the next vertical period when the shutter switch 35 is turned on.

In the above configuration, when the setting switch 33 is turned on (shown in FIG. 10B), a window mode is set in synchronization with the next vertical synchronizing signal VD (shown in FIG. 10C). FIG. 10A shows the vertical synchronization signal VD.

In this window mode, when the subject to be imaged is focused, the focus information IFC
, A window pattern corresponding to the target subject is automatically selected.

At this time, a signal Sw corresponding to the window pattern selected by the controller 27 is supplied to the attenuator 31 as a control signal.
A signal corresponding to the selected window pattern is extracted from the output signal a and supplied to the level detection circuit 32. Therefore, the level of the output signal So of the level detection circuit 32 indicates the illuminance of the target subject to be focused and imaged.

When the signal So is in the state shown by the solid line in FIG. 10D, when the shutter switch 35 is turned on at time t1 (shown in FIG. 10E), the signal So exceeds the strobe light emission threshold Vth. The controller 27 supplies a strobe light emission pulse PLG to the strobe 9 in synchronization with the vertical synchronization signal VD (shown in FIG. 10F), and the strobe 9 is turned on in the next vertical period when the shutter switch 35 is turned on.
Emit light (shown in FIG. 10G).

FIG. 10H shows a shutter pulse PSH supplied to a mechanical shutter (not shown) of the photo camera unit, and the mechanical shutter is opened in response to the emission of the strobe light 9 to perform imaging.

Although the detailed description is omitted, even when the setting switch 33 is off and not in the window mode, the generation timing of the strobe light emission pulse PLG and the shutter pulse PSH is the same as in the above-described window mode. Becomes

As described above, in this example, when the focus is set on the target subject in the window mode, the window pattern corresponding to the target subject is automatically selected based on the focus information IFC. Therefore, the level of the output signal So of the level detection circuit 32 indicates the illuminance of the subject of interest, and the light emission of the strobe 9 is controlled based on this signal So. Images can be taken. For example, even when a person or the like in a backlight state is imaged, the strobe light can be emitted to increase the illuminance of the target object only by focusing on the target object, and the backlight can be corrected.

[0055]

According to the present invention, the window pattern corresponding to the target subject to be imaged is automatically selected based on the focus information, so that the illuminance of the target subject can be reduced simply by focusing on the target subject. In response, the strobe is controlled to emit light, so that the subject of interest can be imaged with a sufficient amount of light.

[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 of an image sensor.

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

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 an example of a window pattern.

FIG. 9 is a diagram illustrating gain characteristics of an attenuator.

FIG. 10 is a diagram showing a flash emission operation.

[Explanation of symbols]

 Reference Signs List 1 cabinet 2, 3 imaging lens 4 eyecup 5T, 5W zoom operation button 6 recording button 7 shutter button 9 strobe 12 CCD solid-state imaging device 14 timing generator 16 synchronization generator 19a AGC amplifier 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 31 Attenuator 32 Level detection circuit 33 Window mode setting switch 35 Shutter switch

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/238 G03B 15/03 H04N 5/225

Claims (1)

(57) [Claims] An image pickup device, a strobe light emitting unit, and a plurality of window patterns set in advance corresponding to predetermined areas of a screen based on focus information indicating an object at which position is focused. Pattern selection means for selecting one window pattern; signal extraction means for extracting a signal corresponding to the one window pattern selected by the pattern selection means from an imaging signal output from the imaging element; A photo camera comprising: level detecting means for detecting a level of a signal taken out by means; and control means for controlling light emission of the strobe light emitting means based on a detection output of the level detecting means.