JPH01236779A - Image pickup device - Google Patents

Abstract

PURPOSE:To pick up the image of an object moving at a high speed n a simple circuit constitution without degrading operability by controlling an aperture circuit, which changes the quantity of light incident on an image pickup element, by an aperture control circuit and controlling the storage time of the image pickup element by a storage time control circuit and controlling both control circuits by a mode control circuit. CONSTITUTION:The optical image which has a proper quantity of light through a lens 101 and an aperture circuit 102 of an image pickup device is converted to an image pickup signal by an image pickup element 103, and this signal is amplified to a prescribed value by an amplifying circuit 104 and is inputted to an A/D converting circuit 105. At this time, the output of the circuit 105 is inputted to a signal detecting circuit 107, and a maximum value is detected by the circuit 107 and is inputted to a system control circuit 113. An aperture driving circuit 108 and a driving circuit 110 are controlled through a mode control circuit 112 by the circuit 113. The maximum value can be inputted in the circuit 105 in accordance with following signal processings and relations of S/N, and a photographer can arbitrarily select the shutter speed and the aperture value.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an imaging device such as a video camera.

2. Description of the Related Art Conventionally, in order to improve the operability of imaging devices such as video cameras, automatic aperture control circuits ( It was equipped with a multi-layer LC circuit). As a technique for the personal LO circuit, for example, there is a technique disclosed in Japanese Patent Application Laid-Open No. 58-38076.

FIG. 7 shows a block diagram of this conventional imaging device. In the same figure, 7o1d lens, 702 is a calibration circuit, 703 is an image sensor, 704 is a gain circuit for amplifying the signal from the image sensor 703 to obtain a predetermined novel image signal, and O6 is a digital signal for converting the image signal. Analog-to-digital (M/D) exchange circuit for exchanging signals, 706
707 is a signal processing circuit that performs gamma correction, etc.; 708 is a gain control circuit that controls the gain of the gain circuit 704; 70'9 is an aperture drive circuit that drives the aperture circuit ao2; and 710 is an aperture drive. A control circuit 711 controls the circuit 709, and a seven-stem control circuit 711 comprehensively controls the circuits described above.

The operation of the conventional imaging device configured as described above will be described below. An optical image having an appropriate amount of light after passing through a lens 701 and an aperture circuit 702 is converted into an image signal by an image sensor 703, and a gain circuit 704 sets the amplitude to a predetermined value and inputs it to a MU/D circuit 705. At this time, the Mu/D circuit 70
5, it is necessary to input the maximum value of the specified input due to the subsequent signal processing and S/N relationship, so the signal production circuit 707
The system control circuit 11 controls the aberration drive circuit 709 and the gain circuit 704 so as to detect the maximum (direction).This control method begins with the gain of the gain circuit 704 being constant and changing the aperture according to the brightness of the subject. The circuit is made to respond.At this time, if the imaging signal has reached a predetermined level, the gain circuit remains constant and does not operate, but if the imaging signal has not reached the predetermined level, the gain of the gain circuit is increased and the gain circuit is raised to the predetermined level. This operation is shown in Figure 8. In the figure, (a) is the subject illuminance, and (b) is the amount of light incident on the image sensor (image sensor output signal).
, (T)Bam/D rotation input signal levels and the relationship between these and the control operation.

First, when the subject illuminance is high, use MLC (automatic aperture control).
The aperture circuit is controlled so that the amount of light incident on the image sensor is appropriate within the range (see figure (a)).Next, when the subject illuminance is low, the aperture υ is opened by the mu LC, and then the aperture circuit is controlled by the mu GC (automatic gain control). )'a The gain of the gain circuit is controlled so that the input signal level to the Mu/D circuit is appropriate ((tsu)
(see figure).

When the aperture circuit is manually set, the aperture value is set to a fixed value, and the gain of the gain circuit is controlled so that the S1 value of the image pickup signal is appropriate under that amount of light.

Problems to be Solved by the Invention As mentioned above, the LC has become one of the important functions in current video cameras from the viewpoint of improving operability.

By the way, it is well known that there are two general movements of the cunning circuit: light intensity adjustment and depth of field adjustment, and this is clear when considering the cunning circuit in optical cameras and electronic still cameras. It is.

However, in the LC circuit with the above configuration, the calibration circuit is used only for adjusting the light amount and cannot be used for adjusting the depth of field, so it is not possible to take pictures according to the photographer's intention. Was.

Further, when the aperture circuit is manually set, there are problems in that the operability is reduced and the adjustment range of the gain circuit becomes extremely wide, making the circuit configuration extremely complicated.

Furthermore, since the above configuration does not have a shutter function, there is a problem in that it is not possible to take pictures according to the photographer's intentions when photographing a high-speed moving object, which is one type of video expression. .

In view of these problems, the present invention provides imaging that enables @shi-priority photography that allows you to select the depth of field and shutter speed priority photography that is suitable for photographing high-speed moving objects without reducing operability with a simple circuit configuration. The purpose is to provide equipment.

Means for Solving the Problems In order to achieve the above object, the imaging device A of the present invention includes an aperture circuit, an aperture control circuit, an image sensor layer stacking time control circuit, a distortion control circuit, and an accumulation time control circuit. The imaging device includes a mode control circuit that controls a time control circuit.

Function The mode control circuit in the image pickup device configured as described above can control the aperture value set according to the photographer's intention as well as the storage time of the image pickup device. By controlling the distribution circuit and the storage time control circuit, it is possible to obtain a good video signal with a selected depth of field or shutter speed.

Embodiment FIG. 1 shows a block diagram of an imaging apparatus in a first embodiment of the present invention. In FIG. 1, 101 is a lens, 102 is an aperture circuit, 103 is an image sensor, 104 is an amplifier circuit that amplifies the signal from the image sensor 103, and 106 is an analog-digital (MU/D) circuit that converts the image signal into a digital signal. ) conversion circuit, 106 is a signal processing circuit that performs gamma correction, etc., 107 is a signal extraction circuit, 108 is an aperture drive circuit that drives the aperture circuit 102, 109 is an aperture control circuit that controls the aperture drive circuit 108, and 110 is an imaging circuit. The element drive circuit 111 is a drive control circuit that controls the drive circuit 110, and 112 is a system control circuit that is an aperture control circuit.

The operation of the imaging apparatus of this embodiment configured as described above will be described below. Lens 101 and aperture circuit 10
2, the optical image with an appropriate amount of light is converted into an a-image signal by the image sensor 103, the amplitude is set to a predetermined value by the Masanakatomi circuit 104, and the signal is input to the M/D circuit 105. At this time, it is necessary to input the maximum value of the specified input to the M/D circuit 106 due to the subsequent signal processing and S/H relationship, so the system control circuit 11
3 controls the aperture drive circuit 108 and the drive circuit 110.

At this time, the mode control circuit 112 controls two systems: an aperture control system and a shutter speed system (=storage time/drive control). These systems are used to obtain an image signal with an appropriate S width and bell. For example, if the photographer wants 24 to F8 as the direct range, but the illuminance of the subject is very high, the aperture value will be set to F8 and the accumulation time will be shortened to ensure proper image capture. If the illuminance of the object is very low, the aperture value is set to F4 and the accumulation time is further lengthened to obtain an appropriate imaging signal.

The photographer told me in correspondence that the shutter speed was 1/1000 to 1/1/
If you want 2000 seconds and the illuminance of the subject is very high, the shutter speed or accumulation time will be 1/2000.
seconds, and is further closed by the aperture circuit. When the illuminance of the object is very low, the accumulation time for the shutter speed is 1/10oO seconds9, and the diaphragm circuit is further opened to obtain a proper image signal.

For example, the same operation is performed when the aperture value and shutter speed are not within a certain range but are fixed values as described above. FIG. 2 shows the control operation when the aperture value is fixed. In the same figure,
a, b, c shows the relationship between the subject illuminance, the amount of light incident on the image sensor, the mu/D circuit input signal, and the control operation when the 4d deviation value is not fixed. Similarly &/ , b', c/
shows the relationship between control and wholesale operations when the aperture value is fixed.

If the 1' aperture is not fixed, when the subject illuminance is high, the aperture circuit moves to obtain the appropriate exposure, and the image sensor's storage time remains constant.When the subject illuminance is low, the aperture circuit is fully opened, and then the image is taken. A drive circuit moves the element output signal to control the accumulation time of the image sensor to bring it to an appropriate signal amplitude level. In addition, when the aperture value is fixed, the aperture value is constant regardless of the subject illuminance, so the amount of light incident on the image sensor is shifted in parallel to the subject illuminance toward "lower", and the image sensor output signal is controlled by the drive circuit to When the illuminance is about 5J, the accumulation time is set to "long", and when the illuminance of the subject is high, the accumulation time is set to "short" to control the signal part width level to an appropriate level. The same applies to the case where the shutter speed is fixed, so the explanation will be omitted.

Also, if the aperture value and shutter speed are not specified, the mode control times! 112 and system control circuit 113
By uniquely setting the aperture value and shutter speed according to the illuminance of the subject, the aperture value and shutter speed that can be tolerated under normal conditions are automatically set without worrying about the aperture value and shutter speed. It is possible to obtain a satisfactory imaging signal.

Next, a method of driving the image sensor will be explained.

In this embodiment, a drive circuit 110 for the sensor 103 is controlled by a drive control circuit 111. This control method controls the amplitude level of the output signal of the image sensor by changing the accumulation time of the image sensor.
As shown in FIG.

Figure 3 shows an interline transfer type image sensor (IT-CO).
D) Schematic configuration diagram of a frame interline transfer type image sensor (FIT-(, CD) with a storage section in the configuration, 4th
The figure shows the drift vertical X drive pulse of the image sensor. In the figure, light incident on a photodiode 301 is photoelectrically converted and accumulated. After a certain photoelectric conversion period (accumulation period), the stored five charges are sent to the adjacent VCCD 302, but smear charges remain in vccn. To sweep out this residual charge, a vccpK transfer pulse is applied to the drain section 3.
Sweep out at 03 (T, period). After this operation, the photodiode 301C + signal voltage is connected to V CCD.
302 and then transferred to the storage unit 305 via the transfer gate 304 in a short period (T2 period). The charge d sent to the storage unit 305 is read out to the register 308 for each line.
and are read out sequentially.

FIG. 6 shows the case where the above-mentioned image pickup device is used and the storage time is changed. In the figure, unnecessary charges are transferred to vccn by the first read pulse, and signal charges are accumulated. During this time, unnecessary charges transferred to the VCCD of the imaging section are swept out to the drain section using the horizontal and vertical blanking periods. After a certain signal storage period (T3), the signal charges are transferred to the VCCD of the imaging section and transferred to the storage section (T2).

The signal charges transferred to the storage section are read out line by line, transferred to a register, and read out one by one. During this time, the VCCD of the imaging section is transferring data toward the drain section.

By such driving, the accumulation time can be changed, and the amplitude level of the image sensor output signal can be controlled.

As described above, according to this embodiment, when the aperture value is set by the mode control circuit, the aperture rotation is controlled so as to satisfy the aperture value, and the accumulation time is further controlled to ensure proper imaging. Get the signal and get the aperture priority image. Further, when the shutter speed is set, the accumulation time is controlled to a value that satisfies the shutter speed, and furthermore, the aperture path is controlled to obtain an appropriate imaging signal and an image of the speed destination is obtained. In addition, if there is no specific setting, the image will be obtained at a unique aperture (or direct or shutter speed) that is previously determined according to the subject illuminance. Since the function of the image sensor is used, no special circuit is required. First, it is possible to obtain an image that reflects the photographer's intention with a simple operation, and it is also possible to obtain a good image as a video shot or a still image.

FIG. 6 is a block diagram of an imaging device showing a second embodiment of the present invention. In the figure, the difference from the first embodiment is that 604 is a gain circuit and 608 is a gain control circuit, and the other components are the same as the first embodiment.

Regarding the imaging device of the second embodiment configured as described above, its masterpiece will be explained below, focusing on the points that are different from the first embodiment. In this embodiment, the drive circuit 611 of the image sensor 603
By controlling the drive sterilization circuit 612, the accumulation time of the image sensor is changed to increase the humidity of the output signal of the image sensor, III!
In addition to controlling the level, the output signal of the image sensor is controlled by a gain circuit 8 whose gain is controlled by a gain control circuit 80B.
Therefore, it is controlled to a predetermined value corresponding to the vibration level.

In the block diagram of FIG. 6, when the mode control circuit 613 is not operating, the aperture drive circuit 609, the drive circuit 611, the gain control circuit 608, the signal detection circuit 607, and the system control circuit 614 are operating. After adjusting the light intensity with C operation,
The image sensor is driven to satisfy the requirements such as preventing smear and improving one-hour resolution, and then adjusting the image sensor output signal to obtain an appropriate video signal portion width.

Further, when the mode control circuit 613 is operating, the storage time of the aperture circuit 602 and the image sensor is fixed to the set value,
Drive circuit 611, gain control circuit 608, and signal detection circuit 6
07 and the system control circuit 614 work to change the accumulation time in the image sensor to adjust the actual exposure and drive to satisfy the improvement of time resolution, and the gain control circuit changes the amplitude of the output signal. Adjust A to obtain a proper video signal. Also, when capturing images with a small depth of field and a shallow depth of field, when adjusting the actual exposure amount by controlling the drive of the image sensor, the exposure time is determined by the readout pulse that occurs during the horizontal blanking period, as shown in Figure 6. , it is difficult to control more precisely than during the 1H period, and errors may occur. Therefore, the output signal of the image sensor is then controlled by a gain control circuit to obtain an appropriate video signal.

As described above, according to this embodiment, the aperture value and shutter speed are set arbitrarily or automatically, and the storage time of the aperture circuit and image sensor is controlled in the set state. By controlling the aperture value and obtaining appropriate video/image signals, it is possible to obtain an image that reflects the photographer's intention in terms of the aperture value and shutter speed. Since it is possible to make coarse adjustments with the 2-channel camera and to make fine adjustments with the gain control circuit, the gain control circuit does not need to be narrow, and images that reflect the photographer's intentions can be obtained with a simple circuit configuration. .

Note that the first thing. In the second embodiment, an imaging device that performs digital signal processing including a MU/D circuit has been described, but the invention is not limited to this, and an imaging device that performs analog signal processing may be used. Furthermore, although the signal detection circuit is configured to process the digital signal after the MU/D circuit, it may also be configured to process the analog signal before the MU/D circuit. Average value detection using a signal, peak detection using a peak value of a signal, food output, etc. may be used.

Furthermore, the first. The video signal obtained in the second embodiment is then sent to a signal processing circuit for extended functions such as recording any screen as a still screen on a memory or magnetic floppy, or obtaining a print image using a video printer. Since it is obvious, a special explanation is omitted here.

Further, in the first embodiment, the case where the gain circuit is configured in the analog section before the Mu/D circuit is shown, but it may be configured in the digital section after the Mu/D circuit.

Furthermore, in the second embodiment, the case where FlT-COD is used as the image sensor is shown, but the present invention is not limited to this as long as it is possible to change the accumulation time.

Also, 1st. In the second embodiment, it is clear that operating with a fixed aperture value or shutter speed is the same as switching the aperture value or shutter speed from automatic to manual.

As described in detail, according to the present invention, a photographer can arbitrarily select an aperture value and shutter speed to produce an image with excellent depth of field and temporal resolution, that is, an aperture-priority image and a shutter speed variable. In addition to being able to obtain the original image, it is also possible to automatically set the aperture value and shutter speed for excellent quality, making it possible to create vibrant images that can be used as a video artist or as a still image for printing. This has great practical effects.

[Brief Description of the Drawings] Fig. 1 is a block diagram of an imaging device in an embodiment of the present invention, Fig. 2 is a control operation diagram of the embodiment, and Figs. 3 and 4 are imaging devices used in the embodiment. A schematic configuration diagram of the element and a standard vertical drive pulse diagram, FIG. 5 is a drive diagram of the image sensor when the accumulation time changes, FIG. 6 is a block diagram of an imaging device according to another embodiment of the present invention, and FIG. FIG. 8 is a block diagram of a conventional imaging device, and FIG. 8 is a control operation diagram of the conventional imaging device. 1o1...Lens, 102...Aperture circuit, 103...Image sensor, 104...
Amplifier circuit, 106...Mu/D circuit, 106...
...Signal processing circuit, 107...Signal detection circuit, 108...Fall drive circuit, 109...
...Aperture control circuit, 110...Image sensor drive circuit, 111...Drive control circuit, 112...
...Mode control circuit, 113...System control circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 ht 9'cz Camera element Gokai 1 person figure W4 + Direct drive pulse Figure 5 Accumulation Ginkai barley

Claims (5)

[Claims] (1) An aperture circuit that changes the amount of light incident on the image sensor, an aperture control circuit that controls the aperture circuit, an accumulation time control circuit that controls the accumulation time of the image sensor, and the aperture control circuit and accumulation time control. An imaging device characterized by comprising a mode control circuit that controls the circuit. (2) The accumulation time control circuit is composed of an image sensor drive circuit and a drive control circuit that controls the drive circuit, and controls the amplitude of the output signal of the image sensor to a target level and the time of the output signal of the image sensor. The imaging device according to claim 1, wherein resolution is controlled. (3) Claim 1 or 2, wherein the mode control circuit includes an aperture value designation circuit and an accumulation time designation circuit.
The imaging device described. (4) The imaging device according to claim 1, 2 or 3, wherein the mode control circuit uniquely controls the aperture control circuit and the storage time control circuit in accordance with the illuminance of the subject. (5) an aperture circuit that changes the amount of light incident on the image sensor; an aperture control circuit that controls the aperture circuit; an accumulation time control circuit that controls the accumulation time of the image sensor; the aperture control circuit and the accumulation time; An imaging device comprising: a mode control circuit that controls a control circuit; a gain circuit that amplifies an output signal of the image sensor; and a gain control circuit that controls the gain of the gain circuit.