JP3581374B2 - Imaging device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an imaging apparatus having a sensing unit that performs photoelectric conversion and stores information.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, when a video camera shoots an object and forms a standard television signal from the image of the object, the exposure time of an image pickup device built in the video camera usually has a period (period) of a vertical synchronization signal of the standard television signal. It is set so as to be substantially the same as the time (one field cycle) for one cycle of the field cycle (known field reading).
[0003]
However, depending on the situation to be photographed, the exposure time may be longer than one field period due to lack of illuminance of the subject or the like, or conversely, when photographing a fast-moving subject. In some cases, the exposure time is required to be shorter than one field period in order to prevent the subject image from flowing.
[0004]
In order to satisfy such demands, while devising the timing of reading signals from the image sensor and using an image memory, the exposure time of the image sensor is made longer than one field period, a so-called slow shutter technology, There has been a technique called a high-speed electronic shutter in which the charge of a sensor unit that performs photoelectric exchange during an exposure period of an image sensor is discarded for a certain period to shorten the exposure time of the image sensor than one field period.
[0005]
[Problems to be solved by the invention]
However, the slow shutter function and the high-speed electronic shutter function in the conventional example described above have been treated as separate special functions.
[0006]
FIG. 8A is a diagram for explaining the selection operation of the slow shutter function, and FIG. 8B is a diagram for explaining the selection operation of the high-speed electronic shutter function. As shown in FIG. 8A, from the viewpoint of processing using an image memory, the slow shutter function is treated as the same category as so-called strobe effect and digital still function. As shown in (b), the high-speed electronic shutter function has been treated as an independent function for controlling the accumulation time of the image sensor by itself.
[0007]
Therefore, if the photographer attempts to change the shutter speed from 1/60 seconds (in the case of NTSC) from the low speed side to the high speed side or vice versa, the function for selecting the function of the slow shutter and the high speed Two operation units for selecting functions of the electronic shutter had to be operated.
[0008]
In view of the above-mentioned problem, the present invention allows a photographer to easily and freely operate an operation member for selecting a function of the slow shutter and a function for selecting a function of the high-speed electronic shutter with common operation means. It is an object of the present invention to provide an imaging device capable of selecting a shutter speed.
[0009]
[Means for Solving the Problems]
In order to solve the conventional problems, to achieve the object, a plurality of photoelectric conversion units that receive light and perform photoelectric conversion, and an output unit that outputs image information accumulated in the photoelectric conversion unit, By applying a read pulse, an imaging unit having a transfer unit for transferring image information from the photoelectric conversion unit to the output unit, such that the exposure period of the imaging unit is a first period, A driving unit for driving the imaging unit so as to accumulate image information in the imaging unit by applying the read pulse to the transfer unit in the first period cycle. Means for transferring the signal of the photoelectric conversion unit to the output unit by applying the read pulse to the transfer unit so that the exposure period is longer than the first period, and Without adding the read pulse to the transfer means after the lapse of the period, the first addition after the elapsed period, a first motor for driving the read pulse after a second time period to apply to the transfer means - de When the so exposure period is shorter than the first period, driving the in first third period of the period, as the electronic shutter operation sweeping the image information by the photoelectric conversion portion A second mode, wherein the image pickup apparatus further includes a first exposure period shorter than the first period and a first operation period of the operator when the exposure period is set longer. And the second operation of the operator when the exposure period is set to be longer in a period in which the exposure period extends over a period shorter than the first period and a period longer than the first period. Operation and the exposure period is the first period The third operation of the operator in the case of setting the exposure time longer in a longer period can be performed by the same operation on a common member, and the exposure period is longer than the first period. In the fourth operation of the operator when the exposure period is set to be short, the exposure period is set in a range that extends over a period longer than the first period and a period shorter than the first period. A fifth operation of the operator when setting the exposure period to be short, and an operator when setting the exposure period to be short so that the exposure period is shorter than the first period. Operating means for enabling the sixth operation to be performed by the same operation on a common member; and, when the first operation is performed, driving the driving means in the second mode, The same operation as the operation 1 and the same member as in the case where the first operation is performed. When the second operation, which is an operation, is performed, first, the driving unit is driven in the second mode, and then, the driving unit is switched to be driven in the first mode. When the third operation, which is the same operation as the first and second operations and the operation of the same member as when the first and second operations are performed, is performed, the driving unit is set to the first driving mode. When the fourth operation is performed, the driving unit is driven in the first mode, and the same operation as the fourth operation and the fourth operation are performed. When the fifth operation, which is an operation with the same member as that described above, is performed, first, the driving unit is driven in the first mode, and then the driving unit is driven in the second mode. So that the same operation as the fourth and fifth operations and the And control means for controlling the driving means to drive in the second drive mode when the sixth operation, which is an operation with the same member as in the case of performing the operation of 5, is performed. It is characterized by the following.
[0010]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
1 to 3 show an embodiment according to the present invention, FIG. 1 is a block diagram showing a configuration of a video camera which is an embodiment of the present invention, and FIG. 2 is a diagram for explaining operations in the present embodiment. FIG. 3 illustrates an example of an operation unit according to the present exemplary embodiment. 4 is a conceptual diagram of a CCD, FIG. 5 is a timing diagram and a schematic diagram of signals of various parts during operation of a slow shutter function, and FIG. 6 is a cross-sectional view and a potential diagram along line AA ′ in FIG. FIG. 7 is a schematic diagram of signals at various parts for explaining the operation of the high-speed electronic shutter.
[0012]
First, the operation of the above-described slow shutter and high-speed electronic shutter will be described with reference to FIGS. 1, 4, 5, 6, and 7. In FIG. 1, reference numeral 1 denotes a CCD, which is an image pickup device that performs photoelectric conversion, and has a structure as shown in FIG. 4, for example.
[0013]
FIG. 4 shows a schematic structure of a so-called interline transfer type CCD, wherein 10 is a sensor unit for performing photoelectric conversion, 11 is a vertical transfer register, 12 is a horizontal transfer register, and 13 is an output amplifier.
[0014]
Reference numeral 2 denotes a drive circuit for driving the CCD 1, reference numeral 3 denotes a synchronizing signal generator for generating various synchronizing signals necessary for generating a standard television signal, and reference numeral 4 denotes a signal from the synchronizing signal generator 3. And a timing control device for controlling the drive timing of the CCD 1 and the timing for controlling the exposure (charge accumulation) time. Reference numeral 5 denotes a signal processing circuit for forming a luminance signal (Y) and a color difference signal (RY, BY) from the signal output from the CCD 1. The output signal output from the signal processing circuit 5 is A / A. The A / D conversion is performed by the D conversion device 6 into a format suitable for storing the image signal, and then the output and the storage unit in the device are performed by the image memory device 7 according to the control signal output from the timing control device 4. Is stored. Reference numeral 8 denotes a D / A converter for D / A converting an output signal output from the image memory device 7, and 9 denotes a luminance signal (Y ') and a color difference signal ((R) output from the D / A converter 8. −Y) ′, (BY) ′), an encoder device for forming a standard television signal, and 21 is a shutter speed selection operation unit.
[0015]
When the photographer selects the shutter speed corresponding to the slow shutter using the shutter speed selecting operation section 21, the slow shutter operates as follows. FIG. 5 is a timing chart of transfer of accumulated charges and output of an image signal when the exposure time of the CCD 1 is set to about two field periods by using a so-called slow shutter, and a schematic diagram of signals of respective units. In FIG. 5, φROG is a read timing for transferring the charges accumulated in the sensor unit 10 to the vertical transfer register 11, and the vertical synchronization signal VD is a timing serving as a source of φROG. As shown in FIG. 5, since the exposure time of the CCD 1 is set to about two field periods, the φROG pulse is applied only once in two fields, so that the electric charge of the sensor unit 10 is reduced to about two fields when the time t0 is a starting point. After being accumulated for a period, it is moved to the vertical transfer register 11 at time t1. Thereafter, the electric charge is transferred to the horizontal transfer register at a predetermined timing, and is output to the signal processing circuit 5 through the output amplifier 13.
[0016]
Here, in one field period (B1 period) immediately after the φROG pulse is applied, the electric charge accumulated in the sensor unit 10 from time t0 to time t1, that is, the electric charge accumulated for about two field periods is output to the output amplifier. 13 (SB1), but in the next one field period (B2 period), no φROG pulse is applied, so that an empty signal is output.
[0017]
Therefore, the A / D converter 6 is driven by the timing control device 4 shown in FIG. 3 immediately after the generation of the φROG pulse, and the image corresponding to the electric charge output from the signal processing circuit 5 and accumulated for about two fields. The signal is stored in the image memory device 7 and simultaneously transmitted to the D / A converter 8 (B1 period). Then, in the next one field (B2 period), the image memory device 7 outputs the signal stored in the image memory device 7 in the B1 period to the D / A converter 8 (B2 period). Therefore, as shown in FIG. 5, the same signal is transmitted to the D / A converter 8 continuously for two fields, D / A converted, and output. The above is the operation of the slow shutter in the present embodiment.
[0018]
Next, a so-called electronic shutter will be described. FIG. 6 is a sectional view and a potential diagram along the line AA ′ in FIG. In FIG. 6, reference numeral 14 denotes a channel stop (CS) for separating pixels, and 15 denotes a readout gate (ROG) for transferring the electric charge accumulated in the sensor unit 10 to the vertical transfer register 11. When the photographer selects the shutter speed corresponding to the high-speed electronic shutter using the shutter speed selection operation section 21, the high-speed electronic shutter operates as follows. FIG. 7 is a diagram showing the drive timing of each unit for one field of the standard television signal and the substantial accumulation time of the sensor unit 10 at the time of the high-speed electronic shutter. φROG is a charge readout pulse applied to the readout gate 15. When the logic level is “H”, the potential of the readout gate 15 decreases, and the charge of the sensor unit 10 is transferred to the vertical transfer register 11. φSUB is a charge removal pulse applied to the substrate (substrate) 16. When the logic level is “H”, the potential wall in the substrate 16 drops, and the charge accumulated in the sensor unit 10 flows into the substrate 16. , ΦSUB terminal 19 to the outside (removed).
[0019]
In FIG. 7, φROG is in a vertical blanking period (not shown), and φSUB is in a horizontal blanking period (not shown). In the CCD 1, the charge of the sensor unit 10 is transferred to the vertical transfer register 11 by setting φROG = “H” at time t10, and then the next charge accumulation period starts, but during the horizontal flyback period until time t11. , ΦSUB = “H”, so that the charge is swept out from t10 to t11 and does not remain in the sensor unit 10. Further, since φSUB = “L” from time t11 to t12, the charges generated in the sensor unit 10 during this period are accumulated, and are transferred to the vertical transfer register 11 when φROG = “H” at time t12. After all, the substantial exposure time in this case is (t12-t11), which is the shutter speed. Then, by controlling the φSUB pulse, it is possible to arbitrarily change a period (t12-t11) in which electric charges are accumulated in the sensor unit 10, that is, a shutter speed.
[0020]
Next, an example in which the function selection device including the shutter speed selection operation unit 21 in this embodiment is specifically realized will be described with reference to FIGS. As shown in FIG. 2, the shutter speed selection operation unit 21 treats the slow shutter and the high speed shutter as the same category, so that the photographer sets the shutter speed to 1/60 second (NTSC Only when the shutter speed selection operation unit 21 is operated to change from the low-speed side to the high-speed side or vice versa after the case (2). FIG. 3 shows a function selection device including a shutter speed selection operation unit 21. 31 is an exterior member including a part of the operation unit in the video camera, 33 is a selection dial for selecting detailed contents of the function selected by the function selection button 32, and is selected by the function selection button 32 and the selection dial 33. The selection status of each function is displayed on the display device 34. Here, the function selected by the function selection button 32 includes, for example, an autofocus function, a zoom function, a shutter speed function, and the like. A function selection index 35 moves to indicate the function name selected by the function selection button 32 among the function names displayed on the function name display section 36. Reference numeral 37 denotes a detailed content display portion for displaying the detailed content of each function selected by the selection dial 33. For example, in the detailed content display portion 37, a portion next to the display of the shutter speed function of the function name display portion 36 is provided. Indicates a shutter speed such as 1/60 or 1/100.
[0021]
In the present embodiment, the selection dial 33 is generally called an incremental rotary encoder, and generates a two-phase pulse by rotating it. The two-phase pulse is generated by appropriate binary logic means (not shown). , The rotation phase, rotation speed, and rotation direction of the selection dial 33 can be obtained. Further, when changing the details of the function selected by the selection button 32 with the selection dial 33, the binary logic means changes the rotation phase, the rotation speed and the rotation direction, and the change of the display of the detailed contents display section 37. Relationships can be set independently for each function. For example, when the zoom function is selected by the function selection button 32, the rotation of the selection dial 33 causes the detailed content display section 37 about the zoom function to display × 2, × 4, × 10. . . As described above, when the shutter speed function is selected by the function selection button 32, the rotation of the selection dial 33 causes the detailed content display section 37 for the shutter speed function to display 1 /. 60, 1/100, 1/250. . . And the display of the shutter speed changes.
[0022]
Here, assuming that the shutter speed is currently 1/250 second, the operation of resetting the shutter speed to 1/30 second from this state will be described step by step.
[0023]
First, in order to select a shutter item displayed on the function name display section 36, the function selection button 32 is pressed, and the function selection index 35 is moved to the position of the shutter item. In this state, the selection by the selection dial 33 is effective only for setting the shutter speed. FIG. 2 shows how the binary logic means changes the shutter speed when the selection dial 33 is turned clockwise and counterclockwise. Here, for example, the selection dial is shown. Turning the dial 33 clockwise changes the shutter speed to a higher speed side, and turning it counterclockwise changes the shutter speed one step at a time, but does not change it if the rotation speed is less than a certain rotation phase. Further, when the shutter speed reaches 1 / 10,000 seconds of the highest speed or 1/8 seconds of the lowest speed, the shutter speed does not change even if it is further turned clockwise and counterclockwise. To change the shutter speed from 1/250 sec. To 1/30 sec., Turn the selection dial 33 counterclockwise until the display on the detailed content display section 37 becomes 1/30. With such an operation, the operation of resetting the shutter speed from 1/250 second to 1/30 second is completed.
[0024]
In the above-described embodiment, in the slow shutter function, the image of the previous field is stored in the memory, and the same image is output continuously for two fields. According to this method, the charge accumulation period can be extended to about two field periods. . However, besides this, for example, the charge accumulation period is determined to be up to one field period, the CCD is read out for each field, the image signal of the previous field is stored in a digital memory or the like, and the current signal is stored. The present invention is also applicable to a case where the shutter speed is reduced by a method of outputting an average value as an image signal in addition to the image signal.
[0025]
In the above-described embodiment, the selection dial 33 is used as a means for changing the shutter speed. Alternatively, for example, a shutter speed may be assigned to each of a plurality of push buttons, and a selection may be made from among them. Alternatively, a configuration may be employed in which two push buttons such as a plus key and a minus key are used and the shutter speed is sequentially changed to a high speed side and a low speed side with respect to the current shutter speed.
[0026]
Further, in the above-described embodiment, when the maximum speed reaches 1 / 10,000 seconds and the re-low speed reaches 1/8 seconds, the shutter speed does not change even if the selection dial 33 is turned further right and left, respectively. Although the configuration has been described, a configuration capable of changing from the highest speed to the lowest speed or vice versa may be employed.
[0027]
【The invention's effect】
As is clear from the above description, the present invention has the following effects.
(1) The photographer can very easily and freely select a shutter speed without troublesome operation.
(2) The space occupied by the operation means is reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of a video camera that is an embodiment of the present invention.
FIG. 2 is an explanatory diagram of an operation in the embodiment of FIG. 1;
FIG. 3 is a diagram showing a function selection device including a shutter speed selection operation unit in the embodiment of FIG. 1;
FIG. 4 is a diagram showing a schematic structure of a CCD.
FIG. 5 is a timing chart in a slow shutter and a schematic diagram of signals of respective units.
FIG. 6 is a sectional view and a potential diagram of a CCD.
FIGS. 7A and 7B are schematic diagrams of signals of respective sections for explaining the operation of the high-speed electronic shutter.
FIG. 8 is an explanatory diagram of a conventional technique.
[Explanation of symbols]
1 CCD
Reference Signs List 10 Sensor unit 11 Vertical transfer register 12 Horizontal transfer register 16 Substrate 21 Shutter speed selection operation unit

Claims (4)

A plurality of photoelectric conversion units that receive light and perform photoelectric conversion, an output unit to which image information accumulated in the photoelectric conversion unit is output, and a readout pulse are applied to convert image information from the photoelectric conversion unit. Imaging means having a transfer means for transferring to the output unit; and applying the readout pulse to the transfer means in the first period cycle so that an exposure period of the imaging means is a first period. A driving unit for driving the imaging unit so as to store image information in the imaging unit,
The driving unit transfers the signal of the photoelectric conversion unit to the output unit by applying the read pulse to the transfer unit so that the exposure period is longer than the first period. A first mode in which the read pulse is not applied to the transfer means after a lapse of one period , and the read pulse is applied to the transfer means after a lapse of a second period after the lapse of the first period. de and such that said exposure period is shorter than the first period, the in third period of the first period, driving as sweeping the image information by the photoelectric conversion unit by the electronic shutter operation And a second mode of
The imaging apparatus may further include a period in which the exposure period is shorter than the first period,
A first operation of the operator when the exposure period is set to be longer, and a period in which the exposure period spans a period shorter than the first period and a period longer than the first period. The second operation of the operator when the exposure period is set to be longer, and the third operation of the operator when the exposure period is set to be longer than the first period when the exposure period is longer than the first period. And the fourth operation of the operator in the case where the exposure period is longer than the first period and the exposure period is set shorter. A fifth operation of the operator when the exposure period is set to be shorter in a range where the exposure period spans a period longer than the first period and a period shorter than the first period; The exposure period is shorter than the first period, and the exposure period is shorter. Sixth operation and the operator when to continue to set the operating means for enabling the same operation in a common member,
When the first operation is performed, the driving unit is driven in the second mode, and the same operation as the first operation and operation with the same member as when the first operation is performed is performed. When the second operation is performed, first, the driving unit is driven in the second mode, and then the driving unit is switched to be driven in the first mode. When the third operation, which is the same operation as the above operation and the same operation as the case where the first and second operations are performed, is performed, the driving unit is driven in the first driving mode. When the fourth operation is performed, the driving unit is driven in the first mode, and the same operation as that of the fourth operation and the same member as when the fourth operation is performed. When the fifth operation, that is, the operation described above, is performed, first, the driving is performed. Driving the means in the first mode, and then switching the driving means to drive in the second mode, and performing the same operations as the fourth and fifth operations and the fourth and fifth operations. Control means for controlling the driving means to be driven in the second drive mode when the sixth operation, which is an operation with the same member, is performed;
An imaging device comprising: 2. The imaging apparatus according to claim 1, wherein the operation unit is a rotatable member, and when turned to one side, the exposure period becomes shorter, and when turned to the other side, the exposure period becomes longer. 3. . The imaging apparatus according to claim 1, wherein the operation unit includes a selection unit for extending the exposure period and a selection unit for shortening the exposure period. A function selection unit capable of selecting a plurality of functions including an autofocus setting function, a zoom setting function, and the exposure period setting function; and a display unit for displaying the selected function. The imaging apparatus according to claim 1, wherein each function is operated by the operation unit.

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