JP4838460B2 - Imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus such as an electronic still camera provided with electronic shutter means. In place Related.
[0002]
[Prior art]
As is well known, the electronic still camera is instantaneously moved from the optical axis position to a position off the optical axis position in response to a release operation, and returns to the original optical axis position when the shutter is closed. A mechanical shutter means having a mirror means (quick return mirror), a front blade that opens the light receiving surface of the imaging means, and a rear blade that shields the light receiving surface of the imaging means, and a CCD (charge) that is the imaging means Some devices include an electronic shutter unit that adjusts an exposure amount by changing a charge storage time of a charge storage element such as a coupled device, and a diaphragm unit that adjusts the amount of light incident on the CCD.
[0003]
In addition, in the case of such an electronic still camera, a timer (this timer is used as a release stabilization timer) to keep a constant time (this time is referred to as a release time lag) from the start of the release operation to the actual start of exposure. Are provided).
[0004]
FIG. 7 is a time chart of a release sequence from the release to the end of exposure in an electronic still camera equipped with a conventional electronic shutter.
[0005]
In the figure, when the switch (SW2), which is a release operation, is turned on, the mirror means (quick return mirror) instantaneously moves from the optical axis position to a position off the optical axis position in response to the switch (SW2). Move (this is called mirror up). At the same time, the diaphragm means starts to drive the diaphragm, and the release stabilization timer starts.
[0006]
Then, after the aperture driving is finished, the leading blade running operation of the mechanical shutter means is started. After a certain period of time, the leading blade running operation is completed, and when the release stabilization timer expires, the CCD The electronic shutter means starts driving (accumulation starts).
[0007]
After the electronic shutter means is driven for a predetermined time (set shutter time), when the rear blade of the mechanical shutter means travels and the light receiving surface of the CCD, which is the imaging means, is shielded, the normal reading operation as the transfer process is performed. Be started.
[0008]
As described above, during the transfer process, the light receiving surface of the CCD is completely shielded from light, so that extra light is not applied to the CCD, so that it is possible to reduce the occurrence of problems such as smear.
[0009]
Further, conventionally, the traveling operation of the leading blade of the mechanical shutter means is started simultaneously with the mirror-up operation, and when the mirror-up operation and the aperture driving operation are completed, the electronic shutter device is started to drive, and the electronic shutter device is operated for a predetermined time ( It has also been proposed that the transfer process is started when the rear blade of the mechanical shutter means travels and the light receiving surface of the CCD is shielded after driving (set shutter speed) (Japanese Patent Laid-Open No. 9-218434). Publication).
[0010]
[Problems to be solved by the invention]
However, the electronic shutter unit that causes the leading blade of the mechanical shutter unit to travel after completion of aperture driving of the aperture unit as in the above-described conventional example has the following problems.
[0011]
That is, the time during which the aperture means can be driven during the release stabilization timer is shortened by the time from when the leading blade of the mechanical shutter means starts running until it is completely terminated.
[0012]
In particular, in a camera that uses a motor to drive the aperture means, it is difficult to increase the speed as in the case of a spring drive. Therefore, in such a camera, the number of possible aperture stops of the aperture means in the release stabilization timer is reduced. Will end up. Therefore, in this case, the depth of field becomes shallow, and it is difficult to take a photograph in focus with a fast-moving subject or the like.
[0013]
Further, by extending the release stabilization timer, it is possible to increase the number of stages that can be driven in the timer. However, in this case, since the time from the release to the actual shooting is increased, there is a problem that a decisive moment of shooting is missed in a fast-moving subject or the like.
[0014]
In addition, in the camera disclosed in Japanese Patent Laid-Open No. 9-218434, which is the conventional example, after the release operation, the mirror-up operation is started, and at the same time, the traveling operation of the leading blade of the mechanical shutter means and the driving of the diaphragm means are started. As described above, it is possible to avoid the problem that the driving time of the diaphragm means is reduced by the traveling time of the leading blade.
[0015]
However, since the mirror up time and the driving time of the aperture means are usually longer than the travel time of the front blade, the travel motion of the front blade is not possible in the camera disclosed in the above-mentioned conventional example, Japanese Patent Laid-Open No. 9-218434. Since the time until the mirror up and the driving of the aperture means are completed after the completion of the process is continued, the CCD continues to irradiate light, which causes problems such as smear.
[0016]
The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to enable narrowing down in the release time lag while suppressing deterioration in image quality when imaging using the electronic shutter means. Imaging device that can increase the number of steps and eliminate problems such as smear Place Is to provide.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, Imaging device In response to the release operation and the imaging means for imaging the subject light Aperture Start working, By completing the aperture operation when the set aperture operation time has elapsed A diaphragm means for adjusting a subject light quantity incident on the imaging means; When a longer period of time elapses when the release stabilization timer time that is set in advance as the time from when the release operation is performed to when the imaging operation by the imaging unit is started is compared with the aperture operation time An electronic shutter means for supplying an imaging start signal to the imaging means to start an imaging operation; A light-shielding unit that shields the light-receiving surface of the image-capturing unit, starts opening the light-shielding unit when a predetermined time has elapsed since the release operation is performed, and starts the imaging operation by the electronic shutter unit. Mechanical shutter means for driving the light shielding means so that the opening operation is completed, and the opening operation of the light shielding means is started before the aperture operation is completed. .
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0021]
(First embodiment)
First, a first embodiment of the present invention will be described with reference to FIGS.
[0022]
FIG. 1 is a diagram illustrating a configuration of an electronic still camera that is an imaging apparatus according to the present embodiment.
[0023]
In the figure, reference numeral 20 denotes a central processing unit (hereinafter referred to as MPU) of a microcomputer as camera control means built in the camera body. The MPU 20 includes an AF (autofocus) drive circuit 12, an aperture drive circuit 13, a mirror drive circuit 14, a focus detection circuit 16, a shutter drive circuit 17, a CCD drive circuit 18, a video signal processing circuit 9, a switch sense circuit 21, and photometry. A circuit 23 is connected. The MPU 20 controls each element and each circuit sequentially in a predetermined order.
[0024]
The AF drive circuit 12 is configured by, for example, a stepping motor, and focuses on the CCD 7 by changing the focus lens position in the photographing lens unit 1 under the control of the MPU 20. The aperture drive circuit 13 is configured by, for example, an auto iris or the like, and changes the aperture 2 described later under the control of the MPU 20 to change the optical aperture value.
[0025]
The diaphragm 2 and the diaphragm drive circuit 13 constitute diaphragm means.
[0026]
A main mirror 4 guides the subject image formed by the photographic lens unit 1 to the pentaprism 3, transmits part of the image, and guides it to the focus detection sensor 15 through the submirror 5. The mirror drive circuit 14 is configured to be movable between a position where the subject image can be observed with the viewfinder and a retreat position where the subject image is retracted from the optical path of the subject light beam during photographing.
[0027]
Reference numeral 5 denotes a sub mirror that reflects subject light transmitted through a part of the main mirror 4 and guides the subject image to the focus detection sensor 15. The sub mirror 5 is linked with the main mirror 4 or the mirror drive circuit 14 of the main mirror 4, and when the main mirror 4 is at a position where the subject image can be observed with the viewfinder, the subject light is sent to the focus detection sensor 15. And a position retracted from the optical path of the subject light beam at the time of photographing (a retracted position).
[0028]
The mirror drive circuit 14 is composed of, for example, a DC motor and a gear train, and drives the main mirror 4 and the sub mirror 5 under the control of the MPU 20.
[0029]
The main mirror 4, the sub mirror 5, and the mirror drive circuit 14 constitute a mirror means.
[0030]
Reference numeral 3 denotes a pentaprism, which is an optical member that converts and reflects a subject image guided by the main mirror 4 into an erect image.
[0031]
The subject luminous flux that has passed through the photographic lens unit 1 passes through the diaphragm 2, is reflected by the main mirror 4, is guided to the pentaprism 3, and observes the subject image at an eyepiece (not shown). The subject luminous flux that has passed through the photographing lens unit 1 is further guided to the photometric sensor 22. The light beam transmitted through the main mirror 4 is reflected by the sub mirror 5 and re-imaged on the detection surface of the focus detection sensor 15 disposed at a position substantially equivalent to the light receiving surface of the CCD 7. The optical image is converted into an electrical image signal and supplied to the focus detection circuit 15. The focus detection circuit 16 performs accumulation control and readout control of the focus detection sensor 15 according to the signal of the MPU 20 and outputs pixel information to the MPU 20.
[0032]
The MPU 20 performs focus detection calculation by a well-known phase difference detection method based on the image signal of the subject image from the focus detection circuit 16, and establishes an imaging plane by the photographing lens unit 1 and a scheduled imaging plane such as a film plane. The difference, that is, the defocus amount and the defocus direction are obtained. Then, the MPU 20 changes the focus lens position in the photographic lens unit 1 via the AF drive circuit 12 based on the calculated defocus amount and defocus direction, and drives to the in-focus position.
[0033]
Reference numeral 6 denotes a mechanical shutter device that intercepts the subject light flux during finder observation, and retracts from the optical path of the subject light flux according to the release signal during imaging, and the optical path of the subject light flux during finder observation, and starts exposure. The focal plane shutter has a rear blade (a rear blade group) that shields the subject light beam at a predetermined timing after the front blade starts to travel during imaging. The mechanical shutter device 6 is controlled by a shutter drive circuit 17 that has received a command from the MPU 20.
[0034]
The mechanical shutter device 6 and the shutter drive circuit 17 constitute mechanical shutter means, and the MPU 20 and the shutter drive circuit 17 constitute mechanical shutter control means.
[0035]
In this embodiment, the case of having both the front blade and the rear blade has been described. However, when exposure is started with only one shielding member, the subject light beam is retracted from the optical path and photographed. It is also possible to return to the position where the optical path of the subject luminous flux is blocked again after the end of the step.
[0036]
The CCD drive circuit 18 controls charge accumulation and charge transfer of the CCD 7 based on a command from the MPU 20. Reference numeral 7 denotes a solid-state imaging device (CCD) that captures a subject image formed by the photographing lens unit 1 and converts it into an electrical signal. As this solid-state image sensor 7, a CCD, which is a known two-dimensional imaging device, is used. There are various types of imaging devices such as a CCD type, a MOS type, and a CID type, and any type of imaging device may be adopted. In this embodiment, a photoelectric conversion element (photosensor) is used. An interline CCD image pickup device that is two-dimensionally arranged and outputs signal charges accumulated in each photosensor via a vertical transfer path and a horizontal transfer path is employed.
[0037]
The CCD 7 has a so-called electronic shutter function for controlling the accumulation time (shutter time) of charges accumulated in each photosensor. An A / D converter 8 converts an analog output signal from the CCD 7 into a digital signal.
[0038]
The CCD 7, the A / D converter 8, and the CCD drive circuit 18 constitute an image pickup means.
[0039]
Reference numeral 9 denotes a video signal processing circuit which takes charge of overall image processing by hardware such as white balance adjustment, gamma / knee processing, filter processing, and monitor display information synthesis processing on digitized image data of the CCD 7. The monitor display image data from the video signal processing circuit 9 is displayed on the liquid crystal monitor 19 via a liquid crystal driving circuit (not shown).
[0040]
The image data corrected by the video signal processing circuit 9 is subjected to data compression processing by the compression circuit 10 and then stored in the memory card 11.
[0041]
Note that the image data corrected by the video signal processing circuit 9 may be directly stored in the memory card 11 without providing the compression circuit 10.
[0042]
The switch sense circuit 21 controls each part according to the operation state of each switch.
Reference numeral 22a denotes a first switch (SW1) that is turned on when a release button (not shown) is half-pressed. A second switch (SW2) 22b is turned on when the release button is fully pressed. When the second switch (SW2) 22b is turned on, the release operation is started. The release button is provided outside the electronic still camera.
[0043]
The photometric circuit 23 outputs an output from the photometric sensor 22 to the MPU 20 as a luminance signal of each area in the screen. The MPU 20 performs A / D conversion on the luminance signal and adjusts the exposure for shooting.
[0044]
Next, the operation of the electronic still camera according to the present embodiment shown in FIG. 1 will be described with reference to FIGS.
[0045]
2 and 3 are flowcharts showing a flow of operations of the electronic still camera according to the present embodiment.
[0046]
In FIG. 2, first, when a power switch (not shown) is turned on in step S201, the electronic still camera enters a standby state for photographing.
[0047]
Next, in step S202, it is determined whether or not the first switch (SW1) 22a, which is a half-press operation of the release button, is turned on. If it is determined that it is turned on, photometry is performed in step S203, and at the same time, distance measurement is performed by the focus detection circuit 16 in step S204. Based on the result, the photographing lens unit 1 is measured in step S205. The lens drive is started.
[0048]
After the processing of step S203 and step S205 is completed, the aperture value (Av value) and imaging time (Tv value) corresponding to each shooting exposure mode are selected according to the shooting exposure mode selected by a shooting mode selection switch (not shown). ) Is made (steps S206 to S213).
[0049]
That is, in step S206, it is determined whether or not the photographing exposure mode is the Av priority mode. If the Av priority mode is determined, the Av value is an arbitrary value selected by the photographer, the process proceeds to step S210, and the Tv value is determined in accordance with the photometric value measured in step S203. Thereafter, the process proceeds to step S214.
[0050]
On the other hand, if it is determined in step S206 that the mode is not the Av priority mode, the process proceeds to step S207, where it is determined whether or not the photographing exposure mode is the Tv priority mode. If it is determined that the Tv priority mode is selected, the Tv value becomes an arbitrary value selected by the photographer, the process proceeds to step S211 and the Av value is determined in accordance with the photometric value measured in step S203. Thereafter, the process proceeds to step S214.
[0051]
On the other hand, if it is determined in step S207 that the photographic exposure mode is not the Tv priority mode, the process proceeds to step S208 to determine whether the photographic exposure mode is the program mode. If it is determined that the program mode is selected, the process proceeds to step S212, where each Av value and Tv is determined from a program diagram (not shown) set in advance in the camera in accordance with the photometric value measured in step S203. After the value is determined, the process proceeds to step S214.
[0052]
Note that various patterns can be considered as the program diagram, but basically the same flow is passed regardless of whether there is a single pattern or a plurality of patterns.
[0053]
On the other hand, if it is determined in step S208 that the current mode is not the program mode, the process proceeds to step S209 to execute the manual mode (the shooting exposure mode is manual exposure). In the next step S213, the Tv value and Av value are This is an arbitrary value selected based on the photometric value measured in step S203. After the process of step S213 is completed, the process proceeds to step S214.
[0054]
As described above, regardless of which mode is selected, the Tv value (target imaging time) and Av value to be controlled by the processing up to step S213 are determined.
[0055]
Next, in step S214, it is determined whether or not the second switch (SW2) 22b that is turned on by the full pressing operation of the release switch is turned on. If it is determined not to be turned on, the process returns to step S202. If it is determined to be turned on, the process proceeds to step S215 in FIG.
[0056]
In FIG. 3, in step S <b> 215, the mirror drive circuit 14 performs control to mirror up the main mirror 4 and the sub mirror 5. Next, in step S216, the aperture driving circuit 13 starts driving the aperture 2 so that the Av value determined until step S213 in FIG. At the same time, the operation of the aperture driving time: T2 timer is started.
[0057]
Here, a setting method of the T2 timer will be described with reference to FIG.
[0058]
FIG. 4 is a diagram showing a table showing the relationship between the number of aperture stages and the aperture driving time depending on the number of aperture stages. The contents of the table shown in FIG. 4 are recorded in the MPU 20, and as described above, the number of aperture stages determined up to step S213 in FIG. 2 is collated with FIG. 4, and the aperture driving time: T2 is set. Then, the operation of the T2 timer is started.
[0059]
Here, the relationship between the number of aperture stages and the aperture drive time is obtained from the table shown in FIG. 4, but the present invention is not limited to this. For example, a relational expression between the aperture stage number and the aperture drive time is created. Thus, it may be calculated from this relational expression.
[0060]
Returning to FIG. 3 again, the operation from step S217 to step S223 will be described in detail with reference to FIG.
[0061]
FIG. 5 is a time chart showing the operation timing after the release start “after the second switch (SW2) 22b is turned on” in the electronic still camera according to the present embodiment.
[0062]
As already described, when the second switch (SW2) 22b is turned on, the operation of the release stabilization timer: T1 starts. At the same time, the mirror up and the aperture stop 2 are also driven.
[0063]
Further, the number of diaphragm stages of the diaphragm 2 that has already been determined is collated with the table shown in FIG. 4, the diaphragm driving time: T2 is set, and the operation of the T2 timer is started.
[0064]
Next, the MPU 20 compares T1 and T2, and selects whichever is longer. In the case of FIG. 5, T1 is longer, so T1 is selected.
[0065]
Next, the MPU 20 obtains a shutter start timer: T4 at (T1-T3).
[0066]
Here, T3 is the shutter driving time, and is a time determined by (leading blade time lag) + (curving speed of leading blade) as shown in FIG.
[0067]
The leading blade time lag is the actual opening of the main body opening portion (hereinafter referred to as aperture) after the leading blade of the mechanical shutter device 6 starts to be driven by the leading blade travel start signal from the shutter driving circuit 17. It is time to start doing. The curtain speed of the leading blade is the time for the leading blade to travel through the aperture.
[0068]
After T4 time calculated in this way, the leading blade starts traveling by the leading blade traveling start signal from the shutter driving circuit 17, and the shutter driving time: T3 timer starts operation. Then, after the shutter drive time T3 has elapsed (the leading blade is completely open), the CCD drive circuit 18 drives the CCD 7 to start the charge accumulation operation (drive of the electronic shutter means starts).
[0069]
In this manner, the start of the leading blade is controlled by the timer so that the driving is started (overlapped) while the diaphragm 2 is being driven. Accordingly, it is possible to increase the time during which the diaphragm drive can be performed during the release time lag as compared with the conventional case by the amount of time for the overlap.
[0070]
Next, the accumulation operation is performed for a predetermined time with the Tv value determined based on the exposure control value, and the rear blade of the mechanical shutter means 6 travels in accordance with the rear blade travel start signal from the shutter drive circuit 17 in accordance with the end timing. The operation is started, and the light receiving surface of the CCD 7 is set in a light shielding state.
[0071]
The CCD 7 transfers the signal charge accumulated in the photoelectric conversion element to the vertical transfer CCD at the end of the charge accumulation time, and performs normal reading, which is the signal charge reading operation, at the timing of the trailing blade driving end. End the sequence.
[0072]
The process returns to step S217 in FIG.
[0073]
In step S217, as already described, the timer times of the release stabilization timer: T1 and the aperture driving time: T2 are compared, and the longer one is selected. Then, the process proceeds to the next step S218.
[0074]
In step S218, a mechanical shutter start timer: T4 is calculated from the timer selected in step S217 and the shutter driving time T3 already described, and the operation of the T4 timer is started.
[0075]
Next, the process proceeds to step S219, where it is determined whether or not the T4 timer has timed out. If it is determined that the time is up, the process proceeds to the next step S220.
[0076]
In step S220, the shutter drive circuit 17 outputs a leading blade travel start signal, and starts the traveling operation of the leading blade of the mechanical shutter device 6. At the same time, the operation of the shutter driving time T3 timer is started.
[0077]
Next, the process proceeds to step S221, and it is determined whether or not the T3 timer has timed out until the time is up. If it is determined that the T3 timer has expired (the leading blade has been completely opened), the process proceeds to the next step S222.
[0078]
In step S222, the CCD drive circuit 18 operates the CCD 7 to start the accumulation operation. After controlling the charge accumulation time based on the Tv value determined by step S213 in FIG. 2, the process proceeds to the next step S223. .
[0079]
In step S223, the shutter drive circuit 17 outputs a rear wing travel start signal to the mechanical shutter device 6 to drive the rear wing in accordance with the accumulation end timing, drives the rear wing, sets the light receiving surface of the CCD 7 in a light-shielded state, The process proceeds to step S224.
[0080]
In step S224, the mirror drive circuit 14 starts mirror-down according to a command from the MPU 20, and the aperture drive circuit 13 drives the aperture 2 to open. At the same time, the CCD 7 transfers the signal charge accumulated in the photoelectric conversion element to the vertical transfer CCD at the end of the charge accumulation time, and performs normal reading as a signal charge reading operation at the timing of the trailing blade driving end.
[0081]
Next, the process proceeds to step S225 to perform image processing, and after recording in the memory card 11 in the next step S226, the process proceeds to step S217 to end the photographing operation.
[0082]
As described above, according to the imaging apparatus according to the present embodiment, the diaphragm drive and the leading blade are not driven in a series in which the leading blade starts running after waiting for the diaphragm driving to be completed. Since the driving is overlapped, the aperture driving time during the release time lag can be increased. Accordingly, the number of steps that can be narrowed down while the release time lag is kept constant increases, and the depth of field increases, so it is possible to take a photograph that is focused on a fast-moving subject or the like.
[0083]
Also, since the leading blade finishes running almost at the same time as the release stabilization timer expires, the time for extra light to irradiate the CCD, which is the imaging means, can be shortened as much as possible to prevent the occurrence of problems such as smear. It becomes possible to do.
[0084]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.
[0085]
The configuration of the electronic still camera that is the imaging apparatus according to the present embodiment is the same as that of FIG. 1 of the first embodiment described above, and the electronic still camera that is the imaging apparatus according to the present embodiment. Since the table showing the relationship between the number of aperture stages in the camera and the aperture driving time according to the number of aperture stages is the same as that in FIG. 4, both figures will be used as necessary.
[0086]
FIG. 6 is a time chart showing the operation timing after the release start “after the second switch (SW2) 22b is turned on” in the electronic still camera which is the imaging apparatus according to the present embodiment.
[0087]
As already described in the first embodiment, when the second switch (SW2) 22b, which is a release operation, is turned on, the mirror-up operation starts and the operation of the mirror-up timer: T1 starts. To do. At the same time, the diaphragm 2 starts to be driven.
[0088]
Further, the diaphragm stage number of the diaphragm 2 that has already been determined is checked against the table of FIG. 4, the diaphragm driving time: T2 is set, and the operation of the T2 timer is started.
[0089]
Next, the MPU 20 compares T1 and T2, and selects whichever is longer. In the case of FIG. 4, since T2 is longer, T2 is selected.
[0090]
Next, the MPU 20 calculates a shutter start timer: T4 at (T2-T3).
[0091]
Here, T3 is the shutter drive time, and is determined by (lead blade time lag) + (curtain speed of the leading blade) as shown in FIG.
[0092]
The leading blade time lag is the actual opening of the main body opening portion (hereinafter referred to as aperture) after the leading blade of the mechanical shutter device 6 starts to be driven by the leading blade travel start signal from the shutter driving circuit 17. It is time to start doing. The curtain speed of the leading blade is the time for the leading blade to travel through the aperture.
[0093]
After the T4 time thus calculated has elapsed, the leading blade starts traveling by the leading blade traveling start signal from the shutter driving circuit 17, and the operation of the shutter driving time: T3 timer starts. Then, after the shutter drive time T3 has elapsed (the leading blade is completely open), the CCD drive circuit 18 drives the CCD 7 to start the charge accumulation operation (the electronic shutter operation starts).
[0094]
In this way, the travel start timing of the leading blade is controlled by the timer, and the travel operation is started (overlapped) while the diaphragm 2 is being driven. Therefore, the release time lag can be shortened as compared with the prior art by the amount of overlap.
[0095]
In addition, when the aperture driving time is open, the traveling operation of the leading blade is started with overlapping the mirror up, and in this case also, the release time lag can be shortened.
[0096]
Next, accumulation operation is performed for a predetermined time with the Tv value determined based on the exposure control value, and the rear blade of the mechanical shutter device 6 travels in accordance with the rear blade travel start signal from the shutter drive circuit 17 in accordance with the end timing. The operation is started, and the light receiving surface of the CCD 7 is set in a light shielding state.
[0097]
The CCD 7 transfers the signal charge accumulated in the photoelectric conversion element to the vertical transfer CCD at the end of the charge accumulation time, and performs normal reading as a signal charge reading operation at the timing of the trailing blade driving end. End the sequence.
[0098]
As described above, according to the imaging apparatus according to the present embodiment, the traveling of the front blade of the mechanical shutter means is completed substantially simultaneously with the completion of the mirror up. The release time lag can be shortened as compared with the case of starting the operation.
[0099]
In addition, since the time for irradiating light to the imaging means such as a CCD can be shortened as much as possible, problems such as smear can be prevented.
[0100]
(Other embodiments)
An object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above embodiments to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus. Needless to say, this can also be achieved by reading and executing the program code stored in the storage medium.
[0101]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
[0102]
Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. -RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM, etc. can be used.
[0103]
Further, by executing the program code read by the computer, not only the functions of the above embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code However, it is needless to say that a case where the function of each embodiment described above is realized by performing part or all of the actual processing is included.
[0104]
Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.
[0105]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to increase the number of stages that can be narrowed down in the release time lag while suppressing deterioration in image quality at the time of imaging using the electronic shutter means, and problems such as smear. It is possible to eliminate the effect.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an electronic still camera that is an imaging apparatus according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing a flow of shooting operation of the electronic still camera which is the image pickup apparatus according to the first embodiment of the present invention.
FIG. 3 is a flowchart showing a flow of shooting operation of the electronic still camera which is the image pickup apparatus according to the first embodiment of the present invention.
FIG. 4 is a diagram showing a table representing the relationship between the number of aperture stages and the aperture time in the electronic still camera which is the imaging apparatus according to the first embodiment of the present invention.
FIG. 5 is a time chart showing the timing of the shooting operation in the electronic still camera which is the imaging apparatus according to the first embodiment of the present invention.
FIG. 6 is a time chart showing the timing of a shooting operation in an electronic still camera that is an imaging apparatus according to a second embodiment of the present invention.
FIG. 7 is a time chart showing the timing of a shooting operation in an electronic still camera which is a conventional imaging device.
[Explanation of symbols]
1 Shooting lens unit
2 Aperture
3 Penta prism
4 Main mirror
5 Submirror
6 Mechanical shutter device
7 CCD
8 A / D converter
9 Video signal processing circuit
10 Compression circuit
11 Memory card
12 AF drive circuit
13 Aperture drive circuit
14 Mirror drive circuit
15 Focus detection circuit
17 Shutter drive circuit
18 CCD drive circuit
19 LCD monitor
20 Microcomputer (MPU)
21 Switch sense circuit
22 Photometric sensor
22a First switch (SW1)
22b Second switch (SW2)
23 Photometric circuit

Claims (4)

Imaging means for imaging subject light;
A diaphragm unit that starts a diaphragm operation in response to a release operation, and adjusts the amount of subject light incident on the imaging unit by completing the diaphragm operation when a set diaphragm operation time has elapsed ;
When a longer time has elapsed by comparing a release stabilization timer time that is set in advance as a time from when the release operation is performed to when the imaging operation by the imaging unit is started, and the aperture operation time, the imaging is performed. Electronic shutter means for supplying an imaging start signal to the means and starting an imaging operation;
A light-shielding unit that shields the light-receiving surface of the image-capturing unit, starts opening the light-shielding unit when a predetermined time has elapsed since the release operation is performed, and starts the imaging operation by the electronic shutter unit. Mechanical shutter means for driving the light shielding means so that the opening operation is completed,
An image pickup apparatus characterized in that an opening operation of the light shielding means is started before the diaphragm operation is completed . The release stabilization timer time T1, T 2 the diaphragm driving time, when the time required for the mechanical shutter unit is completed from the start of the opening operation of the front Symbol shading means has a T 3, the predetermined time , the imaging apparatus according to claim 1 Symbol mounting, characterized in that the T1 and the longer time of the T 2 is the time obtained by subtracting the T3. Storage means for storing a table that defines the correspondence between the number of aperture stages that can be set by the aperture means and the T2.
The imaging apparatus according to claim 2 , wherein T2 is determined according to the number of aperture stages set at the time of imaging according to the correspondence determined in the table . 3. The imaging apparatus according to claim 2, wherein the T2 is calculated by applying the aperture stage number set at the time of imaging to a relational expression indicating a relationship between the aperture stage number of the aperture means and the T2.

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