JP4863499B2 - Image recording apparatus and control method thereof - Google Patents

Description

The present invention relates to an image recording apparatus and a control method thereof, and more particularly to an image recording apparatus and a control method thereof capable of recording a moving image at a higher frame rate than usual.

  Generally, an imaging device such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor is used for a video camera. Recently, it has become possible to read images from these image sensors at a higher frame rate than usual, record them on a recording medium, and reproduce them as slow moving images with smooth motion.

  For example, n images are read out in one field period, recorded together in one field image, and displayed one by one in one field period when reproduced, thereby reproducing a 1 / n-times moving image. An imaging device has been proposed (see, for example, Patent Document 1).

  In addition, an imaging apparatus has been proposed that can read a moving image with a lower resolution and a higher frame rate than usual by shifting the exposure time of adjacent pixel groups without driving the imaging element at high speed (for example, , See Patent Document 2).

  A moving image having a higher frame rate than usual increases the amount of data with respect to the recording time, and therefore the recordable time with respect to the capacity of the recording medium is shortened. If the recordable time is kept long, the amount of data per frame must be reduced, and the quality of the recorded moving image is degraded. Therefore, there are cases where it is desired to record only a specific scene being shot as a moving image with a high frame rate.

Therefore, during recording of moving images, a recording device that records a moving image with a high frame rate in place of a moving image with a normal frame rate in response to a frame rate switching instruction has been proposed (for example, Patent Documents). 3).
Japanese Patent No. 3596307 JP 2004-032100 A JP 2006-325881 A

  However, in the techniques described in Patent Documents 1 to 3, when the frame rate at the time of reading an image signal from the image sensor during recording of a moving image is switched to a frame rate higher than normal, the shutter speed, aperture, gain Exposure parameters such as may change. For this reason, only the scene shot at a high frame rate may change the feeling of focus and noise, and the texture of the moving image may change. In addition, the recorded moving image may not be recorded with a desired exposure parameter.

An object of the present invention is to provide an image recording apparatus capable of recording a moving image without changing the texture even when the frame rate at the time of reading an image signal from an image sensor is switched, and a control method therefor. is there.

To achieve the above object, an image recording apparatus according to the present invention, a reading means for reading an image pickup means for generating an image signal, an image signal generated by the previous SL imaging means in accordance with the exposure amount, the reading and recording means for recording an image signal read as a moving image by means, the switching means for during the recording by the recording means switches the frame rate of the reading means, wherein said frame rate Ri by the switching means And an exposure control unit that does not change an exposure time of the imaging unit when the frame rate is changed .

In order to achieve the above object, an image recording apparatus control method according to the present invention includes an imaging unit that generates an image signal according to an exposure amount, a reading unit that reads out an image signal generated by the imaging unit, And a recording unit that records the image signal read by the reading unit as a moving image on a recording medium, wherein the frame rate of the reading unit is set during recording by the recording unit. A switching step of switching, and an exposure control step of not changing an exposure time of the imaging means in accordance with the change of the frame rate when the frame rate is switched in the switching step.

According to the present invention, even when switching the frame rate at the time of reading out an image signal from an imaging element, it is possible to record the moving image without changing the texture.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing an internal configuration of an image recording apparatus according to the first embodiment of the present invention.

  1, the video camera 100 includes a CPU 102, a RAM 103, a ROM 104, an operation unit 105, a camera control unit 111, a recorder control unit 121, an AFE (Analog Front End) 145, and a lens control unit 140. These are connected to each other via a bus 101.

  The video camera 100 also includes a RAM 114, a RAM 124, a CCD image sensor 142, a video signal output terminal 128, an LCD 126, and a DVD (Digital Versatile Disk) 125.

  The CPU 102 operates by a control program stored in the ROM 104, and uses the RAM 103 as a temporary information storage location during operation. Further, the CPU 102 receives the periodic interrupt signal from the camera control unit 111 and periodically refers to and sets each connected device, thereby controlling the entire video camera 100.

  The video camera 100 includes operation keys such as a mode dial, a shutter button, and a cross key (not shown). The state of these operation keys is held in the operation unit 105. The CPU 102 acquires the state of the operation key held in the operation unit 105, and performs settings for the AFE 145, the camera control unit 111, and the recorder control unit 121 based on the state of the operation key. As a result, the CPU 102 performs a shooting operation at a normal frame rate and a high-speed frame rate, which will be described later.

  The AFE 145 includes a timing generation (TG) circuit, a correlated double sampling (CDS) circuit, an automatic gain (AGC) circuit, and an analog / digital (A / D) conversion circuit (not shown). The TG circuit drives the CCD image sensor 142 by outputting various timing signals based on the synchronization signal output from the synchronization signal generation circuit provided in the camera control unit 111 according to the setting of the CPU 102.

  The CDS circuit samples the image signal output from the CCD image sensor 142 while removing noise generated between pixels when the image signal is read out. The AGC circuit amplifies the image signal by the gain setting of the CPU 102 and outputs it to the A / D conversion circuit when the output voltage of the image signal output from the CDS circuit is small due to insufficient exposure time. The A / D conversion circuit converts the image signal from an analog signal to a digital signal and outputs the converted signal to the camera control unit 111.

  The camera control unit 111 is an application specific IC (ASIC) including a synchronization signal generation circuit, an interrupt generation circuit, an image signal input circuit, an image signal level detection circuit, an image signal processing circuit, an image signal output circuit, and a memory control circuit. (Not shown).

  The synchronization signal generation circuit generates a vertical synchronization (VD) signal and a horizontal synchronization (HD) signal that are asserted at a period corresponding to the frame rate of the photographing operation. The interrupt generation circuit asserts an interrupt signal for the CPU 102 when the VD signal generated by the synchronization signal generation circuit is asserted. The image signal input circuit acquires a progressive scan image signal output from the A / D conversion circuit in synchronization with the timing signal output from the TG circuit.

  The image signal level detection circuit calculates an integral value of the signal level for a partial region of the image signal input from the image signal input circuit. The CPU 102 uses the integrated value calculated by the image signal level detection circuit as the image signal level for exposure feedback control.

  The image signal processing circuit performs various types of image signal processing such as color conversion and resolution conversion on the image signal input from the image signal input circuit according to settings from the CPU 102. The image signal output circuit outputs an image signal obtained as an image signal processing result of the image signal processing circuit to the recorder control unit 121 by interlace scanning. For example, when the frame rate of the image signal input from the image signal input circuit is a normal 60 frames / second, the image signal output from the image signal output circuit is 60 fields / second, so the frame rate is half, 30 Frame / second. The memory control circuit controls reading and writing of data with respect to the RAM 114 as a temporary image signal storage location of the image signal input circuit, the image processing circuit, and the image signal output circuit.

  The recorder control unit 121 is an ASIC that includes an image signal input circuit, an image encoding circuit, an image decoding circuit, a DVD control circuit, an image signal output circuit, a liquid crystal display (LCD) control circuit, and a memory control circuit (not shown). (Illustrated).

  The image signal input circuit acquires the image signal output by the image signal output circuit included in the camera control unit 111. The image encoding circuit performs an encoding process in the MPEG (Motion Picture Experts Group) 2 format on the image signal input from the image signal input circuit during an image recording operation on the DVD 125.

  The DVD control circuit records code data obtained as a result of the encoding process of the image encoding circuit on the DVD 125, which is a recording medium, in accordance with the DVD logical format. Further, the DVD control circuit reproduces the code data recorded on the DVD 125 in accordance with the DVD logical format at the time of image reproduction operation from the DVD.

  The image decoding circuit performs 30 frames / second (60 fields / second) with respect to the code data output from the DVD control circuit during the image reproduction operation from the DVD regardless of the frame rate of the image signal input at the time of recording. The decoding process is performed in the MPEG2 format. For this reason, when an image signal shot at a high-speed frame rate higher than usual and recorded on the DVD 125 is reproduced, an image signal with smooth slow reproduction is obtained.

  The image signal output circuit converts the image signal input from the image signal input circuit to 30 frames / second (60 fields / second) regardless of the frame rate of the input image signal except during the image reproduction operation from the DVD 125. ) To the video signal output terminal 128. Further, during an image reproduction operation from the DVD 125, the image signal output from the image decoding circuit is output to the video signal output terminal 128 as it is at a normal frame rate. The LCD control circuit outputs the image signal output from the image signal output circuit to the LCD 126. The memory control circuit controls reading and writing of data with respect to the RAM 124 as a temporary image signal storage location of the image signal input circuit, the image encoding circuit, the image decoding circuit, and the DVD control circuit.

  FIG. 2 is a block diagram showing the configuration of the optical system of the video camera 100 of FIG.

  In FIG. 2, the subject image incident from the lens 150 is exposed on the exposure surface of the CCD image sensor 142. A diaphragm 151 is provided between the CCD image sensor 142 and the lens 150. The CPU 102 adjusts the amount of light reaching the exposure surface of the CCD image sensor 142 by controlling the aperture value of the aperture 151 according to the setting for the lens control unit 140, and performs exposure control.

  FIG. 3 is a diagram schematically showing a circuit configuration of the CCD image sensor 142 in FIG.

  In FIG. 3, a CCD image sensor 142 is a progressive scan type image sensor. The CCD image sensor 142 includes a photodiode 301, a vertical transfer circuit 302, and a horizontal transfer circuit 303 on an exposure surface, and a charge detection (FD) circuit 304 in an output unit. The vertical transfer circuit 302 and the horizontal transfer circuit 303 are composed of a CCD.

  These circuits are driven by a charge read (SG) signal, a charge sweep (SUB) signal, a vertical transfer timing signal, a horizontal transfer timing signal, and a charge reset signal received from the TG circuit included in the AFE 143.

  The photodiodes 301 are arranged in a matrix form as pixels, and accumulate charges according to the exposure time. The accumulated charge is transferred to the vertical transfer circuit 302 arranged in parallel in the vertical direction by the SG signal. Further, the accumulated electric charge is swept out on the substrate by the SUB signal. Furthermore, the charge exceeding the saturation charge amount of the photodiode 301 is released onto the substrate.

  The vertical transfer circuit 302 serially transfers the signal charge received from the photodiode 301 in the vertical direction toward the horizontal transfer circuit 303 by a vertical transfer timing signal. The horizontal transfer circuit 303 receives the signal charges transferred from the plurality of vertical transfer circuits 302 in parallel, and serially transfers the signal charges to the FD circuit 304 in the horizontal direction by a horizontal transfer timing signal. The FD circuit 304 discharges the remaining charge to the outside by the charge reset signal, receives the transferred charge, and outputs a potential difference proportional to the charge amount as an image signal.

  Here, the CCD image sensor 142 reads out an image signal at a normal frame rate of 30 frames / second, but can also read out an image signal at a high frame rate of 90 frames / second, which is 3 × speed. When the frame rate is tripled, the CPU 102 triples the frequency of the VD signal and HD signal output from the synchronization signal generation circuit by setting the camera signal processing unit 111. At the same time, the CPU 102 also triples the frequency of various timing signals output from the timing signal generation circuit by setting the AFE 143. As a result, the charges accumulated in the photodiode 301 are transferred vertically and horizontally at a speed three times as high, and an image signal can be read out from the FD circuit 304 at a speed three times higher than normal.

  FIG. 4 is a timing chart of an electronic shutter operation for controlling the exposure time of the CCD image sensor 142 of FIG.

  FIG. 4 shows the timing of the VD signal, the HD signal, the charge amount Q accumulated in one photodiode 301, the SG signal, and the SUB signal.

  For readout of the image signal, the synchronization signal generation circuit of the camera signal processing unit 111 asserts the HD signal for each horizontal scan (1H) and the VD signal for each vertical scan (1V). Assert.

  The timing signal output circuit included in the AFE 143 asserts the SUB signal 402 at an arbitrary timing in 1H increments. As a result, the charge 404 accumulated in the photodiode 301 after the SG signal 401 of 1 V before being asserted is swept out. By this sweeping-out operation, the charge 405 can be accumulated in the photodiode 301 in a desired exposure time S up to 1 V in 1H increments until the SG signal 403 is asserted with a constant phase difference with respect to the VD signal.

  As described above, the electronic shutter operation is realized by adjusting the exposure time, that is, the shutter speed by controlling the position where the SUB signal is asserted. Note that the maximum value of the exposure time is the frame interval or field interval of the frame rate. For example, when an image signal is read from the CCD image sensor 142 at a normal frame rate of 60 frames / second, the shutter speed is 1/60 seconds at the longest. When the image signal is read from the CCD image sensor 142 at a high frame rate of 180 frames / second, the shutter speed is a maximum of 1/180 seconds.

  In this embodiment, a progressive scan type CCD image sensor is used, but other image sensors such as an interface scan type image sensor and a CMOS image sensor may be used.

  Next, exposure control of the video camera 100 will be described.

  The CPU 102 performs exposure control by feedback controlling the shutter speed of the CCD image sensor 142, the aperture value of the aperture 151, and the gain setting of the AFE 143 based on the image signal level acquired from the camera control unit 111.

  FIG. 5 is a program diagram used for exposure control in the shooting operation at the normal frame rate of the video camera 100 of FIG.

  In FIG. 5, the horizontal axis indicates the shutter speed S of the CCD image sensor 142, and the vertical axis indicates the aperture value F of the aperture 151.

For example, when shooting at S = 1/500 and F = 9.0, when the image signal level is lower than a specified value, S = 1/90, F = Adjust S and F in the direction of 1.8. Conversely, when the image signal level becomes higher than the specified value, S and F are adjusted in the direction of S = 1/1400 and F = 25.6 in order to reduce the exposure amount.
When the exposure amount is further increased from S = 1/90 and F = 1.8, only S is adjusted in the direction of S = 1/60. If the image signal level is lower than the specified value even in the state of S = 1/60, the image signal level is adjusted by the gain setting of the AFE 143. This adjustment is performed with a higher resolution than the scale in the figure.

  FIG. 6 is a program diagram used for exposure control in the shooting operation at a high frame rate of the video camera 100 of FIG.

  In FIG. 6, the horizontal axis indicates the shutter speed S of the CCD image sensor 142, and the vertical axis indicates the aperture value F of the aperture 151.

  For example, when photographing is performed at S = 1/500 and F = 9.0, when the image signal level becomes lower than a specified value, S = 1/180, F = Adjust S and F in the direction of 1.8. Conversely, when the image signal level becomes higher than the specified value, S and F are adjusted in the direction of S = 1/1400 and F = 25.6 in order to reduce the exposure amount.

  When the exposure amount is further increased from S = 1/180 and F = 1.8, only F is adjusted in the direction of F = 1.8. If the image signal level is lower than the specified value even in the state of F = 1.8, the image signal level is adjusted by the gain setting of the AFE 143. This adjustment is performed with a higher resolution than the scale in the figure.

  Next, two shooting modes provided in the video camera 100 will be described.

  The video camera 100 can switch between a normal mode (first shooting mode) in which shooting is performed only at a normal frame rate and an S mode (second shooting mode) in which shooting at a normal frame rate and a high-speed frame rate of 3 × speed can be switched. With. When the user selects one of the two shooting modes using the operation unit 105 in a standby state where recording on the DVD 125 is not performed, the CPU 102 acquires the shooting mode selected by the operation unit 105.

  When the normal mode is selected by the operation unit 105, the CPU 102 uses the normal frame rate program diagram (FIG. 5) for the subsequent exposure control. Further, when the S mode is selected by the operation unit 105, the CPU 102 uses a program diagram (FIG. 6) for a high-speed frame rate for subsequent exposure control.

  Next, the frame rate switching operation during shooting in the video camera 100 will be described.

  The video camera 100 includes an S button (not shown). The CPU 102 acquires the state of the S button from the operation unit 105, and executes the frame rate switching process shown in FIG.

  FIG. 7 is a flowchart of the frame rate switching process executed by the CPU 102 in FIG.

  In FIG. 7, first, the CPU 102 acquires the state of the S button from the operation unit 105, and determines whether or not the S button is pressed by the user (step S701).

  If it is determined in step S701 that the S button has been pressed by the user, it is determined whether or not the current shooting mode is the S mode (step S705).

  As a result of the determination in step S705, when the shooting mode is not the S mode, that is, when the shooting mode is the normal mode, this process is terminated. On the other hand, when the shooting mode is S mode, it is determined whether or not shooting is being performed at a high frame rate (step S706).

  If the result of determination in step S705 is that shooting is in progress at a high frame rate, this processing ends. On the other hand, if the result of determination in step S705 is that shooting is not being performed at the high frame rate, that is, shooting is being performed at the normal frame rate, the process shifts to shooting at the high frame rate (step S707).

  On the other hand, if the result of determination in step S701 is that the user has not pressed the S button, it is determined whether or not shooting is being performed at the normal frame rate (step S702).

  If the result of determination in step S702 is that shooting is being performed at the normal frame rate, this processing ends. On the other hand, if the result of determination in step S702 is that shooting is not being performed at the normal frame rate, that is, shooting is being performed at a high frame rate, it is determined whether or not it is possible to shift to shooting at the normal frame rate (step S702). S703).

  If the result of determination in step S703 is that it is not possible to shift to shooting at the normal frame rate, this processing ends. On the other hand, if the result of determination in step S703 is that transition to shooting at the normal frame rate is possible, processing shifts to shooting at the normal frame rate (step S704).

  Here, in step S703, the condition that allows the shift to the shooting at the normal frame rate is that the total number of frames of the images shot after shifting to the shooting at the high frame rate is the high speed frame rate / normal frame rate. Is a multiple of. For example, when the high-speed frame rate is 180 frames / second and the normal frame rate is 60 frames / second, the total number of frames is a multiple of three.

  This is because the image signal output circuit included in the recorder control unit 121 at the time of shooting operation outputs the image signal to the video signal output terminal 128 at 30 frames / second (60 fields / second) regardless of the frame rate of the input image signal. This is because it outputs to. By satisfying the above conditions, the image signal input to the image signal output unit included in the recorder control unit 121 and the phase of the output image signal match when shifting to the normal frame rate. It is possible to return to the normal state before performing.

  According to the present embodiment, the video camera 100 has two shooting modes, and performs exposure control using different program diagrams according to the shooting modes. Thereby, even when the frame rate at the time of reading an image signal from the image sensor is switched, a moving image can be recorded without changing the texture. Also, the frame rate can be switched regardless of the shooting conditions.

  In the present embodiment, it is possible to switch between two frame rates, a normal frame rate and a high-speed frame rate. However, the present invention is not limited to this, and switching to three or more frame rates is possible. May be.

  Next, a second embodiment of the present invention will be described.

  The internal configuration of the video camera as the image recording apparatus according to the present embodiment is the same as that shown in FIG.

  In the first embodiment, the video camera 100 has two shooting modes, and exposure control is performed using different program diagrams according to the shooting modes. On the other hand, in the second embodiment, the video camera 100 includes one shooting mode for determining whether or not to accept an instruction to switch the frame rate by the operation unit 105 according to the shutter speed during the shooting operation.

  In the present embodiment, it is used that the program diagrams for exposure control (FIGS. 5 and 6) in the shooting operation at the normal frame rate and the high frame rate are the same in the range of S ≦ 1/180. That is, the CPU 102 accepts a frame rate switching instruction from the operation unit 105 only under the condition of S ≦ 1/180, and switches the program diagram to be used in accordance with the frame rate switching.

  For example, when shooting is performed at the normal frame rate under the conditions of S = 1/500 and F = 9.0, it is possible to continue shooting under the same conditions even when the frame rate is switched to the high speed frame rate. Therefore, in this case, the CPU 102 receives an instruction to switch the frame rate by the operation unit 105.

  On the other hand, when shooting is performed at the normal frame rate under the conditions of S = 1/120 and F = 2.2, shooting at the same condition is impossible at the high frame rate. Therefore, in this case, the CPU 102 does not accept a frame rate switching instruction from the operation unit 105.

  Note that if the image signal level becomes lower than the specified value during the shooting operation at the high frame rate, it may be adjusted to the range of F <3.2 by exposure control according to the program diagram (FIG. 6). is there. For example, during shooting under the conditions of S = 1/180 and F = 1.8, after shifting to the normal frame rate program diagram (FIG. 5), the conditions are set to S = 1/120 and F = 2.2. May be adjusted. In this case, when the normal frame rate is shifted again, the image quality of the moving image being recorded changes even if no change has occurred in the shooting target. Therefore, the CPU 102 does not switch the program diagram in the range of F <3.2 even when the frame rate is switched, and then the program diagram is adjusted when the adjustment is performed in the range of F ≧ 3.2. Switch.

  FIG. 8 is a diagram showing a display screen when an instruction to switch to the high-speed frame rate of the LCD 126 in FIG. 1 is received.

  In FIG. 8, when the shooting operation is being performed under the condition of S ≦ 1/180 at the normal frame rate, the CPU 102 receives an instruction to switch to the high-speed frame rate. Therefore, an icon 801 indicating that switching to a high frame rate is possible is displayed on the LCD 126 to notify the user that shooting at a high frame rate is possible.

  FIG. 9 is a diagram showing a display screen when an instruction to switch to the high-speed frame rate of the LCD 126 in FIG. 1 is not accepted.

  In FIG. 9, when the shooting operation is being performed under the condition of S> 1/180 at the normal frame rate, the CPU 102 does not accept an instruction to switch to the high-speed frame rate. Therefore, an icon 901 indicating that switching to the high frame rate cannot be performed is displayed on the LCD 126 to notify the user that shooting at the high frame rate is impossible.

  According to the present embodiment, the video camera 100 determines whether or not to accept an instruction to switch the frame rate by the operation unit 105 according to the shutter speed during the shooting operation. Thereby, even when the frame rate at the time of reading an image signal from the image sensor is switched, a moving image can be recorded without changing the texture. Further, exposure control according to the frame rate can be performed.

  In the present embodiment, it is possible to switch between two frame rates, a normal frame rate and a high-speed frame rate. However, the present invention is not limited to this, and switching to three or more frame rates is possible. May be.

  Any of the processes, functions, and the like described in the above embodiments can be realized by a computer-readable program or the like.

  In this case, the processes, functions, and the like described in the above embodiments are realized when a computer (CPU, MPU, or the like) included in the system or apparatus executes the above programs. In other words, the above-described program or the like causes the computer included in the system or apparatus to execute the processes and functions described in the above-described embodiment. In this case, the above-described program or the like is provided to a computer included in the system or apparatus via a computer-readable storage medium or a network.

  A magnetic disk, an optical disk, a magneto-optical disk, a hard disk, a magnetic tape, a nonvolatile memory, or the like can be used as a storage medium that provides the above-described program or the like to a computer included in the system or apparatus.

  Moreover, you may comprise a part of said program etc. using OS (operating system) etc. which are operate | moving on the computer.

  Furthermore, a part of the above-described program may be executed by a function expansion board inserted into the computer or a function expansion unit connected to the computer.

1 is a block diagram showing an internal configuration of an image recording apparatus according to a first embodiment of the present invention. It is a block diagram which shows the structure of the optical system of the video camera 100 of FIG. FIG. 3 is a diagram schematically showing a circuit configuration of a CCD image sensor 142 in FIG. 2. 4 is a timing chart of an electronic shutter operation for controlling the exposure time of the CCD image sensor 142 of FIG. 3. FIG. 2 is a program diagram used for exposure control in a shooting operation at a normal frame rate of the video camera 100 of FIG. 1. FIG. 2 is a program diagram used for exposure control in a shooting operation at a high frame rate of the video camera 100 of FIG. 1. It is a flowchart of the frame rate switching process performed by CPU102 in FIG. FIG. 2 is a diagram showing a display screen when an instruction to switch to a high-speed frame rate of the LCD 126 in FIG. 1 is accepted. FIG. 2 is a diagram showing a display screen when an instruction to switch to a high frame rate of the LCD 126 in FIG. 1 is not accepted.

Explanation of symbols

100 video camera 102 CPU
105 Operation Unit 111 Camera Control Unit 121 Recorder Control Unit 140 Lens Control Unit 142 CCD Image Sensor

Claims (7)

Imaging means for generating an image signal according to the exposure amount ;
Reading means for reading an image signal generated by the pre-Symbol image pickup means,
Recording means for recording the image signal read by the reading means as a moving image on a recording medium;
Switching means for switching the frame rate of the reading means during recording by the recording means ;
If the frame rate Ri by the said switching means is switched, the image recording apparatus characterized by comprising a, and exposure control means does not change the exposure time of the imaging means according to a change of the frame rate. The switching unit is capable of switching the frame rate of the reading unit between a first frame rate and a second frame rate faster than the first frame rate during recording by the recording unit,
When the signal level of the image signal is lower than a predetermined value in a state where the exposure time of the imaging means is the first exposure time, the exposure control means sets the frame rate of the reading means to the first frame rate. In this case, exposure control is performed by setting the exposure time of the image pickup means to an exposure time longer than the first exposure time, and when the frame rate of the reading means is the second frame rate, the exposure time of the image pickup means The image pickup apparatus according to claim 1, wherein exposure control is performed with the first exposure time as the first exposure time. When the frame rate is switched from the second frame rate to the first frame rate by the switching unit, the exposure control unit has an exposure time of the imaging unit at the second frame rate. 3. The image recording according to claim 2, wherein the exposure time of the imaging unit is not changed in accordance with the change of the frame rate even when the exposure time is different from an appropriate exposure time corresponding to the first frame rate. apparatus. When the frame rate is switched from the second frame rate to the first frame rate by the switching unit, the exposure control unit also changes an exposure control value other than the exposure time with the change of the frame rate. The image recording apparatus according to claim 3, wherein the image recording apparatus is not. The exposure control means, after the frame rate is switched from the second frame rate to the first frame rate by the switching means, until exposure control corresponding to a change in the signal level of the image signal is performed. The image recording apparatus according to claim 3, wherein an exposure time of the imaging unit at the second frame rate is maintained. The switching means does not switch the frame rate from the first frame rate to the second frame rate when the set exposure time is an exposure time longer than the first exposure time. The image recording apparatus according to any one of claims 2 to 5. Imaging means for generating an image signal according to the exposure amount, reading means for reading the image signal generated by the imaging means, and recording means for recording the image signal read by the reading means as a moving image on a recording medium A method of controlling an image recording apparatus comprising:
A switching step of switching the frame rate of the reading means during recording by the recording means;
An image recording apparatus control method comprising: an exposure control step that does not change an exposure time of the image pickup means when the frame rate is switched in the switching step.

Images