JP2000244821A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image pickup device to suppress generation of a pseudo signal caused by the changes of space sampling characteristics due to special driving of an imaging device. SOLUTION: This image pickup device is constituted by providing a lens 12, a diaphragm and a shutter mechanism 13, a low-pass filter block 14 consisting of a first standard low-pass filter 14-1, a dummy glass for correcting the length of an optical path and a second low-pass filter 14-2 to be selectively used, a single CCD color imaging device 11 with an electronic shutter function, a CCD driver 29 to drive the CCD imaging device in various read drive modes under the control of a CPU 19 and a filter changer 30 to drive the dummy glass constituting the low-pass filter block and the second low-pass filter by exchanging them according to the read drive mode set in the CCD driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging apparatus capable of effectively suppressing a pseudo signal based on a change in spatial sampling characteristics accompanying a special driving readout of a charge transfer type imaging element capable of color imaging.

[0002]

2. Description of the Related Art In recent years, an electronic imaging device capable of inputting image data to a multimedia device, a so-called electronic still camera, has been developed. An electronic still camera generally acquires an image using a solid-state imaging device such as a CCD imaging device, displays the acquired image on a viewfinder such as a liquid crystal panel, and records the image on a recording medium in response to a user pressing down a trigger. To be recorded. This electronic still camera is required to have higher image quality and improved operability. To meet this demand, a still image to be photographed and recorded while using a CCD image sensor with a large number of pixels has been used. It is essential that a moving image with the same angle of view can be confirmed in real time by a viewfinder.

When a high-resolution CCD image pickup device is used, a high-quality still image can be obtained, but the image reading speed of one screen becomes slow, so that an image recognized as a moving image cannot be displayed on a viewfinder. .

For this reason, conventionally, for example, Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent No. 6244, line addition reading for adding the electric charges of the pixels arranged in each horizontal direction in the vertical direction, or thinning reading for reading out by thinning out the pixels arranged in the vertical direction is performed. Although the image quality deteriorates, the image reading of one screen is performed at a high speed so that the moving image can be displayed.

[0005] However, the conventional line addition or thinning-out reading system disclosed in the above publication corresponds to the non-interlace system.
The above-mentioned publication does not disclose any specific technology for making such a high-speed readout method compatible with the interlace method.

When an interlace system is applied to a general interline type CCD image pickup device, for example, FIG.
The configuration shown in FIG. This configuration example is 4
The phase drive type is two pixels, which is a minimum repeating unit, but for convenience of explanation, 16 pixels are shown as one set, and are repeatedly arranged in the vertical direction along each vertical transfer path. In FIG. 6, each pixel 1 is indicated by putting numbers from 1 to 16 in squares. Each set of pixels has two vertical transfer electrodes 1a, 1a of a group and b group of the vertical transfer path 2.
2a, 2b;... 16a, 16b are arranged in correspondence with each other, and each pixel 1 is connected to a transfer electrode 1a, 2a,
... Are connected to the transfer channels of the vertical transfer path 2 corresponding to 16a. And each electrode of the vertical transfer path 2
The four-phase shift pulse is sequentially applied to a set of four transfer electrodes. The four-phase shift pulse is sequentially applied to a set of four transfer electrodes. The charges transferred to the transfer path 2 are transferred in one direction. In addition,
In FIG. 6, reference numeral 5 denotes a shift pulse input terminal.

Here, among the transfer electrodes of the vertical transfer path 2,
The transfer electrodes 1b, 2b,..., 16b of the b group are electrodes that simply contribute to the charge transfer, while the transfer electrodes 1a, 2a,. In addition, they are commonly used so as to function as a gate pulse application electrode for opening the transfer gate 3. Therefore, when a normal shift pulse is applied, the charge transfer operation is performed. However, the voltage is selected by selectively applying a voltage equal to or higher than a predetermined value at a predetermined timing to the transfer electrodes of the predetermined a group. The transfer gate 3 corresponding to the predetermined transfer electrode is opened, and the pixel charge is transferred to the vertical transfer path 2.

In the case of four-phase driving, four transfer channels, for example, four transfer channels of a vertical transfer path corresponding to the transfer electrodes 1a, 1b, 2a, 2b become one unit, and one pixel corresponds to one pixel. Since only electric charges can enter, the number of pixels transferred by the vertical transfer path 2 is half of the number of pixels originally arranged in the vertical direction. Become.

When a special driving system such as high-speed (double speed) reading is applied to the interlaced CCD imaging device, a configuration as shown in FIG. 7 can be considered. In this configuration example, among the transfer paths of the vertical transfer path 2, transfer electrodes 1b, 2b,.
... 16b is an electrode completely related only to charge transfer, so the four-phase driven interlaced CCD shown in FIG.
As in the case of the image pickup device, the same is used for every four transfer electrodes. On the other hand, the transfer electrodes 1a, 2a,
... 16a must also function as a transfer gate electrode in order to perform special driving such as high-speed reading, so that gate pulses can be applied independently. Therefore, the transfer electrodes 1a, 2a,.
.., 16a need to be provided with an extraction electrode for applying a gate pulse independently. However, even in this case, when a repetitive structure in units of 16 pixels is adopted, the total number of extraction electrodes is 16 (4a), which are the number of extraction electrodes 4A that independently apply a gate pulse to the transfer electrode (a Since two extraction electrodes are originally provided, the number of newly added electrodes is 14), and the total number of the extraction electrodes 4B for the transfer electrodes in the group b is 18, which is 18 in total. In FIG. 7, reference numeral 6 denotes an input terminal of the independent gate pulse application extraction electrode 4A.

Then, each transfer electrode 1a, 1b; 2a, 2
b,... 16b, 16b, so that the transfer pulse application order similar to that shown in FIG. 6 is applied to transfer electrodes 1b, 2b,. With respect to a plurality of transfer / transfer pulse applying lead electrodes 4A selected from the plurality of transfer / pulse applying lead electrodes 4B and independent transfer / transfer pulse applying lead electrodes 4A, 4
By applying a phase shift pulse, four-phase driving can be performed similarly to the CCD image pickup device shown in FIG. At the same time, a special driving such as a desired high-speed (double speed) reading can be performed by appropriately selectively applying and supplying a gate pulse to each independent transfer / transfer pulse application extraction electrode 4A.

Next, a specific example of reading out a CCD image pickup device having a vertical transfer path having independent transfer / transfer pulse application extraction electrodes for each transfer electrode will be described with reference to FIG. . In FIG. 8, the numbers shown in the leftmost column indicate the order of one set of pixel groups in a repeating configuration of 16 pixels in the vertical direction, and the display of read pixels or non-read pixels in each read mode is represented by a Bayer array. 2 pixels of the color filter in the horizontal direction are cut out and displayed. Pixels read out in a set of 16 pixels are indicated by hatching.

The imaging apparatus according to the present embodiment performs a conventional interlaced readout when a normal high-quality still image is captured, and a detailed description thereof will be omitted. Since pixel information is read out completely independently, high resolution can be obtained. On the other hand, in order to obtain an image signal of the same accumulation time (exposure amount) in the two fields of Odd and Even, in addition to the electronic shutter, a mechanical type is used. It is assumed that a shutter is used together. In the following, each read mode for performing special driving, which is different from the all-pixel read mode that is the normal interlace read, will be described in detail.

First, a double speed addition mode will be described as a read mode. In this read mode, all pixels are read in two fields to form an image of one screen. Pixels read in the first field are hatched in the Odd column of read timing to the vertical transfer path (VCCD). The pixels read in the second field are indicated by hatching in the column of Even. This read-out method is the same as the conventional interlace-type read-out, and only charges the read-out pixels by 2 at the time of transfer from the vertical transfer path to the horizontal transfer path.
The only difference is that addition is performed for each pixel and reading is performed at double speed. Therefore, in this case, Odd and Eve
In order to obtain image signals of the same accumulation time (exposure amount) in the two fields of n, a mechanical shutter (optical shutter) is used in addition to the electronic shutter.

Next, reading in the double speed non-addition mode will be described. When a mechanical shutter is used together, it takes time to charge the shutter for the next shutter operation, and continuous operation cannot be performed from the viewpoint of durability. In the double speed non-addition mode, pseudo non-interlaced reading can be performed without using a mechanical shutter.
As the readout timing to D), two readouts of the first readout (displayed as 1st) and the second readout (displayed as 2nd) are performed for the image signal of one field by the charge accumulation time of both readout pixels. The image signal of one screen is obtained by performing the processing at short time intervals so as to hardly affect the image signal.

That is, at the first timing, G, B
The pixel signals of the second and fourth pixels and the pixel signals of the tenth and twelfth pixels are read out to extract the signals, and the R and G signals are extracted at the second timing. And the pixel signal of the seventh pixel and the pixel signal of the thirteenth and fifteenth pixels are read.

By the way, in the case of performing such reading, for example, the fourth pixel read at the first timing and the fifth pixel read at the second timing are adjacent to each other, so that reading at the first and second timings is performed. Simply setting to read out at short time intervals causes readout pixel charges at the 1st and 2nd timings to be mixed in the vertical transfer path, and cannot be transferred individually.
Therefore, as shown in the timing chart of FIG.
At the timing t ₁ of the TG1st gate pulse signal,
After the charges of the second, fourth, tenth, and twelfth pixels are transferred to the vertical transfer path via the transfer gate and read out, the vertical transfer path (VC
CD), one shift pulse is applied to perform vertical transfer for one step. Thereafter, at the second timing t ₂ , TG
With the second gate pulse signal, the charge of the fifth, seventh, thirteenth, and fifteenth pixels is read out to the vertical transfer path via the transfer gate.

As described above, by performing one-step vertical transfer between reading at the 1st and 2nd timings,
Since the charges of the fourth and fifth pixels are to be read with a one-step transfer channel between them, and are not read to the adjacent transfer channel,
There is no possibility that read charges are mixed.

In the following, data is sequentially transferred on the vertical transfer path, and when data is transferred from the vertical transfer path to the horizontal transfer path, operation is added, but reading at the 1st and 2nd timings is thinned out every other time. Since the pixel signal is read in the state, the vertical transfer is performed twice in each horizontal blanking period, and the pixel signal of one of the two pixels in the vertical direction is read out in a non-addition state as a signal charge. That is, reading in the double speed non-addition mode is obtained.

Next, the quadruple speed read mode, that is, 1
A mode in which four steps of vertical transfer are performed in the vertical transfer path during the horizontal blanking period and four pixels are added (four lines are added) will be described. First 4/16 at 4x speed
The mode is a mode in which charges of four pixels out of 16 pixels are read out, and four steps of vertical transfer are performed in one horizontal blanking period, four pixels are added, and the read signal charges of one pixel are read out. 6th at 1st timing
The signal of the 14th pixel is changed to the 1st and 9th at the 2nd timing.
Read out the signal of the pixel of the number. At this time, as in the case of the double speed non-addition mode, one-step vertical transfer is performed between reading at the 1st and 2nd timings. 1st and 2
After reading at the timing of nd, four steps of vertical transfer are performed on the horizontal transfer path every horizontal blanking period to add four pixels, and a pixel signal for one pixel is transferred to the horizontal transfer path. . As a result, reading in the 4 × speed 4/16 mode is performed.

Next, the 8/16 mode at 4 × speed will be described. In this mode, charges of eight pixels out of sixteen pixels are read out. In one horizontal blanking period, four steps of vertical transfer are performed, four pixels are added, and the read two pixels are read.
The signal charges for the pixels are read out. The signals of the second and fourth pixels and the signals of the tenth and twelfth pixels are read at the first timing, and the signals of the fifth and seventh pixels are read at the second timing. In addition, the signals of the thirteenth and fifteenth pixels are read. Also in this case, one-step vertical transfer is performed between reading at the first and second timings. 1
After reading at st and 2nd timing, 1
For each horizontal blanking period, four steps of vertical transfer are performed on the horizontal transfer path to add four pixels, and the pixel signals for two pixels are transferred to the horizontal transfer path. This makes 4x speed 8 /
Reading in 16 modes is performed.

As can be seen from the arrangement of readout pixels in the 16-pixel repetition configuration shown in FIG. 8, the 4 × speed 4/16 and 8/16 modes are used together with the all pixel 2 × speed addition mode and the 2 × speed non-addition mode. , 8 pixels can be read out even with a pixel array having a repetitive configuration, so that the 4 ×, 4/16, 8 /
The 16 modes can also be expressed as quadruple speed 2/8 and 4/8 modes.

[0022]

By the way, in a CCD image sensor, moiré occurs because pixels are discretely arranged. In a single-plate color CCD image sensor such as a Bayer array, a false color is generated. Is generated, an optical low-pass filter is used to suppress the occurrence. However, when the special drive reading is performed as described above, for example, the double speed non-addition mode or the 4
In reading in the double-speed addition mode, the spatial sampling frequency may be extremely reduced. That is, in the case of performing the special driving readout, information is thinned out in some manner, so that it becomes equivalent to an image pickup device having few pixels, and it becomes necessary to use a low-pass filter having different characteristics.

A prior art relating to switching of an optical low-pass filter in an image pickup apparatus is disclosed in JP-A-8-29.
No. 8667 discloses an image pickup apparatus having a color photographing mode as a standard photographing mode and a high-resolution photographing mode for performing monochrome photographing ignoring a color filter in contrast to the standard photographing mode. There is disclosed a device in which a dynamic low-pass filter is switched.

However, the technique disclosed in the above publication is a technique for simply switching an optical low-pass filter in response to switching of a photographing mode having a different resolution. No consideration is given to a method of suppressing the generation of a pseudo signal accompanying the above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in an imaging apparatus capable of special driving including high-speed reading, and is capable of generating a pseudo signal accompanying a change in spatial sampling characteristics due to special driving of an imaging element. It is an object of the present invention to provide an imaging device capable of effectively suppressing.

[0026]

According to a first aspect of the present invention, there is provided an imaging optical system, an imaging characteristic switching unit for switching a spatial frequency characteristic of the imaging optical system, and the imaging optical system. A charge transfer type image sensor for photoelectrically converting an output image of the system, a drive unit capable of driving the charge transfer unit of the image sensor in a plurality of selectable drive modes, and driving at least the drive unit in a predetermined drive mode Read-out control means for reading out an image signal from the image pickup device, wherein the image forming characteristic switching means constitutes an image pickup apparatus so as to switch a spatial frequency characteristic of the image pickup optical system according to the drive mode. Things.

The imaging apparatus having the above-mentioned configuration includes an imaging characteristic switching means for switching the spatial frequency characteristic of the imaging optical system, and the means switches the spatial frequency characteristic of the imaging optical system according to the drive mode. With this configuration, it is possible to effectively suppress a pseudo signal generated due to a change in the spatial sampling characteristic due to the driving mode of the image sensor.

[0028]

Next, an embodiment will be described. FIG. 1 shows a CC according to an embodiment of the imaging apparatus of the present invention.
FIG. 2 is a block diagram showing the overall configuration of an electronic camera using a D imaging device. In FIG. 1, reference numeral 11 denotes a single-chip color CCD image sensor for photoelectrically converting an optical signal into an electrical signal, which has an electronic shutter function. The CCD image sensor 11 includes a lens 12, an aperture and a shutter (optical Shutter) mechanism
The subject light is input through a low-pass filter (LPF) block 13 and a low-pass filter (LPF) block 14. The low-pass filter block 14 is a standard first low-pass filter.
14-1 and a dummy glass for optical path length correction and a second low-pass filter 14-2 selectively used. The dummy glass has the same thickness and the same refractive index as the second low-pass filter. And keeps the imaging (aberration) characteristics of the lens 12 unchanged. CCD image sensor
The output of 11 is amplified after noise is removed by a pre-processing circuit 15 including a correlated double sampling circuit and a preamplifier. 16 is a pre-processing circuit that is analog data
An A / D converter that converts 15 outputs to digital data.
A camera signal processing circuit 17 processes a signal from the CCD image sensor 11 as video data. 18 uses an imaging signal or the like from the CCD imaging device 11 prior to the original shooting,
AF detection circuit that extracts AF information to control focus, AE that extracts AE information to control exposure
AWB for setting detection circuit and white balance
This is an AWB detection circuit that extracts information.
The output signals from the E and AWB detection circuits 18 are supplied with the AF information to the lens 12 and the aperture / shutter mechanism 13 through the CPU 19 through the CPU 19.
The E information is supplied to the camera signal processing circuit 17 as AWB information.

Reference numeral 20 denotes a compression circuit (J) for compressing the data amount.
(PEG), the image data compressed by the compression circuit 20 is recorded on a removable memory card 26 via a memory card I / F 25. Reference numeral 21 denotes a memory controller, and reference numeral 22 denotes a DRAM, which is used as a working memory when performing color processing or the like of video data. 23 is a display circuit, 24 is an LCD display unit,
These are used to read out and display data recorded on the memory card 26, and to confirm a shooting state. A personal computer I / F 27 is used to transfer data recorded on the memory card 26 to the personal computer 28. Reference numeral 29 denotes a CC that generates a timing pulse and the like for driving the CCD image sensor 11.
D driver, CCD under the control of CPU 19
The image pickup device 11 is driven in various read driving modes. Reference numeral 30 denotes a CCD image pickup device, which includes the second low-pass filter 14-2 of the low-pass filter block 14 and the dummy glass.
This is a filter changer for switching according to the readout drive mode of No. 11. 31 is an aperture / shutter driver for driving the aperture / shutter mechanism 13, and 32 is a strobe mechanism.
It is controlled via the CPU 19 by the AE information. 33 is CP
With the U input key, it is possible to set various read driving modes of the CCD image pickup device, set various photographing modes, drive a trigger switch, and the like.

Next, the configuration of the CCD image sensor 11 will be described. This CCD image pickup device 11 is an interline type C
It is a CD imaging device and has a color filter of Bayer array. As shown in FIG. 2, the Bayer array color filter
R (red) and G (green) filters are alternately arranged on odd lines, G (green) and B (blue) filters are alternately arranged on even lines, and G (green) filters are checked in a whole. It is arranged in a pattern.

As in the case shown in FIG. 7, the CCD image pickup device has a set of 16 pixels 1 in the vertical direction.
They are arranged repeatedly in the vertical direction along the vertical transfer path. Then, two pixels of a vertical transfer path a group and two vertical transfer electrodes of a b group are arranged in correspondence with each pixel of each set, and each pixel is transferred to a group of the vertical transfer path a group via a transfer gate. It is connected to each transfer channel of the vertical transfer path corresponding to the electrode. An independent transfer / transfer pulse application lead electrode is connected to the transfer electrodes of group a so that a gate pulse can be independently applied to each transfer gate in addition to the transfer pulse.

Then, two transfer pulse applying and extracting electrodes corresponding to the transfer electrodes of group b of each transfer electrode and a plurality of transfer / transfer pulse applying and extracting selected from independent transfer / transfer pulse applying and extracting electrodes. A four-phase shift pulse is applied to the electrodes to enable four-phase driving. At the same time, by appropriately applying and supplying a gate pulse to each independent transfer / transfer pulse application extraction electrode, a desired high-speed (double-speed) readout or the like can be performed in the same manner as described above in the section of the prior art. Special driving can be performed.

Next, the low-pass filter block 14 will be described. In the following description of the low-pass filter, the characteristics in the horizontal direction are omitted, and the description will be made based on the characteristics only in the vertical direction. First, the characteristics of the standard first low-pass filter (LPF1) 14-1 in the all-pixel reading mode (interlaced scanning using a mechanical shutter) will be described. In the CCD image pickup device 11 having the above configuration, if the pixel pitch in the vertical direction when the color filter is not considered is p, the sampling frequency of the pixel is 1 / p.
Reference numeral 11 uses a Bayer array color filter, and pixels corresponding to the R and B filters are arrayed at 2p intervals, so that the color sampling frequency of the pixel is 1 / 2p. Therefore, as shown in FIG. 3, the standard first low-pass filter 14-1 required in this case has such a characteristic that the frequency position of the color sampling frequency 1 / 2p becomes a trap point. In FIG. 3, the vertical axis represents the relative response R and the horizontal axis represents the spatial frequency f. When the characteristic of the first low-pass filter 14-1 shown in FIG. 3 is expressed by an equation, R (LPF1) = | Cos (pfπ) |. And actually, it is composed of a crystal having a separation width p or the like. Here, the dummy glass prevents the aberration of the lens 12 from changing as described above, and does not have the filter effect in the present invention.

Next, a low-pass filter required for reading in the double speed addition mode described above with reference to FIG. 8 will be described. At the time of reading in this mode, although the resolution is reduced, a standard first low-pass filter (LPF1) 14 is used.
This is the case where only the use of -1 is sufficient. In this mode, the resolution is reduced by the addition processing, and the resolution has the same frequency characteristics as when a low-pass filter having the characteristics shown by the solid line in FIG. 4 is used. That is, as the information of the pixels to be read in the double speed addition mode readout, the information of all the original pixels is read out, but the pixels located at positions 2p apart are regarded as the same pixel and added on the horizontal transfer path. The color sampling frequency is 1 / 4p. However, at the stage of spatial sampling before addition, all pixels are read and have all pixel information, so that although the resolution is reduced, it does not cause a new pseudo signal. As described above, the spatial sampling frequency is １ ／ shown in FIG.
Since it is not different from p, it is sufficient to use one having the same characteristics as the standard first low-pass filter, and no additional low-pass filter is required. Therefore, at the time of the double speed addition mode reading, in the low-pass filter block 14, a dummy glass is selected and arranged instead of the second low-pass filter 14-2 as in the all-pixel reading mode.

Next, the manner of use of the low-pass filter block 14 in the 2 × non-addition mode and the 4 × speed mode will be described. Strictly speaking, in these modes, the frequency characteristics of each mode are slightly different as a whole. However, when focusing only on the generation of the pseudo signal, that is, focusing on the color sampling frequency, these modes are all 1 / 8p. That is, focusing on the periodic structure of the read pixels, the pixel interval is 8p, and the color sampling frequency is 1 / 8p. In these modes, since the pixel sampling frequency is actually reduced to 1 / 8p as a spatial arrangement, a pseudo signal is generated at this frequency. Therefore, at least 1 /
It is necessary to add a second low-pass filter (LPF2) 14-2 having a characteristic of using a frequency of 8p as a trap point to suppress generation of a pseudo signal. The frequency characteristic of the second low-pass filter 14-2 is a characteristic shown by a solid line in FIG. 5, and when expressed by an equation, R (LPF2)
= | Cos (4pfπ) |. The filter glass is actually made of a crystal with a separation width of 4p, and is additionally arranged as a component of the low-pass filter block 14 by the filter changer 30 via the CPU 19 instead of the dummy glass.

In each of the above modes, 1 / 8p
The additional use of the second low-pass filter (LPF2) having the characteristic of having a trap point at the point satisfies the necessary condition. However, in these modes, the spatial frequency at which color moiré appears strongly is 1 / There is also 4p. In other words, the spatial frequency that is a multiple of 1 / 8p is originally a portion where color moiré is likely to occur.
The low-pass filter having the characteristic that p becomes a trap is 1/8
It is more preferable to use a combination of a low-pass filter having a characteristic in which p becomes a trap as the second low-pass filter 14-2.

[0037]

As described above with reference to the embodiments, according to the present invention, there is provided the imaging characteristic switching means for switching the spatial frequency characteristic of the image pickup optical system according to the drive mode. In addition, it is possible to effectively suppress a pseudo signal generated due to a change in the spatial sampling characteristic due to the driving mode of the image sensor.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an electronic camera using a CCD image pickup device according to an embodiment of an image pickup apparatus according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a Bayer array color filter.

FIG. 3 is a diagram illustrating a spatial frequency characteristic of a standard first low-pass filter included in the low-pass filter block according to the embodiment illustrated in FIG. 1;

FIG. 4 is a diagram showing a spatial frequency characteristic representing a decrease in resolution when the CCD image pickup device is driven in a double speed addition mode in the embodiment shown in FIG. 1;

FIG. 5 is a diagram showing a spatial frequency characteristic of a second low-pass filter additionally required when the CCD image pickup device is driven in the 2 × non-addition mode and the 4 × speed mode in the embodiment shown in FIG. 1; .

FIG. 6 is a diagram showing a configuration of a vertical transfer path portion of a conventional interlaced CCD image pickup device having a 16-pixel unit 4-phase drive configuration.

FIG. 7 is a diagram showing a configuration of a vertical transfer path portion of a CCD image pickup device capable of special driving such as double-speed reading of a conventional 16-pixel unit four-phase driving configuration.

FIG. 8 is a diagram illustrating a reading mode in various reading modes that can be read using the CCD imaging device having the vertical transfer path illustrated in FIG. 7;

9 is a timing chart for explaining a read operation mode in a one-field two-time read mode without using a mechanical shutter in the CCD image pickup device having the vertical transfer path shown in FIG. 7;

[Explanation of symbols]

 1 pixel 2 vertical transfer path 3 transfer gate 4 shift pulse applying lead electrode 4A transfer / transfer pulse applying lead electrode 4B transfer pulse applying lead electrode 5, 6 lead electrode input terminal 11 CCD image sensor 12 lens 13 aperture / shutter mechanism 14 low pass filter Block 14-1 First low-pass filter 14-2 Second low-pass filter 15 Pre-processing circuit 16 A / D converter 18 Camera signal processing circuit 18 AF, AE, AWB detection circuit 19 CPU 20 Compression circuit 21 Memory controller 22 DRAM 23 Display Circuit 24 LCD Display 25 Memory Card I / F 26 Removable Memory Card 27 Personal Computer I / F 28 Personal Computer 29 CCD Driver 30 Filter Changer 31 Aperture / Shutter Driver 33 Strobe Mechanism 33 Input Key

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C024 AA01 CA05 DA01 EA04 EA08 FA01 GA16 GA22 HA06 JA21 5C065 AA01 BB13 CC01 CC09 DD07 EE06 EE14 GG11

Claims (3)

[Claims] An imaging optical system; an imaging characteristic switching unit for switching a spatial frequency characteristic of the imaging optical system; a charge transfer type imaging device for photoelectrically converting an output image of the imaging optical system;
Driving means for driving the charge transfer means of the image sensor in a plurality of selectable drive modes; and read control means for reading image signals from the image sensor by driving at least the drive means in a predetermined drive mode. An imaging apparatus, wherein the imaging characteristic switching unit is configured to switch a spatial frequency characteristic of the imaging optical system according to the drive mode. 2. The read-out control unit according to claim 1, wherein the read-out control unit controls the output of an output image of the imaging optical system by driving an optical shutter, or a read-out driving mode for a moving image without driving the optical shutter. The driving means is selectively controlled to be driven in a mode, and the imaging characteristic switching means changes a spatial frequency characteristic of the imaging optical system in accordance with a read driving mode selected by the reading control means. The imaging apparatus according to claim 1, wherein the imaging apparatus is configured to switch. 3. The imaging characteristic switching unit according to claim 1, wherein the imaging characteristic switching unit switches the spatial frequency characteristic of the imaging optical system by switching an optical low-pass filter. Imaging device.