JPS60130974A - Image pickup device - Google Patents

Abstract

PURPOSE:To eliminate a tailing phenomenon by providing a rotary shutter mechanism having a slit shutter plate inserted in an optical path reaching to an image pickup element from an optical system and a member reflecting light incident to a photometric element. CONSTITUTION:A CCD drive circuit 92 receives a synchronizing signal from a synchronizing signal generating circuit 91 and applies a sensor gate pulse SG to a CCD80. Its output is amplified by a preamplifier 93 and transmitted from a terminal 95 via a video signal processing circuit 94. A shutter plate slit position detecting circuit 98 of a rotary shutter mechanism receives an output of a slit position sensor 99, differentiates it and forms a shutter full open pulse and gives it to a motor servor circuit 96 and a strobe control/photometry circuit 100. The photometry element 103 integrates a reflected light from an object 104 during lighting of a strobe and applies an output to the circuit 100. A direct photometry element 105 connected to the circuit 100 receives a reflected light from a reflecting member 106 and applies its integration output to the circuit 100.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an imaging device such as an electronic camera or a TV camera, and in particular to an optical system and an imaging device that converts an image obtained by the optical system into an electrical signal. The present invention relates to an imaging device in which a shutter mechanism having a shutter plate with slits for exposing the above-mentioned element [2] is inserted in the optical path, and a photometric element is provided between the shutter mechanism and the optical system.

[Prior art]

In general, NT is used for imaging devices such as electronic cameras and TV cameras.
Standards such as SC, PAL, and SECAM are applied. For example, in an NTSG standard imaging device, an optical image is stored in an image sensor for 1/30 seconds or 1/60 seconds, and the accumulated charge is scanned with an electron beam. The structure is such that the image signal corresponding to the optical image is extracted by discharging the image signal.

Therefore, when the subject is a fast-moving object, or when the camera is used in a vanishing manner, a "tailing phenomenon" occurs on the screen, blurring the image and degrading the image quality. The causes of such image quality deterioration include accumulation effects and afterimages.

The accumulation effect is the effect of accumulating the amount of light for one frame on the photoelectric conversion surface of the image sensor, increasing the image transport sensitivity,
Although this is an effective means of improving the S/N ratio, it can also be said to be isometrically imaging using a slow shutter speed of about 1/3o second, so the image may become blurred due to high-speed moving objects or camera shake, resulting in a decrease in image quality. become.

On the other hand, afterimages are caused by residual charges that cannot be discharged by one electron beam operation, but recently, solid-state image sensors have been made to have low afterimages.
It can be said that this is a problem that has been resolved.

Therefore, in order to solve the image quality deterioration, it is necessary to remove the influence of the accumulation effect. For this purpose, it is effective to shorten the light accumulation time, and devices using shutters such as conventional devices are known for this purpose.

That is, this shutter has a rotating disk that blocks light installed in front of the image pickup tube, and the speed at which one or more openings or notches provided in this rotating disk cross the imaging surface and the image scanning speed (usually By synchronizing the time interval (1/60 seconds per screen), an instantaneous still image can be obtained without capturing the tail part of the screen.

However, the above-mentioned shutter was developed only for the purpose of obtaining still images and was only used for special business use, and had the disadvantage of being a high-cost and large-sized device. Furthermore, even when the shutter function is not required, the shutter function cannot be released and normal video shooting cannot be performed.

In this regard, as a means for releasing the shutter, as shown in Japanese Utility Model Application Publication No. 57-15572, the aperture slit is made larger than the area of the photoelectric conversion surface, and the aperture is placed at a position where the aperture overlaps the photoelectric conversion surface. There is a way to keep the opening fixed. However, with this method, it is necessary to make the opening slit on the disk sufficiently large. For example, when using a 2/3-inch image pickup tube or image sensor, the slit opening should be 8 x 10 #ll! <There is a need to treat leprosy.

As a result, the diameter of the shutter disk becomes large, making it impossible to implement a compact mounting. It is also necessary to increase the power of the motor for driving the rotation of the shutter disk. Furthermore, even when using the shirt seed, power must be supplied to the motor, so it is not suitable for a battery-powered portable type imaging device. As another means of releasing the shutter,
There is also a method in which the slit part of the disc is positioned at the shutter OFF position by motor drive, and then the slit part is fixed at that position by a mechanical method.
It is necessary to bring the disk rotating at 00 RPM to low speed rotation in a short time, position the slit portion, and then fix it, and the structure is complicated and highly accurate operation cannot be expected.

Further, in the conventional apparatus having the above-mentioned configuration, the light incident on the image sensor is not photometered to perform proper exposure, and therefore there is a risk of image quality deterioration.

〔the purpose〕

An object of the present invention is to provide an apparatus that is capable of obtaining clear still images with less blur and without blurring of images due to the "tailing phenomenon" even if the subject is a fast-moving object. In addition to being able to release the shutter according to
An object of the present invention is to provide an imaging device capable of photometrically measuring light incident on a 111 element and performing appropriate exposure.

(Summary) In order to achieve the above object, the present invention is characterized by the following configuration. That is, a shutter has a shutter plate with a slit in the optical path between an optical system attached to an imaging device and an imaging element that converts an image obtained by the optical system into an electrical signal, and which exposes the imaging element. A mechanism is provided so that the mechanism can be inserted at a suitable time, and a photometric element is provided between the shutter mechanism and the optical system, and the light that is incident on the photometric element through the optical system is reflected by a reflecting member and is incident on the photometric element. It is characterized by what it did. The reflective member preferably has a photometric reflective surface with a substantially flat spectral reflectance distribution in the wavelength range of the light used, and is preferably provided on the light-shielding portion of the shirt shirt plate or the holding frame of the image sensor.

〔Example〕

Figures 1 to 23 are diagrams showing one embodiment of the present invention.
The figure is an external perspective view of the video camera.

1 in FIG. 1 is a video camera body serving as an imaging device.

2 is an optical system including a plurality of optical lenses; 3 is a grip; 4
is a cable, 5 is a viewfinder, 6 is a microphone, and 7 is an operation panel. A manual knob 8, which will be described later, is attached to the side wall of the operation panel 7. During photographing, the object captured by the optical system 2 is converted into an electrical signal by a solid-state image sensor (described later) housed in the camera body 1 coaxially with the optical system 2, and then transmitted via a cable 4 (not shown). The image is sent to a video monitor or VTR and displayed.

FIG. 2 is a cutaway diagram showing the main parts of the video camera shown in FIG. 1. In the figure, 10 is a frame of a video camera, and the optical system 2 is fixed to this frame 10.

The image pickup device 1 is arranged so that the light receiving surface 11a faces the final end master lens 2a of the optical system 2 at a predetermined distance.
1 is arranged. 12 is a rotary shutter mechanism, and this rotary shutter mechanism 12 has a lever plate 1.
A main body part consisting of a motor, a shirt flap plate with slits, etc. is attached to the tip part of 3. As will be described later, the lever plate 13 has its center portion rotatably supported by the frame 1O, and its base end connected to the manual knob 8.
By operating this, the distal end portion to which the main body portion is attached can be rotated within a predetermined angular range. Motor 1
4 is fixed to one side of the distal end portion of the lever plate 13, and its rotating shaft 15 protrudes from the other side of the lever plate 13. Bosses 16.17 are fitted into the rotating shaft 15, and the slit shirt shirt plate 2O is attached with the shaft center supported by these bosses 16.17. The shirt shirt plate 2O with slits is the first. It is composed of a second disc with slits 21 and 22, and the lever plate 1
When the rotary shutter device 1j112 is rotated to the first position in response to the rotation of 3, the slit portion is located between the master lens 2a of the optical system 2 and the light receiving surface 11a of the image pickup device 11, as shown in the figure. It is inserted into the optical path and performs the exposure operation using the slit section. Also lever plate 1
When the O-tally shutter 111112 is rotated to the second position in response to the rotation of 3, it escapes from the optical path to the outside. The first slitted disc 21 is rotatably fitted into the boss 16, and the second slitted disc 22 is unrotatably fitted into the boss 17.

3 and 4 are plan views of the first slitted disc 21 and the second slitted disc 22. FIG. As shown in FIG. 3, the first slitted disc 21 has fan-shaped notches 21a and 21b of the same shape at opposing positions that are different by 18σ on the disc part made of a light shielding member. , locking pieces 21c and 21d bent perpendicularly to the plane of the disc part are provided at the base of each one side edge of the cutout part 218.21b. Further, as shown in FIG. 4, the second slitted disc 22 has a fan-shaped notch 21a of the first slitted disc 21 at a position opposite to the disc part made of the light shielding member, which is 180 degrees different from the other.
, 21b, and has notches 22a and 22b having the same shape as the notches #22a and 22b, and the shirt flap plate 20 comes into contact with the locking pieces 21c and 21d at the root portion of each side line portion in the notches #22a and 22b when rotated in the normal rotation direction. Protrusions 22G and 22d are provided as first contact portions that can be contacted. Note that notches 22a and 22b opposite to protrusions 22c and 22d
The other side edge portions of the shutter plate 2O are second contact portions that come into contact with the locking pieces 2IC and 21d when the shirt shirt plate 2O rotates in the reverse direction.

5 and 6 are views showing the state in which the first and second slitted discs 21, 22 are stacked with the first slitted disc 21 facing down.

FIG. 5 shows a locking piece 21c of the first slit disk 21.
, 21d, the protruding piece 22c of the second slit disk 22
, 22cf are in contact with each other. In this state, the notches 21a and 22a and the notches 21b and 2
2b is a locking piece 21c.

21d and the width of the projecting pieces 22c and 22d. M2
form.

FIG. 6 shows that by rotating only the first slit disc 21 in the counterclockwise direction from the state shown in FIG. When the left side edge of the notch 22a in the figure comes into contact with the notch 22a,
2 shows a state in which the right side edge in the figure of the notch 22b of the second disc 22 with slits is in contact with the locking piece 21d of the first disc 21 with slits. In this state, each notch 2
1a and 22a and 21b and 22b respectively overlap each other, and a second slit N1. Forms N2.

Note that the slits M1 and M2 in the state shown in FIG.
The width of slit N1 and the condition shown in Fig. 6
．． How to set the width of N2 will be described later.

Next, as described above, the shutter plate 2O is inserted into the optical path to perform intermittent exposure to obtain a still image, or removed from the optical path to perform normal video shooting, and a switching mechanism and variable slit width are provided. The mechanism will be explained.

FIGS. 7 and 8 are diagrams showing the configuration and operation of the switching mechanism and the variable slit width mechanism. The manual knob 30 shown at the left end in FIGS. 7 and 8 has an operating protrusion 30a at the center of one side of a disc-shaped base, and locking protrusions 30b and 30C on both upper and lower end faces in the figures. have. Further, the manual knob 30 has an engagement groove 306 in the center of the other side of the disc-shaped base. The operating protrusion 30a and the locking protrusions 30b, 30C of the manual knob 3O can selectively engage holes 7a, 7b, 7C provided in the operating panel 7.

That is, as shown in FIG. 7, the operating protrusion 3
As shown in FIG.
Two states can be selected: a state in which the operation projection 30a and the locking projection 30b engage with the hole 7c, and a state in which the locking projection 30c engages in the hole 7c. Manual knob 3 above
The other side of 0 is covered with a holding cover 31. Springs 32a and 32b are inserted in a compressed state between the inner bottom surface of the holding cover 31 and the bottom surface of the disc-shaped base of the manual knob 30, and press the manual knob 30 against the inner wall surface of the operation panel 7 at all times. ing. The springs 32a and 32b are fixed to the manual knob 3O side and are provided in a slidable manner on the inner bottom surface of the holding cover 31.

A pin 33 provided at the base end of the lever plate 13 is engaged with an engagement groove 306 provided at the center of the bottom surface of the disc-shaped base of the manual knob 30 . As shown, the lever plate 13 is fan-shaped, and its central portion is pivotally supported by a pivot 34, which allows it to rotate around the pivot 34. As already mentioned, the main body parts of the rotary shutter mechanism 12, such as the motor 14 and the shutter plate 20, are fixed near the tip of the lever plate 13. Further, a pair of square holes 35a and 35b are provided at the tip end of the lever plate 13. These holes 35a and 35b are provided with locking balls 36 provided in the frame 10 when the lever plate 13 is rotated.
The lever plate 13 selectively engages with the lever plate 13 to specify the rotational position of the lever plate 13. In addition, the above-mentioned locking ball 3
6 is supported by a guide 37 and pressed against the lever plate 13 by a spring (not shown).

Although not shown, when the lever plate 13 rotates to the state shown in FIG. 7, it turns ON and rotates the motor 14, and when the lever plate 13 rotates to the state shown in FIG. 8, it turns OFF. A microswitch is provided to stop the rotation of the motor 14. Further, the operation panel 7 is provided with a rotation direction designation switch for specifying whether to rotate the motor 14 in the normal direction or 7) in the reverse direction.

In this way, when performing intermittent exposure photography, if the rotation direction designation switch is changed according to the illuminance of the subject, etc., and the manual knob 3O is set to the position shown in FIG. 7, that is, the operating protrusion 30a of the manual knob 3O is pushed in. When the lever plate 13 is then slid upward in the figure, the lever plate 13 rotates clockwise in the figure, and the square hole 35a provided at the tip of the lever engages with the locking ball 36. By releasing your hand from the manual knob 3O when you feel a click feeling due to this engagement, the manual knob 3O is released from the springs 32a and 3.
2b returns, the locking protrusion 30b engages with the hole 7b of the panel 7, and the locking protrusion 30c engages with the hole 7a of the panel 7.
to intervene. As a result, the slit portion of the shirt cover plate 20 is inserted into the optical path as shown in FIG. At the same time, microswitches etc. are turned on. Now, assuming that the forward rotation direction is designated by the rotation direction designation switch, the motor 14 starts to rotate forward, so the shirt starter plate 20
starts rotating in the direction indicated by the arrow in FIG. At this time, since the first slitted disc 21 is mounted almost freely with respect to the rotating shaft 15, only the rotational force generated by the friction resistance valve with the boss 16 is applied. Moreover, the locking pieces 21c, 2
Since 1d is subjected to air resistance, this acts as a rotational braking force. Therefore, the first disc 21 with slits rotates slower than the second disc 22 with slits, rotates relatively clockwise in FIG. 7, and the locking piece of the first disc 21 with slits 21c and 21d are the projecting pieces 22 of the second slit disk 22
It exhibits a state of stable contact with C and 22d. Therefore, the slit portion is a narrow slit M1. as shown in FIG. It becomes M2.

The time required for one rotation of the disc 21 and 22 with both slits is
A slit crosses the front surface of the light receiving surface 11a of the image pickup tube 11,
The time it takes for the next slit to cross the same spot is 16.6
7 m5, and in the case of this device, the slits are provided at two locations, so the time required for one rotation is 16.67 x 2 = 3a, 34 ms (equivalent to 1800 rpm).

Further, assuming that the reverse direction is designated by the rotation direction designation switch, the motor 14 starts rotating in the reverse direction.

Then, the shirt top plate 20 begins to rotate in the direction opposite to the arrow in FIG. Therefore, contrary to the above case, the first slitted disc 21 is connected to the second slitted disc 22.
It rotates counterclockwise in FIG. 7 relative to the other direction. Therefore, the locking pieces 21C and 21d are attached to the second slit disk 22.
It comes into contact with the other side edges of the notches 22a and 22b. As a result, a wide slit N1. shown in FIG. It becomes N2.

By rotating the rotation direction of the motor 14 in the forward or reverse direction in this manner, the slits M1. The light passing through each slit can be incident on the light-receiving surface 11a of the image sensor 11. In other words, intermittent exposure photography with two types of exposure amounts can be performed. Note that the rotation time described above is detected by a rotation sensor (not shown), and the shirt shirt plate 2O is stably controlled to rotate by a control system (not shown).

Next, when performing normal continuous exposure photography, use the manual knob 30.
Set it to the position shown in Figure 8. (that is, manually), then slide the button 3O downward in the figure while pushing it in. Then, the lever plate 13 rotates counterclockwise in the figure,
The hole 35b at the tip of the lever engages with the locking ball 36.

When you feel a click due to this engagement, the manual knob 3
0, the manual knob 30 returns due to the force of the springs 32a and 32b, the locking protrusion 30b engages with the hole 7a of the panel 7, and the locking protrusion 3Od fits into the hole 7C of the panel 7. It becomes an involved state. As a result, the shutter plate 2O moves upward in the figure as shown in FIG. 8, and is completely removed from the optical path. In this state,
A microswitch (not shown) operates, and the power to the motor 14 is cut off. Therefore, the rotation of the shirt shirt plate 2O also stops.

In this way, the light receiving surface 11a of the image sensor 11 has 10
0% of the light will be incident, and normal video shooting using continuous exposure can be performed.

If you perform the above operation in reverse, rotary shutter mechanism 1
2 transitions from the state shown in FIG. 8 to the state shown in FIG. 7, and the microswitch is turned on, so that the motor 14 rotates in the forward or reverse direction in the state shown in FIG. In this way, the two discs 21 and 22 with slits rotate forward or backward, and still images can be taken again by intermittent exposure with two different slit widths.

Next, the slit M1 mentioned above. How to set the widths of M2 and N1°N2 will be explained.

First, slit M1. The width of M2 is set based on the following points of view. In order to obtain a clear still image of a fast-moving object in the middle of its motion in a video camera, a narrow slit M1, M2 is provided between the optical system 2 and the image sensor 11, as shown in FIG. Interposing the shirt flap plate 20, rotating it clockwise or counterclockwise,
It is necessary to expose the light-receiving surface 11a at a speed sufficiently faster than the image scanning speed of the image sensor 11. The faster the exposure speed, the clearer the still image can be obtained.
On the other hand, the exposure amount will decrease.

If the total exposure amount becomes too small, the sensitivity of the image sensor 11 will fall below its capability, making it impractical. On the other hand, when the exposure speed is decreased in order to increase the total exposure amount, beam readout of the image sensor 11 and exposure are performed at the same time, and as the exposure speed becomes slower, a striped pattern gradually appears from the outside of the top and bottom of the TV screen. This will result in poor image quality.

Therefore, an appropriate exposure time t when using the shirt plate 20 is set as follows. As shown in Figures 9 and 10, the period T of one field (1/60 = 16.67 m5
) corresponds to the length in the circumferential direction on the shirt shirt plate 20, then T becomes A+8.

A is the dark part, and B is the width of the light receiving surface 11a and the slit N.
1 or the sum of the width of N2. Now, assuming that the effective area of the TV screen is 80-85%, B/ (A + 8) - 8/1
6.67-(100-(80-85))/100. In other words, if the effective area is 80%, B-3°33m5. When the effective area is 85%, B=2.5 ms. Therefore, when the imaging means is an image pickup tube, it is appropriate to set the exposure time t to about 2.5 to 3 ms since it is necessary to complete the exposure within the blanking time.

Images taken with a video camera equipped with a rotary shutter device configured based on the above will have insufficient exposure compared to normal shooting, but by using a high-sensitivity image pickup tube, for example, images taken under sunlight can be The captured images are clear enough to be used for practical purposes.

Next, slit N1. The width of N2 is set based on the following points of view. As mentioned above, if the state shown in FIG. 5 is used, insufficient exposure may occur.

Therefore, in order to cope with the case where it is necessary to increase the exposure amount even if the image quality is slightly inferior, for example, the slit width can be changed from the state shown in FIG.
It is conceivable to expand this to

However, in the case of (b) above, the entire two-dimensional and four-dimensional photoelectric conversion surface cannot be exposed simultaneously, so strobe photography cannot be performed while the shutter is in use.

Therefore, as shown in FIG. 11(C), the slit width is made slightly larger than the width W of the light receiving surface of the image sensor 11. In other words, a shape that can encompass the entire effective light-receiving surface of the m-image element 11.
It shall have dimensions.

If the strobe light is emitted when the slit N1 or N2 is in the state shown in FIG. 11(C), the entire light-receiving surface will be illuminated at the same time, making it possible to take pictures using strobe exposure. However, as already mentioned, the total light time is
The length is longer than that shown in FIGS. 1(a) and 1(b), and there is a risk that the freeze characteristics will deteriorate and the image quality will deteriorate.

By the way, if an X-Y address type MOS [i-body m image element] is used as the image sensor 11, since this is of a so-called point-sequential readout method, the total optical time E
When t exceeds 3 ms, considerable image quality deterioration occurs. That is, in the case of an XY address type MO8 type solid-state image sensor, as shown in FIG. 12(a), when exposure is possible, filT1 is limited to only within or before and after the vertical planking time. Therefore, there is an upper limit to the width of the slit and the total exposure time Et, and if this upper limit is exceeded, a portion of the screen will be degraded in image quality due to the non-uniformity of the exposure FRWR. However, frame transfer type and incline type C
In the case of an OD device that has a bulk charge transfer function and a light-shielded transfer shift register, non-uniformity in exposure [47] does not occur, except for image quality deterioration due to subject movement. However, if such an element is used, Figure 12 (b
), the exposure time can be set as T2.

Note that, as described above, if exposure is performed outside the allowable exposure time depending on the type of image sensor, image quality will deteriorate. This point will be explained below.

Figures 13(a), (b), (c), and (d) show exposure when using an optical signal charge/point sequential transfer system, such as an MO8 type X-Y address system solid-state image sensor, as the Wi image element. FIG. 6 is a diagram showing a pattern of image quality deterioration due to exposure outside the possible time. Also, Fig. 14 (a) (b) (c) (d)
4; Frame transfer type COD as &l1m1 child
Alternatively, it is a diagram illustrating a case in which image quality deteriorates due to exposure outside the available exposure time when a solid-state image sensor of an optical signal charge/batch transfer type, such as an incline type COD, is used. In addition, FIGS. 13(a) to (d) and FIG. 14(a)
~(d) In each case, when shutter exposure is performed only once with the optical path blocked by the shutter and a white surface is imaged, the image quality deteriorates due to the relationship between the operation timing of the image sensor and the shutter timing. This shows how this occurs.

As shown in FIGS. 13(a) and 13(b), when the shutter opening 42 is located with respect to the photoelectric conversion surface 41, the driving timing of the element is exactly at the direct blanking period as shown by the broken line in the figure. , when shutter exposure is performed at time tA, which is halfway between the next vertical blanking period, the read image signal becomes as shown in Fig. 13 (C), and on the monitor screen it appears as shown in Fig. 13 (d). . The reason for this is that the photo-accumulated charge generated by exposure is divided into two fields with the position during reading as a boundary. Therefore, when using an optical signal charge/point sequential type imaging device, it is necessary to keep the exposure timing of the shutter within the vertical blanking period. However, the vertical blanking period is approximately 1 ms, and it is difficult to complete the exposure within this period due to the responsiveness of the mechanism and the total amount of exposure. Therefore, in practical terms, approximately 1 of the vertical blanking period is
Approximately 1 ms from the tail end of the previous field across ms.

A total of 3 ms, including 1 ms at the beginning of the next field, may be used as the shutter exposure time.

That is, the period of 1 ms before and after the vertical blanking period is not used as a display area on a general monitor TV, and even if it is used for display, the effect is extremely small because it is m80 of the screen.

On the other hand, as shown in FIGS. 14(a) and 14(b), when the shutter opening 52 is at the illustrated position with respect to the photoelectric conversion surface 51, the driving timing of the element is within the vertical blanking period as shown by the broken line. At time tB, the waveform of the read image signal in each horizontal period is shown in FIG. 14(C).
The monitor screen will look like (d) in the same figure.
Image quality deteriorates. The reason for this is that while the right half of the photoelectric conversion surface 51 has been exposed to light with respect to the line at time tB, the exposure of the left half has not yet been completed, and in this state, the batch transfer of optical signal charges is not completed. This is because it has already been done. Therefore, when using the optical signal charge/batch transfer type imaging device, the shutter exposure timing must be set to a period excluding the vertical blanking period and its vicinity.

Generally speaking, in the case of interline type COD, image quality deterioration occurs when transfer pulses (SG pulses) are output during exposure, and in the case of frame transfer type COD, frame transfer occurs during exposure. Shifting results in image quality deterioration. Therefore, in both the interline method and the frame transfer method, exposure by the shutter cannot be performed during the vertical blanking period and a time period of several milliseconds including the period before and after the vertical blanking period. For example, it takes 3 m to complete the exposure of all pixels.
When using a shutter that requires S, 3 mm between the vertical blanking period becomes an exposure prohibition time.

As is clear from the above explanation, the exposure timing by the shutter needs to be changed depending on the type of the m-element used.

Next, the relationship between the shutter and the optical signal charge/batch transfer type solid-state imaging device will be explained. Regarding this type of image sensor, for example, CARLOH.

Frame transfer type COD or interline transfer type CO as shown in pages 140 to 144 of ``Charge Transfer Device'' by 5EQUIN (Kinda Kagakusha 1978)
There are D, etc.

FIG. 15(a) is a diagram showing a frame transfer type CCDl1 image element 6O. In this element 6O, the optical storage section 6 during frame time or field time
The optical signal charges integrated at 1 are collectively transferred to the light-shielded signal storage section 62 within the vertical blanking time. The collectively transferred optical signal charges are transferred to a horizontal shift register 63.
is sent to the output amplifier 64. Therefore, the period other than the batch transfer within the vertical blanking time, that is, the 12th
Exposure can be performed using a shutter during the T2 period shown in FIG. 3(b).

On the other hand, FIG. 15(b) is a diagram showing an interline transfer type CCOM image element 7O. In this element 70, the optical signal charge integrated by the photoelectric conversion element 71 during the frame time or field time is a gate signal applied to the transfer gate 72, and is transmitted to the light-shielded vertical The data is transferred all at once to the transfer unit 73. The collectively transferred optical signal charges are then sent to the output amplifier 75 by the horizontal shift register 74. Therefore, in this element 70 as well, exposure can be performed using the shutter during a period other than the batch transfer, that is, during the T2 period in FIG. 12(b).

In other words, in a solid-state image sensor using the batch transfer method,
Unlike Y-address type solid-state image sensors, it does not use a dot-sequential readout method where the light accumulation time and readout time are mixed within the screen.
The light accumulation time is temporally independent for about one screen type. Therefore, period T2 (approximately 15m5) other than the blanking time
) is used for exposure without causing image quality deterioration. Therefore, when a batch transfer type image sensor is used, there is little deterioration in image quality even if a relatively large-area slit is provided on a small disk.

Next, let's take a look at a specific numerical example of the highest shutter speed that can be used, for example, when photographing with delight synchronization.

In FIG. 16, the radius of the shutter disk 2O is rl, and the radius from the center of the disk 20 to the center of the image sensor 11 is r.
2. The radius from the center of the disk 20 to the bottom of the slit is r3. The slit width at the point of radius r2 is S, 11! The volumetric size of the image element 11 is D, and the number of rotations of the disk is n (RPS
), the line exposure time Et is Et-(D+8)/(2πr2xn) (where D≦S). Considering a 273-inch element, D=8
．． It is 8m. Assuming two slits are provided, n=30R
Assuming that Ps, r 2-23m+, and S-12mm, Et=4.8ms, resulting in a shutter of about 1/200 sec.

In other words, it is possible to perform delight synchro photography with a shutter speed of 1/200 sec. If the slit width S is made larger than in the above case, a slower shutter speed can be obtained. The shutter speed that can be synchronized with the strobe of the focal brain shutter of a normal silver halide camera is MAX 1/60se.
Considering that it is c., it can be said that the performance is sufficient.

FIG. 17 shows a specific example of the image sensor 11 used in this apparatus, and shows interline transfer 1ccD80.

In the figure, reference numeral 81 denotes a photoelectric conversion element having color filters R, G, and B on its surface, each forming one pixel. A vertical shift register 82 made of COD is provided adjacent to the photoelectric conversion element 81. These vertical shift registers 82 receive optical signal charges accumulated in the photoelectric conversion elements 81 and sequentially transfer them to a horizontal shift p register 83 made of COD. The horizontal shift register 83 transfers the optical signal charges to the output section 84 at one horizontal scanning degeneracy level. Output section 84
has a built-in preamplifier that amplifies a minute current and outputs it from the output terminal Vout. Note that each input terminal of the image sensor 11 receives a sensor gate signal SG, a vertical register transfer lock φV1. φV2. Horizontal register transfer locks φV1, φV2, etc. are supplied from a COD drive circuit (not shown).

The light accumulation time in each photoelectric conversion element 81 is determined based on the timing of transferring charges from the photoelectric conversion element 81 to the vertical shift register 82.

FIG. 18 is a diagram showing a part of the above-mentioned FIG. 17. As is clear from this figure, the sensor gate 85 is a common electrode formed in common to each photoelectric conversion element 81. In addition, the vertical shift registers 82 are arranged alternately, with those that work effectively in odd fields as shown by thin arrows, and those that work effectively as shown by thick arrows in even fields, and transfer locks are provided for each group. φ■1
°φV2 is commonly supplied.

Thus, the optical signal charge/batch transfer is performed as follows. That is, when the potentials of each part in FIG.

■When the sensor gate signal SG is rLJ and φV1 is f'HJ in an odd field ■When the sensor gate signal SG is rLJ and φV2 is rHJ in an even field Therefore, the sensor gate signal SG changes from H level to L level. The changing point is the point at which bulk transfer of accumulated optical signal charges starts, and also the starting point of new optical accumulation.

FIG. 19 is a time chart showing the above timing. In FIG. 19, VD is the vertical drive pulse, H
D is a horizontal drive pulse.

The numbers written on the HD correspond to horizontal scanning line numbers "1 to 525". The sensor gate signal SG changes rl-1J and rLJ once per field. rL above
At the timing of the change in J, the photoelectric charge of the photoelectric conversion element 81 is
It is transferred to vertical shift register 82. In other words, at this timing, the information of all the pixels of the field is transferred into the vertical shift register 82. φv1. φV2 is 2
As well as being a phase vertical register transfer lock, it is also involved in transferring charge from the pixel to the vertical shift register 82. That is, in the first field, when SG becomes rLJ in the 11th H, φV1 becomes rHJ, so at this point, the charges of all pixels related to the image output in the first field are transferred to the vertical shift register 82. Ru. This charge is 1 as a video signal from the 1st H of the ccD output signal.
It is output for 6m5. On the other hand, in the second field, 27
Since φV2 is rHJ at the timing when the sensor gate signal SG becomes rLJ at the 5th H, the charges of all pixels related to the image output in the second field are transferred to the vertical shift register 82 at this time. The transferred optical signal charge is outputted as a video output from the first H after "register empty feed" in FIG. 19 as a COD output signal by the transfer operations of the vertical shift register 82 and the horizontal shift register 83.

In addition, in FIG. 19, the flit image element 8O is used for 2 fields 1
Although the case of driving in the read mode of the frame mode is shown, batch transfer can be similarly performed in other read modes.

Thus, if the two-dimensional solid-state image sensor 80 as shown in FIGS. 17 to 19 is used, as described above,
) It becomes possible to perform exposure within the T2 period.

Next, a control system for performing delight synchronized photography will be explained.

FIG. 20 is a diagram showing a control circuit for delight synchronized photography, and FIG. 22 is a timing chart thereof.

Reference numeral 80 in FIG. 20 is the interline type COD shown in FIGS. 17 to 19. Further, 2O is a per-field shutter disk of the rotating disk type shown in FIGS. 2 to 8,
The slits are two thin films located at 180° different positions on the shutter disk 20. The number of revolutions of the shutter disc 20 is 1
It is 800 RPM.

In FIG. 20, 91 is a synchronization signal of HD, VD, etc.
This is a synchronization signal generation circuit that generates the system clock. C.O.
The D drive circuit 92 operates in response to the synchronization signal from the synchronization signal generation circuit 91, and operates to generate φV1, φV2, . φH1, φH2
, sensor gate pulse SG is supplied to CCD80 and CC
Drive D80. The output of CCD80 is preamplifier 93.
After being amplified by the video signal processing circuit 94, the signal is output as a video signal and sent from the terminal 95.

Among the synchronization signals, the VD pulse is transmitted to the motor servo circuit 9.
6 is also output. The motor servo circuit 96 receives setting signals including forward/reverse rotation command signals from the shutter speed setting circuit 97 and PG pulses from the slit position detection circuit 98, and simultaneously performs continuous servoing of the shutter disc drive motor 14. As shown in FIG. 22, phase servo is performed so that the time interval T between the VD pulse and the PG pulse is constant. The slit position detection circuit 98 receives the output signal of the slit position sensor 99 and differentiates it to detect the change point, creates a shutter full open pulse (PG pulse), and outputs it to the servo circuit 96 and the strobe control/photometering circuit 100. do. The strobe control/photometering circuit 100 is
When the PG pulse is input, a strobe lighting circuit is output to the strobe lighting circuit 101 after a certain timing. A strobe lighting circuit 101 lights a strobe lamp 102. A photometric element 103 connected to the strobe control/photometering circuit 100 integrates the reflected light from the subject 104 while the strobe is on, and outputs the integrated output to the strobe control/photometering circuit 100. When the integrated output exceeds the appropriate exposure level TH, the strobe control/photometering circuit 100 outputs an OFF signal to the strobe lighting circuit 101. A direct photometry element 105 is also connected to the strobe control/photometry circuit 100. The direct photometry element 105 is provided between the above-mentioned optical system 2 and the CCD 80, and collects the reflected light from the CCD 80 and the reflection from the reflection member 106 having a spectrally neutral reflection surface provided in the light shielding part of the shutter disk 2O. It receives light and provides its integrated output to the strobe control/photometering circuit 100. Strobe control/photometering circuit 100
outputs an OFF signal to the strobe lighting circuit 101 when the output of the direct photometry element 105 exceeds Tl-1.

Output signals to the AGC circuit or auto-iris circuit are also output from terminals 107 and 108 of the strobe control/photometering circuit 100.

FIG. 21 is a diagram showing the configuration of a control system during normal photographing without strobe exposure, and FIG. 23 is a timing chart thereof. The circuit shown in FIG. 21 differs from the circuit shown in FIG. 20 in that the strobe control/photometering circuit 100 is simply a photometering circuit, and its output signal is supplied to the shutter speed setting circuit 97, which turns the strobe light on. circuit 101
．． Strobe lamp 102 is omitted. Changing the circuit from FIG. 20 to FIG. 21 or vice versa can be easily done by using a changeover switch or the like. 21st
Since the basic operation of the circuit shown in the figure is the same as that shown in FIG. 20, the explanation will be omitted.

As described above, according to the present device, it is possible to perform strobe photography when using the shutter. In addition, with one video camera, it is possible not only to shoot normal moving pictures but also to shoot still images using two types of intermittent exposure. Further, even when the shutter disk is not stopped, the shaft of the shutter can be moved mechanically, so that the shutter can be released within one second from the state in which the shutter is in use. In addition, although a manual mechanical release method is used in the embodiment, an automatic release method using a solenoid or the like may be used in a shorter time (for example, 10
0m5). Similarly, first the shutter disk 2O
Since it is also possible to rotate the shutter and place the shutter on the optical axis, it is possible to reliably switch from the shirt sash usage state to the usage state in a short time. Therefore, it is possible to quickly respond to large changes in the amount of light, such as from indoors to outdoors or vice versa, or when forced illumination is turned on and off. It is also possible to turn on the shutter function when the illumination is turned on and when the illumination is turned on. Further, a reflecting member 10 having a spectroscopically neutral reflecting surface provided on the surface of the shutter plate 2O with respect to the photometric element 105
Since the reflected light from 6 is made incident, photometry can be performed accurately.

Therefore, proper exposure operation can be performed. This device is small and has a simple structure, so it can be manufactured at low cost and is suitable as a home video camera.

Note that the present invention is not limited to the above embodiment.

For example, in the above embodiment, the slits are formed at two places on the disk, but they may be formed at one place or three or more places depending on the usage conditions. Further, the number of the discs with slits may be one or three or more. However, in the case of only one sheet, it is necessary to provide a minute shielding plate or the like to be slidable so that the slit width can be locally varied. Rough motor 14
In the above embodiment, a so-called direct drive mechanism was used in which the shaft of the shutter plate was also used as the shaft of the motor 14 as a means of transmitting power from the motor 14, but the power was transmitted by a mechanism using a boot, a belt, gears, etc. It's okay.

In this way, the lever plate 13 can rotate only the shutter plate, and the motor 14 can be fixed, which has the advantage of providing excellent operability. Further, in the above embodiment, when the direct photometry method is adopted, the reflected light from the surface of the C0D 80 and the reflected light from the reflection member 106 provided on the surface of the shirt shirt plate 20 are made to enter the photometric element. As shown in the figure, holding frame 1 of CCD80
09 may be provided with a reflecting member 110, and the reflected light from this reflecting member 110 may also be utilized. Furthermore, as the photometric element, a normal photometric element may be used, or a direct photometric element placed outside the light flux necessary for photographing may be used. Further, since the strobe control/photometering circuit 100 is supplied with the video output signal of the previous field from the video signal processing circuit 94, this may be used as the photometering signal. moreover! Of course, the a-image device may be a device other than a video camera.

〔Effect of the invention〕

The present invention provides the above-described m
A rotary shutter mechanism having a shutter plate with slits for exposing the S element is provided so that it can be inserted at any time, and a photometric element is provided between the shutter mechanism and the optical system, and the optical system is connected to the photometric element. The structure is such that the light that enters through the lens is reflected by a reflecting member and then enters the light. Therefore, even if the subject is moving quickly, the image will not be blurred due to the "tailing phenomenon".
In addition, in a device that can obtain clear still images with less blur, the i-image device is capable of releasing the shutter as necessary and metering the light incident on the image sensor to perform appropriate exposure. Can be provided.

[Brief explanation of the drawing]

Figures 1 to 23 show an embodiment in which the present invention is applied to a video camera. Figure 1 is an external perspective view of the video camera, and Figure 2 is a cutaway view of the main part of Figure 1. FIGS. 3 and 4 are plan views showing the structure of the first and second disks with slits, and FIGS. 7 and 8 are plan views of the shutter plate combined with the second disc with slits, and FIGS. 1st
Figure 0 and Figures 11 (a), (b), and (c) are explanatory diagrams of how to set the slit width of the shirt plate, and Figures 12 (a) and (b).
) is an explanatory diagram of the possible exposure time depending on the type of imaging means, and Figures 13 (a) to 1) and 14 (a) to (d) show image quality deterioration when exposure is performed outside the possible exposure time. Figures 15(a) and 15(b) are diagrams showing an example of a batch transfer type solid-state image sensor, and Figure 16 is an explanation of means for increasing the maximum shutter speed that can be used during delight synchronization photography. 17 to 19 are diagrams showing specific examples of the solid-state image sensor used in this device, and FIGS. 20 and 21 are block diagrams showing the configuration of the control system, and FIGS.
3 is a diagram showing a timing chart of the circuits shown in FIGS. 20 and 21, respectively, and FIG. 24 is a front view showing a schematic configuration of an image sensor portion in another embodiment of the present invention. 1... Video camera body, 2... Optical system, 8...
Manual knob, 11... Image pickup element, 12... Rotary shutter mechanism, 13... Lever plate, 20... Shaft plate, 21... First slitted disc, 22... Second Discs with slits, 21a, 21b, 22a, 22b
... Notch, 21c, 21d... Locking piece, 22c,
22d... Projection piece, 33... Pin, 35a, 35b.
...Square hole, 36...Ball, 37...Guide, 41
．． 51... Photoelectric conversion surface, 42.52... Slit opening, 60.70° 80... Solid-state image sensor, 106.1
10... Reflective member. Applicant's agent Patent attorney Jun Tsuboi Figure 1 Figure 2 Figure n Figure 3 'r,,'>41''4 Figure 5 Figure 6 [! N2/'11a Fig. 7 Fig. 8 Fig. 1 Fig. 9 1 1st ON 11 Fig. 0 Fig. 12 Fig. 14 Fig. 15 Fig. 16 Fig. 1

Claims (4)

[Claims] (1) An imaging device main body, an optical system attached to the main body that collects incident light from a subject, an image sensor that photoelectrically converts the image produced by this optical system, and a link from the optical system to the AM element. a rotary shutter mechanism having a shutter plate with a slit that can be inserted into an optical path and exposes the image sensor; a photometric element provided between the rotary shutter mechanism and the optical system; An imaging device comprising: a reflecting member that reflects light incident on a photometric element through the optical system and causes the light to enter the photometric element. (2) The imaging device according to claim (1), wherein the reflecting member has a photometric reflecting surface with a substantially flat spectral reflectance distribution in the wavelength range of the light used. (3) The reflective member is provided on the surface of the light shielding portion of the slit shirt plate.
1) The imaging device described in section 1). (4) The imaging device according to claim (1), wherein the reflecting member is provided on a holding frame of the imaging element.