JPH0698219A - Video camera - Google Patents

Abstract

PURPOSE:To provide a compact video camera which performs the photography by an external trigger with the use of a solid state image pickup element having no electronic shutter function and can surely eliminate the influence of the ambient light for improvement of the picture quality. CONSTITUTION:The photographing is carried out with only an external trigger and with the pulse light emission by means of a solid state image pickup element 4 having no electronic shutter function. An optical image formed by the infrared light given from an object is photographed by the element 4 taking advantage of a fact that the ambient light of the subject includes no infrared component. In this respect, an infrared filter 3 is provided to transmit only the infrared light of the optical image sent from the object together with a light source lamp 9 which emits the infrared light or the light including the infrared component to the object as the illumination light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized video camera using a solid-state image pickup device, and is suitable for application to, for example, an image pickup of a moving object or a rotating body at a fixed position.

[0002]

2. Description of the Related Art Conventionally, a camera head unit having an objective lens and an image pickup device, and a camera control unit having a configuration for driving the image pickup device and a process for processing a video signal from the image pickup device are connected by a camera cord. There is a video camera.

In such a video camera, not only the camera head can be positioned almost independently of the position of the camera control section, but also the camera head section is separated from the camera control section by a small size. It can be made lightweight and can be inserted into a narrow space or a closed space, or can be attached to a support having a small allowable load. Therefore, the video camera in which the camera head is connected not directly to the camera control unit via the camera cord is used not only for industrial endoscopes and medical endoscopes, but also for example, when the camera head is connected to the robot arm. When controlling the operation of the robot with the image attached to the tip and captured by the camera head, or when using the captured image to position the workpiece by installing the camera head near the workpiece. Is also used.

In a video camera used for such an application, it is preferable that the camera head section be small and light in weight. Therefore, the image pickup element provided in the camera head section is a solid-state image pickup element, especially a CCD (charge-junction element). Is the most. As is well known, CCD (two-dimensional CC
D) is roughly classified into a frame transfer method, an interline transfer method, and a line transfer method according to the scanning method. Among them, the CCD according to the line transfer method which does not require the storage unit is the smallest and the camera head can be the smallest.

As described above, in a video camera in which the camera head unit is connected to the camera control unit not directly but through the camera cord, for example, the camera head unit is attached to the tip of the robot arm and the image captured by the camera head unit is taken. It is also used when controlling the operation of the robot by using a camera head part provided near the workpiece and using the captured image for aligning the workpiece.
Therefore, a moving object or a rotating body that is moving at high speed may be imaged, and an object may be imaged while the camera head unit side is moving even if the object is fixed or moves slowly.

As described above, when an image is taken while the subject and the camera head are moving relative to each other, in order to prevent the image quality from being deteriorated due to the movement, the subject is momentarily imaged and is almost equivalent to a still image. It is done to get a clear image. For example, flash photography is performed, and an instantaneous image is captured by a shutter function without controlling illumination.

When an instantaneous image of a subject is taken by the shutter function, a CCD having an electronic shutter function is generally used because the camera head part becomes large in size due to the mechanical shutter mechanism. Many of the frame transfer type and interline transfer type CCDs have an electronic shutter function. In the CCD having the electronic shutter function, when the charges are transferred from the photosensitive section to the storage section, the overflow drain provided for each light-receiving element sweeps out all the electric charges accumulated up to that time to the outside, and Charge is once emptied, and then the charge is stored again in the photosensitive section for the required period (time when the shutter is open).
Transfers charge to the storage section. By performing such an operation, the exposure period (charge accumulation period) can be shortened, and the output image can be clear without blur even when the subject and the camera head are moving or rotating relatively. You can

By using such an electronic shutter function of the CCD, it is possible to construct a video camera having an external trigger function. That is, the above-mentioned charge sweeping, charge re-accumulation, and charge transfer are performed at an arbitrary timing by a trigger signal input from the outside of the video camera, and an almost instantaneous subject image is obtained immediately after the trigger signal is given. A corresponding standard television signal can be output.

In practice, in a system using a video camera as an electronic eye, an image at a fixed position of a moving body or a rotating body is often required, and a position detection signal of the moving body or the rotating body is used as an image pickup trigger. Often

[0010]

However, the above-mentioned line transfer type CCD, which can make the shape of the camera head the smallest, generally does not have an electronic shutter function and can be imaged by an external trigger. Can not. If the line transfer CCD is equipped with an electronic shutter function, the structure becomes complicated because of the overflow drain provided for each light receiving element, and it is difficult to reduce the size.
Furthermore, since an input pin for controlling the overflow drain is required, the number of lead wires that go out of the package increases, which is also undesirable from the viewpoint of miniaturization.

Therefore, it is difficult to mount an external trigger function on a video camera having a line transfer type CCD in order to realize photographing at a fixed position of a moving body or a rotating body, and even if it can be realized, the video camera can be realized. The whole or the camera head part becomes large.

A similar problem occurs in a video camera using a CCD or other solid-state image pickup device which does not have an electronic shutter function and which follows a frame transfer system or an interline transfer system.

The present invention has been made in consideration of the above points, and is a small-sized image pickup apparatus capable of picking up an image of a subject at an arbitrary timing by a trigger signal from the outside using a solid-state image pickup device having no electronic shutter function. It is intended to provide a video camera.

[0014]

In order to solve such a problem, according to the present invention, in a video camera using a solid-state image pickup device having no electronic shutter function, only infrared light of an optical image from a subject is transmitted. An optical filter, an illuminating means for emitting infrared light or light containing infrared light as illuminating light to a subject, and a pulse signal for illuminating the illuminating means at arbitrary timing by a trigger signal given from the outside of the video camera. And an illumination control means for controlling the light source, and capturing an optical image of infrared light from the subject based on a trigger signal from the outside.

Here, the electric charge relating to the optical image received from the solid-state image pickup device is transferred also during the period when the illuminating means waits for light emission, and the accumulated charge in the solid-state image pickup device is emptied during the period when the illuminating means waits for light emission. It is preferable to do so.

Further, it is preferable that the solid-state image pickup device is a charge coupled device according to a line transfer system.

Further, it is preferable that the lighting control means can set the light emission time of the lighting means continuously or stepwise.

Furthermore, it is preferable that the illumination control means controls the emission intensity of the illumination means in correspondence with the emission period.

Further, it is provided with an image intensity detecting means for detecting the intensity of the image signal outputted from the solid-state image pickup device, and the illumination control means controls the light emission intensity of the illuminating means according to the detection output by the image intensity detecting means. Is preferred.

Further, it is preferable that the illumination means is an infrared light emitting diode or an infrared laser diode.

Furthermore, it is preferable that the camera head section having the solid-state image pickup device is connected to the camera control section via a camera cord.

In the video camera having the camera cord, it is preferable that the illuminating means is provided on the connector for connecting the camera cord to the camera control section, and the light guide for guiding the illuminating light from the illuminating means is provided on the camera cord.

Further, in the video camera having the camera cord, it is preferable that the illumination means is provided in the camera head portion.

Further, in a video camera having a camera code, a lighting means is provided in the camera control section,
It is preferable to provide a light guide that guides the illumination light from the illumination means. Such a light guide is preferably provided in the camera cord.

Furthermore, it is a preferable aspect that the lighting means is provided separately from the camera control section and the camera head section, and the electric signal to the lighting means is supplied from the camera control section or the camera head section.

[0026]

Since the solid-state image pickup device having no electronic shutter function is small in size, it is used in a video camera which is required to be downsized. In a video camera having such a solid-state image sensor having no electronic shutter function, if it is attempted to capture an image only when an external trigger signal is given, it is conceivable that the image is captured by pulsed light emission similar to stroboscopic image capturing. However, even if an image is picked up by pulsed light emission, it will be adversely affected by ambient light. That is, there is a problem in that an image is captured by both pulsed light and ambient light during the light emission period, and since ambient light exists even outside the light emission period, an optical image is accumulated in the photosensitive section of the solid-state image sensor before the pulse light emission. There is a problem that it has been done.

The present invention was made by paying attention to the fact that ambient light of an object has almost no infrared component in a factory or a laboratory in which fluorescent lamps or discharge lamps are used as indoor lights. The subject is pulse-illuminated with light including external light or infrared light, and an optical image of infrared light is reflected from the reflected light to capture the effect of ambient light around the subject from the image captured by pulsed light emission based on an external trigger. Can be reliably removed, and it is possible to respond to such things as imaging a rotating or moving subject at a fixed position.

That is, an optical filter that transmits only infrared light of an optical image from a subject, and an illumination unit that emits infrared light or light containing infrared light as illumination light to the subject,
The video camera is provided with an illumination control means for emitting pulsed light from the illumination means at an arbitrary timing by a trigger signal given from the outside, and an optical image is captured by infrared light from a subject based on the trigger signal from the outside. I decided.

Here, in order to clear the picked-up image at the time of pulse emission by removing the influence of the image by infrared light other than the light-emission period from the picked-up image at the time of pulsed light emission, the illumination means is also in the light emission standby state. It is preferable that electric charges relating to the optical image received from the solid-state imaging device are transferred so that the accumulated charges in the solid-state imaging device are emptied while the illumination unit is in the standby state for light emission.

Further, it is preferable that the solid-state image pickup device is a charge-coupled device according to the line transfer method because the whole video camera or the camera head can be made smaller than the other solid-state image pickup device.

Further, it is preferable that the illumination control means can set the light emission time of the illumination means continuously or stepwise so that the image can be captured in an appropriate state according to the imaging environment.

At this time, it is preferable that the illumination control unit realizes a sufficient amount of received light even when the emission period is short by controlling the emission intensity of the illumination unit in correspondence with the emission period. By controlling in this manner, it is possible to prevent the light amount from becoming excessive and shortening the life of the illuminating means and increasing the power consumption.

Further, in order to obtain a desired amount of received light, an image intensity detecting means for detecting the intensity of the image signal output from the solid-state image pickup device is provided, and the illumination control means detects the emission intensity of the illuminating means by the image intensity. It is preferable to construct a feedback system that controls according to the detection output by the means.

Further, it is preferable to use an infrared light emitting diode or an infrared laser diode as the illuminating means so that the structure relating to the illumination is small, inexpensive and has a long life. Note that the infrared light emitting diode and the infrared laser diode are lighting means whose light emission time is easily controlled.

Furthermore, when there is not enough space for installing a video camera near the subject, a video camera in which a camera head section having a solid-state image sensor is connected to a camera control section via a camera cord is used. preferable.

In a video camera having a camera code, when it is necessary to downsize the camera control section,
It is preferable that the illumination means is provided on the connector for connecting the camera cord to the camera control section, and the light guide for guiding the illumination light from the illumination means is provided on the camera cord.

In the case of a video camera having a camera cord, it is preferable to provide the illuminating means on the camera head when the camera controller needs to be downsized and the flexibility of the camera cord is required to be improved.

Further, in the video camera having the camera code, considering the maintenance of the illumination means,
It is preferable that the illumination means is provided in the camera control section and a light guide for guiding the illumination light from the illumination means is provided.
It is preferable that such a light guide is provided in the camera cord because there are few cords related to routing.

Furthermore, it is preferable that the illumination means is provided separately from the camera control section and the camera head section, and the electric signal to the illumination means is supplied from the camera control section or the camera head section, since the subject can be appropriately illuminated. This is one aspect.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) First Embodiment Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. Here, FIG. 1 shows the overall configuration of the first embodiment.

In FIG. 1, the video camera of the first embodiment is roughly composed of a camera head section 1, a camera control section 8 and a camera cord 7. The camera head unit 1 is provided at the tip of the camera cord 7. The base end of the camera cord 7 is a connector 6, and the connector 6 connects the camera cord 7 to the camera control unit 8.

The camera control section 8 includes a light source lamp 9, a video signal amplification circuit 10, a timing generation circuit 11,
CCD drive circuit 12, lamp drive circuit 13, television signal output terminal 14, external trigger input terminal 15
And a pulse width setting circuit 16.

In this video camera, an external trigger signal TR for instructing the start of shooting is applied to the external trigger input terminal 15 from an external device, and the external trigger signal TR input to this input terminal 15 is It is given to the timing generation circuit 11. For example, in a system that acquires an image of a fixed position of a moving body or a rotating body and uses the image, an external trigger signal TR is given to the video camera of this embodiment from the position detecting device of the moving body or the rotating body.

The timing generation circuit 11 has a CC which will be described later.
A charge transfer timing signal C1 for D4 and a lamp timing signal C2 for the light source lamp 9 are generated, and the charge transfer timing signal C1 is given to the CCD drive circuit 12 and the lamp timing signal C2 is given to the lamp drive circuit 13.

The pulse width setting circuit 16 is a circuit for setting the pulse width (photosensitive time) of the lamp timing signal C2 corresponding to the shutter speed of a normal camera, and is set by the operator in accordance with the image pickup environment. To do. The pulse width setting circuit 16 may have a volume or the like to continuously set the pulse width, or may have a multi-contact rotary switch or the like to set the pulse width stepwise. It may be.

As described later, the timing generating circuit 11 generates a lamp timing signal C2 for instructing light emission for a period set by the pulse width setting circuit 16 from the rising edge of the trigger signal TR, for example.
As will be described later, the timing generation circuit 11 repeatedly generates the charge transfer timing signal (clock signal) C1 within a predetermined period when the trigger signal TR is not applied, and thereafter interrupts the generation for the predetermined period, and repeats this. Occurrence and interruption are repeated periodically. The timing generation circuit 11
When the trigger signal TR is given, the generation of the charge transfer timing signal C1 is stopped during the generation period of the ramp timing signal C2, and the charge transfer timing signal C1 is generated after the ramp timing signal C2 is returned from the generation to the non-generation. Start over.

When the lamp timing signal C2 is given from the timing generation circuit 11, the lamp drive circuit 13 amplifies it and gives it to the light source lamp 9 as a lamp drive signal D2. The light source lamp 9 is composed of, for example, an infrared light emitting diode or an infrared laser diode, emits light when a lamp drive signal D2 is given from the lamp drive circuit 13, and emits infrared light or light containing infrared light. To do. The camera cord 7 includes an optical fiber light guide 5 penetrating from the base end to the tip. The light source lamp 9 is provided in the vicinity of the end face of the light guide 5 on the base end side, and the light beam emitted from the light source lamp 9 is directly incident on the light guide 5 and passes through the light guide 5 to emit light. The light is emitted from the end face of the guide 5 (end face of the camera head unit 1). Note that the camera cord 7 is actually flexible and has an outer diameter of 4 to 5
It is about mm.

The camera head unit 1 is directed to a subject (not shown), and the light beam emitted from the end face of the light guide 5 on the front end side is applied to the subject. Camera head 1
Is provided with an objective lens 2, an infrared transmission filter 3 and a CCD 4 in this order from the subject side. The reflected light from the subject is condensed by the objective lens 2, and a subject image is formed on the photosensitive portion of the CCD 4. At this time, since the light is transmitted through the infrared transmission filter 3, a subject image by infrared light is formed on the photosensitive portion of the CCD 4. Actually, the outer diameter of the camera head unit 1 is about 7 to 9 mm when the oval CCD 4 having a 5.5 mm circular upper and lower parts is cut out.

Generally, a fluorescent lamp or a discharge lamp is used as an illuminating means in a room where a subject is present. However, these indoor lights do not emit a light component in the infrared region, and therefore an image is formed on the photosensitive portion of the CCD 4. The formed subject image is only an image of light (infrared light) emitted from the light source lamp 9 reflected from the subject.

In the case of the first embodiment, the camera head unit 1
In consideration of downsizing and weight reduction, a line transfer type CCD 4 is applied. That is, the CCD 4 does not have an electronic shutter function, and therefore, as described above, image pickup according to the external trigger signal TR is performed by pulsed light emission. The timing generation circuit 11 described above generates the ramp timing signal C2 with a predetermined pulse width, and then charges the charge transfer timing signal (clock signal).
C1 is output to the CCD drive circuit 12, and the CCD drive circuit 12 amplifies it and gives it to the CCD 4 as a CCD drive signal D1 via a signal line in the camera code 7. As a result, the CCD 4 sequentially transfers the accumulated charges obtained by photoelectrically converting the subject image in the photosensitive section, and supplies the video signal S obtained by the transfer processing to the amplifier circuit 10 of the camera control section 8 via the signal line. The amplifier circuit 10
Output terminal 1 that amplifies video signal S and uses amplified signal V0 as a television signal (but does not include a sync signal component)
4 to the next stage device.

Next, the operation of the video camera having the above configuration will be described with reference to FIG. Note that FIG. 2 is a timing chart of each part of the video camera having the above configuration.

When the trigger signal TR shown in FIG. 2 (A) is applied from the external trigger input terminal 15, the timing generating circuit 11 generates the charge transfer timing signal C1 at the rising edge thereof as shown in FIG. 2 (C). Interrupted, also Figure 2
As shown in (B), the ramp timing signal C2 starts to be generated. The generation interruption period of the charge transfer timing signal C1 and the generation period of the ramp timing signal C2 are set periods by the pulse width setting circuit 16. The lamp timing signal C2 is amplified by the lamp drive circuit 13 and given to the light source lamp 9 as the drive signal D2, whereby the light source lamp 9 emits and emits light. The emitted light (infrared light) passes through the light guide 5 and is applied to the subject, and the reflected light from the subject is imaged on the CCD 4 through the objective lens 2 and the infrared transmission filter 3 sequentially.

FIG. 3 shows the relative spectral characteristics of various optical elements provided in the video camera of the first embodiment. The light source lamp 9 has a relative spectral emissivity characteristic curve 21.
As shown in (1), it emits infrared light in the wavelength range of 780 to 900 nm. The infrared transmission filter 3 (for example, product name IR80 manufactured by Hoya Co., Ltd.) has a relative spectral transmittance characteristic 22 that widely covers the infrared region including the wavelength range of the irradiation light of the light source lamp 9, and is visible. The light area is not transmitted. Therefore, when the ambient light does not include the infrared region due to the indoor fluorescent lamp or the discharge lamp, the infrared light transmitted through the infrared transmission filter 3 is the infrared light emitted from the light source lamp 9 and reflected from the subject. Only light. C
As shown by the relative spectral sensitivity characteristic curve 20, the CD 4 has sensitivity not only in the visible light region but also in a part of the infrared region, and in the infrared light region emitted from the light source lamp 9 and reflected from the subject. On the other hand, it has a relative spectral sensitivity of 0.5 or more. That is, only the subject image by infrared light is captured.

As shown in FIG. 2C, the timing generating circuit 11 transfers an electric charge for each video period of the horizontal scanning period after an infrared image is formed on the CCD 4 and photoelectric conversion is performed. A timing signal (clock signal) C1 is output.
The charge transfer timing signal C1 is amplified by the CCD drive circuit 12 and supplied to the CCD 4, which causes the CCD 4 to transfer the charge accumulated in the photosensitive section to a one-dimensional signal train, as shown in FIG. That is, the video signal S is output. The video signal S is inverted and amplified by the amplifier circuit 10, smoothed, and output from the output terminal 14 as the television signal V0 shown in FIG.

The charge transfer timing signal (clock signal group) C1 for transferring the accumulated charge for one image is shown in FIG. 2 even when the trigger signal TR is not applied.
It is generated periodically as shown in (C). However, such a charge transfer timing signal (clock signal group) C1
Immediately before the generation period T of, the ramp timing signal C2 is not generated as shown in FIG. Therefore,
The image relating to the accumulated charges transferred in this period T is an image of the infrared component of the reflected light from the subject of the ambient light. As described above, when the ambient light is from an indoor fluorescent lamp or a discharge lamp, the infrared region is not included, so that the video signal S is almost sent from the CCD 4 as shown in FIG. Absent. Even if there is a slight infrared region in the ambient light, the accumulated charges are swept out by such a transfer operation, so that the CCD 4 is always in the empty state when the trigger signal TR is on standby. Therefore, the image (accumulated charge) captured by driving the light source lamp 9 based on the trigger signal TR is not affected by the accumulated charge before driving the light source lamp 9.

Therefore, according to the first embodiment, even if the CCD 4 of the line transfer system is applied as the image pickup device in consideration of the reduction in size and weight of the camera head unit 1, the infrared image can be obtained by the pulse emission. Therefore, the subject image can be obtained at an arbitrary timing by the external trigger.

Here, since the transfer operation is executed even when there is no pulse emission and the unnecessary accumulated charges of the CCD 4 are discharged, the image quality of the picked-up image by pulse emission can be improved. Therefore, it is possible to realize a video camera suitable for capturing an image of a moving body or a rotating body at a fixed position.

As a method of obtaining such an effect, it is considered that ultraviolet light is pulsed to form an ultraviolet image, but this is not practical. That is, the CCD is shown in FIG.
This is because the sensitivity to ultraviolet light is poor and the light source lamp that emits ultraviolet light and the optical filter that transmits it are expensive as shown in FIG.

Further, according to the first embodiment described above, since the infrared light emitting diode or the infrared laser diode is applied as the light source lamp 9, compared with the case where the discharge lamp or the fluorescent lamp is applied, the camera. The configuration of the control unit 8 can be made small. That is, not only is the light source lamp 9 itself reduced in size, but an optical system for causing the light emitted from the light source lamp 9 to enter the light guide 5 can be eliminated, so that the size can be reduced. When an infrared light emitting diode or an infrared laser diode is applied as the light source lamp 9, the size of the camera control unit 8 is about 1/4 to 1/5 as compared with the case where a discharge lamp or a fluorescent lamp is applied. I was able to

Furthermore, since an infrared light emitting diode or an infrared laser diode is applied as the light source lamp 9,
The power consumption (heat dissipation amount) in the camera control section 8 can be reduced, the life can be extended, and the cost can be reduced.

Furthermore, since the infrared light emitting diode or the infrared laser diode is applied as the light source lamp 9, it is possible to appropriately control the light amount and the light emitting time to be predetermined. That is, the xenon lamp used in many conventional video cameras has a narrow relative controllable range of light amount and emission time, but the infrared light emitting diode or infrared laser diode has a wide controllable range. As a result, it becomes possible to execute appropriate control of the amount of light and the light emission time according to the imaging target and the imaging environment.

Incidentally, the infrared light emitting diode or the infrared laser diode has a smaller absolute radiant light quantity than the incandescent lamp or the discharge lamp, but in the case of this embodiment,
Since imaging is performed with infrared light that does not exist in ambient light, it is not necessary to consider the light intensity level of ambient light, and imaging can be sufficiently performed with the amount of light emitted by these diodes.

(B) Second Embodiment FIG. 4 shows the configuration of the second embodiment of the present invention.
The same or corresponding parts as in FIG. 1 are designated by the same reference numerals.

In the second embodiment, as shown in FIG. 4, a light source lamp 9 composed of an infrared light emitting diode or an infrared laser diode is built in the connector 6 portion of the camera cord 7 to the camera control section 8. Different from the first embodiment. Since the light source lamp 9 is an infrared light emitting diode or an infrared laser diode, it can be provided at such a position.

According to the second embodiment as well, the same effects as those of the first embodiment can be obtained, and further the following effects can be obtained. That is, in the case of the first embodiment,
Since there are two types of connection between the camera cord 7 and the camera control unit 8, that is, electrical connection and optical connection, the connection structure is complicated, but in the case of the second embodiment, electrical connection is made. Since only the connection is made, the connection structure can be simplified. However, as compared with the first embodiment, the size of the connector 6 is increased, and when one camera control unit 8 is commonly used by a plurality of camera cords 7, the number of light source lamps 9 required is increased.

(C) Third Embodiment FIG. 5 shows a third embodiment of the present invention, in which the same or corresponding parts as in FIG. 1 are designated by the same reference numerals.

The third embodiment differs from the first embodiment in that the light source lamp 9 is provided on the end face of the camera head 1 as shown in FIG. 5, and therefore the lamp drive is used instead of the light guide 5. A signal line for the signal D2 is provided in the camera cord 7. Also in the third embodiment, since the light source lamp 9 is an infrared light emitting diode or an infrared laser diode, it can be provided at such a position.

Also according to the third embodiment, the same effects as those of the first embodiment can be obtained, and the following effects can be further obtained. That is, since the light guide 5 is not provided, the outer diameter of the camera cord 7 can be further reduced, and the flexibility of the camera cord 7 can be increased to facilitate the wiring. Further, since there is no light guide 5 that is more easily damaged than the electric signal line, the reliability of the camera code 7 can be improved. Further, in the first and second embodiments, when the camera cord 7 is long, the transmission loss due to the light guide 5 becomes a problem, but in this embodiment, such a problem does not occur. However, as compared with the first embodiment, when the required light amount for illuminating the subject is large, the light source lamp 9 having a high light amount is applied, and therefore the camera head unit 1 becomes large.

(D) Fourth Embodiment FIG. 6 shows a fourth embodiment of the present invention, in which the same or corresponding parts as in FIG. 1 are designated by the same reference numerals.

In the fourth embodiment, as shown in FIG. 6, an illumination means mounting portion 17 having a light source lamp 9 is provided separately from the camera control portion 8 and the camera head portion 1, and the camera control portion 8 and the illumination means are provided. The mounting portion 17 is connected by a signal line 18.

According to the fourth embodiment as well, the same effects as those of the first embodiment can be obtained, and further the following effects can be obtained. That is, the light source lamp 9 can be installed closer to the subject, and the subject can be sufficiently illuminated with a small amount of light. In addition, as compared with the first embodiment, the number of cords to be laid out (signal lines and camera cords) is increased.

As a modification of the fourth embodiment, it is conceivable that the lamp drive signal D2 is applied to the illumination means mounting section 17 via the camera head section 1.

(E) Fifth Embodiment FIG. 7 shows a fifth embodiment of the present invention, in which the same or corresponding parts as in FIG. 1 are designated by the same reference numerals. The video camera of the fifth embodiment is one in which the present invention is applied to a video camera having no camera code. As described above, since the camera head unit 1 and the camera control unit 8 can both be miniaturized, the video camera directly connected to them can also be miniaturized and easily attached to the support.

(F) Sixth Embodiment FIG. 8 shows the internal structure of the camera control section 8 in the sixth embodiment of the present invention. The same or corresponding parts as in FIG. 1 are designated by the same reference numerals. Is shown. The configurations of the camera head unit 1 and the camera cord 7 in the sixth embodiment are the same as those in the first embodiment.

The pulse width setting circuit 16 of the sixth embodiment
Supplies the information on the set pulse width to the timing generation circuit 11, and also supplies the drive current setting signal DI according to the pulse width (that is, according to the light emission time) to the lamp drive circuit 13. Drive current setting signal D
I indicates a small drive current when the set pulse width is large, and a large drive current when the set pulse width is small (however,
Not limited to a linear relationship). The lamp drive circuit 13 supplies the lamp drive signal D2 having the drive current value set during the period in which the lamp timing signal C2 is instructing the light emission to the light source lamp 9 for pulsed light emission. Therefore, it can be said that the emission intensity is controlled according to the emission time.

If the drive current value is fixed regardless of the pulse emission period, the following problems may occur. When the drive current value is set to a small value, if the pulse emission period is short, the amount of light received by the CCD 4 is reduced, and the television signal V0 may be dark as a whole and the image quality may be degraded. On the other hand, in the case where the drive current value is set to be large, if the pulse emission period is long, there is a possibility that the heat generation from the light source lamp 9 increases and the life of the light source lamp 9 is shortened. There is.

According to the sixth embodiment, not only the same effect as in the first embodiment cannot be obtained, but also such an inconvenience can be effectively avoided. The configuration of the camera control unit 8 is more complicated than that of the first embodiment.

(G) Seventh Embodiment FIG. 9 shows the internal structure of the camera control section 8 in the seventh embodiment of the present invention. The same or corresponding parts as in FIG. Is shown. The configurations of the camera head unit 1 and the camera cord 7 in the seventh embodiment are the same as those in the first embodiment.

In the seventh embodiment, the light emission intensity is controlled in accordance with the light emission time (pulse width) as in the sixth embodiment, and further, depending on whether or not the amount of light received by the CCD 4 is sufficient for image quality. Also controls the emission intensity.

The pulse width setting circuit 16 supplies the information of the set pulse width to the timing generation circuit 11 and controls the drive current setting signal DI according to the pulse width (that is, according to the light emission time). It is given to the circuit 19. In the seventh embodiment as well, the drive current setting signal DI indicates a small drive current when the set pulse width is large, and indicates a large drive current when the set pulse width is small.

The video brightness detecting circuit 18 carries out the brightness information of the television signal V0 of the image obtained by the pulse emission (for example, the brightness average value, the peak value, the average value and the peak value in the one frame period, and the weighted combination). Calculated value),
Next, a difference between the reference luminance information set in advance by a volume or the like and the obtained luminance information is obtained, and the difference is given to the drive current control circuit 19 as a luminance error signal YE.
Here, the reference luminance information is set to a value at which it can be determined that the amount of light received by the CCD 4 is sufficient for image quality.

The drive current control circuit 19 receives the drive current setting signal DI supplied from the pulse width setting circuit 16.
Is corrected to a direction in which the brightness error signal YE becomes 0 according to the brightness error signal YE, and this is given to the lamp drive circuit 13 as a drive current control signal DC. The current value of the drive current setting signal DI may be set as the upper limit.

The lamp drive circuit 13 gives a pulse drive to the light source lamp 9 by supplying the lamp drive signal D2 having the drive current value instructed by the drive current control signal DC during the period in which the lamp timing signal C2 instructs the light emission. .

Therefore, according to the seventh embodiment, pulsed light emission can be performed with an appropriate light emission intensity that does not cause image quality deterioration and does not cause various problems with the light source lamp 9. Further, in the sixth embodiment, for example, the characteristics such as the reflectance of the subject and the distance between the subject and the camera could not be reflected in the emission intensity, but according to the seventh embodiment, it is possible to obtain it by imaging. Since the luminance information of the obtained television signal V0 is reflected in the emission intensity, such characteristics can also be reflected in the emission intensity, and the image of the subject can always be obtained under the optimum imaging conditions.

Of course, the same effect as that of the first embodiment can be obtained. The configuration of the camera control unit 8 is more complicated than that of the first embodiment.

(H) Other Embodiments In the above embodiment, the infrared transmission filter 3 is located between the objective lens 2 and the CCD 4, but the infrared transmission filter 3 is placed in front of the objective lens 2 ( It may be provided on the subject side).

In the above embodiment, the camera head unit 1
Although the objective lens 2 and the like are exposed to the outside, a transparent protective glass for protecting the light source lamp 9, the objective lens 2 and the like may be provided on the front surface of the camera head 1 on the object side.

In the above embodiments, the solid-state image pickup device is a CCD that complies with the line transfer system, but a CCD that does not have an electronic shutter function and complies with the frame transfer system or the interline transfer system may be applied. Further, it goes without saying that a solid-state image sensor other than the CCD, which is also sensitive to the infrared region, may be applied.

As in each of the above embodiments, the light source lamp 9 is preferably an infrared light emitting diode or an infrared laser diode, but a discharge lamp or an incandescent lamp that emits a light ray containing an infrared component is applied as a light source lamp. You may.

[0090]

As described above, according to the present invention, an optical filter that transmits only infrared light of an optical image from a subject and infrared light or light containing infrared light as illumination light to the subject. And an illumination control means for causing the illumination means to emit a pulse light at an arbitrary timing by a trigger signal given from the outside of the video camera, and an infrared ray from the subject is emitted based on the trigger signal from the outside. Since the optical image is picked up by the light, only the optical image during the light emission can be picked up by pulsed light emission based on the external trigger signal, and the influence of ambient light can be surely excluded. As a result, it is possible to realize a video camera that can easily cope with imaging of a moving or rotating subject at a fixed position.

[Brief description of drawings]

FIG. 1 is a block diagram showing a video camera of a first embodiment.

FIG. 2 is a timing chart of each part of the first embodiment.

FIG. 3 is a characteristic curve diagram showing relative spectral characteristics of various optical elements of the first example.

FIG. 4 is a block diagram showing a video camera of a second embodiment.

FIG. 5 is a block diagram showing a video camera of a third embodiment.

FIG. 6 is a block diagram showing a video camera of a fourth embodiment.

FIG. 7 is a block diagram showing a video camera of a fifth embodiment.

FIG. 8 is a block diagram showing a video camera of a sixth embodiment.

FIG. 9 is a block diagram showing a video camera of a seventh embodiment.

[Explanation of symbols]

1 ... Camera head section, 3 ... Infrared transmission filter, 4 ... Line transfer type CCD (charge coupled device), 5 ... Light guide, 6 ... Connector, 7 ... Camera code, 8 ... Camera control section, 9 ... Light source lamp (Infrared light emitting diode or infrared laser diode), 11 ... Timing generation circuit,
12 ... CCD drive circuit, 13 ... Lamp drive circuit, 15 ... External trigger input terminal, 16 ... Pulse width setting circuit.

Claims (13)

[Claims] 1. A video camera using a solid-state image sensor having no electronic shutter function, wherein an optical filter that transmits only infrared light of an optical image from a subject and infrared light or infrared light as illumination light to the subject. An illumination unit that emits light containing light and an illumination control unit that causes the illumination unit to pulse-light at an arbitrary timing by a trigger signal given from the outside of the video camera are provided, and based on the trigger signal from the outside. A video camera characterized by capturing an optical image of infrared light from a subject. 2. The electric charge relating to the optical image received from the solid-state imaging device is transferred during the period when the illuminating means is waiting for light emission, and the accumulated charge of the solid-state imaging device during the period when the illuminating means is waiting for light emission. The video camera according to claim 1, wherein the video camera is emptied. 3. The video camera according to claim 1, wherein the solid-state image sensor is a line transfer type charge coupled device. 4. The video camera according to claim 1, wherein the lighting control means can set the light emission time of the lighting means continuously or stepwise. 5. The video camera according to claim 4, wherein the illumination control means controls the light emission intensity of the illumination means in correspondence with the light emission period. 6. An image intensity detecting means for detecting an intensity of an image signal output from the solid-state image pickup device, wherein the illumination control means determines an emission intensity of the illuminating means according to a detection output by the image intensity detecting means. 6. The video camera according to claim 1, wherein the video camera is controlled by the following. 7. The video camera according to claim 1, wherein the lighting means is an infrared light emitting diode or an infrared laser diode. 8. The video camera according to claim 1, wherein the camera head unit having the solid-state image pickup device is connected to the camera control unit via a camera cord. 9. The illumination means is provided in a connector for connecting the camera cord to the camera control section,
9. The video camera according to claim 8, wherein the camera cord is provided with a light guide for guiding the illumination light from the illumination means. 10. The video camera according to claim 8, wherein the lighting means is provided in the camera head portion. 11. The video camera according to claim 8, wherein the illuminating means is provided in the camera control section, and a light guide for guiding illumination light from the illuminating means is provided. 12. The video camera according to claim 11, wherein the light guide is provided in the camera cord. 13. The illumination means is provided separately from the camera control section and the camera head section, and an electric signal to the illumination means is supplied from the camera control section or the camera head section. Item 8
Video camera described in.