JP2003158650A - Image pickup device and collision recording system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a function of an image pickup device photographing an image in a plurality of directions at the same time by using a plurality of optical systems to guide the light to other areas of one imaging element. SOLUTION: A polarization element for transmitting only a particular polarized light component is placed at a position on an optical path of each optical system close to the imaging element and a position apart from the imaging element to differentiate the polarized component transmitted by each optical system, adjacent polarization elements close to the imaging element are joined to guide the light from any optical system to all pixels while preventing the overlapped light between different optical systems. The areas of each optical system guiding the light are arranged in a short side direction of the rectangular imaging element to keep the width of each area larger and the optical axis of each optical system is biased toward the center of the entire imaging element from the center of each area to reduce the space occupied by the entire optical system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus for simultaneously picking up images in different directions by one image pickup element, and a collision recording system for recording images at the time of a vehicle collision.

[0002]

2. Description of the Related Art In recent years, an automobile has been equipped with an image pickup device and a display device to photograph and display an image in a direction which is difficult for a driver to see, such as an image in a left-right direction at an intersection with poor visibility and a rear image when retreating. Is being done. Further, an automobile is equipped with an image pickup device and a recording device, and images before and after a collision accident are recorded to help clarify the cause of the accident.

Since it is not necessary to provide an image of high quality in an image pickup device provided in an automobile, even if there are some aberrations, it does not cause any problem and a simple image pickup optical system can be used. On the other hand, even in an image pickup device provided in an automobile, the resolution of an image to be provided needs to be higher than a certain level, and an image pickup element and a circuit for processing its output signal have a performance equivalent to that of a normal digital camera or the like. Is required. Therefore, the cost of the image pickup device and the signal processing circuit is higher than that of the image pickup optical system.

When taking an image in the left-right direction at an intersection, an image pickup device is often arranged on each of the left and right sides of the front part of the automobile. When taking images before and after a collision accident, the imaging devices are often arranged at the front and the rear of the automobile, respectively. However, in such an arrangement, it is difficult to reduce the cost because each image pickup device requires an image pickup optical system, an image pickup element, and a signal processing circuit.

Therefore, two image pickup optical systems and one image pickup element are provided, and light from one image pickup optical system is guided to a half area of the light receiving surface of the image pickup element and light from the other image pickup optical system is received. There is proposed an image pickup device which is adapted to lead to the other half of the area. In the image pickup apparatus having this configuration, in order to prevent light from each of the image pickup optical systems from being incident on the other area of the light receiving surface of the image pickup element that is not the area to which the image pickup element should enter, the image pickup elements of the image pickup elements are overlapped. A light shielding wall perpendicular to the light receiving surface is arranged immediately in front of the light receiving surface. The two image pickup optical systems are set so as to guide lights from opposite directions to the image pickup element, and the image pickup apparatus having this configuration has the left and right sides of the front portion of the vehicle when taking images in the left and right directions at intersections. It is placed in the center, or in the left-right center of the upper part of the passenger compartment when shooting images before and after a collision accident.

[0006]

In the above-mentioned image pickup apparatus in which one image pickup element is commonly used for taking images in two directions, the number of pixels available for taking each image is reduced to about half,
The shooting range of each image is also halved. This is unavoidable, but since the light blocking wall is placed immediately in front of the image sensor to regulate the range of light incident on the image sensor, use only the number corresponding to the thickness of the light blocking wall. The number of pixels that can be obtained is further reduced. That is, the light from any of the image pickup optical systems does not enter the pixel at the position facing the end surface of the light shielding wall, and these pixels cannot contribute to the shooting of any image.

If the light shielding wall is separated from the image pickup element and the distance between them is set appropriately, light from any one of the image pickup optical systems can be made incident on the pixel at a position facing the end face of the light shielding wall. All pixels can be used for photographing while preventing light from overlapping on the light receiving surface of the image sensor. However, for that purpose, in consideration of not only the thickness of the light shielding wall but also the photographing angle of view, the separation distance between the light shielding wall and the image sensor must be designed for each size of the image sensor and the focal length of the imaging optical system. However, versatility is significantly reduced. Also,
A step of adjusting the distance is also required in manufacturing, which leads to a decrease in manufacturing efficiency and an increase in cost.

When the image pickup device is arranged inside the vehicle, it is desirable that the image pickup device be as small as possible. Although the image pickup apparatus is downsized by using only one image pickup element, it is important to set the positional relationship between the two image pickup optical systems with respect to the image pickup elements in order to further reduce the size.

Further, when the image pickup device is arranged in the passenger compartment,
The upper part of the image to be captured includes the ceiling, and the lower part includes the seats, etc., and the meaningful part is the upper and lower central parts. Even when the imaging device is placed outside the passenger compartment, the sky and ground occupy the upper and lower parts of the captured image,
After all, the meaningful part is the upper and lower center. If this is not taken into consideration when the shooting range of one image is halved, the usefulness of the obtained image is greatly reduced.

Furthermore, in the case of capturing and recording images before and after a collision accident, the image in the direction in which the collision occurs is important after the collision, and the image in the direction unrelated to the collision is not particularly necessary. Therefore, after the collision, it is important to process and record only the output signal of all the pixels of the image sensor that are involved in capturing the image in the direction in which the collision occurs, in terms of processing speed and effective use of the recording medium. Is preferred. For that purpose, it is necessary to set the region on which the light from each imaging optical system enters in consideration of the signal output method of the imaging device.

These points have not been taken into consideration in the conventional image pickup apparatus. The present invention has been made in view of the above circumstances, and is an imaging device that simultaneously captures images in a plurality of directions with a single imaging element, and effectively uses pixels to provide a compact and useful image. The objective is to realize what can be efficiently provided. It is another object of the present invention to provide an efficient collision recording system that captures and records images before and after a vehicle collision.

[0012]

In order to achieve the above object, according to the present invention, a plurality of optical systems and one image pickup device are provided, and light from different directions is directed to different regions of the image pickup device by the plurality of optical systems. An image pickup apparatus for guiding and forming an image has a first polarization element in which each optical system is separated from the image pickup element and a second polarization element in proximity to the image pickup element, and the first polarization element in each optical system is different from the other. Deviating from the optical path of the optical system, the second polarization element of each optical system transmits the polarization component from the first polarization element of the optical system, and then the first polarization element of the other optical system. The polarized component of is blocked.

In this image pickup apparatus, each of the plurality of optical systems has a first polarizing element and a second polarizing element, and each optical system uses the first polarizing element to render only a predetermined polarization component. It is guided to the second polarizing element, and the polarized component is transmitted by the second polarizing element to be guided to the image pickup element. Since the second polarization element of each optical system blocks the polarization component from the first polarization element of the other optical system, the light from the other optical system is incident on the area of the image pickup element to which each optical system guides the light. There is no overlap, and no overlap occurs in the captured images. Further, since the first polarizing element of each optical system is out of the optical path of the other optical system, a part of the image will not be lost. It is also possible to bring the edges of the second polarizing elements adjacent to each other into contact with each other, whereby all the pixels of the image pickup element belong to one of the regions, and all the pixels can be used for photographing. . It is also possible to integrate a plurality of second polarizing elements.

According to the present invention, the image pickup apparatus having a plurality of optical systems and one image pickup device, and the light from different directions is guided to different regions of the image pickup device by the plurality of optical systems to form an image is at least one optical system. It is assumed that the optical axis of the system is eccentric from the center of the area of the image pickup device through which the optical system guides light, toward the center of the image pickup device.

When the optical axis of the optical system passes through the center of the area of the image pickup element through which the optical system guides light, the distance between the optical axes of the adjacent optical systems is half the sum of the widths of the adjacent areas of the image pickup element. Set to. However, in this image pickup apparatus, since the optical axes of one or more optical systems are decentered in the central direction of the image pickup element, the distance between the optical axes becomes shorter and the overall size is reduced.

According to the present invention, an image pickup device having a plurality of optical systems and a single image pickup device, wherein the plurality of optical systems guide light from different directions to different regions of the image pickup device to form an image, has a rectangular image pickup device. It is assumed that the regions of the image pickup device where the optical systems guide the light are arranged in the direction along the short side of the image pickup device.

In this image pickup device, the regions of the image pickup device that receive light from the optical system are arranged in the short side direction of the rectangular image pickup device, and each region has a strip shape that is long in the long side direction of the image pickup device. Therefore, it is possible to photograph a range that is wide in one direction and narrow in a direction orthogonal to this.

According to the present invention, the image pickup device is provided with a plurality of optical systems and one image pickup device, and the image pickup device has a predetermined image pickup device for guiding light from different directions to different regions of the image pickup device to form an image. It is assumed that the regions of the image pickup device that output a signal for each column of pixels arranged in the direction and in which each optical system guides light are arranged in a direction perpendicular to the column of pixels of the image pickup device.

In this image pickup device, the image pickup element outputs a signal for each pixel column, and the regions of the image pickup element that receive light from the optical system are arranged in a direction perpendicular to the pixel column of the image pickup element. , The output signals of all the pixels included in the same column are constituent elements of the same image, and are not constituent elements of two or more images. Therefore, it is possible to obtain one entire image by processing only the output signals of the pixels belonging to one area, and when unnecessary, the processing of the output signals of the pixels belonging to the other area can be omitted. This improves the processing speed, and when recording an image on a recording medium, it becomes easy to avoid unnecessary recording of the image and improve the utilization efficiency of the recording medium.

Further, in the present invention, a collision recording system provided on a vehicle for photographing and recording images from before collision to after collision includes one of the above-mentioned image pickup devices to photograph images in a plurality of directions. Along with a sensor that detects the impact and its direction, images of all directions are recorded before the impact is detected, and after the impact is detected, only the image of the direction closest to the direction of the impact is recorded. I shall.

This collision recording system is provided with a sensor for detecting an impact in order to determine the presence or absence of the impact and the direction of the impact when the impact occurs. Until the impact is detected, all images captured by the imaging device in a plurality of directions are recorded. Therefore, even if a collision occurs in any direction, the opponent object before the collision is likely to be recorded in the image. Also,
After the impact is detected, the image in the direction closest to the direction in which the impact is applied is recorded, so there is a high possibility that the image of the opponent object after the collision will be recorded. Moreover, after the impact is detected, there is a high possibility that the image other than the image in the direction closest to the direction in which the impact is applied, that is, the other object after the collision is not photographed, and the usefulness is low even if it is recorded. Since the image is not recorded, the recording medium can be effectively used.

Any one of the above is used as an image pickup device for taking a plurality of images, and the characteristics of the configuration of each image pickup device are utilized. For example, in the configuration in which each optical system includes the first and second polarization elements, the photographing range can be maximized, and in the configuration in which the optical axes of one or more optical systems are decentered, the size can be reduced. Therefore, it is easy to arrange in the vehicle compartment. Further, in the configuration in which the image pickup device regions in which the respective optical systems guide light are arranged in the short side direction of the rectangular image pickup device, a wide range can be photographed in the horizontal direction, and the image pickup device region is arranged in a pixel row. With the arrangement arranged in the vertical direction, it is possible to process the output signal of the image pickup element at a high speed when recording the image after the collision, and it is extremely easy to record only the image in one direction.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an image pickup apparatus and a collision recording system of the present invention will be described below with reference to the drawings. The optical configuration of the image pickup apparatus 1 of the first embodiment is schematically shown in FIG. The image pickup device 1 has a rectangular image pickup element 1.
3, the image sensor 13 is shown in FIG.
Is a top view seen from a direction perpendicular to, a side view seen from a direction parallel to a long side of the image sensor 13, and a side view seen from a direction parallel to a short side of the image sensor 13. It is a figure.

The image pickup apparatus 1 includes, in addition to the image pickup element 13, two image pickup optical systems which guide light to the image pickup element 13 to form an image on its light receiving surface, and a low-pass filter 14 which removes high frequency components. One of the two imaging optical systems is a convex lens 11, a prism 15, and a first polarization filter 1.
7 and a second polarization filter 19, the other of which is a convex lens 12, a prism 16, and a first polarization filter 18.
And a second polarizing filter 20.

Two opposite side surfaces of the prism 15 are trapezoidal, and an upper surface 15a thereof is inclined by 45 ° with respect to a lower surface parallel to the image pickup device 13. Prism 16 is prism 1
Congruent with 5. These two prisms 15, 16
Is an arrangement in which the upper surfaces 15a and 16b are inclined in the direction along the long side of the image sensor 13 and the inclination directions are opposite to each other.
It is joined on the sides. The lower surfaces of the prisms 15 and 16 respectively face one and the other of the two regions obtained by dividing the light receiving surface of the image pickup device 13 into two equal parts in the direction of the short side. The prisms 15 and 16 are made of a material having a small refractive index such as resin, and the upper surfaces 15a and 16a thereof are provided with a reflective film by vapor deposition of metal.

The low-pass filter 14 is the prism 1
It is arranged between the lower surfaces of 5 and 16 and the image sensor 13.
Although not shown, an IR / UV cut filter is joined to the low-pass filter 14 in order to remove infrared light and ultraviolet light and transmit only visible light.

The lens 11 is arranged near the upper side of one short side of the image pickup device 13 so as to face the upper face 15a so that its optical axis AX1 is folded back on the upper face 15a of the prism 15 and orthogonal to the image pickup device 13. Has been done. The lens 12
The optical axis AX2 is arranged on the upper surface 16a of the prism 16 so as to be folded back and orthogonal to the image sensor 13, and is arranged near the other short side of the image sensor 13 so as to face the upper surface 16a.

The lenses 11 and 12 are wide-angle lenses having a short focal length and have the same optical characteristics. The lens 11 is positioned such that the intersection of the optical axis AX1 and the upper surface 15a is displaced from the center of the upper surface 15a and is positioned closer to the prism 16, and the lens 12 is also arranged such that the intersection of the optical axis AX2 and the upper surface 16a is the upper surface 16.
It is arranged so as to be located closer to the prism 15 than the center of a. That is, the optical axes AX1 and AX2 of the lenses 11 and 12 are not located at the center of each of the above-described two regions that divide the light receiving surface of the image sensor 13 into two equal parts, but between the center of each region and the center of the entire light receiving surface. They pass through and are eccentric in the directions toward each other.

The first polarization filters 17 and 18 of the two image pickup optical systems are arranged between the lens 11 and the prism 15 and between the lens 12 and the prism 16, respectively. Both of these polarization filters 17 and 18 selectively transmit linearly polarized light. However, the polarization plane of the linearly polarized light transmitted by the polarization filter 17 and the polarization plane of the linearly polarized light transmitted by the polarization filter 18 are set to be orthogonal to each other. The plane of polarization of the linearly polarized light which is perpendicular to the paper surface of FIG. 1A and is transmitted by the polarization filter 18 is parallel to the paper surface of FIG.

The second polarizing filters 19 and 20 of the two image pickup optical systems are arranged between the prism 15 and the one region of the image pickup device 13 and between the prism 16 and the other region of the image pickup device 13, respectively. And is close to the image sensor 13. These two polarizing filters 19, 20 are
They are provided on the same substrate so that their edges are in contact with each other, and are integrated. Although the low-pass filter 14 may be arranged between the polarization filters 19 and 20 and the image sensor 13, as shown here, the low-pass filter 14 is formed by the prisms 15 and 16 and the polarization filter 19,
It is preferable that the polarizing filters 19 and 20 are arranged between the polarizing filters 19 and 20 because the polarizing filters 19 and 20 can be closer to the image pickup device 13.
The polarization filters 19 and 20 may be provided on the image sensor 13.

The polarization filter 19 is the polarization filter 17
Selectively transmits the linearly polarized light transmitted by the polarizing filter 20, and the polarization filter 20 selectively transmits the linearly polarized light transmitted by the polarizing filter 18. When the linearly polarized light transmitted by the polarizing filters 17 and 18 is set as in the above example, the plane of polarization of the linearly polarized light transmitted by the polarizing filter 19 is as shown in FIG.
The plane of polarization of the linearly polarized light that is parallel to the paper surface of (c) and is transmitted by the polarization filter 20 is perpendicular to the paper surface of FIG. 1 (c).

The structure of the image pickup device 13 is schematically shown in FIG. The image pickup device 13 has a large number of pixels 13p each including a photodiode that performs photoelectric conversion and a storage unit (not shown) that stores and outputs charges generated by the photodiode. They are arranged two-dimensionally within the range of a rectangular light receiving surface that is substantially similar to the rectangle. The range in which the pixels 13p are arranged, that is, the ratio of the length of the light receiving surface in the long side direction to the length of the short side direction is 4: 3,
The aspect ratio of the image sensor 13 is this value.

The image pickup device 13 is a charge coupled device (CCD).
A plurality of vertical transfer paths 13v parallel to the short side, one horizontal transfer path 13h parallel to the long side, and an amplifier 13a for amplifying the output charge of the pixel 13p as a signal.
Have. The vertical transfer path 13v is provided corresponding to each column of the pixels 13p in the short side direction. Image sensor 13
Are controlled so that all the pixels 13p start photoelectric conversion at the same time and end at the same time, and that the accumulated charges are output at the same time for each column of the pixels 13p arranged in the long side direction.

The signal output from the image pickup device 13 is performed as follows. First, the accumulated charge is output from each pixel 13p in the column closest to the horizontal transfer path 13h to the corresponding vertical transfer path 13v, and each vertical transfer path 13v transfers the output charge to the horizontal transfer path 13h. The horizontal transfer path 13h simultaneously receives the charges of the pixels for one column from the vertical transfer path 13, and transfers the received charges to the amplifier 13a. While the horizontal transfer path 13h is transferring charges, the accumulated charge is output to the vertical transfer path 13v from each pixel in the column next closest to the horizontal transfer path 13h, and each vertical transfer path 13v horizontally transfers the output charge. Transfer to road 13h. By repeating such an operation, the accumulated charge is output from all the pixels 13p and amplified, and the signal output from the image pickup device 13 continuously includes the signals of one row of pixels arranged in the long side direction. Will be
Further, the signals of the pixels in the adjacent columns are included after the signals of the pixels in the one column.

The light receiving surface of the image pickup device 13 is schematically shown in FIG. As described above, the image sensor 13 includes two prisms 1
The lower surfaces of 5 and 16 face each other, and the light receiving surface is the prism 1
5 is divided into a first area A1 in which the pixels 5 face each other and a second area A2 in which the prism 16 faces each other.
1 or A2. Since the signal output is performed as described above, the entire output signal from the image sensor 13 includes only the first half including only the signals of the pixels belonging to the first area A1 and the signals of the pixels belonging to the second area A2. It will be divided into two in the latter half. A peripheral portion along the long side of the image sensor 13 is provided with a terminal 13b for inputting a control signal and a driving voltage and outputting a signal.

In the image pickup apparatus 1 having such an optical configuration, light from one direction along the long side of the image pickup element 13 is reflected by the lens 1
One of the imaging optical systems including the first, first polarization filter 17, prism 15, and second polarization filter 19,
The light is guided to the first area A1 of the light receiving surface of the image sensor 13. At that time, the light is made into convergent light by the lens 11, is converted into only a predetermined linearly polarized light by the polarization filter 17, is reflected by the upper surface 15a of the prism 15 toward the image pickup device 13, passes through the polarization filter 19, and is passed through the image pickup device. Thirteen
An image is formed on the area A1 of the light receiving surface of the.

Further, the light from the opposite direction along the long side of the image pickup device 13 is picked up by the other image pickup optical system including the lens 12, the first polarization filter 18, the prism 16 and the second polarization filter 20. It is guided to the second area A2 of the light receiving surface of 13. At that time, the light is made into convergent light by the lens 12, only a predetermined linearly polarized light is obtained by the polarization filter 18, is reflected by the upper surface 16a of the prism 16 toward the image sensor 13, passes through the polarization filter 20, and is transmitted to the image sensor. An image is formed on the area A2 of the light receiving surface of 13.
In this way, two images in mutually opposite directions are simultaneously captured.

Of the light transmitted through the lens 11, the prism 1
Those that do not enter 5 do not reach the image pickup device 13 because they travel straight beside the prism 15 or are reflected by the upper surface 16a of the prism 16. Similarly, of the light that has passed through the lens 12 and does not enter the prism 16, either the light traveling straight beside the prism 16 or the prism 15
Since it is reflected by the upper surface 15a of the above, it does not reach the image sensor 13.

Most of the light incident on the prism 15 and reflected by the upper surface 15a is directed to the first area A1 of the light receiving surface of the image pickup device 13, but a part of the light is transmitted through the joint surface of the prisms 15 and 16. And heads to the adjacent second area A2. Prism 1
Most of the light that has entered 6 and is reflected by the upper surface 16a also goes to the second region A2 of the light receiving surface of the image sensor 13, but some of the light passes through the joint surface of the prisms 15 and 16 and Head to the first area A1. When light that has passed through the cemented surfaces of the prisms 15 and 16 and travels to the adjacent region is incident on each region as it is, a part of another image overlaps the image captured in each of the regions A1 and A2.

However, in the image pickup apparatus 1, the prism 15,
The light incident on 16 is linearly polarized by the first polarization filters 17 and 18, and the polarization filters 17 and 1 are provided between the prisms 15 and 16 and the image sensor 13, respectively.
Since the second polarization filters 19 and 20 that transmit only the linearly polarized light that has passed through 8 are arranged, the prism 1
The light transmitted through the joint surfaces 5 and 16 is polarized by the polarization filter 19
Alternatively, it is blocked by 20 and does not reach the light receiving surface of the image sensor 13. Therefore, each area A of the image sensor 13
No other image overlaps the image captured in 1 or A2.

Since the second polarization filters 19 and 20 are in contact with each other and are close to the light receiving surface of the image pickup device 13, the pixel 13p of the image pickup device 13 is connected to one of the two image pickup optical systems. Is always incident. That is, all the pixels 13p of the image sensor 13 have two areas A
There is no pixel 13p that does not contribute to shooting because it belongs to either 1 or A2. When the row of the pixels 13p is located below the boundary line between the polarization filters 19 and 20, light from both of the two image pickup optical systems is incident on the pixel 13p, but the pixels 13p are photographed. Since it corresponds to only one line of the edge of the captured image, the quality of the captured image is hardly affected even in such a case.

Lenses 11 and 12 are prisms 15 and 16, respectively.
Optical axes AX1, AX folded back on the upper surfaces 15a, 16a of the
2 are eccentric in a direction toward each other, and FIG.
As shown in (b), most of the lenses 11 and 12 overlap each other. Do not decenter the lenses 11 and 12,
That is, it is possible to set the optical axes AX1 and AX2 folded back on the upper surfaces 15a and 16a of the prisms 15 and 16 to pass through the center of the area A1 and the center of the area A2, respectively. The optical configuration of the image pickup apparatus 1 in such a case is schematically shown in the top view of FIG. As can be seen from a comparison between FIG. 1A and FIG. 7, by decentering the lenses 11 and 12 in the direction in which the optical axes AX1 and AX2 approach the center of the entire light receiving surface, the overlap between the two increases, and The overall configuration of the imaging device 1 can be downsized. Lens 11, 12
Even if only one of them is eccentric, the size of the image pickup apparatus 1 is reduced.

The first area A1 and the second area A2 on the light receiving surface of the image pickup device 13 are arranged in the direction of the short side, and each area A1,
A2 is a rectangle having a long side equal to the long side of the entire light receiving surface and a short side equal to ½ of the short side of the entire light receiving surface. Therefore, in each of the areas A1 and A2, an image that is wide in one direction and narrow in the direction orthogonal thereto is captured. Area A
When the image pickup apparatus 1 is arranged such that the boundary line between 1 and A2 is horizontal and one of the areas A1 and A2 is on the other side, two images having a wide horizontal angle of view and a narrow vertical angle of view are obtained. Will be photographed. Such an arrangement is suitable when the outside of the vehicle is photographed from the cabin of the automobile through the window so that most of the captured images represent the outside of the vehicle.

The first area A1 and the second area A2 on the light receiving surface of the image pickup device 13 are the pixels 13 which simultaneously output the accumulated charge.
are aligned in the direction perpendicular to the row of p,
The first half of the output signal of the image sensor 13 includes only the signals of the pixels belonging to the first area A1, and the second half thereof includes the second area A2.
Only the signals of the pixels belonging to are included.
When one of the two images captured in the first and second areas A1 and A2 is necessary and the other is unnecessary, the signal is output only from the pixels belonging to the area A1 or the pixels belonging to the area A2. You can also By doing so, the time required to output the signal and the time required to process the output signal are each halved, and it becomes possible to capture the necessary image in a short cycle. Further, when an image is recorded on the recording medium, the utilization efficiency of the recording medium is doubled.

FIG. 4 shows a schematic circuit configuration of the image pickup apparatus 1. The image pickup apparatus 1 includes an image processing unit 21, a control unit 22, a storage unit 23, and a display unit 24. The image processing unit 21
The output signal of the image sensor 13 is processed to generate image data representing a captured image. The storage unit 23 temporarily stores the image data generated by the image processing unit 21, and the display unit 24 displays the image represented by the image data stored in the storage unit 23. The control unit 22 controls the respective units from the image pickup device 13 to the display unit 24 in synchronization with each other to control the overall operation of the image pickup apparatus 1.

The image pickup device 1 can be used for various purposes. In particular, the image pickup device 1 is used for an automobile to capture and display an image in a direction difficult to see, or when a collision occurs, a collision occurs. It is suitable for capturing and recording images from the front to the post-collision. If the image pickup device 1 is attached to the front left and right center of the automobile, the image pickup device 13 faces forward, and one of the two areas A1 and A2 of the light receiving surface of the image pickup device 13 is on the other side, the image pickup device 13 is horizontally wide. It is suitable for checking the left and right at an intersection with poor visibility, as it allows you to shoot a range. In this case, the image pickup by the image pickup device 13 and the display by the display unit 24 may be always performed during driving, or may be performed as needed. The display unit 24 is arranged at a position where the driver can easily see it.

If the image pickup device 1 is attached to the upper left and right center of the passenger compartment, for example, near the rearview mirror, and the image pickup device 13 faces left or right, one of the areas A1 and A2 is on the other. , A wide front and rear range can be photographed horizontally, which is suitable for recording in the event of a collision. Car collisions often occur at the front or rear, and even when they occur at the sides, the other object before the collision is located in the front, so by shooting a wide area in front and a wide area in the rear It is possible to reliably capture the image of the preceding partner object. Further, each area A in the long side direction of the image sensor 13
By widening the angle of view of 1 and A2 to nearly 180 °, it is possible to capture the image of the opponent object after the collision in either of the areas A1 and A2 even when the side collision occurs. In this case, imaging by the image sensor 13 is always performed during driving.

FIG. 4 also shows a schematic circuit configuration of a collision recording system 3 which is equipped with the image pickup apparatus 1 and captures and records images before and after a collision accident. The collision recording system 3 includes a recording unit 25 that records the image data stored in the storage unit 23, that is, an image captured by the imaging device 1 on a removable recording medium, and an acceleration sensor 26 that detects the impact caused by the collision as acceleration. Is added. The acceleration sensor 26 detects not only the magnitude of acceleration but also its direction. In this configuration, the control unit 22 uses the recording unit 2
It also controls the recording of the image by 5. The control unit 22 constantly monitors the output of the acceleration sensor 26 and determines that a collision has occurred when an acceleration of a predetermined magnitude or more is detected.

Until a collision occurs, the two images photographed in the areas A1 and A2 of the image sensor 13 are stored in the storage unit 23. At this time, after storing an image for a predetermined time (for example, 30 seconds), the oldest image is rewritten with the latest image. As a result, when a collision occurs, the image for the predetermined time immediately before the collision is stored.

When a collision occurs, the acceleration sensor 26
From the output, it is determined which of the shooting direction in the area A1 and the shooting direction in the area A2 is closer to the direction to which the acceleration is applied, the image is shot only in the nearer area, and the image is stored in the storage unit. Store in 23. Then, when the image for a predetermined time (for example, 30 seconds) is stored, the image before the collision and the image after the collision are recorded on the recording medium.

By capturing the image only in the direction close to the direction in which the acceleration is applied, it is possible to quickly perform the process while maintaining a high possibility of capturing the opponent object after the collision. In addition, the utilization efficiency of the recording medium is improved, and the storage unit 23
The storage capacity of can also be reduced.

FIG. 5 schematically shows the relationship between the storage area of the storage unit 23 in the collision recording system 3 and the image to be stored.
In FIG. 5, (a) represents a part of the area in which the image before the collision occurs is stored, and (b) and (c) represents a part of the area in which the image after the collision occurs is stored. Also, (b)
Is the state until half of the predetermined time has elapsed after the collision,
(C) shows the state after 1/2 of the predetermined time has elapsed after the collision. In this example, the direction in which the image is captured in the first area A1 is close to the direction in which acceleration is applied.

Before a collision occurs, as shown in (a),
The image captured in the area A1 and the image captured in the area A2 are alternately and continuously stored in the storage area of the storage unit 23. There is no image captured in the area A2 after the collision occurs, and the images captured in the area A1 are stored in separate storage areas as shown in (b) until half of the predetermined time elapses. To be done. The blank portion in (b) is an area in which no image is stored, and has a size necessary and sufficient for storing each image. After ½ of the predetermined time has elapsed, as shown in (c), the images photographed in the area A1 are sequentially stored in the blank area in (b), and are blank when the predetermined time has elapsed. The parts are gone.

When the image thus stored in the storage unit 23 is recorded on the recording medium, it may be recorded in the arrangement order of (a) and (c), or may be recorded by changing the arrangement. Good. Even if the arrangement order is not changed, the image is recorded in the recording area of the recording medium without any blank space, and the recording capacity is not lost. When the arrangement order is changed during recording, for the image before the collision, the image captured in the area A1 and the image captured in the area A2 are separated so that they are consecutive in the imaging order, and for the image after the collision, It is preferable to arrange them in the order in which they were taken in order of shooting, so that the history of the accident can be easily understood.

In the collision recording system 3, the image pickup device 1 does not need to include the display unit 24. However, if the display unit 24 is provided and the captured image is displayed until an accident occurs, it is possible to confirm the rear side when the vehicle retreats.

FIG. 6 schematically shows the optical configuration of the image pickup apparatus 2 of the second embodiment. Many of the constituent elements of the image pickup apparatus 2 are the same as or similar to the constituent elements of the image pickup apparatus 1, and these constituent elements are denoted by the same reference numerals as those in the first embodiment. 6, (a) is a top view seen from a direction perpendicular to the image sensor 13, (b) is a side view seen from a direction parallel to the long side of the image sensor 13, and (c) is an image sensor 13. It is a side view seen from the direction parallel to the short side of the.

The image pickup device 2 has the same image pickup device 13 as that of the image pickup device 1, two image pickup optical systems for guiding light to the image pickup device 13 to form an image on its light receiving surface, and a low-pass for removing high frequency components. The filter 14 is provided. One of the two image pickup optical systems includes a convex lens 11, a first polarization filter 17 and a second polarization filter 19,
The other is composed of a convex lens 12, a prism 30, a first polarization filter 18, and a second polarization filter 20.

The prism 30 has an isosceles right triangle having two opposing side surfaces, and two orthogonal surfaces 30a, 30.
b is inclined by 45 ° with respect to the lower surface parallel to the image sensor 13. Hereinafter, the surfaces 30a and 30b are referred to as slopes. The prism 30 is arranged such that the slopes 30 a and 30 b are inclined in the direction along the long side of the image sensor 13. Prism 30
The lower surface of the image sensor 13 faces one of two regions obtained by dividing the light receiving surface of the image pickup device 13 into two equal parts in the short side direction. Prism 30
Is made of a material having a small refractive index such as resin, and the slopes 30a and 30b are provided with a reflection film by vapor deposition of metal.

The lens 11 is arranged facing the image pickup device 13 so that its optical axis AX1 is orthogonal to the image pickup device 13. The optical axis AX2 of the lens 12 is the prism 3
It is arranged to face a portion of the lower surface of the prism 30 located below the slope 30a so as to be folded back at two slopes 30a and 30b of 0 and orthogonal to the image sensor 13.

Although the lenses 11 and 12 are both wide-angle lenses having a short focal length, in order to correct the difference in optical path length to the image pickup device 13 and make the image formation state of light on the image pickup device 13 equal, Different optical characteristics are set. Lens 11
Are arranged so that the optical axis AX1 passes between the center of one region of the light-receiving surface of the image sensor 13 and the center of the entire light-receiving surface. In addition, the lens 12 also includes the slope 30 of the prism 30.
The optical axis AX2 folded back at a and 30b is the image sensor 13
Is arranged so as to pass between the center of the other region of the light receiving surface and the center of the entire light receiving surface. That is, the lens 11,
The optical axes AX1 and AX2 of 12 are eccentric from the center of each of the two regions that divide the light receiving surface of the image sensor 13 into two equal parts.

The first polarization filter 17 of one image pickup optical system is arranged near the lens 11, and the second polarization filter 19 is arranged close to the image pickup device 13. The first polarization filter 18 of the other imaging optical system is
The second polarizing filter 20 is arranged between the lens 12 and the lower surface of the prism 30, and the second polarizing filter 20 is arranged between the lower surface of the prism 30 and the image pickup element 30. The second polarization filters 19 and 20 are provided on the same substrate so that their edges are in contact with each other, and are integrated. In this case as well, the second polarization filters 19 and 20 are connected to the image sensor 13
The low-pass filter 14 is disposed between the prism 30 and the second polarizing filters 19 and 20 in order to bring the low-pass filter 14 into close proximity to the.

The relationship between the characteristics of the first and second polarization filters 17, 18, 19 and 20 of the two image pickup optical systems is the same as in the first embodiment. That is, the first polarization filters 17 and 18 selectively transmit one and the other of two linearly polarized lights whose polarization planes are orthogonal to each other, and the second polarization filters 19 and 20 correspond to the first polarization filters 17 corresponding to each other. ,
Only the linearly polarized light transmitted by 18 is transmitted.

In the image pickup apparatus 2 having such an optical structure, the light from the front of the image pickup element 13 is picked up by one of the image pickup optical systems including the lens 11, the first polarization filter 17 and the second polarization filter 19. The light is guided to the first region A1 (see FIG. 3) of the light receiving surface of the element 13. At that time, the light is made into convergent light by the lens 11, is made into only a predetermined linearly polarized light by the polarization filter 17, is transmitted through the polarization filter 19, and is imaged on the area A1 of the light receiving surface of the image sensor 13.

Further, the light from the rear of the image pickup device 13, the lens 12, the first polarization filter 18, the prism 30,
The other imaging optical system including the second polarization filter 20 guides the light to the second area A2 of the light receiving surface of the imaging element 13. At that time, the light is made into convergent light by the lens 12, and only predetermined linearly polarized light is made by the polarization filter 18.
The light is reflected by the two slopes 30a and 30b of the prism 30 toward the image sensor 13, passes through the polarization filter 20, and forms an image on the area A2 of the light receiving surface of the image sensor 13. In this way, two images in mutually opposite directions are simultaneously captured.

Since the first polarization filters 17 and 18 and the second polarization filters 19 and 20 are provided, the lens 1
Part of the light passing through 1 does not enter the second area A2, and part of the light passing through the lens 12 does not enter the first area A1. In addition, the second polarization filter 1
Since 9 and 20 are in contact with each other and are close to the light receiving surface of the image pickup device 13, none of the pixels of the image pickup device 13 contributes to photographing. These situations are exactly the same as the imaging device 1 of the first embodiment.

The lenses 11 and 12 are decentered in a direction in which the former optical axis AX1 and the latter optical axis AX2 folded back by the slopes 30a and 30b of the prism 30 approach each other, and FIG.
As shown in (a) and (b), most of the lenses 11 and 12 overlap each other. Without decentering the lenses 11 and 12, the optical axis AX1 of the lens 11 and the optical axis AX2 of the lens 12 folded back by the slopes 30a and 30b are respectively the areas A1.
It is also possible to set so as to pass through the center of the area and the center of the area A2. The optical configuration of the image pickup apparatus 2 in the case of such setting is schematically shown in the top view of FIG. As can be seen from the comparison between FIG. 6A and FIG. 8, by decentering the lenses 11 and 12 in the direction in which the optical axes AX1 and AX2 approach the center of the entire light receiving surface, the overlap between the two increases, and The overall configuration of the imaging device 2 can be downsized. This is also the imaging device 1
Is the same as.

The circuit configuration of the image pickup apparatus 2 is the same as that of the image pickup apparatus 1, and is as shown in FIG. The imaging device 2 can also be used for various purposes, but in particular, it is used for an automobile to capture and display an image in a direction that is difficult for the driver to see, and when a collision occurs, a collision occurs before the collision. Suitable for shooting and recording subsequent images.

The image pickup device 2 is attached to the front left and right center of the automobile, the image pickup device 13 is oriented rightward or leftward, and one of the two areas A1 and A2 of the light receiving surface is above the other. For example, it is possible to shoot a wide left and right range horizontally, which is suitable for checking the left and right at an intersection with poor visibility. Further, the image pickup device 2 is attached to the upper left and right center of the vehicle compartment, and the image pickup device 13 faces the front or the rear, and the area A
By disposing one of A and A2 on the other, a wide front and rear range can be photographed in the horizontal direction, which is suitable for recording in the event of a collision accident.

Instead of the image pickup device 1, the image pickup device 2 may be provided in the collision recording system 3 described above. Also in this case, the above-mentioned control can be adopted as it is.

In the first and second embodiments, 2
In order to make the polarization characteristics of the light guided by the two imaging optical systems to the image sensor different, an example of using a polarizing filter to make linearly polarized light has been shown, but other types of polarization elements may be used to make the light have different polarization characteristics. May be. For example, each imaging optical system is equipped with a polarizing element having a cholesteric liquid crystal film that selectively transmits only one of clockwise circularly polarized light and counterclockwise circularly polarized light, and the rotational direction of circularly polarized light guided by each imaging optical system. May be reversed. It is also possible to combine such a polarizing element, a quarter-wave plate, and a polarizing filter.

Further, although an example in which an image in the opposite direction is taken is shown here, the shooting direction is not limited to this, and may be set arbitrarily. Further, here, the imaging optical system is 2
Although the configuration is shown in which the light receiving surface of the image sensor is divided into two equal parts, the light receiving surface does not necessarily have to be equally divided, and three or more imaging optical systems are provided to divide the light receiving surface of the image sensor into three parts. Alternatively, it may be divided into more parts.

[0072]

According to the present invention, a plurality of optical systems and one image pickup device are provided,
In an image pickup apparatus that guides light from different directions to different regions of an image pickup device by a plurality of optical systems to form an image, each optical system includes a first polarizing element and an image pickup device separated from the image pickup element as in the present invention. A second polarizing element adjacent to each other, the first polarizing element of each optical system is out of the optical path of the other optical system, and the second polarizing element of each optical system is the first polarizing element of the optical system.
If the polarization component from the first polarization element of the other optical system is blocked by transmitting the polarization component from the other polarization element, it is possible to reliably prevent each image from being overlapped with another image while capturing an image. It becomes possible to utilize all the pixels of the device for photographing.

In an image pickup apparatus having a plurality of optical systems and one image pickup device, the plurality of optical systems guide light from different directions to different regions of the image pickup device to form an image. If the optical axis of the optical system is decentered from the center of the area of the image sensor that guides light, the optical systems approach each other, It becomes smaller as a whole.

In an image pickup apparatus having a plurality of optical systems and a single image pickup element, the plural optical systems guide light from different directions to different regions of the image pickup element to form an image. If the regions of the image pickup device which are rectangular and the optical systems guide the light are arranged in the direction along the short side of the image pickup device, each region of the image pickup device becomes an elongated rectangle and is wide in one direction. Suitable for shooting a narrow area in the orthogonal direction.

In an image pickup apparatus having a plurality of optical systems and a single image pickup device, which guides light from different directions to different regions of the image pickup device by the plurality of optical systems to form an image, as in the present invention, the image pickup device is Assuming that the areas of the image pickup device that output signals for each column of pixels arranged in a predetermined direction and guide the light by each optical system are arranged in a direction perpendicular to the column of pixels of the image pickup element, one region of the image pickup element It is possible to obtain one entire image only by processing the output signals of the pixels included in, and when unnecessary, the processing of the output signals of the pixels included in other regions can be omitted. For this reason, the processing speed is improved, and it is easy to increase the utilization efficiency of the recording medium for recording the image.

In a collision recording system provided on a vehicle for capturing and recording images from before collision to after collision,
According to the present invention, the image pickup device according to any one of the above is provided,
In addition to taking images in multiple directions, it is equipped with a sensor that detects the impact and its direction.Before the impact is detected, images in all directions are recorded, and after the impact is detected, the most impact direction is detected. If only the image in the near direction is recorded, there is a high possibility that the image of the opponent object can be recorded before and after the collision, and further, after the collision, the use efficiency of the recording medium is reduced due to the recording of the less useful image. You can avoid a decline.

Further, the characteristics of the respective constitutions of the image pickup devices are utilized to ensure that a wide photographing range is ensured by utilizing all the pixels of the image pickup element for photographing, and the image pickup device is suitable for being compact and arranged in the vehicle compartment. To obtain a wide range in the horizontal direction so that a useful image can be obtained even when the image is placed in the passenger compartment, or when the image after the collision is recorded, the output signal of the image pickup device is output at high speed. The collision recording system is capable of processing and surely preventing a decrease in utilization efficiency of the recording medium.

[Brief description of drawings]

FIG. 1 is a top view (a) schematically showing an optical configuration of an image pickup apparatus according to a first embodiment and side views (b) and (c) in two orthogonal directions.

FIG. 2 is a plan view schematically showing the configuration of an image pickup device included in the image pickup apparatus according to the first and second embodiments.

FIG. 3 is a plan view schematically showing a light receiving surface of the image sensor.

FIG. 4 is a block diagram showing an outline of a circuit configuration of an image pickup apparatus according to the first and second embodiments and a circuit configuration of a collision recording system including each image pickup apparatus.

FIG. 5 is a diagram schematically showing a relationship between a storage area of a storage unit and an image to be stored in the collision recording system.

FIG. 6 is a top view (a) schematically showing an optical configuration of an image pickup apparatus according to a second embodiment and side views (b) and (c) in two orthogonal directions.

FIG. 7 is a top view schematically showing another setting example of the optical configuration of the image pickup apparatus of the first embodiment.

FIG. 8 is a top view schematically showing another setting example of the optical configuration of the image pickup apparatus according to the second embodiment.

[Explanation of symbols]

1, 2 imaging device 3 collision record system 11, 12 lens 13 Image sensor 13a amplifier 13b Input / output terminal 13h horizontal transfer path 13p pixel 13v vertical transfer path 14 low-pass filter 15, 16 prism 15a, 16a Reflective surface 17, 18 Polarizing filter 19, 20 Polarizing filter 21 Image processing unit 22 Control unit 23 Memory 24 Display 25 recording section 26 Accelerometer 30 prisms 30a, 30b Reflective surface A1, A2 light receiving area AX1, AX2 optical axis

Claims (5)

[Claims] 1. A plurality of optical systems and one image sensor are provided,
In an imaging device that guides light from different directions to different regions of an image sensor by a plurality of optical systems to form an image, each optical system includes a first polarization element separated from the image sensor and a second polarization element close to the image sensor. An optical element, the first polarization element of each optical system is out of the optical path of the other optical system, and the second polarization element of each optical system is polarized light from the first polarization element of the optical system. An image pickup apparatus, which transmits a component and blocks a polarized component from a first polarizing element of another optical system. 2. A plurality of optical systems and one image sensor are provided,
In an imaging device that guides light from different directions to different regions of an image sensor by a plurality of optical systems to form an image, at least one optical system has an optical axis from the center of the region of the image sensor that guides light. The imaging device is eccentric in a direction approaching the center of the imaging element. 3. A plurality of optical systems and one image pickup device are provided,
In an imaging device that guides light from different directions to different regions of an image sensor by a plurality of optical systems to form an image, the image sensor has a rectangular shape, and the area of the image sensor where each optical system guides light is the short side of the image sensor. An image pickup device, which is arranged in a direction along. 4. A plurality of optical systems and one image pickup device are provided,
In an imaging device that guides light from different directions to different regions of an image sensor by a plurality of optical systems to form an image, the image sensor outputs a signal for each row of pixels arranged in a predetermined direction, and each optical system guides the light. An image pickup apparatus, wherein regions of the image pickup device are arranged in a direction perpendicular to a column of pixels of the image pickup device. 5. A collision recording system provided on a vehicle for recording and recording images from before collision to after collision, comprising the image pickup device according to any one of claims 1 to 4, In addition to shooting images in multiple directions, it is equipped with a sensor that detects the impact and its direction.Before the impact is detected, images in all directions are recorded, and after the impact is detected, the most impact direction is detected. A collision recording system characterized by recording only images in the near direction.