JPS62141863A - Image pickup device - Google Patents

Abstract

PURPOSE:To obtain an image pickup device with small size and less fault by providing two liquid crystal shutters provided to each optical path of a front lens and a side lens and an electric circuit giving an opposite drive voltage to the said two liquid crystal shutters to each other. CONSTITUTION:Each image of the front lens 2 and the side lens 4 is picked up by a CCD (charge coupling device) type camera 7. The CCD type camera 7 is moved by a distance L by a focus motor 8. A mirror 11 is a half mirror transmitting the collected light of the front lens 2 and reflecting the collected light of the side lens 4, and the two liquid crystal shutters, the liquid crystal shutter 12 provided to an optical path of the front lens 2 and the liquid crystal shutter 13 provided to the optical path of the side lens 4 and an electric circuit giving an opposite drive voltage to the two liquid crystal shutters 12, 13 are provided. That is, the liquid crystal shutter 12 on the light collection path of the front lens (not shown in figure) making a light incident as shown in the arrow A and the liquid crystal shutter 13 on the light collection path from the side lens (not shown in figure) making a light incident as shown in the arrow B similarly are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is suitable for use as an in-pipe monitoring camera that is inserted into a long and narrow place such as a pipe to observe the internal situation.

〔overview〕

The present invention provides an imaging device that includes an image sensor in an outer shell, a lens provided in two directions of the outer shell, and a mirror that reflects one optical path of the lens, in which the mirror is a half mirror. By providing a liquid crystal shutter that operates with mutually opposing drive voltages between the two lenses, the number of mechanically driven parts in the outer shell can be reduced, making it small and lightweight, and preventing failure even in poor environments. This provides a device with fewer

[Conventional technology]

In-pipe monitoring cameras, which are equipped with an image sensor and a lens inside an outer shell, are used to observe the status of cable wiring installed in narrow spaces such as pipes.

Conventionally, this type of imaging device was used with a lens system installed only at the front of the outer shell, but in order to observe the details of conduits and cable wiring in more detail, an effective lens system was installed on the side of the outer shell. Those equipped with an optical system and capable of capturing images of the external situation in these two directions are used.

[Problem that the invention seeks to solve]

However, for this reason, it becomes expensive to provide each optical system with two imaging devices, and it is not possible to make the system compact.

In addition, the type that manually inserts a movable mirror into the optical path of the front lens and manually captures the image of the side lens onto a single image sensor has the drawback that the mirror has a movable mechanism, which is prone to failure and increases the size of the device. was there.

SUMMARY OF THE INVENTION An object of the present invention is to solve these drawbacks and provide an imaging device that is small and has fewer failures.

[Means for solving problems]

The present invention includes an image sensor, a front lens that forms a front image on the surface of the image sensor, a side lens that forms a side image on the image sensor, and a light condensing element of the side lens. In an imaging device including a reflecting mirror in an outer shell,
The mirror is a half mirror that transmits the condensed light of the front lens, and has two liquid crystal shutters provided in each optical path of the front lens and the side lens, and driving voltages that are opposite to each other are applied to these two liquid crystal shutters. The invention is characterized in that it is equipped with an electric circuit that provides.

Two liquid crystal shutters are provided between the front lens and the mirror and between the side lens and the mirror, respectively.
The half mirror has a transmittance of 70-90% on the front lens side.
and the reflectance on the side lens side is 10 to 30%,
Preferably, the side lenses have a wider angle than the front lenses and are entirely mounted in a generally cylindrical outer shell.

The outer shell may include lighting means.

[Effect]

Since the mirror is a half mirror, even if it is fixed, light from lenses in two directions can be guided to one imaging element. Since the liquid crystal shutters provided in the optical paths of the respective lenses perform contradictory operations based on one system of signals, no mechanically movable parts are required to switch the optical paths.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of the external appearance of the above embodiment, in which a front lens 2 and an illumination port 3 are provided in front of a cylindrical outer shell l, and side lenses 4 are provided on the side surfaces.
and an illumination port 5, which are attached to support means (not shown) via a ring 6 shown in broken lines.

FIG. 2 is a schematic cross-sectional view of the above embodiment, and each image of the front lens 2 and the side lens 4 is imaged by a COD (charge-coupled device) type camera 7. This CC
The D-type camera 7 is moved by the distance dimension by the focus morph 8.

Here, the features of the present invention are that one is that the mirror 11 is a half mirror that transmits the light condensed by the front lens 2 and reflects the condensed light of the side lens 4; Two liquid crystal shutters, a liquid crystal shutter 12 provided in the optical path of the side lens 4 and a liquid crystal shutter 13 provided in the optical path of the side lens 4, and electric circuits that apply mutually opposing driving voltages to these two liquid crystal shutters 12 and 13 are provided. It is in.

That is, in the block configuration diagram of the electric circuit of this embodiment shown in FIG. A liquid crystal shutter 13 is provided on the light collection path from the outer side lenses.

The drive electrode of the liquid crystal shutter 12 is connected to the output of the drive circuit 16, and the drive electrode of the liquid crystal shutter 13 is connected to the output of the drive circuit 17. The control signal terminal 15 is connected to the human power of the drive circuit 17, and the input of the drive circuit 16 is connected to the human power of the drive circuit 17.
connected to the output of Here, the drive circuit 16 is constituted by an inverting amplifier, and drive voltages opposite to each other are applied to each drive electrode of the liquid crystal shutters 12 and 13.

In FIG. 2, the light from a lamp 21 is guided by a light guide 22 to a front illumination port 3, and is also guided to a side illumination port 4 via a light guide 23 and a prism 24. An image of a target object is focused by the front lens 2 or the side lens 4.

The light collected by the front lens 2 passes through a fixed liquid crystal shutter 12 and a fixed half mirror 11, and is projected onto the surface of a CCD camera 7. In this case, the transmittance of the half mirror 11 is preferably in the range of 70 to 90%. The side lenses 4 have a wider field of view than the front lens 2, and the light collected by these lenses passes through the liquid crystal shutter 13,
The light is reflected by a half mirror 11 and projected onto a CCD camera. At this time, the reflectance of half mirror 11 is 10 to 30%.
It is preferable that it is in the range of .

Light for illuminating the front image is projected at an oblique angle, and light for illuminating the side images is projected from the front. Therefore, the amount of reflected light from the front image that enters the front lens is smaller than the amount of reflected light from the sides. However, since the amount of light incident on the CCD camera from the front and the side must be approximately equal, the ranges of the respective values of transmittance and reflectance of the half mirror as described above are is set.

Since the liquid crystal shutters 12 and 13 have shutter operations for transmitting light that are opposite to each other for the input signal at the terminal 15, one of the liquid crystal shutters 12 and 13 is always projected onto the half mirror 11.

In this embodiment, the front lens is first used to move the inside of the pipe sequentially for observation, then the movement of the outer shell is stopped at important points, and detailed monitoring is performed by switching to the side lens. Since in this case the outer shell is rotated about the axis in the direction of movement at that point, it is advantageous for the outer shell to have a substantially cylindrical shape.

As described above, in this embodiment, the CCD type camera does not have any mechanically movable parts other than being slightly moved by focus morph.

〔Effect of the invention〕

According to the present invention, the imaging device is capable of capturing images in two directions with one single imaging element, and has no mechanically movable parts such as a mirror or a shutter. This has the effect of making it possible to manufacture a device that is small in size, lightweight, and has stable switching operations for the lenses used.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the above embodiment. FIG. 3 is a block diagram of the electric circuit of the above embodiment. 1... Outer shell, 2... Front lens, 3.5... Illumination port, 4... Side lens, 6... Ring, 7... C
CD type camera, 8... Focus morph, 11...
Half mirror 112, 13...LCD shutter, 15.
...terminal, 16.17...drive circuit, 21...lamp, 22.23...light guide, 24...prism. Patent Applicant TID Co., Ltd. Agent Patent Attorney Naotaka Ide, Kei 2 Diagram Cross-sectional schematic diagram Block configuration diagram of electric circuit 33 Diagram

Claims (6)

[Claims] (1) An image sensor, a front lens that forms a front image on the surface of this image sensor, a side lens that forms a side image on this image sensor, and a reflector that reflects the condensed light of this side lens. In the imaging device, the mirror is a half mirror that transmits the condensed light of the front lens, and two liquid crystal shutters are provided in each optical path of the front lens and the side lens. , and an electric circuit that applies mutually contradictory driving voltages to the two liquid crystal shutters. (2) The imaging device according to claim (1), wherein the two liquid crystal shutters are provided between the front lens and the mirror and between the side lens and the mirror, respectively. (3) The half mirror has a transmittance of 70~ on the front lens side.
90%, and the reflectance on the side lens side is 10 to 30%. (4) The imaging device according to claim (1), wherein the side lenses have a wider angle than the front lenses. (5) The imaging device according to claim (1), wherein the outer shell has a generally cylindrical shape as a whole. (6) The imaging device according to claim (1), wherein the outer shell includes illumination means.