JP2010056927A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform photographing without being affected by external light from a second observation area, using an imaging apparatus which includes an observed area to dispose an object to be observed therein and a first observation area to dispose therein a camera for imaging the object to be observed, the object being visible from the second observation area that is an area separated from the first and second observation areas. <P>SOLUTION: Between the observed area 12 and the first observation area 14, a first polarizer 30 is disposed for transmitting only a first linearly polarized component polarized in a predetermined first direction and between a second observation area 16 and the observed area 12, a second polarizer 32 is disposed for transmitting only a second linearly polarized component in a direction approximately orthogonal to the first direction. When light from a second light source 28 passes through the second polarizer 32, only the second linearly polarized component is passed and reflected on an object 20 to be observed. Thereafter, the second linearly polarized component can not be passed through the first polarizer 30, so that the light from the second light source 28 reaches a camera 22 while being attenuated. Thus, on a screen imaged by the camera 22, the influence of light from the second light source 28 is reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging apparatus that images an object to be observed.

  As a conventional imaging device for imaging this type of object to be observed, for example, the display unit of each usage meter such as water, electricity, gas, etc. is used as the object to be observed, and the display unit for displaying the usage is imaged. An apparatus is known from US Pat.

  These imaging devices are for automatically or remotely imaging the display unit for the purpose of reducing the burden on the meter reader, etc., and include at least a light source for irradiating the display unit with light and a display unit. And a camera for imaging.

  An imaging signal that has been captured by a camera and converted into an electrical signal can be transmitted to a base station by being transmitted wirelessly or by wire, or by recording on a recording medium and collecting the recording medium. At the base station, the operator can visually read the contents of the display section while viewing the imaging screen, or the contents of the display section can be automatically read using optical character recognition software (OCR).

  Further, in Patent Document 2, as an imaging apparatus that enables image reading without being affected by visual reading and external light, the display unit is covered with a cover that is a film body that reflects infrared light and transmits visible light. Then, a remote meter reading terminal device including an infrared light emitter and an infrared electronic camera for imaging a display unit in a cover is proposed. According to this, since the infrared rays in the outside light are reflected by the film body and cannot reach the inside of the cover, the inside of the cover becomes a dark box with respect to the infrared rays, and thus the display is not affected by the outside light. Can be imaged.

JP-A-6-152775 JP 2001-101379 A

  However, in the configuration as in Patent Document 2, the film body transmits visible light, and the visible light can pass through the cover. Therefore, the camera has a characteristic that is not affected by visible light. There is a problem that it is necessary, and it is difficult to select and adjust the camera, resulting in a high cost.

  The present invention has been made in view of such a problem, and an object of the present invention is to perform imaging with a camera without being affected by external light or the like at a low cost in an imaging apparatus that enables imaging and viewing with a camera. It is an object of the present invention to provide an imaging device that can be used.

In order to solve the above-described problem, the present invention includes an observation area where an observation object is to be arranged, and a first observation area including a first observation point where a camera for imaging the observation object is arranged. In the imaging apparatus, the object to be observed is visible from a second observation point in a second observation region at a position different from the first observation point.
A first light selection means provided between the observed region and the first observation region, for selectively transmitting light between the observed region and the first observation region; a second observation region; and the observed region And a second light selection means that selectively transmits light between the second observation region and the observation region, and the first light selection means is provided by the second light selection means. It has a characteristic that it does not substantially transmit the transmitted light component.

  Here, “the first light selection unit does not substantially transmit the light component transmitted by the second light selection unit” means that the first light selection unit transmits the light component that can be transmitted by the first light selection unit. The transmittance of the light component transmitted by the two light selection means is sufficiently low by the first light selection means, and the visibility of the imaging screen of the camera by the light component transmitted through both the second light selection means and the first light selection means It means that the influence of can be ignored.

  According to a second aspect of the present invention, there is provided the light source according to the first aspect, further comprising a light source that is disposed in the observed region and that irradiates the observed object with light including a light component that can be transmitted by the first light selection unit. It is characterized by providing.

According to a third aspect of the present invention, there is provided a camera disposed at a first observation point for imaging an object to be observed, from a second observation point in a second observation region at a position different from the first observation point. In the imaging apparatus in which the observation object is visible,
A first light selection unit that is arranged on an optical path from the object to be observed to the camera and selectively transmits light; and an arbitrary light source in the second observation region and an optical path to the object to be observed. And second light selection means for selectively transmitting light, wherein the first light selection means has a characteristic of substantially not transmitting light components transmitted by the second light selection means.

  Here, “the first light selection unit does not substantially transmit the light component transmitted by the second light selection unit” means that the first light selection unit transmits the light component that can be transmitted by the first light selection unit. The transmittance of the light component transmitted by the two light selection means is sufficiently low by the first light selection means, and the visibility of the imaging screen of the camera by the light component transmitted through both the second light selection means and the first light selection means It means that the influence of can be ignored.

  The invention according to claim 4 is a polarizer in which the first light selection means and the second light selection means according to any one of claims 1 to 3 substantially pass only linearly polarized light components in different directions. It is characterized by being.

  Here, “substantially pass only linearly polarized components in different directions” means that the linearly polarized light transmitted by the second light selecting unit is transmitted with respect to the transmittance of the linearly polarized component transmitted by the first light selecting unit. The transmittance of the component by the first light selection means is sufficiently low, and the influence of the light component transmitted through both the second light selection means and the first light selection means on the visibility of the imaging screen of the camera is negligible. Say.

  According to a fifth aspect of the present invention, the first light selection unit and the second light selection unit according to any one of the first to third aspects substantially overlap each other in a frequency band that can be captured by the camera. It is a frequency filter having no frequency pass band.

  Here, “having frequency pass bands that do not substantially overlap each other” means that the second light selection means transmits the light component in the frequency pass band that is transmitted by the first light selection means. The transmittance of the light component by the first light selection means is sufficiently low, and the influence on the visibility of the imaging screen of the camera by the light component transmitted through both the second light selection means and the first light selection means is negligible Say that.

  According to the present invention, the object to be observed can be visually observed from the second observation point at a position different from the camera arranged at the first observation point, and the outside of the second observation region where the second observation point exists is outside. When the light is incident on the object to be observed, the light is selectively transmitted by the second light selection unit, and the first light selection unit does not transmit the selectively transmitted light component. Therefore, it is possible to prevent the outside light from substantially reaching the camera, and it is possible to take an image with the camera without being influenced by the outside light. Since no special selection / adjustment of the camera for removing external light is required, the camera can be configured at low cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating the principle of an imaging apparatus according to the present invention. In the figure, the areas can be broadly divided into an observed area 12, a first observation area 14, and a second observation area 16. The imaging apparatus 10 includes the observed area 12 and the first observation area 14.

  An observed object 20 is arranged in the observed area 12. A camera 22 for imaging is arranged at the first observation point in the first observation region 14. The second observation point 24 in the second observation region 16 is an observation point for human viewing.

  When the observation object 20 does not emit light, a first light source 26 that can irradiate the observation object 20 is disposed in the observation region 12 as illumination for the camera 22.

  In the second observation region 16, there is a second light source 28 that generates external light for enabling visual observation from the second observation point 24 and / or other unnecessary external light. Therefore, the number of the second light sources 28 is not limited to one.

  The camera 22 normally has light receiving sensitivity with respect to the light emitted from the second light source 28. For this reason, when strong external light from the second light source 28 is irradiated onto the object 20 to be observed, a locally high-luminance portion is generated, and that portion is reflected on the imaging screen of the camera 22 and is reflected from the imaging screen. A situation occurs in which the observation object 20 cannot be recognized correctly.

  Therefore, the first light selection unit 30 is disposed between the observed region 12 and the first observation region 14, and the second light selection unit 32 is disposed between the second observation region 16 and the observed region 12. The second light selection unit 32 has a characteristic of selectively transmitting light between the second observation region 16 and the observation region 12, and the first light selection unit 30 includes the observation region 12 and the first observation region. 14, the light transmitted by the second light selection means 32 is not substantially transmitted.

  As a specific example of the first light selection unit 30 and the second light selection unit 32, a first polarizer and a second polarizer can be used. The first polarizer 30 transmits only the first linearly polarized light component polarized in a predetermined first direction between the observed region 12 and the first observation region 14, and the second polarizer 32 transmits the second observation. Only the second linearly polarized light component that is substantially orthogonal to (or in a different direction from) the first direction is transmitted between the region 16 and the observed region 12.

  The first light source 26 (the observed object 20 when the observed object 20 emits light) and the second light source 28 are ordinary light sources. The light from the first light source 26 (circle A in FIG. 1) is reflected by the object to be observed 20, and only the first linearly polarized light component passes through the first polarizer 30 and reaches the camera 22. On the other hand, since the light from the second light source 28 (circle B in FIG. 1) passes through the second polarizer 32, only the second linearly polarized light component passes therethrough. , It is absorbed (or reflected) by the first polarizer 30 and reaches the camera 22 in an attenuated state. Therefore, the imaging screen imaged by the camera 22 has a reduced influence of light from the second light source 28, and can be an imaging screen that can be correctly recognized.

  At the time of observation at the second observation point 24, the light from the first light source 26 (circle A in FIG. 1) is reflected by the observation object 20, and only the second linearly polarized light component is reflected in the second polarizer 32. Pass through and reach the second observation point 24. Further, when the light from the second light source 28 (circle B in FIG. 1) passes through the second polarizer 32, only the second linearly polarized light component passes through and is reflected by the object to be observed 20, and then the second light. The second linearly polarized light component passes through the polarizer 32 as it is and reaches the second observation point 24. Therefore, visual observation at the second observation point 24 can be performed without hindrance. When the external light from the second light source 28 directly hits the observation object 20 and the observation object 20 appears to shine, the position of the second observation point 24 is changed as appropriate, or the second light source 28 Since it can be adjusted by manually blocking external light from the light source, it can be recognized correctly.

The first light selection unit 30 and the second light selection unit 32 may be configured by a frequency filter that selects a frequency component in addition to the polarizer that selects the polarization component. In this case, as shown in FIG. 4, the first light selection unit 30 is configured to generate a light component in a predetermined first frequency band (from f ₁ to f ₂ ) between the observed region 12 and the first observation region 14. The second light selection means 32 transmits only the light component in the second frequency band (from f ₂ to f ₃ ) between the second observation region 16 and the observed region 12 and at least the camera. In the frequency band 22 can be imaged, the first frequency band and the second frequency band do not overlap. The first light source 26 (observed object 20 when the observed object 20 self-emits) emits light including at least a light component in the first frequency band, and the second light source 28 is in the first frequency band. And light components including light components in the second frequency band may be emitted, and the frequency bands of the light emitted from both light sources 26 and 28 may completely overlap.

  The first light source 26 is arranged in the observed region 12 in the example of FIG. 1, but can be arranged in the first observation region 14. In that case, the light from the first light source 26 can also pass through the first light selection means 30, be reflected by the observation object 20, pass through the first light selection means 30 again, and reach the camera 22. .

  FIG. 2 is a longitudinal sectional view of an imaging apparatus constructed according to the principle of the present invention, and FIG. 3 is a sectional view taken along line 3-3 in FIG.

  In the figure, the imaging apparatus 10 includes a case 52 made of an opaque material that does not transmit visible light as a whole.

  An object to be observed 20 is arranged in a region corresponding to the region to be observed 12 in the case 52. In this example, the observed object 20 is a number represented on each rotating drum 54 that is a part of the plurality of rotating drums 54 arranged in parallel corresponding to the plurality of digits.

  In the case 52, a first light source 26 for irradiating the observation object 20, a camera 22 disposed at a first observation point for imaging the observation object 20, and light from the observation object 20 And a mirror 56 that reflects toward the camera 22. The 1st light source 26 can be comprised by LED etc., and shall emit the light of the arbitrary wavelengths of a visible region. The camera 22 can be composed of a CCD camera or the like, and has light receiving sensitivity with respect to the wavelength of the light source 26. A power source and a control circuit (not shown) are disposed in the case 52.

  An opening window 60 is formed in a part of the case 52, and an arbitrary point on the outside of the case 52 where the object 20 can be viewed through the opening window 60 is the second observation point 24. Become. In this example, the opening window 60 is provided at a position facing the object to be observed 20. Then, external light such as sunlight, car headlamps, incandescent lamps, and flashlights outside the case 52 becomes the second light source 28. The position of the second light source 28 is variable and does not always exist.

  In this example, the first optical path 62 for observing the object 20 to be observed by the camera 22 at the first observation point is reflected by the object 20 from the first light source 26, reflected by the mirror 56, and the first observation. It becomes an optical path toward the point. In addition, the second optical path 64 for observing the observation object 20 visually at the second observation point 24 passes through the opening window 60 from the second light source 28, reflects off the observation object 20, and passes through the opening window 60. An optical path toward the second observation point 24 or an optical path reflected from the first light source 26 by the object to be observed 20, passing through the aperture window 60, and toward the second observation point 24.

  The first polarizing film as the first light selecting means 30 is on the first optical path 62 between the observed object 20 and the camera 22 except for the position where the first optical path 62 and the second optical path 64 intersect or overlap. The second polarizing film as the second light selection means 32 is provided between the second light source 28 and the observation object 20 except for a position where the first optical path 62 and the second optical path 64 intersect or overlap each other. It is arranged on the second optical path 64 therebetween. Specifically, the first polarizing film 30 is disposed immediately before the camera 22, and the second polarizing film 32 is disposed in the opening window 60. With this arrangement, the observed region 12 and the first observation region 14 are set in the case 52, and the second observation region 16 is set outside the case 52.

  In the imaging apparatus configured as described above, the light emission of the first light source 26 and the imaging by the camera 22 are performed periodically or at appropriate times by remote operation. During imaging by the camera 22, when external light from the second light source 28 such as sunlight, a car headlamp, or an incandescent lamp enters through the opening window 60 and is irradiated on the observation object 20, A portion with high brightness is locally generated, and the portion is shined on the imaging screen of the camera 22 and the object to be observed 20 cannot be recognized.

  However, as described with reference to FIG. 1, only the second linearly polarized light component can enter the case 52 by the second polarizing film 32, but the first polarized light before entering the camera 22. Since the passage is blocked by the film 30, the external light reaching the camera 22 is attenuated, and imaging can be performed with almost no influence from the external light.

  On the other hand, since the light from the first light source 26 includes both the first linearly polarized light component and the second linearly polarized light component, only the first linearly polarized light component is transmitted to the camera 22 by the first polarizing film 30. In order to reach, the object 20 irradiated by the first light source 26 is imaged.

  Note that when direct light from the first light source 26 is irradiated on the observation object 20 and reaches the camera 22, as in the case of external light, a locally high-brightness portion is obtained, and that portion is displayed on the imaging screen captured by the camera 22. May become unrecognizable, so that the light travels straight from the first light source 26 and enters the object 20 to be observed. The light reaching the point (direct light) does not exist, and only light (indirect light) that travels straight and does not satisfy the relationship of incident angle = reflection angle at the object to be observed 20 is observed at the first observation point. It is desirable to set the position of the first light source 26 so as to reach. As a result, when the image is taken by the camera 22, it is possible to obtain a good imaging screen having uniform brightness without being affected by the external light and the direct light of the first light source 26.

  When it is desired to directly observe the observation object 20 with the naked eye, the observation object 20 is visually observed from the second observation point 24. At this time, in the case where the observation object 20 is illuminated by external light, the position where the observation object 20 can be visually recognized can be searched by appropriately adjusting the position of the second observation point 24. This is because the camera 22 at the first observation point is fixed and there is no degree of freedom, whereas the visual observation at the second observation point has a degree of freedom at that position.

  In this way, the light from the first light source 26 mainly reaches the camera 22 without being affected by outside light, so that the object 20 can be imaged with uniform brightness. The imaging signal converted into an electrical signal by the camera 22 is sent to the base station via wireless, wired or recording medium, and is visually observed by an operator or using optical character recognition software (OCR) at the base station. Thus, the number of the observation object 20 is automatically read. At that time, reading can be performed reliably.

  Moreover, although the example shown in FIG.2 and FIG.3 was an example which applied the imaging device to the meter-reading apparatus, it is not restricted to this, It can apply to arbitrary monitoring imaging devices. For example, the imaging device of the present invention can be applied as a monitoring device that images a workpiece or a related part in order to monitor whether the workpiece is processed correctly, as a workpiece, as an observation object. At this time, the workpiece or related part can be imaged with a camera, and the workpiece can be visually monitored from the second observation point.

It is explanatory drawing showing the principle of the imaging device of this invention. It is a longitudinal cross-sectional view of the imaging device of this invention. FIG. 3 is a cross-sectional view taken along line 3-3 of the imaging apparatus of FIG. It is a graph which shows each passing frequency characteristic of the 1st light selection means and the 2nd light selection means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Imaging device 12 Observed area 14 First observation area 16 Second observation area 20 Observed object 22 Camera 24 Second observation point 26 First light source 30 First light selection means (first polarizer)
32 Second light selection means (second polarizer)

Claims (5)

An observation area in which an observation object is to be arranged, and a first observation area including a first observation point in which a camera for imaging the observation object is arranged, and at a position different from the first observation point In the imaging device in which the observation object is visible from a second observation point in a second observation region,
A first light selection means provided between the observed region and the first observation region, for selectively transmitting light between the observed region and the first observation region; a second observation region; and the observed region And a second light selection means that selectively transmits light between the second observation region and the observed region, and the first light selection means is provided by the second light selection means. An imaging apparatus characterized by having a characteristic of substantially not transmitting a transmitted light component.   The imaging apparatus according to claim 1, further comprising a light source that is disposed in the observation region and that irradiates the observation object with light including a light component that can be transmitted by the first light selection unit. A camera disposed at a first observation point for imaging the observation object; and the observation object is visible from a second observation point in a second observation region at a position different from the first observation point. In the imaging device
A first light selection unit that is arranged on an optical path from the object to be observed to the camera and selectively transmits light; and an arbitrary light source in the second observation region and an optical path to the object to be observed. And second light selection means for selectively transmitting light, wherein the first light selection means has a characteristic of substantially not transmitting light components transmitted by the second light selection means. apparatus.   4. The imaging according to claim 1, wherein the first light selection unit and the second light selection unit are polarizers that substantially pass only linearly polarized light components in different directions. 5. apparatus. The first light selection means and the second light selection means are frequency filters having frequency pass bands that do not substantially overlap each other in a frequency band that can be captured by a camera. The imaging device according to any one of the above.

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