JP2006222554A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which is miniaturized and has simple configuration. <P>SOLUTION: A visual light cut filter 2 and an infrared light cut filter 3 are provided in a front side of an imaging device 1 to output a signal in accordance with incident light. The visual light cut filter 2 and the infrared light cut filter 3 are driven by a switching mechanism 4 constituted of an electromagnetic actuator comprising coils 5a, 5b, and a magnet 6. When receiving a switching instruction of a photographing mode from an operation section 8, a control section 7 transmits a switching control signal to the switching mechanism 4 to obtain a corresponding photographing mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention uses a single image sensor and a plurality of optical filters with different transmission wavelengths arranged on the front surface thereof, for example, to switch between normal shooting and night-vision shooting, and capable of shooting day and night. It relates to the device.

  Conventionally, intruders in controlled areas such as airports and power facilities and ecological surveys of natural animals have been detected by intruders and intruders and monitored by captured images using imaging devices using infrared sensors. ing.

  Conventionally, as an imaging device for performing such monitoring, for example, an infrared light cut filter and a visible light cut filter are arranged side by side on the front surface of the image sensor, and each has a peak sensitivity in the visible light region, Based on the output of the light receiving element having peak sensitivity in the infrared light range, the filter change device rotates and drives the infrared light cut filter and visible light cut filter, and a filter corresponding to the wavelength range of the reflected light of the object is obtained. Some of them were selected (see, for example, Patent Document 1).

JP-A-7-284111

  In a conventional imaging device, it is necessary to provide a light receiving element, a signal processing device, and the like in order to select a filter according to the wavelength range of the reflected light from the subject. Further, since the filter is also changed by rotation, the imaging device itself There was a problem that the scale was increased and the installation location was limited.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an imaging apparatus that can be downsized and simplified in configuration.

  In the imaging apparatus according to the present invention, a plurality of optical filters having different transmission wavelength bands are provided on the front surface of an imaging element that outputs a signal corresponding to incident light, and the plurality of optical filters are provided by a switching mechanism using an electromagnetic actuator. It is to be switched.

  In the imaging apparatus according to the present invention, a plurality of optical filters having different transmission wavelength bands are switched by a switching mechanism using an electromagnetic actuator, so that the imaging apparatus capable of switching the optical filter is reduced in size and simplified in configuration. be able to.

Embodiment 1 FIG.
1 is a block diagram showing an imaging apparatus according to Embodiment 1 of the present invention.
In the figure, the imaging apparatus includes an imaging device 1, a visible light cut filter 2, an infrared light cut filter 3, a switching mechanism 4, a control unit 7, and an operation unit 8. The imaging device 1 is an element that outputs an electrical signal corresponding to incident light, such as a CCD (charge coupled device). The visible light cut filter 2 and the infrared light cut filter 3 are optical filters having different transmission wavelength bands, and are provided so as to be adjacent to each other on the front side of the image pickup device 1. The image pickup device 1 includes the visible light cut filter 2. Alternatively, the light is received through the infrared light cut filter 3. The visible light cut filter 2 has a characteristic of cutting light in the visible light region and transmitting only light in the infrared light region. The infrared light cut filter 3 has a characteristic of cutting light in the infrared light region and transmitting light in the visible light region.

  The switching mechanism 4 is a mechanism for driving the visible light cut filter 2 and the infrared light cut filter 3 in a direction parallel to the image sensor 1 by an electromagnetic actuator and switching the type of light incident on the image sensor 1. 5a and 5b and a magnet 6. The coil 5a is a coil provided on the visible light cut filter 2 side of the imaging apparatus body, and the coil 5b is a coil provided on the infrared light cut filter 3 side. The magnet 6 is a magnet fixed to the visible light cut filter 2 and the infrared light cut filter 3, and drives the visible light cut filter 2 and the infrared light cut filter 3 depending on the energization state of the coils 5a and 5b. It is configured. That is, the entire filter is driven by changing the magnetic flux generated by the coils 5a and 5b and moving the attracting position of the magnet 6. The control unit 7 is a functional unit that controls the entire imaging apparatus, and has a function of sending a switching control signal to the switching mechanism 4 based on a shooting mode selection instruction from the operation unit 8. The operation unit 8 includes a switch or the like for switching between the normal shooting mode and the night vision shooting mode.

FIG. 2 is an explanatory diagram showing the configuration of the optical system and the control system as an imaging device and the switching state of the visible light cut filter 2 and the infrared light cut filter 3, and (a) selects the visible light cut filter 2 In this case, (b) shows a case where the infrared light cut filter 3 is selected.
In these drawings, a lens 9 is provided on the front side of the visible light cut filter 2 and the infrared light cut filter 3 and is a lens for forming an image of a subject on the image sensor 1. The AFE / TG 10 is an analog front end / timing generator, and is a module for converting an analog image signal from the image sensor 1 into a digital image signal for processing by the image processing DSP 12 and for adjusting timing. is there. The filter switching driver 11 is a driver for driving the switching mechanism 4 and implements the switching control function of the control unit 7 in FIG. In FIG. 2, the switching mechanism 4 is not shown. The image processing DSP 12 is a processor dedicated to digital signal processing, and the power supply driver 13 is a power supply unit for supplying power to the imaging apparatus. Moreover, even if the visible light cut filter 2 and the infrared light cut filter 3 are switched as the image pickup device, the image pickup element 1 is disposed in the center so that a storage space for these filters can be secured.

Next, the operation of the imaging apparatus configured as described above will be described.
FIG. 3 is a flowchart showing the filter switching operation of the first embodiment.
When there is an imaging mode switching instruction from the operation unit 8 (steps ST1 and ST2), the control unit 7 outputs an actuator drive signal to the switching mechanism 4 according to the corresponding mode (steps ST3 and ST4). . That is, when the normal photographing mode is selected in step ST2, a control signal is output so that the infrared light cut filter 3 is positioned in front of the image sensor 1 (step ST3).

  On the other hand, when the night vision photographing mode is selected in step ST2, a control signal is output so that the visible light cut filter 2 is positioned in front of the image sensor 1 (step ST4). Thereby, a current corresponding to the coils 5 a and 5 b flows, the magnet 6 is driven in a desired direction, and the visible light cut filter 2 or the infrared light cut filter 3 moves to the front surface position of the image sensor 1. That is, when the control at step ST3 is performed, as shown in FIG. 2B, the infrared light cut filter 3 is positioned in front of the image sensor 1, and when the control at step ST4 is performed, As shown in FIG. 2A, the visible light cut filter 2 is positioned in front of the image sensor 1.

  Then, when the control at step ST3 is performed, photographing by the infrared light cut filter 3, that is, photographing in the normal photographing mode is performed (step ST5), and when the control at step ST4 is performed, visible light is obtained. Photographing by the cut filter 2, that is, photographing in the night vision photographing mode is performed (step ST6). Further, the image pickup device 1 outputs an image corresponding to these shooting modes (step ST7).

  As described above, according to the imaging apparatus of the first embodiment, an imaging element that outputs a signal according to incident light, a plurality of optical filters that are arranged in front of the imaging element and have different transmission wavelength bands, A switching mechanism that switches the optical filter with an electromagnetic actuator and a control unit that issues a switching instruction to the switching mechanism are provided, so that an imaging device that can switch the optical filter can be reduced in size and simplified in configuration. . For example, it is possible to realize a small module in which the installation location required for an imaging apparatus for use in a camera for confirming the front of a car, a small surveillance camera, or the like is not limited.

  Moreover, according to the imaging device of Embodiment 1, since the plurality of optical filters having different transmission wavelength bands are configured by the visible light cut filter and the infrared light cut filter, the normal photography and the night vision photography are further performed. There is an effect that can be realized with a simple configuration.

Embodiment 2. FIG.
FIG. 4 is a configuration diagram of the imaging apparatus according to the second embodiment.
The illustrated imaging apparatus includes an imaging device 1, a visible light cut filter 2, an infrared light cut filter 3, a switching mechanism 4 (coils 5a and 5b and a magnet 6), and a control unit 7a. Here, the second embodiment is different from the first embodiment in that the control unit 7a is configured to perform switching control to the switching mechanism 4 based on the output of the imaging element 1. That is, the control unit 7a positions the visible light cut filter 2 in front of the image sensor 1 when the amount of light incident on the image sensor 1 is small, and the infrared light cut filter 3 when the amount of light is large. The switching mechanism 4 is controlled so as to be positioned in front of the image sensor 1. Since the configuration other than this is the same as that of the first embodiment, the same reference numerals are given to corresponding portions, and the description thereof is omitted.

Next, the operation of the second embodiment will be described.
FIG. 5 is a flowchart showing the operation of the second embodiment.
The control unit 7a has a threshold for comparison with the output of the image sensor 1, and when operating as an imaging device, compares the output value of the image sensor 1 with this threshold (step). ST11). This threshold value is appropriately determined depending on the operating conditions of the imaging apparatus. In step ST11, when the output of the image sensor 1 exceeds the threshold value, the control unit 7a outputs a control signal to the switching mechanism 4 so that the infrared light cut filter 3 is positioned in front of the image sensor 1. (Step ST12). On the other hand, when the output of the image sensor 1 is equal to or less than the threshold value in step ST11, the control unit 7a outputs a control signal so that the visible light cut filter 2 is positioned in front of the image sensor 1 (step ST13).

When a control signal for selecting the infrared light cut filter 3 is output in step ST12, photographing through the infrared light cut filter 3 is performed (step ST14). In step ST13, the visible light cut filter is selected. When a control signal for selecting 2 is output, photographing through the visible light cut filter 2 is performed (step ST15). That is, when the amount of light incident on the image sensor 1 is large (when the periphery is bright), shooting is performed in the normal photographing mode, and when the amount of light incident on the image sensor 1 is small (when the periphery is dark). Is switched to night-vision shooting mode.
Thereafter, shooting is performed in each shooting mode, and an image signal is output from the image sensor 1 (step ST16).

  As described above, according to the imaging device of the second embodiment, when the amount of light incident on the imaging device is small, the control unit positions the visible light cut filter in front of the imaging device, and the amount of light is In many cases, since the switching mechanism is controlled so that the infrared light cut filter is positioned in front of the image sensor, in addition to the effects of the first embodiment, the normal shooting mode and the night vision shooting mode are automatically switched. For example, a device such as an unmanned surveillance camera device that can be used day and night can be easily realized.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the imaging device by Embodiment 1 of this invention. It is explanatory drawing which shows the switching state of the filter of the imaging device by Embodiment 1 of this invention. It is a flowchart which shows the filter switching operation | movement of the imaging device by Embodiment 1 of this invention. It is explanatory drawing which shows an example of the reading part and operation part of the other device in Embodiment 1 of this invention. It is a flowchart which shows the filter switching operation | movement of the imaging device by Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pick-up element, 2 Visible light cut filter, 3 Infrared light cut filter, 4 Switching mechanism, 5a, 5b Coil, 6 Magnet, 7, 7a Control part, 9 Lens.

Claims (3)

An image sensor that outputs a signal according to incident light;
A plurality of optical filters with different transmission wavelength bands arranged on the front surface of the imaging device;
A switching mechanism for switching the plurality of optical filters with an electromagnetic actuator;
An imaging apparatus comprising: a control unit that issues a switching instruction to the switching mechanism.   The imaging apparatus according to claim 1, wherein the plurality of optical filters having different transmission wavelength bands include a visible light cut filter and an infrared light cut filter. The control unit
When the amount of light incident on the image sensor is small, the visible light cut filter is positioned in front of the image sensor, and when the amount of light is large, the infrared light cut filter is positioned in front of the image sensor. The imaging apparatus according to claim 2, wherein the switching mechanism is controlled.

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