JP2016080844A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of prolonging the service life of illumination means and preventing the degradation of image quality.SOLUTION: An imaging apparatus 10 includes a housing 11, an imaging element 12 which is provided in the front center part of the housing 11 and images a predetermined range, an illumination part 13 which is arranged adjacent to the imaging element 12 and illuminates the imaged predetermined range, an illuminance sensor 14 which detects ambient illuminance, and an illumination control part 15 which decreases the light quantity of illumination light from the illumination part 13 as illuminance detected by the illuminance sensor 14 becomes higher.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus.

  2. Description of the Related Art Conventionally, an imaging device that images a predetermined range in a vehicle interior has been proposed. This imaging apparatus includes illumination means such as an infrared light emitting diode so that a predetermined range of imaging can be performed at night or the like (see Patent Document 1).

JP 2010-253987 A

  However, in the above imaging device, a predetermined range is illuminated by the illumination means even in a slightly dark environment such as evening, and therefore, the illumination is performed with an excessive amount of light, which is a factor for shortening the life of the illumination means. It was. Furthermore, by illuminating with an excessive amount of light, the predetermined range becomes too bright, resulting in a decrease in the quality of the captured image.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an imaging apparatus capable of extending the life of an illuminating unit and preventing deterioration in image quality. It is to provide.

  The imaging apparatus of the present invention is detected by an imaging unit that images a predetermined range, an illumination unit that illuminates the predetermined range imaged by the imaging unit, an illuminance sensor that detects ambient illuminance, and the illuminance sensor. And a light amount control unit that decreases the amount of illumination light from the illumination unit as the illuminance increases.

  According to the imaging apparatus of the present invention, the amount of illumination light decreases as the detected illuminance increases, so that the predetermined range is not illuminated with an excessive amount of light in a slightly dark environment such as in the evening. It is difficult to shorten the lifetime, and it is also possible to prevent the predetermined range from being excessively brightened. Therefore, it is possible to extend the life of the illumination means and prevent the image quality from deteriorating.

  In this imaging apparatus, the illumination unit is one or a plurality of light emitting elements, and the light amount control unit decreases the value of the current supplied to each of the light emitting elements as the illuminance detected by the illuminance sensor increases. It is preferable.

  According to this imaging apparatus, the higher the illuminance detected by the illuminance sensor, the lower the value of the current supplied to each light-emitting element. Therefore, the amount of illumination light from each light-emitting element is suppressed, and the length of the illumination means is reduced. It is possible to extend the life and prevent the image quality from being deteriorated.

  In this imaging apparatus, it is preferable that the illumination unit includes a plurality of light emitting elements, and the light amount control unit reduces the number of light emitting elements that emit light as the illuminance detected by the illuminance sensor increases.

  According to this imaging apparatus, the higher the illuminance detected by the illuminance sensor, the smaller the number of light emitting elements that emit light. It is possible to extend the life and prevent the image quality from being deteriorated.

  In the imaging apparatus, when the light quantity control unit emits a predetermined number of light emitting elements of one or more and less than the plurality, the predetermined number of light emitting elements differ from the predetermined number of previously emitted light emitting elements by at least one. It is preferable that the device emits light.

  According to this imaging apparatus, when a predetermined number of light emitting elements of one or more and less than a plurality are made to emit light, the predetermined number of light emitting elements are made to emit light by making at least one different from the predetermined number of light emitting elements previously emitted. In the case where some of the light emitting elements emit light, only the same light emitting element can be prevented from emitting light, the light emitting elements that emit light can be equalized, and the lifetime of each light emitting element can be extended.

  In this imaging apparatus, the light amount control means may decrease the duty ratio indicating the ratio of the voltage ON time with respect to one cycle of the voltage supplied to the illumination means as the illuminance detected by the illuminance sensor increases. preferable.

  According to this imaging apparatus, the higher the illuminance detected by the illuminance sensor, the smaller the duty ratio indicating the ratio of the voltage ON time to one cycle of the voltage supplied to the illumination means. By suppressing the amount of illumination light, it is possible to extend the life of the illumination means and prevent image quality from deteriorating.

  According to the present invention, it is possible to provide an imaging apparatus capable of extending the life of the illumination unit and preventing the deterioration of the image quality.

1 is a configuration diagram of an imaging system including an imaging apparatus according to a first embodiment of the present invention. It is a figure explaining operation | movement of the imaging device which concerns on 1st Embodiment, and has shown the relationship between the output of an illumination intensity sensor, and the consumption current of a several light emitting element. It is a flowchart which shows the mode of control of the light emitting element by the illumination control part which concerns on 2nd Embodiment, and has shown the first half part. It is a flowchart which shows the mode of control of the light emitting element by the illumination control part which concerns on 2nd Embodiment, and has shown the second half part. It is a figure explaining operation | movement of the imaging device which concerns on 3rd Embodiment, and has shown the duty ratio.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following. FIG. 1 is a configuration diagram of an imaging system including an imaging apparatus according to the first embodiment of the present invention. As illustrated in FIG. 1, the imaging system 1 includes an imaging device 10 that captures a predetermined range including, for example, a driver and an occupant in a rear seat, and an in-vehicle device 20 connected to the imaging device 10.

  The imaging device 10 includes a housing 11, an imaging element (imaging unit) 12, an illumination unit (illumination unit) 13, an illuminance sensor 14, and an illumination control unit (light amount control unit) 15.

  The housing 11 accommodates the units 12 to 15 of the imaging device 10. The imaging device 12 is an infrared camera in which a lens unit is exposed in an opening 11a formed in the front center portion of the housing 11, and images a predetermined range including a driver and a passenger in a rear seat.

  The illumination unit 13 includes a plurality of light emitting elements (for example, infrared light emitting diodes) 13a to 13f, and illuminates all or part of a predetermined range imaged by the image sensor 12. The six light emitting elements 13 a to 13 f are disposed adjacent to the imaging element 12. Specifically, the first to third light emitting elements 13a to 13c are arranged side by side in the longitudinal direction of the housing 11 on one side of the imaging element 12, and the fourth to fifth light emitting elements 13d to 13f The other side of the element 12 is arranged side by side in the longitudinal direction of the housing 11.

  The illuminance sensor 14 detects ambient illuminance, and outputs a signal corresponding to the ambient illuminance to the illumination control unit 15.

  The illumination control unit 15 controls the illumination unit 13 based on a signal from the illuminance sensor 14. The illumination control unit 15 decreases the amount of illumination light from the illumination unit 13 as the illuminance detected by the illuminance sensor 14 increases.

  The in-vehicle device 20 includes a data acquisition unit 21 and a data storage unit 22. The data acquisition unit 21 is a part for inputting imaging data of the imaging device 12, and processes the input data into a storage format. The data storage unit 22 stores the data processed by the data acquisition unit 21.

  Next, the operation of the imaging apparatus 10 according to the present embodiment will be described. FIG. 2 is a diagram for explaining the operation of the imaging apparatus 10 according to the first embodiment, and shows the relationship between the output of the illuminance sensor 14 and the current consumption of the light emitting elements 13a to 13f.

  As illustrated in FIG. 2, the illumination control unit 15 decreases the value of the current supplied to each of the plurality of light emitting elements 13 a to 13 f as the illuminance detected by the illuminance sensor 14 increases.

  Specifically, when the illuminance detected by the illuminance sensor 14 is not less than the first predetermined value A and not more than the second predetermined value B, the illumination control unit 15 has a maximum current consumption for each of the plurality of light emitting elements 13a to 13f. Supply current.

  Further, when the illuminance detected by the illuminance sensor 14 exceeds the second predetermined value B and is equal to or less than the third predetermined value C, the illumination control unit 15 increases the output of the illuminance sensor 14 as the plurality of light emitting elements 13a to 13a. The current supplied to 13f is reduced proportionally.

  Furthermore, when the illuminance detected by the illuminance sensor 14 exceeds the third predetermined value C, the illumination control unit 15 blocks the current supply to the plurality of light emitting elements 13a to 13f.

  In this way, the illumination control unit 15 supplies a current to each of the plurality of light emitting elements 13a to 13f so that the maximum consumption current is obtained when brightness below a certain level is detected from the output of the illuminance sensor 14. When the light emission state is complete and brightness of a certain level or more is detected from the output of the illuminance sensor 14, the current supply to the plurality of light emitting elements 13a to 13f is cut off and the light is completely turned off.

  And between the complete light emission state and the complete extinction state, the illumination control part 15 reduces the electric current supplied to several light emitting element 13a-13f proportionally as the output of the illumination intensity sensor 14 becomes large, The light intensity is appropriate.

  Thus, according to the imaging device 10 according to the first embodiment, the light intensity of the illumination light decreases as the detected illuminance increases. Therefore, in a slightly dark environment such as evening, a predetermined range with a light quantity more than necessary is required. , It is difficult to shorten the life of the illumination unit 13, and it is also possible to prevent the predetermined range from being excessively brightened. Therefore, it is possible to extend the life of the illumination unit 13 and to prevent a reduction in image quality.

  Moreover, since the value of the electric current supplied to each of the light emitting elements 13a to 13f is reduced as the illuminance detected by the illuminance sensor 14 increases, the amount of illumination light from each of the light emitting elements 13a to 13f is suppressed, and the illumination unit Thus, the service life can be extended and the deterioration of image quality can be prevented.

  Next, a second embodiment of the present invention will be described. The imaging device 10 according to the second embodiment is the same as that of the first embodiment, but the light amount adjustment method is different from that of the first embodiment. Hereinafter, differences from the first embodiment will be described.

  First, in the second embodiment, the illumination control unit 15 reduces the number of light emitting elements 13a to 13f that emit light as the illuminance detected by the illuminance sensor 14 increases. That is, the illumination control unit 15 performs control such that, for example, four of the six light emitting elements 13a to 13f emit light and two are turned off in a slightly dark environment such as evening.

  In the second embodiment, when the illumination control unit 15 emits a predetermined number of light emitting elements 13a to 13f of one or more and not more than five (less than a plurality), the predetermined number of light emitting elements 13a to 13f emitted last time The predetermined number of the light emitting elements 13a to 13f are caused to emit light by changing at least one of them. For this reason, when the 1st-4th light emitting elements 13a-13d were light-emitting last time, the illumination control part 15 makes the 3rd-6th light emitting elements 13c-13f light-emit this time, for example.

  3 and 4 are flowcharts showing a state of control of the light emitting elements 13a to 13f by the illumination control unit 15 according to the second embodiment. In the following flowchart, a case where 0, 2, 4, and 6 of the six light emitting elements 13a to 13f are caused to emit light according to the illuminance will be described as an example. Not limited to this, control may be performed so that one, three, or five light is emitted.

  First, as shown in FIG. 3, the illumination controller 15 first causes all the light emitting elements 13a to 13f to emit light (S1). Next, the illumination control unit 15 determines whether the ambient brightness is equal to or higher than the first threshold based on the signal from the illuminance sensor 14 (S2).

  When it is determined that the surrounding brightness is equal to or higher than the first threshold (S2: YES), the illumination control unit 15 turns off all the light emitting elements 13a to 13f (S3). Then, the processing shown in FIGS. 3 and 4 ends.

  On the other hand, when it is determined that the ambient brightness is not equal to or greater than the first threshold (S2: NO), the illumination control unit 15 determines whether the ambient brightness is equal to or greater than the second threshold based on the signal from the illuminance sensor 14. (S4). Note that the second threshold is a value less than the first threshold.

  When it is determined that the ambient brightness is equal to or higher than the second threshold (S4: YES), the illumination control unit 15 determines that two of the six light emitting elements 13a to 13f are caused to emit light, and steps S5 to S9. Execute the process.

  First, the illumination control unit 15 determines whether the first to fourth light emitting elements 13a to 13d were extinguished last time (S5). When it is determined that the first to fourth light emitting elements 13a to 13d were extinguished last time (S5: YES), the illumination control unit 15 performs the first, second, fifth and sixth light emitting elements 13a, 13b, 13e, 13f is turned off (S6). Then, the processing shown in FIGS. 3 and 4 ends. In addition, the data of the light emitting elements 13a, 13b, 13e, and 13f turned off in step S6 are stored in the illumination control unit 15.

  When it is determined that the first to fourth light emitting elements 13a to 13d have not been extinguished (S5: NO), the illumination control unit 15 performs the first, second, fifth, and sixth light emitting elements 13a, 13b, It is determined whether 13e and 13f are turned off (S7).

  When it is determined that the first, second, fifth, and sixth light emitting elements 13a, 13b, 13e, and 13f were extinguished last time (S7: YES), the illumination control unit 15 selects the third to sixth light emitting elements 13c to 13f. Is turned off (S8). Then, the processing shown in FIGS. 3 and 4 ends. In addition, the data of the light emitting elements 13c to 13f turned off in step S8 are stored in the illumination control unit 15.

  On the other hand, when it is determined that the first, second, fifth, and sixth light emitting elements 13a, 13b, 13e, and 13f were not extinguished (S7: NO), the illumination control unit 15 performs the first to fourth light emission. The elements 13a to 13d are turned off (S9). Then, the processing shown in FIGS. 3 and 4 ends. In addition, the data of the light emitting elements 13a to 13d turned off in step S9 are stored in the illumination control unit 15.

  As described above, when the illumination control unit 15 causes two of the six light emitting elements 13a to 13f to emit light, the third and fourth light emitting elements 13c and 13d, the first and second light emitting elements 13a and 13b, and The fifth and sixth light emitting elements 13e and 13f are made to emit light in this order so that the specific light emitting elements 13a to 13f do not concentrate and emit light.

  By the way, when it is determined that the ambient brightness is not equal to or greater than the second threshold (S4: NO), the illumination control unit 15 determines whether the ambient brightness is equal to or greater than the third threshold based on the signal from the illuminance sensor 14. (FIG. 4: S10). Note that the third threshold is a value less than the second threshold.

  When it is determined that the ambient brightness is equal to or greater than the third threshold (S10: YES), the illumination control unit 15 determines that four of the six light emitting elements 13a to 13f are caused to emit light, and steps S11 to S15. Execute the process.

  First, the illumination control unit 15 determines whether the first and second light emitting elements 13a and 13b were extinguished last time (S11). When it is determined that the first and second light emitting elements 13a and 13b were extinguished last time (S11: YES), the illumination control unit 15 turns off the third and fourth light emitting elements 13c and 13d (S12). Then, the processing shown in FIGS. 3 and 4 ends. Note that data of the light emitting elements 13c and 13d turned off in step S12 is stored in the illumination control unit 15.

  When it is determined that the first and second light emitting elements 13a and 13b were not turned off last time (S11: NO), the illumination control unit 15 determines whether the third and fourth light emitting elements 13c and 13d were turned off last time. (S13).

  When it is determined that the third and fourth light emitting elements 13c and 13d were previously turned off (S13: YES), the illumination control unit 15 turns off the fifth and sixth light emitting elements 13e and 13f (S14). Then, the processing shown in FIGS. 3 and 4 ends. Note that data of the light emitting elements 13e and 13f turned off in step S14 is stored in the illumination control unit 15.

  On the other hand, when it is determined that the third and fourth light emitting elements 13c and 13d were not turned off last time (S13: NO), the illumination control unit 15 turns off the first and second light emitting elements 13a and 13b (S15). . Then, the processing shown in FIGS. 3 and 4 ends. Note that the data of the light emitting elements 13a and 13b turned off in step S15 is stored in the illumination control unit 15.

  As described above, when four of the six light emitting elements 13a to 13f emit light, the illumination control unit 15 performs the first, second, fifth, and sixth light emitting elements 13a, 13b, 13e, 13f, and the first. The fourth light emitting elements 13a to 13d and the third to sixth light emitting elements 13c to 13f are made to emit light in this order, so that the specific light emitting elements 13a to 13f do not concentrate and emit light.

  By the way, when it is determined that the surrounding brightness is not equal to or higher than the third threshold (S10: NO), the illumination control unit 15 does not turn off any of the light emitting elements 13a to 13f, and the processing illustrated in FIGS. finish.

  In this way, according to the imaging device 10 according to the second embodiment, as in the first embodiment, it is possible to extend the life of the illumination unit 13 and to prevent deterioration in image quality.

  In addition, according to the second embodiment, as the illuminance detected by the illuminance sensor 14 increases, the number of light emitting elements 13a to 13f to emit light decreases, so that illumination is performed by turning off some of the light emitting elements 13a to 13f. As a whole, the light amount of the unit 13 can be suppressed, the life of the illumination unit 13 can be extended, and the image quality can be prevented from being deteriorated.

  Further, when the predetermined number of light emitting elements 13a to 13f, which is one or more and less than a plurality, emit light, the predetermined number of light emitting elements 13a to 13f is different from at least one of the previously emitted predetermined number of light emitting elements 13a to 13f. In order to cause some of the light-emitting elements 13a to 13f to emit light, only the same light-emitting elements 13a to 13f are prevented from emitting light, and the light-emitting elements 13a to 13f that emit light are equalized. The lifetime of ˜13f can be extended.

  Next, a third embodiment of the present invention will be described. The imaging device 10 according to the third embodiment is the same as that of the first embodiment, but the light amount adjustment method is different from that of the first embodiment. Hereinafter, differences from the first embodiment will be described.

  First, in 3rd Embodiment, the illumination control part 15 makes small the duty ratio which shows the ratio of the ON time of the voltage with respect to 1 period of the voltage supplied to the illumination part 13, so that the illumination intensity detected by the illumination intensity sensor 14 becomes high. . That is, when the illuminance is high, the illumination control unit 15 reduces the duty ratio to reduce the light amount of each of the light emitting elements 13a to 13f as a whole.

  FIG. 5 is a diagram for explaining the operation of the imaging apparatus 10 according to the third embodiment, and shows the duty ratio. As shown in FIG. 5, the illumination control unit 15 supplies a pulsed voltage that repeatedly turns on and off to each of the light emitting elements 13a to 13f. The ratio of the ON time t that is turned on in one cycle T that repeats on / off once is the duty ratio, and the illumination control unit 15 controls the duty ratio to adjust the amount of illumination light from the illumination unit 13. Yes.

  Here, it is preferable that the frequency f (= 1 / T) of the pulse-shaped voltage which repeats ON / OFF is 60 Hz or more. This is because the flicker of the illumination unit 13 is not recognized by human eyes.

  More specifically, the illumination control unit 15 adjusts the amount of illumination light by fixing the period T and changing the length of the ON time t between 0 and T. This is because it is possible to facilitate the adjustment control of the light amount without changing the period T.

  Thus, according to the imaging device 10 according to the third embodiment, as in the first embodiment, it is possible to extend the life of the illumination unit 13 and to prevent the image quality from being deteriorated.

  Further, according to the third embodiment, as the illuminance detected by the illuminance sensor 14 increases, the duty ratio indicating the ratio of the on-time of the voltage to one cycle of the voltage supplied to the illumination unit 13 is decreased. By suppressing the amount of illumination light from the light emitting elements 13a to 13f, it is possible to extend the life of the illumination unit 13 and to prevent deterioration in image quality.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention.

  In the present embodiment, the imaging system 1 captures a predetermined range including the driver and the occupant of the rear seat. However, the imaging system 1 is not limited to this, and captures other ranges in the vehicle interior and the outside of the vehicle interior. Also good. Furthermore, it may be used not only for vehicles but also for home crime prevention.

  Moreover, although the illumination part 13 is comprised from several light emitting element 13a-13f in 1st Embodiment, it may be comprised not only with multiple but especially one light emitting element. Furthermore, in the second embodiment, the illumination unit 13 includes six light emitting elements 13a to 13f. However, the illumination unit 13 is not particularly limited to six, and includes two or more, less than five, or seven or more light emitting elements. Also good.

  In addition, although the illumination part 13 is comprised from several light emitting element 13a-13f in 3rd Embodiment, it is not restricted especially to light emitting element 13a-13f.

1: Imaging system 10: Imaging device 11: Housing 11a: Opening 12: Imaging element (imaging means)
13: Illumination parts 13a-13f: Light emitting element 14: Illuminance sensor 15: Illumination control part (light quantity control means)
20: In-vehicle device 21: Data acquisition unit 22: Data storage unit

Claims (5)

Imaging means for imaging a predetermined range;
Illuminating means for illuminating the predetermined range imaged by the imaging means;
An illuminance sensor that detects ambient illuminance;
A light amount control means for reducing the amount of illumination light from the illumination means as the illuminance detected by the illuminance sensor increases;
An imaging apparatus comprising: The illumination means is one or a plurality of light emitting elements,
The imaging apparatus according to claim 1, wherein the light amount control unit decreases a value of a current supplied to each of the light emitting elements as the illuminance detected by the illuminance sensor increases. The illuminating means is a plurality of light emitting elements,
The imaging apparatus according to claim 1, wherein the light amount control unit reduces the number of light emitting elements that emit light as the illuminance detected by the illuminance sensor increases. When the predetermined number of light emitting elements that are one or more and less than the plurality of light emitting elements emit light, the light quantity control unit makes at least one different light emitting element from the previously emitted predetermined number of light emitting elements to emit light. The imaging apparatus according to claim 3. The light amount control means reduces the duty ratio indicating the ratio of the on-time of the voltage to one cycle of the voltage supplied to the illumination means as the illuminance detected by the illuminance sensor increases. The imaging apparatus according to 1.

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