Camera System

Abstract

To provide a camera system configured to improve usability for monitoring.SOLUTION: A camera system 10 includes: a camera device 12 for acquiring video data D1 of a predetermined area; a control unit 13 which controls the camera device 12 and generates write data D2 from the input video data D1; and a write processing unit 14 which writes the write data D2 alternately on a plurality of storage media through control by the control unit 13. The control unit 13 can detect an unwritable state in which the write data D2 cannot be written on one storage medium by the write processing unit 14, and causes the camera device 12, when detecting the unwritable state, to execute data amount reduction processing to reduce the amount of the video data D1 to be output.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a camera system that is installed in a predetermined location. [Background technology]

[0002] In recent years, camera systems that are installed in predetermined locations have become known (see, for example, Patent Document 1). This camera system allows for greater freedom in installation, making it possible to monitor a variety of locations. This camera system can also record captured video onto an SD card (storage medium) inserted into an SD card slot, and the recorded video can be viewed by removing the SD card. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-19667 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above camera system, if the SD card is removed or if a situation occurs where writing to the SD card fails, the captured video cannot be recorded on the SD card, making it impossible to review the video after the fact. For this reason, the above camera system has room for improvement in terms of usability for surveillance purposes.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a camera system that can improve usability for surveillance purposes. [Means for solving the problem]

[0006] The camera system described in claim 1 comprises a camera device that acquires video data of a predetermined area, a control unit that controls the camera device and generates write data from the input video data, and a write processing unit that writes the write data alternately to multiple storage media under the control of the control unit, wherein the control unit is capable of detecting a write-disabled state in which the write processing unit cannot write the write data to any one of the storage media, and when the control unit detects the write-disabled state, causes the camera device to execute a data amount reduction process that reduces the data amount of the video data to be output. [Effects of the Invention]

[0007] The camera system of the present invention can improve usability for surveillance purposes. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an explanatory diagram showing an installation state of a camera system according to Example 1 of an embodiment of the camera system of the present invention. [Figure 2] FIG. 1 is a block diagram showing a configuration of a camera system. [Figure 3] FIG. 10 is an explanatory diagram showing how a part of an image is cut out as an example of setting 7 of the data amount reduction process by the camera system. [Figure 4] FIG. 1 is an explanatory diagram for explaining the operation of the camera system, showing a normal operation state. [Figure 5] 10 is an explanatory diagram for explaining the operation of the camera system, showing a state in which a write-disabled state is detected. FIG. [Figure 6] 10 is an explanatory diagram for explaining the operation of the camera system, showing the operation during data amount reduction processing. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a camera system according to the present invention will be described with reference to the drawings. [Example]

[0010] The schematic configuration of camera system 10 as one embodiment of the camera system according to the present invention will be described with reference to Figures 1 to 6. Figures 4 to 6 show the configuration of camera system 10 in simplified blocks, and also show how various signals and data are sent between the blocks. Figures 4 to 6 also use a light bulb design and change the lighting position on the left and right sides of lighting unit 17 to make it easier to distinguish the colors of the lit lamps in lighting unit 17.

[0011] 1 and 2, camera system 10 is configured by housing 11 and accommodating camera device 12, control unit 13, and writing processing unit 14. Housing 11 is attached to a desired installation location via mounting member 15, and in the example of FIG. 1, housing 11 is attached to the top of utility pole 16 by fastening mounting member 15. Note that the mounting method (configuration of mounting member 15) and mounting location of camera system 10 can be set as appropriate, and are not limited to the configuration of Example 1.

[0012] Housing 11 has, exposed on its bottom surface 11a, imaging unit 23, lighting unit 17, and lid unit 18 of camera device 12. As will be described later, imaging unit 23 photographs a predetermined area in camera device 12, is covered by a hemispherical transparent cover 19 provided on bottom surface 11a and faces downward, and photographs the predetermined area through cover 19.

[0013] The lighting unit 17 notifies whether the camera system 10 is in a normal state under the control of the control unit 13. In the first embodiment, a green lamp is lit if the camera system 10 is normal, and a red lamp is lit if the camera system 10 is abnormal. This allows the lighting unit 17 to check the state of the camera system 10 while the housing 11 remains attached to the installation location as described above. The camera system 10 of the first embodiment lights up the green lamp of the lighting unit 17 to indicate a normal state when two SD cards 22 (described later) are properly attached to the card mounting unit 21 and the write processing unit 14 is able to write write data D2 (see FIGS. 4 and 6 ) to each SD card 22. Furthermore, the camera system 10 of the first embodiment lights up the red lamp of the lighting unit 17 to indicate an abnormal state when one of the SD cards 22 is improperly attached to the card mounting unit 21 or when the write processing unit 14 fails to write write data D2 to each SD card 22. The lighting unit 17 may also be configured to change the color or manner (blinking, etc.) of the light depending on the state of power supply from the power source, the operating state, and the like.

[0014] The cover 18 is openable and closable, and when opened, it exposes a card mounting section 21 (see FIG. 2, etc.). The card mounting section 21 allows an SD card 22, which is an example of a recording medium, to be mounted and removed, and allows the write processing section 14 to write write data D2 to an appropriately mounted SD card 22 and read write data D2 stored in the SD card 22. The card mounting section 21 of the first embodiment allows two SD cards 22 to be mounted at the same time, and each can be removed individually. When each SD card 22 is mounted, the card mounting section 21 of the first embodiment outputs a mounting signal to the write processing section 14, indicating that each SD card 22 has been mounted individually.

[0015] Furthermore, the housing 11 of the first embodiment is provided with an external output terminal in a location covered by the lid portion 18. This external output terminal enables output of the write data D2 stored in each SD card 22, and is capable of connecting a connection cord. When the connection cord is connected to the external output terminal, the connection cord and each SD card 22 are connected via the write processing unit 14, enabling reading of the write data D2 written to each SD card 22. Note that the connection with each SD card 22 via the write processing unit 14 may be by wireless communication or may have another configuration, and is not limited to the configuration of the first embodiment.

[0016] The camera device 12 has an imaging unit 23 and an image processing unit 24. The imaging unit 23 captures an image of a predetermined area, and the image capturing area is set through a cover 19 on the bottom surface 11a. The imaging unit 23 constantly captures an image of the set area while the camera system 10 is in an operating state, and outputs a signal of the captured image to the image processing unit 24. The image processing unit 24 generates video data D1 (see FIGS. 4 and 6) based on the video signal input from the imaging unit 23 and outputs the video data D1 to the control unit 13. The image processing unit 24 is capable of setting the amount of data when outputting the video data D1 to the control unit 13. This data amount setting (Settings 1 to 7) will be described later. In the first embodiment, the camera device 12 uses a so-called network camera with an assigned IP address, and is equipped with the above-mentioned setting function. Note that the camera device 12 is not limited to the configuration of the first embodiment, as long as it has the imaging unit 23 and the image processing unit 24.

[0017] The control unit 13 is formed by a computer having a program stored in an internal memory housed in the housing 11, and comprehensively controls the operation of the camera system 10, i.e., the operation of the camera device 12 and the write processing unit 14. The control unit 13 has a data processing unit 31, a status detection unit 32, a data amount setting unit 33, and a lighting control unit 34.

[0018] When the data processing unit 31 receives the video data D1 from the image processing unit 24 of the camera device 12, it divides the video data D1 into predetermined time intervals to generate write data D2 (see FIGS. 4 and 6), and outputs the write data D2 to the write processing unit 14. The predetermined time may be set as appropriate, and in the first embodiment, it is set to 10 minutes as an example. The data processing unit 31 also generates data such as the date and time when the video data D1, which is the source of the generated write data D2, was acquired, and associates this data with the corresponding write data D2. Since this write data D2 is obtained by dividing the video data D1 into predetermined time intervals and associating the data such as the date and time, the data volume of the write data D2 is approximately the same as that of the original video data D1.

[0019] The state detection unit 32 detects whether a write-disabled state exists, in which the write processing unit 14 cannot write to one of the SD cards 22. The write-disabled state can occur when each SD card 22 is improperly inserted into the card insertion unit 21, or when the write processing unit 14 fails to write the write data D2 to each SD card 22. In the former case, each SD card 22 is removed from the card insertion unit 21 (is not inserted), or appears to be inserted into the card insertion unit 21 but is not properly inserted. In either case, an insertion signal is not output from the card insertion unit 21. In this case, as described below, the write destination setting unit 41 of the write processing unit 14 outputs an insertion-disabled signal or sets a flag based on the presence or absence of an insertion signal. If the state detection unit 32 detects the signal or flag, it determines that the write-disabled state exists; if it does not detect the signal or flag, it determines that the write-disabled state does not exist. Furthermore, as will be described later, the state detection unit 32 determines that the state is unwritable when it detects a signal indicating that writing of the write data D2 to each SD card 22 has failed from the writing unit 42 of the write processing unit 14 or a flag indicating that fact, and determines that the state is not unwritable when it cannot detect such a signal. Note that the state detection unit 32 may use any other method as long as it determines that the state is unwritable, and is not limited to the configuration of the first embodiment.

[0020] When the state detection unit 32 detects a write-disabled state, the data amount setting unit 33 outputs a data amount reduction signal S1 (see FIG. 5) to the image processing unit 24 of the camera device 12 to execute a data amount reduction process. The data amount reduction signal S1 indicates the content of the data amount reduction process, and the image processing unit 24 executes the data amount reduction process in accordance with the data amount reduction signal S1. The data amount reduction process will be described later. Note that the data amount reduction signal S1 may be a signal to execute a data amount reduction process that has been set in advance by the image processing unit 24, and is not limited to the configuration of the first embodiment.

[0021] The lighting control unit 34 controls the turning on and off of the lighting unit 17 of the housing 11. When the state detection unit 32 detects a write-disabled state, the lighting control unit 34 turns on a red lamp in the lighting unit 17 of the housing 11. Furthermore, because the lighting unit 17 is set as described above, the lighting control unit 34 turns on a green lamp in the lighting unit 17 when the state detection unit 32 does not detect a write-disabled state. Therefore, the lighting control unit 34 of the first embodiment changes the lighting of the lighting unit 17 from green to red when a write-disabled state occurs.

[0022] The write processing unit 14 writes the write data D2 output from the data processing unit 31 of the control unit 13 to two SD cards 22 that are appropriately attached to the card attachment unit 21. The write processing unit 14 has a write destination setting unit 41 and a writing unit 42. The write destination setting unit 41 sets the SD card 22 to which the writing unit 42 will write; in the first embodiment, it first sets one SD card 221 as the write destination, and when the free space on that SD card 221 runs out, it sets the other SD card 222 as the write destination. Then, when the free space on that SD card 222 runs out, the write destination setting unit 41 sets the SD card 221 as the write destination to overwrite the data, and thereafter alternately repeats the above settings.

[0023] If the write destination setting unit 41 cannot detect any of the insertion signals from the card mounting unit 21, it determines that the SD card 22 on the side where the insertion signal cannot be detected is improperly mounted.The write destination setting unit 41 then outputs a signal indicating improper mounting or sets a flag indicating this so that the status detection unit 32 can detect it, and sets only the side from which the insertion signal is being output as the write destination.When the write destination setting unit 41 detects an insertion signal for the SD card 22 (card mounting unit 21) that it has determined to be improperly mounted, it stops outputting the improper mounting signal or setting the flag, and returns to the alternate setting described above.

[0024] Furthermore, if the writing unit 42 fails to write to the set SD card 22, the write destination setting unit 41 changes the setting of the write destination and thereafter fixes the changed write destination. At that time, the write destination setting unit 41 outputs a signal indicating that the write failed or sets a flag indicating this, which can be detected by the status detection unit 32. Note that this fixation of the write destination is released when the cause of the writing failure by the writing unit 42 is resolved, and the state returns to the alternate setting state as described above, and the output of the signal or the setting of the flag is stopped. The cause of the failure can be resolved, for example, by removing the corresponding SD card 22 from the card mounting unit 21 and mounting a new, normal SD card 22 in its place.

[0025] The writing unit 42 writes the write data D2 from the data processing unit 31 to the SD card 22 set as the write destination by the write destination setting unit 41. At this time, if the write data D2 exists in the set SD card 22, the writing unit 42 overwrites the existing write data D2 with the new write data D2. Therefore, when the write data D2 from the data processing unit 31 is input, the writing unit 42 continues writing the write data D2 to each SD card 22 while changing the write destination SD card 22 in accordance with the setting of the write destination setting unit 41. This allows the writing processing unit 14 to write the write data D2 from the data processing unit 31 seamlessly to each SD card 22. If the writing by the writing unit 42 to the set SD card 22 fails (a write error), the writing processing unit 14 outputs a signal indicating this or sets a flag indicating this, so that the state detection unit 32 can detect this.

[0026] Furthermore, when a connection cord is connected to the external output terminal of the housing 11, the writing unit 42 of the first embodiment outputs the write data D2 written to each SD card 22 in response to a signal (instruction) from the connection cord. This connection may be made by wireless communication and is not limited to the configuration of the first embodiment.

[0027] Next, a description will be given of the setting of the data amount when the image processing unit 24 of the camera device 12 outputs the video data D1 to the control unit 13. The image processing unit 24 of the first embodiment can set the data amount using the following seven settings (hereinafter referred to as setting 1 to setting 7).

[0028] Setting 1 is a setting of the communication band (bandwidth). The image processing unit 24 can set the communication band (bandwidth) when outputting the video data D1 to the control unit 13. This communication band is the width of the frequency used for communication and can be expressed in units of "bps," which indicates the number of bits that can be transferred per second. Here, the camera device 12 continues to output video signals in real time from the imaging unit 23, so the image processing unit 24 continues to output the video data D1 formed by the image processing unit 24 to the control unit 13. If the communication band set for the generated video data D1 is insufficient (narrow), the image processing unit 24 outputs only the amount of video data D1 that can be transmitted within the communication band to the control unit 13, automatically not transmitting part of the video data D1. Therefore, the image processing unit 24 sets the communication band for output to the control unit 13, thereby determining an upper limit on the amount of video data D1 to be output to the control unit 13. Note that the communication band setting can be used in conjunction with Settings 2 to 7 below, and even when each setting is used, an upper limit on the amount of video data D1 to be output is determined. This communication band is set appropriately according to the settings of Settings 2 to 7 below, the processing speed of the control unit 13 and the write processing unit 14, and the length (time) of the video to be saved on both SD cards 22.

[0029] Setting 2 is a resolution setting. The image processing unit 24 is capable of setting the resolution of the video data D1 to be output to the control unit 13. This resolution is generally called pixel density, and is expressed as 1080P (1920 pixels horizontally by 1080 pixels vertically) or 720P (1280 pixels horizontally by 720 pixels vertically). The resolution is set according to the resolution (degree of density) of the video data D1 required for surveillance purposes of the camera system 10.

[0030] Setting 3 is a setting of the number of frames. The image processing unit 24 can set the number of frames in the video data D1 to be output to the control unit 13. This number of frames is the frame rate of the video, and can be expressed in units of "fps," which represents the number of frames per second. The number of frames is set according to the number of frames (smoothness of movement) of the video data D1 required for surveillance purposes of the camera system 10.

[0031] Setting 4 is a compression rate setting. The image processing unit 24 can set the compression rate for the video data D1 to be output to the control unit 13. This compression rate is the compression rate for the data of each frame of video, and does not change the size of each frame. The compression rate is set according to the image quality and length (time) of the video required for the surveillance use of the camera system 10.

[0032] Setting 5 is a setting of the interval between I frames. The image processing unit 24 is capable of setting the interval between I frames in the video data D1 that is output to the control unit 13, which is configured so that an I frame and multiple P frames are repeated. If an I frame cannot be acquired, the video based on the video data D1 will be interrupted until the next I frame is acquired. Therefore, the interval between I frames is set so that such interruptions do not cause problems when the camera system 10 is used for surveillance.

[0033] Setting 6 is a codec setting. The image processing unit 24 is capable of setting the codec of the video data D1 to be output to the control unit 13. This codec is a standard for compressing and decompressing the video data D1, and is set according to the monitoring purpose of the camera system 10. The set codec is applied to the video data D1 for which settings 2 to 5 and 7 have been set, and is set according to the monitoring purpose of the camera system 10 and the compatible standard when the video data D1 is checked afterwards.

[0034] Setting 7 is an image size setting. The image processing unit 24 can set the image size of the video data D1 to be output to the control unit 13. This image size indicates the size of each frame of a moving image. In the first embodiment, important portions for monitoring by the camera system 10 are partially cropped from the video data D1 (video data D1B (see FIG. 4, etc.)) in the basic setting described below, to obtain video data D1 (video data D1R in the reduced setting described below) with a smaller image size than the original video data D1. An example of this is shown in FIG. 3. The example in FIG. 3 shows video data D1 (video data D1B) in a case where the camera system 10 is installed to capture the user side of an ATM (automated teller machine), and shows that user M of the ATM is biased to the left side. The position of user M is determined in relation to the installation position of the operation panel on the ATM, and therefore the position of user M in the video data D1B during operation is determined in relation to the installation position of the operation panel and the camera system 10. Then, in setting 7, when it is required to reduce the data amount of video data D1B, video data D1R is generated by partially cutting out a portion of video data D1 that is likely to show user M (the portion indicated by the dashed line on the left side of FIG. 3). Note that this partial cutting out portion may be set appropriately to a portion of high importance depending on the installation location of camera system 10 and the purpose of surveillance, and is not limited to the configuration of Example 1. For example, if camera system 10 is installed on utility pole 16 as shown in FIG. 1 and used to monitor a street corner, it may be possible to cut out a portion where pedestrians are passing by but no fences or other installed objects are visible, or a portion where a person may be present but no plants are visible.

[0035] The image processing unit 24 sets the basic settings by comprehensively setting the above settings 1 to 7 in consideration of the capacities of both SD cards 22 so that one week's worth of write data D2 can be written to the two SD cards 22. Furthermore, when a data amount reduction signal S1 (see FIG. 5 ) is input from the data amount setting unit 33, the image processing unit 24 changes one or more settings from settings 1 to 7 (hereinafter also referred to as a reduced setting) in accordance with the data amount reduction signal S1. The reduced settings are determined as settings 1 to 7 so as to reduce the data amount below that of the basic setting. The image processing unit 24 reduces the data amount of video data D1 to be output to the control unit 13 in accordance with the reduced setting (hereinafter referred to as video data D1R when distinguishing between them). Therefore, the video data D1R output after the data amount reduction signal S1 is input has a smaller data amount than the video data D1 output under the basic setting (hereinafter referred to as video data D1B when distinguishing between them). As a result, the operation of the image processing unit 24 after receiving the data amount reduction signal S1 becomes the data amount reduction process. The data amount reduction process of the first embodiment is set to one or more of settings 1 to 7 so that one week's worth of write data D2 can be written to one SD card 22, that is, so that the data amount is approximately half that of the basic setting.

[0036] Next, the operation of this camera system 10 will be described with reference to Figures 4 to 6. In the following, data based on video data D1B will be referred to as write data D2B, and data based on video data D1R will be referred to as write data D2R. Furthermore, when the camera system 10 starts operating, it is assumed that the image processing unit 24 is set to the basic setting, and the write destination setting unit 41 has set the SD card 221 as the write destination.

[0037] First, when camera system 10 is powered on and starts operating, imaging section 23 in camera device 12 captures an image of a predetermined area and outputs a signal of the image to image processing section 24. As shown in Fig. 4, image processing section 24 generates video data D1B based on the video signal and outputs the video data D1B to control section 13. In control section 13, data processing section 31 generates write data D2B based on the input video data D1B and outputs the write data D2B to write processing section 14. In write processing section 14, writing section 42 writes the input write data D2B to SD card 221 set by write destination setting section 41. In camera system 10, when the free space on SD card 221 is full, write destination setting unit 41 sets SD card 222 as the write destination, and writing unit 42 writes write data D2B to SD card 222. When the free space on SD card 222 is full, write unit 42 overwrites SD card 221, and thereafter repeats alternating overwriting (see arrow A). As a result, after one week has passed since camera system 10 started operating, camera system 10 always stores the write data D2B for the past week by combining the two SD cards 22. At this time, in camera system 10, because state detection unit 32 has not detected a write-disabled state, lighting control unit 34 lights the green lamp of lighting unit 17 (in FIG. 4, the lamp on the left side of lighting unit 17 is turned on).

[0038] 5, the camera system 10 assumes that the SD card 221 has been removed from the card mounting section 21, thereby rendering the SD card 221 unwritable. The following operation is similar even when the SD card 221 is improperly mounted in the card mounting section 21, when a connection failure of the SD card 221 within the card mounting section 21 occurs due to an impact to the card mounting section 21 (camera system 10), or when the writing section 42 fails to write to the SD card 221. The write processing section 14 then causes the write destination setting section 41 to set and fix the SD card 222 as the write destination, and enables the state detection section 32 to detect that the SD card 221 is in a unwritable state. Then, in the control unit 13, the state detection unit 32 detects the unwritable state, the data amount setting unit 33 outputs a data amount reduction signal S1 to the image processing unit 24 of the camera device 12, and the lighting control unit 34 turns on the red lamp in the lighting unit 17 of the housing 11 (in FIG. 5, the lamp on the right side of the lighting unit 17 is turned on). Then, when the data amount reduction signal S1 is input, the image processing unit 24 of the camera device 12 starts the data amount reduction process as a reduction setting according to the data amount reduction signal S1.

[0039] 6, in the camera system 10, the image processing unit 24 of the camera device 12 outputs video data D1R, the amount of data of which has been reduced in accordance with the reduction setting, to the control unit 13. Based on this, the data processing unit 31 of the control unit 13 generates write data D2R and outputs it to the write processing unit 14. In the write processing unit 14, the write unit 42 writes the input write data D2R to the SD card 222 set by the write destination setting unit 41. In the camera system 10, the write destination setting unit 41 fixedly sets the SD card 222 as the write destination. Therefore, when the free space on the SD card 222 runs out, the write unit 42 overwrites the write data D2R onto the SD card 222, and repeats the above operation. Here, in the camera system 10, the write data D2R written to the SD card 222 is based on the video data D1R with the amount of data reduced as described above. Therefore, even a single SD card 222 can always store the write data D2R for the past week.

[0040] Here, regardless of whether the data volume reduction process is set or not, even if one of the two SD cards 22 attached to the card attachment portion 21 becomes unwritable, the camera system 10 can write the normal write data D2B to the other unaffected SD card 22. However, if the data volume reduction process is not set in the camera system 10, the data capacity of the storage destination will be the capacity of one SD card 22, and the time available for reviewing the video of the write data D2B afterwards will be halved.

[0041] In response to this, the camera system 10 allows two SD cards 22 to be attached to the card attachment section 21, and if one of the SD cards becomes unwritable, writes the write data D2R, the data amount of which has been reduced by a data amount reduction process, to the other SD card 22 that is not in a problematic state. In other words, if one of the SD cards becomes unwritable, the camera system 10 stores the data in the other SD card 22 that is not in a problematic state, with the memory usage rate for video per unit time reduced. Therefore, even if one of the SD cards becomes unwritable, the camera system 10 can prevent a reduction in the time during which the video of the write data D2R can be confirmed after the fact, and can maintain its surveillance function compared to when the data amount reduction process is not set.

[0042] In particular, the camera system 10 of Example 1 defines a data volume reduction process so that one week's worth of write data D2R can be written to a single SD card 22, i.e., so that the data volume is approximately half that of the basic setting. Therefore, even if one SD card 22 becomes unwritable, the camera system 10 allows the user to review a week's worth of video footage retroactively, as in normal cases, without impairing the time-saving functionality of surveillance. Additionally, the camera system 10 of Example 1 sets the data volume in the reduced setting to approximately half that of the basic setting, thereby suppressing degradation in the quality of the video footage that can be reviewed retroactively compared to when the data volume in the reduced setting is less than approximately half the data volume in the basic setting. In other words, the camera system 10 can maintain the required time for reviewing video footage retroactively in the reduced setting while minimizing the degradation in video quality required for that purpose, thereby suppressing degradation in surveillance functionality.

[0043] Furthermore, when one of the data areas becomes unwritable and the camera system 10 starts the data amount reduction process, it lights up a red lamp in the lighting section 17 of the housing 11. This allows the camera system 10 to show from the outside that one of the data areas is unwritable. This allows the user to know from the outside whether one of the data areas in the camera system 10 is unwritable or not, and also to know from the outside that the data stored there is the write data D2R.

[0044] Furthermore, in the data amount reduction process, the camera system 10 uses the functions of the camera device 12 to output the reduced data amount as video data D1R to the control unit 13. Therefore, the camera system 10 can write the reduced data amount of write data D2R to the other SD card 22 without using any special configuration.

[0045] The camera system 10 according to the first embodiment of the camera system of the present disclosure can achieve the following effects.

[0046] When the control unit 13 of the camera system 10 detects that one of the storage media (SD cards 22) is in a write-disabled state, the control unit 13 causes the camera device 12 to execute a data amount reduction process to reduce the amount of video data D1 to be output. Therefore, even if one of the SD cards 22 becomes write-disabled, the camera system 10 can write the write data D2R with a reduced amount of data to the other SD card 22 that is not in a write-disabled state, and can prevent a reduction in the time during which the video of the write data D2R can be checked afterwards.

[0047] In the data amount reduction process, the camera device 12 of the camera system 10 reduces the amount of video data D1 to be output in proportion to the data capacity of the storage medium (SD card 22) that is not in a write-disabled state relative to the data capacity of all storage media (SD cards 22). Therefore, even if one of the SD cards 22 becomes write-disabled, the camera system 10 can make the video time of the write data D2R that can be checked after the fact equal to that when the SD card is not in a write-disabled state, and can keep the degradation of video quality to a minimum required for this, thereby suppressing degradation of the surveillance function.

[0048] In camera system 10, image processing unit 24, which generates video data D1 based on a video signal from imaging unit 23 in camera device 12 and outputs the generated video data D1 to control unit 13, reduces the amount of video data D1 to be output in a data amount reduction process. Therefore, camera system 10 can reduce the amount of video data D1 to be output using basic functions of image processing unit 24, and this can be achieved without using any special configuration.

[0049] In camera system 10, improper installation of storage medium (SD card 22) in the installation section (card installation section 21) is treated as a write-disabled state. Therefore, even if the storage medium is removed to check the video afterwards, if the storage medium is not properly installed in the installation section, or if a connection failure of the storage medium within the installation section occurs due to an impact to the installation section (camera system 10), the camera system 10 can prevent a reduction in the time during which the video can be checked afterwards.

[0050] The camera system 10 defines a state in which writing to the storage medium (SD card 22) by the write processing unit 14 has failed as a write-disabled state. Therefore, even if an unexpected malfunction occurs in one of the mounting units (card mounting unit 21) or the storage medium, the camera system 10 can prevent a reduction in the time during which the video can be checked after the fact.

[0051] When the control unit 13 detects a write-disabled state, the camera system 10 lights up the lighting unit 17. Therefore, the camera system 10 allows the user to know from the outside whether the camera system 10 is in a write-disabled state or not, and also allows the user to know from the outside that the data stored there is the write data D2R.

[0052] In camera system 10, camera device 12 outputs video data D1 to control unit 13 while reducing the communication bandwidth to control unit 13 during data amount reduction processing. Therefore, camera system 10 can appropriately reduce the amount of write data D2R output to write processing unit 14 regardless of the data amount of video data D1 generated by camera device 12, and can suppress a reduction in the time available for checking the video afterwards.

[0053] In camera system 10, camera device 12 generates video data D1 with a reduced data amount compared to before the detection of the write-disabled state in the data amount reduction process. Therefore, camera system 10 can reduce the data amount of video data D1 itself generated by camera device 12, and therefore can appropriately reduce the data amount of write data D2R output to write processing unit 14, thereby preventing a reduction in the time available for checking the video afterwards.

[0054] Therefore, the camera system 10 of the present invention can check the video after the fact even if one of the SD cards 22 serving as storage media is removed or if writing to one of the SD cards 22 becomes impossible, thereby improving usability for surveillance purposes.

[0055] The camera system of the present disclosure has been described above based on each embodiment, but the specific configuration is not limited to each embodiment, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims.

[0056] For example, in the first embodiment, the camera system 10 is attached to the top of the utility pole 16 and used for monitoring street corners for crime prevention. However, the camera system 10 can be used for various purposes and places, and is not limited to the first embodiment, as long as it stores images for a predetermined period of time for later confirmation of the images and allows the storage medium (SD card 22) to be removed for such confirmation.

[0057] 2 and other figures, the control unit 13 and the write processing unit 14 are configured as separate blocks. However, the control unit 13 and the write processing unit 14 may be configured as an integrated unit, and are not limited to the configuration of the first embodiment.

[0058] Furthermore, in the first embodiment, two SD cards 22 are used as storage media. However, the number and type (configuration) of the storage media may be set appropriately as long as they are detachable from the mounting portion (card mounting portion 21) and allow subsequent confirmation of the video while allowing writing of the write data D2B in the normal state (basic setting) and the write data D2R in the write-disabled state (reduced setting), and are not limited to the configuration of the first embodiment. Here, when three or more storage media (SD cards 22) are used, the data amount reduction process may be executed as described above when at least one storage medium is normal (not in a write-disabled state) and the rest are in a write-disabled state. Even in this case, in the camera system 10, it is preferable that the camera device 12 reduces the data amount of the video data D1 to be output in accordance with the ratio of the data capacity of the storage medium (SD card 22) that is not in a write-disabled state to the data capacity of all the storage media (SD cards 22) in the data amount reduction process.

[0059] In the first embodiment, when the free space on one SD card 22 runs out, the write processing unit 14 switches writing to the two SD cards 22 (storage media) to the other SD card 22. However, as long as the write processing unit 14 alternates writing to the multiple SD cards 22 (storage media), the write processing unit 14 may switch at a predetermined time, switch by date, or switch at another timing, regardless of the free space on the SD cards 22, and is not limited to the configuration of the first embodiment. [Explanation of symbols]

[0060] 10 camera system 12 camera device 13 control unit 14 write processing unit 17 lighting unit 21 card mounting unit (as an example of a mounting unit) 22 SD card (as an example of a storage medium) 23 imaging unit 24 image processing unit D1 video data D2 write data

Claims

1. a camera device that acquires video data of a predetermined area; a control unit that controls the camera device and generates writing data from the input video data; a write processing unit that writes the write data alternately to a plurality of storage media under the control of the control unit, The control unit is capable of detecting a write-disabled state in which the write processing unit cannot write the write data to any one of the storage media, and when the write-disabled state is detected, causes the camera device to execute a data volume reduction process that reduces the data volume of the video data to be output by the proportion of the data capacity of the storage medium that is not in the write-disabled state to the data capacity of all the storage media.

2. the camera device includes an imaging unit that captures an image of a predetermined area, and an image processing unit that generates the video data based on a signal from the imaging unit and outputs the video data to the control unit; 2. The camera system according to claim 1, wherein the image processing unit reduces the amount of the video data to be output in the data amount reduction process.

3. Furthermore, the storage medium has a detachable mounting portion, 3. The camera system according to claim 1, wherein the write-disabled state is a state in which the storage medium is improperly attached to the attachment portion.

4. A camera system as described in claim 1 or claim 2, characterized in that the unwritable state is a state in which the write processing unit has failed to write to the storage medium.

5. Further, a lighting unit that is turned on and off under the control of the control unit, 5. The camera system according to claim 1, wherein the control unit turns on the lighting unit when detecting the write-disabled state.

6. A camera system described in any one of claims 1 to 5, characterized in that, during the data volume reduction process, the camera device outputs the video data to the control unit while reducing the communication bandwidth to the control unit.

7. 7. The camera system according to claim 1, wherein the camera device generates the write data with a reduced data amount compared to before the detection of the write-disabled state in the data amount reduction process.

Images