JP2008111886A - Automatic door, screen display apparatus, screen display control program, and computer readable recording medium recorded with the program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen display apparatus capable of effectively preventing the sticking of a display and reducing power consumption by performing a screen display with a simple configuration only when necessary for a user. <P>SOLUTION: A programmable display unit 2 includes a face detection part 211 and a screen control part 212. The face detection part 211 detects presence of a front face of a person in a video of a camera 6, and when the presence of the person's front face is not detected for a predetermined time, the screen control part 212 switches off back-light 25. Further, when the face detection part 211 detects the person's front face, and judges that the distance between the face and a display 22 is shorter than a predetermined distance and the position of the face is one and the same for a predetermined time, the screen control part 212 switches on the back-light 25 again. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automatic door provided with a face detection means for detecting a face in front of a person and a screen display device.

  Conventionally, in the field of screen display, screen saver technology has been widely used in screen display devices in order to prevent display burn-in. The screen saver technique is a technique for displaying a screen saver screen on a display when the user does not operate the operation screen for a certain period of time while the power is turned on.

  Furthermore, various devices have been proposed for setting the time until the screen saver screen is displayed on the display from the viewpoint of reducing power consumption and preventing burn-in of the display. For example, in Patent Document 1, the presence of an operator in front of a display device is detected by an operator sensor, and the state of the display screen is detected. When there is no operator and the display screen does not change for a certain period of time, Discloses a configuration for displaying a screen saver screen. Thus, even if the operator does not operate the display device, the screen saver screen is not switched if the operator exists in front of the display device.

In the field of automatic doors, an automatic door using a human sensor opens the door even when a person passes in front of the door. In order to prevent such unnecessary opening and closing of the door, instead of using a human sensor, a technology is widely used in which a touch switch is provided on the door knob and the door is opened by touching the touch switch. (For example, patent document 2).
Japanese Patent Laid-Open No. 9-50258 (published on February 18, 1997) Japanese Patent Laid-Open No. 5-33552 (published on February 9, 1993)

  However, the configuration of Patent Document 1 has a problem that a normal screen is displayed on the display even when the operator is not looking at the screen. Specifically, even if the operator exists in front of the display device, the screen continues to be displayed if the operator does not look at the screen of the display device, such as performing operations other than operations on the display device. Therefore, it is impossible to effectively prevent display burn-in. In addition, since an operator sensor is used, a dedicated control device for controlling the operator sensor is required in addition to the operator sensor. Accordingly, there is a problem that the display device with restrictions on hardware resources is expensive.

  Moreover, in the structure of patent document 2, when it is difficult to touch-operate a door knob for some reason, there exists a problem that it is difficult to pass an automatic door.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to effectively prevent display burn-in by performing screen display only when a user needs with a simple configuration. It is to realize a screen display device and to realize an automatic door that does not open an unnecessary door without using a human sensor or a touch switch.

  In order to solve the above problems, a screen display device according to the present invention is a screen display device that displays a screen on a display, and the face of a person's front face is displayed in an image of a camera that captures the front of the display. A face detecting means for detecting presence, and a screen control means for displaying a screen saver screen on the display when the face detecting means does not detect the presence of a face in front of a person for a predetermined time. It is said.

  According to the above configuration, when the state in which the face detection unit does not detect the presence of the face in front of the person continues for a predetermined time, the screen saver screen is displayed on the display, so that the user exists in front of the screen display device. However, when the display is not viewed for a predetermined time, a screen saver screen is displayed. On the other hand, if the user looks at the display even if no operation is performed, the screen saver screen is not unexpectedly displayed.

  In general, since the screen display device has a standard interface corresponding to the camera, it is not necessary to add an image capturing device. Furthermore, even when the screen display device is provided with a camera for another purpose, the camera can be used for the purpose of detecting the presence of the front face. Therefore, the number of parts can be reduced and the cost can be reduced as compared with a configuration including a human sensor that needs a separate dedicated control device for controlling the human sensor.

  Therefore, it is possible to realize a screen display device that effectively prevents display burn-in by performing screen display only when the user needs with a simple configuration.

  In the screen display device according to the present invention, it is preferable that the screen control means cancels the display of the screen saver screen when the face detection means detects the presence of a face in front of a person.

  According to the above configuration, the face detection means does not cancel the display of the screen saver screen unless the presence of the face in front of the person is detected, so the screen saver screen is canceled only by the person passing in front of the screen display device. Not. Therefore, the burn-in of the display can be more effectively prevented.

  In the screen display device according to the present invention, the screen control means detects the presence of a face in front of a person and determines that the distance between the face and the display is shorter than a predetermined distance. It is preferable to cancel the display of the screen.

  According to the above configuration, the face detection means not only detects the presence of the face in front of the person but also does not cancel the display of the screen saver screen unless it is determined that the distance between the face and the display is shorter than a predetermined distance. Therefore, just by looking at the display from a distance, the screen saver screen is not released. Therefore, the burn-in of the display can be more effectively prevented.

  In the screen display device according to the present invention, the screen control means detects the presence of a face in front of a person, and the distance between the face and the display is shorter than a predetermined distance, and the position of the face is detected. Are determined to be the same for a predetermined time, it is preferable to cancel the display of the screen saver screen.

  According to the above configuration, the face detection means not only detects the presence of a face in front of a person and determines that the distance between the face and the display is shorter than a predetermined distance, but also the position of the face is determined for a predetermined time. Unless the screen saver screen is determined to be the same, the screen saver screen display is not canceled. Therefore, the screen saver screen is not canceled only by a person who passes near the screen display device instantaneously sees the display. Therefore, the burn-in of the display can be more effectively prevented.

  A screen display device according to the present invention is a screen display device that displays a screen on a display having a backlight, and detects the presence of a face in front of a person in an image of a camera that captures the front of the display. And a screen control unit that turns off the backlight when a state in which the face detection unit does not detect the presence of a face in front of a person continues for a predetermined time.

  According to the above configuration, when the state in which the face detection unit does not detect the presence of the face in front of the person continues for a predetermined time, the backlight is turned off, so even if the user is present in front of the screen display device, the display Is not displayed on the display for a predetermined time, the screen is not displayed on the display. On the other hand, if the user looks at the display even when no operation is performed, the display on the screen is not unexpectedly erased. In addition, since it is a configuration that only installs a camera without the need for a human sensor, the screen is displayed only when the user needs it with a simple configuration, thereby effectively preventing display burn-in and further wastefulness. It is possible to realize a screen display device that does not consume a large amount of power.

  In the screen display device according to the present invention, it is preferable that the screen control means turns on the backlight when the face detection means detects the presence of a face in front of a person.

  According to the above configuration, the face detection means does not turn on the backlight unless the presence of the face in front of the person is detected. Therefore, if the person simply passes in front of the screen display device, the screen is displayed on the display. Do not show. Therefore, it is possible to more effectively prevent display burn-in and reduce power consumption.

  In the screen display device according to the present invention, the screen control means detects the presence of a face in front of a person and determines that the distance between the face and the display is shorter than a predetermined distance. It is preferable to turn on the backlight.

  According to the above configuration, the face detection means not only detects the presence of the face in front of the person but also does not turn on the backlight unless it is determined that the distance between the face and the display is shorter than a predetermined distance. If a person only looks at the display from a distance, the screen does not appear on the display. Therefore, it is possible to more effectively prevent display burn-in and reduce power consumption.

  In the screen display device according to the present invention, the screen control means detects the presence of a face in front of a person, and the distance between the face and the display is shorter than a predetermined distance, and the position of the face is detected. Are determined to be the same for a predetermined time, it is preferable to turn on the backlight.

  According to the above configuration, the face detection means not only detects the presence of a face in front of a person and determines that the distance between the face and the display is shorter than a predetermined distance, but also the position of the face is determined for a predetermined time. Unless the backlights are determined to be the same, the backlight is not turned on. Therefore, if a person passing near the screen display device instantaneously sees the display, the screen is not displayed on the display. Therefore, it is possible to more effectively prevent display burn-in and reduce power consumption.

  In the screen display device according to the present invention, the face detection unit is configured to detect the human face when a predetermined facial part is detected from among the eyes, the nose, the mouth, the eyebrows, and the ears from the human face of the camera image. Is preferably a front face.

  According to the above configuration, even when the entire face is not shown in the video of the camera, the face detection unit can objectively determine whether or not it is a front face.

  In the screen display device according to the present invention, the face detection means detects face parts detection means for detecting two or more face parts among eyes, nose, mouth, eyebrows and contours from the human face of the camera image; Of the detected face parts, in the combination of two face parts, the slope calculation for calculating the slope indicating the deviation of the relative positions of the face parts of each combination from the relative positions of the face parts in the frontal face. When the slope of at least one combination of the means and the selected combination is within a predetermined range, and the front index set in advance for the combination is greater than or equal to a reference value, It is preferable to have a front face determination unit that determines that the human face is a front face. Further, in the screen display device according to the present invention, the front face determination means sums the front indices of each selected combination when the front indices of any combination of the selected combinations is less than the reference value. And when the said total value is more than the said reference value, it is preferable to determine with the said human face being a front face.

  According to said structure, the face detection means can detect the inclination degree of the face from the front, and can determine more accurately whether it is a front face.

  In the screen display control program according to the present invention, a computer is caused to function as the face detection means and the screen control means. The screen display control program is provided by being recorded on a computer-readable recording medium. Thereby, it is possible to realize a screen display device that can effectively prevent display burn-in by performing screen display only when the user needs with a simple configuration.

  The automatic door according to the present invention is an automatic door that automatically opens and closes the door. Face detecting means for detecting the presence of a face in front of a person in a video of a camera that captures the front of the automatic door; and When the face detecting means detects the presence of a face in front of a person, the door detecting means is provided to open the door for a predetermined time.

  According to the above configuration, the door is opened when the face of the person is present in the image of the camera. Therefore, the door is not opened only by passing the person in front of the automatic door. Therefore, there is an effect that it is possible to realize an automatic door that does not open an unnecessary door without using a human sensor or a touch switch.

  In the automatic door according to the present invention, the door control means detects the presence of a face in front of a person and determines that the distance between the face and the door is shorter than a predetermined distance. Is preferably opened for a predetermined time.

  According to the above configuration, the face detection means not only detects the presence of the face in front of a person, but also determines that the distance between the face and the display is shorter than a predetermined distance, the door control means opens the door. Therefore, the door is not opened only by looking at the door from a distance. Therefore, unnecessary opening of the door can be prevented.

  In the automatic door according to the present invention, the door control means detects the presence of the face in front of the person by the face detection means, the distance between the face and the door is shorter than a predetermined distance, and the position of the face is If it is determined that they are the same for a predetermined time, the door is preferably opened for a predetermined time.

  According to the above configuration, according to the above configuration, the face detection means not only detects the presence of the face in front of the person and determines that the distance between the face and the display is shorter than a predetermined distance, Unless the face positions are determined to be the same for a predetermined time, the door control means does not open the door. Therefore, the person who passes near the automatic door does not open the door only by looking at the door instantaneously. Therefore, unnecessary opening of the door can be prevented.

  In the automatic door according to the present invention, the face detection means detects the human face when a predetermined facial part is detected among the eyes, nose, mouth, eyebrows and ears from the human face of the camera image. It is preferable to determine that the face is a front face.

  According to the above configuration, even when the entire face is not shown in the video of the camera, the face detection unit can objectively determine whether or not it is a front face.

  In the automatic door according to the present invention, the face detection means includes a face part detection means for detecting two or more face parts among eyes, nose, mouth, eyebrows and contours from the human face of the camera image; In the combination of two face parts, the inclination degree calculating means for calculating the inclination degree indicating the deviation of the relative position of the face parts of each combination from the relative position of the face parts in the front face in the combination of the two face parts And when the slope of at least one of the selected combinations is within a predetermined range and the front index preset for the combination is greater than or equal to a reference value, the person It is preferable to have front face determination means for determining that the face is a front face. Further, in the automatic door according to the present invention, the front face determination means sums the front indices of each selected combination when the front indices of any combination among the selected combinations are less than the reference value. When the total value is greater than or equal to the reference value, it is preferable to determine that the human face is a front face.

  According to said structure, the face detection means can detect the inclination degree of the face from the front, and can determine more accurately whether it is a front face.

  A screen display device according to the present invention includes a face detection unit that detects the presence of a face in front of a person in a video image of a camera that captures the front of the display, and the face detection unit detects the presence of a face in front of a person. Since the screen control means for displaying the screen saver screen on the display when the non-detection state continues for a predetermined time, the screen is displayed only when necessary by a user with a simple configuration, so that the display is burned. There is an effect that it is possible to realize a screen display device that is effectively prevented.

  The automatic door according to the present invention includes a face detection unit that detects the presence of a face in front of a person in a video image of a camera that photographs the front of the automatic door, and the face detection unit Since it is provided with door control means for opening the door for a predetermined time when the presence is detected, it is possible to realize an automatic door that does not open an unnecessary door without using a human sensor or a touch switch. There is an effect.

[Embodiment 1]
One embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a block diagram of a control system 1 including a programmable display 2 (screen display device) according to the present embodiment. The control system 1 includes a programmable display 2 and a programmable logic controller (PLC) 3 and controls a device 4 connected to the PLC 3.

  The programmable display device 2 includes a control unit 21, a display 22, a memory unit 23, a touch panel 24, a backlight 25, and interface units (displayed as “I / F” in the drawing) 26 and 27.

  As the display 22, a flat panel display such as a liquid crystal display is preferably used in order to configure the programmable display device 2 to be thin. The memory unit 23 stores user screen data indicating the operating status of the device 4. The user screen is displayed on the display 22 by reading necessary data.

  The control unit 21 performs processing such as display control of the user screen, control of input operation via the user screen, and control of communication with a connected device such as the PLC 3. The control unit 21 includes a face detection unit 211 and a screen control unit 212. The face detection unit 211 and the screen control unit 212 are functional blocks for realizing a screen display control function described later.

  The touch panel 24 is an input device provided for performing input on the display screen of the display 22. The backlight 25 is a light source for irradiating light from the back surface of the display 22 in order to display a user screen on the display 22. The interface unit 26 is a communication control unit for the programmable display 2 to perform serial communication with the PLC 3, and is connected to the serial cable 5. Thus, the user can control the device 4 via the PLC 3 by performing a touch operation on the touch panel 24 while viewing the user screen displayed on the display 22.

  A camera 6 is installed at the peripheral edge of the display 22. The camera 6 is directed to the front of the programmable display 2 so that the user's face existing in front of the programmable display 2 can be photographed. The programmable display device 2 and the camera 6 are connected via the interface unit 27, and image data from the camera 6 is sent to the face detection unit 211.

  The face detection unit 211 analyzes image data from the camera 6 and detects the presence of a face in front of a person in the image of the camera 6. When the face detection unit 211 detects a face in front of a person, the screen control unit 212 turns on the backlight 25. On the other hand, when the backlight is on and the face detection unit 211 does not detect the face in front of the person for a predetermined time, the screen control unit 212 turns off the backlight 25.

  FIG. 2 is a front view of the programmable display 2, and the camera 6 is provided on the outer frame directly above the center of the display 22. FIG. 2A shows a state in which the backlight 25 shown in FIG. 1 is ON, and a user screen is displayed on the display 22 of the programmable display device 2. On the other hand, FIG. 2B shows a state in which the backlight 25 is OFF, and the user screen is not displayed on the display 22.

  Next, the screen display control function realized by the face detection unit 211 and the screen control unit 212 will be specifically described with reference to FIGS. 3 and 4.

  FIG. 3 is a flowchart of the screen display control function. The face detection unit 211 analyzes the image data sent from the camera 6 while the programmable display 2 is activated, and detects whether or not a face in front of a person exists. When the backlight 25 is on (step S1) and the face detection unit 211 detects a face in front of a person, the screen control unit 212 keeps the backlight 25 on (in step S2). "YES"). When the face detection unit 211 does not detect the face in front of the person (“NO” in step S2), the screen control unit 212 determines that the predetermined time has elapsed after the face detection unit 211 no longer detects the face in front of the person. It is determined whether or not it has elapsed (step S3). When the predetermined time has elapsed (“YES” in step S3), the screen control unit 212 turns off the backlight 25 (step S4).

  Thus, when the user is not looking at the display 22, the camera 6 does not detect the face in front of the user, and thus the screen is not displayed on the display 22 after a predetermined time has elapsed. On the other hand, even if the user does not operate the programmable display device 2, the screen display will not disappear unexpectedly if the display 22 is viewed.

  On the other hand, even if the user exists in front of the programmable display 2, the screen display disappears when the user does not look at the display 22 for a predetermined time, for example, by performing work other than the operation on the programmable display 2. Therefore, the screen 22 is not unnecessarily displayed on the display 22, the burn-in of the display 22 can be prevented, and the power consumption of the programmable display device 2 can be reduced.

  Subsequently, when the backlight 25 is OFF (step S4) and the face detection unit 211 detects a face in front of a person (“YES” in step S5), the face detection unit 211 determines whether the face and the display 22 It is determined whether or not the distance is within a predetermined distance (step S6). When the distance between the face and the display 22 is within the predetermined distance (“YES” in step S6), the face detection unit 211 further determines whether the face positions are the same for a predetermined time (step S7). . When the face positions are the same for a predetermined time (“YES” in step S7), the screen control unit 212 turns on the backlight 25 again (step S8).

  As a result, if a person passing near the programmable display device 2 instantaneously sees the display 22, the screen is not displayed on the display 22. In addition, since the screen is displayed on the display 22 by viewing the display 22 from the vicinity of the programmable display device 2 for a predetermined time, even a person who has a baggage in both hands can operate the device without touching the touch panel 24. 4 or the like can be confirmed.

  In the programmable display device 2, the screen control unit 212 may be configured to display / hide the screen saver screen on the display 22 instead of controlling the backlight OFF / ON as described above.

  FIG. 4 is a flowchart according to a modification of the screen display control function. The face detection unit 211 analyzes the image data sent from the camera 6 while the programmable display 2 is activated, and detects whether or not a face in front of a person exists. When the normal screen is displayed on the display 22 (step S11), when the face detection unit 211 detects a face in front of a person, the screen control unit 212 displays the normal screen on the display 22. This state is maintained (“YES” in step S2). When the face detection unit 211 does not detect the face in front of the person (“NO” in step S2), the screen control unit 212 determines that the predetermined time has elapsed after the face detection unit 211 no longer detects the face in front of the person. It is determined whether or not it has elapsed (step S3). When the predetermined time has elapsed (“YES” in step S3), the screen control unit 212 displays a screen saver screen on the display 22 (step S4). The display of the screen saver screen is performed by storing protection screen data for the screen saver screen in advance in the memory unit 23 and reading out the protection screen data by the screen control unit 212.

  Accordingly, when the user is not looking at the display 22, the camera 6 does not detect the face in front of the user, and thus a screen saver screen is displayed on the display 22 after a predetermined time has elapsed. On the other hand, even if the user does not operate the programmable display device 2, if the user is looking at the display 22, the screen saver screen is not unexpectedly switched.

  On the other hand, even if the user is present in front of the programmable display 2, when the user does not look at the display 22 for a predetermined time, for example, by performing work other than the operation on the programmable display 2, a screen saver is displayed on the display 22. A screen is displayed. Therefore, the screen 22 is not unnecessarily displayed on the display 22 and the burn-in of the display 22 can be prevented.

  In addition, in the state where the backlight 25 is OFF, it cannot be distinguished whether or not the programmable display 2 is powered on. In that respect, if the screen saver screen is displayed, it can be easily determined that the programmable display 2 is turned on.

  Subsequently, when the screen saver screen is displayed on the display 22 (step S14), when the face detection unit 211 detects a face in front of a person (“YES” in step S15), the face detection unit 211 It is determined whether the distance between the display 22 and the display 22 is within a predetermined distance (step S16). When the distance between the face and the display 22 is within a predetermined distance (“YES” in step S16), the face detection unit 211 further determines whether the face positions are the same for a predetermined time (step S17). . If the face positions are the same for a predetermined time (“YES” in step S17), the screen control unit 212 cancels the display of the screen saver screen and displays the normal screen on the display 22 again (step S18).

  Thereby, the display of the screen saver screen is not canceled only by a person who passes near the programmable display device 2 instantaneously looks at the display 22. In addition, since a normal screen is displayed on the display 22 by looking at the display 22 for a predetermined time from the vicinity of the programmable display device 2, even a person holding a baggage in both hands does not perform a touch operation on the touch panel 24. The state of the device 4 can be confirmed.

  Note that the screen display control function according to the present embodiment is realized by causing a computer to execute a screen display control program. The screen display control program can also be recorded on a recording medium configured to be separable from the computer, and may be installed in the computer from the recording medium.

  Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, and disks including optical disks such as CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

[Embodiment 2]
Another embodiment of the present invention will be described below with reference to FIGS.

  FIG. 5 is a block diagram of the automatic door 10 according to the present embodiment. The automatic door 10 includes a door 11, a door engine 12, a door engine control unit 13, a face detection unit 14, and an interface unit (indicated as “I / F” in the figure) 15. 16 is connected to the face detection unit 14.

  FIG. 6 is a front view of the automatic door 10, and the camera 16 is provided above the middle point of the two doors 11. The camera 16 is directed to the front of the automatic door 10 so that a face of a passerby existing in front of the automatic door 10 can be photographed. Image data from the camera 16 is sent to the face detection unit 14.

  The face detection unit 14 analyzes the image data from the camera 16 and detects whether a face in front of a person exists in the image of the camera 16. As shown in FIG. 6, when a passerby who is willing to pass through the automatic door 10 proceeds toward the door 11, the face detection unit 14 detects the front face of the passerby. In this case, the face detection unit 14 sends a command to the door engine control unit 13 to open the door 11, and the door engine control unit 13 drives the door engine 12 to open the door 11 for a predetermined time.

  On the other hand, as shown in FIG. 7A, when a passerby passes in front of the automatic door 10, the camera 16 does not detect the front face of the passerby. Therefore, the door 11 is not opened, and the door 11 is not unnecessarily opened.

  Further, as shown in FIG. 7B, the camera 16 does not detect the front face of the passer-by when the passer-by in front of the automatic door 10 is wearing a helmet or the like. Therefore, the door 11 is not opened, and intrusion of a suspicious person or the like can be prevented.

[Embodiment 3]
Next, how the face detection unit 211 in the first embodiment and the face detection unit 14 in the second embodiment detect a person's front face will be described in more detail.

  The determination of whether or not the face is a front face in the present embodiment is divided into determination based on face component detection and determination based on the positional relationship of the detected components, which are used depending on the application.

  First, determination by detection of a facial part will be described. Specifically, the face detection unit 211 and the face detection unit 14 are configured as a face detection unit 100 illustrated in FIG. The face detection unit 100 includes a face part detection unit 101 and a front determination unit 102.

  The face part detection unit 101 detects each part of the face (eyes, nose, mouth, eyebrows, ears, etc.) using a known method.

  The front determination unit 102 refers to the front index table 103 for the facial parts detected by the facial part detection unit 101, and sums the front indices used for the determination among the front indices set in advance for each part of the face. Then, by comparing the total value with the front face determination reference value, it is determined whether or not it is a front face. Table 1 shows an example of the front index table 103. The front index table 103 sets face parts, detection criteria, front indices, and used / unused in association with each other. For example, in the programmable display 2, the front index table 103 is stored in the memory unit 23.

  The detection criterion is a criterion for determining whether or not each part of the face has been detected. For example, in the case of detecting eyes, it is determined that eyes are detected only when both eyes are detected, and only one eye is detected. If so, it is not determined that eye detection has been performed. The nose is detected only when the central part of the nose is detected. When only a part other than the central part of the nose is detected, it is not determined that the nose is detected. .

  The front index is a numerical value of the weight of the detected face part with respect to the front face determination criterion.

  Use / unused indicates whether or not the front index of the detected face part is used for front face determination.

  The front determination unit 102 determines whether or not each part of the face has been detected according to the above detection criterion, and sums up the front indices of the detected parts. For example, when eyes and eyebrows are detected, the total value of the front index is calculated as 90. The total value is compared with a predetermined determination reference value, and if it is equal to or greater than the determination reference value, it is determined that the face is a front face.

  The determination reference value is set to 80, for example, and when eyes and eyebrows are detected, the total value of the front index is equal to or greater than the determination reference value, so that it is determined to be a front face. On the other hand, when only the nose and the mouth are detected, the total value of the front index is 40, which is less than the determination reference value, and thus is not determined to be a front face.

  The determination reference value is variously set according to the environment in which it is used. For example, when the front face determination is used to determine whether or not the display 22 is viewed as in the first embodiment, the determination reference value is set high. On the other hand, as in the second embodiment, when the determination of the front face is used for determining whether or not there is an intention to pass through the automatic door 10, the determination reference value is set low.

  Also, in an environment such as a factory where the programmable display 2 is used, a mask and a hat are worn, so the mouth, nose and ears are often hidden. Therefore, even if the mouth, nose, and ear are detected, the front index of those facial parts can be set not to be used.

  Next, determination based on the positional relationship of the detection components will be described with reference to FIGS. This determination can detect the degree of inclination of the face from right to left, which cannot be determined by the above-described determination based on face component detection, and enables more accurate determination of whether or not the face is a front face.

  Specifically, the face detection unit 211 and the face detection unit 14 are configured as a face detection unit 110 illustrated in FIG. 9. The face detection unit 110 includes a face part detection unit 111, an inclination calculation unit 112, and a front determination unit 113.

  The face part detection unit 111 detects each part of the face (eyes, nose, mouth, eyebrows, ears, contours, etc.) using a known method as described above.

  The inclination calculation unit 112 determines whether or not each part of the face has been detected, and calculates an inclination described later from the relative position in the detected combination of face parts. A method of calculating the inclination by the inclination calculating unit 112 will be described in detail later with reference to FIGS.

  The front determination unit 113 refers to the front index table 114, and determines whether the face satisfies the front face determination criterion when the inclination calculated by the inclination calculation unit 112 is within the detection reference range. It is determined whether or not it is the front. The front face determination by the front determination unit 113 will be described in detail later with reference to the flowchart shown in FIG.

  As shown in Table 2, the front index table 114 sets two types of face parts for calculating a relative position, an inclination, a detection reference, a front index, and used / unused in association with each other. . For example, in the programmable display device 2, the front index table 114 is stored in the memory unit 23.

  The degree of inclination is a numerical value indicating the degree of inclination of the face from the front to the left and right, and a specific calculation method will be described later.

  The detection criterion is a criterion for determining whether or not a combination of each part of the face has been detected. For example, the detection of eyebrows and nose is performed when the slope Sbn calculated by the calculation formula described later is within ± 10%. Determines that eyebrows and nose have been detected, and does not determine that eyebrows and nose have been detected if the slope Sbn is less than −10% or exceeds 10%.

  The front index is a numerical value of the weight of the detected combination of face parts for the front face determination criterion.

  Use / unused indicates whether or not the front index of the detected face part is used for front face determination.

  Here, the determination procedure based on the positional relationship of the detection components will be described with reference to FIG.

  FIG. 10 is a flowchart of determination based on the positional relationship of the detection components. First, as in the case of the above-described determination by facial component detection, the facial component detection unit 111 detects facial components (eyes, nose, mouth, eyebrows, ears, contours) (step S21). Subsequently, the inclination calculating unit 112 calculates the inclination for each combination of detected components (step S22). Subsequently, the front face determination unit 113 determines whether or not the inclination of the combination of face parts set to be used in the front index table 114 satisfies the detection criterion (step S23). If there is a combination that satisfies the detection criterion (“YES” in step S23), the front face determination unit 113 further determines whether or not the front index to be used satisfies a preset front face determination criterion (step S23). S24). If the front index satisfies the front face determination criterion (“YES” in step S24), the front face determination unit 113 determines that it is a front face (step S25), and the front index does not satisfy the front face determination criterion. In the case (“NO” in step S24), the sum of the front index to be used is further calculated (step S26).

  Then, the front face determination unit 113 determines whether or not the total value of the front index satisfies the front face determination criterion (step S27), and when the front face determination criterion is satisfied (“YES” in step S27). If the total value of the front index does not satisfy the front face determination criterion (“NO” in step S27), it is determined that the face is not a front face (step S28). Also, the front face determination unit 113 determines that the face is not a front face even if there is no combination that satisfies the detection criterion in Step S27 ("NO") (Step S28).

  Finally, the face detection unit 110 determines whether or not to perform the front face detection process for the next face image (step S29). If the detection process is performed, the process returns to step S21, and the detection process is not performed. If this is the case, the process ends.

  Note that the determination reference value is arbitrarily set. As the determination reference value is higher, the face is not determined to be a front face unless the face is directed in a direction closer to the front. In an environment such as a factory where the programmable display 2 is used, the mouth and nose are often hidden by wearing a mask or a hat. In this case, it may be set so that the front ratio is not calculated for each combination of eyebrows and nose, eyebrows and mouth, contour and nose, and contour and mouth.

  Subsequently, a method of calculating the inclination performed by the inclination calculating unit 112 will be specifically described with reference to FIGS.

FIG. 11 shows a face directly in front, and in the following description, the direction along the straight line connecting the centers of both eyes is the horizontal direction, and the direction along the straight line connecting the centers of both eyes is the vertical direction. Here, the slope Sen is calculated for the combination of eyes and nose. First, let Le1 be a straight line extending in the vertical direction from the center of the right eye, and let Le2 be a straight line extending in the vertical direction from the center of the left eye. Similarly, let Ln be a straight line extending in the vertical direction from the center of the nose. Here, when the distance between the straight line Le1 and the straight line Ln is Den1, and the distance between the straight line Le2 and the straight line Ln is Den2, the slope Sen is
Sen = ((Den2-Den1) / (Den1 + Den2)) × 100
Is calculated. Since Den1 = Den2 when the face is in front, the slope Sen = 0 (%).

  FIG. 12A shows a face slightly facing right, and FIG. 12B shows a face slightly facing left. In FIGS. 12A and 12B, eyes, nose, eyebrows, and the like can be detected. Therefore, in the determination based on the above-described face component detection, the front face is determined. Here, straight lines Le1, Le2, and Ln and distances Den1 and Den2 are set as in the case of the face in front of FIG. When the face is facing right (FIG. 12 (a)), Den1 <Den2 is satisfied, so the slope Sen> 0 (%), and when the face is facing left (FIG. 12 (b)), Den1> Den2, so the slope is Sen <0 (%). The inclination Sen approaches 100 (%) as the face turns to the right, and the inclination Sen approaches -100 (%) as the face turns to the left. That is, the slope Sen indicates the deviation of the relative position between the eyes and the nose from the relative position between the eyes and the nose in the true front face.

  In addition to the eyes and nose, the inclination is also calculated for each combination of eyebrows and nose, eyebrows and mouth, eyes and mouth, nose and contour, eyebrows and contour, eyes and contour, and mouth and contour.

For example, in FIG. 11, the slope Sno in the combination of the nose and the contour is the horizontal distance between the central portion of the nose and the contour on the right side of the face, Dno1, and the horizontal distance between the central portion of the nose and the contour on the left side of the face. If the distance in the direction is Dno2, the slope Sno is
Sno = ((Dno1-Dno2) / (Dno1 + Dno2)) × 100
Is calculated. In FIG. 11, since Dno1 = Dno2, Fno = 0 (%). On the other hand, when the face is facing right, Dno1 <Dno2 and Sno> 0 (%), and when the face is facing left, Dno1> Dno2 and Sno <0 (%). Note that Sen approaches 100 (%) as the face turns to the right, and Sen approaches -100 (%) as the face turns to the left.

Similarly, in FIG. 11, the slope Seo in the combination of the eyes and the contour is represented by the horizontal distance between the center of the right eye and the contour of the right side of the face as Deo1, and the horizontal direction between the center of the left eye and the contour of the left side of the face If the distance is Deo2, the slope Seo is
Seo = ((Deo1-Deo2) / (Deo1 + Deo2)) × 100
Is calculated.

  Further, a method for calculating the inclination in the combination of other components will be described with reference to FIG. The face shown in FIG. 13 and the face shown in FIG. 11 are the same. In FIG. 13, straight lines Le1, Le2, and Ln are set as in FIG. Further, a straight line extending in the vertical direction from the inner end of the right eyebrow is set as Lb1, a straight line extending in the vertical direction from the inner end of the left eyebrow is set as Lb2, and a straight line extending in the vertical direction from the center of the mouth is set as Lm. In FIG. 13, the straight line Ln and the straight line Lm are the same straight line.

First, the slope Sbn in the combination of the eyebrows and the nose is given by assuming that the horizontal distance between the straight line Lb1 and the straight line Ln is Dbn1, and the horizontal distance between the straight line Lb2 and the straight line Ln is Dbn2.
Sbn = ((Dbn1−Dbn2) / (Dbn1 + Dbn2)) × 100
Is calculated.

The inclination Sbm in the combination of the eyebrows and the mouth is expressed as follows. When the horizontal distance between the straight line Lb1 and the straight line Lm is Dbm1, and the horizontal distance between the straight line Lb2 and the straight line Lm is Dbm2, the inclination Sbm is
Sbm = ((Dbm1−Dbm2) / (Dbm1 + Dbm2)) × 100
Is calculated. In FIG. 13, Dbn1 = Dbm1 and Dbn2 = Dbm2.

The slope Sem in the combination of the eyes and the mouth is expressed as follows. When the horizontal distance between the straight line Le1 and the straight line Lm is Dem1, and the horizontal distance between the straight line Le2 and the straight line Lm is Dem2, the slope Sem is
Sem = ((Dem1−Dem2) / (Dem1 + Dem2)) × 100
Is calculated.

The inclination Sbo in the combination of the eyebrow and the contour is the horizontal distance between the inner edge of the right eyebrow and the right contour Dbo1, and the horizontal distance between the inner edge of the left eyebrow and the left contour. Assuming Dbo2, the slope Sbo is
Sbo = ((Dbo1-Dbo2) / (Dbo1 + Dbo2)) × 100
Is calculated.

The slope Smo in the combination of the mouth and the contour is the slope when the horizontal distance between the mouth center and the right contour is Dmo1, and the horizontal distance between the mouth center and the left contour is Dmo2. Smo is
Smo = ((Dmo1-Dmo2) / (Dmo1 + Dmo2)) × 100
Is calculated.

  As described above, the programmable display 2 in the first embodiment and the automatic door 10 in the second embodiment both have the technical features of the face detection units 211 and 14 that detect the front face of a person. Has a remarkable effect. In the present embodiment, the configuration using the technique for detecting the face in front of a person for the programmable display and the automatic door has been described, but the present invention is not limited to this.

  For example, a technique for detecting the face in front of a person can be used for TV ON / OFF control, and when a person is not watching the screen for a certain period of time, the screen may be turned off so that only the voice can be heard. Also, by using technology for detecting the front face of a person in a vending machine, if the person is not in the vicinity of the vending machine, the illumination intensity is reduced and the person is looking at the product in the vending machine Only in some cases, lighting may be brightened or advertising signs may be issued. Similarly, technology that detects the face of a person's front face is used in the show window sensor so that only when a person is looking at a product in the show window, the light is brightened or a sign of advertising is issued. May be. In addition, by using a technology that detects the front face of a person in an ATM device of a financial institution, a screen is displayed only when a person is looking at the ATM display, and the ATM display is displayed only when the person passes in front of the ATM. If the screen is not viewed, the screen may not be displayed on the ATM display. In any of the above configurations, power consumption can be reduced.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The technology for detecting the front face of a person according to the present invention can be suitably applied to screen display devices such as a programmable display and a television, and automatic doors and vending machines.

It is a block diagram which shows the principal part structure of the control system which has a programmable display which concerns on this invention. (A), (b) is a front view of the said programmable display, (a) has shown the state in which a backlight is ON, (b) has shown the state in which a backlight is OFF. It is a flowchart of the screen display control function which concerns on this invention. It is a flowchart which concerns on the modification of the screen display control function which concerns on this invention. It is a block diagram which shows the principal part structure of the automatic door which concerns on this invention. It is a front view of the automatic door. (A), (b) is a front view of the said automatic door. It is a block diagram which shows the structure of the face detection part which detects a front face in the said control system and the said automatic door. It is a block diagram which shows the other structure of the face detection part which detects a front face in the said control system and the said automatic door. It is a flowchart of the determination of the front face by the positional relationship of the detection component which concerns on this invention. It is a figure which shows the face which faced the front. (A) is a figure which shows the face which faced right a little, (b) is a figure which shows the face which faced slightly left. It is a figure which shows the face which faced the front.

Explanation of symbols

2 Programmable display (screen display device)
211 face detection unit (face detection means)
212 Screen control unit (screen control means)
22 Display 25 Backlight 6 Camera 10 Automatic door 11 Door 13 Door engine control unit (door control means)
14 Face detection unit (face detection means)
16 Camera 100 Face detection unit (face detection means)
110 Face detection unit (face detection means)
111 Facial component detection unit (facial component detection means)
112 Inclination degree calculation part (Inclination degree calculating means)
113 Front degree determination unit (front determination means)

Claims (19)

A screen display device for displaying a screen on a display,
Face detection means for detecting the presence of a face in front of a person in a video of a camera that captures the front of the display;
A screen display device comprising: screen control means for displaying a screen saver screen on the display when the face detection means does not detect the presence of a face in front of a person for a predetermined time.   2. The screen display device according to claim 1, wherein the screen control means cancels the display of the screen saver screen when the face detection means detects the presence of a face in front of a person.   The screen control means detects the presence of a face in front of a person and determines that the distance between the face and the display is shorter than a predetermined distance, and cancels the display of the screen saver screen. The screen display device according to claim 1.   The screen control means detects the presence of a face in front of a person, and determines that the distance between the face and the display is shorter than a predetermined distance and the position of the face is the same for a predetermined time. The screen display device according to claim 1, wherein display of the screen saver screen is canceled. A screen display device that displays a screen on a display with a backlight,
Face detection means for detecting the presence of a face in front of a person in a video of a camera that captures the front of the display;
A screen display device comprising: screen control means for turning off the backlight when the face detection means does not detect the presence of a face in front of a person for a predetermined time.   6. The screen display device according to claim 5, wherein the screen control means turns on the backlight when the face detection means detects the presence of a face in front of a person.   The screen control means is characterized in that when the face detection means detects the presence of a face in front of a person and determines that the distance between the face and the display is shorter than a predetermined distance, the backlight is turned on. The screen display device according to claim 5.   The screen control means detects the presence of a face in front of a person, and determines that the distance between the face and the display is shorter than a predetermined distance and the position of the face is the same for a predetermined time. The screen display device according to claim 5, wherein the backlight is turned on.   The face detection means determines that the human face is a front face when a predetermined facial part is detected from the human face in the video of the camera among eyes, nose, mouth, eyebrows and ears. The screen display device according to claim 1, wherein: The face detection means detects face parts detection means for detecting two or more face parts among eyes, nose, mouth, eyebrows and contours from a human face of the camera image;
Among the detected face parts, in the combination of two face parts,
An inclination calculating means for calculating an inclination indicating a deviation of the relative positions of the facial parts of each combination from the relative positions of the facial parts in the true front face;
When the inclination of at least one of the selected combinations is within a predetermined range, and the front index preset for the combination is equal to or greater than a reference value, the human face is The screen display device according to claim 1, further comprising a front face determination unit that determines that the face is a front face.   The front face determination means sums the front indices of each selected combination when the front index of any combination of the selected combinations is less than the reference value, and the total value is equal to or greater than the reference value. The screen display device according to claim 10, wherein the human face is determined to be a front face at a certain time.   The screen display control program for functioning a computer as the said face detection means and the said screen control means of the screen display apparatus of any one of Claims 1-11.   A computer-readable recording medium on which the screen display control program according to claim 12 is recorded. In automatic doors that automatically open and close the door,
Face detection means for detecting the presence of a face in front of a person in the image of a camera that images the front of the automatic door;
An automatic door comprising: door control means for opening the door for a predetermined time when the face detecting means detects the presence of a face in front of a person.   The door control means opens the door for a predetermined time when the face detection means detects the presence of a face in front of a person and determines that the distance between the face and the door is shorter than a predetermined distance. And automatic door.   The door control means detects that the face detection means detects the presence of a face in front of a person, determines that the distance between the face and the door is shorter than a predetermined distance, and the position of the face is the same for a predetermined time. An automatic door characterized in that the door is opened for a predetermined time.   The face detection means determines that the human face is a front face when a predetermined facial part is detected from the human face in the video of the camera among eyes, nose, mouth, eyebrows and ears. The automatic door according to any one of claims 14 to 16. The face detection means detects face parts detection means for detecting two or more face parts among eyes, nose, mouth, eyebrows and contours from a human face of the camera image;
Among the detected face parts, in the combination of two face parts,
An inclination calculating means for calculating an inclination indicating a deviation of the relative positions of the facial parts of each combination from the relative positions of the facial parts in the true front face;
When the inclination of at least one of the selected combinations is within a predetermined range, and the front index preset for the combination is equal to or greater than a reference value, the human face is The automatic door according to any one of claims 14 to 16, further comprising a front face determination unit that determines that the face is a front face.   The front face determination means sums the front indices of each selected combination when the front index of any combination of the selected combinations is less than the reference value, and the total value is equal to or greater than the reference value. 19. The automatic door according to claim 18, wherein the human face is determined to be a front face at a certain time.

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