JP5388238B2 - Tactile display device, tactile display method, and program - Google Patents

Description

  The present invention relates to a tactile display device, a tactile display method, and a program for recognizing a display by using tactile characters.

  When presenting information to a visually impaired person, a display device (tactile display device) called a Braille display or a tactile display is often used.

  In such a tactile display device, if the device is not surrounded by a cover, the braille displayed on the display may be peeped by a third party.

  In order to prevent this, it is conceivable to newly install a dedicated device, but it takes man-hours and costs for the development and installation of the device.

  In addition, a technique for providing a sensor for detecting that the finger has approached or touched the display surface and controlling the protrusion of the tactile pin based on the detection result of the sensor has been considered (for example, patents). Reference 1).

JP 2006-084946 A

  However, the technique described in Patent Document 1 has a problem in that it is difficult to project the tactile pin at an accurate timing. For example, if the timing of projecting the tactile pin is too early, peeping cannot be completely prevented. On the other hand, if the timing of projecting the tactile pin is too late, it will project when the finger is already touching the tactile pin, so that it cannot be read with the same feeling as usual.

  In addition, there is a problem that the distance between the finger and the tactile display cannot be detected. Therefore, when the user only moves his / her finger to change the reading position, if the finger is detected by the sensor and the tactile pin protrudes, the displayed content There is a risk of peeping from.

  As described above, the above-described technique lacks the accuracy of detection, and cannot prevent the timing at which the finger actually passes over the tactile pin and the timing at which the tactile pin protrudes. In addition, there is a problem that an enormous number of sensors are required to detect fine movements of tactile reading by sensors.

  An object of the present invention is to provide a tactile display device, a tactile display method, and a program that solve the above-described problems.

The tactile display device of the present invention is
By projecting from one surface, a plurality of tactile pins constituting Braille,
Two cameras that respectively photograph the surfaces on which the tactile pins are arranged from different directions;
A distance measuring unit that measures a distance between an object photographed by the cameras and the surface based on images photographed by the two cameras;
A motion calculation unit that calculates the direction and speed of movement of the object captured by the two cameras based on images captured by the two cameras;
A control unit that controls protrusion of the tactile pin based on the distance measured by the distance measurement unit and the direction and speed of movement of the object calculated by the motion calculation unit;

Further, the tactile display method of the present invention includes:
A tactile display method for displaying information using a plurality of tactile pins constituting Braille by protruding from one surface,
A process of photographing each of the surfaces on which the tactile pins are arranged from different directions;
A process of measuring a distance between the photographed object and the surface based on the photographed image;
Processing for calculating the direction and speed of movement of the photographed object based on the photographed image;
Based on the measured distance and the calculated direction and speed of movement of the object, a process of controlling the protrusion of the tactile pin is performed.

The program of the present invention is
A program for causing a device provided with a plurality of tactile pins that form Braille by projecting from one surface and two cameras,
Using the two cameras, photographing each of the surfaces on which the tactile pins are arranged from different directions;
A procedure for measuring the distance between the photographed object and the surface based on the photographed image;
A procedure for calculating the direction and speed of movement of the photographed object based on the photographed image;
Based on the measured distance and the calculated direction and speed of the movement of the object, a procedure for controlling the protrusion of the tactile pin is executed.

  As described above, in the present invention, precise control of the tactile pin can be performed.

It is a figure which shows one Embodiment of the tactile display apparatus of this invention. It is a figure which shows an example of the external appearance of the tactile display apparatus shown in FIG. It is the figure which looked at the tactile pin shown in FIG. 1 from the upper direction of the tactile display device. It is a figure which shows an example of the method in which the tactile pin shown in FIG. 1 expresses Braille. It is a figure for demonstrating the protrusion / non-projection state of the tactile pin shown in FIG. It is a flowchart for demonstrating the tactile display method in the tactile display apparatus shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing an embodiment of a tactile display device of the present invention.

  As shown in FIG. 1, the tactile display device 100 according to the present embodiment includes a tactile display 110, a tactile pin 120, cameras 130-1 and 130-2, a distance measuring unit 140, a motion calculating unit 150, and a control. Part 160 is provided. FIG. 1 shows only the components related to the present invention among the components included in the tactile display device 100.

  The tactile display 110 is composed of one surface (for example, a flat surface), and displays information using Braille by the protrusion of the tactile pin 120.

  The tactile pin 120 is composed of a plurality of pins, and forms a braille by projecting from the tactile display 110. Therefore, the tactile pin 120 has a shape such as a length that can be recognized as Braille when protruding from the tactile display 110.

  The cameras 130-1 and 130-2 have a photographing function and photograph the entire surface (tactile display 110) on which the tactile pins 120 are arranged from different directions. The cameras 130-1 and 130-2 output the captured images to the distance measurement unit 140 and the motion calculation unit 150.

  Also, one camera (for example, camera 130-1; the same applies to the following description) is configured such that the height of the tactile display 110 or the height of the tactile pin 120 when the tactile pin 120 protrudes (the tactile pin). It is arranged so as to photograph the horizontal direction with respect to the surface (tactile display 110) at a height substantially equal to the height of the front end of 120).

  Further, the other camera (for example, the camera 130-2. The same applies to the following description) has a height different from the height of the arrangement position of the camera 130-1, and the tactile display 110 obliquely below the tactile display 110. And the horizontal position is arranged at a position different from the arrangement position of the camera 130-1. At this time, the finger of the user who performs tactile reading is disposed on the back side of the tactile display device 100 as viewed from the user so that the finger of the user is not hidden behind the other finger or wrist with respect to the camera 130-2.

  The distance measuring unit 140 is based on the images output from the cameras 130-1 and 130-2, and the distance between the object (finger) and the surface (tactile display 110) captured by the cameras 130-1 and 130-2 ( Measure height. Here, from the arrangement as described above, the distance measurement unit 140 measures the distance (height) based on the image output from the camera 130-1 suitable for measuring the height. . In addition, the distance measurement unit 140 outputs the measured distance to the control unit 160.

  The motion calculation unit 150 calculates the moving direction and speed of the object (finger) photographed by the cameras 130-1 and 130-2 based on the images output from the cameras 130-1 and 130-2.

  The motion calculation unit 150 calculates the position of the object (finger) when calculating the direction and speed of movement. In the calculation of this position, the camera 130-1 and 130-2 are used to three-dimensionally photograph the target finger and the tactile display 110 from different directions, and thus the finger position is specified from the photographing result. be able to. The motion calculation unit 150 stores position information indicating the calculated position in a memory (not shown) for each frame of the image. Note that the frame rate of the image is not specified. For example, it may be 30 fps (frame per second) or 60 fps.

  In addition, the motion calculation unit 150 calculates the direction and speed of the movement of the object based on the past motion of the object photographed by the cameras 130-1 and 130-2. Specifically, the motion calculation unit 150 calculates the finger movement direction and speed of the latest one frame based on the difference between the position information of the previous frame and the current finger position information. Also, the motion calculation unit 150 calculates the finger movement direction and speed between the past five frames based on the finger position information of the past five frames stored in the memory. Such an algorithm for calculating the direction and speed of movement based on the past location may be a commonly used algorithm. Further, the number of frames such as “one frame before” and “the past five frames” is not limited to this number.

  In addition, the motion calculation unit 150 outputs the calculated direction and speed of the finger movement of the latest one frame and the calculated direction and speed of the finger movement during the past five frames to the control unit 160.

  The control unit 160 controls the protrusion of the tactile pin 120 based on the distance output from the distance measurement unit 140 and the moving direction and speed of the object output from the motion calculation unit 150. At this time, based on the direction and speed of the finger movement of the last one frame and the direction and speed of the finger movement during the past five frames output from the motion calculation unit 150, the control unit 160 The position of the moving destination is determined, and the protrusion of the tactile pin 120 is controlled based on the determined position and the distance output from the distance measuring unit 140. More specifically, the control unit 160 controls the protrusion of the tactile pin when the distance output from the distance measurement unit 140 is equal to or less than a predetermined threshold. That is, when the distance output from the distance measuring unit 140 is equal to or less than the predetermined threshold, the control unit 160 causes the tactile pin 120 disposed at a position corresponding to the determined position to protrude.

  FIG. 2 is a diagram showing an example of the appearance of the tactile display device 100 shown in FIG.

  The tactile display device 100 shown in FIG. 1 is provided with a tactile display 110 having tactile pins 120 of 720 × 480, as shown in FIG. It is also possible to do. In addition, two cameras 130-1 and 130-2 are provided for determining whether or not the user is willing to read and tracking the reading locus.

  FIG. 3 is a view of the tactile pin 120 shown in FIG. 1 as viewed from above the tactile display device 100.

  As shown in FIG. 3, a plurality of tactile pins 120 constitute a tactile pin group 121 (a set of tactile pins 120 surrounded by a thick line frame shown in the figure). Represents the points of Braille components. A plurality of tactile pins 120 constituting the tactile pin group 121 are given a subtle difference in height to express a curved surface in a pseudo manner so that a tactile sensation when a user performs tactile reading is genuine. It is close to.

  FIG. 4 is a diagram illustrating an example of a method in which the tactile pin 120 illustrated in FIG. 1 expresses Braille.

  Japanese braille expresses one character with six irregularities. Therefore, as shown in FIG. 4, one character is represented by one set of irregularities of the six tactile pin groups 121. In addition, one tactile pin group 121 includes a plurality of tactile pins 120, and each tactile pin 120 can have an arbitrary height.

  FIG. 5 is a diagram for explaining a protruding / non-projecting state of the tactile pin 120 illustrated in FIG. 1.

  Of the tactile pins 120 shown in FIG. 5, the left tactile pin 120 is in a state of protruding from the surface of the tactile display 110 (protruding state). 5 is a state when the right tactile pin 120 is retracted from the surface of the tactile display 110 (non-projecting state). Control of the projecting / non-projecting state of the tactile pin 120 is performed by the control unit 160 as described above. The mechanism for performing this control may be, for example, one using a magnet, another mechanical one, and is not particularly defined.

  Hereinafter, a tactile display method in the tactile display device 100 shown in FIG. 1 will be described.

  FIG. 6 is a flowchart for explaining a tactile display method in tactile display device 100 shown in FIG.

  First, the position of the finger is specified by the motion calculation unit 150 based on the images photographed by the cameras 130-1 and 130-2, and the finger height (finger finger) is identified based on the image photographed by the camera 130-1. Distance from the tactile display 110) is measured by the distance measuring unit 140 (step S1). The method for specifying the finger position by the motion calculation unit 150 is as described above. Further, height information indicating the measured height is output from the distance measurement unit 140 to the control unit 160.

  Thereafter, the motion calculation unit 150 reads the position information of the previous frame stored in the memory, and based on the difference between the position indicated by the position information and the current finger position, The direction and speed of movement are calculated (step S2).

  Further, the motion calculation unit 150 reads the finger position information of the past five frames stored in the memory, and based on the position indicated by the position information, the direction and speed of the finger movement between the past five frames is determined. Calculated (step S3).

  The results calculated in steps S2 and S3 are output from the motion calculation unit 150 to the control unit 160.

  Then, the control unit 160 outputs “the direction and speed of finger movement of the latest one frame” (hereinafter, information A) output from the motion calculation unit 150, and “the direction of finger movement for the past five frames and Based on the “speed” (hereinafter referred to as information B), the position to which the object moves is determined as the predicted position (step S4).

  At this time, the control unit 160 may determine the predicted position by taking an average value of the information A and the information B, or based on information A and B multiplied by a predetermined weight, respectively. It is also possible to determine the expected position. For example, an operation in which the weighting of the information A and the information B is changed depending on whether the user is a tactile reader or a beginner can be considered. It is known that the proficiency and the beginner have different trajectory traits. The track of the proficiency is almost a straight line from left to right. On the other hand, the trajectory of a beginner sways finely in the vertical direction (y direction), tends to return from the right to the left (x direction), and frequently changes in direction to 180 degrees. Therefore, in order to prevent losing sight of the tracking target, the weight of the information A may be increased for beginners.

  Subsequently, the control unit 160 determines whether or not the height (distance) indicating the height information output from the distance measuring unit 140 is equal to or less than a preset threshold value (step S5). For example, when the threshold is “3 mm”, the control unit 160 determines whether the height indicating the height information output from the distance measuring unit 140 is 3 mm or less.

  When the height indicating the height information output from the distance measuring unit 140 is equal to or less than the threshold value, it is determined that the user is going to perform palpation and is arranged at the expected position determined in step S4. The control unit 160 projects the tactile pin 120 that is being held (step S6).

  On the other hand, when the height indicating the height information output from the distance measuring unit 140 is not less than the threshold value, it is determined that the user is changing the tactile reading position, and the tactile pin 120 is not projected. .

  Thereafter, it is determined by the control unit 160 whether or not a preset time has elapsed (step S7).

  When the predetermined time has elapsed, the tactile pin 120 projected in step S6 is retracted (non-projected) by the control unit 160 (step S8).

  Although this predetermined time is not particularly defined, it is necessary to withdraw quickly to prevent peeping from a third party. Therefore, if the position of the protruding tactile pin 120 is not the expected movement position of the finger. The time that can be withdrawn in the shortest time. In addition, this time depends on the performance of the mechanism that causes the tactile pin 120 of the control unit 160 to project / not project.

  The above operation is repeated for each frame in the tactile display device 100.

  Here, the proximity sensor described in the background can determine only two states of “approaching” or “not approaching”. However, in photographing with a camera like the present invention, the proximity distance is determined. Specifically, it can be determined numerically.

  There are several types of proximity sensors. Typical examples include high-frequency oscillation types that use electromagnetic induction, magnetic types that use magnets, and capacitance types that use changes in capacitance. . For example, in a high-frequency oscillation type proximity sensor, the detection accuracy changes depending on whether the object is made of metal or nonmetal, and is also affected by the surrounding environment. In addition, the sensors affect each other. In either type, the object is to detect whether the object has approached using analog hardware technology, and it is theoretically difficult to distinguish a difference of several millimeters.

  The present invention described above has the following effects.

  The first effect is that it is possible to protect the privacy of a visually impaired person who is difficult to grasp the surrounding situation. The tactile pin 120 protruding timing is accurate, and it is determined whether the user is trying to perform palpation or just moving his / her finger to change the palpation position. The knowledge pin 120 is protruded. For this reason, even if a malicious third party takes a video, the personal information is not known.

  The second effect is that unlike a conventional product, it is not necessary to provide a dedicated device or a huge number of sensors, and therefore, it can be realized at a low cost.

  The third effect is that tactile reading can be performed with the same feeling as usual because the timing of protruding the tactile pin 120 is accurate.

  In addition to the above-described embodiment, there is also a method that changes the number of frames in the past that is used as the determination material for determining the predicted movement position in accordance with the magnitude of blurring of the user's palpation trajectory. Conceivable.

  The processing performed by each component provided in the tactile display device 100 described above may be performed by a logic circuit that is produced according to the purpose. In addition, a computer program (hereinafter referred to as a program) in which processing contents are described as a procedure is recorded on a recording medium readable by the tactile display device 100, and the program recorded on the recording medium is read by the tactile display device 100. , May be executed. The recording medium readable by the tactile display device 100 includes a transferable recording medium such as a floppy (registered trademark) disk, a magneto-optical disk, a DVD, and a CD, as well as a ROM, a RAM, and the like built in the tactile display device 100. Memory, HDD, etc. The program recorded on the recording medium is read by the control unit 160 provided in the tactile display device 100, and the same processing as described above is performed under the control of the control unit 160. Here, the control unit 160 operates as a computer that executes a program read from a recording medium on which the program is recorded.

DESCRIPTION OF SYMBOLS 100 Tactile display apparatus 110 Tactile display 120 Tactile pin 121 Tactile pin group 130-1, 130-2 Camera 140 Distance measurement part 150 Motion calculation part 160 Control part

Claims (7)

By projecting from one surface, a plurality of tactile pins constituting Braille,
Two cameras that respectively photograph the surfaces on which the tactile pins are arranged from different directions;
A distance measuring unit that measures a distance between an object photographed by the cameras and the surface based on images photographed by the two cameras;
A motion calculation unit that calculates the direction and speed of movement of the object captured by the two cameras based on images captured by the two cameras;
A tactile display device comprising: a control unit that controls protrusion of the tactile pin based on the distance measured by the distance measurement unit and the direction and speed of movement of the object calculated by the motion calculation unit. The tactile display device according to claim 1,
The tactile display device according to claim 1, wherein one of the two cameras is disposed so as to capture a horizontal direction with respect to the surface at substantially the same height as the surface. The tactile display device according to claim 1 or 2,
The tactile display device, wherein the motion calculation unit calculates the direction and speed of movement of the object based on the past movement of the object taken by the camera. The tactile display device according to any one of claims 1 to 3,
The said control part controls protrusion of the said tactile pin, when the distance which the said distance measurement part measured is below a predetermined threshold value, The tactile display apparatus characterized by the above-mentioned. The tactile display device according to any one of claims 1 to 4,
The control unit determines a position to which the object moves based on the moving direction and speed of the object calculated by the motion calculating unit, and the determined position and the distance measured by the distance measuring unit. The tactile display device controls the protrusion of the tactile pin based on the above. A tactile display method for displaying information using a plurality of tactile pins constituting Braille by protruding from one surface,
A process of photographing each of the surfaces on which the tactile pins are arranged from different directions;
A process of measuring a distance between the photographed object and the surface based on the photographed image;
Processing for calculating the direction and speed of movement of the photographed object based on the photographed image;
A tactile display method that performs a process of controlling protrusion of the tactile pin based on the measured distance and the calculated direction and speed of movement of the object. In a device provided with a plurality of tactile pins that form Braille by projecting from one surface and two cameras,
Using the two cameras, photographing each of the surfaces on which the tactile pins are arranged from different directions;
A procedure for measuring the distance between the photographed object and the surface based on the photographed image;
A procedure for calculating the direction and speed of movement of the photographed object based on the photographed image;
A program for executing a procedure for controlling protrusion of the tactile pin based on the measured distance and the calculated direction and speed of movement of the object.

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