Warm and cold sense presentation device, two-point discrimination threshold measurement method, inter-presentation part distance calculation method and program

Abstract

To quickly present an integral warm and cold sense.SOLUTION: A warm and cold sense presentation device comprises: an air generation unit which generates air being cold air or hot air; and a plurality of presentation units which discharges the air generated by the air generation unit. An inter-presentation unit distance being a distance between the adjacent presentation units is equal to or less than a minimum distance necessary for discriminating a cold sense or a warm sense at two points on the skin.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hot / cold sensation providing device, a two-point discrimination threshold measuring method, a presentation unit distance calculating method, and a program. [Background technology]

[0002] Conventionally, techniques have been proposed for presenting a sense of warmth and cold to the skin of a subject. A device that applies a temperature stimulus by contacting the skin of a subject is known (for example, Patent Document 1). In addition, techniques for presenting a sense of warmth and cold without contact are known (for example, Non-Patent Document 1 and Non-Patent Document 2). The technique described in Non-Patent Document 1 presents a sense of warmth and cold without contact using mist or hot air. The technique described in Non-Patent Document 2 presents a sense of warmth and cold without contact using a cold air current. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-022617 A [Non-patent literature]

[0004] [Non-Patent Document 1] P. Han, C. Hsieh, Y. Chen, J. Hsiao, K. Lee, S. Ko, K.Chen, C. Chou, Y. Hung, AoEs: Enhancing Teleportation Experience in Immersive Environment with Mid-Air Haptics, "SIGGRAPH '17: ACM SIGGRAPH 2017 Emerging Technologies July 2017 Article No.: 3”, July 30, 2017, p.1-2 [Non-Patent Document 2] J. Xu, S. Yoshimoto, N. Ienaga, Y. Kuroda, Intensity-Adjustable Non-contact Cold Sensation Presentation Based on the Vortex Effect, "IEEE Transactions on Haptics", July 1, 2022, p.1-11 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the technology described in Patent Document 1, since thermal stimuli are applied by contacting the subject's skin, it may not be possible to provide a natural sensation. According to the technology described in Non-Patent Document 1, the air around the subject is replaced. According to the technology described in Non-Patent Document 1, the presented thermal sensation is highly dependent on the temperature and size of the room, and the time required for presentation increases and the power consumption increases. According to the technology described in Non-Patent Document 2, it is not possible to present a thermal sensation with a sense of unity. As described above, the conventional techniques have been unable to quickly present a consistent sense of temperature and cold.

[0006] The present invention has been made in consideration of the above points, and provides a thermal sensation presentation device, a two-point discrimination threshold measurement method, a presentation unit distance calculation method, and a program that can quickly present a thermal sensation with a sense of unity. [Means for solving the problem]

[0007] The present invention has been made to solve the above-mentioned problems, and one aspect of the present invention is a warm / cold sensation presentation device comprising an air generating unit that generates air, which is either cold air or hot air, and a plurality of presentation units that eject the air generated by the air generating unit, wherein the inter-presentation unit distance, which is the distance between adjacent presentation units, is equal to or less than the minimum distance required to distinguish between the cold sensation or the warm sensation at two points on the skin.

[0008] In one aspect of the present invention, the cold sensation presentation device further includes a mounting unit to which the plurality of presentation units are fixed and which is mounted on a user's body.

[0009] In one aspect of the present invention, in the above-mentioned cold sensation presentation device, the mounting unit further includes an adjustable unit that changes the positions at which the multiple presentation units are fixed on the mounting unit.

[0010] In addition, one aspect of the present invention is a cold sensation presentation device further comprising a control unit that controls the flow rate of the cold air generated by the air generating unit, and the control unit controls the flow rate of the cold air in conjunction with an image displayed in a virtual reality space by a display device.

[0011] Moreover, one aspect of the present invention is a method for measuring a two-point discrimination threshold, which is the minimum distance required to discriminate between cold and warm sensations at two points on the skin, comprising: a first presentation unit, which is a presentation unit that discharges air generated by an air generating unit that generates cold air or hot air, and a second presentation unit, which is also a presentation unit, disposed directly above a surface of a body of a subject; changing a position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit increases, while acquiring ascending series answer information indicating an answer as to whether or not the subject felt cold or warm at two points for each distance; changing a position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit decreases, while acquiring descending series answer information indicating an answer as to whether or not the subject felt cold or warm at two points for each distance; and calculating a two-point discrimination threshold based on the ascending series answer information and the descending series answer information.

[0012] Another aspect of the present invention is a method for calculating a distance between multiple presentation units in a warm / cold sensation presentation device including an air generating unit that generates air, which is cold air or hot air, and multiple presentation units that discharge the air generated by the air generating unit, the method including calculating a distance between the presentation units, the distance being a distance between the presentation units and a skin surface to which the air is discharged from the presentation units, a diameter value of the presentation units, a Nusselt number at a stagnation point of a single jet, and a Nusselt number at a collision point where jets discharged from adjacent presentation units collide with each other relative to the Nusselt number at the stagnation point. a ratio of the stagnation point and the diameter of the presenting portion to the stagnation point; calculating a Nusselt number at the collision point based on the acquired Nusselt number at the stagnation point and the acquired ratio; and calculating a distance from the stagnation point to the collision point as a maximum value of the distance between the presenting portions, based on a linear relationship between the Nusselt number and the distance from the stagnation point, when a value obtained by non-dimensionalizing the distance from the stagnation point by the diameter of the presenting portion is greater than a predetermined value, from the acquired distance value, the acquired diameter value, and the calculated Nusselt number at the collision point.

[0013] Moreover, one aspect of the present invention is a program for measuring a two-point discrimination threshold, which is the minimum distance required to discriminate between cold and warm sensations at two points on the skin, comprising: a first presentation unit that is a presentation unit that ejects air generated by an air generating unit that generates cold air or hot air, and a second presentation unit that is also a presentation unit, disposed directly above a surface of a body of a subject; and a program for causing a computer to execute the following steps: acquiring ascending series answer information indicating an answer as to whether or not the subject felt cold or warm at two points, for each distance, while changing the position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit increases; acquiring descending series answer information indicating an answer as to whether or not the subject felt cold or warm at two points, for each distance, while changing the position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit decreases; and calculating a two-point discrimination threshold based on the ascending series answer information and the descending series answer information.

[0014] Another aspect of the present invention is a program for calculating an inter-presentation-unit distance, which is a distance between a plurality of presentation units in a warm / cold sensation presentation device including an air generating unit that generates air, which is cold air or hot air, and a plurality of presentation units that discharge the air generated by the air generating unit, the program including a computer that acquires a value of a diameter of the presentation unit, a Nusselt number at a stagnation point of a single jet, and a ratio of the Nusselt number at the stagnation point to the Nusselt number at a collision point where jets discharged from adjacent presentation units collide with each other; The program executes the steps of: calculating the Nusselt number at the collision point based on the value of the distance between a surface and the presentation portion, the acquired Nusselt number at the stagnation point, and the acquired ratio; and calculating the distance from the stagnation point to the collision point as the maximum value of the distance between the presentation portions, based on the acquired value of the distance, the acquired value of the diameter, and the calculated Nusselt number at the collision point, based on a linear relationship between the Nusselt number and the distance from the stagnation point when the value obtained by non-dimensionalizing the distance from the stagnation point by the diameter of the presentation portion is greater than a predetermined value. Effect of the Invention

[0015] According to the present invention, a sense of temperature and cold can be quickly presented with a sense of unity. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing an example of the configuration of a cold sensation presentation device according to a first embodiment of the present invention. [Diagram 2] FIG. 11 is a perspective view showing an example of the configuration of a two-point discrimination threshold measurement system according to a second embodiment of the present invention. [Diagram 3] FIG. 11 is a top view showing an example of the configuration of a two-point discrimination threshold measurement system according to a second embodiment of the present invention. [Figure 4] FIG. 11 is a diagram showing an example of a method for measuring a two-point discrimination threshold by a two-point discrimination threshold measurement system according to a second embodiment of the present invention. [Diagram 5]FIG. 11 is a diagram showing an example of a procedure for measuring a two-point discrimination threshold by a two-point discrimination threshold measurement system according to a second embodiment of the present invention. [Figure 6] FIG. 11 is a diagram showing an example of the results of measuring the cold sensation two-point discrimination threshold of a cold air flow based on the method of limits according to the second embodiment of the present invention. [Figure 7] FIG. 11 is a diagram showing an example of a functional configuration of a two-point discrimination threshold measurement device according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a diagram showing an example of a two-point discrimination threshold calculation process according to the second embodiment of the present invention. [Figure 9] FIG. 11 is a diagram showing conditions for providing a sense of unity with respect to a first modified example of the second embodiment of the present invention. [Figure 10] FIG. 13 is a diagram showing the relationship between the behavior of a jet depending on the magnitude of a flow rate and the Nusselt number according to the first modified example of the second embodiment of the present invention. [Figure 11] FIG. 13 is a graph showing a quantitative Nusselt number for each flow rate, which is derived from a theoretical formula according to a first modified example of the second embodiment of the present invention. [Figure 12] FIG. 13 is a diagram showing the relationship between the Nusselt number of a single jet and the distance from a stagnation point SP1 according to a first modified example of the second embodiment of the present invention. [Figure 13] FIG. 13 is a diagram showing an example of an arrangement of presentation units in which the distance between presentation units satisfies the condition for presenting a sense of unity in coolness in the first modified example of the second embodiment of the present invention. [Figure 14] FIG. 13 is a diagram illustrating an example of a functional configuration of a presentation unit distance calculation device according to a first modified example of the second embodiment of the present invention. [Figure 15] FIG. 13 is a diagram illustrating an example of a display unit distance calculation process according to a first modified example of the second embodiment of the present invention. [Figure 16] FIG. 13 is a diagram showing a ratio of Nusselt numbers of cold two-point discrimination thresholds at each flow rate according to the first modified example of the second embodiment of the present invention. [Figure 17] FIG. 13 is a diagram showing an example of a third method for determining the inter-presenting unit distance according to the second modified example of the second embodiment of the present invention. [Figure 18]FIG. 13 is a diagram showing an example of a third method for determining the inter-presenting unit distance according to the second modified example of the second embodiment of the present invention. [Figure 19] FIG. 13 is a diagram showing an example of a third method for determining the inter-presenting unit distance according to the second modified example of the second embodiment of the present invention. [Figure 20] FIG. 11 is a diagram showing an example of a one-dimensional arrangement of a presentation unit according to a second embodiment of the present invention. [Figure 21] FIG. 11 is a diagram showing a two-dimensional arrangement of a presentation unit according to a comparative example of the second embodiment of the present invention. [Figure 22] FIG. 11 is a diagram showing an example of a two-dimensional arrangement of a presentation unit according to a second embodiment of the present invention. [Diagram 23] FIG. 11 is a perspective view showing an example of the appearance of a wearing device according to a third embodiment of the present invention. [Figure 24] FIG. 11 is a top view showing an example of the appearance of a wearing device according to a third embodiment of the present invention. [Diagram 25] FIG. 13 is a perspective view showing an example of the appearance of a wearing device according to a first modified example of the third embodiment of the present invention. [Figure 26] FIG. 13 is a perspective view showing an example of the appearance of a wearing device according to a second modified example of the third embodiment of the present invention. [Figure 27] FIG. 13 is a rear view showing an example of the appearance of a wearing device according to a second modified example of the third embodiment of the present invention. [Figure 28] FIG. 13 is a perspective view showing an example of the appearance of a wearing device according to a third modified example of the third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] (First embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a diagram showing an example of the configuration of a cold sensation display device 1 according to this embodiment. In the following, a three-dimensional orthogonal coordinate system of X-axis, Y-axis, and Z-axis will be used for explanation when necessary. In the explanation of each embodiment, "display" and "presentation" are synonymous.

[0018] The cold sensation presentation device 1 includes a cold air generating unit 2, a tube 3, a plurality of presentation units 4, and a control unit 5. In the example shown in Fig. 1, the number of the plurality of presentation units 4 is two.

[0019] The cold air generating unit 2 generates a predetermined flow rate of cold air 6. The cold air generating unit 2 uses a vortex tube as a cold air source. The vortex tube separates compressed air supplied from an air compressor (not shown) into warm air and cold air by creating a vortex flow. The cold air generating unit 2 outputs the cold air from the warm air and cold air separated in the vortex tube to tube 3.

[0020] The tube 3 is connected to the cold air generating unit 2. The tube 3 branches into multiple parts, each of which has a nozzle at its tip. In the example shown in Fig. 1, the tube 3 branches into two. The tube 3 guides the cold air 6 generated by the cold air generating unit 2 to each of the multiple presentation units 4.

[0021] The multiple presentation units 4 discharge the cold air 6 generated by the cold air generation unit 2. Each of the multiple presentation units 4 has an outlet at the tip where the tube 3 branches. The outlet is a nozzle. The presentation unit 4 discharges the cold air 6 onto the user's skin surface. Here, the presentation units 4 are oriented so that the cold air 6 is discharged from a direction approximately perpendicular to the skin surface. The outlet of the presentation unit 4 is not in contact with the skin surface, and the multiple presentation units 4 present the sensation of cold without contact. The maximum flow rate of each nozzle is 25 L / min.

[0022] Here, the inter-presentation unit distance D1 is the distance between adjacent presentation units 4. The minimum distance required to discriminate between cold and warm sensations at two points on the skin is called the two-point discrimination threshold. In the cold sensation presentation device 1, the inter-presentation unit distance D1 is equal to or smaller than the two-point discrimination threshold.

[0023] The control unit 5 includes, for example, a computer that operates according to a predetermined program, and controls each part of the cold sensation presentation device 1. For example, the control unit 5 controls the flow rate of cold air generated by the cold air generation unit 2. The control unit 5 controls the flow rate of cold air by controlling a solenoid valve provided in the cold air generation unit 2. In controlling the solenoid valve, the control unit 5 changes the opening degree of the solenoid valve to an opening degree corresponding to a PWM (pulse width modulation) current. Note that the control of the flow rate includes starting and stopping the discharge of cold air.

[0024] In the cold sensation providing device 1, the distance D1 between the providing units is equal to or smaller than the two-point discrimination threshold, so that when cold air is discharged onto two points on the skin by the two providing units 4, the user cannot discriminate between the cold sensations at the two points. Therefore, the user is provided with a sense of unity in the cold sensation.

[0025] A unified cold sensation is a sensation that is unified to the extent that the cold sensations at two points on the skin are indistinguishable. For example, when a person puts their hand into a cold object such as ice or water, the part of the body that is in contact with the object feels as if it is wrapped in something cold, and when they are in the Antarctic or on a snowy mountain, they feel as if the exposed skin is surrounded by cold air. In this way, when a person experiences cold or chilly weather, the area of ​​the skin that is in contact with the object or air feels a single unified coldness, not a separate one.

[0026] In recent years, interest in Virtual Reality (VR) has increased, and in addition to visual and tactile presentation, research into temperature sensation presentation has been actively conducted. Temperature sensation can express the characteristics of an object when touching it from an environment such as cold or hot. Therefore, it is expected that presenting the user with temperature sensation in addition to visual presentation will improve the sense of realism and enable greater immersion in the VR space.

[0027] In order to improve the sense of realism through temperature sensation in a VR experience, it is necessary to present a cold space with a sense of unity on the skin surface in conjunction with the VR experience. The cold sensation presentation device 1 can present a sense of unity to the user, so it is suitable for use in a VR experience. In FIG. 1, as an example, a cold sensation felt around the arm when putting one's hand under a waterfall is presented to a user wearing a head-mounted display.

[0028] The timing at which cold air 6 is presented by the cold sensation presentation device 1 and the synchronization with the image displayed in the VR space are controlled by the control unit 5. In other words, the control unit 5 controls the flow rate of the cold air 6 in conjunction with the image displayed in the VR space by the display device. With this configuration, the cold sensation presentation device 1 can improve the sense of realism through temperature sensation in the VR experience.

[0029] A specific example in which the cold sense exhibiting device 1 is worn on the user's body will be described later in a third embodiment.

[0030] In the present embodiment, an example in which the number of the multiple presentation units 4 is two has been described, but the present invention is not limited to this. The number of the multiple presentation units 4 may be three or more. As described above, the inter-presentation-unit distance D1 is equal to or less than the two-point discrimination threshold. As long as the inter-presentation-unit distance D1 satisfies the condition of being equal to or less than the two-point discrimination threshold, it may be determined according to the number of the multiple presentation units 4 or the size of the cold sensation presentation device 1.

[0031] The distance between the skin surface onto which the cool air 6 is discharged and the presentation unit 4 (referred to as the presentation distance) is determined so as to satisfy, for example, the condition H / d0≦4, which will be described later. Here, H is the presentation distance, and d0 is the nozzle diameter of the presentation unit 4.

[0032] In the present embodiment, an example in which the air discharged by the multiple presentation units 4 is cool air has been described, but the present invention is not limited to this. Hot air may be discharged by the multiple presentation units 4.

[0033] As described above, the hot / cold sensation presentation device according to this embodiment (the cold sensation presentation device 1 in this embodiment) includes an air generating unit (the cold air generating unit 2 in this embodiment) and a plurality of presentation units 4. The air generating section (in this embodiment, the cold air generating section 2) generates air that is cold air or hot air (in this embodiment, the cold air 6). The multiple presentation units 4 discharge air (cold air 6 in this embodiment) generated by an air generation unit (cold air generation unit 2 in this embodiment). The inter-presentation-unit distance D1, which is the distance between adjacent presentation units 4, is equal to or smaller than the minimum distance required to discriminate between cold sensation and warm sensation at two points on the skin (that is, the two-point discrimination threshold).

[0034] With this configuration, the cold sensation presentation device 1 according to this embodiment can discharge air with the distance between adjacent presentation units 4 set to be equal to or less than the two-point discrimination threshold, so that a unified warm / cold sensation can be presented quickly. Here, quickly presenting a warm / cold sensation means presenting the warm / cold sensation almost at the same time as air is discharged from the presentation unit 4. In conventional technology (see, for example, Non-Patent Document 1), coldness is reproduced by changing the air environment around the person's body itself by blowing hot or cold air from a fan onto the entire body from one direction, so it takes time to reproduce the environment. The cold sensation presentation device 1 according to this embodiment can present a warm / cold sensation in a shorter time than conventional technology that reproduces the environment by changing the air environment around the body itself.

[0035] Second embodiment In this embodiment, a method for determining the inter-presentation unit distance D1 in the cold sensation presentation device 1 will be described. In this embodiment, a two-point discrimination threshold is measured, and the inter-presentation unit distance D1 is determined to be a distance equal to or less than the measured two-point discrimination threshold. FIG. 2 is a perspective view showing an example of the configuration of a two-point discrimination threshold measurement system 10 according to this embodiment. FIG. 3 is a top view showing an example of the configuration of a two-point discrimination threshold measurement system 10 according to this embodiment. The two-point discrimination threshold measurement system 10 is a system for measuring a two-point discrimination threshold.

[0036] The two-point discrimination threshold measurement system 10 includes a vortex tube 11, an electromagnetic valve 12, a branching section 13, a tube 14, a presentation section 15, and an actuator 16. In the two-point discrimination threshold measurement system 10, the presentation section 15 is connected to the vortex tube 11 that generates a cold air flow via the tube 14. The cold air flow output from the vortex tube 11 is branched into two at the branching section 13 and guided to the two presentation sections 15 via the two tubes 14, respectively. The actuator 16 changes the inter-presentation unit distance D2. The inter-presentation unit distance D2 is the distance between the two presentation units 15.

[0037] FIG. 4 is a diagram showing an example of a method for measuring the two-point discrimination threshold by the two-point discrimination threshold measurement system 10 according to the present embodiment. In the measurement of the two-point discrimination threshold by the two-point discrimination threshold measurement system 10, the cold two-point discrimination threshold was measured by the method of limits when a cold air flow was presented to the outside of the upper arm of the subject under the condition that the distance D2 between the presentation units was changed in 10 stages. The distance D2 between the presentation units was changed in 10 stages of 50, 70, 90, 110, 130, 150, 170, 190, 210, and 230 mm by the actuator 16. The measurement was performed in two cases: when a visual image corresponding to the cold sensation presentation was displayed on the display 19, and when a visual image was not displayed.

[0038] As shown in Fig. 4(C), the subject's upper arm was fixed at a position distance H1 from the discharge port of the presentation unit 15. Distance H1 was 30 mm. In order to fix the subject's upper arm at a position distance H1 from the discharge port, a fixing unit 111 and a cushion 112 shown in Fig. 4(B) were installed. The subject placed his / her middle finger in the fixing unit 111 to fix the position of the arm. This made the distance between the discharge port and the upper arm constant.

[0039] During the measurement, a partition 110 was placed between the subject and the two-point discrimination threshold measurement system 10. Furthermore, the subject was made to wear noise-canceling headphones 18 and white noise was played to suppress the influence of visual and auditory sensations. Hot plate 17 keeps the skin temperature of the subject's upper arm constant at the start of measurement. Emergency stop button 113 is a button for stopping measurement.

[0040] FIG. 5 is a diagram showing an example of a procedure for measuring the two-point discrimination threshold by the two-point discrimination threshold measurement system 10 according to the present embodiment. The inner side of the forearm is placed on the hot plate 17 set at 33° C. for 30 seconds to keep the skin temperature constant (step S1). Next, the arm is placed on the two-point discrimination threshold measurement system 10 (step S2). As a task for the subject, two cold stimuli are presented from each of the presentation units 15 (step S3). While gradually widening the presentation unit distance D2, the subject answers by "yes" or "no" using the keyboard as to whether or not the cold stimuli from each of the two presentation units 15 are felt at two points (step S4). The cold sensation presentation time is three seconds. The series in which the presentation unit distance D2 is gradually widened is called an ascending series.

[0041] After the ascending series is completed, place the inside of the forearm on the hot plate 17 again for 30 seconds to keep the skin temperature constant. Finally, place the arm on the two-point discrimination threshold measurement system 10, and while gradually narrowing the inter-presentation distance D2, answer "yes" or "no" using the keyboard as to whether or not the cold stimuli from each of the two presentation units 15 are felt at two points. The series in which the inter-presentation distance D2 is gradually narrowed is called the descending series. The flow from step S1 to step S4 is counted as one set, and measurements are performed in three sets while changing the flow rate of cold air. Furthermore, the above measurements are performed for a total of 15 trials.

[0042] The method of limits, a type of psychophysical measurement, is known as a method for measuring the two-point cold discrimination threshold. In the method of limits, presentation begins from a state in which the two cold sensations are not felt separately, and the distance D2 between the presentation parts is gradually increased until the cold sensations are felt separately (ascending series). On the other hand, from a state in which the cold sensations are felt separately, the distance D2 between the presentation parts is gradually decreased until the cold sensations are no longer felt separately (descending series). Measurements are performed by repeating the ascending and descending series, and the two-point cold discrimination threshold is derived from equation (1).

[0043]

number

[0044] The results of measuring the two-point discrimination threshold for cold airflow based on the method of limits using the two-point discrimination threshold measuring system 10 are shown in Fig. 6. Fig. 6 shows the measurement results both when a visual image is not displayed and when a visual image is displayed.

[0045] When no visual image was displayed, the cold two-point discrimination threshold was maximum at 132.5 mm when the flow rate was 15 L / min, and minimum at 124.4 mm when the flow rate was 25 L / min. The average cold two-point discrimination threshold at each flow rate was 129.1 ± 2.943 mm.

[0046] In the measurement results when a visual image was displayed, the cold two-point discrimination threshold reached its maximum value of 142.2 mm when the flow rate was 5 L / min, and reached its minimum value of 133.3 mm when the flow rate was 25 L / min. The average cold two-point discrimination threshold at each flow rate was 138.0 ± 2.730 mm. Finally, a two-way analysis of variance showed that there were no statistically significant differences in the cold two-point discrimination threshold for any of the factors: flow rate (p=0.11), image (p=0.61), or interaction (p=0.84).

[0047] According to the measurement results using the two-point discrimination threshold measurement system 10, the two-point discrimination threshold of cold sensation of the cold air flow felt by the subject hardly changed when the flow rate was changed. In addition, according to the measurement results using the two-point discrimination threshold measurement system 10, no effect was observed on the two-point discrimination threshold of cold sensation by the presence or absence of a visual image being displayed.

[0048] Now, with reference to FIG. 7, a two-point discrimination threshold measurement device 20, which is a computer used in the two-point discrimination threshold measurement system 10, will be described. 7 is a diagram showing an example of a functional configuration of the two-point discrimination threshold measurement device 20 according to this embodiment. The two-point discrimination threshold measurement device 20 includes a presentation unit position change unit 21, a response information acquisition unit 22, a calculation unit 23, and an output unit 24.

[0049] The presentation unit position change unit 21 changes the inter-presentation unit distance D2. The presentation unit position change unit 21 changes the position of at least one of the first presentation unit (one of the presentation units 15) and the second presentation unit (the other of the presentation units 15) so that the inter-presentation unit distance D2 increases. That is, the presentation unit position change unit 21 changes the inter-presentation unit distance D2 based on the ascending sequence. Also, the presentation unit position change unit 21 changes the position of at least one of the first presentation unit and the second presentation unit so that the inter-presentation unit distance D2 decreases. That is, the presentation unit position change unit 21 changes the inter-presentation unit distance D2 based on the descending sequence. The presentation unit position change unit 21 changes the inter-presentation unit distance D2 by controlling the actuator 16 (see FIG. 2).

[0050] The answer information acquiring unit 22 acquires ascending series answer information and descending series answer information. The ascending series answer information indicates an answer as to whether or not the subject felt a cold sensation at 2 points for each inter-presentation unit distance D2 included in the ascending series when the inter-presentation unit distance D2 is changed to increase based on the ascending series. The descending series answer information indicates an answer as to whether or not the subject felt a cold sensation at 2 points for each inter-presentation unit distance D2 included in the descending series when the inter-presentation unit distance D2 is changed to decrease based on the descending series. The answer information acquiring unit 22 acquires answers by the subject from a keyboard.

[0051] The calculation unit 23 calculates a two-point discrimination threshold based on the ascending series answer information and the descending series answer information. The calculation unit 23 calculates the two-point discrimination threshold based on the above-mentioned formula (1). The output unit 24 outputs the two-point discrimination threshold calculated by the calculation unit 23. The output unit 24 outputs the two-point discrimination threshold as a measurement result to, for example, a computer used by the measurer, the display 19, or the like.

[0052] The two-point discrimination threshold measurement device 20 is a computer equipped with a CPU (Central Processing Unit), a main storage device, an auxiliary storage device, and an interface. The operations of the presentation unit position change unit 21, the answer information acquisition unit 22, the calculation unit 23, and the output unit 24 are stored in the auxiliary storage device in the form of a program. The CPU reads out the program from the auxiliary storage device, expands it in the main storage device, and executes the operation of each unit according to the program.

[0053] The visual image displayed on the display 19 may be output to the display 19 by the two-point discrimination threshold measurement device 20, or may be output by a computer separate from the two-point discrimination threshold measurement device 20.

[0054] Next, a two-point discrimination threshold calculation process in which the two-point discrimination threshold measurement device 20 calculates a two-point discrimination threshold will be described with reference to Fig. 8. The two-point discrimination threshold calculation process corresponds to the process of the computer (i.e., the two-point discrimination threshold measurement device 20) in the measurement by the above-mentioned two-point discrimination threshold measurement system 10. Fig. 8 is a diagram showing an example of the two-point discrimination threshold calculation process according to this embodiment.

[0055] Step S10: The answer information acquiring unit 22 acquires ascending series answer information when the distance between the first presentation unit and the second presentation unit is changed so as to increase.

[0056] Step S20: The answer information acquiring unit 22 acquires descending series answer information when the distance between the first presentation unit and the second presentation unit is changed so as to decrease.

[0057] Step S30: The calculation unit 23 calculates a two-point discrimination threshold based on the ascending sequence answer information and the descending sequence answer information. With the above, the two-point discrimination threshold measurement device 20 ends the two-point discrimination threshold calculation process.

[0058] According to the two-point discrimination threshold measurement system 10 of this embodiment, the two-point discrimination threshold can be calculated based on the ascending series answer information and the descending series answer information, so that the two-point discrimination threshold can be calculated with higher accuracy than when the calculation is performed based on only one of the ascending series answer information and the descending series answer information.

[0059] The two-point discrimination threshold measuring system 10 according to this embodiment may be used to test for peripheral nerve disorders such as diabetes.

[0060] (First modified example of the second embodiment) In this embodiment, a sense of cold is presented with a sense of unity based on the Nusselt number. The Nusselt number is a dimensionless number that represents the ratio of heat transfer and heat conduction in a convecting fluid, and can be used as an index of the ability of a gas to take heat away from a target object. In this embodiment, the cold air 6 discharged from the presentation unit 4 is sometimes called a single jet. Figure 9 shows the conditions for presenting a sense of cold with a sense of unity. As shown in Figure 9, the maximum Nusselt number Nu at the stagnation point SP1 of the single jet is max A sense of unity in cold sensation is presented by overlapping the jet groups at a distance where the ratio of the Nusselt number Nu at any point in the presentation range to the distance between the Nusselt number and the presentation range is greater than or equal to a specified value (X percent).

[0061] In order to provide a uniform cold sensation, the maximum Nusselt number Nu max The reason why the ratio of the Nusselt number Nu at any point in the presentation range to the actual value must be greater than or equal to a certain value is that humans have a perceptual characteristic that makes them sensitive to relative changes. Such perceptual characteristics are known as Weber's law.

[0062] FIG. 10 shows the relationship between the behavior of the jet depending on the flow rate and the Nusselt number. Physically, as shown in FIG. 10(A), when the flow rate of the jet is high, the jet 61 discharged from the presentation unit 4 tends to move straight in the direction of discharge. As a result, as can be seen from the graph G1 showing the values ​​of the Nusselt number, a very large amount of heat is lost at the stagnation point, and the amount of heat lost is relatively small at positions away from the stagnation point. On the other hand, as shown in FIG. 10(B), when the flow rate is low, the jet 62 discharged from the presentation unit 4 tends to diffuse. As a result, as can be seen from the graph G2 showing the values ​​of the Nusselt number, the amount of heat lost is relatively large at positions away from the stagnation point.

[0063] The quantitative Nusselt number derived from the theoretical formula is shown for each flow rate in Figure 11. The qualitative relationship between the flow rate and the Nusselt number shown in Figure 10 can also be confirmed from the quantitative relationship based on the theoretical formula shown in Figure 11.

[0064] In order to present a sense of coolness with a sense of unity by the group of jets, it is necessary to appropriately set the distance between the presentation units. There are two possible methods for determining the distance between the presentation units: a first method and a second method. The first method is a method for deriving the degree of heat taken away from each part of the target object by the jets based on the Nusselt number. The second method is a method for determining the distance between the presentation units based on the distance perceived as a sense of coolness with a sense of unity by a measurement of a human being, as described in the first embodiment. According to the measurement results by the two-point discrimination threshold measurement system 10 described in the first embodiment, the distance between the presentation units obtained by the first method and the distance between the presentation units obtained by the second method are not inconsistent.

[0065] The graph of the Nusselt number for each flow rate shown in Fig. 11 can be obtained by expanding the domain of the theoretical formula in jet engineering. In this embodiment, the expansion of the theoretical formula will be described. The distance from the stagnation point of a single jet is r [mm], and the inner diameter of the nozzle is d0 [mm]. The dimensionless number obtained by non-dimensionalizing r by d0 is shown in equation (2).

[0066]

Number

[0067] Here, let the Nusselt number at the stagnation point be Nu0, the Nusselt number be Nu, the Prandtl number be Pr, the Reynolds number be Re, the presenting distance be H, the nozzle diameter be d0, and the distance from the stagnation point be r. In jet engineering, when H / d0 ≤ 4, the theoretical formula for the Nusselt number at the stagnation point of a circular impinging jet is expressed as in Equation (3).

[0068]

Number

[0069] On the other hand, when 2.5 ≤ r / d0 ≤ 7.5, 2×10³ ≤ Re ≤ 4×10⁵, and 2 < H / d0 < 12, it is expressed as in Equation (4).

[0070]

Number

[0071] In Equation (4), G is expressed as in Equation (5), and F is expressed as in Equation (6).

[0072]

Number

[0073]

Number

[0074] Also, when 0 ≤ r / d0 ≤ 2.5, the Nusselt number Nux at position x is expressed as a fourth-order equation of x as in Equation (7).

[0075]

Number

[0076] In equation (7), a, b, and c are each constant.

[0077] c can be found from the condition that the Nusselt number shown by formula (7) and the Nusselt number shown by formula (2) have the same value at x=0. In addition, from the condition that the Nusselt number shown by formula (4) and the Nusselt number shown by formula (7) have the same value at x=2.5, and the condition of smoothness of the Nusselt number that the value obtained by differentiating the Nusselt number shown by formula (4) with respect to x at x=2.5 and the value obtained by differentiating the Nusselt number shown by formula (7) with respect to x have the same value, the simultaneous equations shown in formula (8) are established.

[0078]

number

[0079] The coefficients a, b, and c of equation (7) can be found by solving equation (8) under the condition x = 2.5.

[0080] From the measurement results obtained by the two-point discrimination threshold measurement system 10 in the first embodiment, it is considered that the distance from the stagnation point to the collision point falls within the range indicated by r / d0≧7.5. When r / d0≧7.5, it is assumed that there is linearity between the Nusselt number and the distance, and the Nusselt number Nux at the position x is expressed as shown in equation (9).

[0081]

number

[0082] In formula (9), d and e are constants. d and e can be found by solving the simultaneous equations obtained from the condition that the Nusselt number shown by formula (4) and the Nusselt number shown by formula (9) have the same value at x=7.5, and the value obtained by differentiating the Nusselt number shown by formula (4) with respect to x at x=7.5 and the value obtained by differentiating the Nusselt number shown by formula (9) with respect to x have the same value. In other words, d and e can be found by solving the simultaneous equations obtained from the condition that the Nusselt number is continuous and smooth at x=7.5.

[0083] FIG. 12 is a diagram showing the relationship between the Nusselt number of a single jet and the distance from the stagnation point SP1 according to this modified example. Here, the position where adjacent jets collide with each other is called the collision point. In graph G3 shown in FIG. 12, distance DX1 corresponds to the distance from the stagnation point SP1 to the collision point. Assuming that the Nusselt number at the collision point is X [%] of the maximum Nusselt number of each jet, the Nusselt number at the collision point Nu M is expressed as in equation (10).

[0084]

number

[0085] The Nusselt number Nu given by equation (9) x The Nusselt number at the collision point, Nu, given by equation (10) M Substituting and solving for x gives us equation (11).

[0086]

number

[0087] Since x is the value of the nozzle inner diameter made dimensionless by d0 as shown in equation (2), when it is converted back to r, which has the dimension of distance, equation (12) is obtained.

[0088]

number

[0089] The r shown in equation (12) is nothing but the distance from the stagnation point of a single jet to the impingement point. Therefore, when the Nusselt number is used, the distance between the presentation units is determined based on the condition shown in equation (13).

[0090]

number

[0091] In formula (13), L is the distance D2 between the presentation parts, and L1 is twice the distance from the stagnation point to the collision point. In other words, the condition for presenting a unified cold sensation is that the distance between the presentation parts when using the Nusselt number is less than twice the distance from the stagnation point to the collision point.

[0092] Fig. 13 shows an example of the arrangement of the display units 4 where the distance between the display units 4 satisfies the condition for presenting a unified sense of coolness as expressed by formula (13). However, it is assumed that the jets of air discharged from each display unit 4 are air currents with similar heat transfer conditions.

[0093] Now, with reference to FIG. 14, a presentation unit distance calculation device 30, which is a computer that calculates the presentation unit distance when the Nusselt number is used, will be described. 14 is a diagram showing an example of a functional configuration of the inter-presenter distance calculation device 30 according to this modified example. The inter-presenter distance calculation device 30 includes an acquisition unit 31, a collision point Nusselt number calculation unit 32, an inter-presenter distance calculation unit 33, an output unit 34, and a storage unit 35.

[0094] The acquisition unit 31 acquires input parameters for calculating the distance between the presentation units. The input parameters are the presentation distance H, the diameter value d0 of the presentation unit 4, and the maximum Nusselt number Nu at the stagnation point SP1 of the single jet. max And, Nu M / Nu max It consists of. M / Nu maxis the maximum Nusselt number Nu at the stagnation point SP1 max The Nusselt number Nu at the collision point CP1, which is the position where the jets discharged from the adjacent presentation units 4 collide with each other, is M is the ratio of.

[0095] The collision point Nusselt number calculation unit 32 calculates the Nusselt number at the stagnation point SP1 acquired by the acquisition unit 31 and the ratio Nu M / Nu max Based on this, the Nusselt number Nu at the collision point CP1 is M Here, the collision point Nusselt number calculation unit 32 calculates the Nusselt number NuM based on the formula (10).

[0096] The presentation unit distance calculation unit 33 calculates the distance from the stagnation point SP1 to the collision point CP1 as the maximum value of the presentation unit distance D1 based on the relational equation information A1 from the presentation distance H acquired by the acquisition unit 31, the diameter value d0 acquired by the acquisition unit 31, and the Nusselt number NuM at the collision point CP1 calculated by the collision point Nusselt number calculation unit 32. The relational equation information A1 is information indicating the above-mentioned equations (2) to (12).

[0097] Here, formula (12) is a formula derived based on the predetermined linear relationship shown by formula (9). The predetermined linear relationship is a linear relationship between the Nusselt number and the distance from the stagnation point SP1 when the value x obtained by non-dimensionalizing the distance from the stagnation point SP1 using the diameter of the presentation unit 4 is greater than a predetermined value (i.e., x=7.5). Therefore, the presentation unit distance calculation unit 33 calculates the Nusselt number Nu at the collision point CP1 calculated by the collision point Nusselt number calculation unit 32 based on the presentation distance H acquired by the acquisition unit 31, the diameter value d0 acquired by the acquisition unit 31, and the Nusselt number Nu at the collision point CP1 calculated by the collision point Nusselt number calculation unit 32. M Based on a predetermined linear relationship, the distance from the stagnation point SP1 to the collision point CP1 is calculated as the maximum value of the inter-presentation-unit distance D1.

[0098] The output unit 34 outputs the maximum inter-presentation unit distance calculated by the inter-presentation unit distance calculation unit 33. The output unit 34 outputs the maximum inter-presentation unit distance to a computer or the like used by the manufacturer of the cold sensation presentation device 1.

[0099] The storage unit 35 stores various information. The information stored in the storage unit 35 includes relational expression information A1, maximum Nusselt number Nu max , ratio Nu M / Nu max Includes:

[0100] The inter-presentation unit distance calculation device 30 is a computer including a CPU (Central Processing Unit), a main storage device, an auxiliary storage device, and an interface. The operations of the acquisition unit 31, the collision point Nusselt number calculation unit 32, the inter-presentation unit distance calculation unit 33, and the output unit 34 are stored in the auxiliary storage device in the form of a program. The CPU reads out the program from the auxiliary storage device, expands it in the main storage device, and executes the operation of each unit according to the program.

[0101] Next, a process of calculating the distance between the presenting units, which is a process of calculating the maximum value of the inter-presenting unit distance by the inter-presenting unit distance calculation device 30, will be described with reference to Fig. 15. Fig. 15 is a diagram showing an example of the inter-presenting unit distance calculation process according to this modified example.

[0102] Step S110: The acquisition unit 31 acquires input parameters. As described above, the input parameters are the diameter value d0 of the presentation unit 4 and the maximum Nusselt number Nu at the stagnation point SP1 of the single jet. max And, Nu M / Nu max It consists of:

[0103] The acquisition unit 31 acquires a value input from a keyboard or the like as the presentation distance H. The acquisition unit 31 acquires a value input from a keyboard or the like as the diameter value d0 of the presentation unit 4. Note that, although the condition H / d0≦4 is assumed in the process of deriving the above-mentioned formula (3), the input presentation distance H and diameter value d0 do not have to be values ​​that satisfy the condition H / d0≦4. The acquisition unit 31 acquires the maximum Nusselt number Nu max is obtained from the storage unit 35. maxThe value obtained from the above-mentioned formula (2) and the literature value is stored in advance in the storage unit 35.

[0104] The acquisition unit 31 is a ratio Nu M / Nu max is obtained from the storage unit 35. M / Nu max is stored in advance in the storage unit 35. Here, the ratio Nu M / Nu max is obtained, for example, based on the measurement results of the two-point discrimination threshold. From the measurement results of the two-point discrimination threshold and equation (12), the Nusselt number Nu at the collision point CP1 is M is obtained.

[0105] For example, the above-mentioned two-point discrimination threshold measurement system 10 is used to measure the two-point discrimination threshold. From the measurement results by the two-point discrimination threshold measurement system 10, the distance from the stagnation point SP1 to the collision point CP1 is expressed by the ratio Nu M / Nu max Approximately 21 percent is the value of 20.95 ± 1.851 percent, more precisely.

[0106] The ratio of the Nusselt numbers of the cold two-point discrimination threshold at each flow rate is shown in Fig. 16. The ratio of the Nusselt numbers shown in Fig. 16 is a value obtained based on the measurement result by the two-point discrimination threshold measurement system 10 in the first embodiment and the theoretical formula explained in this embodiment.

[0107] In addition, the two-point discrimination threshold may be measured using a measurement method other than the two-point discrimination threshold measurement system 10. M / Nu max may be determined based on the Nusselt number measured for a single jet.

[0108] Step S120: The collision point Nusselt number calculation unit 32 calculates the Nusselt number Nu at the collision point CP1 based on the Nusselt number at the stagnation point SP1 acquired by the acquisition unit 31 and the ratio X acquired by the acquisition unit 31. M Calculate.

[0109] Step S130: The presentation-unit distance calculation unit 33 calculates the presentation distance H acquired by the acquisition unit 31, the diameter value d0 acquired by the acquisition unit 31, and the Nusselt number Nu at the collision point CP1 calculated by the collision-point Nusselt number calculation unit 32. M From this, the distance from the stagnation point SP1 to the collision point CP1 is calculated as the maximum value of the inter-presentation-unit distance D1 based on a predetermined linear relationship (i.e., equation (12)). Here, the inter-presentation-unit distance calculation unit 33 calculates the values ​​of the constants d and e included in equation (12) based on the relational equation information A1 by solving the simultaneous equations obtained from the condition that the Nusselt number is continuous and smooth at x=7.5 as described above.

[0110] Step S140: The output unit 34 outputs the maximum inter-presentation unit distance calculated by the inter-presentation unit distance calculation unit 33. With the above, the inter-presentation unit distance calculation device 30 ends the inter-presentation unit distance calculation process.

[0111] According to the inter-presentation-unit distance calculation device 30 of this modified example, the inter-presentation-unit distance can be calculated based on the Nusselt number, so that the inter-presentation-unit distance can be calculated as a value whose objectivity based on jet engineering is guaranteed.

[0112] (Second Modification of the Second Embodiment) The method of determining the presentation unit interval based on the Nusselt number described in the first modified example of the second embodiment above is called the first method. The method of determining the presentation unit interval using the two-point discrimination threshold measurement system 10 described in the second embodiment above is called the second method. In the second modified example of the second embodiment, a third method is described that determines the optimal inter-presentation unit distance taking into account physical and psychological aspects based on the results obtained from the first and second methods.

[0113] The third method is one of the following three methods. In method 3-1, the shorter of the inter-presenting unit distances obtained from the first and second methods is set as the maximum inter-presenting unit distance, as shown in Fig. 17. In method 3-1, the inter-presenting unit distance is selected from the distances equal to or less than the maximum value.

[0114] In method 3-2, as shown in FIG. 18, the arithmetic mean of the inter-presentation unit distances obtained from the first and second methods is determined as the optimal inter-presentation unit distance.

[0115] In method 3-3, as shown in Fig. 19, first, the difference between the inter-presenting unit distances obtained from the first method and the second method is calculated. Next, in method 3-3, the difference is subtracted from the shorter of the inter-presenting unit distances obtained from the first method and the second method, and the obtained distance value is determined as the optimal inter-presenting unit distance.

[0116] In the above, in this embodiment, a method for determining the inter-presentation unit distance has been described. In the following, a specific arrangement of the presentation units 4 will be described.

[0117] 20 is a diagram showing an example of a one-dimensional arrangement of the presentation units 4 according to this embodiment. When the presentation units 4 are arranged one-dimensionally, the Nusselt number Nu at the collision point CP1 of the adjacent jets is M Therefore, as shown in Fig. 20, the Nusselt number at the collision point CP1 is the maximum Nusselt number Nu max The value of X[%] is the ratio Nu M / Nu max It is.

[0118] Next, a case where the presentation unit 4 is arranged two-dimensionally will be described with reference to FIGS. First, as a comparative example, a two-dimensional arrangement of the presentation units 4 shown in Fig. 21 will be described. In the two-dimensional arrangement shown in Fig. 21, three presentation units 4 are arranged on the vertices of an equilateral triangle. The collision point CP1 of the adjacent jets is located at the maximum Nusselt number Nu max If the center of the equilateral triangle GP1 (center of the inscribed circle) is X [%] of the Nusselt number Nu M In order to feel a sense of unity, the Nusselt number in the presented range must be less than the maximum Nusselt number Nu max It must be X[%] of the total.

[0119] As shown in Fig. 22, the maximum Nusselt number Nu is calculated at the center GP2 of the equilateral triangle. max The nozzle is arranged so that the impingement occurs at X [%] of the stagnation point SP1. Then, the Nusselt number at any point in the entire presentation range is the maximum Nusselt number Nu max 22, the two-dimensional arrangement of the presentation units 4 shown in FIG. 22 allows for a uniform cold sensation presentation. Therefore, when the presentation units 4 are arranged in two dimensions, under the assumption that the inter-part distances D1 are all equal, the Nusselt number at any point within the presentation range is equal to the maximum Nusselt number Nu max Just arrange it so that the value is equal to or greater than X[%].

[0120] In addition, when hot air is discharged by multiple presentation units 4, it is preferable that the constants in equations (3), (4), and (5) described in the second modified example be changed to values ​​corresponding to the hot air.

[0121] (Third embodiment) In this embodiment, an application example of the cold sense exhibiting device 1 according to the above-described first embodiment as a device will be described. Fig. 23 is a perspective view showing an example of the appearance of the wearing device 100 according to this embodiment. Fig. 24 is a top view showing an example of the appearance of the wearing device 100 according to this embodiment. The wearing device 100 includes a mounting unit 101, a plurality of (for example, three) tubes 102, and a controller 104.

[0122] The mounting unit 101 is mounted on the arm of a user. A plurality of presentation units 103, which are the respective distal ends of a plurality of tubes 102, are fixed to the mounting unit 101. The controller 104 is a controller for operating a head mounted display (HMD).

[0123] Here, the distance between the presentation units differs for each user. As a first modification, a wearable device 100a in which the positions at which the plurality of presentation units are fixed are changeable will be described. 25 is a perspective view showing an example of the appearance of a wearing device 100a according to a first modified example of this embodiment. The wearing device 100a is different from the wearing device 100 in that the wearing part 101a has a plurality of lock holes 105a, a lane 106a, and a stopper 107a. The lock holes 105a are provided on both the upper and lower surfaces of the wearing part 101a. The lock holes 105a are arranged at equal intervals, for example.

[0124] The lock holes 105a and the lanes 106a constitute the variable section. The variable section changes the positions at which the multiple presentation units 103a are fixed in the mounting section 101a. The multiple presentation units 103a are installed on the lanes 106a. When a lock key (not shown) is not inserted in the lane 106a, the positions of the multiple presentation units 103a can be changed by sliding them on the lane 106a. Once the distance between the presentation units is determined, the positions of the presentation units 103a are fixed by inserting lock keys into the lock holes 105a from both the top and bottom sides of the mounting section 101a.

[0125] Moreover, if the number of the multiple presentation units 103a is insufficient, a new presentation unit can be added onto the lane 106a by removing the stopper 107a provided at the tip of the mounting unit 101a.

[0126] 25, an example in which the lock holes 105a are arranged at equal intervals and their positions on the mounting part 101a are fixed is described, but the present invention is not limited to this. A mechanism for moving the lock holes 105a on the mounting part 101a may be provided so that the positions of the lock holes 105a can be changed. Furthermore, the mounting part may be provided with a mechanism capable of moving and fixing the presentation part other than the lock hole. The mechanism may utilize, for example, a motor or a power such as an electromagnetic force.

[0127] The mounting unit 101a includes a variable section, which allows the positions at which the multiple presentation units 103a are fixed to be changed, so that the distance between the presentation units can be changed depending on the user who is wearing the mounting unit 101a.

[0128] FIG. 26 is a perspective view showing an example of the appearance of the wearing device 100b according to the second modified example of this embodiment. FIG. 27 is a rear view showing an example of the appearance of the wearing device 100b according to the second modified example of this embodiment. The wearing device 100b includes a wearing unit 101b, a plurality of tubes 102b, and an attachment unit 108b. As an example, the wearing device 100b is attached to a head mounted display 200 and worn around the neck of a user. The attachment unit 108b attaches the wearing unit 101b to the head mounted display 200.

[0129] In the wearable device 100b, similarly to the first modified example of this embodiment, the positions at which the multiple presentation units are fixed can be changed.

[0130] 28 is a perspective view showing an example of the appearance of a wearing device 100c according to a third modified example of this embodiment. The wearing device 100c includes a wearing section 101c and a plurality of tubes 102c. The wearing section 101c includes a plurality of lock holes 105c, a lane 106c, and a stopper 107c. The lock holes 105c and the lane 106c configure a variable section. The lock holes 105c are provided on the upper and lower surfaces of the wearing section 101c. The lock holes 105c are arranged at equal intervals, for example. In the mounting unit 101c, the method of changing the positions at which the multiple presentation units 103c are fixed is similar to that of the mounting unit 101a shown in FIG. 25, and therefore the description thereof will be omitted.

[0131] In the present embodiment and each modified example, an example in which the wearable device is worn on the user's arm or neck has been described, but the present invention is not limited to this. The wearable device may be worn on a body part other than the user's arm or neck (for example, the leg or back). The wearable device may also be worn on multiple parts of the user's body.

[0132] Wearable devices 100, 100a, 100b, and 100c according to this embodiment and its respective modified examples include wearing units 101, 101a, 101b, and 101c to which a plurality of presentation units are fixed and which are worn on the body of a user. With this configuration, in the wearable devices 100, 100a, 100b, and 100c of this embodiment and its respective modified examples, the cold sensation presentation device 1 in which the distance between the presentation parts is equal to or less than the two-point discrimination threshold can be used as a wearable device, so that a cold space with a sense of unity can be presented to the part of the body to which the wearable device is attached.

[0133] In addition, a part of the two-point discrimination threshold measurement device 20 or the inter-presentation distance calculation device 30 in the above-mentioned embodiment, for example, the presentation unit position change unit 21, the answer information acquisition unit 22, the calculation unit 23, the output unit 24, the acquisition unit 31, the collision point Nusselt number calculation unit 32, the inter-presentation distance calculation unit 33, and the output unit 34 may be realized by a computer. In this case, a program for realizing this control function may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed. In addition, the "computer system" referred to here is a computer system built into the two-point discrimination threshold measurement device 20 or the inter-presentation distance calculation device 30, and includes hardware such as an operating system (OS) and peripheral devices. In addition, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM (Read Only Memory), a CD-ROM (Compact Disc-Read Only Memory), and a storage device such as a hard disk built into a computer system. Furthermore, the term "computer-readable recording medium" may include a medium that dynamically stores a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, and a medium that stores a program for a certain period of time, such as a volatile memory inside a computer system that serves as a server or client in such a case. The above program may be one that realizes part of the above-mentioned functions, or may be one that can realize the above-mentioned functions in combination with a program already recorded in the computer system. In addition, a part or the whole of the two-point discrimination threshold measurement device 20 or the inter-presentation distance calculation device 30 in the above-mentioned embodiment may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each functional block of the two-point discrimination threshold measurement device 20 or the inter-presentation distance calculation device 30 may be individually processed, or a part or the whole may be integrated and processed. The integrated circuit method is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to the progress of semiconductor technology, an integrated circuit based on that technology may be used.

[0134] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes, etc. are possible within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0135] 1: cold sensation presentation device, 2: cold air generation unit, 4: presentation unit, 6: cold air, D1: distance between presentation units

Claims

1. An air generating unit that generates air, which is cold air or hot air; a plurality of presentation units that eject the air generated by the air generation unit; a control device that controls an amount of the air generated by the air generating unit to be discharged from the presenting unit; Equipped with The control device controls the amount of air discharged from the presentation unit, and the distance between the presentation units, which is the distance between the adjacent presentation units, is set to be equal to or less than the minimum distance required to distinguish between cold sensation and warm sensation at two points on the skin. A device that displays warm and cold sensations.

2. The display device further includes a mounting unit to which the plurality of display units are fixed and which is mounted on the user's body. The warm / cold sensation presenting device according to claim 1 .

3. The mounting unit further includes a variable unit that changes the positions at which the plurality of presentation units are fixed on the mounting unit. The warm / cold sensation presenting device according to claim 2 .

4. A control unit for controlling a flow rate of the cold air generated by the air generating unit is further provided. The control unit controls the flow rate of the cool air in conjunction with an image displayed in a virtual reality space by a display device. The warm / cold sensation presenting device according to claim 1 .

5. 1. A method for measuring a two-point discrimination threshold, which is the minimum distance required to discriminate between cold and warm sensations at two points on the skin, comprising: a first presentation unit that is a presentation unit that discharges air generated by an air generating unit that generates air, which is cold air or hot air, and a second presentation unit that is the presentation unit are disposed directly above a surface of the body of the subject; adjusting the amount of cold air or hot air discharged from the first presentation unit and the second presentation unit to a predetermined flow rate; acquiring ascending series answer information indicating an answer as to whether the subject felt a cold sensation or a warm sensation at two points for each distance while changing a position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit increases; acquiring descending series answer information indicating an answer as to whether or not the subject felt a cold sensation or a warm sensation at two points for each distance while changing a position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit decreases; Calculating a two-point discrimination threshold based on the ascending sequence response information and the descending sequence response information; A method for measuring a two-point discrimination threshold comprising the steps of:

6. A method for calculating a distance between multiple presentation units in a warm / cold sensation presentation device including an air generation unit that generates air, which is cold air or hot air, and multiple presentation units that discharge the air generated by the air generation unit, comprising: acquiring a value of a distance between the skin surface to which the air is discharged from the presentation unit and the presentation unit, a value of a diameter of the presentation unit, a Nusselt number at a stagnation point of a single jet, and a ratio of the Nusselt number at a collision point, which is a position where the jets discharged from adjacent presentation units collide with each other, to the Nusselt number at the stagnation point; Calculating a Nusselt number at the collision point based on the obtained Nusselt number at the stagnation point and the obtained ratio; calculating a distance from the stagnation point to the collision point as a maximum value of the distance between the presentation parts, based on a linear relationship between the Nusselt number and the distance from the stagnation point when a value obtained by making the distance from the stagnation point dimensionless by the diameter of the presentation part is greater than a predetermined value, from the acquired value of the distance, the acquired value of the diameter, and the calculated Nusselt number at the collision point; A method for calculating a distance between presentation units.

7. A program for measuring a two-point discrimination threshold, which is the minimum distance required to discriminate between cold and warm sensations at two points on the skin, comprising: a first presentation unit that is a presentation unit that discharges air generated by an air generating unit that generates air, which is cold air or hot air, and a second presentation unit that is the presentation unit are disposed directly above a surface of the body of the subject; On the computer, adjusting the amount of cold air or hot air discharged from the first presentation unit and the second presentation unit to a predetermined flow rate; a step of acquiring ascending series answer information indicating an answer as to whether the subject felt a cold sensation or a warm sensation at two points for each distance while changing a position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit increases; a step of acquiring descending series answer information indicating an answer as to whether or not the subject felt a cold sensation or a warm sensation at two points for each distance while changing a position of at least one of the first presentation unit and the second presentation unit so that the distance between the first presentation unit and the second presentation unit decreases; calculating a two-point discrimination threshold based on the ascending sequence response information and the descending sequence response information; A program for executing the above.

8. A program for calculating a distance between multiple presentation units in a warm / cold sensation presentation device including an air generation unit that generates air that is cold air or hot air, and multiple presentation units that discharge the air generated by the air generation unit, On the computer, obtaining a value of the diameter of the presentation portion, a Nusselt number at a stagnation point of a single jet, and a ratio of the Nusselt number at a collision point, which is a position where jets discharged from adjacent presentation portions collide with each other, to the Nusselt number at the stagnation point; calculating a Nusselt number at the collision point based on a value of a distance between the skin surface to which the air is discharged from the presentation unit and the presentation unit, the acquired Nusselt number at the stagnation point, and the acquired ratio; calculating a distance from the stagnation point to the collision point as a maximum value of the distance between the presentation parts, based on a linear relationship between the Nusselt number and the distance from the stagnation point when a value obtained by non-dimensionalizing the distance from the stagnation point using the diameter of the presentation part is greater than a predetermined value, from the acquired value of the distance, the acquired value of the diameter, and the calculated Nusselt number at the collision point; A program for executing the above.

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