Functional chairs and functional floor chairs

Abstract

To provide a functional chair in which a looking-down posture is corrected in the use of desktop or hand held computer equipment or in reading on the basis of human engineering, and fatigue of the whole hand and arm having computer equipment and a book is reduced, and thereby onset of straight neck is prevented, particularly, in the use such as a smartphone or in the reading without the use of a desk, effectiveness is exhibited.SOLUTION: A functional chair of the present invention is the chair used when desktop or hand-held computer equipment is used and including at least a seat surface, a backrest and an arm rest. In the arm rest, when the computer equipment gripped with both hands is approximately looked in the face in a seating state where a user brings back from buttocks into contact with the backrest and brings an elbow into abutment with the arm rest, an angle formed by normal passing an upper arm and an acromion point is formed forward in a shape becoming more than 0 degrees and 90 degrees or less in a body side view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a chair that prevents straight neck and maintains a healthy neck posture (hereinafter referred to as healthy neck posture) based on ergonomics when using a desktop or portable computer device or reading. [Background technology]

[0002] In today's digital society, opportunities to obtain information using desktop or portable computer devices have become increasingly common. Here, desktop or portable computer devices refer to personal computers, display-based game consoles, and portable game consoles, as well as smartphones and tablet PCs (hereinafter, "smartphones or tablets" are specifically referred to as "smartphones, etc."). Furthermore, by downloading game apps (a general term for application software classified as games) developed for mobile devices, it is possible to play games on the device's built-in display. Traditionally, when working with a VDT (Visual Display Terminal), which involves sitting in a chair and operating desktop computer devices, protruding the head during operation can put strain on the spine.

[0003] In recent years, the development of mobile information terminals such as smartphones has made it possible for anyone to access any information or enjoy games at any time, anywhere.

[0004] Meanwhile, the health effects of prolonged smartphone use are becoming a concern. Smartphones are often operated while standing or while sitting on a stool or chair. While holding the device in front of the body, users typically operate the device by either lowering the upper arm vertically and keeping only the forearm horizontal, or by resting the elbow on the knee, leaning forward from the upper body to the neck and looking diagonally downward (hereinafter referred to as the "head-down posture"). A head-down posture tends to cause the neck to be thrust forward, contributing to the modern-day condition of "straight neck." According to a preventive medical model study conducted by the Japan Institute of Occupational Health and Safety, an independent administrative institution under the jurisdiction of the Ministry of Health, Labor, and Welfare, using smartphones and other devices tends to result in a head-down posture compared to using a personal computer. Research has shown that the average forward neck tilt angle for healthy neck posture when using a computer is 23±13 degrees, while the average forward neck tilt angle when using a smartphone or other device while standing is 37±14 degrees, indicating a greater degree of head tilt. The forward neck tilt angle is the same angle formed between the line of sight when the forward neck tilt angle is 0 degrees and the line of sight when looking straight ahead while in a head tilted position. In this specification, this angle is referred to as the head tilt angle. It has been reported that the load of the head's weight on the cervical spine doubles when the head is tilted forward by just 2 cm, and fivefold when the head is tilted forward by 4 cm. If this condition continues for a long period of time, it can lead to a condition known as a straight neck.

[0005] Straight neck occurs when a sustained hunched posture places strain on the normally gently curved cervical vertebrae, causing them to lose their curve and become straight, resulting in a chronic protruding head. The gentle curve of the cervical vertebrae distributes the weight of the head across the neck and shoulders, but when you have straight neck, the strain on the neck and shoulders increases, leading not only to stiff shoulders and neck, but also to headaches and dizziness. In today's digital society, where the use of VDT equipment is the norm, it is said that many smartphone and other device users, regardless of age or gender, suffer from straight neck.

[0006] Not only when using smartphones, but also when using a computer at a desk for long periods of time, if you get too close to the display and it becomes difficult to see due to eye fatigue, or if the display is positioned so that your gaze is directed significantly downward rather than horizontally, you may end up in a posture where your neck is thrust forward, which can lead to stiff neck. Musculoskeletal symptoms, including stiff neck, caused by using the displays of information devices, symptoms such as eye fatigue, and other symptoms that affect the whole body and mind are collectively called VDT syndrome.

[0007] Straight neck can be prevented by keeping your back straight, holding your smartphone or other device at eye level, and looking at the display with a small angle of depression, which will allow you to maintain a healthy neck posture without thrusting your neck forward.

[0008] As a prior art for correcting posture, use It has a back support part that supports the thoracic and lumbar transition area of ​​the user, and use Patent Document 1 discloses a chair that stabilizes posture by limiting the contact area with the user's back to around the thoracic-lumbar transition area.

[0009] Furthermore, Patent Document 2 discloses a chair in which the armrests are provided with support for the upper arms and elbows, so that when performing tasks such as typing on a computer keyboard or using a mouse, the elbows can be placed on the armrests and the forearms can be lifted, thereby improving workability by allowing the forearms to have more freedom than when the forearms are placed on the armrests as in the past. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2017-94015 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-78562 Summary of the Invention [Problem to be solved by the invention]

[0011] Incidentally, the onset of straight neck caused by using a smartphone or other device is caused by fatigue in the hands and arms holding the smartphone, which lowers the height of the smartphone, increasing the angle of depression and causing the neck to protrude forward, and cannot be prevented by simply correcting the spine. Considering the mechanism of onset described above, it is difficult to prevent the onset of straight neck with a chair that only has a function to correct the spine, as in Patent Document 1.

[0012] Patent Document 2 discloses that lifting the forearms improves workability and allows the upper arms and elbows to rest on the armrests, thereby relaxing the arms. While keyboard input and mouse operation on a computer are performed on a desk, reducing arm fatigue, using a smartphone or other device requires the elbows to be raised even higher and the hands to be raised until the angle of depression when looking at the display is within 23°±13°. The armrest height of the chair disclosed in Patent Document 2 is not designed for use with smartphones or other devices, so raising the hands to a height that allows the eyes to be level toward the display results in the elbows floating in the air. This increases fatigue throughout the arms, lowering the position of the hands over time, which induces a hunched posture and can lead to the development of a straight neck.

[0013] Furthermore, even when using a personal computer, the display and keyboard are integrated into a laptop computer, so the display height is low and the depression angle is large, making it impossible to prevent the onset of straight neck.

[0014] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a functional chair based on ergonomics that corrects the hunched posture when using desktop or portable computer equipment or when reading, and reduces fatigue in the hands and arms when holding the computer equipment or book, thereby preventing the onset of straight neck. In particular, the present invention aims to provide a functional chair that is effective when using a smartphone or other device without a desk, or when reading. [Means for solving the problem]

[0015] In order to solve the above problems, the functional chair of the present invention is a functional chair that is used when using a desktop or portable computer device and has at least a seat, a backrest, and armrests, The backrest is formed at a height that supports the user from the buttocks to at least the neck, the angle between the seat and the backrest is obtuse, the upper part of the shoulder blades is inclined toward the user and has a gentle curved shape that continues in the height direction, and the height of the upper surface of the armrest is 300 mm to 400 mm from the seat. The sagittal plane refers to a plane that cuts the body symmetrically and a plane that is parallel to the plane.

[0016] In addition, the functional chair of the present invention is This functional chair is used when using desktop or portable computer equipment and has at least a seat, a backrest, and armrests. The backrest is formed at a height that supports at least the user's neck, with an obtuse angle between the seat and the backrest, and has a symmetrical recess in the center of the top surface of the backrest. The height of the upper surface of the armrests is 300 mm to 400 mm above the seat.

[0017] Also, The functional chair of the present invention described in claim 1 or claim 2 is characterized in that the backrest is integrally formed.

[0018] Also, The functional chair of the present invention described in claim 1 or claim 2 is characterized in that the backrest extends integrally, forming a continuous, gentle recess in the central vertical axis direction from the rear lower end of the armrests on both sides to the neck area, and the narrowest point of the recess is narrower than the width of the seat.

[0019] Furthermore, the functional chair of the present invention described in claim 1 or claim 2 is characterized in that the distance between the armrests on both sides gradually and continuously expands from the upper end of the armrest toward the connection with the seat.

[0020] Furthermore, the functional chair of the present invention described in claim 1 or claim 2 is characterized in that the obtuse angle is set to 100 degrees to 110 degrees. [Effects of the Invention]

[0021] According to the functional chair of the present invention, when a user sits and places their elbows on the armrest to read a smartphone or book held in both hands, the angle formed by the upper arm and the vertical line passing through the acromion point is greater than 0 degrees and less than 90 degrees when viewed from the side of the body. This inevitably reduces the user's depression angle to between 10 degrees and 36 degrees. belowThis allows you to place a smartphone or book held in both hands on the table, preventing you from having to keep your head down for long periods of time, which can help prevent the onset of straight neck.The acromion point is the outermost point of the acromion of the scapula.

[0022] Furthermore, with the functional chair of the present invention, by fixing the elbows at a high position, the upper body is supported by the upper arms with the shoulders (acromion point) as a fulcrum, and the posture cannot be tilted any lower than this. Therefore, the chest naturally opens, the shoulder blades close, and the buttocks, spine, and shoulder blades can be brought into contact with the backrest, resulting in the spine forming a natural S-curve and maintaining a healthy neck posture. In other words, as long as a person sits in the functional chair of the present invention with their back in contact with the backrest and their elbows resting on the armrests, a healthy neck posture is maintained and prevented from collapsing when using a smartphone or the like.

[0023] When holding a smartphone or other device with both hands with its longitudinal direction horizontal, the wider the distance between the armrests, the more difficult it is to rest one's elbows on the armrests unless one extends both elbows out to the side. In this case, the height of the smartphone or other device becomes lower, so in order to maintain a healthy neck posture, one must move one's elbows away from the armrests and raise one's hands higher, which causes arm fatigue. According to the functional chair of the present invention, by setting the distance between the buttocks wide and narrowing the distance between the tops of the armrests, users with narrow elbow spacing can rest their elbows on the armrests, achieving the effect of positioning the smartphone or other device within the depression angle considered to be a healthy neck posture. Furthermore, users with narrow elbow spacing can be prevented from lowering their elbows to the inside of the armrests rather than resting them on the armrests.

[0024] On the other hand, when a user is seated, the seated hip width is usually wider than the torso width. The seated hip width is the maximum horizontal diameter of the buttocks measured perpendicular to the sagittal plane. The functional chair of the present invention has the effect of allowing the user to sit comfortably without feeling cramped in the buttocks by gradually expanding from the upper end of the armrest to the point where it connects to the seat. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view of a functional chair 10 according to the present invention. [Figure 2] 1 is a diagram showing a state in which the functional chair 10 according to the present invention is used. [Figure 3] This is a diagram showing the optimal position for operating an ME such as a smartphone while sitting in a chair. [Figure 4] 1 is a side view of a functional chair 10 according to the present invention. [Figure 5] 1 is a front view of a functional chair 10 according to the present invention. [Figure 6] This figure shows the optimal height of the armrest when the acromion height in the sitting position, upper arm length, forearm length, and medial canthus height in the sitting position are at their maximum values ​​in the physical data. [Figure 7] 10 is a diagram showing the optimum height of the armrest 12 when the acromion height in a sitting position, upper arm length, forearm length, and medial canthus height in a sitting position are at their minimum values ​​in the physical data. [Figure 8] This figure shows the state of the armrest 12 at a height of 330 mm when the acromion height, upper arm length, forearm length, and medial canthus height in a sitting position of a young adult are average values. [Figure 9] 1 is a diagram showing the range of optimal heights of the armrest 12 when the acromion height, upper arm length, forearm length, and medial canthus height in a sitting position of a young adult are average values. [Figure 10] This figure shows the state of the armrest 12 at a height of 330 mm when the acromion height, upper arm length, forearm length, and medial canthus height in a sitting position of an elderly person are average values. [Figure 11] 1 is a diagram showing the range of optimal heights of the armrest 12 when the acromion height, upper arm length, forearm length, and medial canthus height in a sitting position of an elderly person are average values. [Figure 12a] This figure shows the optimal height of armrests 1 and 2 when using a desktop computer at a computer desk for young adults with average values ​​for acromion height, upper arm length, forearm length, and medial canthus height in a sitting position. [Figure 12b]This figure shows the optimum height of the armrest 12 when using a laptop computer at a computer desk, for young adults with average values ​​for acromion height, upper arm length, forearm length, and medial canthus height in a sitting position. [Figure 13a] This figure shows the optimal height of the armrest 12 when using a desktop PC at a computer desk for elderly people whose acromion height, upper arm length, forearm length, and medial canthus height in a sitting position are average values. [Figure 13b] This figure shows the optimal height of the armrest 12 when using a laptop computer at a computer desk for elderly people whose acromion height, upper arm length, forearm length, and medial canthus height in a sitting position are average values. [Figure 14] 1 is a perspective view of a chair 20 according to the present invention. [Figure 15] FIG. 10 is a diagram showing a typical chair 81 without armrests in use. [Figure 16] FIG. 1 is a diagram showing a typical armchair 80 in use. [Figure 17a] This is a diagram showing the positional relationship between various parts of the body and armrests 82 when a person with average physical data of a young adult is seated in a typical armchair 80. [Figure 17b] 1 is a diagram showing the positional relationship between various body parts and armrests 82 when a person with average physical data of an elderly person is seated in a typical armchair 80. DETAILED DESCRIPTION OF THE INVENTION

[0026] An embodiment of a functional chair 10 according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the functional chair 10 according to the present invention. The functional chair 10 is intended for use when using desktop or portable computer equipment. In particular, when using a mobile electronic device such as a smartphone, which is frequently used in modern society, it is possible to maintain a healthy posture of the neck 53 and effectively prevent straight neck. The functional chair 10 includes at least a seat 16, a backrest 14, and armrests 12, but FIG. 1 shows the functional chair 10 with legs 18.

[0027] 2 is a diagram showing a functional chair 10 according to the present invention in use. The armrests 12 are shaped so that when a user 50 is seated with their buttocks 60 and back 58 in contact with the backrest 14 and their elbows 56 against the armrests 12, and they are facing a smartphone or other electronic device held in both hands and looking directly at it, the angle formed by the upper arm 55 and a vertical line passing through the acromion 54 is greater than 0 degrees and less than 90 degrees forward in a lateral view (see also FIG. 3). That is, the height from the seat surface 16 to the top surface of the armrest 12 is set higher than that of a normal chair, and the distance from the acromion 54 to the top surface of the armrest 12 is shorter than the length of the upper arm, so that the position where the elbows 56 are placed on the armrests 12 is not further back than the side of the user's 50 body. In addition, by placing the elbow 56 as far forward as possible on the armrest 12, the smartphone or other ME can be placed at a height close to the eye 52, so that instead of a hunched posture, the spine 59 forms a natural S-curve, and a healthy posture of the neck 53 can be maintained.

[0028] First, we will examine healthy postures for the neck when using a smartphone or other ME while seated in a chair. Figures 15 and 16 show postures when using a smartphone or other ME while seated in a typical chair. Figure 15 shows the state of use in a typical chair 81 without armrests. Because there is no stable place to rest elbows 56, the person inevitably assumes a hunched, head-down posture, causing the spine 59 to curve like an arch. When the hand holding the smartphone or other ME becomes tired, the position of the smartphone or other ME moves further downward, such as by resting elbows 56 on the thighs, further increasing the head-down posture and the degree of curvature of the spine 59.

[0029] Figure 16 shows the use of a typical armchair 80. The standard desk height for a computer desk is approximately 700 mm. A computer desk is a desk used for operating tabletop computer equipment, and is used for office work, hobby work, entertainment using electronic devices, competitions, and general sports, including e-sports. Desks for other purposes are often lower than computer desks. To use a chair with armrests 82 with such desks, the armrests 82 are typically set at a height that fits underneath the desk top DS without interfering with it. Therefore, the height from the seat 86, which has a standard height of 400 mm, to the armrests 82 is typically 230 mm or less, subtracting the typical thickness of the desk top DS of 70 mm. In this case, for a person with average body dimensions, when the elbows 56 are lowered on a vertical line passing through the acromion point 54 with an upright posture, i.e., when the elbows 56 are lowered directly from the shoulders, they will not reach the armrests 82.

[0030] Fig. 17a is a diagram showing the positional relationship between each body part and armrest 82 when a person with average physical data of a young adult is seated in a typical armchair 80. Fig. 17b is a diagram showing the positional relationship between each body part and armrest 82 when a person with average physical data of an elderly person is seated in a typical armchair 80.

[0031] For physical data, we used the human body size database published by the National Institute of Advanced Industrial Science and Technology (National Institute of Advanced Industrial Science and Technology AIST Human Body Size Database 1991-92) published by the Artificial Intelligence Research Center. The dimensions required to derive healthy neck posture when using desktop or portable computer equipment are shown in Table 1. [Table 1]

[0032] The acromion height in the sitting position is the height from the seat surface to the acromion point. The medial canthus height in the sitting position is the height from the seat surface to the medial canthus point. The upper arm length is the linear distance from the acromion point to the radial point, i.e., the distance from the shoulder to the elbow of the upper arm. The radial point is the highest point on the superior edge of the radial head when the upper limb is naturally hanging down. The olecranon-to-grip axis distance is the horizontal distance from the posterior edge of the olecranon to the center of the clenched hand. The olecranon-to-grip axis distance is approximately the same length as the length of the forearm 57 (forearm length). The elbow span is the maximum horizontal diameter between the lateral surfaces of the left and right elbows measured perpendicular to the sagittal plane. The hip width is the horizontal diameter of the waist at its widest point when viewed from the front, measured perpendicular to the sagittal plane. Explanations of body-related terms used in this specification are taken from the human body measurement database published by the Artificial Intelligence Research Center of the National Institute of Advanced Industrial Science and Technology.

[0033] When the angle between the seat surface 86 and the backrest 84 is 115 degrees, that is, when the angle of the backrest 84 from the horizontal plane is a typical 75 degrees, in order to view an ME such as a smartphone, the center line from the chest to the head 51 is normally raised so that it faces vertically. If the upper body is reclined at the same angle as the backrest 84, the ME such as a smartphone must be raised higher than the height of the eyes 52, which causes fatigue to accumulate in the arms.

[0034] In Figures 17a and 17b, the upper arm length is shorter than the distance from the acromion point 54 to the armrest, and when the user 50 is seated with their back straight and buttocks 60 to back 58 in contact with the backrest 84, and looks almost directly at an ME such as a smartphone held in both hands, their elbows 56 do not reach the armrest 82.

[0035] If you continue to use a smartphone or other ME in this state, you will bend your body forward, place your elbows 56 on the armrests 82, and look at the display DP with your head down, causing your spine 59 to curve like an arch, as shown in Figure 16. Therefore, if you use a smartphone or other ME while sitting in a regular chair without resting your arms on the desk, you are very likely to develop straight neck.

[0036] A healthy posture for the neck when using a smartphone or other electronic device while seated in a chair will be described with reference to FIG. 3. FIG. 3 is a schematic diagram of the seated state in FIG. 2, excluding the chair. As mentioned above, when leaning the back 58 against the chair back 14, in order to view a smartphone, the center line from the chest to the head 51 is usually raised so that it faces vertically. The healthy posture for the neck 53 when operating a computer while seated in a chair is the aforementioned depression angle of 23±13 degrees. Applying this to FIG. 3, the depression angle for the healthy posture for the neck 53 is a range of 36 degrees from a position rotated 10 degrees counterclockwise from the horizontal direction at the height of the eyes 52. This range will also be adopted as the range of healthy postures for the neck 53 when using a smartphone or other electronic device.

[0037] It can be seen that the distance between the smartphone or other ME and the eyes 52 needs to be about 300 mm for the health of the eyes 52, and therefore the position of the elbows 56 needs to be placed at a position considerably higher than the seat surface. When the elbows 56 are on a vertical line drawn from the acromion point 54, it is clearly difficult to position the smartphone or other ME within a depression angle range of 23±13 degrees.

[0038] The eye 52 can move its line of sight up and down without changing the angle of the neck. The eyeball has a field of view of approximately 120 degrees, meaning it can see without moving. However, there are portions of the upper and lower limits of approximately 30 degrees that cannot be accurately viewed. Taking all of this into consideration, the entire smartphone or other ME does not need to be within the hatched area in Figure 3. As long as the center of the smartphone or other ME is on the boundary line, it is possible to view everything displayed on the display DP by maintaining the depression angle within a range of 23±13 degrees.

[0039] FIG. 4 is a side view of the functional chair 10 according to the present invention. User 50The backrest 14 is set at a height that supports the user's buttocks 60 to at least the neck 53, with an obtuse angle between the seat surface 16 and the backrest 14. Above the upper shoulder blades, the backrest 14 is tilted toward the user 50, forming a gently curved shape in the height direction. The angle of the backrest 14 from the buttocks 60 to the back 58 is set to 100 to 110 degrees, similar to the angle of the backrest 14 of a typical computer chair, i.e., the angle of the backrest 14 from the buttocks 60 to the back 58 is set to 70 to 80 degrees from the horizontal. Since the centerline of the backrest 14 above the upper shoulder blades is normally vertical, as described above, the backrest 14 is tilted toward the user 50, approximately ±5 degrees from the vertical, so that it can fit along the upper body. The shape of the backrest 14 reduces fatigue when sitting for long periods of time and using a mobile device such as a smartphone. On the other hand, when using an ME such as a smartphone, the height from the seat surface 16 to the top surface of the armrest 12 is an especially important condition, which will be described in detail later.

[0040] 5 is a front view of a functional chair 10 according to the present invention. The distance between the armrests 12 installed on both the left and right sides gradually increases from the upper ends of the armrests 12 to the points where they connect to the seat surface 16. As an example, the distance between the upper ends of the armrests 12 is User 50The elbow-to-elbow distance is set to 380 mm, shorter than the average elbow-to-elbow distance of 400 mm (see Table 1). This is because if the armrest spacing is too wide, the user 50 will lower their elbows 56 rather than resting them on the armrests. The longitudinal dimension of current smartphones is approximately 100 mm to 150 mm. Therefore, when the smartphone is held with both hands with its longitudinal direction horizontal, resting the elbows 56 on both armrests will result in both elbows 56 protruding sideways. In this case, the wider the spacing between the armrests, the more the user must protrude both elbows 56 sideways to place them on the armrests, forcing the hands holding the smartphone to move downward. In this case, the user's gaze is forced to angle downward from the horizontal, increasing the angle of depression and resulting in a hunched posture that can cause a straight neck. To maintain a healthy neck posture when using a smartphone, the user must keep their elbows 56 away from the armrests, which causes fatigue in the arms. According to the functional chair 10 of the present invention, by setting the distance between the armrests 12 at the waist area wide and narrowing the distance between the tops of both armrests 12, a user 50 with narrow elbow spacing can place their elbows 56 on the armrests 12 with less of their elbows sticking out to the side, and can position the smartphone or other electronic device within the angle of depression, which is considered to be a healthy posture for the neck when using it. Also, it prevents users 50 with narrow elbow spacing from placing their elbows 56 on the inside of the armrests 12 instead of placing them on the armrests 12. Meanwhile, the average hip width in the sitting position is about 340 mm (see Table 1), but the maximum value is 413 mm, making it suitable for all body types. User 50 In one example, the distance between the armrests 12 where they connect to the seat surface 16 is set to 430 mm so that a user 50 can sit comfortably. If the functional chair 10 according to the present invention has a function that allows the distance between the armrests 12 to be widened or narrowed according to the physique, it can be applied to users 50 with extremely large body sizes and users 50 who are small children, and is therefore suitable. The distance between the upper ends of the armrests 12 and the distance between the armrests 12 where they connect to the seat surface 16 shown above are merely examples and are not limited thereto. It is sufficient that the distance between the upper ends of the armrests 12 is narrowed so that the elbows 56 do not hang down from the armrests 12, and that the distance between the lower ends of the armrests 12 is wider than the upper ends so that the buttocks 60 do not feel cramped.

[0041] When using a smartphone or other ME while seated in a chair, the height from the seat surface 16 to the top of the armrest 12 is an important condition for maintaining a head depression angle within the range of 23±13 degrees, which is considered to be a healthy posture for the neck. The following is a study to determine the height from the seat surface 16 to the top of the armrest 12 (hereinafter, "the height from the seat surface to the top of the armrest" will be referred to as "armrest height").

[0042] First, using physical data, the optimal height of the armrest was confirmed when the acromion height in the sitting position, upper arm length, forearm length, and medial canthus height in the sitting position were at their maximum and minimum values. Figure 6 is a diagram showing the optimal height of the armrest when the acromion height in the sitting position, upper arm length, forearm length, and medial canthus height in the sitting position are at their maximum values ​​using physical data. When the data for the acromion height in the sitting position, upper arm length, forearm length, and medial canthus height in the sitting position are at their maximum values, in order to turn the gaze slightly downward and maintain the depression angle within the range of 23±13 degrees, the height of the armrest 12 should be between 330 mm and 450 mm. below It can be seen that the depression angle is within the range of 23±13 degrees. Note that eye 52 can move its line of sight up and down without changing the angle of neck 53. Also, it has a field of view of approximately 120 degrees. Therefore, it is not necessary for the entire ME such as a smartphone to be positioned at an angle of 10 degrees to 36 degrees counterclockwise from the horizontal direction centered on eye 52. As long as the center of the ME such as a smartphone is on the boundary line, it is possible to view the entire display DP by maintaining the depression angle within the range of 23±13 degrees.

[0043] On the other hand, Figure 7 is a diagram showing the optimum height of the armrest 12 when the acromion height, upper arm length, forearm length, and medial canthus height in the sitting position are at their minimum values, using body data. When the data for the acromion height, upper arm length, forearm length, and medial canthus height in the sitting position are at their minimum values, the height of the armrest 12 must be between 230 mm and 330 mm in order to keep the angle of depression within the range of 23±13 degrees with the gaze slightly downward. below As mentioned above, it is not necessary for the entire ME such as a smartphone to be positioned at an angle of 10 degrees or more and 36 degrees or less counterclockwise from the horizontal direction with the eye 52 as the center.

[0044] When the acromion height in the sitting position, upper arm length, forearm length, and medial canthus height in the sitting position are at their maximum and minimum values, the common height of the armrest 12 is 330 mm, which is found to be the optimum value.

[0045] Furthermore, we confirmed the height of the armrest 12 that maintains a healthy neck posture when the acromion height, upper arm length, forearm length, and medial canthus height in a seated position are average values. The average values ​​of the human body dimension data published by the National Institute of Advanced Industrial Science and Technology (AIST)'s Artificial Intelligence Research Center are shown for young adults and elderly people, so we conducted separate studies. Figure 8 shows the armrest 12 height of 330 mm when the acromion height, upper arm length, forearm length, and medial canthus height in a seated position for a young adult are average values. It can be seen that a smartphone or other mobile device is positioned within a head depression angle range of 23±13 degrees.

[0046] Next, using the average values ​​of the physical data of young adults, we confirmed the height of the armrest 12 that would allow a smartphone or other ME to be placed within a depression angle range of 23±13 degrees. Figure 9 is a diagram showing the range of optimal heights for the armrest 12 when the acromion height, upper arm length, forearm length, and medial canthus height in a sitting position of young adults are average values. It can be seen that in order to place and maintain a smartphone or other ME within a depression angle range of 23±13 degrees, the height of the armrest 12 should be within the range of 307 mm to 440 mm.

[0047] Next, we confirmed the optimal height of the armrest 12 for the average values ​​of the elderly person's physical data. First, Figure 10 shows the state when the armrest 12 is at a height of 330 mm when the elderly person's acromion height, upper arm length, forearm length, and medial canthus height in a sitting position are average values. It can be seen that the smartphone or other ME is positioned within a depression angle range of 23±13 degrees.

[0048] Next, we confirmed the height of the armrest 12 that allows an ME such as a smartphone to be placed within a depression angle range of 23±13 degrees for the average physical data of elderly people. Figure 11 is a diagram showing the range of optimal heights for the armrest 12 when the acromion height, upper arm length, forearm length, and medial canthus height in a sitting position of elderly people are average values. It can be seen that in order to place and maintain an ME such as a smartphone within a depression angle range of 23±13 degrees, the height of the armrest 12 should be within the range of 275 mm to 390 mm.

[0049] Considering both young adults and elderly people, the range of armrest 12 heights that can maintain a healthy neck posture for young adults is 307 mm to 440 mm. The range of armrest 12 heights that can maintain a healthy neck posture for elderly people is 275 mm to 390 mm. Of these ranges, the common range of 307 mm to 390 mm is found to be the preferred range for armrest 12 heights that can be applied to both young adults and elderly people. Furthermore, the eyes 52 can move their gaze up and down without changing the angle of the neck 53. Furthermore, since a person has a visual field of approximately 120 degrees, the height of the armrest 12 that can maintain a depression angle of 23±13 degrees, which is considered a healthy neck posture, can be expanded by approximately 10 mm to 300 mm to 400 mm. [Example]

[0050] Figure 12a shows the optimal height of the armrest 12 when using a desktop computer at a computer desk for a young adult with average values ​​for acromion height, upper arm length, forearm length, and medial canthus height. The seat height from the floor when using desktop computer equipment is generally set to approximately 360 mm to 450 mm, with an average of 400 mm. The height of the top surface of the computer desk's top plate DS, including those equipped with height adjusters on the bottom of the legs, is set to approximately 650 mm to 750 mm, with an average of 700 mm. The functional chair 10 of the present invention, with the armrest 12 set to a height of 330 mm, was applied to the computer desk and examined. The height of the armrest 12 is approximately 30 mm higher than the computer desk top plate DS. When placing the palm of the hand on the computer desk top plate DS, the thickness of the palm allows the fingers to approach the keyboard KB horizontally, reducing fatigue even during prolonged use.

[0051] If the display DP is positioned so that its center is tilted 23 degrees counterclockwise from the horizontal, with the eye 52 at the center, and the distance between the eye 52 and the display DP is at least 400 mm for a standard display DP and at least 500 mm for a widescreen display, which are generally considered appropriate, the elbow 56 will be positioned forward of the body as shown in the figure. In this case, the head 51 is difficult to move forward because the elbow 56 is placed on the armrest 12 and the upper body is supported by the upper arm 55, with the shoulder as the fulcrum. If the elbow 56 is moved forward, the shoulder moves forward and the head 51 moves forward, resulting in a head-down posture. However, at the same time, the fingers also move forward, making it impossible to type. Therefore, the elbow 56 cannot be extended forward. It is also possible to assume a head-down posture by shrugging the shoulders and thrusting the upper body forward, but this becomes very uncomfortable and makes it difficult to maintain the same posture for long periods of time. Therefore, the depression angle can be maintained within the range of 23±13 degrees, preventing the patient from assuming a hunched posture and maintaining a healthy posture for the neck.

[0052] Figure 12b shows the optimum height of the armrest 12 when using a laptop computer at a computer desk, assuming that the acromion height, upper arm length, forearm length, and medial canthus height in a sitting position of a young adult are average values. As in Figure 12a, the height of the armrest 12 was set to 330 mm. In a laptop computer, the display DP is connected to the keyboard KB, so the height of the display DP must be lower than that of a desktop computer, which makes it difficult for the operator to sit comfortably. 12b, it can be seen that the display DP can be positioned so that the depression angle is within the range of 23±13 degrees. The height of the armrest 12 in this embodiment is just an example, and the same effect can be achieved if the height is set so that the elbow 56 is positioned forward of the body.

[0053] Figure 13a shows the range of optimal armrest heights (12) when using a computer desk for elderly people with average values ​​of acromion height, upper arm length, forearm length, and medial canthus height (sitting position). The computer desk is as described above. The functional chair 10 of the present invention, with the armrest 12 set to a height of 330 mm, was applied to the computer desk. The height of the armrest 12 is approximately 30 mm higher than the computer desk top (DS). When placing the palm of the hand on the computer desk top (DS), the thickness of the palm allows the fingers to approach the keyboard (KB) horizontally, just like a young adult. The difference is that the keyboard (KB) is slightly closer to the body due to differences in upper arm and forearm lengths.

[0054] If the display DP is positioned so that its center is tilted 23 degrees counterclockwise from the horizontal, with the eye 52 at the center, and the distance between the eye 52 and the display DP is kept within the generally accepted range, the elbow 56 will be positioned forward, as shown in the figure. In this case, the person places the elbow 56 on the armrest 12, as in the case of a young adult, and supports the upper body with the shoulder as a fulcrum using the upper arm 55, making it difficult for the head 51 to move forward. If the elbow 56 is moved forward, the shoulder moves forward, and the head 51 moves forward, resulting in a head-down posture. However, at the same time, the fingers also move forward, preventing keyboard input, making it impossible to move the elbow 56 forward. It is also possible to assume a head-down posture by thrusting the upper body forward as if shrugging the shoulders, but this is extremely uncomfortable and makes it difficult to maintain the same posture for long periods of time. Therefore, the head-down angle can be maintained within the range of 23±13 degrees, preventing the person from assuming a head-down posture and maintaining a healthy neck posture.

[0055] Figure 13b shows the optimal height of the armrest 12 when using a laptop computer at a computer desk for elderly people with average values ​​for acromion height, upper arm length, forearm length, and medial canthus height. As in Figure 13a, the height of the armrest 12 was set to 330 mm. Because the display DP of a laptop computer is connected to the keyboard KB, the display DP must be lower than that of a desktop computer, causing the operator to tilt their head down more. However, Figure 13b shows that the display DP can be positioned within a depression angle of 23±13 degrees. The height of the armrest 12 in this embodiment is merely an example; the same effect can be achieved by setting the armrest 12 at a height that positions the elbow 56 forward of the body. [Example]

[0056] FIG. 14 is a perspective view of a seat 20 according to the present invention. It does not have legs, allowing it to be used in a Japanese-style room. In a Japanese-style room, the user can stretch out their legs and move their buttocks 60 forward. However, the seat 20 of the present invention is preferably set to a height of 300 mm to 400 mm from the seat surface 26 to the top of the armrest 22. Because this height is higher than that of a typical chair, the position of the acromion point 54 is lowered. If it is lower than the height of the armrest 22, the angle formed by the upper arm 55 and the vertical line passing through the acromion point 54 exceeds 90 degrees. This causes the smartphone or other ME to be positioned higher than the eye 52 by the length of the forearm, causing the user to look diagonally upward from the horizontal, resulting in significant fatigue. Therefore, the user naturally sits with the buttocks 60 and back 58 in contact with the backrest 24, allowing the spine 59 to form a natural S-curve, maintaining a healthy neck posture. According to the chair 20 of the present invention, even when sitting directly on the tatami mat in a Japanese-style room and using an electronic device such as a smartphone, it is possible to correct a hunched posture and prevent the onset of straight neck. [Industrial Applicability]

[0057] The present invention is not limited to personal computers, game consoles that use displays, and portable game consoles, Ergonomic posture when using or reading mobile information devices such as smartphones and tablets This will be used in chairs with functionality to prevent smart neck and maintain a healthy posture for the neck. is possible. [Explanation of symbols]

[0058] 10 Functional chairs 12 Armrests 14 Backrest 16 seat 18 legs 20 Chair 22 Armrest 24 Backrest 26 Seat 50 users 51 Head 52 eyes 53 Neck 54 Acromial point 55 Upper Arm 56 Elbow 57 Forearm 58 Back 59 Spine 60 Buttocks 80 General armchair 81 General chair without armrests 82 Armrest 84 Backrest 86 seat DS top plate ME smartphone etc. DP Display KB Keyboard

Claims

1. A functional chair having at least a seat, a backrest, and armrests for use when using desktop or portable computer equipment, The backrest, It is formed to a height that supports the user's buttocks to at least the neck, The angle between the seat surface and the backrest is an obtuse angle, and the seat has a gentle curved shape that is inclined toward the user above the upper part of the shoulder blades and continues in the height direction, The armrest upper surface height is Between 300mm and 400mm from the seat surface, A functional chair characterized by its functionality.

2. A functional chair having at least a seat, a backrest, and armrests for use when using desktop or portable computer equipment, The backrest, The angle between the seat surface and the backrest is an obtuse angle, and the backrest is formed to a height that supports at least the neck of the user. The backrest has a recess in a symmetrical shape at the center of the top surface. The armrest upper surface height is Between 300mm and 400mm from the seat surface, A functional chair characterized by its functionality.

3. The backrest, integrally formed, 3. The functional chair according to claim 1 or 2.

4. The backrest, Between the rear lower ends of the armrests on both sides and the neck area, a continuous gentle recess is formed in the central vertical axis direction and extends integrally, The narrowest point of the recess is Narrower than the width of the seat 3. The functional chair according to claim 1 or 2.

5. The distance between the armrests on both sides is The armrest extends gradually and continuously from the upper end thereof to the connecting portion with the seat surface.

3. The functional chair according to claim 1 or 2.

6. The obtuse angle is It is set at 100 to 110 degrees. A functional chair according to claim 1 or claim 2.

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