This application claims foreign priority to Japanese Patent Application No. 2014-122356 filed with the Japan Patent Office on Jun. 13, 2014, the entire contents of which are incorporated herein by reference.
1. Field
The present invention relates to an electromagnetic relay (relay). Specifically, the present invention relates to a relay having a function of displaying a light emitting operation.
2. Related Art
In some conventional relays, an operation indicating lamp is provided in the relay in order that a worker easily checks an operation of the relay. The operation indicating lamp is lit or turned off in conjunction with opening and closing operations of the relay. Generally, in order to facilitate visual recognition of a lighting state of the operation indicating lamp from the outside, there is a demand for easily seeing light of the operation indicating lamp on an opposite side to a bottom surface that is of a relay attaching surface, namely, on a side of a case top surface. For this purpose, it is conceivable that the operation indicating lamp is vertically arranged in a case with respect to the case top surface. At the same time, there is also demand for the compact relay. Therefore, a space in the case in which the operation indicating lamp is arranged is restricted, and the operation indicating lamp is horizontally arranged to make the compact relay in the case that there is no space in the case in which the operation indicating lamp is arranged.
For example, in a relay disclosed in Japanese Patent No. 4319973, a light guide path that extends vertically along a side surface of a case (housing) is provided outside the case. The top surface of the light guide path is located at the same level as the top surface of the case, and constitutes a display surface of the light guide path. The light horizontally emitted from a light source (lighting unit) horizontally provided in the case is input to the light guide path from a lower end portion of the light guide path, reflected toward the case top surface by a reflecting surface, guided in the light guide path, and output from the display surface that is of the top surface of the light guide path. As a result, when the light source is lit, the display surface of the light guide path glows on the top surface of the relay.
In a relay disclosed in Unexamined Japanese Utility Patent Publication No. S54 (1979)-183658, the light guide path (light output body) is provided in the relay, the light source faces a lower end face of the light guide path, and a lens is provided in an upper end face of the light guide path.
However, in the relay disclosed in Japanese Patent No. 4319973, the light output from the display surface has poor uniformity, and the light output from the display surface has narrow directivity angle. For this reason, even if the display surface glows while the light source is lit, visibility degrades when the relay is observed in an oblique direction (a direction oblique to a direction perpendicular to the top surface of the relay). Particularly, in the case that many relays are attached to a control panel, it is necessary to observe the individual relay in the direction perpendicular to the top surface and to move a head portion sequentially along an array of the relays in order to check the lighting state of the relay, which results in a troublesome work.
In the relay disclosed in Japanese Patent No. 4319973, a diffused reflection surface is provided around the display surface by roughening the top surface of the case. The diffused reflection surface improves the visibility of the display surface by scattering the light leaking from the surroundings of the display surface. The diffused reflection surface is provided at a position deviating from an optical path of the light output from the display surface, and little light leaks from the side surface of the light guide path. Therefore, the diffused reflection surface is of a degree to which the state of the display surface can be highlighted when the display surface is viewed from a front. In the diffused reflection surface, it is difficult to clearly recognize the lighting state of the light source when the light source is viewed in the oblique direction.
The lens disclosed in Unexamined Japanese Utility Patent Publication No. 54(1979)-183658 is not a diffusing lens but a collecting lens. Accordingly, even in the relay disclosed in Unexamined Japanese Utility Patent Publication No. 54(1979)-183658, the lighting state of the light source can easily be recognized in the direction perpendicular to the top surface, while the lighting state of the light source can hardly be recognized in the oblique direction.
One or more embodiments of the present invention provides a compact operation-indicating-lamp-equipped electromagnetic relay in which the lighting of the light source (operation indicating lamp) can easily visually be recognized even in the oblique direction.
According to one or more embodiments of the present invention, an operation indicating lamp-equipped electromagnetic relay configured to open and close a circuit by electromagnetic interaction between an excitation coil and a contact member, the operation indicating lamp-equipped electromagnetic relay includes: a housing configured to accommodate the excitation coil and the contact member therein; a light source including an optical axis that is oriented toward a direction other than a display surface arranged in a top surface of the housing in order to display an operating situation of the electromagnetic relay, the light source being accommodated in the housing so as to emit light according to a situation of power supplied to the excitation coil; and a reflecting member accommodated in the housing so as to reflect the light emitted from the light source toward the display surface. At this point, a diffusion structure configured to diffuse the light reflected by the reflecting member is formed in the display surface.
The reflecting member reflects the light emitted from the light source toward the display surface arranged on the top surface of the housing. The light reflected by the reflecting member is diffused by the diffusion structure formed on the display surface. Therefore, the uniformity and directionality of the light output from the display surface can further be improved. Accordingly, the visibility is improved when the housing of the electromagnetic relay is observed from obliquely above. As a result, the compact operation-indicating-lamp-equipped electromagnetic relay in which the lighting of the light source is easily visually recognized even in the oblique direction can be provided.
In the operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention, the reflecting member reflects the light emitted from the light source to propagate in air.
According to the configuration, by a simple combination of the reflecting member and the diffusion structure, the visibility can be enhanced when the housing of the electromagnetic relay is observed from obliquely above.
An operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention further includes a light guide unit configured to guide the light reflected by the reflecting member to the display surface. At this point, the reflecting member reflects the light emitted from the light source to propagate in air, and the light guide unit includes a side surface configured to totally reflect the reflected light to guide the totally-reflected light to the display surface.
According to the configuration, the light reflected by the reflecting member is totally reflected by the side surface of the light guide unit, and guided to the display surface. As a result, an outline of the display surface is clearly viewed when the housing of the electromagnetic relay is observed from obliquely above.
An operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention further includes a light guide unit configured to guide the light reflected by the reflecting member to the display surface. At this point, the reflecting member is integrated with the light guide unit, and the reflecting member includes a total reflection surface arranged so as to totally reflect the light emitted from the light source to guide the totally-reflected light to the display surface.
According to the configuration, the light totally reflected by the total reflection surface of the reflecting member is totally reflected by the side surface of the light guide unit, and guided to the display surface. As a result, an outline of the display surface is clearly viewed when the housing of the electromagnetic relay is observed from obliquely above.
In the operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention, the reflecting member reflects the light emitted from the light source to propagate in air, and a diffuse reflection structure configured to diffusely reflect the light is formed in the reflecting member, the light being emitted from the light source to propagate in air.
According to the configuration, the diffuse reflection structure is formed in the reflecting member while the diffusion structure is formed in the display surface, so that the uniformity and directionality of the light output from the display surface can further be improved.
An operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention further includes a light guide unit configured to guide the light reflected by the reflecting member to the display surface. At this point, a diffuse reflection structure configured to diffusely reflect the light is formed in the reflecting member, the light being emitted from the light source to propagate in air.
According to the configuration, the diffuse reflection structure is formed in the reflecting member while the diffusion structure is formed in the display surface, so that the uniformity and directionality of the light output from the display surface can further be improved.
An operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention further includes a light guide unit configured to guide the light reflected by the reflecting member to the display surface. At this point, a diffuse reflection structure configured to diffusely reflect the light is formed in the reflecting member, the light being emitted from the light source to propagate in air, the reflecting member is integrated with the light guide unit, the reflecting member includes a total reflection surface arranged so as to totally reflect the light emitted from the light source to guide the totally-reflected light to the display surface, and the diffuse reflection structure is formed in the total reflection surface.
According to the configuration, the diffuse reflection structure is formed in the total reflection surface of the reflecting member while the diffusion structure is formed in the display surface, so that the uniformity and directionality of the light output from the display surface can further be improved.
An operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention further includes a holder accommodated in the housing so as to hold the light emitting diode and the reflecting member. At this point, the light source is a light emitting diode, the holder holds the light emitting diode such that an optical axis of the light emitting diode is oriented toward the direction other than the display surface, and the holder is formed so as to cover a top surface side of the light emitting diode.
According to the configuration, the light emitting diode is arranged in the direction parallel to the display surface by the simple configuration, so that the compact electromagnetic relay can be made. Because the holder shields the light that is directly oriented from the light emitting diode toward the display surface, the light is output only from the region of the display surface. Accordingly, only the shape of the display surface that outputs the light can visually be recognized.
According to one or more embodiments of the present invention, an operation indicating lamp-equipped electromagnetic relay configured to open and close a circuit by electromagnetic interaction between an excitation coil and a contact member, the operation indicating lamp-equipped electromagnetic relay includes: a housing configured to accommodate the excitation coil and the contact member therein; a light source including an optical axis that is oriented toward a direction other than a display surface arranged in a top surface of the housing in order to display an operating situation of the electromagnetic relay, the light source being accommodated in the housing so as to emit light according to a situation of power supplied to the excitation coil; and a reflecting member accommodated in the housing so as to reflect the light emitted from the light source toward the display surface. At this point, a diffuse reflection structure configured to diffusely reflect the light emitted from the light source is formed in the reflecting member.
The light emitted from the light source is diffusely reflected by the diffuse reflection structure formed in the reflecting member, and guided to the display surface. Therefore, the uniformity and directionality of the light output from the display surface can further be improved. Accordingly, the visibility is improved when the housing of the electromagnetic relay is observed from obliquely above. As a result, the compact operation-indicating-lamp-equipped electromagnetic relay in which the lighting of the light source is easily visually recognized even in the oblique direction can be provided.
In an operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention, the diffuse reflection structure diffusely reflects the light, emitted from the light source to propagate in air, to guide the diffusely-reflected light to the display surface.
According to the configuration, by a simple combination in which the diffuse reflection structure is formed in the reflecting member, the visibility can be enhanced when the housing of the electromagnetic relay is observed from obliquely above.
An operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention further includes a light guide unit configured to guide the light diffusely reflected by the diffuse reflection structure to the display surface. At this point, the light guide unit includes a side surface configured to totally reflect the diffusely-reflected light to guide the totally-reflected light to the display surface.
According to the configuration, the light diffusely reflected by the diffuse reflection structure formed in the reflecting member is totally reflected by the side surface of the light guide unit, and guided to the display surface. As a result, an outline of the display surface is clearly viewed when the housing of the electromagnetic relay is observed from obliquely above.
An operation indicating lamp-equipped electromagnetic relay according to one or more embodiments of the present invention further includes a light guide unit configured to guide the light diffusely reflected by the diffuse reflection structure to the display surface. At this point, the reflecting member is integrated with the light guide unit, the reflecting member includes a total reflection surface arranged so as to totally reflect the light emitted from the light source to guide the totally-reflected light to the display surface, and the diffuse reflection structure is formed in the total reflection surface.
According to the configuration, the light diffusely reflected by the diffuse reflection structure formed in the total reflection surface of the reflecting member is further totally reflected by the side surface of the light guide unit, and guided to the display surface. As a result, an outline of the display surface is clearly viewed when the housing of the electromagnetic relay is observed from obliquely above.
The diffusion structure that diffuses the light reflected by the reflecting member is formed in the display surface, so that one or more embodiments of the present invention provides a compact operation-indicating-lamp-equipped electromagnetic relay in which the lighting of the light source can easily visually be recognized even in the oblique direction.
Hereinafter, exemplary embodiments of the present invention will be described in detail. In embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid obscuring the invention.
(Configuration of Relay Body 14)
In the relay 1, a relay body 14 and a shell-type operation indicating lamp (light source) 8 constructed with a Light Emitting Diode (LED) are incorporated in a rectangular parallelepiped case (housing) 2. The case 2 is constructed with a base 2d made of an opaque resin and a housing 2c made of a transparent resin.
The relay body 14 having a structure in
Plural movable contact springs 20 are attached in parallel to a front surface of the armature 15 by a support 19. Plural common terminals 21, plural normally closed terminals 22, and plural normally opened terminals 23 are inserted in the base 2d so as to vertically pierce the base 2d. An upper end of each movable contact spring 20 is electrically connected to the corresponding common terminal 21 by a cable line 24. A lower end portion of the movable contact spring 20 is located between an upper end portion of the normally closed terminal 22 and an upper end portion of the normally opened terminal 23, and movable contacts (contact member) 25 are provided on both surfaces of the lower end portion of the movable contact spring 20. A normally closed contact (contact member) 26 is provided in the upper end portion of each normally closed terminal 22 so as to face the movable contact 25 in front of the movable contact 25. A normally opened contact (contact member) 27 is provided in the upper end portion of each normally opened terminal 23 so as to face the movable contact 25 at the back of the movable contact 25.
In the relay body 14, in the case that the coil unit 3 is not excited, because the lower portion of the armature 15 is located in front of the iron core while separating from the iron core, a lower portion of the movable contact spring 20 also moves forward. Therefore, in this state, the movable contact 25 contacts with the normally closed contact 26 to electrically connect the common terminal 21 and the normally closed terminal 22 to each other, and the movable contact 25 separates from the normally opened contact 27 to electrically disconnect the common terminal 21 and the normally opened terminal 23 to each other.
When the coil unit 3 is excited, the lower portion of the armature 15 is attracted to the iron core to move rearward, and the lower portion of the movable contact spring 20 also moves rearward. Therefore, the movable contact 25 contacts with the normally opened contact 27 to electrically connect the common terminal 21 and the normally opened terminal 23 to each other, and the movable contact 25 separates from the normally closed contact 26 to electrically disconnect the common terminal 21 and the normally closed terminal 22 to each other.
The housing 2c is a molding project made of a high-refractive-index transparent resin such as a polycarbonate resin. Alternatively, the housing 2c may be a molding project made of a semi-transparent resin or a colored transparent resin. In such cases, desirably the semi-transparent resin having a higher transparency and the colored transparent resin having a paler color are used such that an inside of the relay 1 is checked.
(Configuration of LED Holder 7)
The operation indicating lamp 8 is fitted in a recess 7b provided in an end portion of the LED holder 7, and held by the LED holder 7. The LED holder 7 is fixed to the top surface of the yoke 16 (
A light shielding roof 7c and a bottom output unit (reflecting member) 10 are provided in the LED holder 7. The light shielding roof 7c is formed between a top surface 2a of the case 2 and the operation indicating lamp 8 so as to cover the operation indicating lamp 8. The bottom output unit (reflecting member) 10 reflects the light emitted from the operation indicating lamp 8, and guides the light to a square top output unit (display surface) 2b arranged on the top surface 2a of the case 2. Because the light shielding roof 7c is formed in the LED holder 7 as a measure against light leakage from the operation indicating lamp 8, the operation indicating lamp 8 is fitted in the recess 7b of the LED holder 7 from below.
(Configuration of Operation Indicator of First Embodiment)
The operation indicating lamp 8 is held by the LED holder 7 such that an optical axis of the operation indicating lamp 8 is oriented toward a direction parallel to the top surface 2a of the case 2. As used herein, the term “optical axis” means an axis along the direction in which intensity of the light emitted from the light source (operation indicating lamp 8) becomes the maximum. The light is emitted from the operation indicating lamp 8 with the largest intensity in the direction along the optical axis. However, the light is emitted in not only the direction of the optical axis, but all directions. Accordingly, the light oriented toward the top surface 2a can exist even if the operation indicating lamp 8 is arranged in parallel to the top surface 2a.
The operation indicating lamp 8 is not necessarily arranged such that the optical axis of the operation indicating lamp 8 is oriented toward the direction parallel to the top surface 2a of the case 2. Even if the optical axis of the operation indicating lamp 8 is slightly deviated from the direction parallel to the top surface 2a, the operation indicating lamp 8 can be accommodated in a housing of the electromagnetic relay to contribute the compact electromagnetic relay when the operation indicating lamp 8 is arranged such that the optical axis direction is oriented toward the direction other than the display surface on the top surface of the case.
According to a situation of power supplied to the coil unit 3, the operation indicating lamp 8 outputs the light with the maximum intensity toward the bottom output unit 10 of the LED holder 7 in parallel to the top surface 2a of the case 2. The bottom output unit 10 has the opaque configuration, and regularly reflects the light, which is emitted from the operation indicating lamp 8 to propagate in air, toward the top output unit 2b.
The opaque configuration of the bottom output unit 10 may be made of a non-transparent material, or a reflection surface may be provided in at least a part of a transparent material to implement a non-transparent state. As used herein, the term “transparent” means a small absorption ratio of the light emitted from the light source (operation indicating lamp 8) in a material.
The diffusion structure 12 formed in the top output unit 2b diffuses the light reflected by the bottom output unit 10. The light shielding roof 7c shields the light that is output from the operation indicating lamp 8 toward the top surface 2a of the case 2.
Because the diffusion structure 12 is formed in the top output unit 2b, the uniformity and directionality of the light output from the top output unit 2b can further be improved. Therefore, the visibility is improved when the housing 2 of the relay 1 is observed from obliquely above. Particularly, the trouble of sequentially moving a head position along an array of the relays is eliminated because the lighting states of many relays attached to control panel can be checked from obliquely above.
The light shielding roof 7c shields the light that is output from the operation indicating lamp 8 toward the top surface 2a, so that only the square top output unit 2b that outputs the light reflected by the bottom output unit 10 can visually be recognized. When a white is selected as a color of the LED holder 7, the bottom output unit 10 can reflect any color light output from the operation indicating lamp 8.
(Configuration of Another Operation Indicator of First Embodiment)
A light guide (light guide unit) 11 that guides the light output from the bottom output unit 10 to the top output unit 2b is formed below the top output unit 2b so as to project from the case 2 toward the bottom output unit 10. A side surface 11a is formed in the light guide 11. The side surface 11a totally reflects the light reflected by the bottom output unit 10, and guides the totally-reflected light to the top output unit 2b. A section of the light guide 11 is formed into a square shape corresponding to the square top output unit 2b.
The operation indicating lamp 8 emits the light toward the bottom output unit 10 of the LED holder 7 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The bottom output unit 10 regularly reflects the light, which is emitted from the operation indicating lamp 8 to propagate in air, toward the light guide 11. The light regularly reflected by the bottom output unit 10 is incident on the light guide 11, totally reflected by the side surface 11a of the light guide 11, and guided to the top output unit 2b. The diffusion structure 12 formed in the top output unit 2b diffuses the light regularly reflected by the bottom output unit 10 and the light totally reflected by the side surface 11a.
Because the light guide 11 is added to the configuration in
(Configuration of Still Another Operation Indicator of First Embodiment)
A total reflection light guide (a reflecting member and a light guide unit) 13 is formed below the top output unit 2b so as to project from the case 2 toward the inside of the case 2. A total reflection surface 13a, which totally reflects the light emitted from the operation indicating lamp 8 and guides the totally-reflected light to the top output unit 2b, is formed in the total reflection light guide 13. A section of the total reflection light guide 13 is formed into a square shape corresponding to the square top output unit 2b. The bottom output unit 10 in
The operation indicating lamp 8 emits the light toward the total reflection light guide 13 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The light emitted from the operation indicating lamp 8 is incident on the total reflection light guide 13, and totally reflected by the total reflection surface 13a. The light totally reflected by the total reflection surface 13a is partially guided to the top output unit 2b. The remaining totally-reflected light is totally reflected by the side surface of the total reflection light guide 13, and guided to the top output unit 2b. The diffusion structure 12 formed in the top output unit 2b diffuses the light guided to the top output unit 2b.
Because the total reflection light guide 13 is provided, the light totally reflected by the total reflection surface 13a of the total reflection light guide 13 is further totally reflected by the side surface (the interface with the air layer) of the total reflection light guide 13. Therefore, the light incident on the total reflection light guide 13 is uniformed, and the light is guided to the top output unit 2b while confined in the square section of the total reflection light guide 13. As a result, compared with the configuration in
An interval in which the light is confined in the total reflection light guide 13 is longer than an interval in which the light is confined in the light guide 11 in
(Comparison Among Operation Indicators of First Embodiment)
The operation indicator in
As illustrated in
A diffuse reflection structure 10a that diffusely reflects the light emitted from the operation indicating lamp 8 is formed in a surface facing the operation indicating lamp 8 of the bottom output unit 10. Compared with the operation indicator in
The operation indicating lamp 8 emits the light toward the bottom output unit 10 of the LED holder 7 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The diffuse reflection structure 10a formed in the bottom output unit 10 diffusely reflects the light, which is emitted from the operation indicating lamp 8 to propagate in air, toward the top output unit 2b. The light diffusely reflected toward the top output unit 2b by the diffuse reflection structure 10a is output from the top output unit 2b.
The uniformity and directionality of the light, which is diffusely reflected by the diffuse reflection structure 10a and output from the top output unit 2b, can be improved because the diffuse reflection structure 10a is formed in the bottom output unit 10. Therefore, the visibility is improved when the housing 2 of the relay 1 is observed from obliquely above.
(Configuration of Another Operation Indicator of Second Embodiment)
Similarly to the operation indicator in
The operation indicating lamp 8 emits the light toward the diffuse reflection structure 10a of the LED holder 7 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The diffuse reflection structure 10a diffusely reflects the light, which is emitted from the operation indicating lamp 8 to propagate in air, toward the light guide 11. The light diffusely reflected by the diffuse reflection structure 10a is incident on the light guide 11, totally reflected by the side surface 11a of the light guide 11, guided to the top output unit 2b, and output from the top output unit 2b.
The light, which is diffusely reflected by the diffuse reflection structure 10a, is guided by the light guide 11, and output from the top output unit 2b, because the diffuse reflection structure 10a is formed in the bottom output unit 10. Therefore, the uniformity and directionality of the light output from the top output unit 2b can be improved.
The light diffusely reflected by the diffuse reflection structure 10a is totally reflected by the interface (side surface 11a) with the air layer of the light guide 11. Therefore, the diffusely-reflected light incident on the light guide 11 is uniformed, and the diffusely-reflected light is guided to the top output unit 2b while confined in the square section of the light guide 11. As a result, compared with the configuration in
(Configuration of Still Another Operation Indicator of Second Embodiment)
A diffuse reflection structure 13b that diffusely reflects the light emitted from the operation indicating lamp 8 is formed in a total reflection surface 13a of a total reflection light guide 13. Compared with the operation indicator in
The operation indicating lamp 8 emits the light toward the total reflection light guide 13 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The light emitted from the operation indicating lamp 8 is incident on the total reflection light guide 13, and diffusely reflected by the diffuse reflection structure 13b formed in the total reflection surface 13a. The light diffusely reflected by the diffuse reflection structure 13b is partially guided to the top output unit 2b. The remaining diffusely-reflected light is totally reflected by the side surface of the total reflection light guide 13, and guided to the top output unit 2b. The light guided to the top output unit 2b is output from the top output unit 2b.
The uniformity and directionality of the light, which is diffusely reflected by the diffuse reflection structure 13b of the total reflection light guide 13 and output from the top output unit 2b, can be improved because the diffuse reflection structure 13b is formed in the total reflection light guide 13. Therefore, the visibility is improved when the housing 2 of the relay 1 is observed from obliquely above.
The light diffusely reflected by the diffuse reflection structure 13b is totally reflected by the interface (side surface) with the air layer of the total reflection light guide 13. Therefore, the light diffusely reflected by the diffuse reflection structure 13b is uniformed, and the diffusely-reflected light is guided to the top output unit 2b while confined in the square section of the total reflection light guide 13. As a result, compared with the configuration in
(Comparison Among Operation Indicators of Second Embodiment)
The operation indicator in
The diffuse reflection structure 13b is not formed in the operation indicator in
As illustrated in
Both the diffusion structure 12 of the top output unit 2b and the diffuse reflection structure 10a of the bottom output unit 10 are formed in an operation indicator according to a third embodiment in
The operation indicating lamp 8 emits the light toward the bottom output unit 10 of the LED holder 7 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The diffuse reflection structure 10a formed in the bottom output unit 10 diffusely reflects the light, which is emitted from the operation indicating lamp 8 to propagate in air, toward the top output unit 2b. The diffusion structure 12 of the top output unit 2b diffuses the light diffusely reflected by the diffuse reflection structure 10a of the bottom output unit 10.
The diffuse reflection structure 10a is formed in the bottom output unit 10 while the diffusion structure 12 is formed in the top output unit 2b, so that the uniformity and directionality of the light emitted from the top output unit 2b can further be improved compared with the operation indicators in
(Configuration of Another Operation Indicator of Third Embodiment)
Both the diffusion structure 12 of the top output unit 2b and the diffuse reflection structure 10a of the bottom output unit 10 are formed in another operation indicator in
The operation indicating lamp 8 emits the light toward the diffuse reflection structure 10a of the LED holder 7 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The diffuse reflection structure 10a diffusely reflects the light, which is emitted from the operation indicating lamp 8 to propagate in air, toward the light guide 11. The light diffusely reflected by the diffuse reflection structure 10a is incident on the light guide 11, totally reflected by the side surface 11a of the light guide 11, and guided to the top output unit 2b. The diffusion structure 12 formed in the top output unit 2b diffusely outputs the light guided to the top output unit 2b.
The diffuse reflection structure 10a is formed in the bottom output unit 10 while the diffusion structure 12 is formed in the top output unit 2b, so that the uniformity and directionality of the light emitted from the top output unit 2b can further be improved compared with the operation indicators in
(Configuration of Still Another Operation Indicator of Third Embodiment)
Both the diffusion structure 12 of the top output unit 2b and the diffuse reflection structure 13b of the total reflection light guide 13 are formed in still another operation indicator of the third embodiment in
The operation indicating lamp 8 emits the light toward the total reflection light guide 13 in parallel to the top surface 2a of the case 2 according to the situation of the power supplied to the coil unit 3. The light emitted from the operation indicating lamp 8 is incident on the total reflection light guide 13, and diffusely reflected by the diffuse reflection structure 13b formed in the total reflection surface 13a. The light diffusely reflected by the diffuse reflection structure 13b is partially guided to the top output unit 2b. The remaining diffusely-reflected light is totally reflected by the side surface of the total reflection light guide 13, and guided to the top output unit 2b. The diffusion structure 12 formed in the top output unit 2b diffusely outputs the light guided to the top output unit 2b.
The diffuse reflection structure 13b is formed in the total reflection light guide 13 while the diffusion structure 12 is formed in the top output unit 2b, so that the uniformity and directionality of the light emitted from the top output unit 2b can further be improved compared with the operation indicators in
(Comparison Among Operation Indicators of Third Embodiment)
The operation indicator in
As illustrated in
In the operation indicator of the fourth embodiment in
Therefore, a loss caused by the light leaking from the total reflection light guide 13 can be reduced to enhance the uniformity and directionality of the light output from the top output unit 2b.
(Uniformity and Directionality of Light Output from Operation Indicator in Relays of First to Fourth Embodiments)
(Reflectance of LED Holder 7)
(Diffuse Reflection in Inner Wall 7a of LED Holder 7)
(Reflection by Bottom Output Unit 10 and Leakage Light Caused by Total Reflection Light Guide 13)
However, when an output angle of the light from the operation indicating lamp 8 increases, the light incident on the total reflection light guide 13 from the operation indicating lamp 8 is not totally reflected by total reflection surface 13a but refracted, and the light leaks from the total reflection surface of the total reflection light guide 13 as the leakage light.
(Principle Generating Leakage Light of Total Reflection Light Guide 13)
As to a generation condition of the leakage light L1 refracted by the total reflection surface 13a, the incident angle (critical angle 8c) is less than 39 degrees with respect to the total reflection surface 13a.
The condition that the light guided in polycarbonate constituting the total reflection light guide 13 is refracted by the total reflection surface 13a is considered.
Assuming that θc is a critical angle and that n is a refractive index, θc of 39 degrees is obtained from sin(θc)=(1/n) and the polycarbonate having refractive index n=1.59.
Therefore, the light is refracted by the total reflection surface 13a when being incident on the total reflection surface 13a at the incident angle less than 39 degrees.
At this point, an incident angle θ1 of the light from the operation indicating lamp 8 on the total reflection light guide 13 becomes 9.5 degrees or more.
An incident angle condition that the light is refracted by the total reflection surface 13a is obtained. When the light emitted from the operation indicating lamp 8 is incident on the total reflection light guide 13, a behavior of the light is expressed by a law of refraction.
n1×sin(θ1)=n2×sin(θ2),
refractive index of air: n1=1,
refractive index of polycarbonate: n2=1.59,
because θ2=6 degrees is obtained for incident angle of 39 degrees with respect to the total reflection surface 13a,
1×sin(θ1)=1.59×0.1,
therefore, θ1≈9.5 degrees is obtained.
For example, as illustrated in
(Loss of Light Incident from Operation Indicating Lamp 8 at Total Reflection Surface 13a)
(Diffuse Reflection)
When the light emitted from the operation indicating lamp 8 is diffusely reflected toward the top output unit 2b by the diffuse reflection structure 10a of the bottom output unit 10, the uniformity and directionality of the light output from the top output unit 2b are improved because the light travels in various directions from the diffuse reflection structure 10a.
When the diffuse reflection structure 13b is formed in the total reflection surface 13a of the total reflection light guide 13 to diffusely reflect the light from the operation indicating lamp 8 toward the top output unit 2b, the uniformity and directionality of the light output from the top output unit 2b are improved because the light travels in various directions from the diffuse reflection structure 13b. However, as described above with reference to
(Definitions of Diffusion Structure 12 and Diffuse Reflection Structures 10a and 13b)
The diffusion structure 12 is a rough surface (texturing surface) in which fine irregularities are randomly formed on the surface of the top output unit 2b of the case 2. In the rough surface, desirably surface roughness is less than or equal to 67 μm, and haze value is greater than or equal to 44.7%.
As can be seen from
In the diffuse reflection structures 10a and 13b, similarly to the diffusion structure 12, the surface roughness ranges from 4 μm to 30 μm, and the haze value ranges from 48% to 87%.
(Measure Against Soot Fouling)
The present invention is not limited to the above embodiments, and various changes can be made without departing from the scope of the present invention. It is noted that embodiments obtained by a combination of different embodiments is also included in the scope of the present invention.
One or more embodiments of the present invention may be applied to the relay. One or more embodiments of the present invention may be applied to the relay having the function of displaying the light emitting operation.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
Number | Date | Country | Kind |
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2014-122356 | Jun 2014 | JP | national |