1. An optical encoder comprising;
a scale provided with a periodic pattern in which an optical portion reflecting or transmitting light is periodically formed with a first period in a first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein, when a direction orthogonal to the first direction in the periodic pattern is defined as a second direction, the optical portion periodically has a pattern, which is formed pattern portions mutually adjacent in the second direction and mutually shifted in the first direction, in the second direction with a second period of t, and
wherein a width w of the light source in the second direction satisfies the following condition:
w=(a+b)b\xb7nt
where n represents a natural number, and a:b represents a ratio of a distance from the light source to the periodic pattern and a distance from the periodic pattern to the light receiver.
2. An optical encoder according to claim 1, wherein a width v of the light receiver in the second direction satisfies the following condition:
v=(a+b)a\xb7mt
where m represents a natural number.
3. An optical apparatus comprising:
an optical encoder according to claim 1; and
a movable member whose position is detected by the optical encoder.
4. An optical encoder comprising;
a scale provided with a periodic pattern in which an optical portion reflecting or transmitting light is periodically formed with a first period in a first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein, when a direction orthogonal to the first direction in the periodic pattern is defined as a second direction, a proportion of the optical portion and a non-optical portion of the periodic pattern in the second direction is changed in the first direction, and the periodic pattern periodically includes a pattern, which is formed by the optical portion and the non-optical portion, in the second direction with a second period of t, and
wherein a width w of the light source in the second direction satisfies the following condition:
w=(a+b)b\xb7nt
where n represents a natural number, and a:b represents a ratio of a distance from the light source to the periodic pattern and a distance from the periodic pattern to the light receiver.
5. An optical encoder according to claim 3, wherein a width v of the light receiver in the second direction satisfies the following condition:
v=(a+b)a\xb7mt
where m represents a natural number.
6. An optical apparatus comprising;
an optical encoder according to claim 4; and
a movable member whose position is detected by the optical encoder.
7. An optical encoder comprising:
a scale provided with a periodic pattern in which an optical portion reflecting or transmitting light is periodically formed with a first period in a first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein, when a direction orthogonal to the first direction in the periodic pattern is defined as a second direction, a proportion of the optical portion and a non-optical portion of the periodic pattern in the first direction is changed in the second direction, and the periodic pattern periodically includes a pattern, which is formed by the optical portion and the non-optical portion, in the second direction with a second period of t, and
wherein a width w of the light source in the second direction satisfies the following condition:
w=(a+b)b\xb7nt
where n represents a natural number, and a:b represents a ratio of a distance from, the light source to the periodic pattern and a distance from the periodic pattern to the light receiver.
8. An optical encoder according to claim 7, wherein a width v of the light receiver in the second direction satisfies the following condition:
v=(a+b)a\xb7mt
where m represents a natural number.
9. An optical apparatus comprising:
an optical encoder according to claim 7; and
a movable member whose position is detected by the optical encoder.
10. An optical encoder comprising:
a scale provided with a periodic pattern in which an optical portion reflecting or transmitting light is periodically formed with a first period in a first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein, when a direction orthogonal to the first direction in the periodic pattern is defined as a second direction, the periodic pattern periodically includes a pattern, which is formed by the optical portion and a non-optical portion, in the second direction with a second period of t, and
wherein a width w of the light source in the second direction satisfies the following condition:
w=(a+b)b\xb7nt
where n represents a natural number, and a:b represents a ratio of a distance from the light source to the periodic pattern and a distance from the periodic pattern to the light receiver.
11. An optical, encoder according to claim 10, wherein a width v of the light receiver in the second direction satisfies the following condition:
w=(a+b)b\xb7nt
where m represents a natural number.
12. An optical apparatus comprising:
an optical encoder according to claim 10; and
a movable member whose position is detected, by the optical encoder.
13. An optical encoder comprising:
a scale provided with a multiple periodic pattern including a plurality of patterns in which (a) in each pattern an optical portions reflecting or transmitting light is periodically formed with a first period in a first direction, (b) the first periods in the respective patterns are mutually different, and (c) the patterns are multiply formed in a second direction orthogonal to the first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period of a specific pattern among the patterns of the multiple periodic pattern,
wherein the scale and the light receiver and relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein the multiple periodic pattern periodically includes a pattern, which is formed by the optical portion and a non-optical portion, in the second direction with a second period of t, and
wherein a width w of the light source in the second direction satisfies the following condition:
w=(a+b)b\xb7nt
where n represents a natural number, and alb represents a ratio of a distance from the light source to the multiple periodic pattern and a distance from the multiple periodic pattern to the light receiver.
14. An optical encoder according to claim 13, wherein a width v of the light receiver in the second direction satisfies the following condition:
v=(a+b)a\xb7mt
where m represents a natural number.
15. An optical apparatus comprising:
an optical encoder according to claim 13; and
a movable member whose position is detected by the optical encoder.
16. An optical encoder comprising:
a scale provided with a multiple periodic pattern including a plurality of patterns in which (a) in each pattern an optical portions reflecting or transmitting light is periodically formed with a first period in a first direction, (b) the first periods in the respective patterns are mutually different, and (c) the patterns are multiply formed in a second direction orthogonal to the first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period of a specific pattern among the patterns of the multiple periodic pattern,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein the multiple periodic pattern periodically includes a pattern, which is formed by the optical portion and a non-optical portion, in the second direction with a second period of t, and
wherein when w represents a width of the light source in the second direction and a:b represents a ratio of a distance from the light source to the periodic pattern and a distance from the periodic pattern to the light receiver, the scale is configured so that the second period t takes on a value based on the width w and the ratio a:b.
17. An optical encoder according to claim 16, wherein the light receiver is configured so that a width v of the light receiver in the second direction takes on a value based on the second period t and the ratio a:b.
18. An optical apparatus comprising:
an optical encoder; and
a movable member whose position is detected by the optical encoder,
wherein the optical encoder comprises:
a scale provided with a periodic pattern in which an optical portion reflecting or transmitting light is periodically formed with a first period in a first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein, when a direction orthogonal to the first direction in the periodic pattern is defined as a second direction, a proportion of the optical portion and a non-optical portion of the periodic pattern in the second direction is changed in the first direction, and the periodic pattern periodically includes a pattern, which is formed by the optical portion and the non-optical portion, in the second direction with a second period of t, and
wherein when w represents a width of the light source in the second direction and a:b represents a ratio of a distance from the light source to the periodic pattern and a distance from the periodic pattern to the light receiver, the scale is configured so that the second period t takes on a value based on the width w and the ratio a:b.
19. An optical encoder comprising:
a scale provided with a periodic pattern in which an optical portion reflecting or transmitting light is periodically formed with a first period in a first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having change period corresponding to the first period,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein, when a direction orthogonal to the first direction in the periodic pattern is defined as a second direction, a proportion of the optical portion and a non-optical portion of the periodic pattern in first direction is changed in the second direction, and the periodic pattern periodically includes a pattern, which is formed by the optical portion and the non-optical portion, in the second direction with a second of t, and
wherein when w represents a width of the light source in the second direction and a:b represents a ratio of a distance from the light source to the periodic pattern and a distance from the periodic pattern to the light receiver, the scale is configured so that the second period t takes on a value based on the width w and the ratio a:b.
20. An optical encoder according to claim 19, wherein the light receiver is configured so that a width v of the light receiver in the second direction takes on a value based on the second period t and the ratio a:b.
21. An optical apparatus comprising:
an optical encoder; and
a movable member whose position is detected by the optical encoder,
wherein the optical encoder comprises:
a scale provided with a periodic pattern in which an optical portion reflecting or transmitting light is periodically formed with a first period in a first direction; and
a light receiver configured to photoelectrically convert a detection light emitted from a light source and then passing via the scale into an output signal having a change period corresponding to the first period,
wherein the scale and the light receiver are relatively movable in the first direction,
wherein the optical portion is configured to direct the light from the light source to the light receiver,
wherein, when a direction orthogonal to the first direction in the periodic pattern is defined as a second direction, a proportion of the optical portion and a non-optical portion of the periodic pattern in the first direction is changed in the second direction, and the periodic pattern periodically includes a pattern, which is formed by the optical portion and the non-optical portion, in the second direction with a second period of t, and
wherein when w represents a width of the light source in the second direction and a:b represents a ratio of a distance from the light source to the periodic pattern and a distance from the periodic pattern to the light receiver, the scale is configured so that the second period t takes on a value based on the width w and the ratio a:b.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-5. (canceled)
6. An actuator with an elongate housing, a piston arranged for linear travel through the housing and a coupling for transmitting movement of the piston into corresponding mechanical output of the actuator, the actuator having an external connector at an end of the housing remote from the coupling, the connector being coupled to the piston so that linear movement of the piston causes rotation of the connector so as to indicate a position of the piston within the housing.
7. The actuator of claim 6, wherein the coupling is a piston rod, which projects externally of the housing.
8. The actuator as claimed in claim 6, wherein the connector includes a rotating hub with a radial slot to engage a shaft of an accessory unit.
9. The actuator as claimed in claim 8, wherein the slot is in the order of substantially 4 mm in width and substantially 6 mm in depth, to fit with standardised rotary accessories.
10. The actuator as claimed in claim 9, wherein the hub has a height dimension in the order of substantially 20 mm.
11. The actuator as claimed in claim 8, further including a bracket connected relative to the housing, the bracket having a mounting plate to which the accessory is secured and an opening through which the shaft of the unit passes to engage with the connector.
12. The actuator as claimed in claim 11, wherein the mounting plate sits over the connector and is spaced from the end of a housing by supporting legs which are mounted to the housing such that the opening aligns with the connector.
13. The actuator as claimed in claim 12, wherein the mounting plate includes preformed through holes, for receipt of fasteners which are used to attach the accessory unit to the bracket.
14. The actuator as claimed in claim 6, wherein the connector is coupled to a twisted bar which extends axially though the housing, the bar passing through a guide slot in the piston, whereby axial movement of the piston causes rotation of the bar, to thereby rotate the connector.
15. The actuator as claimed in claim 6, wherein the connector is coupled to a rod which extends axially through the housing, the rod passing through a guide slot in the piston which couples with flutes formed helically along the rod, whereby axial movement of the piston causes rotation of the rod, to thereby rotate the connector.
16. The actuator as claimed in claim 6, wherein an elongate stabilizing bar is fitted internally of the actuator to prevent the piston rotating as the piston travels through the housing.
17. The actuator as claimed in claim 1, in combination with an accessory unit in the form of a rotary switchbox, positioner or indicator, the unit having a shaft engaged with the connector of the actuator to provide input to the unit corresponding to the rotary position of the connector, which thereby indicates the linear position of the piston.
18. An actuator with an elongate housing, a diaphragm arranged for linear travel through the housing and a coupling for transmitting movement of the diaphragm into corresponding mechanical output of the actuator, the actuator having an external connector at an end of the housing remote from the coupling, the connector being coupled to the diaphragm so that linear movement of the diaphragm causes rotation of the connector so as to indicate a position of the diaphragm within the housing.