1. A yarn sensor for optically scanning a yarn traveling in its lengthwise direction through a measurement gap, comprising:
a light source for projecting a beam of light across the measurement gap,
a first receiver for directly transmitted light,
a second receiver for light reflected from the yarn,
a third receiver for light reflected from the yarn, and
elements for transmitting the light between the light source, measurement gap and receivers,
the light transmitting elements comprising:
a first light-transmitting element disposed between the light source and the measurement gap and including a diaphragm and a lens, downstream of the light source in the direction of light projection, and arranged such that the diaphragm is projected at least approximately into infinity, and
second and third light-transmitting elements respectively disposed between the measurement gap and the second and third reflected light receivers,
each of the second and third light-transmitting elements comprising a lens disposed upstream in the projected direction of the light reflected from the yarn such that, in the absence of the yarn, projected images on an opposing surface of the measurement gap are detectable by the second and third receivers essentially outside both opposite sides of a projected image of the light source across the measurement gap.
2. The yarn sensor of claim 1, wherein the light source is a light-emitting diode having an emission characteristic of a Lambert emitter.
3. The yarn sensor of claim 2, characterized in that the light-emitting diode is a white light LED.
4. The yarn sensor of claim 1, wherein a diffusor is disposed between the light source and the diaphragm upstream of the diaphragm.
5. The yarn sensor of claim 4, characterized in that the diffusor is a film for generating divergent beams of light from beam of light of the light source.
6. The yarn sensor of claim 1, wherein the lens of the first light transmitting element comprises a light entrance side arranged to homogeneously distribute the luminous intensity the light beam from the light source in the direction of the optical axis of the lens and comprises an exit side arranged to project the light beam arriving from the entrance side essentially parallel to the optical axis of the lens.
7. The yarn sensor of claim 1, wherein the light transmitting elements are separated from the measurement gap by windows.
8. The yarn sensor of claim 1, wherein a second diaphragm with a rectangular aperture is disposed between the lens of the first light transmitting element and the yarn.
9. The yarn sensor of claim 1, wherein each of the second and third light transmitting elements comprises a diaphragm disposed between the yarn and the lens in path of the light reflected by the yarn.
10. The yarn sensor of claim 9, wherein the diaphragm of each of the second and third light transmitting elements is embodied by a glass plate.
11. The yarn sensor of claim 1, wherein a signal processing device is arranged to detect and evaluate signal interferences.
12. A yarn sensor for optically scanning a yarn traveling in its lengthwise direction through a measurement gap, comprising:
a light source for projecting a beam of light across the measurement gap, wherein the light source is a light-emitting diode having an emission characteristic of a Lambert emitter,
a first receiver for directly transmitted light,
a second receiver for light reflected from the yarn,
a third receiver for light reflected from the yarn, and
elements for transmitting the light between the light source, measurement gap and receivers,
the light transmitting elements comprising:
a first light-transmitting element disposed between the light source and the measurement gap and including a diaphragm and a lens, downstream of the light source in the direction of light projection, and arranged such that the diaphragm is projected at least approximately into infinity, and
second and third light-transmitting elements respectively disposed between the measurement gap and the second and third reflected light receivers,
each of the second and third light-transmitting elements comprising a lens disposed upstream in the projected direction of the light reflected from the yarn such that, in the absence of the yarn, projected images on an opposing surface of the measurement gap are detectable by the second and third receivers essentially outside both opposite sides of a projected image of the light source across the measurement gap.
13. The yarn sensor of claim 12, characterized in that the light-emitting diode is a white light LED.
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. A method comprising:
receiving, by a document management system executing on one or more processors of a server device, a file update notification message from a first client device to notify the document management system that a file was modified by the first client device, wherein the file update notification message includes an indication of the modified file on the first client device without including the modified file;
receiving, by the document management system, a file editing request from a second client device to request the file from the document management system;
responsive to receiving the file editing request from the second client device, sending, by the document management system, a file upload request to the first client device to request the modified file from the first client device;
receiving, by the document management system, the modified file from the first client device; and
sending, by the document management system, the modified file to the second client device.
2. The method of claim 1, wherein sending the file upload request to the first client device is responsive to determining, by the document management system and based on the received file update notification message, that the first client device stores a most recently modified version of the file.
3. The method of claim 1, wherein the file update notification message further includes at least one of an indication of a time when the first client device modified the file, a version number of the file, or an identifier of a user of the first client device.
4. The method of claim 1, further comprising:
receiving, by the document management system, a file editing request from the first client device to request the file from the document management system; and
associating, by the document management system, a file editing lock with the indication of the file and an indication of the first client device.
5. The method of claim 4, further comprising:
responsive to receiving the file editing request from the second client device, sending, by the document management system, a file editing unlock request to the first client device;
receiving, by the document management system, an unlock confirmation message from the first client device to indicate that the first client device relinquishes the file editing lock associated with the file; and
responsive to receiving the unlock confirmation message, disassociating the file editing lock from the indication of the file and the indication of the first client device.
6. The method of claim 1, further comprising:
associating, by the document management system, a file editing lock with the indication of the file and an indication of the second client device;
receiving, by the document management system, a file editing request from a third client device;
responsive to receiving the file editing request from the third client device, sending, by the document management system, a file editing unlock request to the second client device;
receiving, by the document management system, an unlock rejection message from the second client device to indicate that the second client device does not relinquish the editing lock associated with the file; and
responsive to receiving the unlock rejection message, sending, by the document management system, a file editing rejection message to the third client device.
7. A method comprising:
modifying a file by a client device;
storing the modified file at a computer-readable storage media of the client device;
sending, by the client device, a file update notification message to a document management system executing on one or more processors of a server device to notify the document management system that the client device modified the file, wherein the file update notification message includes an indication of the modified file stored at the computer-readable storage media of the client device without including the modified file.
8. The method of claim 7, wherein sending the file update notification message to the document management system is responsive to determining, by a file system monitor executing on one or more processors of the client device, that the client device modified the file.
9. The method of claim 7, further comprising:
receiving, by the client device, a file upload request from the document management system to request the modified file from the client device; and
sending, by the client device, the modified file to the document management system.
10. The method of claim 7, wherein the file update notification message further includes at least one of an indication of a time when the client device modified the file, a version number of the file, or an identifier of a user of the client device.
11. The method of claim 7, further comprising:
receiving, by the client device, a file editing unlock request message from the document management system, wherein the file editing unlock request message includes an indication of the modified file; and
sending, by the client device, an unlock rejection message to the document management system to indicate that the client device does not relinquish an editing lock associated with the file.
12. The method of claim 7, further comprising:
receiving, by the client device, a file editing unlock request message from the document management system, wherein the file editing unlock request message includes an indication of the modified file; and
sending, by the client device, an unlock confirmation message to the document management system to indicate that the client device relinquishes an editing lock associated with the file.