Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package
Patent
1998-06-15
2000-08-01
Hardy, David
Active solid-state devices (e.g., transistors, solid-state diode
Housing or package
257 99, 257433, 257 80, 257 81, 257 82, H01L 3300, H01L 310203, H01L 2715
Patent
active
060970847
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a photointerrupter having a light emitting element and a light receiving element oppositely placed through a space to determine a presence or absence of an object passing through the space or the like. More specifically, the invention relates to a photointerrupter having leads provided with a fixing means to prevent against inclination of fitting in soldering, where the photointerrupter is mounted onto a printed substrate and the leads are soldered thereto.
PRIOR ART
A photointerrupter 10 generally has, as shown in FIGS. 5(a)-(b), a light emitting element 1 and a light receiving element 2 that are oppositely placed with a constant gap and fixed by a package 3 of an opaque molded resin or case, enabling light transmission and reception. The photointerrupter 10 has leads 11, 12 for the light emitting element 1 and leads 21, 22 for the light receiving element 2, so that the leads 11, 12, 21, 22 are inserted into through-holes 4a of the printed substrate 4 and soldered by a flow solder to the printed substrate 4.
The photointerrupter 10 of this kind is arranged to have a space 3b oppositely defined by the light emitting element 1 and the light receiving element 2 to allow an object to be detected to pass therethrough. When the light emitted from the light emitting element 1 is blocked, the light receiving element 2 cannot receive the light. When the object to be detected is not in passing, the light receiving element 2 can receive the light emitted by the light emitting element 1. Thus, the object to be detected can be determined of the presence or absence in the opposedly-defined space 3b. However, this opposedly-defined space 3b has an interval of as small as several mm or less (e.g. the interval of the space is approximately 5 mm, where the package has a size of width.times.thickness (depth).times.height of approximately 13.5 mm.times.5 mm.times.10 mm). Accordingly, if positional deviation or inclination is present, the object to be detected cannot pass through the oppositely-defined space 3b or the object to be detected is difficult to be accurately detected. For this reason, the mounting of the photointerrupter 10 onto the printed substrate 4 has to be accurately controlled in height or position by abutting a bottom surface of the package 3 against the printed substrate 4 so that the leads can be insert and soldered, by a flow solder, to through-holes formed in the printed substrate 4.
Where the leads of the photointerrupter are inserted and soldered to through-holes of a printed substrate as stated above, there may be a case that the photointerrupter is inclined or deviated in position due to the movement caused by vibrations during transportation in the solder process. That is, the photointerrupter is extremely small in size and light in weight as stated before. Further, the leads of the photointerrupter is merely inserted into the through-holes of the printed substrate, wherein the diameter of the through-hole is considerably larger (1.3-1.5 times) than the thickness of the lead (diagonal length where rectangular in section). Consequently, if vibration occurs, the photointerrupter is ready to float up. If there occurs floating, inclination or positional deviation during transport, the photointerrupter is soldered at a position as it is, thus being fixed in a state of inclination or deviation in position. In particular, since the photointerrupter is utilized to detect a presence or absence of an object to be detected or a change of state by passing the object to be detected through the gap defined between the light emitting element and the light receiving element. Accordingly, where there is deviation (floating or inclination vertical to the printed substrate) in height or inclination in a horizontal direction even in slight, the object to be detected becomes difficult to move through an opposed portion between the light emitting element and the light receiving element, impairing the function as a sensor. In order to avoid this, devising is made such that so
REFERENCES:
patent: 4933729 (1990-06-01), Soejima et al.
patent: 4977317 (1990-12-01), Iwashima
patent: 5214495 (1993-05-01), Kitanishi
patent: 5391346 (1995-02-01), Nakamura et al.
patent: 5436472 (1995-07-01), Ogawa
Bamba Yasue
Nakai Kenichi
Sano Masashi
Suzuki Shin'ichi
Clark Jhihan B
Hardy David
Rohm & Co., Ltd.
LandOfFree
Photointerruptor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photointerruptor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photointerruptor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-666746