Measuring instrument

A measuring instrument includes a housing, a number of infrared light emitting devices, a number of infrared light receiving devices, at least two light sources, and a controller. The housing includes a first sidewall and a second sidewall substantially parallel to the first sidewall. The infrared light emitting devices are positioned on the first sidewall. The infrared light receiving devices are positioned on the second sidewall and receive infrared lights emitted by the infrared light emitting devices. The controller is electrically coupled to the infrared light receiving devices and the light sources. When one of the infrared light receiving devices does not receive infrared light emitted by a corresponding infrared light emitting device, the controller turns the light sources on.

BACKGROUND

1. Technical Field

The disclosure relates to a measuring instrument.

2. Description of Related Art

Parameters of lenses are measured after the lenses were formed to ensure quality of the lenses. Such measurement is typically carried out in a black box in which a probe is installed. Sometimes, the lens under measurement may become misaligned from the probe and manual realignment is required. However, such realignment is difficult or inconvenient since the black box is too dark to clearly watch the lenses and the probe.

Therefore, it is desirable to provide a measuring instrument, which can overcome the above problems.

DETAILED DESCRIPTION

Embodiments of the present disclosure will now be described in detail below and with reference to the drawing.

Referring to the drawing, a measuring instrument100, according to an exemplary embodiment, is configured for measuring optical parameters of lenses and includes a housing10, a supporting member20, a box30, a scanning probe40, four infrared light emitting devices50, four infrared light receiving devices60, two light sources70, and a controller80.

The housing10is generally cuboid and includes a ceiling11, a floor12, a first sidewall13, and a second sidewall14substantially parallel to the first sidewall13. Both the first sidewall13and the second sidewall14are perpendicularly connected between the ceiling11and the floor12. The housing10also defines an operating window15between the first sidewall13and the second sidewall14.

The supporting member20is generally positioned on the center of the floor12and includes a bottom plate21and a receiving member25for receiving a workpiece90. In this embodiment, the workpiece90is a lens.

The box30is received in the housing10and suspended to the ceiling11. The box30includes a first surface31opposing the supporting member20. The box30defines a through hole310in the first surface31, generally at the center thereof.

The scanning probe40includes a receiving column41and a probe42coaxially extending out from an end of the receiving column41. The scanning probe40is partially received in the box30. In particular, another end of the receiving column41opposite to the probe42extends through the through hole310. The receiving column41can be lifted or lowered with respect to the supporting member20by a driver (not shown) received in the box30, as such, the probe42can be lifted or lowered in the housing10.

In this embodiment, the measuring instrument100further includes a Fresnel lens45. The Fresnel lens45defines a circular opening451generally at the center thereof. The Fresnel lens45is coiled around to one end of the receiving column41adjacent to the probe42through the circular opening451.

The four infrared light emitting devices50are respectively disposed on the first sidewall13and close to the operating window15, and each of the infrared light emitting devices50emits a beam of infrared light. In this embodiment, the distance between two adjacent infrared light emitting devices50is less than 3 centimeters (cm) which is typically less than the thickness of the operator's hand. In particular, the distance between the lowest infrared light emitting device50and the floor11is less than 3 cm and the distance between the highest infrared light emitting device50and the box30is also less than 3 cm.

The four infrared light receiving devices60are respectively disposed on the second sidewall14and also close to the operating window15, and each of the infrared light receiving devices60is aligned with a corresponding infrared light emitting device50and receives the infrared lights emitted by the corresponding infrared light emitting device50.

The two light sources70are positioned on the first surface31of the box30. In this embodiment, both the two light sources70are light emitting diodes (LEDs), which is symmetrical about the receiving column41.

The controller80is received in the box30and is electrically coupled to the infrared light receiving devices60and the two light sources70. The controller80is configured for monitoring whether or not the infrared light receiving devices60receive the beam of infrared light emitted by the corresponding infrared light emitting device50. When at least one of the four infrared light receiving devices60does not receive the beam of infrared light emitted by the corresponding infrared light emitting device50, the controller80can control the two light sources70to illuminate.

In use, when an operator wants to manually adjust the position of the workpiece90through the operating window15, the hand of the operator will block at least one infrared light receiving device60from receiving infrared light emitted by the corresponding infrared light emitting device50. As such, the controller80controls the two light sources70to illuminate. In this embodiment, the Fresnel lens45is positioned between the light sources70and the workpiece90, and gathers light emitted by the light sources70and focuses the light emitted by the light sources70on the workpiece90. Therefore, it can further strengthen of the brightness of the light sources70on the workpiece90, which is convenient to align the scanning probe40with the workpiece90.

It should be noted that the number of the group of the infrared light emitting devices50or the infrared light receiving devices60are not limited to four, but can be any number depending on requirements, for example, the height of the operating window15, as long as the distance between two adjacent infrared light emitting devices50is less than the thickness of a hand of an operator. For example, it also can be only two, if the height of the operating window15is less than three times of the thickness of the hand of the operator, or more than four, if the height of the operating window15is larger than five times of the thickness of the hand of the operator. It should be also noted that the number of the group of the LEDs70is not limited to two, but can be any number depending on requirements. For example, it can be three or more than four, which are disposed around the receiving column41of the scanning probe40and symmetrical about the receiving column41, to further enhance the brightness around the workpiece90.

As compared to typical measuring instruments, the measuring instrument100is capable of providing illumination in a situation that the operator needs to manually adjust the position of the workpiece90. As a result, the measuring instrument100can prevent the scanning probe40from damage by the operator, during the process of the adjustment.

It is understood that the above-described embodiment are intended to illustrate rather than limit the disclosure. Variations may be made to the embodiment without departing from the spirit of the disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.