JPH0230751Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power switch for a lens meter.

Conventional lens meters use AC100V supplied from a household outlet for illuminating the measurement target.
Power was supplied using a normal plug cord. However, the lensmeter sometimes needs to be taken to the store to measure the refractive properties of the eyeglass lenses used by the customer, and when processing fabric lenses, it is necessary to use the lensmeter at the optical axis marking point of the lens to be processed. It is necessary to use it in the processing shop to determine the cylinder axis and cylinder axis, and it is necessary to move the lens meter each time. When moving the lens meter, it is necessary to insert the power supply plug into the outlet at the place of use each time, and the power cord comes into contact with other instruments and parts when moving the lens meter, causing them to fall and be damaged. Ta.

In addition, lens meters are not used all the time, but are used to illuminate the measurement target by turning on the power switch only when necessary. , I often leave the power on all day long. In this case, the deterioration of the lighting bulb and the power consumption cannot be ignored.

Furthermore, as another example of a lens meter, one is known in which a power switch is provided in the lens holder and the power switch is turned on only when the lens to be tested is held by the lens holder. However, the lens meter sometimes takes measurements without using the lens holder, and in such cases the lens meter has the disadvantage that the power switch cannot be turned on.

The present inventor devised a cordless battery-powered lens meter to provide a lens meter without a power cord. By the way, the battery is
The disadvantage is that the CaPacity is small, and the power is quickly consumed unless the power is turned on only when in use and turned off when not in use.
It is clear that the lens meter needs to be turned on and off more frequently than with conventional lens meters. In order to solve the problems of cordless battery-operated lens meters, the present invention detects when a person is using the lens meter, and in response to this, the power switch is automatically turned on, allowing the person taking the meter to use the lens meter. The purpose of this design was to provide a lens meter that automatically turned off the power when checking the usage status of the camera.

The structural feature of the present invention is that it consists of a light emitting part and a light receiving part powered by a solar cell, and the luminous flux emitted from the light emitting element provided in the light emitting part is reflected by the examiner's eye during the examination. The measurement light source of the lens meter is configured to be ON only while the light is being incident on the light receiving element provided in the light receiving section. Therefore, according to the present invention, the light source of the lensmeter is automatically turned on only when the examiner approaches the eyepiece of the lensmeter, and automatically turns on when the examiner's eye moves away from the eyepiece of the lensmeter. The lens meter's measurement light source is turned off at the same time, which prevents unnecessary consumption of the measurement power battery. Furthermore, as the power source of the light source switch circuit for measurement, a solar cell is used which can obtain power to operate depending on the brightness of the room in which the lens meter is installed, which is economical. Furthermore, according to the present invention, the power switch for turning on and off the measurement light source of the lens meter can be turned on simply by the examiner's eye approaching the eyepiece.
Therefore, measurements can be made in the same way whether the lens holder of the lens to be tested is used or not.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the lens meter 1 includes a measurement light source 2, a diffusion glass 4, an index 6, a measurement lens 8, a protective glass 10, a filter 12, an objective lens 14,
A focusing plate 16 and an eyepiece lens 18 are arranged on the same optical axis and housed in a housing 20. The lens 30 to be tested is inserted between the holding glass and the filter 12 and measured. The light beam from the light source 2 is diffused by the diffusion glass 4 and illuminates the index 6. The luminous flux from the illuminated index 6 is converted into a parallel luminous flux by the measuring lens 8, passes through the protective glass 10, further passes through the test lens 30 and the filter 12, and is directed onto the focus plate 16 by the objective lens 14. Form an image. The mark on the focus plate 16 and the index image are magnified and observed by the examiner's eye 19 through the eyepiece 18. In the measurement, the measurement lens 8 is moved and adjusted according to the refractive power of the lens 30 to be tested so that the pattern of the optotype 6 is imaged on the focus plate 16. Test lens 12 determined by the amount of movement of measurement lens 8 at this time.
is proportional to the refractive power of If the lens 30 to be tested is for astigmatism, that is, has different refractive powers in two diametrical directions that are at right angles to each other, the refractive power is measured in each diametrical direction, and the results are calculated using a predetermined method. As shown in Figure 2, the light source switch section is
It is divided into a light projecting section 40 and a light receiving section 42, which are arranged at symmetrical positions around the lens barrel 44 of the eyepiece 18, for example, vertically or horizontally. The light projecting section 40 is composed of a light emitting element 46 and a projection lens 48.
The operating power source for the light emitting element 46 is a solar cell 50 arranged on the lower upper surface of the housing 20, and the light projecting section 40 continues projecting light when the lens meter is placed in a place where the brightness is above a predetermined level. The light receiving section 42 includes a photoelectric element 52 and a condensing lens 54, and receives the light beam projected from the light projecting section 40 and reflected by the examiner's eye 19. The operating power source of the photoelectric element 52 is the solar cell 50 as well as the light emitting element 46. The photoelectric element 52 is also ready to generate a light reception signal whenever the lens meter is placed in a place where the brightness is above a predetermined level. The light reception signal of the photoelectric element 52 is sent to a power relay 58 that operates a power switch 56 of the lens meter. The power switch 56 opens and closes the connection between the battery 60, which is a power source for the measurement light source of the lensmeter, and the measurement light source (lamp) 2 of the lensmeter. In the above configuration, the photoelectric element 52 is activated and the light source 2 of the lens meter is turned on only while the subject's eye 19 is placed in the observation position, so there is no need to waste battery power due to forgetting to turn off the power switch. Never. Note that the light receiving unit 42 receives light from the light projecting unit 40 and receives the examiner's eye 1.
In order to prevent malfunction due to reception of light other than that reflected by the light emitting element 46, light of a specific frequency is generated from the light emitting element 46, so that the light receiving section 42 is activated only by light of the specific frequency. This is desirable.

As described above, the present invention is particularly effective as a light source switch for a battery-powered lens meter. However, the present invention is not limited thereto, and it goes without saying that conventional lens meters have great effects such as reducing power consumption and preventing deterioration of lighting bulbs.

[Brief explanation of the drawing]

FIG. 1 is an optical diagram of a lens meter, and FIG. 2 is a configuration diagram of an embodiment of the present invention. 1... Lens meter, 2... Light source for measurement, 6
... Index, 8 ... Measurement lens, 14 ... Objective lens, 18 ... Eyepiece lens, 30 ... Test lens,
40... Light projecting section, 42... Light receiving section, 46... Light emitting element, 50... Solar cell, 52... Light receiving element, 6
0...Battery.

Claims (1)

[Claims for Utility Model Registration] (1) The lens meter has a light emitting part and a light receiving part near the eyepiece, and the light emitting part and the light receiving part are powered by a solar cell, and the light emitting part is powered by a solar cell. The measurement light source of the lens meter is turned ON only while the light beam emitted from the provided light emitting element is reflected by the examiner's eye during the examination and enters the light receiving element provided in the light receiving section. A power switch for a lens meter characterized by the following configuration. (2) A power switch for a lens meter according to claim 1, wherein the power source of the measurement light source is a battery-powered lens meter.