JPS6120834A - Lensmeter P. D measuring device - Google Patents

Abstract

PURPOSE:To shorten the measurement time and to improve the measurement precision by converting the P.D measured value of spectacles into an electric signal. CONSTITUTION:The spectacles A are pressed against a spectacle frame padding plate 1 and held on a spectacle holding member 2a, and then the optical center of a lens La is on the center of measurement light, i.e. on the center axis of a lens receiver 3 after the alignment of the lens La. The center axis of the lens receiver 3 is known previously, so the holding member 2a moves in parallel to the frame padding plate 1 in a perpendicular plane which contains said center axis and is perpendicular to the surface of the frame padding plate 1, so the distance from a specific position of the holding member 2a, i.e. position contacting the bridge center or the center position between the pads of the spectacles to the perpendicular plane corresponds to the P.D value of the lens La. The holding member 2a is coupled directly with a direct operated type potentiometer 5a, so position information on the holding member 2a is converted into an electric signal. Then, this is read directly on a display device corresponding to the electric signal, and neither mechanical readout operation nor recording operation is required.

Description

DETAILED DESCRIPTION OF THE INVENTION In order to measure various quantities of eyeglass lenses including contact lenses, the present invention measures the distance between the optical centers of two left and right lenses, or the distance between the center of the bridge of eyeglasses and the optical center of the left and right lenses. P of a lens meter that measures distance, so-called P and D values of glasses.
This relates to a D measuring device.

Conventionally, methods for measuring P and D of eyeglasses include the most primitive method of making marks on the left and right lenses after various measurements of the glasses, and measuring the distance between these marks with an attached linear ruler.
A mechanical method is known in which a member for semi-fixing the nose pad of eyeglasses is slid on a linear ruler, and the position of this member is read from the scale of the linear ruler.

These traditional methods generally require considerable time to measure;
Furthermore, since the reading is done mechanically in both cases, the examiner must record the measurement results himself, placing a considerable burden on the examiner.

An object of the present invention is to improve the above-mentioned drawbacks of the conventional example, to enable measurement values of P and D of eyeglasses to be obtained in the form of converted electrical signals, and to display the P and D measurement values of glasses by electrical display means such as a digital display. The object of the present invention is to provide a P and D measuring device for a lens meter that can be outputted to a printer etc., thereby eliminating the need for conventional recording work and increasing the efficiency and labor saving of P and D measurements.
The gist thereof is to include an eyeglass holding member movable in the direction between the lenses of the eyeglasses, means for converting positional information of the eyeglass holding member into an electrical signal, and display means for displaying information provided from the converting means. This is a feature.

The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a first embodiment of the present invention, in which the bridge part or the nose pad part of the glasses A is placed on a glasses analyzer plate 1 for aligning the glasses A to be measured with a predetermined horizontal angle. There are two first ones on the left and right that are held together. Second eyeglass holding members 2a, 2b
are equipped so that they can slide freely. The first eyeglass holding member 2a is used when measuring the left lens La of the eyeglasses A, and the second eyeglass holding member 2b is used when measuring the right lens Lb, and the eyeglasses A are held on either of them. At this time, one lens is placed on the lens holder 3. A box-shaped support body 4 is provided behind the eyeglass analyzer plate 1, and inside thereof are first and second direct-acting potentiometers 5a and 5b that are linked to the movement of the eyeglass holding members 2a and 2b, respectively. is installed. These direct-acting potentiometers 5a, 5b (7) wiring 6a, 6b
In the embodiment, the support member 7 is guided to the outside through the inside of the holding member 7 that holds the support body 4.

FIG. 2 is a block circuit diagram of the electrical system of this embodiment, in which a buffer amplifier 8, an A/D converter 9, and a control circuit 10 are connected following the direct-acting potentiometer 5a or 5b in FIG. An electrical display means 11 such as a 7-segment digital display, a printer 12, etc. are connected to the circuit IO. Note that 13 indicates a measurement switch for sending a signal to the control circuit 10.

Now, to explain the case of measuring the left lens La of eyeglasses A, in FIG. Or both are retained. In this state, for example, if the alignment of the left lens La is completed, the optical center of the lens La will be on the center of the measurement light, that is, on the central axis of the lens receiver 3. Note that when the alignment is completed, the position of the transmitted light shifts depending on whether there is a lens or not for a constant incident light.

The center axis of lens holder 3 is known in advance.

Considering a vertical plane that includes this central axis and is perpendicular to the surface of the eyeglass analyzer plate 1, the eyeglass holding member 2a moves parallel to the eyeglass analyzer plate 1, so that the eyeglass holding member 2a is at a predetermined position, i.e. The distance from the position in contact with the center of the bridge or the center position between the nose pads on the glasses to the vertical plane corresponds to the P and D values of the left lens La. As can be seen from FIG. 1, the eyeglass holding member 2a
is directly connected to the direct-acting potentiometer 5a, so
Here, the position information of the eyeglass holding member 2a is directly converted into an electric signal on a one-to-one basis. As shown in FIG. 2, the direct-acting potentiometer 5a has one end of the resistor connected to a power supply V, and the output from its sliding terminal is amplified by a buffer amplifier 8 and then sent to an A/D converter. is converted into a digital signal. Here, when the measurement switch 13 is turned on, the control circuit 1O takes in the digital signal and displays data corresponding to the digital signal on the display means 11 or the printer 12.
output to the left side P, display and record the measurement results.
Complete the measurement of D value. Similarly, the right side P and D values can be measured using the eyeglass holding member 2b and the direct-acting potentiometer 5b. In addition, as the display means 11, T
V display.

LEDs, liquid crystals, etc. are used, and for example, r31mmJ is displayed.

FIG. 3 is a perspective view of only the main parts of a second embodiment of the present invention, in which an encoder is used in place of the direct-acting potentiometer shown in FIG. 1, and its electrical block circuit diagram is shown. It is shown in Figure 4. In addition, in these FIGS. 3 and 4, the same reference numerals as in FIGS. 1 and 2 represent the same or equivalent members.

In FIG. 3, the encoder 14 is installed in the support 4, and the brush board 16 with the sliding brush 15 attached thereto is
The wiring member 17 is connected to the glasses holding member 2a or 2b so as to be interlocked, and the wiring member 17 is drawn out from the sliding brush 15. The operation of the eyeglass holding member 2a or 2b is the same as in the previous example, and the measured value is obtained by detecting the position of the eyeglass holding member 2a or 2b.

In FIG. 4, the encoder 14 is grounded and the sliding brush 15 is pulled up to the power supply V via the pull-up resistor 18, so the potential of the sliding brush 15 is at ground level when connected to the electrode of the encoder 14. In other cases, the voltage is at the same level as the voltage of the power supply V. This level signal is input to the control circuit IO through the data line 19, and if the electrode pattern 14a of the encoder 14 is formed, for example, like the hatched area in FIG. Absolute position can be detected. Since the detection signal is a level signal, that is, a digital signal as described above, an A/D converter is not required in this embodiment, and when the measurement switch 13 is turned on as in the previous embodiment, the signal is transmitted to the display means 11 and the printer 12. Measurement results can be output.

6 and 7 are a configuration diagram and an electric block circuit diagram showing a third embodiment of the present invention, in which a light emitting element 20 such as a light emitting diode is fixed together with a mounting 21 on an eyeglass holding member 2a or 2b. However, a one-dimensional position detection element 23 is installed on the support body 4 via a substrate 22.

The feature of this embodiment is that the position of the eyeglass holding member 2a or 2b is photoelectrically detected. For example, the light emitting element 20 The position of the center of gravity of the light spot that is being irradiated can be obtained.

Therefore, the output of the differential amplifier circuit 24 in FIG. 7, which calculates the difference between the output signals of the -dimensional position detection element 23, corresponds to the position of the light emitting element 20, that is, the eyeglass holding member 2a or 2b, in a one-to-l ratio. , the output of this differential amplifier circuit 24 is A/
By converting it into a digital signal using the D converter 9 and inputting it to the control circuit 10, it is possible to output the P and D measurement results to the display means 11 and printer 12 as in the previous two embodiments.

In FIG. 7, reference numeral 25 indicates a resistor for determining the current flowing to the light emitting element, and reference numeral 26 indicates a bias voltage that is constantly applied to the one-dimensional position detection element 23.

In each of these first, second, and third embodiments, the measurement is started by turning on the measurement switch 13.
Depending on the type of control circuit 1O, it is also possible to perform rotation setting and display continuously. Further, as in the third embodiment, when a photoelectric conversion means is used, in addition to the one-dimensional PSD, the one-dimensional position detection element 23 may be a -dimensional CO
It is also possible to use a D linear image sensor or a simple photodiode array or the like. Furthermore, the glasses holding member 2a,
As the means for converting the position information 2b into an electrical signal, it is possible to use a method other than the one in the embodiment, and it is also possible to display the analog quantity on a meter or the like without converting it to a digital quantity.

As explained above, P and D of the lens meter according to the present invention
Since the measurement device obtains the P and D measurement values of the glasses in the form of converted electrical signals, the measurement results can be input to a digital display, printer, etc. for display or recording, and as a result, conventional Since the mechanical reading and recording work that was previously required by the examiner is no longer required, the burden on the examiner can be significantly reduced, the time required for measurement can be shortened, and measurement accuracy can also be increased. .

[Brief explanation of the drawing]

The drawings show an embodiment of the P and D measuring device of a lens meter according to the present invention, and FIG. 1 is a partially cutaway perspective view of the first embodiment, and FIG. 2 is an electric block circuit diagram thereof. , Fig. 3 is a perspective view of the main part of the second embodiment, Fig. 4 is an electric block circuit diagram thereof, Fig. 5 is an explanatory diagram of the electrode pattern of the encoder, and Fig. 6 is a main part of the third embodiment. The perspective view and FIG. 7 are its electrical block circuit diagrams. Reference numeral 1 indicates an eyeglass frame light plate, 2a and 2b indicate eyeglass holding members, and 3
is a lens receiver, 4 is a support, 5a, 5b are direct-acting potentiometers, 8 is a buffer amplifier, 9 is an A/D converter, 10 is a control circuit, 11 is a display means, 12 is a printer, 13 is a measurement switch, 14 1 is an encoder, 15 is a sliding brush, 20 is a light emitting element, 23 is a one-dimensional position detection element, and 24 is a differential amplifier. Patent applicant Canon Co., Ltd. Drawings 1.1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. An eyeglass holding member movable in the direction between the lenses of the eyeglasses;
A P and D measuring device for a lens meter, comprising means for converting positional information of the eyeglass holding member into an electrical signal, and display means for displaying information provided from the converting means. 2. The P and D measuring device for a lens meter according to claim 1, wherein the means for converting the position information into an electric signal is a photoelectric conversion means. 3. The P and D measuring device for a lens meter according to claim 1, wherein the display means is a digital display.