JP3066148B2 - Automatic lens meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens meter for measuring an optical characteristic of a test lens.

[0002]

2. Description of the Related Art A lens meter is provided with an alignment mechanism comprising a reticle and a target for aligning a measurement optical path with a lens to be measured. Further, there is known a marking mechanism for marking a lens to be inspected in order to process the optical center and the axis of the lens to be located at predetermined positions. For this marking point, it is necessary to move the target to a predetermined position on the reticle and to rotate it by the required marking point angle (the angle between the marking point direction and the axial direction of the cylinder shaft). Conventionally, the operator memorizes the mark angle and moves the target based on that memorization.

[0003]

In the alignment operation for the above-mentioned mark, the target is not deviated from the center of the reticle or the axis of the target coincides with the stored mark angle. It must be observed whether the target and the axis of the test lens are alternately
Operation is complicated. In addition, a burden is imposed on the examiner for storing the axis angle. SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens meter capable of relieving an examiner from the troublesome and inefficient work as described above and easily forming a mark.

[0004]

The present invention has the following features to achieve the above object. (1) In an automatic lens meter that automatically measures optical characteristics such as spherical power and astigmatic power of a test lens inserted into a measurement optical system , the optical center of the test lens with respect to the optical axis of the measurement optical system Of the measurement light
Detecting means for detecting based on measurement by a scientific system, a display for displaying a reticle for alignment, and a marking point
Input means for inputting a mark angle indicating the direction of the astigmatic axis with respect to the direction of the mark, and indicating the input mark angle.
Mark and displays superimposed on the reticle, characterized in that and a display display control means for displaying the alignment target indicating the direction of the optical center and the astigmatic axis on the display based on said detection means.

(2) The automatic lens meter of (1) further includes monitoring means for monitoring whether or not the measured direction of the astigmatic axis coincides with the mark angle, and notification for notifying the operator of the monitoring result. and having a means.

[0006]

[0007]

[0008]

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a lens meter according to an embodiment of the present invention. 1 is a graphic display, and 2 is a reticle composed of concentric circles and meridians about the optical axis of the measuring optical system. The reticle 2 is drawn on a transparent film and attached on the screen of the display 1. The reticle may be a display such as graphic drawing instead of attaching a film. The screen of the display 1 displays A indicating the mark angle input by the AXIS switch described later.
The XI mark 3, the target 4, the measurement result, and the like are displayed. The target 4 is a cross-shaped mark. When the test lens has an AXIS axis, the axis is displayed as the long axis. 5a is a print switch for printing the measurement result, 5b
Is a left / right selection switch, and 6 is a switch for reading a measured value. Reference numeral 7 denotes a lens holder, 8 denotes a nosepiece, and a lens to be measured is placed on the nosepiece 8,
The lens holder 7 is lowered to hold the test lens. 9 is a marking device. Reference numeral 10 denotes an AXIS switch for inputting a dot point angle, and reference numeral 10 'denotes an auxiliary switch for assisting the AXIS switch 10 in setting a numerical value.

Next, the measuring optical system of the apparatus will be described with reference to the optical system layout diagram of FIG. Reference numeral 11 denotes a light emitting diode such as an LED, and four light emitting diodes are arranged near the focal point of the condenser lens 12 in a direction perpendicular to the optical axis. When the lens to be inspected 15 is set with respect to the nosepiece 8, the LED driver operates according to an instruction from the computer, and the four LEDs a,
b, c, and d are sequentially turned on. Reference numeral 13 denotes a measurement target plate having orthogonal slits.
2 and is fixed or movable near the focal point of the collimating lens 14. The nosepiece 8 is disposed near the focal point of the collimating lens 14 and the imaging lens 16. Reference numeral 17 denotes a half prism, and reference numeral 18 denotes an image sensor provided orthogonal to the optical axis.
Light from the LED is collimated by the condenser lens 12.
Focusing lens 14, test lens 15, imaging lens 16
Are formed on two image sensors 18 orthogonal to each other.

Next, it is a block diagram showing a control system of the present apparatus. The signals from the two image sensors 18 are input to a comparator 22 and a peak hold circuit 23 via a CCD drive circuit 21. The peak voltage detected and input to the peak hold circuit 23 is converted into a digital signal by the A / D converter 24 and then input to the micro computer 25. The digital signal of the peak voltage output from the peak hold circuit 23 is converted into a voltage signal of 1/2 the peak voltage by a D / A converter 26 via a computer 25. It is input to the comparator 22.
This signal is compared with the signal directly input to the comparator 22 to generate a strobe signal. The signal of the counter 27 enters the latch 28 in response to the strobe signal, and the position of the light-dark edge is read from the waveform at that time, and the microcomputer 25 obtains the coordinate position based on the signal.

Next, a measured value is calculated from the coordinate position. The target 13 is individually illuminated by four LEDs, but when there is no lens to be inspected and when the lens of 0D is
LED8, LEDa, b, c, d
All the target images formed on the image sensor 18 by each overlap. When the test lens 15 has only spherical refracting power, the position of the target image formed on the image sensor 18 moves on the image sensor 18 by an amount corresponding to the spherical refraction power. When the test lens 15 has only the cylindrical power, the light incident on the cylindrical lens has a refractive power in a direction (or the same direction) orthogonal to the main meridian. The columnar refractive power can be calculated from the amount of movement of the target image. When the test lens 15 has both a spherical refractive power and a cylindrical refractive power, the target image moves on the image sensor 18 by an amount corresponding to each refractive power value and forms an image. Now, LEDa, b, c, data at the time of lighting the d - center of the target image, respectively _{A (x a, y a)} , B
_{(X b, y b),} C (x c, y c), and _{D (x d, y d)} ,

(Equation 1)

(Equation 2)

(Equation 3)

(Equation 4) After all,

(Equation 5)

(Equation 6)

(Equation 7)

(Equation 8) Becomes The coordinate position is detected by the microcomputer 25, the spherical refraction, the columnar refraction, and the axis angle are calculated based on the above-mentioned calculation formula, and the values are displayed by the character display circuit 29, and the values are displayed. The target 4 is displayed on the display 1 at the optical center position of the lens to be inspected by the graphic display circuit 30 based on the above. The graphic display circuit 30 displays a meridian passing through the center of the reticle 2 at a position corresponding to the mark angle input by the AXIS switch 10 and the auxiliary switch 10 '.

A description will now be given of the marking points of the apparatus having the above configuration. First, the reticle 2 is displayed on the display when power is input (A in FIG. 4). Next, AX
The IS switch 10 is pressed to enter the AXIS preset mode, and the axis angle is input by the AXIS switch 10 and the auxiliary switch 10 '. The switch 10 advances the numerical value in the plus direction, and the auxiliary switch 10 'decreases the numerical value.
When the setting is started, the AXIS mark 3 is displayed on the display 1 (B in FIG. 4). Next, the test lens is
On the surface 8. The apparatus continuously measures the refractive power of the lens to be measured, and displays a target 4 on the reticle 2 corresponding to the amount of deviation (the amount of prism) between the optical center of the lens to be measured and the measurement optical axis ( FIG. 4C). The lens is moved so that the target 4 is aligned with the center of the reticle 2. Also, A
The lens is also rotated so that the IS mark 3 coincides with the long axis of the reticle 2 (D in FIG. 4). In this state of alignment, the lens holder 7 is lowered to hold the test lens so as not to move. Thereafter, the marking device 9 is operated to perform the marking.

In the above embodiment, only the AXIS mark 3 is displayed. However, as shown in FIG. 5A, the alignment completion sign 40 is displayed when the axial direction of the lens to be inspected coincides with the mark angle. You may make it. The display of the alignment completion sign is effective when the resolution of the display screen is low. Also, the AXIS mark 3 is not necessarily linear, but only needs to specify the axial direction in relation to the reticle 2, and the movement direction is designated as shown in FIG. 5B. Is also good. Thus, it is clear that the present embodiment can be variously modified, and these modifications are included in the present invention as long as the technical idea is the same.

[0015]

According to the present invention, it is possible to provide a lens meter capable of relieving an examiner from troublesome and inefficient work and easily marking a mark.

[Brief description of the drawings]

FIG. 1 is an external view of a lens meter according to the present embodiment.

FIG. 2 is an arrangement diagram of an optical system of a lens meter.

FIG. 3 is a block diagram showing a control system.

FIG. 4 is an explanatory view showing the state of alignment, wherein A indicates when the power is turned on, B indicates the setting of the mark angle, C indicates the execution of the alignment, and D indicates the completion of the alignment.

FIG. 5 is a modification showing the state of alignment, wherein A indicates the time of completion of alignment, and B indicates the time of execution of alignment.

[Description of Signs] 1 Display 2 Reticle 3 AXIS Mark 4 Target 10 AXIS Switch 10 'Auxiliary Switch

Continuation of the front page (56) References JP-A-61-200441 (JP, A) JP-A-3-833841 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 11 / 00-11/02

Claims (2)

(57) [Claims] 1. An automatic lens meter for automatically measuring optical characteristics such as spherical power and astigmatic power of a test lens inserted into a measurement optical system, wherein the optical center of the test lens with respect to the optical axis of the measurement optical system is provided. And the direction of the astigmatic axis
Detection means for detecting based on measurement by a constant optical system, and a display for displaying a reticle for alignment,
A mark indicating the direction of the astigmatic axis with respect to the direction of the mark point at the mark point
Input means for inputting a point angle, the indicia point angle which is the input
And displays a mark indicating superimposed on said reticle, be provided with a display a display control means for displaying the target for <br/> alignment showing the direction of the optical center and the astigmatic axis on the display based on said detecting means An automatic lens meter. 2. An automatic lens meter according to claim 1, whether further measured direction of the cylinder axis coincides with the mark point angle
Automatic lens meter, characterized in that it comprises monitoring means for monitoring whether, and informing means for informing a monitoring result to the operator.