JP3429109B2 - 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 optical characteristics of a lens, and more particularly to a lens meter suitable for measuring addition of progressive lenses.

[0002]

2. Description of the Related Art A measuring light beam is projected onto a lens to be measured, and the locus of the measuring light transmitted through the lens to be detected is detected by a light receiving element,
There is known a lens meter capable of obtaining the optical characteristics of the lens under test based on the detection result. This lens meter is equipped with an add power measuring mode to measure the add power of a progressive multifocal lens or the like. In the add power measurement mode, the lens to be inspected is moved with respect to the measurement optical axis to first measure and store the distance portion. After that, the lens is moved along the progressive zone, and the position determined by the measurer to reach the near portion is measured and stored.
The addition is calculated from the difference between these two measurements.

[0003]

Since the lens before being framed is marked at each position of the distance portion and the near portion, the measurer moves the lens according to the mark. Can be measured. However, since this mark is wiped off by the lens after the frame is put in, it is difficult for an unskilled measurer to find the distance portion and the near portion and accurately measure them, and the measurement is difficult. I had to take time. Among recent devices, there is a device that informs the measurer of each position of the distance portion and the near portion by displaying a guide mark or the like, but even if the guide mark or the like is followed, A measurer who is not aware of the entire measurement process may lose sight of which stage of measurement is currently being performed. In this case, there is a problem that the measurement will take time if the measurement process is repeated from the first measurement process. In view of the above problems of the conventional apparatus, it is a technical object of the present invention to provide a lens meter which allows even an unskilled measurer to efficiently and easily measure addition power.

[0004]

In order to solve the above problems, the present invention is characterized by having the following configuration. (1) Operate the progressive-focus lens whose position of the distance measurement part and the near measurement part is unknown according to the guidance display such as guidance marks.
And has a mode switching means for switching the additional power measurement mode for measuring the diopter, the projected measuring light beam to the sample lens by the measurement optical system, the measuring light beam transmitted through the sample lens formed
In a lens meter that measures the optical characteristics of the lens under test by detecting the image to be detected with a light receiving element, the measurement process in the addition measurement mode should be divided, and the test lens should move during each measurement process.
With a symbolized illustration with a mark indicating the direction
Display multiple illustrations according to the order of the process
Step display means for displaying side by side , based on the measurement result or measurement value read signal by the measurement optical system, transition signal generating means for issuing a transition signal from one measurement step to the next measurement step, and based on the transition signal Shows the current measurement process
And an instruction means for instructing the illustration .

(2) The lens meter of (1) is further
Select whether to display the process by the process display means
A lens meter, comprising:

[0006]

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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. Reference numeral 1 is a display such as an LCD, which displays various measurement information such as marks for alignment and measurement results. A switch group 2 has a switch function corresponding to the switch display 3 displayed at a predetermined position on the display 1. The switch display 3 is a mode for switching to a left / right selection switch display, a print switch display, and an addition degree measurement mode.
It has various switch displays such as a mode changeover switch display and a menu switch display for setting parameters. When the menu switch display is pressed, the switch display 3 is further switched to various parameter switch displays. Reference numeral 4 is a READ switch for reading and storing the measured value.

Numerals 10 and 11 are accommodating portions of a measuring optical system, which will be described later, and the accommodating portion 10 side is provided with a lens for mounting a lens.
A spise 12 is provided and holds the lens to be inspected by lowering the lens retainer 13. Reference numeral 14 is a lens pedestal, and the lens pedestal 14 is held so as to be movable back and forth.
Reference numeral 15 is a moving lever of the lens pedestal 14.

FIG. 2 is a diagram for explaining the optical system and control system of the lens meter. 20 is a measurement light source such as an LED,
Four condenser lenses 21 are arranged in the vicinity of the focal point of the condenser lens 21 at right angles to the optical axis, and are sequentially turned on at the time of measurement by the control of the microcomputer. Reference numeral 22 is a measurement target having slits orthogonal to each other, and includes a condenser lens 21 and a collimator.
It is arranged near the focal point of the towing lens 23 so as to be fixed or movable. The nose piece is arranged near the focal points of the collimating lens 23 and the imaging lens 24. Reference numeral 25 is a half prism, and reference numeral 26 is two one-dimensional image sensors which are provided orthogonally to the optical axis and are arranged so that their detection directions are orthogonal to each other. The light from the measurement light source 20 illuminates the measurement target 22 via the condenser lens 21. The light flux that has passed through the measurement target 22 passes through the collimating lens 23, the lens L to be tested, and the imaging lens 24, and two image sensors 26 that are orthogonal to each other.
Image on top, respectively.

The relationship between the refractive power of the lens to be inspected and the image formation position of the measurement target will be briefly described. Each measurement light source 2
The measurement targets are individually illuminated with the lighting of 0 sequentially. If there is no lens to be inspected (or if a lens having no refractive power is mounted), the target images formed on the image sensor 26 by turning on the respective measurement light sources are all overlapped. When the lens to be inspected has only spherical refractive power, the position of the target image on the image sensor 26 moves by an amount corresponding to the spherical refractive power. When the lens to be inspected has only the cylindrical surface refractive power, the light flux incident on the lens has a refractive power in a direction (or the same direction) orthogonal to the main radial line. Therefore, the spherical power, the astigmatic power, the astigmatic axis angle, and the prism amount can be obtained based on the center coordinates of the target image obtained by turning on each measurement light source 20. Regarding this calculation, Japanese Patent Laid-Open No. 60-17 filed by the same applicant as the present invention.
Since it is basically the same as No. 335 (the title of the invention, "Autrens meter"), please refer to it.

The output signal from the image sensor 26 is processed by the signal detection processing circuit 30 and input to the microcomputer 31. Microcomputer 3
1 obtains the optical characteristics of the lens L to be tested by performing a predetermined calculation process. Reference numeral 32 is a display circuit of the display 1, and 33 is a drive circuit of the measurement light source. Reference numeral 34 is a printer, and 35 is a drive circuit thereof.

The operation of the apparatus having the above configuration will be described. First, the measurement mode of the single focus lens will be briefly described. The monofocal lens measures spherical power, astigmatic power, astigmatic axis angle, and the like. Microcomputer 3
1 controls a display circuit 32 to display a reticle for measuring a single focus lens on the display 1 (not shown). Further, the micro computer 31 sequentially turns on the four measurement light sources 20 via the drive circuit 33. When the lens to be inspected having a refractive power is placed on the nose piece 12, the refractive power is calculated and displayed on the display 1, and
The deviation amount from the optical axis of the lens to be inspected is calculated from the obtained prism value, and the cross target is displayed on the reticle on the display 1 at a position corresponding to the deviation amount. The measured value when the reticle and the cross target have a predetermined relationship is the measured value of the lens under test. By pressing the READ switch 4, the measured value is stored.

Next, the measurement of the framed progressive multifocal lens will be described. The examiner selects the switch 2 corresponding to the display indicating the progressive multifocal lens measurement in the switch display 3.
Press to enter the progressive multifocal lens measurement mode. When the lens to be inspected is not placed, the screen on the display 1 is shown in FIG. 3 (the switch display 3 is not shown).
As shown in FIG. 5, an alignment circle 40 having two curves simulating a progressive lens and a guide 41 are displayed.
In the lower part of the screen, four measurement process illustrations 42 (the explanation of each process will be described later) that symbolizes the measurement process for performing progressive multifocal lens measurement are displayed. Left and right measurement values are displayed in the portions 44 and 45. Press the switch for left / right selection in the switch group 2 to specify the left / right of the lens to be measured, and with the lower side of the frame in contact with the lens holder 14 as shown in FIG. Place the test lens on the nose piece. The lens to be inspected is placed slightly above the center on the nose piece and the measurement is started.

(A) First measuring step The first measuring step is a step of placing the distance portion on the vertical axis passing through the optical center of the lens. When the lens to be inspected is positioned on the measurement optical axis, the progressive target 46 is displayed on either side of the guide 41 (a in FIG. 4). The guide 41 indicates the movement target on the reference vertical axis, and the position of the progressive target 46 indicates the direction in which the lens under test should be moved. At this time, the arrow display pointing to the left and right of the measurement process illustration 42a is displayed in a blinking manner, and the blinking display of this arrow indicates the first measurement process for moving the lens to be tested left and right.

The microcomputer 31 determines the relative position of the progressive target 46 with respect to the guide 41 as follows based on the prism value at each measurement point. If the lens to be inspected has only spherical power, the distance portion of the lens is located on the axis where the left and right prism values become almost 0. Control the position of Get 46. When the lens to be inspected has a cylindrical surface refractive power, the position where the prism value becomes 0 in the left-right direction of the lens to be inspected is on the astigmatic axis, so the effect of the cylindrical surface refractive power is determined from the prism value at each measurement point. Then, the position of the target 46 is controlled based on the correction result. Regarding the correction processing of the influence due to the refracting power of the cylindrical surface, Japanese Patent Application Laid-Open No. 6-58842 (the title of the invention: "lens
Data and its measurement method ”). The examiner moves the lens in the left-right direction so that the target 46 is located in the center of the guide 41 (in FIG. 4A, the lens is moved in the left direction toward the apparatus).

(B) Second measurement step The second measurement step is a step of finding a distance portion on the reference vertical axis and measuring and storing it. When the center of the program target 46 aligns with the guide 41, the alignment circle 40
"PUS" that means to move the lens to the inside
A guide mark "H ↑" appears (b in FIG. 4). At this time, in the measurement process illustration 42, the arrow portion under the graphic of 42b is switched to blinking display to inform the examiner that it is the second measurement process. The examiner moves the lens toward the back side according to the guidance display. The device continuously obtains measured values at predetermined intervals, and if there is no change in addition with movement, “PUSH ↑” on the screen is erased, the guide 41 is displayed in a large cross, and the measurement point is far away. Notify the examiner that you are in the office. After that, when the measured value stabilizes for a predetermined time (for example, 1 second), the measured value at this time is automatically read and stored.

(C) Third measuring step The third measuring step is a step of inserting the measuring point into the progressive portion. When the measurement value of the distance portion is stored, the addition power is automatically measured. In the alignment circle 40, "PULL ↓" which means that the lens is moved to the front side is displayed, and an addition graph 50 appears at the lower right of the alignment circle 40 (c in FIG. 4). ). The measurement process illustration is
The arrow below the figure of 42c changes to blinking display,
Notify the examiner that it is a measurement process. The examiner follows the guidance display and slowly moves the lens toward you.

While the lens is moving, the apparatus continuously obtains measured values, and the moving distance is converted from the prism amount of the lens,
The addition start position is detected from the addition change per unit movement amount. Further move the lens to determine whether or not a predetermined addition power (for example, 0.4D) or more can be obtained from the addition start position. If it is obtained, check that the measurement point is in the progressive section. (The addition diopter is usually 0.5 D or more, so by detecting the addition diopter close to this, the measurement point can be reliably placed in the progressive portion).

(D) Fourth measuring step The fourth measuring step is a measuring step for obtaining the addition power. When the measurement point enters the progressive part and this is confirmed, "PULL
The display of "↓" disappears and the coronata-get 51 appears. At this time, in the measurement process illustration, the arrow portion under the figure of 42d is switched to blinking display to notify the examiner that the fourth measurement process has been started. The examiner puts the near part in the measurement position,
Pull the lens toward you. When the lens moves along the progressive portion, the corona target 51 moves upward on the alignment circle 40. The movement of the corona target 51 is performed by converting the change in the prism amount in the vertical direction of the lens into the movement amount. While moving the progressive portion, the device continuously measures and displays the addition power on the screen and the addition graph 50 showing the increase. In addition, the device detects a change in the astigmatic power and monitors the measurement position so as not to deviate to the left and right of the progressive portion.

The examiner further pulls the lens toward you and searches for the near portion. When it comes near the near portion, the near portion sign 52 appears around the moving corona target 51 (e in FIG. 4). The near portion sign is displayed when it is determined that the measurement position has reached a predetermined distance from the addition start position. In the device of this embodiment, this predetermined distance is, for example, about 16 mm. This is because the near portion position of the progressive lens is not constant depending on the lens type and the like, but in the standard progressive multifocal lens, it is set around 16 mm from the addition start position. The distance is simply calculated based on the change in the prism amount. The position at which the near vision sign appears from the addition start position may be changed and set by the examiner by the menu setting switch of the device according to the type of lens. Further, when the maximum addition power (that is, the near portion position) is obtained from the continuously measured measurement results before the measurement position reaches the predetermined distance, the near portion sign 52 is displayed at that position. You may do it. Within the range where the near part sign 52 is displayed, when the addition power reaches the maximum and stabilizes, RE
Press AD switch 4. The device stores the addition power obtained at this time.

As described above, during the measurement of the progressive power multifocal lens, all the measurement processes and the current measurement process are displayed, so that the examiner can grasp the entire measurement procedure, and at any time during the measurement. It is possible to recognize whether the step is being performed, and it is possible to proceed with the measurement without getting lost in the lens moving operation. Even if the lens moving operation is mistaken, it is possible to quickly return according to the measurement process display. In addition, the measurement process is displayed as a pattern illustration, so it is easy to visually recognize. Furthermore, since the moving direction of the lens is also displayed in each measurement step, an examiner who is unfamiliar with the measurement can easily perform the measurement. Note that the progressive mode lens measurement mode
When it is not necessary to display the measurement process illustration 42, for example, in the case of a trained examiner, the display can be selected on the setting screen.

[0022]

As described above, according to the present invention,
Even an unskilled measurer can recognize the entire measuring procedure of the progressive power multifocal lens, accurately perform the lens movement operation, and efficiently and easily measure the addition power.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating an optical system and a control system of a lens meter according to an embodiment.

FIG. 3 is a diagram showing an example of a screen on the display 1 in a state where a lens to be inspected is not placed.

FIG. 4 is an explanatory diagram showing a display on a display 1 in a progressive mode lens measurement mode.

[Explanation of symbols]

1 display 2 switch group 3 switch display 20 Measurement light source 26 Image Sensor 31 Microcomputer 42 Measurement process illustration

Claims (2)

(57) [Claims] 1. A mode switching means is provided for switching to a diopter measuring mode for measuring a diopter by operating a progressive-focus lens in which the positions of the distance-measuring unit and the near-distance measuring unit are unknown, in accordance with a guidance display such as a guidance mark. , Adds measurement mode in the lens meter in which the measurement optical system projects the measurement light beam onto the lens to be measured, and the image formed by the measurement light beam transmitted through the lens to be detected is detected by the light receiving element to measure the optical characteristics of the lens to be measured. dividing the measuring step in, the subject lens is moved to each measurement step
Symbolized Ira with a mark indicating the direction to move
Stroke display and multiple illustrations in process order
According to the measurement result by the measurement optical system or the measurement value reading signal, the transition signal generating means for issuing a transition signal from one measurement step to the next measurement step, and based on the transition signal Current measurement engineer
A lens meter, comprising: an instruction means for instructing an illustration showing a distance. 2. The lens meter according to claim 1, further comprising:
Select whether to display the process by the process display means
A lens meter comprising a selection unit .