Unicos URK-700 Service manual

SERVICE MANUAL

AURO REF / KERATOMETER URK-700

Revision 1.01 UNICOS Co., Ltd. www.e-unicos.com

Before use this instrument, be sure to read this manual collectively.

CONTENTS

1. General

1.1 Features ············································································································· 1

1.2 Dimensions ········································································································· 2

2. Operational Description

2.1 Measurement Principle

2.1.1 Refractometry ······································································································ 3

2.1.2 Keratometry ········································································································· 4

2.2 Layout of Optical System ················································································ 6

2.3 Electrical System

2.3.1 Block Diagram ······································································································ 8

2.3.2 Electrical Wiring ································································································ 9

2.3.3 Eyeball Diagram Generated by the REF Measurement ················································· 10

3. Repair Guide

3.1 Disassembly and Adjustments

3.1.1 Disassembling of Covers ·······················································································11

3.1.2 Disassembling of LCD module················································································· 13

3.1.3 Disassembling of Main PCB ···················································································· 13

3.1.4 Disassembling of Optical head assembly ································································ 14

3.1.5 Disassembling of Printer ····················································································· 15

3.1.6 Disassembling of SMPS ·························································································· 16

3.1.7 Disassembling of Headrest ···················································································· 17

3.1.8 Slit and photosensor Space Adjustment ·································································· 18

3.2 Calibration

3.2.1 Refractometry calibration ···················································································· 19

3.2.2 Keratometry calibration ······················································································· 24

4. SERVICE PARTS LIST

4.1 OPTICAL HEAD ASS’Y ························································································· 29

4.2 LOWER BASE ASS’Y ···························································································· 29

ⅰ

4.3 JOYSTICK ASS’Y ································································································ 29

4.4 UPPER BASE ASS’Y ···························································································· 29

4.5 COVER ASS’Y ····································································································· 30

4.6 HEADREST ASS’Y ································································································ 30

4.7 ACCESSORY ASS’Y ······························································································31

1

1. General

1.1 Features

Refracometry

Vertex Distance(VD) 0.0, 10.0, 12.0, 13.5, 15.0 mm
Sphere Power(SPH) -25.00 ~+22.00 D (atthevertexdistanceof 12mm)

(Incrementsselectablebetween0.12and0.25D)

Cylinder Power(CYL) 0.00 ~ ±10.00 D

(Incrementsselectablebetween0.12and0.25D)
Axis(AX) 1 ~ 180˚ (Increments: 1˚)
Cylinder Form -, +, MIX

IOL Switch ○
Pupil Distance(PD) 10 ~ 85 mm
Minimum Pupil Diameter 2.0 mm

Eye fixation target Scene with a red roof house

Keratometry

Radius of curvature (Increment) 5.0 ~ 10.2 mm (Increments: 0.01mm)
Refractive power (Increment) 33.00 ~ 67.50 D (whencorneaequivalentrefractiveindexis1.3375)

(Incrementsselectable from0.05,0.12,0.25)

Astigmatism (Increment) 0.00 ~ -15 D (Incrementsselectable from0.05,0.12,0.25)
Axis (Increment) 1 ~ 180 (Increments: 1)
Cornea equivalent refractive index 1.3375, 1.332, 1.336

Measurement range Ø2.0mm
Contact lens base curve measurement ○

Other Features

PD measurement 10 ~ 85 mm
Corneal size measurement 2.0 ~ 12.0 mm (Increments: 0.1mm)

User key LCD monitor down side
Vertical movement of measurement head By rotation of operation lever
Stage sliding method Sliding lever

Stage lock Stage holding knob
TV camera Basis (Two-dimensional sensor)
Image position and focus adjustment Mechanical

LCD monitor 6.4 inches
Printing method, paper width Thermal, 58 mm
Measurement button Pushbutton switch

Power saving system Select OFF, 3 MIN, 5 MIN and 10 MIN
Clock ○
Stage movement range Right and Left: 903 mm, Back and forth: 503 mm

Measurement Head Vertical movable range 253 mm
Chin Rest Vertical Moving amout 553 mm

1

Dimension 248(W) 476(D) 475(H)mm
Weight Approximately 21 kg

2

1.2 Dimensions

3

2. Operational Description

2.1 Measurement Principle

2.1.1 Refractometry

(1) A ray of light from the light source is reflected in the retina of examinee.
(2) According to refraction of examinee’s eye, the reflected light in the examinee’s eye exits as follow.

1) In case of emmetropia, the ray of light is parallel.

2) In case of near-sightedness, the ray of light is convergence.

3) In case of a farsighted eye, the ray of light is divergence.
(3) Then, the ray of light through the optical system imaged in the camera as six spot.
(4) Calculate the distance of coordinate of six spots and the center, obtain SPH, CYL and AX value.

Objective Lens

Aperture

Light source

Myopia

Emmetropia

Division pattern

For measurement

CCD Camera

-D

Short axis

α

0D

Long axis

Hyperopia

+D

4

2.1.2 Keratometry

Observational Lens

Aperture for m

easuring

Mire Light Source

CCD Camera

Objective Lens for Keratoscope

Mire Light is reflected examinee’s cornea, is imaged on the camera after through the Optical System.
Circular Mire Light is reflected circular or ellipse form by Radius of curvature and Astigmia of Examinee
cornea, coordinates of refracted light (XY Coordinates) on the camera is inputted the MPU, calculate that
data and obtain the Radius of Circle or the major axis and the minor axis of ellipse, Angle of Rotation .

Y

Y

The major axis

The minor axis

The minor axis

The major axis

θ

θ

2b2a

2b2a

2

2

X

X

2

2

a

a

θ/2

θ/2

Optical Axis

Optical Axis

X

X

θ/2 h

θ/2 h

R

2

2

Y

Y

+

+

＝ R

＝ R

2

2

b

b

R

θ

θ

θ/2

θ/2

R, θ and h are correlated Snell’s Low as follows (R is radius of curvature of cornea, θ is incident angle
of Mire Light in the cornea, h is distance between position of Mire Light image at the cornea and Optical

Axis), obtain the long or short radius of curvature of cornea by this formula.

R ＝

h

sin(θ/2)

5

R, D and n are correlated as follows (R is radius of curvature of cornea, D is refractive power of the cornea,

1)

equivalent refractive index

＝

1.3375

,

,

n is refractive index of the cornea), obtain the diopter(D) of cornea by R, long or short radius of curvature
of the cornea..

D ＝

6

2.2 Layout of Optical System

7

Layout of Optical System

1: Examinee’s Eye
2-1, 2-2: External Led
3: Mire Ring Unit for Keratometry
4-1: Half Mirror
4-2: Half Mirror
4-3: Total Reflection Mirror
5: Objective Lens
6-1: Aperture Mirror
6-2: Aperture
7: Half Mirror
8-1: Aiming Light Source
8-2: Aiming Pattern
9: Light Source for Refractometry
10-1: Division Pattern
10-2: Prism Lens
11: Relay Lens
12: Camera for Refractometry
13: Coneal Relay Lens
14: Camera for Keratometry
15: Refractive Poser Revision Lens
16: Internal Chart
17: Internal Chart Illuminator

Route of Optical System

External illumination system: 2-1 2-1 1
System for the fogging method system: 1716 15 4-34-24-11
Keratometry system: 3 14-14-2 1314
Refractometry system: 9 7 6-2 6-154-114-1 5 6-1 10-1 10-211 12
Automatic measurement system: 3 1

8

2.3 Electrical System

2.3.1 Block Diagram

9

2.3.2 Electrical Wiring

10

2.3.3 Eyeball Diagram Generated by the REF Measurement

It is possible to print the refrection state diagram regarding the result of the REF measurement to the
internal printer. This function will be performed when ‘PRINT=ALL’ in the Page 2/5 of the SETUP MODE.
See the following table and diagram for further information.

Classification of Data NOT NEA FAR AS
Emmetropia -0.5 S +0.5 -0.5 C  0.0 ◎
Myopia S < -0.5 -0.5 C  0.0 ◎
Simple Myopic

-0.5S 0.0 C < -0.5 ◎ ◎

Astigmatism
Compound
Myopic

S < -0.5 C < -0.5 ◎ ◎

Astigmatism
Mixed

0.0 < S C < -0.5 S+C < 0.0 ◎

Astigmatism
Hyperopia +0.5 < S -0.5 C  0.0 0.0 < S+C ◎

Simple Hyperopic

+0.5 < S C < -0.5

Astigmatism

0.0 S+C 

◎ ◎

+0.5

Compound
Hyper-

opic

+0.5 < S+C ◎ ◎

Astigmastism

Table Eyeball Output by REF Measurement

Emmetropia / Normal Mixed Astigmatism

Myopia / Near Sightedness Hyperopia / Far Sightedness

Simple Myopic Astigmatism Simple Hyperopic Astigmatism

11

Compound Myopic Astigmatism Compound Hyperopic Astigmatism

Figure Diagram of the eye ball output by REF Measurement

12

3. Repair Guide

3.1 Disassembly and Adjustments

3.1.1 Disassembling of Covers

3.1.1.1 Joystick decoration (A)

1) Remove the Joystick decoration

3.1.1.2 Stage holding knob (B)

1) Remove the Stage holding knob

3.1.1.3 Main cover-L (D)

1) Remove the seven caps (C) and seven screws ①

3.1.1.4 Main cover-R (F)

1) Remove the seven caps (E) and seven screws ②

2) Remove the head left cover claw as pushing down the cover (2 point)

3) Remove the Printer cable connector

3.1.1.5 Rear cover (H)

1) Remove the two caps (G) and two screws ③

2) Remove the external led connector

11

12

3.1.2 Disassembling of LCD module

3.1.2.1 LCD module (A)

1) Remove the connectors

2) Remove the fourscrews ① and then remove the LCD module

3.1.2.2 LCD monitor (B)

1) Remove the three screws ③

2) Remove the fourscrews ④ & LCD Bracket ⑤

3.1.2.3 Remove the LCD window (D)

3.1.2.4 User key module (E)

1) Remove the four screws ⑥

13

3.1.3 Disassembling of main PCB (A)

1) Remove the connectors

2) Remove the fourscrews ① and then remove the main PCB

14

15