JPS574533A - Detecting method of astigmatism - Google Patents

Detecting method of astigmatism

Info

Publication number
JPS574533A
JPS574533A JP7926080A JP7926080A JPS574533A JP S574533 A JPS574533 A JP S574533A JP 7926080 A JP7926080 A JP 7926080A JP 7926080 A JP7926080 A JP 7926080A JP S574533 A JPS574533 A JP S574533A
Authority
JP
Japan
Prior art keywords
scanning
astigmatism
regions
horizontal scanning
central region
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP7926080A
Other languages
Japanese (ja)
Other versions
JPS6314811B2 (en
Inventor
Takeshi Sato
Shunichi Suzaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NICHIDENSHI TEKUNIKUSU KK
NICHIDENSHI TECHNICS KK
Original Assignee
NICHIDENSHI TEKUNIKUSU KK
NICHIDENSHI TECHNICS KK
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NICHIDENSHI TEKUNIKUSU KK, NICHIDENSHI TECHNICS KK filed Critical NICHIDENSHI TEKUNIKUSU KK
Priority to JP7926080A priority Critical patent/JPS574533A/en
Publication of JPS574533A publication Critical patent/JPS574533A/en
Publication of JPS6314811B2 publication Critical patent/JPS6314811B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/02—Testing optical properties
    • G01M11/0228—Testing optical properties by measuring refractive power

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Optical Devices Or Fibers (AREA)

Abstract

PURPOSE:To detect and correct astigmatism with a simple constitution, by a method wherein for the central region of the regions formed by dividing a scanning period into three or more odd number, a constant signal, not varying in time with scanning, is applied to an astigmatism-regulating four-pole lens. CONSTITUTION:When the output of a variable DC resistor 16 is regulated to zero, and interlocking switches 21 and 22 are connected to contacts (a), the saw tooth- shaped horizontal scanning signal from a horizontal scanning power source 7x is also applied to clipping circuits 15a and 15b of given positive and negative clip voltages respectively, and through an adding circuit 17, one horizontal scanning period is divided into three or more odd-numbered horizontal scanning regions. A constant scanning voltage is generated for the central region, while scanning voltages varying with scanning are generated for the regions on both sides thereof, and said voltages are applied to an astigmatism-regulating four-pole lens 14x of an electron miroscope 1. When the resistor 16 is regulated, the central region of the regions formed by dividing one horizontal scanning period into three or the like is in focus, while the regions on both sides thereof are symmetrically out of focus. The same is the case with the vertical scanning direction. Also in the case of a large image surface, astigmatism can be reliably detected and corrected with a simple constitution.
JP7926080A 1980-06-12 1980-06-12 Detecting method of astigmatism Granted JPS574533A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7926080A JPS574533A (en) 1980-06-12 1980-06-12 Detecting method of astigmatism

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7926080A JPS574533A (en) 1980-06-12 1980-06-12 Detecting method of astigmatism

Publications (2)

Publication Number Publication Date
JPS574533A true JPS574533A (en) 1982-01-11
JPS6314811B2 JPS6314811B2 (en) 1988-04-01

Family

ID=13684879

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7926080A Granted JPS574533A (en) 1980-06-12 1980-06-12 Detecting method of astigmatism

Country Status (1)

Country Link
JP (1) JPS574533A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5218161A (en) * 1975-08-01 1977-02-10 Hitachi Ltd Sample scan type sample image display unit
JPS5222225A (en) * 1975-08-12 1977-02-19 Honda Motor Co Ltd Front wheel suspension device for car

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5218161A (en) * 1975-08-01 1977-02-10 Hitachi Ltd Sample scan type sample image display unit
JPS5222225A (en) * 1975-08-12 1977-02-19 Honda Motor Co Ltd Front wheel suspension device for car

Also Published As

Publication number Publication date
JPS6314811B2 (en) 1988-04-01

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