JPS5630677A - Automatic luminance regulator - Google Patents

Automatic luminance regulator

Info

Publication number
JPS5630677A
JPS5630677A JP10703279A JP10703279A JPS5630677A JP S5630677 A JPS5630677 A JP S5630677A JP 10703279 A JP10703279 A JP 10703279A JP 10703279 A JP10703279 A JP 10703279A JP S5630677 A JPS5630677 A JP S5630677A
Authority
JP
Japan
Prior art keywords
luminance
transistor
display tube
power source
fluorescent display
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.)
Pending
Application number
JP10703279A
Other languages
Japanese (ja)
Inventor
Yoshiharu Nagahara
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP10703279A priority Critical patent/JPS5630677A/en
Publication of JPS5630677A publication Critical patent/JPS5630677A/en
Pending legal-status Critical Current

Links

Landscapes

  • Electric Clocks (AREA)
  • Indicating Measured Values (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

PURPOSE: To vary the luminance of a display tube according to a ambient brightness with a simple construction by applying voltage between the collector and the emitter of a luminance reglating transistor to the base thereof after it is divided with a photo detector and a resistance.
CONSTITUTION: Transistors Q1 and Q2 for regulating luminance are connected in parallel between a filament F of a fluorescent display tube FL and one end of a smoothing capacitor C1 of a DC power source obtained by rectifying the commertial power source. A transistor Q3 switches on by a frequency of the commertial power source at a specified duty cycle to secure the minimum luminance of the fluorescent display tube FL. A voltage obtained dividing the voltage between the collector and the emitter of the transistor Q1 with a photo detector R3 and a resistance R4 is applied to the base of the tansistor to vary the level of energization of the transistor Q1 whereby the luminance of the fluorescent display tube is automatically changed according to the ambient brightness.
COPYRIGHT: (C)1981,JPO&Japio
JP10703279A 1979-08-22 1979-08-22 Automatic luminance regulator Pending JPS5630677A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10703279A JPS5630677A (en) 1979-08-22 1979-08-22 Automatic luminance regulator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10703279A JPS5630677A (en) 1979-08-22 1979-08-22 Automatic luminance regulator

Publications (1)

Publication Number Publication Date
JPS5630677A true JPS5630677A (en) 1981-03-27

Family

ID=14448781

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10703279A Pending JPS5630677A (en) 1979-08-22 1979-08-22 Automatic luminance regulator

Country Status (1)

Country Link
JP (1) JPS5630677A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5003300A (en) * 1987-07-27 1991-03-26 Reflection Technology, Inc. Head mounted display for miniature video display system
US5023905A (en) * 1988-07-25 1991-06-11 Reflection Technology, Inc. Pocket data receiver with full page visual display
US5048077A (en) * 1988-07-25 1991-09-10 Reflection Technology, Inc. Telephone handset with full-page visual display

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5003300A (en) * 1987-07-27 1991-03-26 Reflection Technology, Inc. Head mounted display for miniature video display system
US5023905A (en) * 1988-07-25 1991-06-11 Reflection Technology, Inc. Pocket data receiver with full page visual display
US5048077A (en) * 1988-07-25 1991-09-10 Reflection Technology, Inc. Telephone handset with full-page visual display

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