JPS55542A - Light quantity control unit - Google Patents
Light quantity control unitInfo
- Publication number
- JPS55542A JPS55542A JP113179A JP113179A JPS55542A JP S55542 A JPS55542 A JP S55542A JP 113179 A JP113179 A JP 113179A JP 113179 A JP113179 A JP 113179A JP S55542 A JPS55542 A JP S55542A
- Authority
- JP
- Japan
- Prior art keywords
- light
- photo detector
- led
- control unit
- decreases
- 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
Links
Landscapes
- Exposure Or Original Feeding In Electrophotography (AREA)
Abstract
PURPOSE:To miniaturize the light quantity detecting part without limiting the installation position of a photo detector by receiving the light of the sub light source which is driven by the electric power corresponding to the electric power for light source with the photo detector and applying the receiving light signal thereof to the control unit thereby controlling the quantity of light. CONSTITUTION:The LED 31 of the light quantity detecting part 30 is parallel-connected to an exposure lamp 10 whose emission quantity is controlled by ignition phase control of an SCR 20 and is let to emit light at the quantity proportional to the terminal voltage of the lamp 10. A photo detector 32 receives the light of the LED 31 and sends its output signal to a control unit 40. When the supply voltage decreases, the emission quantity of the exposure lamp 10 and LED 31 decreases. The incident light quantity to the photo detector 32 decreases and its resistance value increases, hence the base-emitter voltage of a transistor 47 increases and the charging current to a capacitor 52 flowing through a resistance 51 and the emitter- collector of the transistor 47 increases. This results in the shortened time until a PUT 53 conducts, expedited ignition phase of the SCR 20, increased power supply to the exposure lamp 10 and increased emission quantity.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP113179A JPS55542A (en) | 1979-01-08 | 1979-01-08 | Light quantity control unit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP113179A JPS55542A (en) | 1979-01-08 | 1979-01-08 | Light quantity control unit |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP50007567A Division JPS5182630A (en) | 1975-01-16 | 1975-01-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS55542A true JPS55542A (en) | 1980-01-05 |
Family
ID=11492882
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP113179A Pending JPS55542A (en) | 1979-01-08 | 1979-01-08 | Light quantity control unit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS55542A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6113800U (en) * | 1984-06-29 | 1986-01-27 | 信一 久末 | Fall prevention device for cylinder ladders |
JPS6450599U (en) * | 1987-09-25 | 1989-03-29 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4911347A (en) * | 1972-05-24 | 1974-01-31 |
-
1979
- 1979-01-08 JP JP113179A patent/JPS55542A/en active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4911347A (en) * | 1972-05-24 | 1974-01-31 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6113800U (en) * | 1984-06-29 | 1986-01-27 | 信一 久末 | Fall prevention device for cylinder ladders |
JPH0430316Y2 (en) * | 1984-06-29 | 1992-07-22 | ||
JPS6450599U (en) * | 1987-09-25 | 1989-03-29 |
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