JP2936339B2 - LCD panel lighting system for camera - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid crystal panel lighting device for a camera, and more particularly to a liquid crystal panel lighting device for a camera using electroluminescence for a backlight of the liquid crystal panel.

[Prior Art and Problems to be Solved by the Invention] Conventionally, a liquid crystal panel illuminating device for a camera using electroluminescence for a backlight of a liquid crystal panel is disclosed in Japanese Patent Application Laid-Open No. 1-265237, a flash device having an electroluminescent element. As shown in the figure, a several volt battery is stepped up by a DC converter to generate a high-voltage DC power supply, which is applied to a flash member such as a xenon lamp as a load. This DC converter is a DC / AC inverter consisting of an oscillation circuit,
It is composed of a step-up transformer and a rectifying element, and charges a high-voltage DC rectified by the rectifying element to a capacitor to obtain a high-voltage DC power supply. When the charge charged in the capacitor is insufficient, the xenon lamp does not emit light.
The xenon lamp is not triggered until charging is completed. The light emission time and light emission amount of the xenon lamp are controlled by a computer in accordance with the opening and closing progress of the shutter, the luminance of the subject, and the distance.

Electroluminescence is a device in which a dielectric material and fluorescent particles are doped on a metal surface and a transparent electrode surface.
It emits light with an AC of ~ 5KHz. The mechanism of light emission is determined by the forbidden band (3.7 eV in ZnS) for the ultraviolet region of the substance that becomes the emission center, the insulating film material, and the dielectric material. The brightness does not increase.

Electroluminescence (EL) and xenon lamps have one AC load and the other DC load
When sharing the charged charge of the capacitor generated by the DC converter, wait for the completion of charging of the capacitor and freely take it out as an EL power source at any time, and use the DC / AC formed by an oscillation circuit, etc.
EL AC power can be obtained with an inverter.

However, when the charge of the capacitor is used as a shared power supply for the EL and the xenon lamp, there is a problem that the EL does not function as a backlight because the capacitor has not been charged depending on the charging speed and the discharge frequency.

[Object of the invention] The present invention has been made in view of the above-mentioned difficulties,
By using one of the multiple ACs converted by the DC / AC inverter as the flash means and the other as the power source for electroluminescence, it integrates multiple transformers conventionally provided for each and reduces the frequency of use of the flash means. An object of the present invention is to provide a liquid crystal panel lighting device for a camera that can emit electroluminescence without being affected.

It is another object of the present invention to provide a camera liquid crystal panel lighting device capable of reducing the number of components.

[Means for Solving the Problems] A camera liquid crystal panel lighting device according to the present invention includes a DC power supply, first and second DC / AC inverters for converting a DC power supply into first and second alternating currents, First, the first and second alternating currents output from the second DC / AC inverter are input to the primary side, and the third and fourth alternating currents obtained by transforming the first and second alternating currents from the secondary side are output to the primary side. It comprises a transformer for outputting, rectifying means for rectifying the third AC to generate a high-voltage DC power supply, flash means for loading the rectifying means, and electroluminescence for emitting light with the fourth AC.

In addition, a liquid crystal lighting device for a camera according to the present invention includes a DC power supply, a DC / AC inverter that converts the DC power supply into AC, and an AC output from the DC / AC inverter input to a primary side, and a secondary side. A transformer that generates an AC that is transformed into voltage, first and second output terminals provided at different points on the secondary side of the transformer, and a high-voltage DC that rectifies the AC output from the first output terminal. Rectifying means for generating a power supply;
A flash unit serving as a load of the rectifying unit; and an electroluminescence device that emits AC power from the second output terminal.

[Embodiment] An embodiment of a camera liquid crystal panel illuminating device according to the present invention will be described below in detail with reference to FIGS.

The liquid crystal panel device EQn for a camera according to the present invention has (n = 1)
When 2, hereinafter strobe, referred luminescence circuit) has a pin _P 1 to P ₁₀ as shown in FIG. 1, the pin _{P 1} and P
Reference numeral ₂ denotes connection lines W ₁ and W _2, which are CPU terminals 20 a and 20 b and a pin P
₃ and P ₄ are strobe power switches formed with normally open contacts
One end of each of SW _{3 and} EL switch SW ₄ and P ₅ , P
_7, P ₆ is connected to one and the other electrode and the trigger electrode of the xenon tube 4.

Also, pins P ₉ and P ₈ are connected to the terminals 8 a and 8 b of the EL panel 8 for the strobe and luminescence circuit EQ ₁ , and X for the strobe and luminescence circuit EQ ₂ of the other embodiment.
As shown by the dotted lines, pins P ₈ and P ₉ are connected to EL panel 8 respectively.
Terminals 8a, cross wiring 8b, and cutting the wiring shown in Y _1, performs wiring shown by Y _2.

Further, the other ends of the strobe power switch SW ₃ and the EL switch SW ₄ are connected to the (−) side of the battery 19 via a main switch SW ₄ formed by a normally open contact. The CPU 20 operates the light emitting diode LED, the light projecting lens LNS ₁ , the light receiving lens LNS ₂ , the AF unit 11 having the position detecting element PSD, the light measuring circuit 12 having the light receiving element 12 a, the date unit 13, and the drive circuit 15 by operating the relays button 14. Control. Drive circuit 15 is CPU2
By the control of 0, the film winding circuit 16, the shutter 17, and the lens 18a of the mirror copper 18 are driven via the terminals 15a, 15b, 15c.

Flash luminescence circuit EQ _1, as shown in FIG. 2, has a flash circuit SQ ₁ and EL circuit SQ _2, coil L ₁
~L ₆ is a shared transformer 1 which is connected in common with the flash circuit SQ ₁ and EL circuit SQ ₂ to the terminal T ₁ through T _10.

Sharing the terminal T ₁ of the transformer 1 is connected (+) side terminal 19a of the battery 19 via the pin P ₁₀ is the other end of the resistor R ₃ having one end connected to the terminal T ₁ to the terminal T ₃ Is connected. The terminal _{T 4} is connected to the pin _{P 3} through the capacitor _{C 3.} Furthermore, terminals T ₄ and T ₅ are both connected via pin P ₁
The CPU20 of the terminal 20a is connected to one end of the flash charging switch SW ₃ which is formed in a conventional contact.

The base of the strobe NPN transistor 5 and the terminal T _4, the collector and the terminal T _2, the emitter is connected to the pin P _3.

The terminal T ₅ of the common transformer 1 flash circuit SQ ₁
The cathode of the rectifying diode D _1, the pin P ₅ via the anode, also to connect the other end of the capacitor C ₁ having one end connected to the pin P ₅ the pin P _7. Further, resistors R ₁ and R ₂ and a charged neon tube 3 connected in series are inserted between the pins P ₅ and P ₇ .

Further, a coil L ₇ provided between the terminals 2a, 2b and 2c, 2d,
The terminals 2a of the trigger coil 2 having L ₈ resistors _{R 1} and _{R 2}
And the connection point, terminals 2b and 2d and the pin P _2, the terminal 2c pin P
_6, each terminal 2a at both ends of the capacitor _{C 2,} the pin P
Connect with ₇ . Furthermore, the pin P ₂ is connected to one end of the flash trigger switch SW ₂ through the terminal 20b of the CPU 20. The other ends of the flash trigger switch SW ₂ and the flash charge switch SW ₁ is connected to the pin P _3, the pin P ₃ is flash power switch SW _3, the battery through the main switch SW ₅ 19
To the terminal 19b of the terminal 19 of FIG.

Terminal T ₇ through T ₁₁ shared transformer 1 at terminal belonging to the EL circuit SQ _2, the main switch SW ₁ and the terminal T ₉ are stacked through a stroboscopic power switch SW ₄ which are formed via a pin P ₄ in the normally open contact one end of the terminal _{T 7} the pin _{P 9} via a capacitor _C 4, _{C 5,} which are connected in series with the terminal T _10, the terminal T ₁₁
Is connected to the terminal 8b of the EL panel 8 through a pin P _8, the terminal 8a of the EL panel 8 is connected to the pin P ₉ and the other end of the capacitor C ₆ having one end connected to the pin P _8.

The collector of the EL for NPN transistor 6 and the pin P ₉ one end to the connection point of the capacitor C ₄ and C ₅ which are connected in series with the other end of the resistor R _5, which are connected, emitter resistors R
₄ and terminal _{T 8} via the base is connected to one end of resistor _{R 5.}

Strobe and luminescence circuit EQ in another embodiment
_1, as shown in FIG. 3 includes a flash circuit SQ ₃ and the EL circuit SQ _4, the coil L ₁₁ ~L ₁₄ the terminal T ₁₁ ~T _14, T ₁₅ and T _17, T ₁₇
A flash circuit EQ ₃ a connected shared transformer 10 to T ₁₆ and
Shared by EL circuit SQ _4.

Flash circuit SQ ₃ and SQ ₁ terminals T ₁₁ through T ₁₄ and T ₁₆ except that read as terminal T ₁ through T ₄ and T ₆ shared transformer 1 shown in FIG. 2 shared transformer 10 the same connection with the same part Do. The terminal T ₁₇ of the common transformer 10 is connected to a rectifying diode D.
₁ is connected to the cathode. Further, the terminal T ₁₅ of the common transformer 10 to terminal 8b of the EL circuit SQ ₄ via a pin P _8, the terminal 8a
Between the pin P ₉ via a resistor R _12, the terminals 8a and 8b of the resistor R ₁₁ and capacitor C ₁₁ interpolated. The pin P ₄ connected to the pin P ₉ is connected to the pin P ₃ through the EL switch SW _4.

[Operation of the Invention] In the above configuration of the electronic flash, flash power switch SW ₃ and the main switch SW ₅ the flash circuit SQ ₁ and SQ ₃ luminescence circuit EQ ₁ and EQ ₂ is formed by normally closed contacts of the CPU20 after being closed and the flash charge switch SW ₁ is opened, resistor R _3, a capacitor C _3, and oscillation strobe NPN transistor 5 with a time constant due to the inductance of the coil L _1, L _2, charging the high-voltage DC charge to the capacitor C ₁ I do. Capacitor _{C 1} is the terminal _{T 6} (T ₁₆₎ side is (+) charge. When the charging is completed, the charged neon tube 3 is ignited.
CPU20 controlled by the xenon tube 4 when the flash trigger switch SW ₂ which is formed by the normally open contact is closed it is through a pin P ₆ a trigger pulse by the coil L _7, L 8 of Torigakoiri 2 _{(L 15,} L ₁₆₎ As the trigger is applied to the electrodes, the xenon tube 4 flashes.

The EL switch SW ₄ to the oscillating EL for NPN transistor 6, EL circuit SQ ₂ is closed, since the EL circuit SQ flash charge switch SW ₁ also continues after the completion of charging in ₄ is turned open by a mom, Strobe NPN transistor 5 oscillates and EL
The panel 8 emits light.

In any case, the EL circuits SQ ₁ and SQ ₂ can always emit light from the EL panel 8 including the charging operation of the capacitor C ₁ except for the moment when the xenon tube 4 is flashing.

[Effects of the Invention] A liquid crystal panel lighting device for a camera according to the present invention includes: a DC power supply; first and second DC / AC inverters for converting the DC power supply into first and second alternating currents; Second DC / AC
A transformer for inputting the first and second alternating currents output from the inverter to a primary side and outputting third and fourth alternating currents obtained by transforming the first and second alternating currents from a secondary side; A rectifying means for rectifying the alternating current of No. 3 to generate a high-voltage DC power supply, a flash means serving as a load on the rectifying means, and an electroluminescence device for emitting light by the fourth alternating current. And the transformer for electroluminescence can be integrated. In addition, there is an effect that electroluminescence can be emitted as needed without being affected by the frequency of use of the flash means.

In addition, a liquid crystal lighting device for a camera according to the present invention includes a DC power supply, a DC / AC inverter that converts the DC power supply into AC, and an AC output from the DC / AC inverter input to a primary side, and a secondary side. A transformer that generates an AC that is transformed into voltage, first and second output terminals provided at different points on the secondary side of the transformer, and a high-voltage DC that rectifies the AC output from the first output terminal. Rectifying means for generating a power supply;
Since it is provided with flash means serving as a load of the rectifying means and electroluminescence which emits by alternating current outputted from the second output terminal, only one DC / AC inverter is required, and There is an effect that various parts can be reduced, for example, the oscillation circuit can be omitted.

[Brief description of the drawings]

FIG. 1 is a block diagram of a camera liquid crystal panel lighting device according to the present invention, and FIGS. 2 and 3 are circuit diagrams of one embodiment and another embodiment of a camera liquid crystal panel lighting device, respectively. 1 Shared transformer (transformer) 4 Xenon tube (flash means) 5 NPN transistor for flash (first DC / AC inverter) 6 NPN transistor for EL (second DC / AC inverter) 8 EL panel (electroluminescence) 10 Shared transformer (transformer) 19 Battery (DC power supply) D ₁ Rectifier diode (rectifier) T ₁₅ Second output terminal, T ₁₇ 1 output terminal

Claims (2)

(57) [Claims] 1. A DC power supply, first and second DC / AC inverters for converting the DC power supply into first and second alternating currents, and outputs from the first and second DC / AC inverters. A transformer for inputting the first and second alternating currents to a primary side and outputting third and fourth alternating currents obtained by transforming the first and second alternating currents from a secondary side, and rectifying the third alternating current; And a rectifying means for generating a high-voltage DC power supply, a flash means serving as a load on the rectifying means, and an electroluminescence device for emitting light by the fourth alternating current. 2. A DC power supply, a DC / AC inverter for converting the DC power supply into an AC, and an AC output from the DC / AC inverter being input to a primary side to generate an AC transformed to a secondary side. And a first transformer provided at a different location on the secondary side of the transformer.
A second output terminal; a rectifying unit that rectifies an alternating current output from the first output terminal to generate a high-voltage DC power supply; a flash unit serving as a load on the rectifying unit; and an output from the second output terminal. A liquid crystal panel lighting device for a camera, comprising: