JPS5918635Y2 - electronic flash device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electronic flash device, and in particular transformers are thin and
This allows the overall volume of the device to be reduced in size.

2. Description of the Related Art Conventionally, electronic flash devices that use a flash discharge tube to emit light have been used in various fields, and among them, they are often used as artificial light sources for photography.

Electronic flash devices used for photography are desired to be as small as possible for convenient portability, and various improvements have been made so that they are now considerably smaller.

In addition, recently, devices that integrate both an electronic flash device and a camera have been developed and put into practical use, but integrating the two inevitably makes the entire device larger.
In order to prevent the overall size of the device from increasing in size, it is desired that the electronic flash device be further miniaturized, although the same can be said for cameras.

However, the converter transformer used in the converter circuit that boosts the low-voltage power supply used in electronic flash devices, and the trigger transformer used in the trigger circuit that provides high-voltage pulses to the flash discharge tube, are limited by the winding method and the shape of the core itself. The shape tends to be close to a regular cube, which is a limiting factor for miniaturization.

That is, fixed resistors and capacitors used in electronic flash devices,
Electrical components such as semiconductor components can be integrated at high density and miniaturized using hybrid thick film technology, but the transformers mentioned above have a shape close to a regular cube, which is inefficient in space and difficult to miniaturize. This is one of the reasons for the hindrance.

Therefore, the purpose of this invention is to convert transformers such as converter transformers and trigger transformers into printed coils,
In addition to making the device thinner and smaller, electrical components such as resistors, capacitors, and semiconductor components are integrated into the thinner and smaller transformers using hybrid thick film technology to further improve overall device performance. The object of the present invention is to provide an electronic flash device that can be expected to be miniaturized and improve mass productivity.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 shows a typical example of an electronic flash device, which is composed of a converter circuit section 1, a display section 2, a trigger circuit section 3, and a light emitting section 4.

FIG. 2 shows an embodiment in which the converter transformer 8 of the converter circuit section 1 of the electronic flash device shown as a typical example is made thinner.

FIG. 2A is a sectional view showing the configuration, and in the figure, 21
is the lower part of the thin pot core, and as shown in FIG. 2B, which shows the top surface thereof, it has a magnetic core 22 in the center of the bottom surface.

10' is a wire-wound coil having an air core 23 and forming the output winding 10 of the wire-wound converter transformer 8;
indicates an insulating sheet.

The insulating sheet 24 has a through hole 25 through which the magnetic core 22 passes, and on one side of the insulating sheet 24, as shown in FIG. Primary and secondary windings 9, 1
A printed coil 9', 1 forming an input winding consisting of 1
1', and the other side has a converter circuit section 1', for example.
Resistor 6, oscillation transistor 7, capacitor 12.13
It has an electrical component section 26 that is printed using hybrid thick film technology.

The winding to be printed is the primary winding 9. as shown in FIG. 2C. It is possible to print both of the input windings consisting of the secondary winding 11 to form printed coils 9' and 11', but even if only one of them is printed, the effect is that it can be made thinner and smaller than conventional devices. Needless to say, this can be obtained.

The second diagram shows a top view of electrical components such as a resistor 69 and an oscillation transistor 7 printed on an insulating sheet 24. The area indicated by diagonal lines 6' is printed to obtain a predetermined resistance value, and the capacitor 12.
Reference numeral 13 denotes a multilayer ceramic capacitor (not shown) formed into a chip, for example, indicated by diagonal lines 12'.

It is bonded to the portion shown at 13' via a conductive material.

Further, the oscillation transistor 7 and the diode 14 are formed by conductively adhering a chipped semiconductor wafer to the portions shown by diagonal lines 7' and 14' by wire bonding using a conductive material or gold wire.

Furthermore, 27 indicates the upper part of the pot core.

For each of the above components, first, the magnetic core 22 is inserted into the air core 23, and the output winding 10' is inserted into the lower part 21 of the pot core.
Next, the magnetic core 22 is inserted into the through hole 25 of the insulating sheet 24, and the insulating sheet 24 is superimposed on the output winding 10'.
Thereafter, the upper portions 27 of the pot cores are stacked and assembled to complete the assembly as shown in FIG. 2E.

Note that the output winding 10' is formed so that its outer circumference is approximately equal to that of the printed coil in consideration of space utilization efficiency.

The individual electrical connections of the electrical component group 26 are made via printed wiring when integrated, and the electrical connections between the electrical component group 26 and the printed coils 9' and 11' are made using commonly used through-holes. Further, the electrical connection between the output winding 10', the printed coil of the insulating sheet 24, and the electrical component group 26 is made by the through-hole technique as shown in FIG. 2C.

FIG. 3 shows another embodiment of the present invention, in which a trigger transformer is attached to the above-mentioned insulating sheet.

Figure 3A shows the printed coil 9' of the converter transformer 8.
, 11' and a printed coil 19' formed by printing the primary winding 19 of the trigger transformer 18 on an insulating sheet 24', which is an extension of the insulating sheet on which the electrical component group 26 was formed, and resistors 15, 17, . An electrical component group 28 is formed in which a capacitor 16 and the like are integrated.

These printed coils 9', 11', and 19' are the third
As shown in the plan view of FIG. B, a through hole 30 is provided in the center of the printed coil 19'.

The printed coils 9' and 11' of the insulating sheet 24' configured as described above form the converter transformer on the left side of the figure as described above, and the printed coil 19' that forms the primary winding of the trigger transformer 18. is a wire-wound secondary winding 20' of the trigger transformer 18 having an air core 29.
are superimposed as shown.

Thereafter, the upper portion 31 having the magnetic core 32 is overlaid so that the magnetic core 32 passes through the through hole 30 and the air core 29 to complete the structure.

This trigger transformer normally emits high-frequency damped vibrations of about 0.5 to 2 MHz, and although it is more efficient if it has a magnetic core, it is not possible to generate enough high-frequency pulses to excite the flash discharge tube even without a magnetic core. It can also be generated.

FIG. 4 shows an example of this. As shown in the figure, the primary winding 19 of the trigger transformer 18 is printed and the printed coil 19' is applied on one side of the insulating sheet 24', and the trigger transformer 18 is placed on the other side. This is achieved by attaching the secondary winding 20'.

FIG. 5 shows another embodiment of the present invention in which a converter transformer and a trigger transformer are housed in one pot core.

In the figure, 33 indicates the lower part of the pot core, which has a magnetic core 34 of the converter transformer 8, a magnetic core 36 of the trigger transformer 18, and a separation part 35 that isolates the converter transformer and the trigger transformer. 5B.

Inside the pot core 34 is an output winding 10 as described above.
', the secondary winding 20' is inserted into each magnetic core 34, 36, and the insulating sheet 24' on which the printed coils 9', 11', and 19' are applied is superimposed, and finally the upper part 37 of the pot core is superimposed. be intimidated by this.

Of course, it is also possible to integrate the above-mentioned electrical components on this insulating sheet 24' using hybrid thick film technology, and electrical connection with each electrical component can be made using through-hole technology.

In each of the above embodiments, a typical electric flash device has been described, but other devices may also be used, such as a device with a constant voltage circuit that keeps the charging voltage of the main discharge capacitor constant, or a device that automatically emits light by receiving reflected light from the subject. The present invention can be similarly applied to an automatic light control device having a light amount control circuit that can control the amount of light, and these constant voltage circuits and light amount control circuits can be integrated into a thin transformer or the like.

As described above, the present invention makes the device smaller by making the transformers, which have conventionally had poor space efficiency, thinner and smaller.

By integrating electrical components such as semiconductors into the above-mentioned thin and compact transformers, the device can be made even more compact.

Furthermore, conventionally, in most transformers, the primary, secondary, output, etc. windings are sequentially wound around the magnetic core, and this work is troublesome and hinders mass production and cost reduction. However, the transformers according to the present invention have a configuration in which, for example, one winding is printed and formed and only the other winding is wire-wound, which simplifies the work and allows for greater mass production than ever before, reducing costs. An extremely useful electronic flash device can be provided.

[Brief explanation of the drawing]

FIG. 1 shows a circuit diagram of a typical electronic flash device, FIGS. 2A, B, C, D, and E show converter circuits of an embodiment of the present invention, and FIGS. 3A, B, C1 Figure 4, Figure 5 A, B
FIG. 3 is a diagram showing another embodiment of the converter circuit section of the present invention.

Claims (1)

[Scope of utility model registration request] A converter transformer with an input winding and an output winding consisting of primary and secondary windings, an oscillation transistor, a resistor, and a capacitor convert the low voltage power supply into high voltage and charge the main discharge capacitor. In the electronic flash device, a high-voltage pulse generated by a trigger circuit including a trigger transformer and a condenser is applied to a flash discharge tube to excite it, and charging energy of the main discharge condenser is applied to the flash discharge tube to cause the flash discharge tube to emit light. At least one of the input windings of the converter transformer is a printed coil formed by printing on an insulating sheet, and the output winding is a winding coil having an air core and an outer circumference approximately equal to the outer circumference of the printed coil. The resistor 9 is superimposed on the printed coil, and electric components such as an oscillating transistor and a capacitor are integrated on the back surface of the insulating sheet on which the printed coil is formed, and the input winding and the output winding form a closed magnetic path. An electronic flash device characterized in that the converter transformer is configured by being inserted into a magnetic core.