FR2515782A1 - Photo-flash unit with horizontal lamp array - has multiple connector terminals adjacent one another on flat tab projecting from circuit board edge - Google Patents

Abstract

The photoflash unit comprises a horizontal linear array of flashlamps enclosed within a one-piece housing having a light-transmitting front portion folded over a back portion containing lamp-receiving cavities. A printed circuit board is joined to the housing and a pair of lead-in wires from each of the lamps are connected to conductive circuit patterns disposed solely on one side of the circuit board. The circuit patterns include multiple connector terminals located adjacent one another on a flat tab which projects from one edge of the circuit board for insertion into the receiving socket of a firing pulse source. The tab contains symmetrical apertures or recesses, which render the tab releasably engageable by sockets independent of firing pulse contacts for securely retaining the unit in the socket.

Description

FLASH LAMP DEVICE HAVING A HOLDING MEANS
The present invention relates to devices including flash lamps for photographic use and, more particularly, such devices including a card on which an electrical circuit is printed, card having an extension constituting a flat connector.

 The flashlight devices available commercially and of substantially cubic shape, include fixing means adaptable to the sockets of photographic cameras or their accessories. More specifically, these devices are extended by a holding foot provided either with a protuberang or with symmetrically distributed notches on its four sides, which, in combination with elastic fingers provided inside the corresponding socket, ensure effective locking. have been described in US patents 3,327,106, 3,602,618, 36,122,849 and 3,691,508 for example.

 The flashlight devices currently on the market, of parallelepipedal shape and known under the name flip-flasht are equipped with a card on which an electrical circuit is printed; an extension of this card constitutes a flat connector partially protected by an extension of the shoemaker. This extension also includes protrusions and notches to facilitate the elastic locking of the device in a socket. Such a device is, for example, described in American patent 3,935,442 and the locking system in American patent 3,941,447.

 In another type of device better known under the name "flash-bar", the connection means comprise an extension of the printed card forming a flat connector, and the device is kept in position in the corresponding socket only by the pressure of the elastic contacts against the terminals printed on the extension of the card.

For this device, no means is provided to ensure its locking on the socket. These connection means and the corresponding socket are, for example, described in the US patents 3,757,643 (Figure 3) and 3,598,985 (Figure 4).

 In the US patent 3,430,545, describes another type of device of parallelepiped shape. For the latter, the extension forming a flat connector comprises a plurality of terminals each corresponding to a lamp eu arranged on the front face thereof, while a common conductor is printed there transversely on its rear face. the rear face of the extension and when the device is inserted into the corresponding socket ~, a pressure contact is ensured inside the latter by means of a row of fingers provided for penetrating into the complementary notches --- so as to firmly hold the device and to avoid any inappropriate movement. In the US patent 3,473,880 describes another type of device of paralielépipèdiquo shape but the extension of which comprises only a single terminal on each side. Each terminal seems to be serrated, perhaps in order to be kept more effectively in the correct position.

 The object of the present invention is to strengthen the stability of any type of device in its socket when it is provided with an extension constituting a flat connector.

In addition, this strengthening of stability must be obtained without freezing the electrical contacts. Finally, the solution must be applicable to devices whose circuit and contact terminals are arranged on the same face of the printed card.

 The present invention therefore relates to an improvement made to photographic devices including flash lamps and provided with an extension which constitutes a flat connector adapted to ensure good stability of the device on the socket provided for this purpose on the camera.

Such a device according to the invention is simple and inexpensive to manufacture.

 According to the invention, the device includes a plurality of flash lamps having conductive wires electrically connected to an electrical circuit printed on a card. Terminals, connected to this circuit, are placed side by side on a protruding extension on one of the faces of the card. The electrical circuit is fully printed on the same side of the card.

A plurality of holding means, notches or openings, are provided on this extension at a determined interval from the terminals and ends of the card. This extension can be inserted into the socket fixed to a firing pulse generator intended to ensure electrical contact between the printed terminals and the generator. The notches or openings allow this extension to be held in place or removed independently from the electrical contacts.

 According to a preferred embodiment, the holding means symmetrically distributed over the extension, comprise two rectangular openings made symmetrically on either side of the terminals. According to a particularly preferred embodiment, the device comprises, in addition, a case in a single element whose transparent front part is folded over the rear part in which are molded the cavities forming receptacle for the lamps which are respectively arranged in the corresponding cavity, the receptacle being closed by the front part as soon as it is folded down 0 The card on which the electrical circuit is printed is integrated in the case and the extension of this card on which the terminals and the holding means are protruding outside the boot and below it.

A very simple and low-clumping device is thus obtained, including a connector which can Title locked or unlocked from the corresponding socket. The locking means are thus completely independent of the electrical terminals printed on the extension and of the corresponding contacts of the socket. Therefore, the socket and the printed circuit on the card do not require any modification. In addition, the holding means are adaptable to any device whatever the circuit printed on the mame card if the latter is printed only on one side of the latter, which applies current standards as to the arrangement of the terminals, simply leading to a lesser modification of the sockets,
The invention will be better understood and other aims, advantages and characteristics thereof will appear more clearly on reading the description, which follows to which two plates of drawings are annexed.

FIG. 1 is a partially exploded perspective view of a device according to a first embodiment of the invention, making it possible to better demonstrate the invention,
FIG. 2 is a perspective view, before folding the case into a single element in FIG. 1, but on which the lamps connected to the printed circuit have not been shown,
FIG. 3 is a schematic sectional view of the device of FIG. 1 illustrating the openings made in the extension of the card,
Figure 4 is a sectional schematic view. of another embodiment, showing notches made in the extension of the card,
FIG. 5 is a partial view in section illustrating the locking means, and
Figure 6 shows in perspective a device according to another embodiment of the invention.

 Referring now to FIG. 1, the photographic device 10 includes a horizontal row of five flashlights 11-15 each equipped with two conducting wires 11a-11b, etc., connected to a printed circuit on a card 16. By for example, the wires Il-llb, etc * .., can be soldered to the corresponding contact zones lla8-llbt, etc., provided on the printed circuit on the card 16 (see FIG. 2). The lamps 11, etc ..., are each constituted by a tubular envelope of transparent glass closed at one of its ends by a seal through which the conductive wires pass, and, at the other end, by a pinching. well veloppe is covered with a transparent protective material such as a cellulose acetate lacquer. The shell is filled with a combustible material such as zirconium foils, and a combustion promoting gas such as oxygen.

 The ignition means located inside the envelope are, for example, for a lamp operating under low voltage, a filament connecting the internal ends of the conducting wires which each comprise a pearl of a priming material arranged at the junction of the wire and the filament.

 When the lamps are placed on the card 16, the conducting wires 11a, llb, etc., are bent as shown, in such a way that the assembly of each longitudinal axis of each of the tubular envelopes constitutes a plane offset with respect to the surface of the card 16, but substantially parallel thereto.

With reference to FIG. 2, the card 16 includes a printed circuit for igniting the lamps in response to the control signals formed by voltage pulses. In the example shown in FIGS. 1 and 2, the circuit is completely printed on a saddle on the front of the card, here 11 obverse of the card, on which the conductors of the lamps are connected. The card 16 is produced by means of an insulating support such as phenolic
XP, and the circuit is obtained by chemical etching or by a photographic process, eto..Toutefoist it is preferable to print the circuit by copper stamping, which presents a significant economy. Such a process is, for example, described in American patent 3,99D,142.

 The card 16 substantially affects the shape of a rectangle, one of the long sides of which is provided with an extension 16a which is much narrower than the long side of the card from which it projects.

 Terminals 20-25 are arranged 3 close to each other on this extension. They are selectively connected to the contact zones 11a ', llb', to iSa1, 15b 'or are connected the conductor wires of the lamps, by the conductors printed on the card.

 More specifically, the terminal 20 is connected to the common printed conductor 26 to which one of the conductive wires each of the lamps is respectively connected to the contact zones 11b'-15b '.

Terminals 21-25 are each connected directly to the other lead wire of each lamp. Thus, the terminal 21 is immediately connected to the contact area 11a ', the terminal 22 to the area 12a', the terminal 23 to the area Al, the terminal 24 to the area 14a and the terminal 25 to the area 15a '. On this extension 16a of the card, the common terminal 2Q and the other five terminals 21-25 are provided to be introduced into a socket connected to a pulse generator for igniting the lamps. Such a generator can, for example , title used with the electronic circuit described in US Patent 3,618,492, and psut ttI6 incorporated in a camera or an adapter to generate a low voltage pulse in synchronicity with the shutter of the camera.

 In addition,. a strip 27, on the extension 16a, provides the necessary contact enabling the mode of operation of the camera to be switched, that is to say to adjust the latter for artificial light, as described in American patent 3.TE7. 643.

 As described in a patent application filed on the same day as the present application and under the same name, the boot of the device, which can in between be used universally, is of particularly simple design and inexpensive. More specifically, the housing is constituted by a single element 30, the front part 31, transparent, is folded over the rear part 32 provided with cavities 11'-15t where the lamps are arranged. In the example shown, there are five cavities, but they could be more numerous.

 The bootmaker, preferably, consists of a sheet molded of plastic material, such as a band of cellulose propionate with a thickness of approximately 0.8 mm, prepared by injection, by heat treatment or by any other suitable means In FIG. 2, it can be seen clearly that the sheet has a fold 33 separating the rear and front parts, and that when the case is closed, this fold 33 extends horizontally along the top of the horizontal row 11'-15 'cavities.

 To facilitate closing the case when the sheet is folded, the rear part 32 is provided with flanges 32a and 32b which extend vertically on either side of the row of cavities, 2 cantilever 32c located under this row of cavities.

The front part 31 of the shoemaker has a substantially planar transparent part 31a, as well as a cantilever 31b s1 extending under the transparent part and in a plane parallel to that of the transparent part 31a but offset with respect thereto.

In addition, the front part 31 includes a membrane alc joining the part 31a to the cantilever 31b.

 When the device is finished, the conducting wires of the lamps are soldered to the appropriate contact areas of the printed circuit on the card 16. The lamps 11-15 being respectively placed in the cavities ll'-15, the card 16 can be applied against the 'corbelling 32c of the shoemaker. The front part of the case is then folded down, the printed card 16 being disposed between the two cantilevers 31b and 32c and the lamps enclosed in their respective cavities. In this way, the transparent part is located opposite the lamps while the top and the side walls of the cavities are in contact with the transparent part of the front part of the case so as to determine individually for each of the lamps, an enclosed space. As shown, an opening is made at the bottom of each of these spaces so as to allow the introduction of the conductor wires of the lamps to connect them to the contact areas of the printed circuit on the certainly Thanks to this arrangement, as can be seen in the figure 3, the membrane 31c protects the conductive wires and the contact areas of the printed card. The edges and bottom of the case are then closed with an adhesive, for example. More precisely, the flanges 32a and 32b are brought into contact with the edges of the transparent part 31 so that an adhesive can be interposed therebetween. It is also possible to use any other means of securing.

 As shown, the edges 32a and 32b can extend from the bottom to the top of the rear part of the case to match the offset between the front periphery of the cavities and the cantilever 32c, and thus extend over the entire edge of the bootmaker. In other words, the flanges 32a and 32b come into contact with the lateral edges of the transparent part 31a of the membrane 51c and of the cantilever 3lb. At the bottom, the cantilevers 32c and 3lb are fixed respectively to the sides of the printed card for example also by means of an adhesive.

 In order to facilitate the connection between terminals 20-25 and the contacts of the socket, the extension lSade the printed card protrudes below the case. When the latter is closed, as shown in FIGS. 1 and 3, the terminals remain visible.

 In accordance with the invention, the device 10 is held in its socket by two rectangular openings 36, 38 drilled symmetrically on either side of the extension 16a of the card as shown in FIGS. 1 to 3. Preferably, these openings 36, 38 are located on either side of the printed terminals 20-25 and of the strip 27 as shown, and at a determined interval of the smallest cdté of the extension 16a. In this way, as shown in FIG. 5, when the extension is introduced into the socket 50 of the pulse generator such as a photographic camera 52, the holding fingers independent of the electrical contacts cooperate with these openings 36 and 38 to ensure the holding of the device in the socket. For example, as shown in FIG. 5, the socket is provided with two elastic fingers 54 (only one of which is shown) each having a lug 54a penetrating respectively into hole 36 or 38 of the extension 16a. The elastic fingers 54 can, for example, be modeled on the basis of plastic and title completely independent of the contacts of the electrical circuit. In addition, as shown, the lugs 54a which are provided with the fingers 54 are of trapezoidal section, their two non-parallel sides 54b st 54c establish upper and lower ramps facilitating both the insertion and removal of the device in the socket. during the introduction of the extension 16a into the socket shown in Figure 5, the lower part of the extension slides on the ramp 54b from which results in a contraction of the elastic finger 54 to the right of the drawing.

Then when the opening 36 is aligned with the lug 54a, the elastic finger 54 returns to its initial position while the lug 54a penetrates into the opening 36 (the other lug penetrating the opening 38) which locks the extension 16 and, consequently, the device 10 in the socket 50. When one wants to aster the device, it is lifted by an ascending tractlon of the extension 16a and the lower part of the opening 36 (or 38) slides on the ramp 54c, which results in a contraction of the elastic finger 54 to the right thus facilitating the removal of the device.

 FIG. 4 represents another embodiment of the invention according to which the holding means consist of notches 37 in place of the openings 36.

 Thus, FIGS. 1 and 2 the references between brackets highlight the means of holding achievable by means of two rectangular notches 37 and 39 practiced symmetrically on the part and (it-other of the terminals 20-ZS and of the contact 27, and at an interval between the printed circuit and the edges of the extension.

Obviously, the holding means can marry any other shape and be pierced with more than two openings or notches arranged, moreover, in another way, even non-symmetrical on the extension. However, in all cases, the openings or notches are pierced at a determined interval from the conductors printed on the extension in such a way that the locking mechanism is independent of the electrical contacts. In this way, it is unnecessary to provide that the electrical contacts have a particular configuration, just as the mechanism can perfectly store suitable for cards whose entire circuits and terminals are printed on only one of their faces. The means for holding inside the socket can be designed either using a movable low tick finger as shown in FIG. 5 or using a fixed lug projecting from the internal wall of the socket; in the latter case, the necessary flexibility can be provided either by a plastic material or by elastic contacts. In addition, the locking pins can be located in the socket on the same side as the electrical contacts or on the opposite side. in some cases it may be badly desirable to provide elastic fingers on each side of the sleeve.

 The lightning control circuit worked as follows as soon as terminals 20-25 were connected to a pulse source. If, by hypothesis, no lamp has yet been used, the first pulse which is applied between the terminals 20 and 21 is directly transmitted to the conductor wires of the first lamp 11, which causes the latter to ignite and the opening of the electrical circuit between its conductor wires 11a and 11b.

In the electronic circuit described in American patent 3,618,492> a monitoring function is ensured by the application of a current of maximum value determined and limited to all unused lamps. This current is generated before the ignition of one of the flashlights. In this way, a signal is obtained by which the already used lamps are switched off. This monitoring function depends on the resistance between the conductor wires of the lamps. Thus, if this circuit detects a relatively high resistance between the conductor wires of a lamp, for example greater than 50 Ohms, the terminal corresponding to this lamp is deactivated. circuit and the firing pulse is only applied to the terminals of the next lamp whose resistance between the conductor wires is low. In other words, as soon as the monitoring circuit detects a resistance lower than a certain value (for example lower at 50 Ohms), the ignition pulse is applied to the corresponding terminals,
In the present case, when the first lamp 11 has already been used, the monitoring circuit causes terminal 2L to be switched off and the connection to terminal 22 to which the lamp 12 which has not yet been used is connected. Therefore, when the firing pulse appears, it is directly applied to the lamp 12 from which the lightning results. The third pulse is applied identically between the terminals 20 and 23 to generate light from the lamp 13. The fourth pulse is applied between terminals 20 and 24 for the lamp miss 14 and the fifth pulse between terminals 20 and 25 for the lamp 15+ When flashing, the reflective metallic coating 34 allows direct the light towards the front of the device.

 Although the examples described above relate to devices equipped with five lamps arranged in a row, with a relatively narrow extension serving as a connector, it is obvious that such a housing can be produced for any type of device, including two or several lamps, for one-way or two-way use, in row or not, with an extension serving as a connector as wide or much wider than the circuit board or the overhang 32c. For example, Figure 6, there are shown ten flash lamps 40 arranged in a linear row in the housing 42 according to the invention and whose reflective cavities 44 formed in the rear part are all directed in the same direction. ten cavities and different dimensions, the housing 42 is substantially identical to the housing 30 described with reference to Figures 1 to 3. The device of Figure 6 includes a printed board whose extension 46 is wider than the main part of the card. On this extension 46, the terminals 48 protrude from the housing. On each side of the row of terminals 48, the extension is perforated with two openings or notches 47 and 49, drilled symmetrically and acting in the same way as the openings 36 and 38 described above to keep the device in its socket.

 If, as shown, only five terminals are provided, to which is added the common borna for controlling the firing of the ten lamps, it is necessary to use a special circuit.

When the lamps are connected to the circuit and the printed circuit board is put in place, the housing 42 is closed in the same way as the housing described previously with reference to FIGS. 1 and 2.

 Although only certain embodiments of the invention have been described, it is obvious that any modification made by L'Horme de l'Art in the same spirit would not depart from the scope of the present invention. By way of example, the housing 30 can be made from a material other than cellulose propionate, that is to say from any other strip of thermoplastic material; you can use a box that does not consist of a single element; the substrate of the printed card can be made of a material other than phenolic, such as for example an enamelled steel or a polystyrene, and can be an integral part of the case. Finally, it is not compulsory to print the electrical circuit with copper.

Claims (11)

 1 - Device for flash lamps for photographic use which can be connected to a pulse generator for control, said device including a card on one side of which is printed an electrical circuit and a plurality of terminals placed on one of the edges of the said card so as to connect each of the two conducting wires of each lamp to said terminals via contact zones provided on the mewe face of said card, said device being characterized in that a flat extension (16a) projecting from said lower edge of said card (16) and on which are printed csste-à-catie said terminals (2-25) is equipped with holding means (37-39) constituted both by openings and notches drilled in said extension (16a) at a determined interval from said terminals (20-25) and from said edge, said extension (16a) being able to be introduced into a socket provided on said generator for electrically connecting said bor nes in contact with said generator, said holding means allowing said extension (16a) deacon both locked and unlocked from said socket together with corresponding means (54-54a) provided in the latter and independent of said electrical contacts'  2 - Device according to claim 1, characterized in that said holding means (37-39) are arranged symmetrically on said extension (16a).  3 - Device according to the resale 2, characterized in that said extension (16a) comprises two symmetrical means (37-39) for holding.  4 - Device according to claim 3, characterized in that said two symmetrical means (37-39) for holding are constituted by two rectangular openings drilled in said extension (16a).  5 - Device according to claim 3 characterized in that said two holding means are symmetrically arranged on either side of said terminals.  6 - Device according to claim 1 characterized in that said card (16) has substantially the configuration dsun rectangls on one of the longest sides from which protrudes said extension (16a) which is at least as wide as said more long c8t6.  7 - Device according to claim 6 characterized in that said extension comprises two symmetrically maintained means arranged on either side of said terminals.  8 - Device according to claim 1 characterized in that said card has substantially the configuration of a rectangle on one of the longest sides which protrudes said prolement which is much narrower than said longer side.  9 - Living room device claim 8 characterized in that said extension comprises two symmetrically holding means arranged on either side of said terminals,  10 - Device according to claim 1 characterized in that it further includes :: - a housing consisting of a single element (30) whose front part (31), transparent, is folded over the rear part (32) molded to present a plurality of cavities (il-15 ') constituting receptacles for the lamps (11-15), - a plurality of flash lamps (11-15) placed in the said cavities (11t-15t) which closes the transparent front part, - a printed circuit board, enclosed inside said housing and provided with an extension on which said terminals are printed and said said holding means, said extension projecting below said case when the latter is closed.  11 - Device according to claim 10 characterized in that a horizontal rectilinear fold (33) defines a separation between the rear part (32) and the front part (31) at the top of said housing, said rear part extending from a first cantilever below the cavities, said front part having a transparent part opposite said lamps and extending by a second cantilever under said transparent part, securing means being provided for fixing the front part to the rear part on the edges and below the said housing, so as to determine a closed receptacle for the lamps, a part of the said card being pinched between the said first and second cantilevers, so that the said projection protrudes outside the says box and below it.