Camera incorporating electronic flash unit
BACKGROUND OF THE INVENTION 
     The present invention relates generally to a compact or small size camera having a built in electronic flash and it relates more particularly to a low profile, compact camera. 
     In a small size camera of the present type, the arrangement of an electronic flash device within the camera body greatly influences the size of the camera body. It has been a recent trend to reduce the sizes of the light-emitting portion and the main capacitor, both of which are essential components of the electronic flash device, although these attempts have met only partial success. However, a further reduction in the size of these components is desired for ease of accommodation in a small size camera. Meanwhile, an increase in the capacity of the cell or battery serving as a potential source for the electronic flash device is required, so as to shorten the charging interval for the main or storage capacitor to increase a flashing cycle, or for the purposes of common use as the power source for an electric shutter of the camera and for a brightness warning lamp. Thus, it follows that a bulky cell has to be positioned in the camera. 
     A camera itself should desirably be compact in size from the viewpoints of portability, convenience and operability. However, the electronic flash device including the battery or cell, which occupies a large space in the camera body, imposes a limitation on any reduction in the size of the camera body, and an increase in the capacity of the cell leads to an accompanying increase in the size of the camera body. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a camera incorporating an electronic flash unit, which camera is compact in size due to improved disposition of a cell compartment for receiving an electric battery of one or more electric cells for the electronic flash unit. 
     Another object of the present invention is to provide a camera of the above type which is compact in size but in which the so-called red-eye phenomenon is less conspicuous. 
     To accomplish the above objects, a camera of the present invention comprises a camera housing of substantially rectangular parallelopiped configuration which is thin in the upward and downward direction and which delineates a space or cavity therein. An electronic flash unit and a cartridge compartment means for receiving an exchangeable film cartridge are disposed within the camera housing respectively at a substantially forward part and at a substantially rear part of the camera housing space whereas a battery compartment means of an elongate shape for receiving an electric battery of one or more electric cells for the electronic flash unit is also disposed within the camera housing between the electronic flash unit and the cartridge compartment means and is at an oblique angle to the forward and rearward direction. The cartridge compartment and the electronic flash unit are mutually separated or out of register in the forward and rearward direction such that the distance between the cartridge compartment and the electronic flash unit in the lateral direction is shorter than the width of the battery compartment. 
     With the above disposition of components, the size of the camera housing in the lateral direction is shortened as compared with the case where the battery compartment means of an elongate shape is disposed within the camera housing between the electronic flash and the cartridge compartment means so as to orient the longitudinal axis thereof in the forward and rearward direction (see FIG. 2) or in the case where the battery compartment means of an elongate shape is disposed within the camera housing at a side of the cartridge compartment means and behind the electronic flash unit so as to orient the longitudinal axis thereof in the lateral direction (see FIG. 3) because the total distance between the cartridge compartment means and the electronic flash unit is shortened as compared with the above cases. 
     In addition, so-called red-eye phenomenon will become inconspicuous as compared with the case where the battery compartment means of an elongate shape is disposed within the camera housing at an outer side of the electronic flash unit, i.e., where the electronic flash unit is disposed between the battery compartment means of an elongate shape and the cartridge compartment means (see FIGS. 1(a) and 1(b)) because the distance between the electronic flash unit and the camera objective lens disposed in front of the cartridge compartment means is lengthened as compared with the above case. 
     In a preferred embodiment of the present invention, the battery compartment means has an indicating symbol or indicia for indicating the polarity of the electric battery and the manner of insertion of the electric battery into the compartment means. The indicating symbol is disposed at an inner wall of the cell compartment means adjacent to its rear end exposed to the exterior of the camera housing so as to be observed from the rear side of the camer housing. As the cartridge compartment means is inclined with respect to the forward and rearward direction, the indicating symbol can be observed from the rear side of the camera housing. Therefore, the electric cell will not be erroneously inserted into the cell compartment means with adverse polarity. 
     The above and other objects and features of the present invention will become more apparent from the following description taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1(a) is a front elevational view of a camera having a reference structure; 
     FIG. 1(b) is a plan cross-sectional view of the camera shown in FIG. 1(a); 
     FIG. 2 is a plan cross-sectional view of a camera having another reference structure; 
     FIG. 3 is a plan cross-sectional view of a camera having still another reference structure; 
     FIG. 4(a) is a front elevational view of a camera according to an embodiment of the present invention; and 
     FIG. 4(b) is a plan cross-sectional view of the camera shown in FIG. 4(a). 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 through 3 illustrate the arrangement of electronic flash devices, which are shown for comparison purposes with the arrangement of the device according to the present invention, respectively; and FIG. 4 shows the arrangement of an electronic flash device which embodies the present invention. 
     Reference will first be had to the arrangement of the electronic flash device shown for comparison with that of the present invention. FIG. 1 shows an arrangement of a small size or compact camera which houses therein a battery of a comparatively large capacity. In this camera, an objective lens 2, a film cartridge 3, a light reflecting portion 4, an electronic flash tube 5, a cell 6, a main or storage capacitor 7, a firing circuit element 8 and a finder optical system 9 are positioned within camera body 1 in a compact, closely spaced fashion. In the electronic flash device mounting portion, the main capacitor 7 is located between the cell 6 and film chamber 10 housing the film cartridge 3 therein, while the light reflecting portion 4 and electronic flash tube 5 constituting a light emitting portion, are positioned forward of main capacitor 7 as viewed in the camera body. This arrangement may minimize the width B of the camera body 1. However, when flash photography is effected, since the light reflecting portion 4 is spaced too short, a distance A from the objective lens 2, there tends to occur the red-eye phenonmenon, in which the eyes of a person or the like appear red in the picture taken, thereby failing to achieve a desired function of a camera. 
     If the length A is increased to the order of 90 mm, the red-eye phenomenon becomes the least significant. The arrangement shown in FIG. 1, however, involves a danger of the length A being appreciably less than 90 mm. 
     Since the battery chamber 11 is provided in a manner to accommodate the power source cell 6 in parallel with the optical axis of the objective lens 2, if an information plate 12 for indicating the directions of the positive and negative poles of a cell is attached to the side wall of battery chamber 11, then a user can only observe with great difficulty any indication on information plate 12. 
     In FIG. 2 battery chamber or housing 11 is provided between the film chamber 10 and an electronic flash device mounting portion in parallel with the optical axis of objective lens 2. The aforesaid electronic flash device mounting portion includes the main capacitor 7, light reflecting portion 4, electronic flash tube 5 and the firing circuit element (not shown). Light reflecting portion 4 is positioned remote from objective lens 2 thereby increasing the length A to more than 90 mm, so as to make the red-eye phenomenon inappreciable. With this arrangement, the space required for such positioning of the battery chamber 11 within the camera body is greatly increased, with the resulting increase in the width B of the camera body 1 towards light reflecting portion 4, thus failing to meet the requirement to reduce the size of the camera. Also in this arrangement, the difficulty occurs in the indication on information plate 12 so that the user can not err in placing the cell 6 into battery chamber 11, with its poles properly positioned. 
     A further arrangement is possible, as shown in FIG. 3, wherein battery chamber 11 is provided for housing a battery 6, with its longitudinal axis located at a right angle to the optical axis of objective lens 2. However, this also results in an increase in the width B of the camera body 1 towards light reflecting portion 4. Alternatively, battery 6 may be placed in battery chamber 11 from the left side of a camera, and an information plate (not shown) for indicating the direction in which a battery is to be inserted in battery chamber 11 may be attached to a cover (not shown) of battery chamber 11. However, such a simple presentation by using a simple mark alone still fails to provide satisfactory instructions to the user. 
     In view of the foregoing circumstances, a camera having a built in electronic flash device, as shown in FIGS. 4a and 4b, is provided as an embodiment of the present invention. As shown, battery 6 which has been a problem in reducing the size of the camera body is placed, with its length being positioned along the camera body transverse or forward rearward axis, the optical axis of objective lens 2 in the specifically illustrated embodiment end of battery 6 on the front side of a camera being positioned closer to the camera body medial transverse axis or the optical axis of the objective lens than the other end of battery 6 at the rear side of the camera. In addition, the battery chamber 11 is so positioned that battery 6 may be located between film chamber 10 and light reflecting portion 4 and electronic flash tube 5. Film chamber 10 and light reflecting portion 4 and flash tube 5 are out of register in the direction of the optical axis of objective lens 2 such that the distance therebetween in the lateral direction is shorter than the width of cell chamber 11. 
     Information plate 12 for indicating the direction of poles of battery 6 is attached to the inclined inner wall of battery chamber 11. It should be noted that the battery 6 may consist of a single cell or a plurality of end-to-end cells which may be individual or joined as a unit. 
     With this arrangement, the light emitting portion 4 and electronic flash tube 5 may be placed in the space left by cell chamber 11, at a minimum distance A from objective lens 2 at which distance the red-eye phenomenon becomes insignificant. Thus, the width B of the camera body 1 is appreciably reduced, and hence a compact camera of small size is achieved. Information plate 12 for the battery orientation is attached to an inclined wall surface of the battery chamber, so that one can easily view the information plate 12 from the rear of the camera thus preventing the erroneous positioning of the poles of a battery in the battery chamber. 
     Furthermore, according to the present invention, the light reflecting portion 4 and the electronic flash tube 5 may be positioned at a minimum distance, for example 90 mm, from the objective lens 2. Should the light reflecting portion 4 be designed so as to be located too close to objective lens 2, since light reflecting portion 4 and electronic flash tube 5 are positioned to the left in camera body 1, light reflecting portion 4 and electronic flash tube 5 may be slid to the left of the camera body 1 to pop out of the camera body. 
     In the embodiment shown, simple improvement in arrangement of the battery or cell chamber 11 enables a marked reduction in the size of the camera, which is free of any red-eye phenomenon, upon flash photographing, with the accompanying improved visibility of an information plate for the battery to be positioned in the battery chamber.