JPH0452740Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cartridge presence/absence detecting device for detecting whether or not a cartridge is loaded in a camera.

[Conventional technology]

2. Description of the Related Art Conventionally, cameras have been known that are provided with a dedicated switch for detecting the presence or absence of a cartridge, which detects whether or not a cartridge is loaded in the camera. on the other hand,
When loading film in a cartridge (hereinafter referred to as DX cartridge) with a code (hereinafter referred to as DX code) on the outer wall that indicates film information such as ISO sensitivity and number of shots that can be taken, the above will occur.
There are also known cameras that have a built-in contact that connects to the DX code so that film information can be read electrically.

[Problem that the invention attempts to solve]

If a dedicated switch for detecting the presence or absence of a cartridge is additionally provided in the camera having the DX code reading contact, the number of contacts will increase accordingly, leading to an increase in the number of parts and assembly cost.

The present invention was developed in view of the above problems, and by making the DX code reading contact also serve as a switch for detecting the presence or absence of a cartridge, it is possible to eliminate the need for a dedicated switch for detecting the presence or absence of a cartridge.
The presence or absence of the cartridge and the stored cartridge
This makes it possible to detect whether it is a DX Patrone or a non-DX Patrone.

[Means and actions for solving problems]

When the cartridge is not loaded, the DX code reading contact is connected to a power line such as a ground line, and this is taken out as a signal to indicate that the cartridge is not loaded in the camera.

〔Example〕

In Figure 1, DX code reading contact piece 1
4 is the DX installed on the outer wall of Patrone 5
It is disposed facing the cartridge chamber of the camera body at a position in contact with the cord 5a. The information reading circuit 1 has the reading contact piece 14 at its input end.
is connected. An exposure control circuit 2 and a cartridge presence/absence detection circuit 3 are connected to the output terminal of the information reading circuit 1. This detection circuit 3 has an output terminal connected to a film feed control circuit 4a,
It is connected to a drive circuit 4 such as a fixed ISO setting circuit 4b such as ISO100 and a film presence/absence display circuit 4c.

On the other hand, FIG. 3 is a sectional view of the vicinity of the cartridge chamber 11a of the camera body 11, and the cartridge chamber 11a is adapted to house the cartridge 5. As shown in FIG. By installing conductive/non-conductive cords on the outer wall of Patrone 5, film information such as film excess and number of shots can be expressed digitally.
A DX code 5a is provided. A contact piece fixing member 13 for fixing the contact piece 14 is fixed integrally with the camera body 11 on the opposite side (back side) of the patrone chamber 11a. This contact piece 14 is made of a conductive elastic material and is entirely covered by the fixing member 13. Further, one end thereof is fixed to the fixed member 13, and the other end is a free end 14c serving as an open/close switch. And this free end 14
A part of the c side is a U-shaped reading contact 14a, and under normal conditions, this U-shaped contact 14a protrudes into the cartridge chamber 11a from a hole 11b provided in the camera body. Further, near this hole 11b, a conductive member 15 for grounding is provided at a position facing the free end 14c, and when the U-shaped contact 14a protrudes, this free end 14c comes into contact with it. There is. In addition,
As can be seen from the rear perspective view of the patrone chamber 11a (see FIG. 2), five contact pieces 14 are provided in parallel, and each contact 14a is connected to each hole.
It projects from 1b into cartridge chamber 11a and corresponds to each bit of DX code 5a.

The operation of one embodiment of the present invention constructed as described above will be explained. When the cartridge 12 is not loaded into the cartridge chamber 11a, the U-shaped contact 14a protrudes from the hole 11b. In this case, since the free end 14c is in contact with the conductive member 15, all of the contact pieces 14 are connected to the ground line.

When the cartridge 12 is loaded into the cartridge chamber 11a, the U-shaped contact 14a is pressed by the cartridge 12 in the direction of arrow A and pushed into the position indicated by the broken line. In this position, the free end 14c is not in contact with the conductive member 15, so each contact 14a transmits the information of the DX code 5a provided on the cartridge 5 to the information reading circuit 1.

The DX code information of the cartridge thus read is decoded by the information reading circuit 1 to determine the operating state of the camera. In other words, DX Patrone 5
is loaded, ISO information determined by the DX code is introduced into the exposure control circuit 2.

On the other hand, when the cartridge 5 is not loaded, all the open/close switches 14c are on, so
All input terminals of the information reading circuit 1 are at ground potential (for example, "Low"). In response to this signal, the cartridge presence/absence detection circuit 3 outputs a signal indicating that the cartridge is not loaded, activates the presence/absence display circuit 4c, and sets the film sensitivity to a fixed ISO such as ISO100.

For example, if you enter a code containing only film sensitivity information in the DX code, all terminals are electrically connected to the common terminal under current product standards.
ISO5000, but generally film sensitivity is ISO5000
Since no film is being used, if all ISO code terminals are at ground potential, it can be interpreted as the cartridge is not loaded.

It is also possible to control other operating states of the camera by detecting whether a cartridge is not loaded from the film sensitivity reading terminal.

For example, in an auto-loading film camera that detects when the rear lid of the camera is closed and feeds the film a predetermined number of sheets, the rear lid closes only when it is detected that a cartridge is loaded using the method described above. If the film is configured to be fed in a blank manner according to the situation, the empty feeding operation of the film can be prevented when it is unnecessary.

If a cartridge without DX code information is loaded, all terminals will be open, so in this state, the information reading circuit 1 will output a predetermined film sensitivity value (for example, ISO 100). ing.

[Effects of the invention] According to the invention, without providing an independent cartridge detection switch, the DX code reading contact can be used to determine whether a cartridge is stored or not, and whether the stored cartridge is a DX cartridge or not.
DX Patrone can be detected.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a perspective view showing the mechanical part of the above embodiment, and FIG. 3 is a sectional view of the same. 5...Patrone, 14a...Reading contact.

Claims (1)

[Claims for Utility Model Registration] A camera having an information reading circuit that electrically reads a film information display code provided on the outer wall of a cartridge, which is formed of a conductor that is pressed and displaced by the wall surface of the cartridge when the cartridge is stored. and a plurality of contacts, one end of which is connected to the information reading circuit, the other end of which is used as a contact to the display cord, and the plurality of contacts connected to the power supply ground. a conductive member that is disposed at a position facing all of the contacts, is always in contact with the contacts, and is cut off from this contact when the press displacement occurs due to cartridge storage; When it comes into contact with the member, the information reading circuit detects that the cartridge is not stored, and with all the contacts cut off from the conductive member, at least one of the contact parts is connected to the ground part of the display cord. When it is in contact with the DX Patrone, store the DX Patrone, and when it is all disconnected from the ground part above, do not store it.
A device for detecting the presence or absence of a camera cartridge, characterized by detecting the storage of a DX cartridge.