1. An image pick-up device comprising:
a camera body;
a lens barrel mounted to the camera body;
a pop-up type flash device that is retracted in the camera body when not in use and projected from the camera body when in use; and
a structure including a gripping surface provided by one side surface of the camera body and an open portion provided in a given surface that extends between a front end of the gripping surface and a front part of the lens barrel,
wherein the flash device is retracted in the camera body through the open portion when not in use and projected sideward to the outside of the camera body through the open portion when in use.
2. An image pick-up device as claimed in claim 1, in which a recording medium storage portion is provided inside the gripping surface.
3. An image pick-up device as claimed in claim 1, in which the given surface is inclined relative to the gripping surface, and in which the open portion is provided in the given inclined surface.
4. An image pick-up device as claimed in claim 1, in which the flash device comprises:
a cabinet pivotally connected to the camera body in such a manner as to be projected sideward to the outside of the camera body through the open portion when the flash device is in use and retracted in the cameral body through the open portion when the flash device is not in use;
a light emitter installed in the cabinet;
a spring providing the cabinet with a biasing force in a direction to project the cabinet outward from the open portion;
a lock mechanism that locks the cabinet at a position to close the open portion against the biasing force of the spring; and
a lock canceling mechanism that cancels the locked condition of the cabinet by operating the lock mechanism.
5. An image pick-up device as claimed in claim 4, in which the cabinet comprises:
a first plate portion that is pivoted outward from the open portion to become flush with the gripping surface when the flash device is in use and pivoted inward to close the open portion to become flush with the given surface; and
a second plate portion that extends inward from the first plate portion, the second plate portion being projected outward from the open portion and straddling a space between the first plate portion and the open portion when the first plate portion is projected outward form the open portion,
wherein the second plate portion is provided a cut window portion to which a light emitting face of the light emitter is fixed.
6. An image pick-up device as claimed in claim 4, in which the spring for providing the cabinet with the biasing force in a direction to project the cabinet outward from the open portion is a tension coil spring.
7. An image pick-up device as claimed in claim 4, in which the lock mechanism comprises:
a lift body that has at an upper part thereof a reversed V-shaped lock portion that is engageable with a locked portion provided by the cabinet;
a pair of guide shafts that guide an upward and downward movement of the lift body; and
a spring that biases the lift body upward to a position to cause the reversed V-shaped lock portion to engage with the locked portion.
8. An image pick-up device as claimed in claim 7, in which the spring for biasing the lift body upward to the position to cause the reversed V-shaped lock portion to engage with the locked portion is a compressed coil spring.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A heat exchanger tube, having at least one twisted baffle therein, each of said twisted baffles extends inside the heat exchanger tube along the axis thereof, characterized by that
said twisted baffles extend as long as at least a part of the entire length of said heat exchanger tube, and
said twisted baffles are integrated with the inner surface of said heat exchanger tube.
2. A heat exchanger tube according to claim 1, characterized by that
the twisted angle of said twisted baffles is between 100 to 360, preferably between 100 to 200.
3. A heat exchanger tube according to claims 1 or 2, characterized by that
the ratio between the axial length of said heat exchanger tube with the twisted angle 180 of said twisted baffles and the internal diameter of said heat exchanger tube is 2 to 3.
4. A heat exchanger tube according to any one of the claims 1 to 3, characterized by that
the thickness of said twisted baffles approximates to that of said heat exchanger tube;
in every cross section of said heat exchanger tube, the transition zone from the surface of said twisted baffles to the surface of said heat exchanger tube, and vice versa, is in the shape of a concave circular arc.
5. A heat exchanger tube according to any one of the claims 1 to 4, characterized by that
said the heat exchanger tube with a twisted baffle integrated with its inner surface is made by means of
smelting the raw material in the vacuum condition, and
precision casting with the model being burning away.
6. A cracking furnace tube, characterized by that
said cracking furnace tube uses at least one said heat exchanger tube according to the present invention,
any two of said heat exchanger tubes are separated from each other in at least one section of the radiation heating furnace tube, and
the distance between the two adjacent said heat exchanger tubes is at least 5 pitches.
7. A cracking furnace tube according to claim 6, characterized by that the distance between the two adjacent said heat exchanger tubes is 15 to 20 pitches.
8. A tubular heat furnace, characterized by that
said tubular heat furnace uses at least one said heat exchanger tube according to the present invention,
any two of said heat exchanger tubes are separated from each other in at least one section of the radiation heating furnace tube, and
the distance between the two adjacent said heat exchanger tubes is at least 5 pitches.
9. A tubular heat furnace according to claim 8, characterized by that
the distance between the two adjacent said heat exchanger tubes is 15 to 20 pitches.
10. A method for making the heat exchanger tube according to the present invention, characterized by that
said method includes the steps of
smelting the raw material in the vacuum condition, and
precision casting with the model being burning away, wherein,
the model used for forming the twisted baffle is composed of a plurality of parts, and
a profile in conformity with the surface shape of said twisted baffle is formed when combining every parts of said model together.