Abstract: A heat receiver includes a casing defining a flow passage on a thermal conductive plate. The thermal conductive plate is received on an electronic component. The thermal conductive plate serves to transfer heat to coolant in the flow passage. At least two inflow nozzles extend into the casing to have discharge openings opposed to the upstream end of the flow passage. The coolant flows into the flow passage through the inflow nozzles. At least two streams of the coolant are thus generated in the flow passage. The streams widely expand or spread in the flow passage. The coolant flows through the flow passage without stagnating. The coolant can thus absorb the heat of the thermal conductive plate in an efficient manner. This results in an efficient heat absorption of the heat receiver.

Abstract: A fan is enclosed in the enclosure of an electronic apparatus. The fan discharges air out of a ventilation opening of the fan. Heat radiating fins are located in an air passage extending from the ventilation opening. A dust catcher is removably mounted on an outside surface of the enclosure into an opening of the enclosure. The dust catcher is located in the air passage between the heat radiating fins and the ventilation opening. The dust catcher serves to catch the dust in the air passage. The dust catcher is removed from the enclosure along with the dust.

Abstract: A heat receiver includes a casing defining a flow passage on a thermal conductive plate. The thermal conductive plate is received on an electronic component. An outflow nozzle has an inflow opening at the downstream end of the flow passage at a position outside the thermal conductive plate. Since the thermal conductive plate is received on the electronic component, the outflow nozzle is connected to the flow passage at a position outside the electronic component. This results in avoidance of increase in the thickness of the casing as compared with the case where the outflow nozzle directly extends into the flow passage on the thermal conductive plate.

Abstract: A first card slot extends along a first imaginary plane. A second card slot extends along a second imaginary plane parallel to the first imaginary plane. A printed wiring board is placed between the first and second imaginary planes. A first connector is mounted on the front surface of the printed wiring board. The first connector receives a first card coming through the first card slot. A second connector is mounted on the back surface of the printed wiring board. The second connector receives a second card coming through the second card slot. A guiding member defines a first guiding surface extending along the first imaginary plane and a second guiding surface extending along the second imaginary plane. A space is efficiently utilized at the back surface of the printed wiring board. The first and second cards are enclosed in the enclosure in a layered manner.

Abstract: A heat exchanger allows establishment of a flat space between first and second plates. The heat exchanger is inserted in a closed circulating loop for coolant. The flat space is allowed to have a cross-section larger than that of a cylindrical duct of the closed circulating loop. The flat space serves as a flow passage. An increased cross-section enables a reduction in the flow speed of the coolant. The coolant is allowed to slowly flow through the flat space. The coolant thus contacts with the first and second plates for a longer time. The heat of the coolant is sufficiently transferred to the first and second plates. The efficiency of heat radiation is enhanced.

Abstract: An electronic apparatus includes an enclosure enclosing a liquid cooling unit. The liquid cooling unit includes a heat receiver received on an electronic component. Heat of the electronic component is transferred to the heat receiver. The heat of the heat receiver is transferred to the coolant flowing through the flow passage of the heat receiver. The electronic component gets cooled. The coolant flows into a tank in the liquid cooling unit. The tank stores the coolant and air. The air inlet is formed in the enclosure. Fresh air is introduced into the enclosure through the air inlet. Since the tank is opposed to the air inlet, the tank is exposed to the fresh air. The heat of the coolant in the tank is thus radiated into the air. The coolant gets cooled in an efficient manner. The efficiency of heat radiation is enhanced in this manner.

Abstract: An electronic component generates heat in an electronic apparatus. The heat of the electronic component is transferred to a thermal conductive plate of a heat receiver in a liquid cooling unit. The heat is transferred to coolant from the thermal conductive plate. The temperature of the coolant rises. The heat exchanger absorbs heat of the coolant. The coolant gets cooled. The heat of the electronic component is also transferred to the printed wiring board. The heat spreads over the printed wiring board through a wiring pattern in the printed wiring board. Since the tank or/and pump is placed at a position outside the printed wiring board, the heat cannot be transferred to the tank or/and the pump. This results in prevention of rise in the temperature of the coolant in the tank or/and the pump. The efficiency of heat radiation can thus be enhanced.

Abstract: A second enclosure is coupled to a first enclosure for relative rotation around a rotation axis. The second enclosure rotates around the rotation axis in the opposite directions from a reference attitude. The second enclosure is prevented from further rotating in the first direction beyond the first rotation angle from the reference attitude. The second enclosure takes the first angular attitude. The second enclosure is also prevented from further rotating in the second direction opposite to the first direction beyond the second rotation angle from the reference attitude. The second enclosure takes the second angular attitude. The displaying unit indicates either of the first and second directions at least when the second enclosure takes the first angular attitude. The displaying unit in this manner enables the user to easily recognize an acceptable direction for the rotation of the second enclosure.

Abstract: A liquid cooling unit includes components such as first and second heat receivers, a heat exchanger, a tank and a pump in an electronic apparatus. The electronic apparatus includes a first enclosure and a second enclosure coupled to the second enclosure for relative movement. The liquid cooling unit is enclosed in the first enclosure. No component of the liquid cooling unit is enclosed in the second enclosure. The liquid cooling unit is thus incorporated in the first enclosure in a facilitated manner. This results in a reduced production cost. The liquid cooling unit can also be removed from the first enclosure in a facilitated manner.

Abstract: An enclosure has an edge for defining a window opening. A keyboard is set in the window opening. A support member attached to the enclosure from the inside of the enclosure to receive the edge of the enclosure and the keyboard. A wall stands upright from the surface of the support member at a position outside the window opening. When coffee is spilled on the keyboard, the liquid flows into a space between the keyboard and the window opening. The surface tension of the liquid serves to prevent the liquid from immediately leaking outside the window opening through the gap between the edge and the support member. The liquid then starts leaking outside the window opening through the gap. The wall of the support member blocks the liquid. It thus takes a while before the liquid flows over the wall.

Abstract: A first card slot extends along a first imaginary plane. A second card slot extends along a second imaginary plane parallel to the first imaginary plane. A printed wiring board is placed between the first and second imaginary planes. A first connector is mounted on the front surface of the printed wiring board. The first connector receives a first card coming through the first card slot. A second connector is mounted on the back surface of the printed wiring board. The second connector receives a second card coming through the second card slot. A guiding member defines a first guiding surface extending along the first imaginary plane and a second guiding surface extending along the second imaginary plane. A space is efficiently utilized at the back surface of the printed wiring board. The first and second cards are enclosed in the enclosure in a layered manner.

Abstract: A second enclosure is coupled to a first enclosure for relative rotation around a rotation axis. The second enclosure rotates around the rotation axis in the opposite directions from a reference attitude. The second enclosure is prevented from further rotating in the first direction beyond the first rotation angle from the reference attitude. The second enclosure takes the first angular attitude. The second enclosure is also prevented from further rotating in the second direction opposite to the first direction beyond the second rotation angle from the reference attitude. The second enclosure takes the second angular attitude. The displaying unit indicates either of the first and second directions at least when the second enclosure takes the first angular attitude. The displaying unit in this manner enables the user to easily recognize an acceptable direction for the rotation of the second enclosure.

Abstract: An enclosure has an edge for defining a window opening. A keyboard is set in the window opening. A support member attached to the enclosure from the inside of the enclosure to receive the edge of the enclosure and the keyboard. A wall stands upright from the surface of the support member at a position outside the window opening. When coffee is spilled on the keyboard, the liquid flows into a space between the keyboard and the window opening. The surface tension of the liquid serves to prevent the liquid from immediately leaking outside the window opening through the gap between the edge and the support member. The liquid then starts leaking outside the window opening through the gap. The wall of the support member blocks the liquid. It thus takes a while before the liquid flows over the wall.

Abstract: An electronic component generates heat in an electronic apparatus. The heat of the electronic component is transferred to a thermal conductive plate of a heat receiver in a liquid cooling unit. The heat is transferred to coolant from the thermal conductive plate. The temperature of the coolant rises. The heat exchanger absorbs heat of the coolant. The coolant gets cooled. The heat of the electronic component is also transferred to the printed wiring board. The heat spreads over the printed wiring board through a wiring pattern in the printed wiring board. Since the tank or/and pump is placed at a position outside the printed wiring board, the heat cannot be transferred to the tank or/and the pump. This results in prevention of rise in the temperature of the coolant in the tank or/and the pump. The efficiency of heat radiation can thus be enhanced.

Abstract: A liquid cooling unit includes components such as first and second heat receivers, a heat exchanger, a tank and a pump in an electronic apparatus. The electronic apparatus includes a first enclosure and a second enclosure coupled to the second enclosure for relative movement. The liquid cooling unit is enclosed in the first enclosure. No component of the liquid cooling unit is enclosed in the second enclosure. The liquid cooling unit is thus incorporated in the first enclosure in a facilitated manner. This results in a reduced production cost. The liquid cooling unit can also be removed from the first enclosure in a facilitated manner.

Abstract: A heat exchanger allows establishment of first and second flat spaces, namely parallel flat spaces along a reference. The heat exchanger is inserted in a closed circulating loop for coolant. The first and second flat spaces have a cross-section larger than that of a cylindrical duct of the closed circulating loop. These flat spaces serve as a flow passage for the coolant. An increased cross-section enables a reduction in the flow speed of the coolant. The coolant is allowed to slowly flow through the first and second flat spaces. The coolant thus contacts with the first and second plates and the third and fourth plates for a longer time. The heat of the coolant is sufficiently transferred to the first and second plates and the third and fourth plates. The efficiency of heat radiation is enhanced.

Abstract: A heat exchanger allows establishment of a flat space between first and second plates. The heat exchanger is inserted in a closed circulating loop for coolant. The flat space is allowed to have a cross-section larger than that of a cylindrical duct of the closed circulating loop. The flat space serves as a flow passage. An increased cross-section enables a reduction in the flow speed of the coolant. The coolant is allowed to slowly flow through the flat space. The coolant thus contacts with the first and second plates for a longer time. The heat of the coolant is sufficiently transferred to the first and second plates. The efficiency of heat radiation is enhanced.

Abstract: A heat receiver includes a casing defining a flow passage on a thermal conductive plate. The thermal conductive plate is received on an electronic component. An outflow nozzle has an inflow opening at the downstream end of the flow passage at a position outside the thermal conductive plate. Since the thermal conductive plate is received on the electronic component, the outflow nozzle is connected to the flow passage at a position outside the electronic component. This results in avoidance of increase in the thickness of the casing as compared with the case where the outflow nozzle directly extends into the flow passage on the thermal conductive plate.

Abstract: An electronic apparatus includes an enclosure enclosing a liquid cooling unit. The liquid cooling unit includes a heat receiver received on an electronic component. Heat of the electronic component is transferred to the heat receiver. The heat of the heat receiver is transferred to the coolant flowing through the flow passage of the heat receiver. The electronic component gets cooled. The coolant flows into a tank in the liquid cooling unit. The tank stores the coolant and air. The air inlet is formed in the enclosure. Fresh air is introduced into the enclosure through the air inlet. Since the tank is opposed to the air inlet, the tank is exposed to the fresh air. The heat of the coolant in the tank is thus radiated into the air. The coolant gets cooled in an efficient manner. The efficiency of heat radiation is enhanced in this manner.

Abstract: A heat receiver includes a casing defining a flow passage on a thermal conductive plate. The thermal conductive plate is received on an electronic component. The thermal conductive plate serves to transfer heat to coolant in the flow passage. At least two inflow nozzles extend into the casing to have discharge openings opposed to the upstream end of the flow passage. The coolant flows into the flow passage through the inflow nozzles. At least two streams of the coolant are thus generated in the flow passage. The streams widely expand or spread in the flow passage. The coolant flows through the flow passage without stagnating. The coolant can thus absorb the heat of the thermal conductive plate in an efficient manner. This results in an efficient heat absorption of the heat receiver.