JPH04189250A - Carrying passage switching device - Google Patents

Abstract

PURPOSE:To prevent the rear end of a flap from being situated on a carrying passage even in the neutral state of the flap to prevent the generation of a carrying failure by providing the fixing point of an elastic member in a position apart from a carrying passage. CONSTITUTION:A carrying passage switching device is formed of a flap 32 provided on a carrying passage for recording medium and switchable to first and second states and an elastic member (toggle spring) 35 selectively holding the flap 32 in the first and second states by the elastic force. The fixing point of the elastic member 35 selectively holding the flap 32 in the first and second states by the elastic force is provided in a position apart from the carrying passage. Therefore, even if the flap 32 is laid in neutral state, the rear end of the flap 32 is never situated on the carrying passage, and the generation of a carrying failure can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a conveyance path switching device installed in a conveyance path of a laser printer or the like.

[Prior Art] Fig. 7 shows a schematic configuration of a conventionally known laser printer, in which a photosensitive drum 2 having a photoconductive layer formed on its surface is rotatable in a main body 1 of the laser printer. It is set in. Further, inside the main body 1, a charger 3, a laser scanner 4, a developer 5, and a transfer device 6 are arranged around the photosensitive drum 2. After the charger 3 uniformly charges the surface of the photosensitive drum 2, , an electrostatic latent image is formed on the surface of the photosensitive drum 2 by a laser scanner 4, and the electrostatic latent image formed on the surface of the photosensitive drum 2 is further developed into a toner image by a developing device 5.
The transfer device 6 is configured to transfer the toner image onto a recording medium. The surface of the photosensitive drum 2 having the toner image transferred to the recording medium is cleaned by a drum cleaner 7, and then the surface is neutralized by a static elimination lamp 8 in preparation for the next charging.

Further, a pickup roller 10 for taking out the recording medium stored in the paper feed cassette 9 is provided in the main body 1. It is designed to be conveyed between the transfer device 6 and the photosensitive drum 2. The surface of the recording medium conveyed between the transfer device 6 and the photosensitive drum 2 is charge-eliminated by a charge eliminator 11, and then sent to a fixing device 12.

The fixing device 12 is for fixing a toner image on a recording medium, and a pair of upper and lower conveyance rollers 13 are provided on the exit side of the fixing device 12, and a conveyance path switching device 14 is provided at the exit of the conveyance roller 13. is provided. This conveyance path switching device 14 switches the conveyance path of the recording medium, and is comprised of a plate-shaped switching member (hereinafter referred to as a flap) 15, as shown in FIGS. 8 and 9.

The flap 15 is rotatable in the vertical direction about a shaft 16, and has protrusions 17 on both sides thereof. As shown in FIGS. 9 and 10, this protrusion 17 has a toggle spring that selectively holds the flap 15 in a first state (face-up state) and a second state (face-down state) using an elastic force F. One end of the toggle spring 18 is locked, and the other end of the toggle spring 18 is locked to the locking part 20 of the frame 19.
is fixed. Note that an operating lever 21 is connected to the flap 15.

Therefore, the recording medium that has come out of the fixing device 12 is
When the paper is in the face-up state as shown in FIG. ing. Further, when the flap 15 is in a face-down state as shown in FIG. It has become.

However, in the conveyance path switching device 13 configured as described above, the shaft 16, the protrusion 17, and the locking part 20 are located almost in a straight line as shown in FIG. In a state that does not belong to any of the down states (hereinafter, this state is referred to as a neutral state), the rear end of the flap 15 is located on the transport path, resulting in a problem of transport failure. Note that FIG. 12 shows the probability that conveyance failure will occur when the flap 15 is in a neutral state.

[Problem to be solved by the invention] The present invention has been made in view of the above-mentioned problems.
The object is to provide a conveyance path switching device that can prevent the rear end of the flap from being located on the conveyance path even when the flap is in a neutral state, thereby preventing the occurrence of conveyance defects.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a flap that is provided on the conveyance path of a recording medium and can be switched between a first state and a second state, and a flap that is operated by an elastic force. The transport path switching device includes an elastic member that selectively maintains the first state and the second state, and a fixing point of the elastic member is provided at a position away from the transport path.

[Operation] According to the above configuration, the fixing point of the elastic member that selectively holds the flap in the first state and the second state by elastic force is provided at a position away from the conveyance path, so that the flap Even if the flap is in a neutral state, the rear end of the flap will not be located on the conveyance path, thereby preventing the occurrence of conveyance defects.

[Embodiment] FIG. 1 is a plan view of a conveyance path switching device showing one embodiment of the present invention, and FIG. 2 is a side view thereof. In FIGS. 1 and 2, reference numeral 31 denotes a pair of upper and lower conveyance rollers provided on the recording medium conveyance path, and a flap 32 is provided on the exit side of the conveyance roller 31. This flap 32 is connected to the shaft 3
3 as a fulcrum, and is rotatable in the vertical direction, and protrusions 34 are provided on both sides thereof. As shown in FIGS. 2 and 3, this protrusion 34 has an elastic force F applied to the flap 32.
One end of the toggle spring 35 that selectively holds the first state, which is the face-up state, and the second state, which is the face-down state, is locked, and the other end of the toggle spring 35 is connected to the locking portion of the frame 36. It is locked at 37. Note that an operating lever 38 is connected to the flap 32. Further, the locking portion 37, which is the fixing point of the toggle spring 35, is provided at a position away from the conveyance path of the recording medium.

In the conveyance path switching device configured as described above, the shaft 33, the protrusion 34, and the locking part 37 are arranged in a substantially straight line as shown in FIG. 4, and when the flap 32 is in the neutral state, as shown in FIG. As the rear end of the flap 32 stops at a position biased toward the face-up side, the rear end of the flap 32 is not located approximately halfway between the face-up position and the face-down position, thereby preventing the occurrence of conveyance defects. be able to. Incidentally, the probability of occurrence of a conveyance defect is shown in FIG. As can be seen from the figure, in this embodiment, the neutral state of the flap 32 occurs at a position biased toward the face-up side, so that the probability of occurrence of conveyance defects can be reduced.

Note that the present invention is not limited to the above embodiments.

For example, in the above embodiment, a conveyance path switching device in which the flap 32 rotates has been described, but the present invention can also be applied to a conveyance path switching device in which the flap 41 slides in the vertical direction as shown in FIG.

[Effects of the Invention] As explained above, the present invention includes a flap that is provided on the conveyance path of a recording medium and is switchable between a first state and a second state, and a flap that is switched between the first state and the second state by an elastic force. The conveyance path switching device includes an elastic member that selectively maintains the second state, and a fixing point of the elastic member is provided at a position away from the conveyance path. Therefore, since the fixing point of the elastic member that selectively holds the flap in the first state and the second state by elastic force is provided at a position away from the conveyance path, even if the flap is in the neutral state, the flap remains in the neutral state. The rear end is not located on the conveyance path, and the occurrence of conveyance defects can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conveyance path switching device showing an embodiment of the present invention, FIG. 2 is a diagram showing a flap in the device in a face-up state, and FIG. 3 is a diagram showing a flap in a face-down state. FIG. 4 is a diagram showing the neutral state of the flap, FIG. 5 is a diagram showing the probability of occurrence of conveyance defects in the same embodiment, and FIG. 6 is a side view of a conveyance path switching device showing another embodiment of the present invention. , FIG. 7 is a diagram showing a schematic configuration of a laser printer, FIG. 8 is a plan view of a conventional conveyance path switching device, and FIG. 9 is a diagram showing a schematic configuration of a laser printer.
Figure 10 shows the flap in the face-up state in the same device, Figure 10 shows the flap in the face-down state, Figure 11 shows the flap in the neutral state, and Figure 12 shows the conventional method of conveyance failure. FIG. 3 is a diagram showing the probability of occurrence. 31... Conveyance roller, 41.32... Flap, 3
5...Toggle spring. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Cause 2 / 35 \, / \--/ 31 Figure 4 ○ \t Figure 8 Figure 10

Claims (1)

[Claims] A flap provided on a recording medium conveyance path and switchable between a first state and a second state, and an elastic member that selectively holds the flap in the first state and the second state by elastic force. 1. A conveyance path switching device comprising a conveyance path switching device, characterized in that a fixing point of the elastic member is provided at a position away from the conveyance path.