# US 5,539,510 A · Image forming apparatus having a rotating detection lever operable in vertical and horizontal positions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,539,510 A - Document ID: US5539510A - Status: Granted - Kind: A - Application number: 08/277,991 - Filed: 1994-07-20 - Granted: 1996-07-23 - Earliest claimed: 1993-09-24 - Assignees: Fujitsu Limited - Inventors: Kunio Yamashiro; Masanori Ueda - Web page: https://patentgrep.com/patent/US5539510A ## CPC - G03G 15/6561: {for sheet registration} - G03G 2215/00012: Upright positioning as well as horizontal positioning for image forming - G03G 2215/00721: of sheet position - G03G 2215/0609: magnetic brush - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract Disclosed is an image forming apparatus capable of operating to form an image both in a horizontal installation of the apparatus and in a vertical installation thereof. The apparatus comprises a rotary endless latent image carrier; a latent image forming unit for forming a latent image on the latent image carrier; a developing unit for developing the latent image on the latent image carrier with a powder developer; and a transferring unit for transferring the developed image on the latent image carrier onto a sheet fed via a feeding path. The apparatus further comprises; a sheet detecting unit having a detection lever rotating about a rotary shaft, with a line connecting a center-of-rotation to a center-of-gravity being set at 40.degree. through 50.degree. with respect to a direction-of-gravity, and a detecting element for detecting the detection lever. With this construction, the sheet to be fed can be detected by the mechanical lever even in the horizontal installation state of the apparatus and in the vertical installation state thereof. ## Claims ### Claim 1 An image forming apparatus capable of operating to form an image both in a horizontal installation of said apparatus and in a vertical installation thereof, said apparatus comprising: a rotary endless latent image carrier; latent image forming means for forming a latent image on said latent image carrier; developing means for developing the latent image on said latent image carrier with a powder developer; transferring means for transferring the developed image on said latent image carrier onto a sheet fed via a feeding path; and sheet detecting means for detecting the sheet in the feeding path, said sheet detecting means having a detection level rotating about a rotary shaft, with a line connecting a center-of-rotation to a center-of-gravity being set at 40.degree. through 50.degree. with respect to a direction-of-gravity, and sensing means for detecting said detection lever, said detection lever arranged about said rotary shaft to be rotatable in a first direction due to a force exerted by the sheet fed via the feeding path and to be rotatable in a second direction, opposite the first direction due to the force of gravity only. ### Claim 2 (depends on 1) The image forming apparatus according to claim 1, wherein said detection lever has a front edge contacting the sheet and a rear edge detected by said detecting means. ### Claim 3 (depends on 2) The image forming apparatus according to claim 2, wherein said sheet detecting means includes a first regulation member for regulating a rotary position of said rear edge of said detection lever. ### Claim 4 (depends on 3) The image forming apparatus according to claim 3 wherein said sheet detecting means includes a second regulation member for regulating a rotary position of the front edge of said detection lever. ### Claim 5 (depends on 4) The image forming apparatus according to claim 4, further comprising a resist roller, provided in a rear stage of said sheet detecting means on the feeding path, for aligning the leading edges of the sheets and feeding the sheets toward said transferring means. ### Claim 6 (depends on 4) The image forming apparatus according to claim 4, further comprising a holding block, for holding said detection lever with the rotary shaft being centered, provided with said detecting means, said first regulation member and said second regulation member. ### Claim 7 (depends on 3) The image forming apparatus according to claim 3, further comprising a holding block, for holding said detection lever with the rotary shaft being centered, provided with said sheet detecting means and said first regulation member. ### Claim 8 (depends on 3) The image forming apparatus according to claim 3, further comprising a resist roller, provided at the rear stage of said sheet detecting means on the feeding path, for aligning the leading edges of the sheets and feeding the sheets toward said transferring means. ### Claim 9 (depends on 2) The image forming apparatus according to claim 2, wherein said sheet detecting means includes a second regulation member for regulating a rotary position of said front edge of said detection lever. ### Claim 10 (depends on 4) The image forming apparatus according to claim 4, further comprising a resist roller, provided in a rear stage of said sheet detecting means on the feeding path, for aligning the leading edges of the sheets and feeding the sheets toward said transferring means. ### Claim 11 (depends on 4) The image forming apparatus according to claim 4, further comprising a holding block, for holding said detection lever with the rotary shaft being centered, provided with said sheet detecting means and said second regulation member. ### Claim 12 (depends on 2) The image forming apparatus according to claim 2, further comprising a holding block, for holding said detection lever with the rotary shaft being centered, provided with said sheet detecting means. ### Claim 13 (depends on 2) The image forming apparatus according to claim 2, further comprising a resist roller, provided in a rear stage of said sheet detecting means on the feeding path, for aligning the leading edges of the sheets and feeding the sheets toward said transferring means. ### Claim 14 (depends on 1) The image forming apparatus according to claim 1, further comprising a resist roller, provided in a rear stage of said sheet detecting means on the feeding path, for aligning the leading edges of the sheets and feeding the sheets toward said transferring means. ### Claim 15 (depends on 1) The image forming apparatus according to claim 1, further comprising a holding block, for holding said detection lever with the rotary shaft being centered, provided with said sheet detecting means. ### Claim 16 An image forming apparatus for performing an operation to form an image on a sheet, comprising: a bottom portion serving as an installation surface for horizontally installing said apparatus; a side surface portion serving as an installation surface for vertically installing said apparatus; a rotary endless latent image carrier; latent image forming means for forming a latent image on said latent image carrier; developing means for developing the latent image on said latent image carrier with a powder developer; transferring means for transferring the developed image on said latent image carrier onto a sheet fed via a feeding path; and sheet detecting means for detecting the sheet in the feeding path, said sheet detecting means having a detection lever rotating about a rotary shaft, with a line connecting a center-of-rotation to a center-of-gravity being set at 40.degree. through 50.degree. with respect to a direction-of-gravity and sensing means for detecting said detection lever, said detection lever arranged about said rotary shaft to be rotatable in a first direction due to a force exerted by the sheet fed via the feeding path and to be rotatable in a second direction, opposite the first direction, due to the force of gravity only. ### Claim 17 An image forming apparatus capable of operating in horizontal and vertical orientations comprising: a photosensitive drum for carrying a latent image; an optical unit, for forming a latent image on said photosensitive drum; a developing unit, for developing the latent image on said photosensitive drum; a transfer unit, transferring the developed image on said photosensitive drum onto a sheet fed via a feeding path; and a detection lever, detecting the sheet in the feeding path, arranged about a rotary shaft to be rotatable in a first direction due to a force exerted by the sheet fed via the feeding path and to be rotatable in a second direction, opposite the first direction, due to the force of gravity only. ### Claim 18 (depends on 17) The image forming apparatus of claim 17, further comprising: a sensor sensing a rotational position of said detection lever. ### Claim 19 (depends on 18) The image forming apparatus of claim 18, wherein said detection lever is constructed such that a line connecting a center-of-rotation of said detection lever to a center-of-gravity of said detection lever is set at 40.degree. through 50.degree. with respect to a direction-of-gravity. ### Claim 20 (depends on 19) The image forming apparatus according to claim 19, wherein said detection lever has a front edge contacting the sheet and a rear edge detected by said sensor. ### Claim 21 (depends on 20) The image forming apparatus according to claim 20, further comprising: a first regulation member for regulating a rotary position of said rear edge of said detection lever; and a second regulation member for regulating a rotary position of said front edge of said detection lever. ### Claim 22 (depends on 21) The image forming apparatus according to claim 21, further comprising: a resist roller, provided next to a downstream side of said detection lever on the feeding path, for aligning the leading edges of the sheets and feeding the sheets toward said transfer unit. ### Claim 23 A sheet detector, detecting a sheet in a feeding path in a first orientation or in a second orientation at right angles to said first direction, the apparatus comprising: a detection lever placed adjacent to the feeding path, rotating about a rotary shaft, with a line connecting a center-of-rotation to a center-of-gravity being set at 40.degree. through 50.degree. with respect to a direction-of-gravity, said detection lever arranged about said rotary shaft to be rotatable in a first direction due to a force exerted by the sheet fed via the feeding path and to be rotatable in a second direction, opposite the first direction, due to the force of gravity only; and a sensor, sensing a rotational position of said detection lever. ### Claim 24 (depends on 23) The sheet detector according to claim 23, wherein said detection lever has a front edge contacting the sheet and a rear edge detected by said sensor. ### Claim 25 (depends on 24) The sheet detector according to claim 24, further comprising: a first regulation member for regulating a rotary position of said rear edge of said detection lever; and a second regulation member for regulating a rotary position of said front edge of said detection lever.