JPH02127324A - Sheet supply device - Google Patents

Abstract

PURPOSE:To scan an external equipment smoothly by detecting the longitudinal size in the supply direction of a sheet placed in a sheet supply tray and a lateral size perpendicular to the supply direction thereof and transmitting the detected size information to the external equipment. CONSTITUTION:When a sheet is guided by lateral guide plates 3,4 from the right and left sides and its rear end is positioned by the rear guide part 6 of a sliding tray 5, a sheet size detecting part 7 is operated by interlocking to the movement of these lateral guide plates 3,4 and the slide of a sliding tray 5. The lateral and longitudinal size of the sheet detected by the action of this sheet size detection part 7 are transmitted to the main body of a laser beam printer which is an external equipment 1.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a sheet feeding device having a sheet feeding tray that is attached to and detached from an external device such as a copying machine, a laser beam printer, or a printing machine to feed sheets. More specifically, the present invention relates to a sheet feeding apparatus in which the sheet feeding tray is capable of selectively placing and feeding sheets of various sizes, and the size of the placed sheets can be detected.

(Prior Art) Conventionally, copy paper, print paper, printing paper, etc. (hereinafter referred to as "sheets") are supplied to copying machines, laser beam printers, printing machines, etc. (hereinafter referred to as external devices) using sheet supply trays. It was. That is, in such a sheet supply tray, sheets of various sizes, such as B5. A sheet supply tray that can selectively store B4, A4, A3 size copy paper, etc. in one sheet supply tray is called a multi-purpose tray (hereinafter referred to as an MP tray).Such MP trays come in a variety of sizes. Although it is convenient to be able to place sheets of paper on the tray, it is often troublesome to check the size of the sheets loaded in the tray.

(Problem to be solved by the invention) Therefore, in the past, before operating external equipment,
P) It was difficult or time-consuming to quickly check the size of the sheet placed in the tray, and quick operations were not performed. Therefore, when the external device is a laser beam printer, for example, the sheet size is not checked before printing, and the print data area often becomes larger than the sheet size by mistake, resulting in loss of print data. In some cases, printing was performed across two pages. Such problems exist not only in laser beam printers but also in other external devices.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet feeding device that can quickly and easily confirm the sheet size as described above.

(Means for Solving the Problems) The present invention provides the vertical size in the feeding direction and the horizontal size in the direction perpendicular to the feeding direction of sheets placed on a sheet feeding tray that is attachable to and detachable from an external device and capable of feeding sheets of various sizes. This is a sheet feeding device that detects the size and transmits the detected size information to an external device.

(Function) By detecting the sheet size and transmitting it to the external device before the external device operates, the operator of the external device does not have to visually check the sheet size, and can quickly and accurately obtain size information. can be transmitted to external equipment.

(Embodiment) A first embodiment of the sheet feeding apparatus of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, an external device 1 is a laser beam printer in this embodiment. The sheet supply tray 2 is a paper supply tray that supplies sheets of print paper. The sheet placed on the sheet supply tray 2 is guided by a horizontal guide plate 3.4 that guides the sides parallel to the supply direction (upward in the figure) to prevent the sheet from being skewed. One guide plate 4 among the left and right horizontal guide plates 3 and 4 in this figure can be moved left and right (direction in the figure). Further, the rear end of the sheet is positioned by the rear guide section 6 of the sliding tray 5. This sliding tray 5 can be moved in the vertical direction (direction M) in the figure. In this way, move the sheet from the left and right sides with the horizontal guide plate 3.
4, and the rear end of the sliding tray 5 is guided by the rear guide portion 6 of the sliding tray 5.
When the sheet is positioned, the sheet size detecting section 7 is operated in conjunction with the movement of the horizontal guide plates 3 and 4 and the sliding of the sliding tray 5. The horizontal and vertical sizes of the sheet detected by the sheet size detection section 7 are transmitted to the main body of the laser beam printer, which is the external device 1.

A circuit diagram of this sheet size detection section 7 is shown in FIG.
-R8 is connected. Further, the conductive plates 8 are connected by an insulating interpolation member 9. There are two conductive plate shields 10 and 11 constructed in this manner, and they are in contact with each other through sliding contacts P in a perpendicular state. Also, one of the conductive plate shields 11 has a sliding contact Q.
The input and output terminals are connected.

The output VA to the A/D converter at the position of the sliding contact PS in FIG. 2 is as follows. In such a circuit, by setting the resistors RO to R9 to appropriate values, all combinations of the positions of the sliding contacts P and S can be determined.

Therefore, the sliding contacts P and S are connected to the horizontal guide plate 3.4 in FIG.
, if it slides according to the movement of the sliding tray 5,
The horizontal and vertical sizes of the sheet can be detected based on the output value VA.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. Note that the same parts as in FIG. 1 are given the same numbers and their explanations are omitted.

In FIG. 3, external device 1 is a laser beam printer. Within this laser beam printer main body, a laser L is oscillated from a semiconductor laser 21 as in the conventional case, and the oscillated laser L is scanned by a rotating polygon mirror 22.
A light image is formed on the surface of the photoreceptor drum 23. Since the surface of the photosensitive drum 23 is charged in advance by the primary charger 24, the portion of the optical image is formed as an electrostatic latent image. This electrostatic latent image is developed by a developing device 25 and transferred to a sheet of printing paper by the action of a transfer corona charger 26. In this manner, when forming an optical image on the photosensitive drum 23, the reflecting mirror 27 is tilted in the direction of the arrow, and the scanned laser L does not hit this reflecting mirror 27.

Now, when detecting the size of the sheet in the paper feed tray, which is the sheet feed tray 2, first, the semiconductor laser 21 is turned on, and the reflector 27 is raised in the opposite direction to the direction in which the laser beam is turned on. The light is reflected and further passed through a light diffusion filter lens 29 via a reflecting mirror 28 to illuminate the entire upper surface of the sheet supply tray 2. Thereby, the laser L of the semiconductor laser can be used for sheet size detection.

On the other hand, above the paper feed tray, which is sheet feed tray 2,
As shown in FIG. 4, a plurality of light receiving elements D1 to D9 are arranged in an abbreviated shape. The sheets S are guided by a horizontal guide plate 3 fixed on the upper surface of the sheet supply tray 2 and a movable horizontal guide plate 4. Therefore, it depends on the size of the sheet S placed on the sheet supply tray 2.

As an example in which the number and location of the light receiving elements D1 to D9 covered by the sheet are different, when the sheet is placed as shown by the dotted line in FIG. 4, the light receiving elements D2 to D8 are covered and light is blocked. Further, other light receiving elements D+ and Dq receive light. Therefore, the size of the sheet S can be detected by monitoring the ON and OFF states of the light receiving elements D1 to D9. This detected size information is transmitted to the laser beam printer, which is an external device 1, through the processing section of the sheet feeding device.

In the second embodiment described above, a plurality of light receiving elements are arranged at intervals as shown in FIG. 4, but in other embodiments, a line sensor or the like is used to continuously measure the size of the sheet. It is also removable to detect.

A third embodiment of the present invention is shown in FIG. 5. Parts that are the same as those in the figures showing the previous embodiment are given the same numbers and their explanations will be omitted. That is, in the second embodiment, a plurality of light receiving elements are used, and the size of the sheet is detected by covering one of the plurality of light receiving elements with the sheet S. However, five light receiving elements were used. An example is to visually recognize the size of the entire sheet using a solid-state image sensor 31 consisting of a COD image sensor or the like.

That is, as shown in the figure, a sheet S is placed on a colored sheet supply tray 2, and since the color of the sheet and the color of the sheet supply tray are different, the image of the entire sheet is captured by the solid-state image sensor 31. It is capable of binary recognition and detection of sheet size. Note that by setting the color of the sheet supply tray to black, for example, a clear contrast to the white color of the sheet can be obtained.

As described above, by detecting the size of the sheet in the horizontal direction (sheet feeding direction) and the size in the vertical direction (direction perpendicular to the feeding direction) on the sheet feeding tray, the sheet is Size information can be transmitted to external devices. Therefore, for example, when the external device is an image forming device such as a laser beam printer, it is possible to always print according to the sheet size. It is possible to prevent erroneous printing, etc. from being made. Further, the sheet size can be detected with a single detection means.

(Effects of the Invention) As explained above, according to the sheet feeding device of the present invention,
Since the size of the sheet placed on the sheet supply tray can be detected in advance, the sheet size information can be transmitted to the external device before the external device to which the sheet supply tray is attached operates. This eliminates the need for the operator of the external device to visually check the size of the sheets in the sheet supply tray, and allows the external device to scan smoothly.

[Brief explanation of the drawing]

1 is a plan view showing a state in which a sheet supply tray is attached to an external device in order to show a first embodiment of the sheet feeding device of the present invention; FIG. 2 is a circuit diagram of the sheet size detection section of FIG. 1;
3 is a sectional side view showing a second embodiment of the invention, FIG. 4 is a schematic plan view of FIG. 3, and FIG. 5 is a plan view showing a third embodiment of the invention. Explanation of symbols 1...External device 2...Sheet supply tray 3.4...Horizontal guide plate 5...Sliding tray 6...
- Rear guide section 7... Sheet size detection section 8... Conductive plate 9... Insulating interpolation member P
, Q...Sliding contact 21...Semiconductor laser 22
...Rotating polygon mirror 23...Photosensitive drum 24.
...-Charger 25...Developer 26...Transfer corona charger 27.28...Reflector 29...Light diffusion filter lenses D1 to D9...Light receiving element 31...Solid-state image sensor Tube! Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] The vertical size in the feeding direction and the horizontal size in the direction perpendicular to the feeding direction of the sheet placed on a sheet supply tray that can be attached to and detached from an external device to supply sheets of various sizes are detected, and the detected size information is transferred to the external device. Sheet feeding device that conveys the information to the user.