JPH0312014B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device such as an image recording device, and particularly to a paper feeding device such as an image recording device.
The present invention relates to a paper feeding device that has more than one paper feeding source and can automatically switch the paper feeding source.

2. Description of the Related Art Conventionally, some paper feeding devices in image recording apparatuses such as electronic copying machines automatically switch between a plurality of paper feeding sources. In this case, only if you have two paper sources, for example two cassettes, and each paper size is the same, the paper in the next cassette will be automatically fed out when the first cassette becomes empty. A paper feeding device is known. However, this device becomes inconvenient when a combination of paper of different quality or paper feeding direction is used. For example, if plain paper is stored in a first paper source and a second original paper of the same size is stored in a second paper source, no paper is detected while paper is being fed from the first paper source. Then, the recording paper is automatically sent out from the second paper supply source, and an accident occurs in which the recording paper is switched from plain paper to the second original paper against the operator's will. Such accidents not only impose extra work on the operator but also waste resources.

The present invention has been made in view of the above points, and an object thereof is to provide a paper feeding device that can automatically switch storage means according to the operator's will.

That is, the present invention provides a plurality of storage means (1, 2, 3) for storing paper, and a plurality of storage means (1, 2, 3) for storing paper.
3) paper feeding means (22, 23,
24), detection means (4, 5, 6) for detecting the presence or absence of paper in each storage means (1, 2, 3); designation means (12, 13, 14) for specifying in advance a storage means of If it is detected that the paper storage means is out of paper, in response to the detection output of the detection means, the paper feeding means is driven and controlled so as to switch to another storage means designated by the designation means and continue feeding paper; If the detection means detects that the selected storage means is out of paper while feeding paper by selecting a storage means that has not been designated by the designation means, the paper feed is performed in response to the detection output of the detection means. Control means (1) for inactivating the means
6) provides a paper feeding device characterized by having the following.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 shows the structure of the vicinity of a paper feeder when the present invention is applied to a copying machine whose paper feed source is a three-stage cassette. In the figure, 10 is a photosensitive drum, which includes a charging device, an exposure device, and a developing device (all not shown) as is well known.
An electrostatic latent image is formed on the photosensitive drum 10 using the photosensitive drum 10, and the image is developed. 1, 2, 3 are photosensitive drums 10
These are cassettes containing sheets of paper onto which images formed on paper will be transferred, and are arranged approximately one above the other. Each cassette 1,
Detectors 4, 5, and 6 for detecting the presence or absence of stored paper are attached to 2 and 3, respectively, and detectors 7 and 6 for detecting the size of the paper using a known method.
8 and 9 are attached. Cassette 1 and detectors 4 and 7 constitute a first paper supply source, cassette 2 and detectors 5 and 8 constitute a second paper supply source, and cassette 3
and detectors 6 and 9 constitute a third paper feed source.

As will be described later, when one of the cassettes 1, 2, and 3 is selected, one of the paper feed rollers 22, 23, and 24 associated with it is driven, and the paper stored in that cassette is passed through the guides 70, 71. ,72
The photosensitive drum 10 is sent to the photosensitive drum 10 via one of the following. Thereafter, the toner image formed on the photosensitive drum 10 is transferred to paper and fixed by the fixing device 11, and then the discharge roller 7
3,74.

FIG. 2 shows the configuration of the present invention as a block diagram, in which detectors 4, 5, 6
When detecting the presence or absence of paper, it inputs signals D _a , D _b , and D _c to a paper feed source controller (comprised of a microcomputer in this embodiment, hereinafter referred to as CPU) 16 . Similarly, size detectors 7, 8, and 9 provide signals SD _a , SD _b , and SD _c that indicate the paper size, respectively.
are sent to the CPU 16, respectively. 12, 13, 14
are snap switches that instruct the operation of the first, second, and third paper feed sources, respectively. When each switch is operated, signals SW _a , SW _b , and SW _c are input to the CPU 16 and the display devices 101 , 102 , and 103 , respectively. do.

The CPU 16 processes each input signal as described later, generates signals DR _a , DR b , and DR _c based on the input signals, and generates signals DR a , DR _b , and DR c in synchronization with the copy timing using the paper feed timing pulse applied to the terminal 25 . ,2
0, 21, thereby feeding the paper feed roller 2.
2, 23, and 24 to feed a predetermined sheet of paper. Note that the signals DR _a , DR _b , and DR _c are also sent to displays 104 , 105 , and 106 , respectively, to display which cassette is selected.

FIG. 3 shows a map of RAM within the CPU 16.
SWAFLG, SWBFLG, SWCFLG are switch 1
This is a 1-bit memory that temporarily stores the states of 2, 13, and 14. CNTA is a counter memory that counts the number of switches 12, 13, and 14 that are turned on at the same time.

Next, the operation of the apparatus of the present invention will be explained with reference to FIG. During normal operation, go to step 26 in Figure 4.
CPU internal memory bits SWAFLG, SWBFLG,
Reset SWCFLG. CPU1 at step 27
Clear the counter CNTA using memory in 6. At step 28, the output signal of switch 12 is
Check SW _a , and if switch 12 is on, set SWAFLG in step 29, and set SWAFLG in step 30.
Count up one CNTA.

In steps 31 to 36, the SW _b and SW _c signals are checked in the same way, the pressed switches are memorized, and the number of switches that are turned on at the same time is counted by CNTA. Check whether there are multiple CNTAs in step 39. If there are more than one, this means that two or more paper feed sources are specified at the same time. If two or more paper sources are specified at the same time, the device operator must select which of the multiple paper sources to feed paper from.
This will be done by the CPU 16. So the CPU
In step 16, a paper source loaded with paper is searched according to the predetermined paper source priority order, and if there is no paper in a paper source with a higher priority, the paper size of the paper source with a lower priority is selected. Determine if they match and then select the paper source. The feature of the present invention is that the designation of automatic switching is determined based on the fact that a plurality of switches 12, 13, and 14 are turned on at the same time.
It is possible to select only an arbitrary paper feed source among a plurality of paper feed sources as a target for automatic switching.

When it is determined in step 39 that multiple paper feed sources have been selected, cassettes 1, 2, and 3 are prioritized and checked in that order. In step 49, it is checked whether SWAFLG is set, and if it is set, in step 50, it is checked whether there is paper in cassette 1 using signal D _a .
If there is paper, only the signal DR _a is turned on in step 51 to enable only the drive circuit 19 to operate.

If cassette 1 is not selected or there is no paper, go to step 52. Check out SWBFLG here. If cassette 2 is specified, D _b is selected in step 53.
The presence or absence of paper in cassette 2 is checked based on the signal, and if there is paper, it is checked in step 54 whether cassette 1 is designated. If specified, step 55 will load cassette 1.
Check the paper size of and 2 by comparing the SD _a and SD _b signals. When the sizes match or when the paper feed source 1 is not designated, the signal DR _b is turned on in step 56 to enable only the drive circuit 20 to operate.

If cassette 2 is not specified, there is no paper, or the size does not match with cassette 1, SWCFLG is selected in step 57.
Find out. When SWCFLG is set, check whether there is paper in cassette 3. If there is paper, first check in step 59 whether cassette 1 is specified, and if it is specified, check if the size matches in step 60.
Check it out. If the sizes match, only the drive circuit 21 is enabled in step 64. If cassette 1 is not specified or the paper size does not match, proceed to step
It is checked in step 62 whether cassette 2 has been designated, and if so, it is checked in step 63 to see if the paper sizes match, and if they match, step 64 is performed.

In this flowchart, when all the specified cassettes or paper sources are out of paper, or when there is paper in a lower priority paper source but the paper size does not match with the higher priority specified paper source, the drive circuit is activated. No automatic switching occurs. At this time, send a signal to stop the device.
It is also possible to output it from the CPU.

If it is determined in step 39 that there is not a plurality of paper sources, a single paper source is selected. The procedure is to reset the automatic switching designation flag FLGA, check in step 42 whether the switch 12 is on, and if it is on, output the signal DR a that enables the drive circuit 19 in step 43, and then output the signal DR _a to enable the drive circuit 19 to operate. Turn off DR _b and DR _c so that the circuit is not selected. Similarly, step 44~
At step 47, each switch is checked and one of the drive circuits is made operational.

In this flowchart, when all the switches are off, the output state does not change, but if "NO" is displayed at step 46, all of DR _a to DR _c may be turned off and no paper source selected.

In the embodiment described above, the number of paper feed sources is three, but the number of paper feed sources may be two or four or more. Further, the paper feed source controller may be constructed of a logic circuit or may use a computer. Furthermore, the fourth
The flowchart shown in the figure may be configured to loop constantly, or may be performed each time an image recording operation is instructed, or whenever paper is detected to be out of the paper feed source while the paper feed source is being driven. It may be performed every time the instruction is changed by the switch 12.

Although the switches 12, 13, and 14 have been described as snap switches, it goes without saying that push button switches, touch switches, etc. may be used for alternate operation. Further, the switch signals SW _a , SW _b , SW _c may be transmitted as interface signals from outside the device.

As explained above, the paper source is configured so that you can select which paper source is to be automatically switched, so you can switch between different sizes of paper, and use the same size but different quality paper or It is possible to use a combination of paper sheets with different feeding directions, and when one paper source runs out of paper, the operator can select and feed paper of the same size and quality from other paper sources at the operator's will. It also becomes possible. Therefore, accidents such as switching between plain paper and second base paper, vertical feeding and horizontal feeding, white paper and colored paper, etc., can be prevented. Furthermore, since paper can be replenished from one paper supply source to another paper supply source while paper is being fed, continuous operation is possible.

Furthermore, since both a display for displaying the status of the switch and a display for displaying the actually operable paper feed source are provided, it is possible to easily determine the instructions given by the operator and the status of the apparatus. This is particularly effective when specifying the paper source by transmitting a signal from outside the apparatus instead of using a switch.

As described above, according to the present invention, when the operator specifies a desired storage means in advance, it is possible to automatically switch the storage means according to the operator's intention.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the structure of the feeding section in which the present invention is used, Fig. 2 is a block diagram showing the structure of the paper feed source switching device, and Fig. 3 is a RAM map in the CPU of Fig. 2. FIG. 4 is a flowchart illustrating the operation of the apparatus of the present invention. 1, 2, 3... Cassette, 4, 5, 6... Detector, 7, 8, 9... Size detector, 10... Photosensitive drum, 11... Fixing device, 22, 23, 24...
Paper feed roller.

Claims (1)

[Claims] 1. A plurality of storage means (1, 2,
3), paper feeding means (22, 23, 24) that feeds paper from the plurality of storage means (1, 2, 3); detection for detecting the presence or absence of paper in each storage means (1, 2, 3); means (4, 5, 6,) specifying means (12, 13, 14) for specifying in advance a storage means to be automatically switched from among the plurality of storage means (1, 2, 3); While feeding paper from a storage device selected from multiple specified storage devices,
When the detection means detects that the selected storage means is out of paper, the paper feeding means is configured to switch to another storage means designated by the designation means and continue feeding paper in response to the detection output of the detection means. and when the detecting means detects that the selected storing means is out of paper while feeding paper by selecting a storing means not designated by the specifying means, a detection output of the detecting means is controlled. A paper feeding device characterized in that it comprises control means (16) for responsively deactivating the paper feeding means.