JPH03107879A - Laser beam printer - Google Patents

Abstract

PURPOSE:To reduce unnecessary radiation noise by transferring data in series from a control part provided on a bottom part to an operation display part provided on an upper part. CONSTITUTION:To transfer data to a display means 27 from a CPU 10, parallel data 20 outputted from the CPU 10 is converted into the serial data 22 via a parallel/serial converting means 21 which converts the parallel data to the serial data and is transferred via a cable 23. In a display means 27, the sent display data is converted to parallel data 25 via a serial/parallel converting means 24 and sent to a display control means 15. Thereby, unnecessary radiation noise is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a laser beam printer having a display device capable of displaying the number of printed sheets and the status of the device.

2. Description of the Related Art A conventional laser beam printer of this type will be described below.

FIG. 4 shows an external view of a conventional laser beam printer.

Generally, a laser beam printer is equipped with a display operation section that displays a print mode, the number of sheets to be printed, etc., and a control means that controls this operation display section. Here, 1 is an operation display section, 2 is a control board that controls the operation display section,
3 indicates a cable that connects the display board on which the operation display section 1 is mounted and the control board 2. In FIG. 4, the control board 2 is located at the top of the main body of the laser beam printer, close to the operation display section, and the length of the cable 3 is short.

FIG. 5 shows a block diagram for display control installed in the laser beam printer of FIG. 4. 17 is the display section 16
11 is a control means for controlling the display means 17. This control means 11 is equipped with a central processing unit (hereinafter referred to as CPU) that controls the display section 16 and controls each part of the laser beam printer. Reference numeral 13 indicates display data sent from the control means 11 to the display 17, and here it is sent as parallel data. 14 is a cable that transmits the display data 13, and the connector connects the control means 1.
1 and display means 17. Reference numeral 15 denotes display control means to which the display data 13 is input, and a display section 16 also sends display section data. As described above, conventionally, the data lines sent from the control means 11 to the display means 17 were parallel data, and the number of cables 14 was required to correspond to the number of data bits.

However, the laser beam printer has a portion inside thereof that becomes hot, such as a fixing device, and it is not preferable to provide the control means 11 therein. Therefore, there have been laser beam printers in which control means are provided at the bottom of the device.

Problems to be Solved by the Invention However, when the control means is disposed at the bottom of the device and the display device is disposed at the top of the device, the distance from the control means to the display device becomes long, and the distance from the control means as in the conventional case is increased. Sending display data in parallel can easily become a source of unnecessary radiation noise (the cables had to be shielded. Especially in so-called alligator-type equipment, where the exterior of the equipment is divided into upper and lower parts, the display unit is placed in the front). If the rotation axis of the exterior was installed on the rear side, the cable length would become even longer, resulting in more unnecessary radiation.Furthermore, the cable used for parallel transmission has a large number of signal lines, so However, if a thick cable was shielded, it would become even larger, which was an obstacle to miniaturizing the device.

Means for Solving the Problem In order to solve this problem, the present invention transfers data from the control section provided at the bottom of the laser beam printer to the operation display section provided at the top by serially transmitting the data. I did it like that.

Function This configuration reduces unnecessary radiation noise by performing data transfer serially, and is also effective as a noise countermeasure because the serial transfer clock is variable.

Embodiment A laser beam printer according to an embodiment of the present invention will be described in detail below.

FIG. 1 is a block diagram showing the configuration of the laser beam printer of this embodiment. Here, 10 is a display control means for the CPU 115, and 16 is a display section. Since these are the same as those in the conventional system, they are given the same numbers and their explanation will be omitted. When data is transferred from the CPU10 installed in the control means 26 to the display means 27, the CPU
When data is transferred from Ul0 to display means 27, parallel data 20, which is the output of CPU10, is first transferred as serial data 22 through cable 23 via parallel/serial conversion means 21 that converts parallel data into serial data. be done. Specifically, the cable 23 is composed of a clock line, a status line, and a serial data line for serial transfer, and the number of cable lines is reduced compared to parallel transfer. The display data sent as the serial data 22 in this way is sent to the display means 27.
At first, the data is converted into parallel data 25 via the serial/parallel conversion means 24 and sent to the display control means 15. As described above, the display data is sent to the display unit 16 through the parallel, serial, and parallel conversion process, and the data is displayed.

As described above, the control means 26 has the parallel/serial conversion means 21, and the display means 27 has the serial/parallel conversion means 2.
4 functions, and performs serial transfer as a control means 26 and a display means 27.

FIG. 2 shows a perspective view of the laser beam printer configured as described above, and FIG. 3 shows a side view thereof. here 4
is an operation display section, 5 is a paper feed cassette section, 6 is a control board, 7
indicates a cable line connecting the board of the operation display section 4 and the control board 6. In the laser beam printer shown in FIGS. 3 and 4, the paper feed cassette 5 and the operation display section 4 are arranged on the same surface in order to reduce the size of the main body and improve operability. In addition, the printing process parts such as the photosensitive drum, laser beam unit, paper transport system, fixing device, etc. are located in the center of the main body.
In order to have a degree of freedom in design without being subject to structural constraints, the control board 6 is mounted at the bottom of the main body, and as shown in FIG. It has a structure that This is because laser beam printers generally cannot be reversed for maintenance because they use toner, so maintenance is done by sliding the control board 6 backwards and taking it out as shown above. . In the above structure, the position of the connector for the cable line 7 and the control line 6 is also a sliding structure, so the connector is provided near the rear of the control board 6 so that the connector can be easily removed, as shown in FIG. Reference numeral 30 denotes an upper lid that forms the upper half of the exterior of the laser beam printer, and 31 represents a lower lid that forms the lower half of the exterior. The upper lid 30 and the lower lid 31 are connected by a hinge 32, and when performing maintenance and inspection of the inside of the print section, etc., the upper lid 3 is connected using the hinge 32 as a branch.
0 in the direction of the arrow to expose the inside. The cable line 7 passes through the hinge 32 and is placed on either the lower cover 31 or the upper cover 30.

Effects of the Invention As described above, according to the present invention, in a laser beam printer that requires a long cable to transfer data from the display control means to the display section, parallel transfer with a large number of cables and connector pins is performed. Instead, it is equipped with a device that performs parallel/serial conversion and serial/parallel conversion to perform serial transmission with fewer cables and connector pins, which has high cost benefits and is effective in reducing product costs, as well as reducing unnecessary radiation. There is little noise, the serial transfer lock frequency is variable, and it is effective as a noise countermeasure.

[Brief explanation of drawings]

FIG. 1 is a laser beam printer according to an embodiment of the present invention. FIG. 5 is an external view of a conventional laser beam printer, and FIG. 5 is a block diagram for controlling a conventional display section. 1.4...Display operation unit, 2.6...Control board, 3.
7... Cable, 5... Paper cassette, 10...
CPU. 11.26... Control means, 16... Display section, 17.
27...Display means, 21...Parallel/serial conversion means, 23...Serial cable, 24...Serial/parallel conversion means

Claims (1)

[Scope of Claims] 1) Printing means including a photosensitive drum, a laser beam unit, a paper conveyance device, and a fixing device; a lower exterior covering a lower part of the printing means; an upper exterior covering an upper part of the printing means; a display control means provided inside the lower exterior; a display means provided on the surface of the upper exterior; and a serial converter provided near the display means for converting a signal from the display control means into serial data. means, a cable for transferring serial data from the serial converting means, and a cable provided near the display means to convert the serial data coming from the serial converting means via the cable into parallel data and transmitting the serial data to the display means. A laser beam printer comprising: a parallel conversion means for supplying a parallel converter; 2) The laser beam printer according to claim 1, wherein the lower exterior and the upper exterior are rotatable about a rotation axis, and the cable is disposed near the rotation axis.