JPH01318170A - Image reader - Google Patents

Abstract

PURPOSE:To attain various image communication processing without increasing the number of signal lines on an interface and to reduce the cost of a device by selectively inputting/outputting two or more control signal lines for a prescribed interface signal line. CONSTITUTION:When a verify mode is specified by a command outputted from an external device 250 in an interface circuit 217, a control line (PMODE signal) of a register 222 is set up to 'L' to select an OSC 1207 and a BUSY signal is validated. When a printer synchronizing mode is specified, the PMODE signal is turned to 'H', an OSC 2208 is selected and a synchronizing signal (BD) input is validated. Since plural different signals can be switched and inputted/outputted by the same interface signal line, various image communication processing can be executed without increasing the number of signal lines and the cost of the device can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading device that can be connected to an external processing device such as a host computer or a printer.

[Prior Art] Conventional image reading devices use CCDs, photoelectric conversion elements, etc. relative to the surface of the original! 3. A means for reading the image and printed information of a document by scanning and converting it into an electrical signal, a processing means for converting the electrical signal into a binary or multi-valued parallel signal, and a processing means for converting the signal into a host computer or printer. Some devices have means for transferring the information to an external device such as a laser beam printer (for example, a laser beam printer).

[Problems to be Solved by the Invention] This type of image reading device has a mote that transfers image signals to its memory in accordance with a BUSY signal from an external device (for example, a host computer), and a If an attempt is made to realize an interface circuit that can switch between transfer modes in synchronization with a synchronization signal (BD) in the main scanning direction, there is a problem in that the number of signal lines on the interface circuit increases.

An object of the present invention is to solve such problems and to connect multiple external signal processing devices (for example, mode connection for transferring image data to a host computer) without complicating the device configuration or increasing the cost. An object of the present invention is to provide an image reading device that enables mode connection for direct transfer to a printer.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an image reading device connectable to a plurality of external signal processing means, in which 2f! It is equipped with a control means for selectively inputting or outputting signals related to one or more control forms.

[Function] According to the image reading device according to the present invention, at least two or more control modes are possible by using a predetermined common interface signal line.

[Embodiment] According to an embodiment to which the present invention is applied, an input signal on the same interface line is transmitted to the host computer in response to a command from the host computer (hereinafter referred to as peripheral mode). ) is B
It is used as a synchronization signal in the main scanning direction when reading an original when image data is transferred directly to the printer (hereinafter referred to as printer synchronization mode).

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of an image reading device according to the present invention. In the figure, reference numeral 1 denotes a document image reading device that reads a document image. Reference numeral 15 includes an illumination device (lamp) PL that illuminates the document surface for reading, and a document illumination unit (optical system) movable in the direction A in the figure; 16 regulates the optical path of reflected light from the document surface. 14 is a lens for focusing the reflected light. 12 is a CCD photo sensor that photoelectrically converts focused reflected light and obtains a read signal, and is arranged in an array in correspondence with one line in the main scanning direction of the document; 13 is a CCD that drives the CCD photosensor 12; It's a driver. Reference numeral 11 represents a control unit for controlling each part, and reference numeral 17 represents a platen glass for flattening the surface of the document for reading.

Further, 18 is a document placed on the platen glass 17;
19 is a platen cover. Reference numeral 20 denotes a motor as a driving source for moving the document illumination unit in six directions, and in this example, a stepping motor is used.

FIG. 2 shows an example of the electrical configuration of this embodiment including the CCD driver 13 and control unit 11 shown in FIG. In the CCD driver 13, 201 is an amplifier that amplifies the output of the CCD photosensor 12, 202 is an A/D converter that performs D/D conversion of the amplified output to obtain, for example, a 6-bit digital output, and 203 is an A/D converter that controls the read timing. This is a CCD drive circuit that drives the CCD photosensor 12 in accordance with a timing signal supplied from the control unit 11 for regulation.

In the control unit 11 shown in FIG. 2, 217 is an interface circuit that receives control signals and receives control signals between an external device 250, such as a digital printer or a personal computer, which serves as a host device for the image reading device according to this embodiment. Outputs image signals. 218 is a CPU in the form of a microcomputer, for example, and has a ROM 219 storing a control program and a working RAM 220, and controls each part according to the procedure stored in the ROM 219.

Further, the decoder 221 decodes the address output from the CPU to select an external element, and the register 222 functions as a control signal output port.

206 is a shading control and timing signal generation circuit, and shading correction will be explained first. Before starting the reading scan, a lamp is first turned on to read data from a standard white plate (not shown) attached to the back of the index plate on the platen glass, and write it into the RAM 205 as a shading correction coefficient. R for shading correction
The OM204 stores conversion data according to the correction coefficient, and during actual reading scan, it is stored in the RAM for each main scan.
The correction coefficient is read from 205 and the A/D converter 20
The image signal input from 2 is subjected to shading correction and written to the buffer RAM 209 or 210.

05CI is an oscillator used in the error mode, and 05C2 is an oscillator used in the printer synchronization mode.
The selection is made by the PMODE signal output from the PMODE signal. Regarding the main scanning direction synchronization signal H5YNC output from the timing signal generation and shading control circuit 206 (hereinafter referred to as SHD), ■ In peripheral mode, the synchronization signal obtained by internally counting 05C1207 is output as ll5YNC, ■In printer synchronization mode, printer synchronization signal (BD) input from an external device
is output as an IISYNC signal.

The RBCK signal is the basic clock at the time of image reading, which is obtained by dividing the frequency of 05CI or 0SC2, and the FVE
The signal is a signal indicating the effective area in the sub-scanning direction, and is FH
The E signal is a signal indicating an effective area in the main scanning direction.

The buffer RAM control circuit 212 switches writing and reading of the buffer RAMs 209 and 210 for each main scanning line during image data transfer, and causes the binarization circuit 213 to output the switching.

The RAM 214 is a RAM for downloading dither matrix data, which is binarized or dithered in the binarization circuit 213 and output to the interface circuit 217 .

The excitation signal generation and serial communication control circuits 2+ and 5 are
Circuit 2 that drives the pulse motor that scans the illumination lamp
16, and also controls serial communication with external devices.

Next, the I/F circuit 217 will be explained in detail using FIG.

In FIG. 3, ■ is a binarized image signal, west is a synchronization signal of image signal 0, and ■ and 5 are synchronization signals in the main scanning direction and sub-scanning direction, respectively, during transfer. Yen/B D is an input signal from an external device, and I/B D is an input signal from an external device.
A signal line for inputting commands from an external device on the F circuit (
(not shown), when the peripheral mode is specified, the control line (PMODE signal) of the register 222 is
When the printer synchronization mode is specified, the PMODE signal is set to "Old" to enable oral input.

In the above-mentioned embodiment, the means capable of switching and inputting the two signals of the plane and the square have been described.
It is possible to increase the number of input signals to two or more by increasing the number of control lines, and it is also possible to similarly switch and output output signals.

[Effects of the Invention] As explained above, according to the present invention, it is possible to switch and input or output a plurality of different signals using the same signal line for the interface, so that the signals on the I/F It is possible to perform more diverse image communication processing without increasing the number of lines, and it is also possible to reduce costs.

[Brief explanation of the drawing]

FIG. 1 is an external view showing an embodiment of an image reading device to which the present invention is applied, FIG. 2 is a block diagram showing an example of the electrical configuration of the image reading device according to the embodiment, and FIG. 3 is a detailed diagram of the interface circuit shown in the figure; FIG. DESCRIPTION OF SYMBOLS 1... Original reading device, 11... Control unit, 12... CCD photosensor, 13... CCD driver, 14... Lens, 15... Original illumination unit, l6... Reflection mirror , 17... Platen glass, 18... Document, 19... Platen cover, 20... Stepping motor, 206... Timing signal generation and shading control circuit, 207.208... Excavator, 212 ...Buffer RAM control circuit, 213...2
Value conversion circuit, 217... Interface circuit, 250... External device.

Claims (1)

[Claims] 1) Control for selectively inputting or outputting signals relating to two or more types of control forms to a predetermined interface signal line in an image reading device connectable to a plurality of external signal processing means. An image reading device characterized by comprising means.