JP2006253985A - Image data transmission apparatus, image reading apparatus, image processing apparatus, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform image separation and reliably transmit image data without changing the conventional configuration of a scanner and a printer engine.
Plan.
In an image forming apparatus in which an image reading apparatus 33 and an image forming apparatus 44 are arranged separately, at least one of digital image data and a timing clock is converted into a low voltage differential serial signal (LVDS), and the image data An electrical / optical conversion element 34 that converts an electrical signal into an optical signal, an optical transmission path 35 that transmits image data converted into an optical signal, and an optical / electrical conversion element that converts the transmitted optical signal into an electrical signal Are connected by an optical transmission line module 37 provided with 36, and are converted into at least one of image data and a timing clock for transmission.
[Selection] Figure 3

Description

  The present invention relates to an image data transfer apparatus in an image forming apparatus such as a scanner or an electrophotographic copying machine, and in particular, image data transferred from an image reading apparatus that converts a document image signal to a digital signal and performs image processing to the image forming apparatus. The present invention relates to a transfer device.

  Conventionally, a scanner device that is an image reading device that reads a document image exposed and scanned by a scanning optical system with a CCD line image sensor (hereinafter referred to as a CCD) and generates digital image data, and image formation that drives a printer engine based on the digital image data 2. Description of the Related Art There is a digital copying machine that includes a printer device as a device. In recent digital copying machines, a scanner separation method has been proposed in which the scanner device is separated from the print engine main body and can be freely arranged by the user from the viewpoint of appliance and welfare.

  In such a scanner device, digital image data of an original that has been exposed and scanned by a scanning optical system is transferred to a printer device. For conventional image data transmission, a low-amplitude differential serial signal (LVDS; Low Voltage Differential Signals) is used. ) Method is used. The LVDS system is relatively resistant to electrical noise and has a feature that radiation noise caused by harmonics of an operation clock can be reduced.

  However, in the case of the scanner separation, since the transmission path of the image data signal becomes significantly long, the influence of electrical noise and radiation noise cannot be suppressed despite the use of the LVDS method, and thus the image data Transmission errors and unwanted electromagnetic waves may occur.

  As described above, the image forming apparatus with the scanner separated is as follows. Patent Document 1 includes an image scanner, an image processing unit, a printer, a main controller that controls the operation thereof, and an interface that transmits and receives data to and from an external expansion device. An image processing apparatus is described which performs data transmission / reception via a dynamic serial data bus. In this image processing apparatus, the interface includes a circuit for detecting whether or not the external expansion device is connected based on the pulse CLOCK received from the external expansion device, and the main controller reads the detection signal and checks the connection presence or absence.

  In Patent Document 2, an input image signal is converted into digital data by an A / D converter and supplied to a packet generator. The packet generator constructs a packet with identification information for each driver. An image forming apparatus is described in which it is output to a common transmission line, and a packet decoding unit of each driving unit decodes only a packet addressed to itself and drives an element group assigned to itself.

Japanese Patent Laid-Open No. 2001-177689 JP 2000-250465 A

  By the way, as an essential measure against such electrical noise and radiation noise, a method of using optical transmission for transferring image data has been considered. Since optical transmission is not affected by electrical noise in principle and does not generate radiation noise, the above problem can be solved. However, in order to realize the above-described optical transmission, the configuration of a conventional digital copying machine, particularly a scanner and a printer apparatus, must be changed significantly.

  Accordingly, an object of the present invention is to realize optical transmission of the image data, to solve image data transmission errors and radiation noise, and to perform scanner separation without changing the conventional configuration of a copying machine, particularly a scanner and a printer engine. An object of the present invention is to provide an image data transmission device, an image reading device, an image processing device, and an image forming device that can be easily and reliably transmitted.

  The invention of claim 1 is an image data transfer device for transferring digital image data to an external device, wherein the transfer device converts at least one of the digital image data and the timing clock into a low-voltage differential serial signal and transfers them integrally. A transmission signal conversion circuit, an electric / optical conversion element for converting image data from an electric signal to an optical signal, an optical transmission medium for transmitting the image data converted into an optical signal, and the transmitted optical signal to an electric signal An image data transmission apparatus comprising: an optical / electric conversion element for conversion; and a reception signal conversion circuit for converting low-voltage operation digital image data into at least one of image data and a timing clock.

  According to a second aspect of the present invention, in the image data transfer apparatus according to the first aspect, the transmission signal conversion circuit is a serial signal conversion circuit for converting a parallel signal into a serial signal.

  The invention according to claim 3 is characterized in that the synchronization signal and timing signal related to the image data according to claim 1 or 2 are transmitted optically.

  According to a fourth aspect of the present invention, in the image reading apparatus according to the first or second aspect, at least one signal edge of a synchronization signal or a timing signal is temporally multiplexed with image data and transmitted as an optical signal. .

  A fifth aspect of the present invention is an image reading apparatus including the image data transmission apparatus according to any one of the first to fourth aspects.

  According to a sixth aspect of the present invention, in the image reading apparatus according to the fifth aspect, a drive signal output from a CPU provided at a position different from that of the image reading apparatus is transmitted to the image reading apparatus as an optical signal.

  A seventh aspect of the present invention is an image processing apparatus comprising the image reading apparatus according to any one of the fourth to sixth aspects.

  According to an eighth aspect of the present invention, there is provided an image forming apparatus comprising the image data transmission apparatus according to any one of the first to fourth aspects.

  A ninth aspect of the invention is an image forming apparatus comprising the image reading device of the fifth or sixth aspect.

  A tenth aspect of the present invention is an image forming apparatus including the image processing apparatus according to the seventh aspect.

  According to the present invention, the separation of the scanner can be easily performed without changing the conventional configuration of the copying machine, particularly the scanner and the printer engine, and the optical transmission of the image data is realized and the influence of the image data transmission error, the radiation noise, and the like. The image data can be transmitted reliably.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment, FIG. 2 is a diagram illustrating a schematic configuration of an image reading apparatus according to the embodiment, and FIG. 3 is a diagram illustrating a configuration of the image forming apparatus according to the first embodiment. FIG.

  The image forming apparatus according to this example includes a separable image reading device 33 and an image forming device 44.

An image reading unit 11 that reads an original as an analog image signal is provided in the image reading device 33, and a printer engine 43 that performs printing on paper is provided in the image forming device 44.

  The image reading unit 11 includes a timing signal generation circuit unit 32 that generates a timing signal, a CCD 28 that reads an image of a document and generates an analog signal, an analog processing circuit unit 29 that executes predetermined analog processing, and a digital signal converted from the analog signal. An A / D conversion circuit unit 30 that converts signals and a low-amplitude differential serial signal interface (LVDS interface) 31 are provided.

The image forming apparatus 44 includes an LVDS interface 38 that receives a digital signal from the LVDS interface 31, an image processing circuit unit 40 that performs predetermined processing on the digital image signal, and a processing apparatus that controls the entire image forming apparatus ( The data processing unit 26 and the printer engine 43 are connected by an interface unit (bus line) 41.

  In this example, the image reading device 33 and the image forming device 44 are configured such that the LVDS interfaces 31 and 38 are connected by the optical transmission path module 37 so that the image reading device 33 and the image forming device 44 can be arranged separately. ing. As shown in FIG. 3, the optical transmission path module 37 includes an electrical / optical conversion element 34, an optical transmission path 35, and an optical / electrical conversion element 36.

  As shown in FIG. 2, the image reading unit 11 includes a first carriage 6, a second reflecting mirror 4, and a third reflecting mirror 1, which are composed of a contact glass 1 for placing a document, a halogen lamp 2 for document exposure, and a first reflecting mirror 3. From the second carriage 7 comprising the reflecting mirror 5, the lens unit 8 for forming an image on the CCD linear image sensor 9 (CCD 17 in FIG. 1), and the white reference plate 15 for correcting various distortions due to the reading optical system and the like. Composed. During scanning, the first carriage 3 and the second carriage 7 are moved in the sub-scanning direction A by a stepping motor (not shown).

  The analog image data photoelectrically converted by the CCD 28 is output to the analog processing circuit unit 29. The analog processing circuit unit 29 performs various image processing such as sample hold processing and black level correction on the analog image data, and then outputs the analog image data to the A / D conversion circuit unit 30. The A / D conversion circuit unit 30 converts the input analog image data into 10-bit digital image data, and outputs the converted image data to the image processing circuit unit 40 via the LVDS interface 31, the optical transmission line module 37, and the LVDS interface 38. Then, after image processing such as shading correction and γ correction is performed, the image data is transmitted to the printer engine 43 via the bus line 41. Various timing clocks of the CCD 28, the analog processing circuit unit 29, the A / D conversion circuit unit 30, the stepping motor, and the halogen lamp (both not described) in the scanner device are generated and supplied by the timing signal generation circuit unit 32.

  Next, the operation of the image forming apparatus according to this example will be described. In this example, as shown in FIG. 3, the digital image data acquired by the scanner 33 is converted from an electrical signal to an optical signal, and is optically transmitted to the image forming apparatus 44 for each RGB, and then the optical signal is converted into an electrical signal. And output. At this time, an optical transmission path module 37 in which an electrical / optical conversion element 34 for converting an electrical signal to an optical signal, an optical / electrical conversion element 36 for converting an optical signal to an electrical signal, and an optical transmission path 35 are integrated. Used.

  As a result, the scanner can be easily separated only by inserting the optical transmission line module 37 without changing the configuration of the conventional digital copying machine. The LVDS interfaces 31 and 38 have a pair of two differential signal lines (+/−). In the present invention, only one of them needs to be used. The conversion element 36 may be connected to either one. In the present invention, a clock embedded type LVDS interface is used for the LVDSs 31 and 38.

  Furthermore, since an embedded clock is used in this book, there is no clock signal. That is, the clock timing is embedded in the data signal, and the clock is extracted on the reception side based on the cross point of the data signal.

  That is, as shown in FIG. 9, after the para / serial conversion on the receiver side, the transfer clock information is embedded as the first and last 2-bit data of the serial data, and transferred on the receiver side as shown in FIG. After serial / parallel conversion of the data, the clock is restored from the 2-bit data and output together with the image data. As a result, both the transfer clock and the image data can be transmitted by one set of differential signal lines.

  In this example, there is no timing skew between clock data and data data, and read image data can be transmitted stably.

  Next, a second embodiment of the present invention will be described. In this example, various synchronization signals related to image data are also optically transmitted. This will be described with reference to FIG. The basic configuration is the same as the example shown in FIG. In this example, 10-bit image data that has been A / D converted and its synchronization signal are output to the LVDS transmitter 47, subjected to para / serial conversion, and optically transmitted in the same manner as described above. Thereafter, in the LVDS receiver 52, the digital image data and various synchronization signals are again serially / paragraph-converted and output to the image processing circuit unit 54 at the subsequent stage. As described above, the synchronization signal can also be optically transmitted.

  Next, a third embodiment of the present invention will be described. In scanner separation by optical transmission, the cost for the optical transmission system may be significantly increased. This is because, for example, an optical fiber or the like used for a signal transmission path is relatively expensive. In the present invention, the number of optical transmission lines is minimized, and scanner separation can be realized easily and at low cost while maintaining image quality.

  This example is shown in FIG. The difference from the example of FIG. 4 is that 10-bit image data and its synchronization signal are input to the signal switching circuit unit 60 in the preceding stage of the LVDS 61 of the scanner device 63 and transmitted to the signal selection circuit unit 70 in the subsequent stage of the LVDS 68 of the printer device 75. Input 10-bit data. The signal switching circuit unit 60 switches and outputs the image data signal and the synchronization signal. For the synchronization signal, only the information of the assert edge is extracted (the logic for each pixel immediately before and after the assertion) and output to each bit of the 10-bit signal line of the image data. The output is output to the LVDS 61 after being delayed for a period.

  As a result, 10-bit digital image data and 10-bit equivalent sync signal assert edges (in this case, the sync signal is only divided into 10 lines in the image data signal line, and each bit has no meaning. Since the logic of each bit is 0 or all 1s, it looks like 10-bit image data of 0 or 1023 digits when viewed from the data receiving side), and is output to the LVDS 61 with the same signal line shifted by one pixel period. Will be. As a result, it is possible to transmit the information on the asserted edge of the synchronization signal superimposed on the image data.

  This is converted into a serial signal by the LVDS transmitter 61, output to the optical transmission line module 67, and optically transmitted to the printer device 75. The transmitted signal is serial / parallel converted by the LVDS receiver 68 and output to the signal selection circuit unit 70. The signal selection circuit unit 70 determines whether the transmitted signal is image data or an assert edge of a synchronization signal.

  Here, as shown in FIG. 8, the transmitted signal is converted into pixel-unit image data (digit), and the data for which two consecutive pixels change from 0 to 1024 digit or vice versa is used as the synchronization signal. Therefore, it can be distinguished from image data (since image data has MTF (Modulation Transfer Function), data change such as 0 to 1023 (or vice versa) cannot occur). After that, the synchronization signal is restored based on the transmitted assert edge information and the pulse width stored in advance in the memory, etc., and the timing is synchronized with the image data with a delay of one pixel period. The image data is output to the subsequent image processing circuit unit 71 together with the 10-bit image data.

  As described above, the minimum number of optical transmission lines used for RGB image data transmission can be reduced by superimposing the assertion edge of the synchronization signal on 10-bit image data (multiplexing in time). When there are a plurality of synchronization signals, it can be dealt with by assigning signals to each of the RGB transmission lines, and further storing the order of signals after serial communication with the CPU in a memory or the like.

  However, in the above configuration, in serial communication with the CPU that controls the entire system, a transmission error may occur in the serial communication due to electrical noise or the like, and the system may malfunction. Therefore, in the present invention, serial communication signals are also optically transmitted as shown in FIG.

  Here, an electrical / optical conversion element 84 and an optical / electrical conversion element 82 used for a serial communication signal from the scanner device 80 to the CPU 90 in the printer device 94 are added to the optical transmission line module 86 (from the scanner to the CPU). If not necessary). First, the case of serial communication from the CPU to the scanner will be described. The serial signal output from the CPU 90 passes through the signal selection circuit unit 89, is subjected to electrical / optical conversion by the added electrical / optical conversion element 84, and is sent to the scanner using the optical transmission path 85 of image data (RGB). Is transmitted.

  Thereafter, it is optical / electrically converted and input to the timing signal generation circuit unit 79. On the other hand, the case of serial communication from the scanner to the CPU will be described. The serial communication signal from the timing signal generation circuit unit 79 is output to the signal switching circuit unit 77 and transmitted to the printer device 94 via the optical transmission path 85 for image data (RGB). Here, since the image data during the serial communication is invalid, the output of the image data is stopped by the signal switching circuit unit 77 to prevent the serial signal and the image data from being mixed. The signal transmitted to the printer device 94 is output to the CPU 90 via the signal selection circuit unit 89.

  On the other hand, when the image data shown in FIG. 7 is transmitted, it is not different from the third embodiment until the optical transmission to the printer device 113 is performed. The image data (including the synchronization signal) transmitted to the printer device 113 is first input to the signal selection circuit unit 108, subjected to serial / para conversion in the LVDS 106, and then input again to the signal selection circuit unit 108 ( The image data and the synchronization signal are output to the image processing circuit unit 107 by the same processing as in the third embodiment.

  Here, the signal switching circuit unit in the scanner apparatus turns on / off image data output, and the signal selection circuit unit in the printer apparatus switches the output destination of image data and serial communication signal. This can be done by using a clock signal or an enable signal.

  According to the present invention, by using an optical transmission path module in which an electrical / optical conversion element, an optical transmission path, and an optical / electrical conversion element are integrated, and a clock embedded LVDS interface, image data and Scanner separation can be easily realized without worrying about the skew of the transfer clock and hardly changing the conventional configuration.

  In addition, according to the present invention, various synchronization signals of image data are also optically transmitted by the optical transmission path module, so that the quality of a read image such as pixel shift is reduced even when the scanner is separately disposed in a digital copying machine, for example. Can be prevented. In addition, by superimposing the edge information of the synchronization signal of the image data on the signal line of the 10-bit image data, it is possible to realize at a lower cost and with reduced complexity at the time of manufacture.

Further, according to the present invention, serial communication signals that are shifted in time from valid image data are also optically transmitted, so that even when the scanner is arranged separately in a digital copying machine, for example, the signal transmission error is eliminated and the apparatus malfunctions. Can be prevented.

  Furthermore, according to the present invention, even when the scanner is separately arranged in a digital copying machine, for example, the image data in units of pixels is temporally stable, so that the copy image has a stable image quality free from color shift and unnecessary dots. Can be maintained.

  Further, according to the present invention, for example, even when a scanner is separately arranged in a digital copying machine, it is possible to prevent deterioration in image quality in a copied image and to improve the performance of the apparatus.

  For example, even when the scanner is arranged separately in a digital copying machine, a series of image processing or image forming operations can be stabilized.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment. 1 is a diagram illustrating a schematic configuration of an image reading apparatus according to an embodiment. 1 is a block diagram illustrating a configuration of an image forming apparatus according to a first embodiment. It is a block diagram which shows the structure of the image forming apparatus which concerns on a 2nd Example. It is a block diagram which shows the structure of the image forming apparatus which concerns on a 3rd Example. It is a block diagram which shows the structure of the image forming apparatus which concerns on a 4th Example. It is a block diagram which shows the structure of the image forming apparatus which concerns on a 5th Example. 6 is a timing chart illustrating a state of transmission of an image signal of the image forming apparatus according to the embodiment. It is a timing chart which shows the signal processing of a clock embedded type LVDS interface. It is a timing chart which shows the signal processing of a clock embedded type LVDS interface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Contact glass 2 ... Halogen lamp 3 ... 1st reflective mirror 3 ... 1st carriage 4 ... 2nd reflective mirror 5 ... 3rd reflective mirror 6 ... 1st carriage 7. Second carriage 8. Lens unit 9. CCD linear image sensor 10. Image data 11. Image reading unit 15. White reference plate 26 ... Data processing unit 29. ..Analog processing circuit 30 ... A / D conversion circuit 31 ... LVDS interface 32 ... timing signal generation circuit 33 ... Image reading device (scanner)
34 ... Electric / optical conversion element 35 ... Optical transmission line 36 ... Optical / electrical conversion element 37 ... Optical transmission line module 38 ... LVDS interface 39 ... Processing device (CPU)
40: Image processing circuit unit 41: Interface unit (bus line)
43 ... Printer engine 44 ... Image forming device 47 ... LVDS transmitter 52 ... LVDS receiver 54 ... Image processing circuit unit 60 ... Signal switching circuit unit 61 ... LVDS transmitter 63 ... -Scanner device 67-Optical transmission line module 68-LVDS receiver 70-Signal selection circuit unit 71-Image processing circuit unit 75-Printer device 77-Signal switching circuit unit 79- Timing signal generation circuit unit 80... Scanner device 82... Electrical conversion element 84... Optical conversion element 85... Optical transmission path 86. ... CPU
94... Printer device 107... Image processing circuit unit 108... Signal selection circuit unit 113.

Claims (10)

In an image data transfer device for transferring digital image data to an external device,
The transfer device converts at least one of digital image data and a timing clock into a low-voltage differential serial signal, and transmits the signal integrally, and
An electrical / optical conversion element for converting image data from an electrical signal to an optical signal;
An optical transmission medium for transmitting image data converted into an optical signal;
Image data comprising: an optical / electrical conversion element for converting a transmitted optical signal into an electrical signal; and a received signal conversion circuit for converting low-voltage operation digital image data into at least one of image data and a timing clock. Transfer device. 2. The image data transmission apparatus according to claim 1, wherein the transmission signal conversion circuit is a serial signal conversion circuit for converting a parallel signal into a serial signal. 3. The image data transmission apparatus according to claim 1, wherein a synchronization signal and a timing signal related to the image data are transmitted optically. 3. The image data transmission apparatus according to claim 1, wherein at least one signal edge of the synchronization signal or the timing signal is temporally multiplexed with image data and transmitted as an optical signal. An image reading apparatus comprising the image data transmission apparatus according to claim 1. 6. The image reading apparatus according to claim 5, wherein a drive signal output from a CPU provided at a position different from that of the image reading apparatus is transmitted to the image reading apparatus as an optical signal. An image processing apparatus comprising the image reading apparatus according to claim 4. An image forming apparatus comprising the image data transmission apparatus according to claim 1. An image processing apparatus comprising the image reading apparatus according to claim 5. An image forming apparatus comprising the image processing apparatus according to claim 7.